May 2005 - Silicon Chip Online

Outer Front Cover
Contents
Publisher's Letter: Pacific Hydro should not be sold
Feature: Knocking on Titan’s door by Tom Moffat
Feature: Getting into Wi-Fi by Ross Tester
Project: Voice Recorder by Jim Rowe
Project: Wireless Microphone/Audio Link by Ross Tester
Feature: Hellschreiber: Sending Data Over UHF CB Radio by Stan Swan
Salvage It: An automatic stopwatch timer by Julian Edgar
Project: MIDI Theremin, Pt II by John Clarke
Feature: What’s this? Free PC Boards for Schools? by Clive Seager
Project: Pro Scoreboard, Pt III by Jim Rowe
Vintage Radio: The AWA Radiola B29 8-transistor radio with battery eliminator by Rodney Champness
Advertising Index
Book Store
Outer Back Cover

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SILICON CHIP MAY 2005 7 $ 90* 05 NZ $ 8 75 INC GST INC GST PRINT POST APPROVED - PP255003/01272 CASSINI: ISSN 1030-2662 9 771030 266001 Australia’s World-Class Electronics Magazine! Tassie’s role in the mission to Saturn’s moon SPEC SCHO IAL OLS OFFE R: Get into Wi-Fi: It’s so easy and cheap! Hellschreiber: 10 FR Send data by UHF CB E PICAX E E P r o Wireless Link: PC B ject * siliconchip.com.au Quality mic or stereo FM oards May 2005 1 ! SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.jaycar.com.au Contents Vol.18, No.5; May 2005 www.siliconchip.com.au FEATURES 8 Knocking on Titan’s door Last January the Cassini probe made a soft landing on Titan, one of Saturn’s moons. Here’s the “inside” story – by Tom Moffat. 14 Getting into Wi-Fi It’s been four years since we last looked at the subject. A lot has changed: it’s cheaper, easier and there is any amount of equipment – by Ross Tester. 41 Hellschreiber: Sending Data Over UHF CB Radio It was invented decades ago and used during WWII. Now we show you how to use it with cheap UHF CB hand-helds and shareware – by Stan Swan. Get into Wi-Fi: it’s now so simple! – Page 14. 86 What’s this? Free PC Boards for Schools? We’re launching a brand new educational series by “Mr Picaxe”, Clive Seager. To celebrate, we have 2000 experimenter’s PC boards to give away to schools! PROJECTS TO BUILD 28 Voice Recorder 25 second message recording without tapes or discs. Use it for phone messages, a voice memo pad, you name it! – by Jim Rowe 34 Wireless Microphone/Audio Link Stereo Wireless Microphone– Page 34. This stereo FM wireless microphone also makes a great quality audio link. We tested it to beyond 50 metres and it was rock solid – by Ross Tester 62 MIDI Theremin, Pt II The full constructional and setup details of our amazing new MIDI Theremin. It’s set to take the music world by storm! – by John Clarke 92 Pro Scoreboard, Pt III Now even better – it handles netball as well as basketball and other games. Putting it together and setting it up – by Jim Rowe SPECIAL COLUMNS 46 Salvage It! Hellschreiber – data via UHF CB – Page 41. An automatic stopwatch timer – by Julian Edgar 48 Serviceman’s Log Warranty claim? I don’t think so! – by the TV Serviceman 74 Circuit Notebook Automatic bathroom exhaust fan; Your probing questions answered; Automotive LED timing light; Low-voltage cutout for 12V SLA batteries 98 Vintage Radio The AWA Radiola B29 8-transistor radio with battery eliminator – by Rodney Champness DEPARTMENTS 2 Publisher’s Letter 82 Product Showcase 107 Notes & Errata 4 Mailbag 91 Book Review 109 Market Centre 61 Order Form 104 Ask Silicon Chip 111 Ad Index siliconchip.com.au 2000 blank PICAXE Experimenter’s Boards – to give away! – Page 86. This month’s cover: we sent our photographer up to Titan to catch the Cassini probe landing. . . No? OK, thanks to NASA/JPL for the superb artist’s impression. May 2005 1 SILICON CHIP www.siliconchip.com.au Publisher & Editor-in-Chief Leo Simpson, B.Bus., FAICD Production Manager Greg Swain, B.Sc.(Hons.) Technical Editor Peter Smith Technical Staff John Clarke, B.E.(Elec.) Ross Tester Jim Rowe, B.A., B.Sc, VK2ZLO Reader Services Ann Jenkinson Advertising Enquiries Lawrence Smith Benedictus Smith Pty Ltd Phone (02) 9211 8035 Fax: (02) 9211 0068 lawrence<at>benedictus-smith.com Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Julian Edgar, Dip.T.(Sec.), B.Ed, Grad.Dip.Jnl Mike Sheriff, B.Sc, VK2YFK Stan Swan SILICON CHIP is published 12 times a year by Silicon Chip Publications Pty Ltd. ACN 003 205 490. ABN 49 003 205 490 All material copyright ©. No part of this publication may be reproduced without the written consent of the publisher. Printing: Hannanprint, Noble Park, Victoria. Distribution: Network Distribution Company. Subscription rates: $83.00 per year in Australia. For overseas rates, see the subscription page in this issue. Editorial office: Unit 8, 101 Darley St, Mona Vale, NSW 2103. Postal address: PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 9979 5644. Fax (02) 9979 6503. E-mail: silchip<at>siliconchip.com.au ISSN 1030-2662 Publisher’s Letter Pacific Hydro should not be sold Australia’s biggest renewable energy company, Pacific Hydro, is under threat of takeover by a Spanish company Acciona in an $870 million deal announced at the end of March. The board of directors has unanimously recommended the takeover to its shareholder and normally, that would be that; another great Australian company sold off overseas due to the shortsightedness of Australian investment institutions. Pacific Hydro operates wind power installations both here and overseas and is an important part of Australia’s energy future. As a concerned shareholder, I would prefer it to remain Australian-owned, even though I recognise that not every foreign takeover is necessarily a bad outcome. In this case though, we might have got lucky. One Australian institution, Investment Fund Services, is not selling, at any price. They own 32% of the company and therefore they will probably stop the deal as it is conditional on 90% of the shareholders accepting it. Still, brokers are recommending that small shareholders should sell, otherwise they will be squeezed between the interests of large holders. Some commentators are hoping that Investment Fund Services will itself mount a takeover for Pacific Hydro but that is problematical since IFS is a superannuation fund and normally, such funds are unable to borrow money. The best result would be that, Acciona, finding itself thwarted by IFS, withdraws its bid, leaving Pacific Hydro to get on with business. Let us hope this happens. Glitch with Jaycar’s 2005 catalog The April 2005 issue of SILICON CHIP was accompanied by the 2005 Jaycar Engineering catalog which is very fine effort for this dynamic company. I trust that readers have enjoyed both the magazine and the catalog and that you will find the catalog a very handy reference for the coming year. However, there was a problem with the packing of these catalogs. There is a chance that some Australian readers may have received the New Zealand version of this catalog instead of the Australian version. With the exception of page 324, both versions of the Jaycar catalogs are absolutely identical except in regard to product pricing and the website identification at the bottom of the left-hand pages. Australian Jaycar catalogs have the website listed as www.jaycar.com.au while New Zealand catalogs have the website listed as www.jaycar.co.nz In addition, page 324 of the Jaycar NZ catalog gives store location maps for New Zealand, while the same page in the Australian catalog shows a range of burglar alarms. Please check your catalog to see which version you have received. If you have been unlucky enough to receive a Jaycar NZ catalog instead of the Australian version, please return it to your local Jaycar store who will replace it or call 1800 022 888 and Jaycar’s Techstore staff will send out a replacement. We apologise for any inconvenience. Leo Simpson * Recommended and maximum price only. 2 Silicon Chip siliconchip.com.au For more ideas, greater choice & better service, try MicroGram Products of the month LCD Mounted Terminal Mount this terminal on the back of a Cardbus standard LCD monitor for an Gigabit Adapter all in one solution. Supports Upgrade your laptop LAN Windows RDP and Citrix ICA protocols. Also emulates SCO, connection with this easy to DEC, Wyse terminals. install 10/100/1000Mb/s card. Cat 1239-7 $649 Cat 11465-7 $79 What’s New? DVD MPEG4 Player Plays normal DVDs and DVDs with compressed MPEG4 (DivX) content. Also supports HD TVs (up-scaling to 1260 lines). Cat 6837-7 $289 Notebook Docking Station Attach this USB 2.0 device to any notebook or PC and have access to the following ports. 2 x PS/2, Serial (DB9), Parallel (DB25), LAN (10/100), Audio In + Out, 2 x USB 2.0 Cat 2937-7 $159 Multi-Homed ADSL Routers These ADSL routers allow connection to multiple ISPs. Enhance reliability and increase your ADSL capacity. Cat 10145-7 Two ADSL feeds $399 Cat 10139-7 Four ADSL feeds $519 Cordless Mouse No Batteries Required This cordless mouse draws its power from its RFID embedded mouse mat. With no batteries the mouse is extremely lightweight and glides very smoothly across the mat. Cat 9263-7 $49 Skype Phones KVM Switches Control Multiple PCs with one console (keyboard, monitor and mouse). Cat 11654-7 Two Way $99 Cat 11655-7 Four Way $149 Cat 11656-7 Eight Way $499 USB to Serial Plugs into a USB port to provide multiple serial ports. Cat 2828-7 One port $54 Cat 2852-7 Two port $119 Cat 2851-7 Four port $349 Skype is free software that allows the user to make free Skype-to-Skype calls and calls to landline phones around the world from approx 3c a min with no flagfall. www.skype.com . MicroGrams USB phones feature full integration with Skype. Cat 10165-7 Desktop $129 Cat 10166-7 Mobile $119 Cat 10167-7 Handset $69 Front Access Bay Fit this unit into a 5¼" bay and have convenient access to a 6-in-1 memory card reader, 3 USB 2.0 ports, 2 Firewire ports, Audio In/Out, 12v and 5v Power Output. Cat 6765-7 $129 AV Sender Transmit Video and Audio signals (RCA) up to 100m over a wireless link. Also relays back an Infrared remote control. Cat 11808-7 $159 Pentium 4 with ISA A quality industrial motherboard with two ISA slots. It is based on the Intel 875P chipset and supports S478 Prescott processors. Cat 17086-7 $799 RFID Controller Bluetooth Barcode Scanner PCI-X 3.3v Serial Card USB to VGA A cordless CCD scanner with a minimum 10 metre RF range. Great for retail outlets or small warehouses. Includes Bluetooth dongle. Cat 1008178-7 $799 Add two RS232 ports to systems with low voltage 32 or 64bit PCI slots. Cat 2870-7 $149 Plugs into a USB 2.0 port and allows the user to extend their desktop over two screens (or three screens if already using a dual head video card). Cat 15156-7 $199 Luminescent Keyboards Digital TV Tuner USB Sharing Switch A soft, even, blue light behind the keys makes them perfect for use in dark or poorly lit areas. Cat 1008170-7 88 Key $69 Cat 1008171-7 105 Key $79 Receive and capture high quality free to air digital TV signals with this DVB-T PCI card. Cat 3564-7 $239 These manual USB switches allow the sharing of a USB device. Compatible with PC and MAC, USB 1.1 and 2.0 Cat 12060-7 Two PC's $49 Cat 12059-7 Four PC's $79 Suited for security applications this RFID controller features secure access via EPROM Eraser RFID tag or Wireless PC Lock PIN code or Combining good performance and low cost, this eraser Automatically locks/unlocks a both. Can be PC when the receiver is within accommodates up to attached to a 12 devices. a 2M radius of the PC. PC for access logging. Cat 3104-7 $199 Cat 8545-7 $79 Cat 1008143-7 $549 Infrared Mini Keyboard A wireless 88 key mini keyboard with pointing device. USB connection and black in colour. Cat 9238-7 $184 Find PC Problems Fast! Magnetic Card Reader This PCI card displays the POST status of a PC on its LED display. Cat 3422-7 $98 Models available to connect via keyboard wedge, serial or USB ports. Cat 8203-7 $259 Wireless LAN Equipment! We’ve got the lot - antennas, cards, pigtails, converters, cables! MicroGram Computers Ph: (02) 4389 8444 FreeFax: 1800 625 777 Vamtest Pty Ltd trading as MicroGram Computers ABN 60 003 062 100, info<at>mgram.com.au 1/14 Bon Mace Close, Berkeley Vale NSW 2261 All prices subject to change without notice. For current pricing visit our website. Pictures are indicative only. See all these products & more on our website...www.mgram.com.au M 2005 3 siliconchip.com.au ay SHORE AD/MGRM0505 Dealer inquiries welcome MAILBAG Definition of IHF Burst Peak Output (Music Power) Can someone please define the term “IHF Burst Peak Output (Music Power) as quoted in the TwinTen (February 2005) project. I was under the impression that peak music power specifications were worse than useless and as such have little place in a good technical journal. This impression was further reinforced by the Publishers Letter in the January 2005 edition which to quote, stated “ ....in fact, if a piece of audio or home theatre equipment makes any reference to “PMPO” (peak music power) it is a fair bet that it is junk...” Now I know that there is no reference specifically to PMPO in the TwinTen article, nor is the project junk but please, what is the relevance of IHF Burst Peak Output (Music Power) and how does it differ from PMPO? Malcolm Fowler, Beaumaris, Vic. Comment: rather than being specified as IHF Burst Peak Output, it should have been simply called Music Power. This is measured using the 20 millisecond tone burst method specified for measuring Dynamic Headroom in the American Institute of High Fidelity IHF-A-202: 1978 specification. It effectively measures the audio power that an amplifier can deliver with typical music signals. It is a legitimate measurement and one which gives a good guide to the amount of power that an amplifier can deliver under typical conditions. PMPO (peak music power output) ratings seldom have any connection to reality and typically far exceed the maximum power consumption of the device, sometimes by as much as 100 times. For example, a device with a maximum power consumption of say, 5W, might have a PMPO rating of 200W! USB-Up power switch a beauty I recently built the USB-Up powerup kit and fitted it to a 4-outlet powerboard, a $2.50 special. This unit is slightly narrower than your PC board 4 Silicon Chip so I shaved a millimetre off each side without any damage to the printed tracks. For safety reasons, the 240VAC cable had to be re-routed to enter from the opposite end. The cable clamp was omitted but drilling a hole just smaller than the 240VAC cable sheath in a spot where the top plastic cover when screwed on acted as a clamp worked fine. It may not meet the modern cable clamp standard but as this device when installed is rarely touched, very secure cable clamping is not an issue. Once I had assembled the PC board and then marked where to cut the base unit of the powerboard for the USB connectors I realised that fixing this PC board via screws was inappropriate as it was held in place very tightly due to the snug fit in the plastic base and the top cover pressing on the tops of the USB connectors. Anyway it worked perfectly when powered up, so thanks again for a beaut kit. J. M. Taylor, Donvale, Vic. Why no 240V door switches? Could someone please explain why simple 240VAC door switches don’t seem to be readily available. Having had our kitchen renovated just recently, I was less than impressed with the ‘state-of-the-art’ solution for an automated pantry light. This consists of an infrared detector switch connected to a 12V halogen light. Yes, the light comes on when you open the door. Having opened the door, however, you are standing there stroking your chin and wondering what you will extract to satisfy your appetite then click - the light promptly goes out again, leaving you in the dark with a rumbling stomach.. Yes, you can extend the period for which the light stays on but this is not a good solution. All told, I regard the infrared switch idea as just plain dumb and vast overkill into the bargain. This eventually prompted me to replace the IR detector with a door switch. It was just a matter of buying one from the local hardware store, or so I thought. No such luck! Door switches seem to be unheard of (except on fridges, cars and house alarms). Eventually I settled on a 240V micro-switch from Jaycar, mounted inside an insulating black plastic box, which I then had to paint white. It works well but it was a lot of fiddling around. Kitchen renovation companies sometimes use micro-switches but they do so with reluctance. I now understand why. Why is it that 240V door switches seem to be unavailable, even from kitchen renovation companies? Is there some law or regulation that prevents manufacturers from coming up with such a device? After all, door switches have many applications - not just kitchen pantries. Rod Ryburn, Fadden, ACT. Large low-speed fan better for PC cooling I recently came across the July 2004 issue and the article about silencing a noisy PC. I have found that a huge fan running slowly is actually far better and cheaper than the cooling options available today. I use a 15-inch 3-speed floor-standing low-profile fan, set to its slowest speed, blowing into the open side of the computer case. Both side panels of the PC case are removed, allowing a nice airflow around all components including the hard-drives, the AGP card and capture card. My machine uses an AMD 3000+ XP CPU, two 120GB 7200RPM harddrives, 8x AGP with 128MB video RAM and Pinnacle AV/DV video capture card. I have HDD TEMPERATURE installed and without the floor-standing fan, the normal operating temperature of the HDDs is approximately 42°C with an ambient temperature siliconchip.com.au of 25°C. With the fan at its slowest speed, the reported temperature drops significantly to around 30°C. Graeme Rixon, Otago, NZ. Comment: the lead picture in that story showed a PC with a huge fan – we included it as a sight gag. But apparently it really is true! So there you go. Raw prawns and persiflage I have two comments: (1) page 66 of the January 2005 issue states that “..twenty or thirty bucks for a kilo of prawns..”. By my reckoning that is extremely CHEAP, unless they are very small in which case they could be mini shrimps. After all, a kilo of prawns (or other things like apples etc) means you should have 1000 of them! So 1000 (typical sized) prawns for the $20 or $30 would be a real bargain! (2)Your articles use the (incorrect) term ‘voltage’ for the (correct but wordy) term ‘electrical potential difference’. For consistency, why not use terms like nanofaradage for capacitance, ohmage for resistance etc? Unfortunately, this is also found in too many publications, classes, lectures and often leads to (at least) students not properly understanding the important (electric) concepts. Any comments? However, the magazine is great. D. Sidors, Port Vila, Vanuatu. Comments: (1) A kilo of raspberries. (2) How can you take issue with a term like voltage? We might have taken umbrage at the suggestion, from an insular personage, that we were involved in incorrect verbiage, then we realised you wished to engage in mere persiflage. To persist with this badinage would give you the opportunity to further disparage. Canal better than desalination I am disappointed with Leo Simpson’s March editorial concerning desalination. He quotes just a handful of figures and supports the “no-brain” technology solution. I wonder how siliconchip.com.au many people have downloaded the Tenix canal brochure? It’s not difficult to make some calculations from the rather minimal data in the proposal. Manning’s formula suggests that a grade of one metre per 100km would provide the flow required. Thus the total head required is just 40m. With fairly efficient axial pumps the power (not “energy”) required is around 5MW, compared to the 25MW the desalination plant will require. This calculation though still fails to come to grips with the real problem. Perth will use all the water that a government is prepared to lavish on it. At the same time Water Corporation pollutes the sea with many gigalitres per year of fresh secondary-treated exsewage water instead of recycling it. The horticultural industry still closely surrounds the city and uses a very significant amount of water that could be redirected to hungry lawns. Leo suggests raising water pricing. While that would increase revenue to buy a bigger desalination plant it is unlikely to reduce suburban water consumption, though it would force some horticulture out of town. The real problem is that we live in a society where the easiest solutions to implement are the buy-more-technology ones, like trucks over trains, that unfortunately cost us foreign exchange and use the most fossil fuels. These solutions are always easier to promote when we avoid looking at the whole set of relevant facts. Kevin Shackleton, via email. Comment: We think you will find that even the most slowly flowing rivers have substantially more fall than 1m in 100km and even then, most slow rivers are very wide to give a large flow - just how wide is this proposed canal going to be? We have more regard for the figures on the Water Corporation website. In any case, it does not now appear that the canal will ever be built. All Australian cities can do much more to promote water conservation and re-use. True & reactive power explained With reference to the letter entitled “Confusion about instantaneous power” (March 2005), I believe it is Atmel’s AVR, from JED in Australia JED has designed a range of single board computers and modules as a way of using the AVR without SMT board design The AVR570 module (above) is a way of using an ATmega128 CPU on a user base board without having to lay out the intricate, surface-mounted surrounds of the CPU, and then having to manufacture your board on an SMT robot line. Instead you simply layout a square for four 0.1” spaced socket strips and plug in our pre-tested module. The module has the crystal, resetter, AVR-ISP programming header (and an optional JTAG ICE pad), as well as programming signal switching. For a little extra, we load a DS1305 RTC, crystal and Li battery underneath, which uses SPI and port G. See JED’s www site for a datasheet. AVR573 Single Board Computer This board uses the AVR570 module and adds 20 An./Dig. inputs, 12 FET outs, LCD/ Kbd, 2xRS232, 1xRS485, 1-Wire, power reg. etc. See www.jedmicro.com.au/avr.htm $330 PC-PROM Programmer This programmer plugs into a PC printer port and reads, writes and edits any 28 or 32-pin PROM. Comes with plug-pack, cable and software. Also available is a multi-PROM UV eraser with timer, and a 32/32 PLCC converter. JED Microprocessors Pty Ltd 173 Boronia Rd, Boronia, Victoria, 3155 Ph. 03 9762 3588, Fax 03 9762 5499 www.jedmicro.com.au May 2005 5 Mailbag: continued timely to clarify the difference between “True” and “Reactive” power. All resistive loads draw current that is in phase with the applied voltage, resulting in consumption of true power, measured in watts. The power factor is high, ie, unity. All purely reactive loads (ie, capacitive or inductive) cause the current to be 90 degrees out of phase with the applied voltage so that the resultant power is reactive power, measured in vars (volt-amperes reactive). As a TAFE instructor some years back, I would demonstrate this by connecting a large capacitor across 240VAC with a seriesconnected ammeter in circuit, which read 10 amps. I would then pose the question, “How much power is being consumed by the capacitor?” The answer is that an average of zero watts of true power is being consumed. However, 2400 vars of reactive power exists and the circuit power factor is at minimum, ie, zero. In reality, power is being consumed by the device for a total of half a cycle and produced by the device for the other half, as a result of the stored energy capabilities of inductors and capacitors. Thus the net average true power is zero watts. In your reply, you state that high power factor loads cause serious problems to the distribution system. I presume you mean low power factor loads, as the power companies apply penalties to consumers with low power factors. Terry Ives, Penguin, Tasmania. Audio/video data is brilliant! I always enjoy every issue of SILICON CHIP. It’s full of interesting material. Regarding the Professional Sports Scoreboard in the same issue, I have no use for a scoreboard but the method of data transmission using video/audio modules is brilliant! It is simple but effective and doesn’t require dedicated (and therefore pricey) data modules. I have dabbled a bit with PICs transferring wireless data with limited success. Is there any reason why these video/ audio modules couldn’t be set up to work as a full duplex data link if the transmitters and the receivers were set 6 Silicon Chip to appropriate channels? And what could the maximum data rate be? Finally, the article about the start of Colour TV (March 2005) was particularly interesting. I cut my teeth on cassette tape recorders and progressed to restoring written-off VCRs (when they were worth $1000+) and then onto fixing computer monitors. It was just a hobby but I don’t do that any more as it isn’t worth spending the time! David Vieritz, Mango Hill, Qld. Comment: We don’t see any reason why you couldn’t use two pairs of 2.4GHz AV transmit & receive modules (set on different channels) to provide a duplex data link. However the simple data modulation system Jim Rowe used is fairly limited in terms of its maximum data rate, because of the audio channel bandwidth. It’s only capable of reliable operation up to about 150 bits per second. More on current transformers I respond to the editor’s comments in the March 2005 edition of Silicon Chip on page 6 regarding the letter from David Millist about “Current transformers can be dangerous”. You are right that in normal operation the voltage across the CT (current transformer) primary is very low but that is only true when the secondary winding has a low ohmic load connected. This secondary load is reflected to appear as the primary impedance (modified by the turns ratio). However, if the secondary is open-circuit, then the primary winding impedance by simple ratio would also be infinite. In practice, it is not infinite, as it can only be a large as the primary winding impedance times the current. This impedance is formed from the primary winding inductance and resistance combined (ie, it looks like a choke). So yes, very high voltages do occur with open-circuit secondary circuits of current transformers. A single wire passed through your iron-cored toroid must complete a full turn loop back to the power source (even if it is miles away), otherwise you get no current. A common misconception is that this only forms a half-turn primary but if you do measurements it becomes apparent that it acts as one full turn. Peter Dettmann, Moonee Ponds, Vic. 230V change in name only In the October 2004 Mailbag, John Hunter asked “What ever happen to 230 volts?”. I work in Christchurch, New Zealand, for an Australian pump company. We build submersible bore-hole pumps from German manufactured components supplied directly to us and held in stock in our warehouse. The motor data sheets supplied to us from Germany show “voltage 400 +10% -10%”. Occasionally, we source a motor from our head office in Australia for an urgent job and the motor data sheet that is supplied to Australia from Germany for the motor shows “voltage 415 +7.5% -12.5%”. So yes, I believe the “conversion for Australia” is largely in name only. Why would a country waste its time and money to change over for 15V when most 400V appliances be affected by the difference? I can understand countries in Europe changing when they are using power generated by neighbour countries. New Zealand chose 230V/400V in the 1920s so when Europe settled on 230/400V it was a stroke of good luck for us. Matthew Thomas, Christchurch, NZ. Current transformer clarification Some clarification required in regard to the letter in the March issue from David Millist and your response to it. The device described in the “Current Clamp Adaptor for Multimeters” in the September 2003 issue is not a current transformer in the sense of the devices used in electric power supply systems for measurement and protection purposes. It is more a current transducer. A typical current transformer may consist of a bar primary conductor (ie, one turn) through the centre of a toroid and a number of secondary siliconchip.com.au turns around the toroid, depending on the ratio required for the CT. For example, a 300/5 CT would have 60 turns ideally but more likely 59 turns to compensate for losses. There would be insulation between the primary and the toroid appropriate to the primary voltage level, eg, 11kV. When the CT is operating as intended, the primary amp turns, 300 x 1, approximately equal the secondary amp-turns, 5 x 60, and act in the opposite direction on the core (Lenz’ Law) so that only enough amp-turns to magnetise the core are present. Depending on the quality of the core, this may amount to say 0.5% to 10% of the current and is the reason that the secondary may be reduced to 59 turns, to increase the secondary current for a given primary current. If the secondary was open-circuited, the amp-turns of the primary would still act on the core without the opposing amp-turns of the secondary and the core would be forced into saturation with resulting high voltage across the secondary winding. Because of non linear magnetic effects this voltage may be of the order of 1000 volts on a highly specified protection CT and could be nasty or even fatal on a modest CT. If you ever work in the power supply industry you soon learn that you never open-circuit a CT secondary winding whilst the primary is energised! Alex Brown, Ashburton, Vic Comment: see our comments and editorial on this topic in the April 2005 issue. SC Australian made LED Indoor & Outdoor lights Powered by LUMILEDS D HIGH BRIGHTNESS D LONG LIFE D ENERGY EFFICIENT This range of interior downlights and outdoor weatherproof light fittings is manufactured in Australia using the latest Lumileds “superbright” LED technology and are ideally suited for use in Marine, Caravans and Mobile Homes that need to be power efficient, but are equally suitable for use in domestic lighting applications. For outdoor use we manufacture a series of weatherproof light fittings using the same “superbright” LED technology. A range of 1Watt, 3Watt and 5Watt Switchmode Power Supplies are available to drive these series of Luxeon LED based light fittings. Weatherproof – Outdoor types This series is weatherproof and can be fully submerged for pond or garden light applications. OPLLBR NEW! 50mm Lenses Accommodates 3x Luxeon LEDs Suited to fit the standard 50mm dichroic halogen lamp holder. OPLLBL OPLLBL Black powder coated Solid brass Indoor - Ceiling mount types OPLLFT3HNB - Narrow reflector OPLLFT3HMB - Medium reflector OPLLFT3HWB - Wide angle reflector (Picture is for illustration purpose only. Lenses not supplied with heat sink or LEDs ) These are all Gimballed - Ceiling mount light fittings and require 57mm cut-out OPLLGW White powder coated OPLLGC Brushed Gold Visit us at: www.prime-electronics.com.au PRIME ELECTRONICS siliconchip.com.au Fixed - Ceiling mount - 51mm cut-out OPLLGG Brushed S/Steel OPLLFG Gold / Chrome Email us: sales<at>prime-electronics.com.au BRISBANE SHOWROOM 22 Campbell Street Bowen Hills QLD 4006 Telephone: (07) 3252 3762 Facsimile: (07) 3252 5778 SOUTHPORT SHOWROOM 11 Brickworks Cntr, Warehouse Rd Southport QLD 4215 Telephone: (07) 5531 2599 Facsimile: (07) 5571 0543 SYDNEY 185 Parramatta Road Homebush NSW 2140 Telephone: (02) 9704 9000 Facsimile: (02) 9746 1197 May 2005 7 KNOCKIN T I TA N ’ S 8 Silicon Chip siliconchip.com.au A seven-year space mission came to a rousing conclusion in mid-January this year when a spacecraft named Huygens made a soft landing on the moon. So what’s unusual about that? Things like that happen all the time. But this mission was rather special. The moon in question was Titan, which belongs to Saturn, not Earth. by Tom Moffat H NG ON DOOR Courtesy NASA/JPL siliconchip.com.au uygens arrived on Titan with a soft plop onto a sea of slushy half-frozen methane. Many scientists believe this unpleasant goo also existed on Earth around the time life was formed, so anything learned from Titan could be applicable to Earth as well. The Huygens probe spent most of its journey attached to a mother ship named Cassini. Cassini wasn’t designed to land on Saturn or Titan. Instead, it went into orbit around Saturn, taking eye-popping pictures of Saturn and its familiar rings. Many of these photos are now on the JPL website for public download. Cassini will continue to fly for the next four years, making 74 orbits of Saturn and 44 fly-bys of Titan, swooping as low as 1200 kilometers. The Cassini-Huygens mission is a powerful example of cooperation between the scientific bodies of several countries. The Jet Propulsion Lab in the USA is responsible for the design, construction, and management of the Cassini orbiter. The European Space Agency was responsible for Huygens and the Italian Space Agency designed the spacecraft antennas. Creating the antennas was no mean feat, given the tasks they were asked to May 2005 9 the film “The Dish”. Because of the rotation of the earth only a few antennas around the world could see Huygens at any one time. In the Hobart installation, two small probe antennas are placed at the focus of the dish, one for left-hand and one for right-hand polarization. Signals from the probes are amplified and then sent to a very stable maser which locks the receiver’s local oscillator to a 5MHz pilot tone. The resulting intermediate frequency feeds an IF-to-video converter which produces baseband signals ready for recording. Back in the early days, a 2-inch videotape recorder was used for this but nowadays the job is done by a special Mark5 computer containing eight hard drives, each of 200 GigaBytes, for a total of 1.6 TeraBytes. During Huygens tracking, Hobart was using two Mark 5’s for a total of 3.2 TeraBytes. The whole multiple hard drive unit can be lifted out and sent elsewhere for data analysis. VLBI The Cassini orbiter and Huygens probe sitting aboard their Titan IV launch vehicle, prior to lift-off on October 15, 1997. The probe flew past both Venus and Jupiter after launch, their gravity giving the spacecraft a “pull”. perform. Huygens collected data as it dropped down toward Titan’s surface and during and after landing. Data signals were then transmitted to the orbiting Cassini, which re-transmitted them to Earth-based receivers. Given Huygens’ small size, it wasn’t exactly a powerhouse of radio energy. The transmitter power was similar to one bicycle headlight. The distance from Titan to Earth is about 1.2 billion kilometres. The path loss would be astronomical. To overcome excessive path loss it is necessary to add some gain somewhere 10 Silicon Chip in the system. In the case of Huygens, bumping up the transmitter power was not an option. So Cassini received, transmitted and added some much needed gain. But the most useful source of gain was the parabolic dish of a radio telescope. Cassini-Huygens graduated from a multi-nation into a world-wide mission when 17 radio telescopes joined in the tracking of Huygens. Australian participants included the University of Tasmania at Hobart (26m dish), Ceduna (30m), Mopra (22m) and Parkes which, at 64m, was the star of Most news coverage about CassiniHuygens concerns the wonderful pictures the spacecraft have been sending back and the data suggesting that Titan may resemble the cradle of life on Earth. But most interesting from a radio astronomy point of view are VLBI studies (Very Long Baseline Interferometry). This technology allows extremely accurate determination of the position of a radio emission source. A comparison: if someone could organize a table-tennis match on the surface of Earth’s moon, VLBI would allow continuous tracking of the position of the ball as it bounces back and forth between the players. VBLI requires several radio telescopes with a few common features. First, they must be widely separated (the Very Long Baseline part) and their clocks must be synchronised to within the accuracy of a maser oscillator. The output of each radiotelescope receiver must be sent to a correlator. This technique assumes that a radio source is being observed by several widely separated radiotelescopes. Because of their different viewpoints, each sees the object within a background of noise. Somewhere in there is the desired signal. Throw in another radiotelescope, siliconchip.com.au While cruising around Saturn in early October 2004, Cassini captured a series of images that have been composed into the largest, most detailed, global natural color view of Saturn and its rings ever made. and another, widely separated, and each will see what looks like noise. But one spike will appear in the same position from all the telescopes. So radio energy at one common place will keep building upon itself, and eventually, there is a correlated, real signal. The Macquarie Dictionary says: “Correlation = a mutual relation of two or more things”. You won’t find a correlator at every radio telescope site. The correlator used for Huygens lives in Holland, under the watchful eye of JIVE, the Joint Institute for VLBI in Europe. It’s a dedicated 60 TeraOps supercomputer spread over several equipment racks. So you can’t just pick up the correlator and take it to a raw data source. You must bring the data to the correlator. That’s what all those removable hard drive packs are for. The JIVE correlator can process data from up to sixteen radiotelescopes at up to 512 megasamples/second per station. Now they accept that the dish over there on the horizon is in fact a worldclass research instrument. Being asked to participate in Cassini-Huygens has brought it even more prestige. So it was that upon the night of January 14, 2005, radio telescope staff marched through the door carrying three large pizzas. It is traditional, at least within the space program, that the workers must be properly fuelled, just like the rockets, before undertaking a large and complex operation. It appears that radio astronomy is similarly affected. After one final cup of coffee, the staff moved into the radio telescope control room. Leading the operation was Brett Reid, the station manager, Jamie McCallum, a PHD student, and Eric Baynes, technical officer. They went through a formal checklist, then did it again and again. Saturn wasn’t to come over the horizon until several hours later and nobody wanted to waste any of that extra time. Touch this, look at that – call it out – Check! . . . just like the captain of a jumbo jet doing his pre-flight. The operation was carefully scheduled: on Christmas day last year, Huygens was freed from its mother ship Cassini. That night, at 1013 UTC, Huygens would enter Titan’s atmosphere. At 1018 a parachute would pop out, hopefully slowing Huygens to some reasonable speed. A minute later the S-band radio link would begin transmitting. The Hobart operation The Hobart dish and the electronics to drive it were donated to the University of Tasmania by NASA about 20 years ago. It was rescued from the junkyard, having been deemed “surplus to requirements”. The dish was re-erected upon a small hill called Mt. Pleasant, from which it could be seen for many kilometres in every direction. Residents of peaceful towns such as Richmond and Cambridge were concerned that they would be exposed to high power radiation. It took a lot of PR work to convince the populace that the dish was for receiving only – it had no transmit capability at all. siliconchip.com.au The recorded data from many widely-separated radio telescopes are correlated to produce the VLBI image. Brent Carlson, National Research Council of Canada. May 2005 11 The University of Tasmania’s “hand-me-down” 26m Mt Pleasant radiotelescope was one of many stations around the world used to receive the unbelievably weak radio signals from the Cassini/Huygens probe. The object of this part of the operation was to measure the wind speed in Titan’s atmosphere using VLBI. Speeds over 400km/h were expected. Our local encounter with Huygens couldn’t occur until Saturn and its attending moons, rings, and orbiting spacecraft came over the horizon. With the dish’s elevation angle set to the contour limit of about 4°, we lay in wait. At 1019, Huygens’ transmitter switched on, cranking out 3.5W, just before Saturn made its appearance from Hobart. It’s not all head scratching – though there is a lot of that! Here Eric, Brett, and Jamie again go through the checklist. 12 Silicon Chip The hard drive data recorder had already been running for several minutes, having first disgraced itself by crashing while we were all outside admiring Saturn, slowly rising in the Tasmanian sky. By the time the signal reached Earth it was so weak that most radio astronomers felt it would be impossible to detect without the use of VLBI. And there would be no VLBI data until all the removable hard-drive packs had made their journey to JIVE’s correlator in Holland. This, of course, results in a challenge irresistible to radio astronomers: Try to resolve the S-band signal on your own. No VLBI, no help from Cassini. Who would be first? We go into a routine monitoring mode. Is the recorder playing up again? No, looks OK. The right lights are flashing. Eric rolls out a cart-mounted spectrum analyzer and patches it into the system. Its screen is showing lots of green “grass” (random noise). Then, oh-so-slowly, the grass develops a gentle hill. We stare at it until someone says “I think there’s something there”. The hump seems to breathe up and down, like the chest of someone sleeping. With some use of imagination, it is starting to look like an indistinct something or other centred right on Huygens transmit frequency. According to the experts, this shouldn’t be happening. Eric starts tweaking the spectrum analyzer’s gain and bandwidth, and the hump gets bigger. Then it deflates again, like letting the air out of a football. Brett comparing notes with other stations. siliconchip.com.au This is frustrating, and thrilling, all at the same time. Is it or is it not a signal from a billion kilometres away? It’s up again, then it fades away. All station personnel are staring at the screen, willing the signal to build up. Brett decides it’s time to compare notes with other radiotelescopes. Ceduna, Hobart’s sister station, has been off the air with a power failure. Between that and the Hobart computer crash, it looks like the gremlins are intent on spending the evening with us. The mystery continues for several hours as the signal builds up, disappears and builds up again. We phone more Australian radiotelescopes: Can you see anything on S-band? No, can you? It appears we’ve got it on our own, the first and only radiotelescope in the world to detect signals from Huygens. Again, tradition within the space program suggests that, whenever a significant success occurs, control room personnel should whoop and holler and jump around giving high-fives. And so it was with Huygens and its dinky little radio transmitter, heard first in faraway Tasmania. Congratulations all around. It wasn’t long before the European Space Agency mission control got wind of our “success” and Project Manager Leonid Gurvits phoned Hobart for more details. The ESA were in the middle of a press conference for the world-wide media. Are we SURE we’re hearing Huygens? Do we claim to be first? What if we’re not? So we say we’ll check further before making a formal claim. Artist’s impression of the final moments in Huygen’s descent from the Cassini “mothership”. Courtesy NASA/JPL. At 1231 GMT, it was expected that Huygens would land or impact on Titan, depending on the severity of its arrival. And sure enough, right on time, the S-band signal disappears rather suddenly. That’s it, Huygens has suffered a mighty prang, long live Huygens. Then comes a message from Parkes: Are you guys still tracking? It’s really nice and strong here now. . . Oh-oh. That couldn’t be right. . . unless we’ve done something wrong . . . Huygens is supposed to be dead! If it wasn’t Huygens, what was it? At time of writing, nothing was proved one way or the other. There is strong suspicion of an interfering Eric trying to coax a signal from the spectrum analyzer. . . siliconchip.com.au birdie, after a weak carrier on 5MHz revealed itself. This is the maser timing signal running all around the station. But, why did the S-band signal keep fading in an out, with the 5MHz signal remaining steady? Investigations are continuing. . . And for what it’s worth, the honour of being first to hear Huygens went to the Greenbank radiotelescope in the SC USA. Well done! Want to know more about Cassini and Huygens? Visit http://saturn.jpl.nasa.gov – or simply Google “Cassini probe” and you’ll find a treasure trove of information, pictures, video and more links . . . “I think there’s something there”. Is it from Huygens? May 2005 13 GETTING INTO Last time we looked at wireless networking (January 2001), the term “Wi-Fi” didn’t even rate a mention. Things have moved on just a tad in that four-and-a-bit years! I n the past few years, there have been three major movements in wireless networking. One is speed – it’s now much faster; the second is availability – now much more equipment is available; the third is price – Wi-Fi equipment is now much cheaper. A lot of the equipment has also become smaller and the software to drive it has become more user-friendly. Before we go any further, let’s try to remove some of the confusion about the terms used for wireless networking. Wi-Fi and 802.11 Wi-Fi, which is an abbreviation of Wireless Fidelity (itself a pretty meaningless term!), is actually a registered trademark of the Wi-Fi Alliance, an organisation set up to ensure technical standards are maintainted. Strictly speaking, Wi-Fi should only be applied to equipment whose manufacturer is a member of the alliance. But rightly or wrongly, like so many computer and technical terms, Wi-Fi has already entered our language as a generic name in its own right. The Wi-Fi Alliance regulates the use of the Wi-Fi trademark, only allowing manufacturers whose equipment passes their rather stringent suite of tests (and who pay big $!) to be certified and use the name/bear the mark. While that control has been relatively successful in maintaining compatibility (they have about 200 member companies worldwide), there are now countless manufacturers who don’t bother joining the Wi-Fi Alliance but nevertheless produce (usually!) compatible equipment. To be compatible, the equipment has to comply with the standard of yet another organisation, the IEEE (Institute of Electrical and Electronics Engineers). The IEEE has many working committees. One of these is the 802 Committee, which deals with computer networks. A sub-group, the 802.11 Working Group, handles the specifications of Wireless Local Area Networks. Various Task Groups within the Working Group handle specific types of Wireless LANs and assign their group code, or letter, to the standards they develop. Thus there is an 802.11a task group, an 802.11b task group and so on (in fact currently there are a, b, c, d, e, f, g, h, i, j, k, m & n groups and possibly more). We’re really only concerned with the 802.11a, b and g standards here. Speed The first 802.11 standard (in 1997) was at the time con14 Silicon Chip sidered fast for wireless – 2Mb/s – but it was agonisingly slow compared to the hard-wired networks of even then. Moreover, it had significant technical problems, not the least being it allowed two incompatible spread spectrum standards (frequency hopping spread spectrum, FHSS, and direct sequence spread spectrum, DSSS) at the same time. So some 802.11 equipment could not talk to other 802.11 equipment. By 1999, the 802.11b standard was in place. It was faster but more importantly, discarded FHSS. Swww.dailo from then on, all equipment was at least theoretically compatible. As you can see, the 802.11b standard has been around for more than five years. 802.11g, introduced in 2003, is now rapidly overtaking 802.11b, mainly due to its much faster speed or throughput. Apart from speed, “g” has other advantages over “b”; for example, it is more efficient in handling reflected (multipath) signals. You will see various claims on speed for the two systems but these must be qualified or you may not be comparing apples with apples (no Mac pun intended). 802.11b is specified as having an 11Mb/s throughput or “raw speed”. For many reasons, mostly due to the way data is packeted and transmitted, the real throughput is usually less than half this, coming in at about 5Mb/s. On the other hand, 802.11g is rated at 54Mb/s but the real throughput is again less than half – around 20Mb/s. But that fourfold increase is certainly worthwhile. Both the 802.11b and 802.11g standards use the same frequency band, 2.4GHz. It was originally chosen because in the US it was an unlicenced “garbage” band (similar in some ways to the 27MHz band) therefore no licence fees would be required. The use of that frequency has proved rather unfortunate, because it is shared with a huge number of devices, from toys to cordless phones to microwave ovens. Therefore, wireless networks can, and often do, suffer interference (or cause it). One advantage, though, of 802.11b and g being on the same band is that 802.11g is backward-compatible with 802.11b; that is, a “g” device can talk to a “b” device and vice versa, albeit at the slower speed of the “b” system. “b” and “g” equipment operates on 11 channels (individual frequencies) between 2.4000GHz and 2.4835GHz. “g” equipment is generally more expensive than “b” – but we are not talking sheep stations. We’ll look at costs siliconchip.com.au ® A FEW YEARS ON... Part 1 – by Ross Tester a little later. 802.11a – an orphan? Despite its earlier alphabetical suffix, 802.11a effectively came about after 802.11b (in fact, the two standards were released simultaneously but the technology to support 802.11b came about faster). 802.11a seemed like a good idea at the time; a new standard operating on a higher frequency (5GHz, far from the madding crowd), with higher speed (54Mb/s raw speed or 25Mb/s real speed). Unfortunately, perhaps like the Beta vs VHS battle of last century, the best system doesn’t always win, due mainly to the inertia and marketing of the inferior system. It wasn’t helped when Apple’s CEO Steve Jobs said that “802.11a is doomed to failure”, justifying his company’s decision to base its AirPort Extreme Wi-Fi on 802.11g. That’s not to say 802.11a is dead in the water – far from it. It still has many proponents and users and prices have fallen significantly – but compared to 802.11b/g its use is miniscule. Maybe, in time, it will emerge a winner but at the moment, we suggest you stick with 802.11g (or b if you must!). There are systems which offer automatic dual band (a and b) and even tri band (a, b and g) operation (depending which one is in the area) but they are usually significantly more expensive. Long range . . . or maybe not! You will often see ranges quoted for Wi-Fi (yes, we’re using the generic) of “up to 300m”. Note that phrase “up to”. By definition, that means somewhere between zero and 300m but our experience is it’s much more likely to be closer to the former than the latter. If you expect to be able to plug in a Wi-Fi card, dongle, or stick into your PC or notebook and expect to be able to access another computer anything like 300m away, in Wi-Fi in the home means no messy cables to run and (theoretically!) you can use your notebook computer wherever you want. As we explain, it’s not always quite that easy – but worthwhile, nevertheless. (Photo courtesy of the Wi-Fi Alliance). siliconchip.com.au May 2005 15 Airports were very early adopters of Wi-Fi – especially handy since 9-11 when you have to book in for international flights 2-3 hours early. In some (limited!) airports, especially in the USA, Wi-Fi access is even provided free by altruistic managements. (Photo courtesy of the Wi-Fi Alliance). those immortal words of Daryl Kerrigan in “The Castle”. . . you’re dreamin! To achieve that sort of range, you’d definitely not want any walls in the way and you’d generally need to use some form of external antenna, probably with some gain (ie, directional). With much of today’s smaller Wi-Fi equipment (particularly for notebooks) the latter is not practical, as antennas are usually built in. However, our Kiwi colleague Stan Swan did describe fitting parabolic antennas to USB Wi-Fi sticks in his “WiFry” article in the September 2004 SILICON CHIP. So what’s the range? As they come out of the box, the typical range of most Wi-Fi devices is dramatically less than 300m – our experience for domestic installations (ie, with typical walls in the way!) is that 10m is about maximum on a good day with a tailwind! An example: my next-door neighbour and I share a broadband cable connection, linked via Wi-Fi. Our houses are side-by-side and his wireless access point is on a wall closest to my boundary. But there are very few places in my home which allow connection – any which do are on his side of my house. So we are talking less than 5m. Even he has problems accessing the system from many places in his home. He’s gone to the trouble of a higher spec (better performing) access point, higher gain antennas and so on. But the improvements were marginal at best. Oh, just in case you were wondering: yes it is perfectly legal to share a broadband connection with your neighbour. Messrs. Telstra, Optus and Co might not like it too much but sharing broadband (ADSL or cable) with a neighbour, via wireless, is a great way to not only keep the cost down but 16 Silicon Chip get a faster and higher usage connection into the bargain! Incidentally, we’re no lawyers but our reading of the relevant legislation suggests that it would be illegal to share a broadband connection with your next door neighbour via a wired network because the cable would cross your property boundary. With wireless, there’s no cable, so you don’t transgress legislation! We might be tempted to have a closer look at explaining how to do this in a future issue – but it’s not exactly rocket science! Wireless networking basics Before we go too much further, we should point out that we’re concentrating here on “PCs”; that is Intel/AMD etc machines running Windows, because they are, far and away, the most common/popular computers in both the home and the workplace. That’s not ignoring the Mac family – Apple has supported Wi-Fi for a long time with its AirPort and AirPort Extreme technology, to the extent where going wireless with a Mac is often easier than with a PC. (Yeah, go on Mac fans. So is everything else . . .) Having said that, perhaps Win fans need more handholding so be quiet, you Mac lot! (Why does a Mac mouse have only one button? ’Cos Mac users can’t cope with two . . .). At the most simple level, to connect computers together in a wireless network all you need is a wireless network adaptor in each computer to be wirelessly networked. We’ll look at various types of adaptors shortly. Wireless adaptor hardware When we covered this area back in 2001 there was very limited choice. The PC-slot cards we described were then quoted at around $490(!) (in 2001 they were known as siliconchip.com.au Setting up a business meeting with wireless networked laptops is easy – a simple ad-hoc system will do fine. All anyone joining the meeting needs is the WEP or WAP code and their computer basically does the rest. (Photo courtesy of the Wi-Fi Alliance). PCMCIA cards, which earned them the name of People Can’t Memorise Computer Industry Acronyms). While PCI cards are still available for desktop PCs – in fact, now very commonly so and really cheap, like anywhere between $10 and $50 – you have a choice of a range of other adaptor hardware, suitable for either desktop or notebook. That assumes, of course, that your notebook doesn’t have wireless inbuilt: all but the lowest end of notebooks these days now come with wireless as standard. But if yours doesn’t (like my IBM R40e!) you can “go wireless” via the aforementioned PC card, a USB “stick” which looks just like flash memory, or an Ethernet connection. PC cards now retail for a tenth (or less) of the 2001 price – you can often pick them up for $20 or less. Wireless USB sticks which, as late as last year, were selling for $100 or more, can now be sourced for much the same price as PC cards. Many notebooks/laptops use a “Mini PCI” card which connects internally and uses aerials which run up the side of the LCD screen, again internally. Some manufacturers include these aerials even if they don’t include the card (to save money) so a Mini PCI wireless upgrade is often a possibility. One big advantage (apart from being completely internal) is that the Mini PCI card usually consumes less power than other cards, important in a battery-operated computer. Another advantage is that the antennas usually (but not always) offer performance advantages over the tiny antennas inside USB sticks or PC cards. The one piece of wireless hardware we haven’t mentioned, although available, is an Ethernet port adaptor. This is an option for a desk-bound notebook or laptop but hardly the type of thing you’d go walking around town with – apart from the fact that battery operation isn’t ususiliconchip.com.au ally offered, it sort of takes away the portability advantage of a laptop/notebook! What about Bluetooth? Bluetooth, though certainly a wireless device, doesn’t really fit into this discussion because it is incompatible with the 802.11 standard (you may note that it is called neither Wi-Fi nor 802.11). In fact, Bluetooth’s incompatibility often causes interference problems for close-by Wi-Fi equipment, as it too occupies part of the 2.4GHz band. While its speed is only 1Mbps (or 700kHz true speed), significantly slower than even 802.11b, it doesn’t have the Ethernet-like overhead of 802.11b so is not quite as “bad” as those figures might suggest. It’s also much lower in range, with about 10m being the maximum you can expect. Bluetooth can be, and is, used for “ad hoc” style networking but is much more suitable for connecting other peripherals (video/still cameras, for example) into the computer system. And WiMax? We mention this here only because we have featured it in SILICON CHIP recently, although not by that name. You may recall our article on the “Unwired” wireless broadband system in November 2004. Unwired is an example of WiMax (and yes, it also has its own IEEE 802 working group – in this case 802.16/802.16a). WiMax is also an acronym – Wireless Interoperability for Microwave Access. It is not a short-range system as in Wi-Fi, it’s intended for relatively longer distance internet access via microwave (radio signals above 3GHz). For more information, refer to the November 2004 article (back issues available for $8.80 inc p&p). May 2005 17 A typical ad-hoc wireless network. No computer (or, as you can see, other devices such as PDAs), are any more “important” than any other. The computers simply talk to each other on demand. The advantage of an ad-hoc system is that it is very simple to set up and no extra hardware is required. But you can’t connect to another network nor to the internet using an ad-hoc network. NOTEBOOK WITH INTERNAL WIRELESS PC CARD PC WITH WIRELESS PCI ADAPTER NOTEBOOK WITH PLUG-IN WIRELESS PC CARD (PCMCIA) Add-in cards We’ve shown a selection of wireless hardware from a couple of well-known sources – Jaycar Electronics and Dick Smith Electronics (New Zealand). Most of these are 802.11g specification and cover both USB and PC card types. In all cases, you will note they have indicator LEDs which show both connection and wireless transmission. Again in all cases, drivers must be loaded before they will operate correctly – and we found it best to use the manufacturer’s software. All the adaptors shown below have inbuilt antennas (one can be varied in direction) so cannot be used with external (gain) antennas. However, some PC card adaptors can connect to pigtails which in turn can be used with external antennas. None of this equipment carries the “Wi-Fi” logo but all worked perfectly with other equipment which does. We’ve also shown a USB Bluetooth adaptor in this photo PDA WITH WIRELESS DESKTOP PC WITH WIRELESS PCI ADAPTER OR USB WIRELESS STICK, ETC so you can see the difference (and the similarities!). It’s significantly smaller than even the smallest USB stick shown here and this is normally the case.. Connecting your computers The first thing you need to do is decide which type of connection you want to make – and that depends on what you want to do. There are basically two wireless network systems – ad hoc and infrastructure. If you only want to be able to communicate between a couple (or a few) computers, say to transfer files between them, or use a printer connected to one computer on the network while at another computer, ad hoc is the way to go. It is relatively simple. However, if like most people you want to be able to connect your computers via wireless through another computer to the internet or even another network, you’ll need an A selection of low-cost wireless networking equipment. Far left are two 802.11b USB “sticks” with an 802.11g USB adaptor alongside (all from Dick Smith Electronics NZ – DSE Australia do not appear to have equivalent products but DSE NZ will mail order back to Australia – see www.dse.co.nz). Far right is a PC card 802.11g adaptor; alongside that is an 802.11g USB stick. At front centre, for comparison, is a USB Bluetooth adaptor (last three products from Jaycar Electronics – www.jaycar.com.au). 18 Silicon Chip siliconchip.com.au DESKTOP PC WITH WIRELESS CARD NOTEBOOK WITH WIRELESS USB “STICK” ACCESS POINT NOTEBOOK WITH WIRELESS PC CARD The difference between the ad-hoc wireless network opposite and the basic infrastructure wireless network shown here is obvious: the additional piece of hardware in the middle, called an access point. It is in turn connected to what might once have been regarded as a fileserver, ie, the main computer in the network. It is through this computer and its internal or external modem that connection to the big wide world (also know as the internet) is possible. While we have shown more devices in this diagram than are in the adhoc network, that isn’t necessarily so: in fact, many infrastructure networks will have just the main computer, the access point and a single notebook computer to give that notebook internet access. INTERNET VIA DIALUP, BROADBAND, ETC PC WITH WIRELESS PCI ADAPTER PDA WITH WIRELESS infrastructure setup. Infrastructure is more complicated, as its name suggests, because you need more hardware equipment than just wireless access cards. To some, an ad hoc network is not a “real” network at all, just a means of file sharing. “Real” networks are built on infrastructure. But the ad hoc method is a perfectly viable option, especially for home users not wishing to make it too grandiose. Because it is simpler, we’ll look at ad hoc first. Ad hoc wireless While it is possible to set up an ad hoc network using most versions of Windows, we strongly recommend using at least Windows 2000 and, if possible, Windows XP. The reason is that the latest Windows versions, XP especially, really make life easy when connecting to or building a network – and Wi-Fi networks are no exception. First, you need to install the internal Wi-Fi card (or USB stick or PC card or Ethernet adaptor) in/on your PCs, along with their drivers. In many cases XP will have a suitable driver but it’s usually best to install the one which came with the card because it will have the latest versions and also include any manufacturer’s “niceties”. Remember to power down the PC first if you’re installing an internal card. It’s not absolutely essential to turn off the notebook or laptop for (external) PC cards or USB adaptors but we’d do it anyway and so let Windows find the new siliconchip.com.au “MAIN” PC WITH MODEM hardware when it loads. Also, some hardware is quite specific about which order installation goes – some require the software loaded first then the hardware installed, others the opposite. And some don’t care! If in doubt, follow that age-old (but oft ignored) advice: if all else fails, read the instructions! Once installed and powered up, unless something is really haywire, Windows lets you know it’s found the new hardware, loads the driver and puts the appropriate entry in Network Connections in the Control Panel. From there it is usually just a matter of “follow the bouncing ball” – most software gives you a step-by-step run-through where it finds and identifies the wireless connection and allows you to connect to it. Naturally, this assumes you have already done this in another computer – otherwise there is no wireless connection to find! Some of the wireless network adaptors we have looked at strongly recommend turning off XP’s relatively automatic wireless networking and use theirs. We have usually found it is better to use the adaptor’s software because it either contains more (or later) features than XP or because it allows the card to be set up easier. Conversely, we have found software where, when something doesn’t work, it doesn’t work big time – and the only way to get around the problem is to uninstall and reinstall the system. But overall, setting up an ad-hoc network should be a relatively painless process. The main reason people have May 2005 19 This Wireless PCI card from Jaycar is typical of the cards available these days. It’s 802.11g, 54Mb/s standard and can take an external antenna. Note there is no Wi-Fi logo? problems at this stage is that the distance between computers is too great and it’s actually a lack of wireless signal that causes the problems. For this reason, when we’re setting up any sort of wireless network, if possible we do it with both/all computers in the same room. When the system is up and running, we move them to their usual locations and hopefully everything still works perfectly. Wireless ecurity We’re covering this here (before moving on to infrastructure networks) because it’s likely that once they’ve set up their ad hoc system, some users may not read any further. And wireless security is really, really, really important. Is that enough emphasis? Many computer users imagine that having anti-virus software and a firewall installed will protect them from intrusion. To some degree, they will – but wireless introduces some extra security problems, problems that a firewall will not help. (What? You don’t have anti-virus software or a firewall? I hope you don’t do any Internet financial transactions . . . and remind me not to read any emails you send me! Then again, they won’t get through mine . . .) By default, Windows will connect wireless without security enabled. Big, big mistake, if you value your data (and even more important when you go on to the next step, an infrastructure network with ’net access). The reason for this is that without security, anyone within range can also log into your network and either take a look around, steal data or do some real damage, if they’re feeling malicious – or all of the above. Snooping really is as simple as turning on their computer and searching for your wireless network (which the computer does automatically!). And that snooper doesn’t have to be particularly close – with a high gain antenna such as a dish aimed at you, they can be some distance – perhaps as much as a couple of kilometres – away. WEP and WPA Wireless networking (currently) has two main methods of preventing unauthorised access – WEP, or Wireless Equiva20 Silicon Chip lent Privacy, and WPA, or Wi-Fi Protected Access. WEP, the older system, is somewhat similar to the security encryption used over a wired network; the difference is of course that it’s quite hard for someone to “tap into” your wired network, especially contained inside a building. Wireless, which by and large doesn’t respect walls, makes it that much easier. WPA is much newer and more secure, so of the two, WPA is by far a better choice than WEP but it’s not always available. Worse still, many people don’t even bother to use even WEP because (a) they are lazy, or (b) they haven’t quite got around to enabling it, or (c) they don’t understand it. (WEP is much better than no security at all, protecting from casual snooping but anyone who knows what they are doing can break WEP fairly easily). WPA comes as a patch with Windows XP Service Pack 2 (XP SP2) which, of course, every XP user should have installed. It’s a free downloaded from www.microsoft.com and we would suggest you do it! WPA unfortunately won’t work with all wireless hardware, especially some older types. In some cases this can be overcome by obtaining the latest drivers for your particular hardware (almost invariably, the setup disc or manual will include a manufacturer’s URL so you can download). If for some reason you’re still running XP SP1 or Windows Server 2003 you’ll need to download and run the WPA patch, again from Microsoft. Where WEP relies on you entering (and remembering!) an obscure hexadecimal number, WPA allows you to enter a plain-text password. It then mathematically generates the encryption key from that. If a snooper manages to find out your password (eg, because you’ve written it on the whiteboard next to your computer in plain view of the outside window!) they can still access your network. But they can’t easily decipher the password from your network data, as is possible with WEP. Our advice is to ALWAYS use security – at least WEP. You can use either 64-bit or 128-bit encryption – the latter is more secure but still not unbreakable. But at least it will discourage the casual snooper. If you can, use WPA. Infrastructure mode security The preceding comments about security apply even moreso if you are setting up an infrastructure mode wireless network and accessing the internet. This is of course the main reason for setting up an infrastructure mode network, though you could be doing it to gain access to another network, etc. Therefore, if an intruder manages to get into your wireless network, they will also have access to the ’net and be able to cost you real $$$, especially if they start downloading movies and music, for instance. Or they could use your system to send harmful email, spam and so on, place bogus orders charged to you or run a variety of scams and you would get the blame as the source. So enable that security! Access points/gateways The main obvious difference between ad hoc and infrastructure mode is that you (usually) need another piece of hardware, usually called an access point or wireless gateway, which connects to the computer containing or attached to your modem and thence internet connection. siliconchip.com.au You’ll also see references to these devices in your Wireless travels. Like many things in wireless, devices tend to mirror the devices found in wired networks. In a “star” network (as distinct from a peer-to-peer) there is a central device responsible for handing out data to all of the computers in the network. It’s sort of like a bike wheel, with all the spokes coming back to a central point. That’s the hub – and in networks, there are three basic types. A passive hub does little more than send the data it receives back out again. While simple and cheap, it costs a lot of bandwidth because the passive hub doesn’t know which computer on the network is supposed to get the data – so it sends it to the lot. A switching hub, on the other hand, reads the address on each packet of data and sends it to the correct computer. Therefore it doesn’t cost a lot of bandwidth. A switching hub is often abbreviated to simply a “switch”. An intelligent hub has the smarts of a switching hub but goes one step further by allowing a network administrator a lot more control. Only if you have a large network (eg, in a big organisation), with someone looking after it, would you need one of these devices. Just like wired networks, hubs and switches are found in wireless networks, doing very similar jobs. Bridges are a bit different to hubs and switches. They transfer packets of data from one physical medium to another. That might be two different networks, for example a wired network and a wireless network. They don’t do anything with the data packets except transfer them – they don’t read them to work out the address, for example. While bridges are very commonly available as standalone devices, for our purposes (remember, we’re talking about wireless!) the most common place you’ll find them is actually part of a wireless access point. They then allow the wireless network and a wired (ethernet) network to talk to each other. Routers and gateways We said a moment ago that bridges merely transfer data packets – they don’t read it as such. But there are types of bridges that do and they’re called routers. As their name suggests, they do read the data and determine where it is siliconchip.com.au www.elexol.com www.elexol.com www.elexol.com www.elexol.com www.elexol.com www.elexol.com Hubs, switches and bridges www.elexol.com www.elexol.com www.elexol.com www.elexol.com 2nd Generation Low Cost USB Data I/O Module Need to get data into or out of a USB port? Here’s what you need 24 independently programmable Input/Output pins grouped into 3 ports. Single module high-speed digital Input/Output solution. Up to 128 modules can be connected to a single PC with capabilities of further expansion. Easy to connect by 0.1” pitch headers to suit standard IDC connectors. Integrated Type-B USB connector. On-board unique serial number in EEPROM and custom programmable FLASH microcontroller. Both USB enumeration information & microcontroller can be re-programmed to suit customer needs. Module powered by the USB from the PC. NEW! UPDATED V3 MODEL HAS ON-BOARD LED INDICATION Just some of our range of USB and MP3 modules ... USB MOD1 - USB MOD2 USB MOD3 - USB MOD4 - MP3 MOD4 USB Plug and - USB Plug and USB Plug and USB Plug and -VS1001 chip. Play Serial Development Module. Up to 920k baud (RS232) and 2000k baud (RS422/RS485). www.elexol.com www.elexol.com www.elexol.com www.elexol.com www.elexol.com www.elexol.com Access points usually provide just the single connection and are now becoming quite cheap. When we looked at Access Points in the January 2001 article we quoted a price of $1155.00 – they’re now readily available at sub $100 for a “no frills” model. Wireless gateways provide the same connection but also may have more than one port to enable you to connect to another, usually wired, network. They are also a bit more expensive. The choice, then, is an access point if you merely want to connect your wireless network to the internet, or a wireless gateway if you want to connect to another network and to the ’net. A little while ago we said that an access point is another piece of hardware – but this is not necessarily so. Access points can be entirely software based – but it’s more usual (and often simpler) to go the hardware route. Play Serial Play Parallel 8-Bit Play Parallel 8Converts Development FIFO Bit FIFO clocked serial Module (2nd Development Development data (MP3) to Gen). 1000k baud Module (2nd Module. stereo audio (RS232) and Gen). Up to 8 out. Suitable for Up to 8 Million 3000k baud Million bits bit (1 Megadriving byte) per sec. (RS422 / RS485). (1Megabyte) per headphones.SC second. Visit our web shop <at> www.elexol.com Elexol Pty Ltd Ph: (07) 5574 3988 Fax: (07) 5574 3833 (PO Box 5972, Bundall, Qld 4217) www.elexol.com www.elexol.com www.elexol.com www.elexol.com supposed to go and then send it to that destination. In fact, in some ways you might regard the internet itself as a huge collection of routers, which read data packets and send them on. Of course, there’s a lot more to the ’net than that but it gives you some idea of data routing. Reading then routing data takes time so invariably, routers cost time and bandwidth. It would be unusual for a home or even medium-sized corporate wireless network to need the services of a router. While English and Australian pronunciation of the word “route” might suggest an alternative, invariably (for we hope obvious reasons) we stick with the American pronunciation where routers rhymes with “shouters”, not “shooters”! And now we move onto gateways. What are they? Good question. Probably the best answer is (usually!) a device which combines most, if not all, of the functions above – and perhaps a few more. Gateways can be, or have the functions of, hubs, switches and routers – and may even add additional hardware features such as built-in modems, firewalls and perhaps a DHCP (dynamic host configuration protocol) server and a NAT (network address translation) gateway. If you don’t know whether you need a gateway or not, chances are you don’t! SC What’s in Part 2? We’ll go through each of the steps (and traps for young players) in setting up both an ad-hoc and an infrastructure wireless network. May 2005 21 SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au By Jim Rowe 45-Second Voice Recorder Module Need to record voice messages of up to 45 seconds long and then play them back at the touch of a button or under the control of a PC or microcontroller? Here’s a low-cost, easy-to-build solid state recorder module that’s ideal for this kind of application. W HEN YOU NEED to record voice messages with the highest possible reliability, there’s no substitute for a solid-state voice recorder chip. There are no moving parts at all, so there are no tapes or belts to break, no heads to clog up with gunk, no motors to burn out and no bearings to jam. Instead, there’s just a memory chip to store and replay the message electronically, any number of times. Because it’s solid-state, the message(s) can be played back instantly – there’s no tape to rewind. Small wonder that most telephone answering machines changed over to this kind of recording years ago. 28 Silicon Chip We’ve described solid-state voice recorder projects in the past and they’ve been very popular. However, the special chips they used eventually became hard to get and so these projects eventually fell by the wayside. This situation recently changed for the better again, when Jaycar Electronics managed to find a good source for a new voice recorder IC, the HK828. This made it possible for us to develop a new recorder design, incorporating not only the features that were popular in the earlier designs but a few more based on the requests we’ve received from readers over the years. The new HK828 chip can store single or multiple messages with a total length of between 40 and 60 seconds, depending on the sampling rate and the voice quality you want. In our new recorder module, this chip is teamed up with a low-cost electret microphone to allow easy message recording, plus an LM386 power amplifier IC which allows the recorded messages to be played back through a small speaker. In addition, we’ve made provision for the module to be hooked up to a 600W/600W line isolation transformer for coupling into another system; eg, an alarm system or a private phone line. There’s also a simple interface so that the module’s functions can be controlled via a PC or microcontroller. The new recorder module runs from 6V DC and draws very little current, so it’s quite suitable for operating from either a battery (eg, four AA penlight cells) or from a regulated 6V plugpack supply. By the way, since the HK828 voice recorder chip is only available from Jaycar Electronics in Australia and siliconchip.com.au Fig.1: block diagram of the HK828 voice record/playback IC. The incoming signal from the microphone is amplified and fed through an AGC stage and anti-aliasing filter before being sampled and stored in a 256K EPROM array. New Zealand, kits for the new recorder will only be available from Jaycar and its dealers – see parts list. How it works Because the HK828 chip forms the functional heart of the unit, you need to have a rough idea of what goes on inside this chip in order to understand how the recorder works. Fig.1 shows the chip’s basic architecture. First, the chip includes a high-gain microphone preamp so that it can be driven directly by a low-cost electret microphone insert. An automatic gain control (AGC) stage follows this preamp, to ensure that good quality recordings can be made without any need for manual gain adjustment, despite input signal level variations. The output of the AGC circuit is not connected directly to the chip’s recording circuitry but is instead brought out to the “Aout” pin. This is linked to the “Ain” pin by the user, to record messages from the microphone. This arrangement also allows the chip to be used to record from line level signals in other applications. Since the main part of the HK828 records by sampling the audio signals fed into it via the Ain pin, it needs to pass these signals through a low-pass filter before the sampling. This is done to prevent distortion caused by samsiliconchip.com.au pling aliases, hence the “anti-aliasing” filter between the “Ain” input and the sample and hold circuit block. Now although the audio is sampled inside the HK828, this is done using an analog sample-and-hold system rather than the more common digital sampling system. This is done because it stores the samples in an array of 262,144 (256K) Flash EEPROM analog storage cells, each of which can store any of 256 different voltage levels. This gives the equivalent of 8-bit digital recording. The capacity of the storage array means that the HK828 can store a total of 256K samples. However, the length of the recorded message depends on the sampling rate that’s used. For example, if the sampling rate is 8000 samples per second, 256K samples will correspond to a total message length of just over 32 seconds (262,144/8000). However, if you sample at 4200 samples per second, the 256K samples will give a total message length of just over 62 seconds (262,144/4200). The recording bandwidth or “fidelity” also depends on the sampling rate – in this case, directly rather than inversely. So if you sample at 4200 samples per second, the recording bandwidth will be just over 2kHz, whereas 8000 samples per second gives a bandwidth of just on 4kHz. Choosing the sampling rate is therefore something of a compromise: the lower the sampling rate the longer the recording time but the lower the audio bandwidth. Conversely, the higher the sampling rate the higher the bandwidth but the shorter the recording time. The HK828 chip has an internal sampling rate clock oscillator, as well as an input for an optional external clock. Either clock signal can be fed to the sample and hold circuit via the multiplexer (MUX), to control the sampling. The internal oscillator is particularly easy to use, because its frequency is set simply by varying the value of an external resistor connected between the “OscR” pin and ground. In this recorder, we have selected a 47kW resistor, which sets the sampling rate to about 5800 samples second. This gives a message recording time of about 45 seconds and a bandwidth of about 2.9kHz, for reasonable voice-quality recording. As shown in Fig.1, the recording and playback of samples in the storage array is controlled by analog write and read circuits, along with the message control and message decoding circuits. When a message is being played back, the signals pass through another lowpass filter to remove sampling noise May 2005 29 Fig.2: the complete circuit of the voice recorder uses just two ICs – the HK828 voice record/playback IC (IC1) and an LM386N audio amplifier. Power can come from a regulated 6V plugpack supply or from batteries (4 x 1.5V cells). and are then fed to the inbuilt output amplifier. The rest of the circuitry inside the HK828 chip is used for overall device control and mode switching, etc. Circuit details Fig.2 shows the complete circuit details for the Solid-State Voice Recorder. As shown, signals from the electret mic insert are coupled into the MicIn input (pin 17) of the HK828 via a 100nF capacitor. Another 100nF capacitor is used to tie the preamp’s “MicRef” input (pin 18) to ground, to provide maximum gain. The 4.7mF capacitor and 220kW resistor connected between pin 19 and ground are used to optimise the chip’s AGC attack and decay characteristics for speech. The amplified audio from the mic preamp and AGC circuit appears at pin 21 (Aout) and is then fed to pin 20 (Ain) via another 100nF capacitor. As mentioned previously, the inter30 Silicon Chip nal sampling oscillator frequency is set to 5.8kHz by the 47kW resistor connected to ground from pin 7 (OscR). Manual selection of the HK828’s operating mode (record or playback) is achieved by switch S2, which connects the chip’s RE-bar pin (27) to ground for record mode. When S2 is in the Play position, the RE-bar pin is pulled up to +6V via the 22kW resistor and the base-emitter junction of transistor Q1, which forces the HK828 to operate in playback mode. Note that when S2 is in the Record position, this not only grounds pin 27 of the HK828 but also turns Q1 on. This in turn drives LED2 – the Record Mode indicator – via a 680W currentlimiting resistor. When the unit is switched to Record mode, recording the message you want to save in the chip is very simple – press pushbutton switch S1 and hold it down while you record the message. During recording, LED1 flashes to indicate that the HK828 is operating, while LED2 is turned on continuously. At the end of the recording, you simply release S1. However, if your message is too long for the chip’s memory, it will automatically stop recording when the memory is full. To replay the recorded message, S2 is first switched back to the Play position. Then the manual “rewind” button (S3) is pressed briefly to take the chip’s CE-bar pin (23) to +5.4V, which makes sure the HK828 is reset to the start of its memory. If you then briefly press pushbutton switch S1, the HK828 will replay the message. The replayed audio emerges from pins 14 & 15 of IC1 (ie, from SP+ and SP-). In this circuit, the signal from pin 14 is fed though a 10kW resistor and 10mF coupling capacitor to trimpot VR1, which is used to set the playback volume. The signals are then fed to an LM386N audio amplifier (IC2) which drives the external loudspeaker. siliconchip.com.au This is what the assembled PC board should look like. Note this is a photo of an early prototype before we fitted the power switch. In addition, both output pins of the HK828 are brought out to terminal pins L1 and L2. These can be used to connect the recorder module to the primary winding of a 600W/600W isolating transformer (such as the Jaycar MA-1510 or MA-1512), so that the audio can be fed to other equipment (eg, an alarm system). The remaining part of the circuit provides a simple interface which allows the voice recorder module to be controlled by a PC or a microcontroller. This involves bringing the HK828 control lines out to 10-pin IDC header CON1, so they can be manipulated by an external microcontroller programmed to duplicate the actions of switch S2 and pushbutton switches S1 & S3. Note that when this interface is connected to a microcontroller, switch S2 must be left in the Play position. This is necessary to allow the microcontroller to control the logic level on IC1’s RE-bar pin (pin 27). There’s one final point to note about the HK828 recorder chip and the way we’re using it here. The HK828 can actually be programmed to record in a number of different “message mode” formats, by manipulating the logic levels on pins 9 (M8option), 24 (MSEL1) and 25 (MSEL2). In this circuit, we operate the chip in “tape mode” format, where it can record either a single continuous message or a number of shorter messages in sequence. However, the module’s PC board has been designed to allow you to change the format if you wish, by cutting short tracks and/or fitting pull-up resistors or links. It’s not hard to set the HK828 to siliconchip.com.au record two, four or eight short fixed-length messages, which can be replay-ed in random-access fashion (more on this later). Construction All of the components used in the Voice Recorder module except the speaker and battery mount directly on a PC board coded 01105051. This board measures 107 x 57mm, which Fig.3: follow this parts layout to assemble means that it can be mountthe Voice Recorder. Make sure that all polarised components are correctly ed inside a standard UB3installed and be sure to install S1 & S3 as size utility box. shown – ie, with the “flats” on the switch Fig.3 shows the parts laybodies facing LED1 & LED2. out on the PC board. Start the assembly by fitting the eight PC-board terminal pins, then install the three wire links. to fit them as shown in Fig.3. In parThese links are all relatively long and ticular, note that the 1000mF electrolytic should be run using insulated hookup capacitor mounts on its side, with its wire. leads bent down by 90°. Next, fit the 28-pin DIL socket for Now for the semiconductors. Once IC1, making sure you orientate it with again, these parts are all polarised, so its notched end towards the right. That follow Fig.3 carefully when installing done, fit the 10-pin IDC header, with them. Fit diode D1 first, then transistor its slot side towards the left as shown Q1 and the two LEDs. Finally, fit the in Fig.3. LM386N amplifier (IC2). Don’t plug Once these hardware items are in the HK828 chip into its socket just yet place, fit trimpot VR1 and the resistors. though – that step comes later. Table 1 shows the resistor colour codes Switches S1-S3 can go in next – it’s but it is also a good idea to check them just a matter of pushing them all the using a multimeter as the colours can way down onto the PC board and solsometimes be difficult to read. dering their pins. Note that the “flats” Next come the low value MKT ca- on the bodies of S1 & S3 must face pacitors (100nF and 47nF). These are towards LED1 & LED2. unpolarised so you can fit them either The electret mic is fitted by solway around. dering its two leads to the PC board The tantalum and electrolytic capaci- terminal pins just behind switch S2. tors can go in next. Unlike the MKT Note that the mic is polarised – the types, these are all polarised, so be sure lead which is connected to its metal May 2005 31 VR1 to set the replay volume to an acceptable level. This will depend on the sensitivity of your speaker. If your recorded test message plays back as it should, your Solid State Voice Recorder is working correctly and should now be ready for use. One further point – you’ve possibly noticed the link on the circuit diagram labelled “Beep Mute” and indicated on the PC board overlay diagram as “BM” (just to the right of VR1). This link may be fitted if you don’t like hearing the small “beeps” which the HK828 chip sends out to the speaker to acknowledge the control signals fed to it from switches S1-S3. Fitting the “BM” link grounds pin 11 of IC1 and disables this “beep” function. The completed PC board from the opposite angle. Note the mounting method for the 1000mF electrolytic capacitor (top left). case must be connected to the lefthand terminal pin on the board. Next, solder the battery snap leads and the speaker leads to their respective terminal pins. It doesn’t matter which way around you connect the speaker but take care with the battery leads (ie, connect the red battery lead to the “+” terminal and the black lead to the “-” terminal). Finally, complete the assembly by plugging the HK828 chip into its socket. Make sure that all pins go into the socket and check that the notched end of the IC is to the right. Your Solid State Voice Recorder should now be ready to go. Trying it out To check that your recorder is working correctly, first set trimpot VR1 to mid-position and connect a 6V battery or regulated 6V power supply to the battery lead. That done, press the Rewind button (S3), to make sure that the HK828 has reset its storage array address correctly. Changing message length Next, set switch S2 to the Record position and check that the Record LED (LED2) starts glowing. If it does, press S1 (the Run/Start button) and hold it down while you talk into the electret mic to record your message. As you speak, you’ll notice that the green Run LED (LED1) is flashing. Keep talking until you reach the end of your message, or until LED1 stops flashing (indicating that the recording has stopped, because you reached the limit of the HK828’s memory). Finally, release S1 and that’s it – your message has been recorded. To replay the message, first set S2 over to the Play position and briefly press pushbutton S3 to reset the HK828’s memory address (ie, to “rewind” the unit). Now press pushbutton S1 again but this time only briefly because in Play mode, S1 only triggers the replay operation (ie, it only has to be held down during recording). Your recorded message should now be replayed through the speaker, although you may need to adjust trimpot As mentioned earlier, the message length stored in the HK828 chip’s memory is determined by the sampling rate and this is set by the resistor connected from pin 7 (OscR) to ground. A value of 47kW – as shown in the circuit and overlay diagram – gives a sampling rate of 5800 samples per second, resulting in a message length of 45s and an audio bandwidth of about 2.9kHz. We picked this as a reasonable compromise between message length and recording quality but you are free to experiment with the value of this resistor to try longer/shorter recording times and narrower/wider audio bandwidths. For example, a value of 82kW, will lower the sampling rate to about 4200 samples per second and increase the recording time to 60s. At the same time, the audio bandwidth will drop to about 2kHz, so the replayed message(s) will sound rather muffled. On the other hand, a value of 24kW will increase the sampling rate to about Table 1: Resistor Colour Codes o o o o o o o o o No. 1 2 6 2 2 2 1 1 32 Silicon Chip Value 220kW 47kW 22kW 10kW 1kW 680W 47W 10W 4-Band Code (1%) red red yellow brown yellow violet orange brown red red orange brown brown black orange brown brown black red brown blue grey brown brown yellow violet black brown brown black black brown 5-Band Code (1%) red red black orange brown yellow violet black red brown red red black red brown brown black black red brown brown black black brown brown blue grey black black brown yellow violet black gold brown brown black black gold brown siliconchip.com.au Table 2: follow this table to change the message recording mode – see text. 8000 samples per second and reduce the recording time to 32s. However, the recording quality will improve, as the audio bandwidth will increase to about 4kHz. So experiment by all means and settle on the resistor value you decide gives the best combination of total message length and acceptable audio quality for your application. Changing recording mode If you wire up the module exactly as described, it will operate in “Tape Mode” . We decided to make this the default mode because we believe it’s the most suitable for a majority of applications. However, if you need the module to work in one of the HK828 chip’s alternative “random access fixed length messages” mode, this can be done fairly easily. All you have to do is cut one or both of the short narrow tracks which currently link pins 24 & 25 of the HK828 to ground and fit one or two extra 22kW resistors to pull these pins up to +6V instead. Table 2 shows how to program the HK828 for Random Access mode with either two, four or eight fixed duration messages, as well as the default Tape Mode. As you can see, it’s relatively straightforward. But remember that if you set it for a relatively large number of fixed-length messages, they will each have a relatively short length. So with the sampling rate left at 5800 samples per second, giving a total recording time of 45s, you’ll get two fixed length messages of 22.5s each, or four messages of 11s each, or eight messages of only 5.5s each. Remember too that in any of the Random Access modes, pin 1 (M1-bar) of the HK828 chip no longer becomes the record/replay trigger line for all messages. Instead, S1 becomes the Record/Start Play button only for the first randomly accessed message. You’ll need to connect additional pushbuttons for recording and playing back the remaining messages. siliconchip.com.au For example, if you set pins 24 and 25 for recording two fixed length messages, you’ll need to connect an extra pushbutton switch between pin 2 (M2bar) of the HK828 and ground, to allow the second message to be recorded and played back. This switch can be connected between pins 9 and 2 of the 10-pin IDC header, by the way. If you set pins 24 and 25 for recording four or eight fixed length messages, things get more complicated because you then need an extra pushbutton and 22kW pull-up resistor for each of the additional messages. These extra pushbuttons and pullup resistors need to be connected to pins 3 & 4 of the HK828 for four messages and to pins 3, 4, 5, 6, 8 & 9 for eight messages – although pin 9 won’t need a pull-up resistor, because it already has one. The reason for this extra complexity is that in its random-access modes, the HK828 has a separate record/ replay trigger line for each message. That’s why pin 2 is labelled M2-bar, because it becomes the record/replay trigger input for message 2. When you program the chip for four messages, pin 3 becomes M3-bar (the trigger input for message 3) and pin 4 becomes M4-bar (the trigger input for message 4). And if you program the chip for eight messages, pins 5, 6, 8 & 9 become M5-bar, M6-bar, M7-bar and M8-bar respectively. Expansion possibilities As mentioned earlier, this unit could be used as a voice module for an alarm system. For this and other applications of the Voice Recorder, you’ll probably want to connect it to a PC or microcontroller so that it can be controlled automatically. As shown in Fig.2, all the logic lines needed for controlling the recorder chip are available via the 10-pin IDC header CON1 (pins 6-10), along with a couple of lines which can be monitored to check the HK828’s status (pins 3 & 5). Interfacing the unit is really Par t s Lis t 1 PC board, code 01105051, 57 x 107mm 1 electret mic insert 1 10-pin (5 x 2) IDC header 2 SPST PC-mount pushbutton switches (S1,S3) 2 SPDT mini toggle switch (S2, S4) 1 28-pin 0.6-inch IC socket 8 PC board terminal pins 1 battery snap lead 1 battery holder (4 x AA cells) 1 20kW horizontal trimpot (VR1) Semiconductors 1 HK828 voice record/playback IC (IC1) 1 LM386N power amplifier (IC2) 1 PN200 PNP transistor (Q1) 1 5mm green LED (LED1) 1 5mm red LED (LED2) 1 1N4004 diode (D1) Capacitors 1 1000mF 10V RB electrolytic 1 470mF 10V RB electrolytic 2 220mF 10V RB electrolytic 1 22mF 16V RB electrolytic 1 10mF 16V RB electrolytic 1 4.7mF 35V TAG tantalum 5 100nF MKT polyester (code 104 or 100n) 1 47nF MKT polyester (code 473 or 47n) Resistors (0.25W 1%) 1 220kW 2 1kW 2 47kW 2 680W 6 22kW 1 47W 2 10kW 1 10W Miscellaneous Hook-up wire for PC board links, speaker leads, etc. Where To Buy A Kit This project has been sponsored by Jaycar Electronics and they own the design copyright. A full kit of parts will be available from Jaycar Cat. KC-5412. quite straightforward – just connect these pins to the printer port of a PC (or to the I/O pins of a microcontroller) and then arrange for the software to control the recorder by duplicating the actions of switches S1-S3. Finally, remember to set S2 in the Play position, so that the PC or microcontroller will be able to toggle the SC HK828’s RE-bar line. May 2005 33 Quality Stereo HOONUER PROJECT! Wireless Microphone or Audio Link By Ross Tester Here’s an easy-to-build stereo wireless audio link or microphone that offers long range and is very easy to build, as it’s based on a pre-assembled transmitter module. You can receive it on any FM broadcast band receiver. I count mic differences or if you require are supplied in the kit. These can t’s certainly not the first wireless different levels in each channel. be soldered direct to the PC board to microphone we’ve ever published By the way, the transmitter module make it a fully self-contained project but this one is a little different. is quite capable of operating at line or they can be attached to the board via First of all it’s stereo, providing suprislevel if you want just a line level transsuitable lengths of mini shielded coax ingly good quality sound. mitter (eg, to feed an audio program cable. A third option is to use “proper” Second, it has a really good range. around your home). Sensitivity is microphones – they can be electret or We tested it at well over 50m and it was about 100mV. Oatley Electronics, who dynamic types – but no provision has still performing very well – noise-free, designed the kit, have the transmitter been made for plugging these in. in fact – but at the time we couldn’t module available by itself if that’s what get our receiver any further away. So Construction you’re after. But more on that anon. it’s likely to have even better range You also have the choice of two Start with the smallest components than that. – eight resistors and four capaciThird, it really is simple to build tors, ensuring that the electro– the hard work (the transmitter lytic capacitors are the right way module) is already done for you. around (+ towards edge of PC It’s just a matter of assembling the . board). microphone module, which conHz 5k -1 Hz 20 .. ... ... ...... Audio response: ..... The two electret bias resistors tains the electret mics themselves, ......................... 40dB n: tio ra pa (the 4.7kW resistors closest to the preamp and level controls, and solse l ne an Ch :.................0.1% on edge of the PC board), are only rti dering the transmitter module onto sto Di ic on rm Total Ha 7.2MHz required if electret microphones it, “piggy back” style. 10 76. 10 ... ... ... y:. Output Frequenc are used – they can be left out if Finally, the transmitter module is mS ........................... 50 you use dynamic microphones. crystal-locked, so you won’t have the Pre Emphasis:....... 15V range:................ 3ge lta By the way, keep the resistor drift probles of some earlier wireless vo ly pp su DC .. 30mA <at> 9V ... pigtails when you cut the off – microphones. And just in case you ... ... ... ... ... . :. nt rre Supply Cu you’ll need some of them in a were wondering, that doesn’t mean moment! the output is locked to one particular power supply levels – 3-6V or 7-15V We’ll assume you are going to make frequency – it has a nifty synthesis DC. The latter results in a lower current the module self-contained; ie, the circuit built in to give you the choice drain. The transmitter module also has tiny electret microphone inserts are of seven different frequencies between a “5V out” rail to supply power to the soldered to the PC board. 106.7MHz and 107.7MHz. preamp module. It does matter which way around On-board preset pots adjust the senTwo electret microphone inserts the inserts go – look closely at the sitivity of each channel to take into ac- ns: o Typical Specificati 34 Silicon Chip siliconchip.com.au It’s easy to build, requires very little setup . . . and it’s cheap! In fact, the low price might turn some people off, thinking it’s low quality. Try it – and be pleasantly surprised! two pins and you will see that one of them is connected to the insert body or case. This is the negative or earth pin and goes, in both cases, to the “–” mark on the PC board overlay (towards the middle of the board). If mounting the microphones remotely, ensure that the earth braid of the microphone cable connects to the “–” on the PC board and the negative pin of the microphone inserts. If using other microphones, you will probably want to connect a couple of 3.5mm sockets to the PC board so you can plug the microphones in at will – remember, once again, that polarity matters! And if you want to use the complete kit for line level (100mV or so) inputs, you can increase the 10kW resistors at the op amp inputs to 47kW and leave out the two 4.7kW resistors as above. The tiny pushbutton switch which selects frequency can be soldered in next. The pins are slightly offset so unless you really force it in, it cannot go in the wrong way. The only other passive components to mount are the two 1MW “gain” trimpots, VR1 and VR2. These may +5V 100 µF 4.7k* 100nF 10k LEFT IN 4 4.7k 4.7k 1 IC1a 3 4.7k* FREQUENCY SELECT IC1: M5223 100 µF 760mm INSULATED WIRE +5V OUT 8 2 LEFT CHANNEL IN ANTENNA VR1 1M 10k ANT VHF FM TRANSMITTER MODULE 3-6V IN FREQ SEL 7-15V IN S1 3-6V DC OR 7-15V DC 5 100nF RIGHT CHANNEL IN SC 2005 10k 6 IC1b 7 RIGHT IN GND 0V VR2 1M 10k FM STEREO TRANSMITTER * THESE RESISTORS ONLY NEEDED WHEN ELECTRET MICROPHONES BEING USED CHANGE THESE RESISTORS TO 47k FOR LINE LEVEL INPUTS Fig.1: all you have to build is the preamp. The transmitter is pre-assembled and aligned. Easy! siliconchip.com.au May 2005 35 The transmitter module Based on a Rohm BH1417F chip, the internal workings of which are shown above, the transmitter module was originally manufactured for use in small audio wireless devices fitted into cigarette-lighter plugs in cars, hence the strange board shape. The module also contains a DC-DC converter to supply 5V which we tap into for the microphone/preamp circuit. The front side of the module is shown below (left) approximately same size, while the underside is shown below (right). As mentioned earlier, it is complete and ready to use in its own right – it will accept line level (300mV or more) input (from a CD player, for example) and needs only power and an antenna wire to operate. The module has been typeapproved for acceptance by the US FCC so would also pass the LIPD standards here in Australia. It is not only pre-assembled, it is pre-aligned and ready to rock. The only user setting is the transmitter frequency, which is set by a push-button (so there’s no fiddly tuning!). You have a choice of seven different frequencies 36 Silicon Chip between 106.7MHz and 107.7MHz (so there should be no collisions with local FM radio stations). The default (power up) frequency is 107.7MHz. Each time you push the button, you decrease the frequency 200kHz and the on-board LED flashes once to acknowledge. When you reach the lower limit (106.7MHz) the LED flashes three times. Incidentally, the BH1714F chip is the same as used in the SILICON CHIP Micromitter (mini stereo FM transmitter) published in December 2002. This module essentially does the same job as that project, at a lower cost. In this case, though, the module only offers seven frequencies whereas the Micromitter offered 14 (another seven between 87.7MHz and 88.9MHz). ( A full description of the operation of the BH1417F chip can be found in the December 2002 article. Copies of that magazine or a reprint of the article can be obtained from SILICON CHIP for $8.80 including GST and postage. Like that project, you can use any standard FM broadcast band receiver to pick up the signal from the transmitter. If it’s a stereo FM receiver, it will receive stereo. siliconchip.com.au FREQ SEL 3-6V IN LEFT GAIN G K222 FM TX RIGHT GAIN 100nF ANT +5V OUT PIN 1 VR2 10k 4.7k 4.7k 4.7k GND 7-15V IN IC1 M5223 100 µF + RIGHT CHANNEL MIC G VR1 1 3-6V IN FREQ SEL S1 1M G LEFT CHANNEL 100 µF MIC + 10k 4.7k 4.7k 4.7k 100nF 1M 7-15V IN R L +5V 760mm ANTENNA WIRE Fig.2: the component overlay shows just 16 components and a pre-built module to go onto the PC board. It shouldn’t take more than an hour or so to build. © oatleyelectronics.com Want cheap, really bright LEDs? We have the best value, brightest LEDs available in Australia! Check these out: Luxeon 1, 3 and 5 watt All colours available, with or without attached optics, as low as $10 each Low-cost 1 watt Like the Luxeons, but much lower cost. •Red, amber, green, blue and white: Just $6 each! Lumileds Superflux These are 7.6mm square and can be driven at up to 50mA continuously. •Red and amber: $2 each •Blue, green and cyan: $3 each Asian Superflux Same as above, but much lower cost. •Red and amber: Just 50 cents each! •Blue, green, aqua and white: $1 each. Go to www.ata.org.au or call us on (03)9419 2440. This photo is reproduced significantly larger than life size so you can see exactly where the components go and, where it is important, which way around. The red and black wires at top are for power, the black wire at right is the antenna. be supplied in the kit as horizontal or vertical-mounting types; either can be accommodated on the PC board. Now we come to the final “main” PC board component, the op amp IC. It may have a socket supplied – in which case, solder in the socket. The notch in the end faces away from the microphones. Don’t insert the IC yet. If you don’t have an IC socket, carefully solder the IC itself in – again, with the notch facing away from the microphones. The insulated power supply wires can now be soldered on. The black, or ground wire, is easy; it connects to the +5V OUT PIN 1 R siliconchip.com.au Connecting the transmitter module Before soldering in the transmitter module, an antenna needs to be connected to it. This should be a length of insulated hookup wire cut to exactly 760mm long. FREQ SEL 3-6V IN G 7-15V IN point marked GND on the PC board. The red, or positive, wire, connects to the appropriate position on the PC board for your supply: to the 3-6V point if you have a 3-6V supply or the 7-15V point if you have a 7-15V supply. (Don’t connect more than 6V to the 3-6V supply point!). L Fig.3: this diagram shows the seven connection points between the transmitter module (green, on top) and the main board (grey, underneath). Fig.4: this is how to bend the wire link between pin 1 of the IC and the 18mm main 6mm board +5V 1mm position. If you start with a 765mm length and cut off 5mm of insulation for soldering, you’ll be spot on. There are actually two positions marked “antenna” on the transmitter module. Use the one closest to the LED. Trim any excess wire from under the module. All connections between the two PC boards are made using resistor lead offcuts (commonly known as pigtails). Most are just short lengths (they end up around 4mm or so), soldering directly between the main PC board and the transmitter board above. However, one connection, the +5V connection, does not have any provision on the transmitter board and must be treated differently. Cut a 25mm length of pigtail and bend as shown in the diagram below right (Fig.4). The tiny bend end solders directly onto pin 1 of the IC nearest the antenna lead you just soldered in, as shown in the overlay diagram. This IC is a surface-mount type and therefore the pins are very close May 2005 37 Parts List – Stereo FM Microphone 1 mini transmitter module (Oatley) 1 main PC board, code K222, 67 x 40mm 1 length of insulated mini hookup wire, 765mm long (antenna) 2 lengths hookup wire, red and black, length to suit (power) 1 mini-DIP (8-pin) IC socket 1 mini pushbutton switch, SPST 2 electret microphone inserts (see text) Semiconductors 1 5223 dual op amp (IC1) Capacitors 2 100mF 16V PC electrolytics 2 100nF (0.1mF) polyester Resistors (1/4W, 1%) 6 4.7kW 2 10kW 2 1MW mini trimpots together. You’ll need a fine pointed, well-tinned iron and a good eye (or a magnifying glass). It’s easiest (and safest) to solder the link wire to the outside of pin 1. The other end of this wire goes over the edge of the transmitter board and solders to the +5V point of the main board – but this should be left until the other wires are soldered to their respective points on the transmitter board. Don’t try to cut the wires to short lengths yet – this can be done after soldering. In fact, it’s probably easiest if you use complete resistor lead offcuts – or if you don’t have enough offcuts, at least half length offcuts. It makes holding them (with a pair of fine pliers!) that much easier while soldering if they are longer. Apart from the +5V connection we talked about earlier, there are six connections between the two boards. First, solder these to the transmitter module board in the positions shown in the diagram, with the majority of the lead on the underside of the board. Now pass these six wires AND the end of the +5V connecting wire through their respective holes on the main board so that the two boards end up, say, 2-3mm apart (it’s not critical). In all cases except the +5V wire, the 38 Silicon Chip And finally, a view from the opposite (transmit module) end. You can clearly see that link between pin 1 of the IC and the +5V point on the main board. sets of holes are right above and below one another. Solder all seven wires to the underside of the main PC board, being careful not to unsolder them in the transmitter board above! When you are satisfied that your soldering is OK, carefully cut the six interconnecting wires above the transmitter board and below the main board so that all you are left with is short links between the two. Trim the +5V wire on the underside of the main board. Because the holes in the transmitter board are plated-through, if necessary you should be able to touch-up the soldering on that board, from above, when completed. Testing After giving the kit a complete visual inspection and satisfying yourself it’s all good, insert the op amp IC into its socket on the main board (if you haven’t soldered it in, of course) and wind the two preset pots down to minimum. Connect power and the LED should light. With a suitable FM radio, tune to near the top end of the band – at one point (actually 107.7MHz) you should find that the radio mutes or goes quiet. This is good – it means that you are “on the air”. Now slowly adjust each of the two pots up in turn. Before too long, you should hear any sound made in the room (click your fingers, for example) coming through the radio speakers. If you go too far, you’ll probably find that the sound becomes distorted. And if you go further, you’ll find that it goes into feedback and you’ll get a howl from the speakers – exactly the same as you will hear from any microphone and speaker that are too close together. When you are happy with the level, adjust the two pots so that they are close to equal, unless for some reason you need to have one channel higher than the other. Finally, remember that you can also use this project for an audio link, fed from any line level output. Simply remove the microphones and their associated 4.7kW resistors and increase SC the 10kW resistors to 47kW. Where From, How Much? This project design is copyright (C) Oatley Electronics 2005 and kits are only available from Oatley. The complete kit of parts (everything listed in the parts list including transmitter module) sells for $29.00 inc. GST, plus p&p. (Cat K222). The fully assembled and tested transmitter module only (ie, no main PC board nor components) is available separately from Oatley Electronics for $22.00 inc GST, plus p&p. Oatley Electronics may be contacted via their website (www.oatleye. com); by phone (02) 9584 3563; by fax (02) 9584 3561; or by mail to PO Box 89, Oatley, NSW 2223. Pack & post is typically $7.00 per order. siliconchip.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: ni.com/oceania COMING NEXT MONTH! * JUNE SALE ISSUE ONSDAY WEDNE AY 27TH M AT YOUR ! ENTS NEWSAG * these articles are planned for publication but may be postponed due to unforeseen circumstances. JED AVR200 Single Board Computer This compact unit is an industrial-strength single board computer employing the Atmel ATmega32 microcontroller. It has 8-bit RISC (reduced instruction set) architecture for very efficient programming in high level languages such as C and BASIC and can run in assembly code as well. The board has a host of input and output options, including I2C and is built entirely with through-hole components - no surface mount devices! The AVR200 has a very wide range of applications and is designed by JED Microprocessors. Wine cooler or freezer/fridge converter Convert your standard fridge to run as a wine cooler or better still, enable you to run a top-loading chest freezer as a very efficient fridge. Essentially, it is an adjustable thermostat which controls the fridge motor. AND COMING SOON . . . Oh, No! SILICON CHIP is about to go back on its principles (again!) and publish another valve amplifier circuit! Well, actually this one is different. Truly! Not only does this stereo valve amplifier give surprisingly good performance but it has very good styling – your wife/partner will love its appearance – even your mates will want one! It also uses novel technology to avoid the need for very expensive output transformers. From the publishers of SILICON Our most ambitious title yet: CHIP PERFORMANCE ELECTRONICS FOR CARS NOT A REPRINT: More than 160 pages of new and exciting projects never published before – all designed to get top performance from your car. FASCINATING ARTICLES: 7 chapters explaining your car – engine management, car electronics systems, etc ADVANCED PROJECTS: You’ll build controllers for turbo boost, nitrous, fuel injection and much more! We explain the why as well as the how to! Available direct from the Publisher ($22.50 inc postage): siliconchip.com.au 40 Silicon Chip Silicon Chip Publications, PO Box 139, Collaroy NSW 2097. Ph (02) 9979 5644; Fax (02) 9979 6503; email silchip<at>siliconchip.com.au or via our website: www.siliconchip.com.au Granddad’s 1930s text messaging? hellschreiber Data over UHF CB Younger readers may be unimpressed with yesteryear’s quaint technology but during the golden age of radio, beside such local 1950s staples as “Life with Dexter” and “Dad and Dave”, considerable international communications came via wireless signals on the adjacent short wave bands (3-30MHz). Gasp – you mean no global roaming text messaging? by Stan Swan siliconchip.com.au May 2005 41 Y and a chain-sawing woodpecker and es – pre TV, FM, satellites, GPS no doubt prompted many a spouse or (and certainly WiFi, mobile mum to hit the mains switch. phones, internet and email) things were pretty tough on the elecHellschreiber tronic communications front. Perhaps the most enduring of However that did motivate many, these short wave data signals was a myself included, to explore the tech1929 invention by Dr. Rudolf Hell nological magic then represented by (1901–2002!), known as Hellschreiber radio. Numerous ham radio and elec(German – Dr. Hells “bright writing”). tronics careers began when curious Aside from his engineering genius, youngsters twiddled the dial on the which also covered early TV and an family wireless and wondered how aircraft autopilot, Dr. Hell (just his the sound reached them from the other surname – nothing satanic!) was a side of the world. shrewd businessman and benevolent Along with such diverse short wave employer, with eventually some 2000 voice stations as the Voice of America staff in his German factories making and the BBC News, a huge volume radio gear, fax machines, scanners of powerful commercial, embassy, A 1940s era portable “Feld-Hell” and commercial printing presses military and news service information transceiver, as used by the (Linotype/Heidelberg) . passed as hideously sounding pulsed German army throughout WW2. On his 100th birthday in 2001 his data traffic over these bands. Tuning weak foreign stations amongst the cacophony of grateful hometown of Kiel (in northern Germany) even sounds that represented SW listening at that stage was often renamed a street “Dr-Hell-Strasse” in his honour. Hellschreiber is a form of 1-D fax and although ancient, an frustrating but entertaining experience, compounded by atmospheric static crashes, propagation fades, heterodyne is still considered (along with Morse Code) one of the most whistles, deliberate jamming interference and – oh yes – effective techniques for sending text information in weak or noisy signal conditions – both wireless and landline. analog dials. And you thought video games were noisy! However, unlike audible Morse decoding (which also It often sounded like a cross between an orchestra tune up Here’s a screen grab for the IZ8BLY Hellscreiber sound card software. 42 Silicon Chip siliconchip.com.au needs a trained operator), “Hell” uses 56kbps dial-up modems but simplicity the outstanding ability of our human and robustness ensure this narrow bandeye and brain to recognise shapes and width mode remains durable. distorted patterns. Sound card software Instead of deciphering with your ears, Hell is decoded as an image with With war surplus equipment just your eyes, via its signals traditionally a memory for most old timers and as printed out as characters on paper even post-war commercial equipment ticker tape for anyone who can read was scrapped in favour of modern datato understand. comms, Hellscreiber became a technology Also, the printed copy allows later that time almost passed by. consideration of confused noisy mes- It’s not every living person who has a In the early 1980s however radio hams sages - misheard Morse characters street named after them. Dr Hell had! began experimenting with fully elecmay be lost forever. tronic implementations, although these Such eye/brain data decoding has lead to Hellschreiber were not for the faint hearted. being in fact recently titled as a human readable “fuzzy The whole wireless data field however underwent an mode” – neither quite analog or totally digital. enormous upsurge only some six years ago, as cheap PC Hellschreiber became very popular in the 1930s, at a hardware and sound cards became well established. time when teleprinters were complex and costly, since it When combined with ingenious software, the PC sound allowed direct keyboard text transmission on machines that cards inbuilt digital signal processing features can offer near were cheap and reliable with few moving parts. effortless external data encoding and decoding. Its most celebrated use however came during WW2 with Such has been the phenomenal uptake of this approach, the German Army, when field portable electromechani- especially with radio hams on their short wave bands, that cal “Feld-Hell” units often were the only viable wireless brand-new weak signal data modes (CLOVER, PICCOLO, communication link under battle conditions and enemy PSK etc) have recently evolved, some even allowing fully jamming. digital Slow Scan TV (SSTV) images to be sent via low Such a character-forming tradition ensured wide sub- power HF radio transceivers around the world. sequent peace-time use, with commercial short wave Naturally such offerings are appealing for isolated services employing the mode for decades afterwards well communities or seafarers and of course emergency use – into the 1980s. Even SONY once made suitable units ubiquitous Internet cafes and mobile (cell) phones may under licence. be early casualties in disasters such as the recent Indian Ocean tsunami and earthquakes. Hell basics Although it’s now fully electronic and can be enhanced with sub modes such as FM-Hell, classic Hellschreiber involves on/off keying that portrays each text character (only capitals are used) as a series of vertically delivered dot pixels in a 7x7 matrix. In effect the outgoing keyboard characters are broken into a string of dots and then suitably reassembled at the receiver. Two identical lines are displayed so that legibility remains with even major errors and blank spaces and gaps between characters are also considered, as are half height pixels to increase resolution. Here’s a capital E, with tones black and silence white- Hell’s been rediscovered! Although perhaps best employed at lower frequencies 7 6 ! ! ! ! ! 5 ! 4 ! ! ! ! 3 ! 2 ! ! ! ! ! 1 1 2 3 4 5 6 7 Traditionally 150 characters were transmitted a minute, with each taking 400ms. This equates to 2½ ch/sec or about 25 “PARIS” words a minute – a comfortable typing speed for many! With 7x7 (49) pixels a character, each pixel duration is .4/49 = 8.163ms, so the data rate is 1/8.163ms = 122.5bps. Naturally this is very pedestrian beside even today’s siliconchip.com.au Close-up of a classic electro-mechanical Hellscreiber. Note the paper tape under the keyboard. May 2005 43 The human eye and brain combine for enhanced image decoding, allowing characters in “noisy” messages to be distinguished. when no other link is feasible, it’s now very easy to experiment with Hellscreiber over licence-free UHF CB. Enhanced modes, such as FM-Hell, offer great weak signal performance on even cheap CB sets– especially if used in conjunction with range-boosting antenna as outlined in the January 2005 SILICON CHIP. Virtually any old Windows PC and sound card will do, since even a Win98 slow-coach laptop will readily keep up with the slow data employed. Naturally other transceivers and approved bands can be used if suitably licensed, with the old 27MHz CB band particularly tempting. Software – what’s involved? Shareware Hellschreiber sound card software abounds, (Google “Hellschreiber”) with V4.0 of “IZ8BLY” by Italian ham Nino justifiably considered outstanding. In addition to classic Feld-Hell (and even Morse), it offers many enhanced modes, with the bolder characters and impulse noise immunity of FM-Hell particularly appealing. For extreme conditions, even meteor scatter and ultra- The IZ8BLY software will also allow normal Morse code to be sent and received. Messages can be “read” from the width of the bars, with a short “dit” visibly thinner than a long fatter “dah”. Hence SOS .../---/... slow modes are available. Screen data can be saved as a .bmp snapshot & then printed, although if emailing images you would first convert them to a smaller .gif file. The PC screen display can’t be taken as straight text to a spreadsheet or graph however. It’s an image, remember! Once downloaded (~1MB) and installed, you may only need to just start typing if you’ve two nearby sound card PCs both set to use the same mode. Such is the robustness of this technology that with suitably adjusted mic & speaker levels, even exchanging data as audio signals across a small room will usually be enough to display characters on the second PC – hard walls will show up as ghosted reflections. Modern switched-tone Hell implementations are quite musical incidentally, although the classic WW2 mode sounded “scratchy”. Although direct audio is an entertaining party or classroom trick, for proper wireless links simply turn on each UHF CB transceiver, set to a data channel and enable VOX (voice activated switching). Suitable sound card mic/speaker and CB volume ad- (Left, above:) Jaycar and DSE both stock handheld UHF CB’s that are typical of the cheap sets now on sale. Their units sport a multifunction socket for external mic and earphone connections, allowing easy acoustic coupling with a laptop’s mic and speaker by positioning CB mic to PC speaker and vice versa. For more professional linking a wired connection, simply made with 3.5mm stereo phono plugs, is preferable (and quieter!). (Right:) Positioning, perhaps by Velcro, headset mic to PC speaker and headphone to PC mic will allow easy acoustic coupling but you’ll hear the musical tones and room noises may corrupt data. 44 Silicon Chip siliconchip.com.au TO PC SOUND CARD INPUT TO 477MHz UHF CB CHANNEL 22 OR 23 SET TO “VOX” (eg, JAYCAR DC-1030, DICK SMITH D-1793, etc) POSSIBLE 3.5mm to 2.5mm ADAPTOR TIP SLEEVE RING TIP POSSIBLE LIMITING RESISTOR (~330kΩ) RING SLEEVE Three 3.5mm stereo plugs can be easily wired to connect the CB set to a PC soundcard, and as well as Hellscreiber may suit other soundcard digital modes as well. To save wiring a fiddly 2.5mm plug, just use a 3.5/2.5mm adaptor if using the DSE sets and even consider sacrificing a cheap headphone set for its flexible cables and single prewired plug. You may need to experiment with the dropping resistor value, CB volume and sound card settings. justing will usually be enough to trigger the transmitter, although naturally volume levels may be rather loud unless you place the CB speaker very near the PC mic. For more elegance, it’s suggested you use the headset and mic combo that is now available for most budget CB sets. These usually position nicely above the inbuilt mic and speaker of a laptop and allow much quieter acoustic coupling – Velcro or Bluetak assist in securing the PC mic to the CB speaker and vice versa. However for extended use room noises may interfere and the faint data tones may be annoying, as also may the PC SOUND CARD I/O TIP SLEEVE RING (NC) TO PC SOUND CARD OUTPUT MIC LINE TIP SLEEVE RING (NC) SPKR disabled background squelch noise if monitoring weak signals. Cable connection Direct cabling of two budget CB handhelds (DSE D-1793 & Jaycar DC-1030) was investigated and although these sets differ in their I/O socket size they were found electrically similar and readily converted with 2.5-3.5mm adaptors. To ease soldering woes on the 3.5mm stereo plug, a budget stereo headphone could be sacrificed for its shielded coaxial leads and CB plug pre-wiring. Such a cable allows a completely silent electrically-coupled connection direct to the soundcard but audio levels will almost certainly need tweaking on both your CB set and PC. Experimentation with a Toshiba P-233 480CDT laptop showed optimum Feld-Hell connection to its soundcard mic input was via a 330kW series resistor. FM-Hell however, being very impulse noise immune, behaved well on both the mic and line inputs without this limiting resistor. Applications Since anyone with suitable CB and PC sound card software can join in, it’s feasible for a UHF Hell chat room to evolve, suiting perhaps a scout or school group. Nino’s free software is not intended for commercial use however, so using it to co-ordinate big game fishing, courier deliveries, gas field exploration and the like may be frowned on. Perhaps the best use might be delivering weak telemetry data for an educational project – much as initially envisaged the UHF CB channels 22 and 23 would be suited for. Data images will eventually scroll off the screen top after a few minutes unless paused but the IZ8BLY software includes macros that may assist. Mmm – fancy a challenge? I wonder if a suitable Picaxe could be persuaded to generate Hell! SC References and web links: IZ8BLY software: www.geocities.com/iz8bly/ For convenience these are hot linked at www.manuka.orcon. net.nz/hellrefs.htm siliconchip.com.au May 2005 45 Salvage It! BY JULIAN EDGAR An automatic stopwatch timer Do you need to automatically record equipment running time? This stopwatch timer starts when power is applied to a low-voltage (12V) circuit and automatically stops when the power is switched off. When power is again applied, the stopwatch continues to count from where it last stopped. T HE AUTOMATIC stopwatch timer is a cinch to build and resetting the count is as easy as pushing a button. And by using a snap-action thermostat (salvaged, of course!), it’s even possible to automatically measure how long a temperature is above or below a set-point – ideal for environmental, solar heating and machinery monitoring. Because it uses salvaged parts, the complete project should cost you only a few dollars. Let’s see what’s involved. The components You’ll need an old digital watch with a stopwatch function, two relays (one a double-throw design), a capacitor and a pushbutton switch. Oh yes, and something to mount the components on! We used a small piece of pre-punched board laminate (unclad) and that was literally the only component that we had to buy new! It’s quite likely that you already have a digital stopwatch tucked away in a drawer – as fashions change, lots of people buy new watches even when the old one is still working fine. If you have to buy a new one, shop around at discount stores – it shouldn’t be too hard to find a watch that includes a stopwatch function for about $5. The unit shown here came from a watch I’d not worn in years – in fact, until I went looking, I’d forgotten I even had it! Relays can be found in a huge amount of discarded electrical equipment. The ones used here are quality Omron designs that were salvaged from an old radio transmitter that had been sent to the tip. Although they use 24V coils, they work fine in this application which is based around a 12V supply. Note that if you want to use the timer to monitor even lower voltage equipment, you’ll need lower voltage relays; eg, 5V. Don’t use this project to monitor voltage rails above about 15V DC, otherwise you will damage the circuit components. What about the 220mF 25V electrolytic capacitor used here? Well, again they’re everywhere in older electrical equipment – just take a look! Finally, the monetary pushbutton switch was salvaged from behind the front control panel of a VCR. All older VCRs with click-action pushbutton controls have this type of switch buried behind the faceplate. How it works This digital stopwatch timer will automatically measure how long low voltage equipment is running, making a cumulative count until reset. . Most of the parts can be salvaged for nothing. 46 Silicon Chip Fig.1 shows the wiring diagram (the tricky circuit was designed by John Clarke). Let’s look at Relay 1 first – its coil is wired in parallel with whatever device we’re monitoring – so when the device is on, so is Relay 1. This closes the Normally Open (NO) and Common (C) connection, feeding power to the coil of Relay 2. The 220mF capacitor is wired in series with Relay 2’s coil, so Relay 2 will pull-in only for as long as it takes the capacitor to charge. In this case, using the relays and capacitor specified, that takes about 0.1s. Relay 2’s NO and C connections are wired to the contacts that normally start and stop the stopwatch. siliconchip.com.au you work out which are the Normally Open (NO), Normally Closed (NC) and Common (C) relay contacts. Often there is a small diagram on the relay itself, or you can use the continuity function of a multimeter to check the contact behaviour. Take care when wiring in the capacitor, as this device is polarised. Its negative side is shown by a line of “-” symbols near one of its leads. Fig.1: two relays, a capacitor and an old digital watch are used. The circuit is configured so that the start/stop button contacts of the watch are momentarily connected by Relay 2 when power is applied and the same occurs when power is removed. So when power is applied to Relay 1’s coil, Relay 2 is momentarily pulled in and the stopwatch is triggered. That’s the starting pulse – now what about the stopping pulse? When power is removed from Relay 1’s coil (ie, the monitored device is switched off), Relay 1’s NC (normally closed) and C terminals are connected. This immediately provides a path for the capacitor to discharge through the coil of Relay 2, so again momentarily pulling it in. Bingo! – we now have a switch-off pulse. The reset button simply bridges the watch’s original reset contacts. Building it Using It Fig.2: here’s how to use the stopwatch timer to detect how long a temperature is below a setpoint. Thermostats found in much discarded equipment (eg oil-filled electric heaters) open when the temperature rises above a setpoint. Wired as shown here, the count will stop when this occurs. The first step is to remove the rear of the watch, carefully pull out the workings and inspect the start/stop and reset buttons. Normally, a single common is connected to a PC-board pad to start and stop the count, and to another pad to reset the timer. You need to solder a wire to the common and then two others to the start/stop and reset pads. As might be expected, it’s easier to do this in some watches than others. Note too, that in some watches, the common comprises a “springy” stainless steel strip which is impossible to solder. If this is the case, bend the strip over and crimp it to the wire. Once you have the three wires coming from the watch, check that you can start, stop and reset the stopwatch. siliconchip.com.au After that, it’s just a case of following the circuit diagram. Make sure that Testing the unit is easy. First, connect the +12V and earth leads to the power supply, then connect the 12V trigger wire to +12V. The timer should start running and continue for as long as this wire is connected to the +12V rail. Now disconnect this wire – the timer should immediately stop. Finally, press the reset button and – well, you can guess what should happen! Note that if you just brush the trigger wire against the +12V rail, the relay contacts may “bounce”. This can result in the timer getting out of sequence – ie, running when it should be stopped and stopped when it should be running. If this happens, manually bridge the start/stop terminals to return it to the correct operating sequence. If you find that both relays click but the device isn’t working as it should, try increasing the value of the capacitor. If the relays have clear covers, it’s interesting to watch Relay 2 quickly pulsing when the watch starts and stops. When running, the prototype draws about 50 milliamps (50mA) so if you are monitoring a battery-operated device, this should be considered. SC Any old digital watch that has a stopwatch function is potentially suitable for this project. However, the ease with which wires can be soldered to the switch pads varies from watch to watch. When selecting the watch you should also take note of the maximum time the stopwatch display can show. May 2005 47 SERVICEMAN'S LOG Warranty claim? I don’t think so! It must be the season for lightning – there was one last month and another dead’n, which came in “under warranty”, looked suspiciously like lightning as well. But who am I to argue? We had a newish 2004 Panasonic TC21PM50A (GP-3 chassis) come in under warranty with the fault description “dead”. Apart from the dealer receipt, no other information was supplied. It was soon apparent that the switchmode power supply was more or less working and supplying 140V at the cathode of D854 (TPA10). But the 14V rail was running at 38V from the cathode of D855 (at standby it should be only 7.5V). This had destroyed the smoothing electros C862, C880 and C2380, all of which are rated at 16V. This also meant there was over 100V across Q850 and R850 (47W). These were replaced but this didn’t account for why the low voltage rail was so high. Even though the 140V was correct, I felt that somehow the feedback wasn’t quite right and so IC802, the 140V optocoupler IC driver was changed, as was IC851, the switchable 8V and 5V IC regulator. But nothing significant happened until D860, the PC123 optocoupler, was found to be leaky on both sides. Replacing this brought the voltage down to 14V (7.5V standby). However, the 8V line TPA8 to the microprocessor (IC601) on pin 39 was still 0V and this was due to a short inside the IC itself. Replacing the IC fixed this and the set came on. There was now sound but no picture. There was a white raster with a black bar beneath it, one-third of the way up the screen. Replacing the EEPROM (IC1103) finally resolved this last issue. Methinks this was a bit more than a warranty claim – I suspect lightning had a lot to do with it! Extremely loud noises The summer months bring on the monsoon type weather with high humidity and dampness which eats away at the insulation of extra high voltage circuits. In the good old days, we would call this “tripler weather” when triplers would fail and my cup would runneth over with work and the kids would grow fat on the bountiful fruit thereof. Nowadays it takes something like a Chieftain or Leopard tank to get through the insulation but still it does happen a lot. I had an LG CF-25H30N (MC-74A Items Covered This Month • Panasonic TC21PM50A (GP-3 chassis • LG CF-25H30N (MC-74A chassis) • • • • • LG LCD RT-13LA60 NEC MT840G Yamaha RX360 amplifier Onkyo TXD5676 amplifier Blaupunkt CS82-103VT FM 542.60 chassis • Panasonic Tau Giga TX80P300A (Euro 7A chassis) • Sony KV-L34SN11 (G3F chassis) • Philips 29PT8419/79R (EM1L chassis) 48 Silicon Chip siliconchip.com.au chassis) come in making extremely loud noises. The flyback transformer was arcing violently and had to be replaced. The client naturally wanted to know the cost of this exercise and I gladly obliged. The quote was accepted and the part ordered (61742-6229L) but I wasn’t to know that this fault masked another one behind it. When the picture was restored, I noticed that there was a vertical deflection problem with top foldover and retrace lines. I started by replacing electrolytic capacitors C301, C302 and C307 (as recommended by LG) and checked D305 and D306, before ordering and replacing IC303, the TDA8350Q vertical output amplifier. Before this could come in, the client was back on the phone asking about the delays. After all, it had been a full two weeks since he had brought it in. (I do hope he never has to get in line for elective surgery in our wonderful National Health Service!). I explained about this secondary siliconchip.com.au problem which apparently he was aware of but had neglected to tell me. I was made to agree that I would fit the parts for free but he would pay for them. This vertical problem became progressively worse whilst on soak test until finally the set wouldn’t start but just pulsated. I fitted the new IC which restored the sound and picture but unfortunately the fault was more or less the same. I was now beginning to panic. Servicing vertical amplifiers is very similar to servicing audio amplifiers which have lots of feedback. Oscilloscopes aren’t much use because you are not able to deduce where the distortion starts as it is there all the way around the loop. Only by disabling the feedback can you sometimes get a handle on it but more often than not, it will produce distortions of its own, invariably tripping the protection circuits. The best way is the good oldfashioned method of using voltmeter checks and hopefully with a good circuit. I had the circuit and and on checking all the voltages on the IC I soon discovered the 48V rail to pin 8 was down to only 19V. It didn’t take an Einstein to realise that you cannot drop 29V across a 10W ½W resistor without dire consequences. FR311, a fusible resistor, had of course gone high. Replacing it fixed the problem completely. Cockroach execution Sometimes we do get strange problems and faults, like the new LG LCD RT-13LA60 which arrived D.O.A in the workshop. It didn’t take long to see that nearly all the ICs had been blown apart. But why? A new board was ordered and it was only when removing the old one that we find the answer on the other side. A cockroach had been electrocuted across the switchmode power supply, causing the voltage to rise dramatically on the secondary and blowing the ICs – see the photos! The current generation of LG Plasma May 2005 49 Serviceman’s Log – continued replaced separately. LG PDPs are used in most brand-name plasma sets. Yellowish projector Display Panels (PDP) are quite impressive with a half-life (brightness) of 60,000 hours (about 30 years of normal usage) while the contrast levels using binary counting rising from 5000:1 to 10,000:1. Dual Scanning in the larger PDPs reduces address timing and increases sustain time, giving more brightness and a dynamic range 2.5 times that of single scan. Pixel failure is substantially reduced (the maximum allowed is 35 cells on a fully scanned 60” PDP when viewed from 2.5 metres (3 x height) at between 100 – 200 Lux). There are four cell defects: Non-ignition dot (dark defect); Unstable dot (flickering); Non-extinguishable dot (brightness defect) and Uncontrollable dot. Cell defects do not increase or progress as time goes by. Most problems are there at birth and consequently can be picked up in the warranty period. Service repairs are to board level only. The only electronic chips on the PDP are the X amplifiers which are not replaceable. If any of the 100W SMD anti-surge resistors are blown, the chip is unserviceable and the display has to be replaced. All other components are on separate boards which can be We had a 3-year old $5000 NEC MT840G progressive scan projector come in from an ex-technician. The fault was no picture and he requested that a new lamp be fitted. The new lamp (worth $800) was ordered and fitted but when the picture came on we noticed that it had a yellowish tinge. We contacted the client who said he knew about this but thought it was because of the lamp reaching the end of its life (2000 hours) and a new one would fix it. Of course, if it wasn’t the lamp that caused the yellowish picture, it would be the LCD drive panel that was discoloured. That would cost an additional $3500 to replace! The client took the projector home and a few months later started to complain loudly about the yellowish colour and wanting his money back. At that stage we contacted NEC directly and they looked into it. The first thing they checked was the built in usage timer to find that the client had already used the new lamp for more than 40 hours. The battle is now on between NEC and the client but I don’t think he will get his money back after using the set for so long. Home theatre no-show Two completely different home theatre audio amplifiers arrived with similar no-go symptoms. One was a Yamaha RX360 and the other an Onkyo TXD5676. Both had their microprocessors in protect mode. Apart from roughly having the same type of architecture in their block diagrams, these amplifiers were quite dissimilar. The power-down detectors and power failure detect input pins on both processors are normally held high (5V), in one case by a resistor to the 5.6V rail (the resistor went high), and in the other case by a 5.6V zener to the 13V rail (the zener went open). We changed all the electrolytic capacitors on these power It didn’t take long to see that nearly all the ICs had been blown apart. But why? Aha! Could this cockroach be the culprit – having been executed in the switch-mode power supply? 50 Silicon Chip siliconchip.com.au rails as well as the battery backups. No other faults were found. Blaupunkt repeat Before the Grundig factory was finally sold off eighteen months or so ago they used to manufacture TVs for both Grundig and Blaupunkt. The Grundig chassis began with the prefix CUC and the Blaupunkt FM. On the Internet you can download a lot of the equivalents which means you then get access to purchase a schematic diagram. Recently I had to repair a Blaupunkt CS82-103VT which I had done 18 months ago. The chassis is an FM 542.60, which is the same as the Grundig CUC7880. The fault was virtually the same. It was flickering at the top of the picture with intermittent top vertical linearity only when the set is hot. Last time I had changed the TDA8350Q vertical IC, C557 (4700mF 35V) on the 16V rail supply, C552 (100mF 63V) on the 45V rail and C438 (4.7mF 100V) on the East West Circuitry. There are no other electros in the vertical deflection circuit. This time I replaced the IC again and also the two fusible resistors in the supply rails: R552 (2.2Ω) and R525 (0.68Ω). That fixed the fault, but how long will it last this time, I wonder? Monster Panasonic I did a service call on a 2000 Panasonic Tau Giga TX80P300A (Euro 7A chassis). These 80cm televisions are so heavy that the only practical approach is to take the chassis and fit it into another set we have here in the workshop. There have been a lot of problems with the Audio Digital Processor DP Panel causing intermittent no sound. This board is now on its fifth revision and the problem concerns the IC2510 ROM. Because this set offers full digital and optical inputs (PCM, AC-3, DTS and Dolby Prologic) for sound, everything has to go through this complex processor. It is a surface-mounted IC which suffers from poor flow soldering a well as feed-through soldering on its double- siliconchip.com.au sided printed tracks. This requires a steady hand and the right set of tools to rework. An exchange board is available, TNPA1727ZA/R, at a cost of $300! On this particular service call, the fault report was that the set was dead and pulsating. I measured a complete short circuit to ground on the main +144V rail (TPD15) and it didn’t take long to find this was due to Q551 (2SC5 591000RK), the line output transistor on the D Board. Removing this transistor fixed the short but fitting a May 2005 51 Serviceman’s Log – continued D855 FLYBACK TRANSF. TPD15 +144V T801 9 D558 SHORT CIRCUIT FAULT 2 TPD32 +220V D6 1 L3 HORIZ OUTPUT 10 5 Q551 SHORT CIRCUIT FAULT 1 T551 D385 D6 3 1 (ON CRT BOARD) L3 OHM METER MEASURED SHORT CIRCUIT BOTH WAYS This flyback section of a Panasonic set had two faults, involving Q551 and D558. The latter short circuit diode was particularly hard to find. new one seemed to restore the short circuit. There was something strange going on here, I thought. Gradually unsoldering and resoldering parts of this rail, I could remove and restore this short at will but it was still not making any sense. Methodically, I worked away at this circuit until I found that unplugging D6, which leads to the CRT socket L Board, removed the short. Gotcha! I thought it had to be on the CRT socket board. Another fruitless half hour made me realise that although the short went through plug D6 and L3, the short was still back on the D board. How could this be? There are only four conductors on this lead: Pin 6 = Ground; Pin 5 = Heater; Pin 3 = 144V and Pin 1 = 220V. Being a bear of very little brain, it took some time for the penny to drop. In fact, there were three diodes involved. On the CRT board the 144V rail is connected to the 220V rail via diode D385 and the 220V rail is supplied via a diode D558 from pin 1 of the flyback transformer T551. What happened was that D558 went short circuit. So the 144V rail was measuring short circuit one way through D558 and the other way through its own diode D855. Replacing D558 fixed up all the faults. Refitting the chassis was a bit nasty as the plugs and sockets used vary from model to model according to its options, so care has to be exercised when refitting them - in particular on the small signal A board. Help for the opposition The opposition service centre 52 Silicon Chip in town brought in a 34” Sony KVL34SN11 (G3F chassis), with no picture and no on-screen display. Judging from all the soldering all over the place they had tried this and they had tried that but they had got nowhere. I guess if you do enough of these sets, you get to know their foibles. In this case, the cause was that someone had tweaked RV709, the screen control, with the result that it was now outside the capture range for the ABC circuit. This promptly cut off the video output stages. Correctly adjusting this lets the set measure the beam current and set the greyscale automatically. Resetting it fixed the problem. Weird Philips A 2001 Philips 29PT8419/79R (EM1L chassis) had the weirdest fault. On switch-on it would start as a white line across the screen before changing to the most amazing and beautiful modern art pattern all over the screen (see photo below). You could just see some semblance of a picture in the background and the sound was OK. I established first that the horizontal deflection was OK and not leaking or arcing into the vertical timebase. The oscilloscope showed a vertical pulse of sorts was being delivered by the vertical output IC7620 (TDA8177) and the DVM measured correct voltages on each of the seven pins. The vertical deflection yoke has ten additional correction circuit components not shown in the service manual and its whole impedance measured 7.1W. I marked and then twiddled the YH and YHc controls but they made only a small difference. I then unsoldered the additional connection circuitry so that I had only the vertical deflection coils connected. Still no difference. I pinched the deflection yoke out of an A10A chassis and swapped over the leads. After resetting the screen voltage, I could at last see a picture. My conclusion was that the vertical deflection yoke was shorted. I couldn’t see where and so I couldn’t fix it. Unfortunately, this is not sold as a spare part, only as part of the complete picture tube assembly which is extremely expensive – getting onto $900. A word with Mr Philips and a swap was arranged for the client. SC This surreal pattern was produced by a fault in the vertical deflection coils in a Philips TV. siliconchip.com.au [ May 2005 ] MIDI Theremin Synthesiser Kit Deluxe Map Distance Calculator New model! This new Map Distance Calculator can operate in metric or imperial units, as well as nautical miles for marine or aviation applications. Roll it forward to add distance, or backward to subtract. It has a backlit display and small torch for night use. Measures 155(W) x 35(H) x 23(D)mm. FM Stereo Transmitter with LCD Full FM selection! Play your iPod/CD/MP3 player through your car stereo. Select any frequency in the FM band. Requires 2 x AAA batteries. Cat. AR-3115 $ .95 59 39 Mini Electric Toy Safe Remote Controlled Battle Submarines - Pair Underwater battle fun! A new twist to our everpopular radio controlled submarines. They incorporate a combat mode to seek and destroy your opponent by tailing and shooting them down! Once shot, the opposing submarine is disabled for 20 seconds. They are switchable to normal mode if you are not in the mood for a bloodbath! Cat. XC-0377 $ .95 More compact! This mini version of our regular toy safes has keypad entry and great sound effects. It measures 132(L) x 105(H) x 122(D)mm, and A great way to has a coin slot save pocket in the top. money! 159 Cat. GH-1312 $ .95 19 KIT OF THE MONTH AC/DC Current Clamp Meter Kit for DMMs Cat. GT-3043 $ .95 pr 49 INOX Lead Acid Battery Conditioner Revive lead acid batteries! When lead acid batteries sit around, sulphate builds up on the plates and separators. INOX basically disolves it, to bring dead batteries back to life. •One bottle treats up to Cat. NA-1420 $ .95 N70Z (4WD, boat) size batteries. Measure up to 900A with your multimeter! Ref: Silicon Chip Sept 2003. If your meter can measure millivolts, you can use it to measure high current. Just build this kit and plug it in. It is a safe and easy way to measure high current, especially where it is unsafe to contact the source itself. The kit is supplied with PCB, case, silk screened panel, Hall-effect sensor clamp, core, and all electronic components. Note: The iron-powdered core has been factory pre-cut. This would be Cat. KC-5368 very tricky to do with only household $ .95 tools. 34 8 Wireless Weather Station with Wind CAR AM PLI FI ER CLEARANCE Direction & Rain Gauge 2 x 84WRMS MOSFET Wireless sensors! •2 x 84WRMS <at> 4 ohms. •1 x 234WRMS <at> 4 ohms. •<0.1% THD. •10Hz – 30kHz freq range. Limited qty. Was $199 SAVE $60 4 x 50WRMS MOSFET •4 x 50WRMS <at> 4 ohms. •2 x 150WRMS <at> 4 ohms. •<0.1% THD. •10Hz – 30kHz freq range. Limited qty. Cat. AA-0438 $ .00 Was $219 Cat. AA-0432 $ .00 139 SAVE $50 169 •2 x 150WRMS <at> 4 ohms. •2 x 230WRMS <at> 2 ohms. •1 x 450WRMS <at> 4 ohms. •<0.08% THD. •20Hz -30kHz freq range. Limited qty. Was $289 SAVE $90 Everyone likes to talk about the weather, and now you can do it with real authority. The system monitors inside and outside temp, air pressure, rainfall, humidity, wind speed and direction, and wind chill factor. Check our website for all the Cat. XC-0293 features. $ .00 249 2 x 150WRMS MOSFET NEW STORE IN ALEXANDRIA! Cat. AA-0434 $ .00 199 647 Botany Road ROSEBERY NSW 2018 Ph: (02) 9699 4699 NOW Fax: (02) 9699 4966 OPEN FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au Exclusive to Jaycar! Ref: Silicon Chip April / May 05. Instead of generating a Theremin like tone, it relies on a MIDI accessible synthesiser or a computer with a sound card. When set up (usually with a computer), it will play up to 120 different instrument selections in 15 types, by 8 variations. Sequencing software is required for use with a computer, but is available for download from the internet (details supplied with kit), as well as commercial sources. There are loads of features and functions, too many to list here, so check out our website or the Silicon Chip articles for Cat. KC-5410 full details. Kit supplied with PCB, case, $ .00 LCD, and all electronic components. Wind Powered Generator Experimenters Kit A great learning tool! This small scale project enables you to build a real working wind generator, and then use it for experimenting. It can supply up to 10VDC <at> 1A (depending on wind speed), and features an onboard 330uF capacitor so you can store the energy for later use. Kit includes all parts to make the generator, fan assembly, and pedestal. Stands 250mm high. Cat. KJ-6696 $ .95 49 Long Range 120m Twin Beam Driveway Monitor 240m range indoors! Now you can reliably monitor an entryway of up to 240m indoors, or 120m outdoors. Installation is easy thanks to built-in laser guides, and dual beams help eliminate false alarms from birds or debris etc. See website for details. Cat. LA-5199 $ .00 1 Farad 20V Capacitor with Voltage Display 299 Car audio enthusiasts please note! This massive capacitor will help stabilise the voltage levels in a high power stereo installation. A voltage display keeps you informed of voltage Cat. RU-6750 $ .95 levels, and mounting hardware is included. 99 10mW Green Laser Module Extremely bright! This laser module consists of a 10mW laser diode, lens, and driver PCB. Simply connect a 3VDC supply, and you have a great high Cat. ST-3117 power laser. •Datasheet included. $ .95 •Measures 65(L) x 11(dia)mm. 149 1 TV/Video Capture Systems HIGH DEFINITION Digital Terrestrial TV Card for PCs HDTV on your computer! Watch either high or standard definition TV on your PC! It supports wide-screen (16:9) and standard (4:3) aspect Cat. XC-4819 $ .00 ratios. 300k Pixel SurfCam USB Web Camera USB 2.0 HIGH DEFINITION Terrestrial TV Tuner for PCs Top quality reception! No need for physical hardware installation, just plug it into your USB 2.0 port for HDTV. It operates in enhanced 16:9 format with software supplied for DVD making and Cat. XC-4814 manipulation. See our website for system $ .95 requirements. 249 XPERT DVD Maker Convert all your old VHS tapes and camcorder cassettes to DVD! XPERT DVD Maker converts on the fly, so there is no need for excessive amounts of free disk space. All you need is a DVD burner and you can store your memories forever! Cat. XC-4811 $ .00 149 149 USB 2.0 Video Capture Box Cat. QV-3090 $ .00 99 19 USB Phone Charger / Mini Massager 2 Cat. GG-2268 $ .95 12 2.4GHz Dipole Antenna 5dB gain! Features a 700mm lead and a magnetic base. Cat. AR-3270 $ .95 19 2.4GHz Yagi Antenna Cat. AR-3272 $ .95 129 2.4GHz Lightning Protector 35 64MB USB 2.0 Flash Disk with Built-In Card Reader Extremely versatile memory device! As well as having 64MB of on-board storage, this flash disk also has a card reader for use with SD, MMC, and Memory Cat. XC-4768 Stick (including Pro and $ .95 Duo). Full speed USB 2.0 data transfer and a compact 28(W) x 80(H) x 20(D)mm package. Simple PC security! Keep the small transmitter with you, and when you are out of range (around 2m), it puts your PC into "lock mode". When you return, it resumes normal operation. Transmitter, receiver, software and drivers supplied. Cheap protection! Connect this unit inline with your antenna to stop lightning strikes on the antenna reaching your valuable equipment. "N" plug to socket connection. Cat. AR-3278 $ .95 69 Wi Fi Hot Spot and RF Bug Detector Quickly check for wireless network access, or wireless devices! Now you can check for wireless connectivity without having to boot up your laptop! It measures just Cat. XC-4885 75 x 37 x 10mm with $ .95 an LED strength meter. 39 Multi-Network Cable Tester Cat. XC-4842 $ .95 69 Portable iPod / MP3 Player Dock and Speakers Featuring 1.5" micro speakers, & an internal amplifier, they sound great. It all folds up to a neat 286g package when not in use too. Powered by 4 x AAA batteries. •iPod not included. Quick and easy! Test UTP, STP, Coaxial, and Modular network cables by automatically scanning the wires for continuity, mis-wiring and polarisation. It uses a remote terminator for testing of installed or uninstalled Cat. XC-5075 network cables. $ .95 Was $69.95 SAVE $30 39 Multi-Network Cable Tester with Pin-Out Indication Cat. XC-5163 $ .95 89 Image Media Player USB Magnifier Lamp Utilise USB power and take the strain off your eyes. A 50mm diameter glass lens provides great magnification while a built in lamp Cat. ST-2809 $ .95 lights your work. Improved range! Increase the effective range of your wireless network or AV sender transmission. They are supplied with mounting hardware and SMA connection. There are two types available: 8dB gain! If features high gain for excellent transmission range. USB Wireless PC Security Lock No more fading memories! Transfer all of your VHS, Betamax, and camcorder tapes to DVD using your computer’s DVD burner. It includes powerful editing software to add colour and transitional effects, as well as sound tracks if desired. Supports composite and S-Video inputs, and PAL or Cat. XC-4809 $ .00 NTSC sources. Streaming full resolution video on your PC! Preview, record and playback video, or burn to CD or DVD. This is a great way of making DVDs if you own an analogue video camera. Includes capture and editing software, supports MPEG1 and MPEG2. Video conferencing and more! It uses a 300k pixel colour CMOS sensor with auto exposure and white balance for optimum performance. Software included for creating Cat. QC-3223 greeting cards and $ .00 photo albums. 64 USB 2.0 DVD Maker No flat batteries, no sore muscles! Charge your mobile phone from your USB port, or ease away the stress of the day. It suits Nokia, Siemens, Samsung, and Sony Ericsson phones. Massive portable storage! Instantly add gigabytes of storage to your PC or notebook. You can use any 2.5" IDE HDD, and then plug it into your USB 2.0 port for super fast backup, transfer, and Cat. XC-4678 $ .95 storage. Includes carry pouch, cable, and drivers (only required for Win98). 49 179 See cat page 312-314 for more 2.4GHz stuff! 2.5" IDE - USB 2.0 Hard Disk Drive Case 2.4GHz Wireless Antennas Digital slide shows on your TV! Just insert your memory card and plug it into the composite input on your TV! Cat. XC-4857 It also acts as a card reader when $ .00 connected to your PC. 149 USB Radio and Remote Control Radio on your PC! Receive, play, and record FM radio stations through an ultra-stable phaselocked-loop (PLL) tuning system for superior reception. Includes an IR remote control which can also be used with software such as MS PowerPoint. Visual indication! Suitable for use with UTP, STP, Coaxial, and Modular network cables, it features two LED bar-graphs to indicate pin connection. You can then quickly see any incorrect Cat. XC-5076 connections. $ .95 Was $99.95 SAVE $50 49 Network Cable Tester for RJ-12, RJ-45, and USB Even checks USB! Check the condition of your RJ-45, RJ-12, and USB cables. Press the test button, and the 13 LEDs indicate any open or short circuits, and cross wiring. SAVE Was $119 $40 Cat. XC-5077 $ .00 79 Network Cable Tracer Cat. XC-4880 $ .95 79 Invaluable for technicians! This tone generator is a highly practical network installation and troubleshooting tool. The insulated inductive pickup amplifies the tone signal, SAVE $70 and the tracer can also be used to check telephone line status (ring, Cat. XC-5083 busy, idle). $ .00 Was $199 129 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au MPEG4 Media Player Great for the car or home! Here is a great way to enjoy movies, music, and picture slide shows on your TV or PC monitor. It accepts many common memory cards so all you need to do is load the files on the card, pop it in and you're away! The IR remote control operates all functions, including great features such as image zoom, image rotate, slide shows, and various other great functions. It supports MPEG4 encoded files in MPG, DAT, and AVI format, and Cat. XC-4865 $ .00 can also play music and image files. See our website for full details. Measures 125(W) x 22(H) x 83(D)mm. 199 Noise Cancelling Headphones Sleep soundly! They are designed for use in noisy environments such as an aircraft or cars reducing background noise by as much as 15dB. Powered by two AAA batteries (included), they come with a 1.8m lead Cat. AA-2054 terminated with a $ .95 3.5mm stereo plug. UHF/VHF/FM Indoor TV Antenna Includes FM! Directional fine tuning is possible, with a variable direction inner reflector. Wide frequency band from 40 - 890MHz. 75 ohm impedance with SAVE coaxial cable and plug. $4 Was $21.95 5 17 Scart Plug to RGB Video Adaptor 4 Way Optical Switch Box Simple solution! Optical signals cannot be electronically switched, but this switch box provides a solution. Four inputs (1 x 3.5mm, 3 x Toslink), 1 Toslink output. Cat. AC-1675 $ .95 19 3 Piece Surround Sound Add-On Enjoy the surround sound experience. Select between two sources Cat. AC-1677 $ .95 and distribute to one or both pairs of speakers. 19 2 Way Speaker Switch Switch between two speaker Cat. AC-1679 $ .95 pairs quickly and easily. 19 139 240WRMS Subwoofer Amplifier Module The centre speaker contains a screened 4" mid/woofer, and 2" tweeter with a 6 ohm impedance. The two rear speakers contain a 4" full range with a 4 ohm impedance. Cat. CS-2465 SAVE $ .95 2004 Cat Price $99.95 $40 High power, low price! If you want plenty of power, then this module is for you. It will give you 240WRMS <at> 4 ohms, or 150WRMS <at> 8 ohms. It has an automatic shut-off when there is Cat. AA-0501 no input signal, and $ .00 more. Was $329 14 Source and Speaker Switch 78 Great home theatre! Add this module to a subwoofer for excellent bass performance from music and movie sources. Line and speaker level input/outputs. 80WRMS <at> 4 ohms, 60WRMS <at> 8 ohms. Cat. AA-0503 SAVE $ .00 Was $159 $20 No more tangles! The cable retracts into the holder when not in use. Includes gender change adaptor. Cat. WV-7368 $ .95 Control the music around your home! With these inexpensive units, you can control volume, select speakers, and even sources! It allows you to wire your home with sound, while maintaining flexibility. See website for full details. No more limitations! Walk freely around your home listening to your favourite tunes. Up to 100m range. Use internal rechargeable Cat. AA-2000 SAVE $ .95 batteries. $30.05 Was $109 80WRMS Subwoofer Amplifier Module 7 Metre Retractable Coaxial Lead Speaker / Source Control Wall Plates UHF Wireless Stereo Headphones 399 SAVE $20 49 12 or 2 for $8 29 SAVE $30 A cheap alternative! It uses standard SD memory cards (available separately), giving you a cheap, high capacity MP3 player. Measures just 57(W) x 45(H) x 12(D)mm. Cat. GE-4003 $ .95 Was $69.95 Simple, but effective! Scart plug to 3 x RCA sockets, Cat. PA-3667 $ .95 bi-directional. Labelled by Ford, made by Koss! Made in the USA, they are the end of a custom production run. Top quality, great price. Two sets supplied, 2.5m lead. Cat. AA-2046 $ .95 Ltd qty. SAVE Was $39.95 $10 Add a new dimension to your home theatre! It uses a well designed bass reflex enclosure for the best performance. •375(W) x 510(H) x 410(D)mm. Cat. CS-2456 Was $459 SAVE $ .00 $60 59 70W 12 Step Stereo Loudspeaker Attenuator Attenuates by up to 46dB on an 8-ohm system for tailored listening Cat. AC-1685 $ .95 levels. 39 LONG DISTANCE VIDEO TRANSMISSION – WITHOUT SIGNIFICANT SIGNAL LOSS Use video baluns and Cat5e cable to get much longer cable runs than possible with regular cables. Composite Video Cat 5 Video Balun SAVE $30 299 350WRMS Subwoofer Amplifier Module with Remote Control Power to spare! This module has enough power to shake your foundations loose. It provides a massive 350WRMS <at> 4 ohms, or 240WRMS at 8 ohms. It has an IR remote control for volume and crossover frequency, Cat. AA-0508 and more. Was $379 $ .00 Video and audio! Transmit video and audio up to 300m colour, or 600m B&W. •75(L) x 55(W) x 25(H)mm. Cat. QC-3424 $ .00 One required at ea each end. 95 RGB Cat 5 Video Balun SAVE $50 Ideal for home theatre! Send RGB up to 300m without degradation. •110(W) x 77(D) x 24(H)mm. Cat. QC-3429 One required at $ .95 ea each end. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 Cat. LT-3130 $ .95 Ford / Koss Headphone Twin Pack 12" 150WRMS Powered Subwoofer 329 44 Fantastic value! They have a frequency response of 6 to 20kHz and 40WRMS power handling. Cat. CS-2218 $ .00 ea 30WRMS 6.5" Home Unit Subwoofer 139 How’s your TV reception? This antenna has a built-in amplifier with 24dB gain on VHF, and 20dB gain on UHF with gain control. Powered directly from 240V mains. See Cat. LT-3135 website for details. Ltd qty. SAVE $ .95 Was $64.95 $20 Car Super Tweeter Bargain 49 Great sound, compact size! Now there is no excuse not to add a sub to your HiFi or home theatre system. A 30WRMS amp powers the 6.5" subwoofer. Mains powered, Cat. AA-0512 great sounding $ .00 bass. Was $169 Memory Card Type MP3 Player UHF / VHF Indoor TV Antenna / Amplifier INTERNET> www.jaycar.com.au 79 S-Video Cat 5 Video Balun Huge distance! Transmit your S-Video signals up to 300m. •69(W) x 25(D) x Cat. QC-3423 $ .95 22(H)mm. •One ea required at each end. 39 VGA Cat 5 Video Balun - Pair Unbeatable! Transmit your VGA signals up to 135m - much further than otherwise possible! •110(W) x 77(D) x 24(H)mm. Supplied as a Cat. QC-3428 transmitter and $ .95 receiver pair. 149 3 Vibrating Pillow LCD Alarm Clock Colour Master Colour Changing LED Lighting Kits Fun and funky! Mount them in laminate or wooden floors, walls, or even ceilings for great mood lighting. They can be changed from red, blue, or green, auto changing or static. Supplied with controller and mains plugpack. Lights measure 80(Dia) x 6(H)*mm. *6mm protruding from mounting Two packs available: Four Light Pack Includes 4 x round LED fittings, 12.5m of cable, and controller. Eight Light Pack Includes 8 x round LED fitting, 22.5m of cable, and controller. Cat. ST-3880 79.95 $ Cat. ST-3882 139.95 $ Time Ball - Electronic Game of Skill Hours of fun! Test your skill by manoeuvering the ball over the plus score numbers, and not over the minus score numbers. Three different ways to play. Radio Controlled Clown Fish Swims underwater! It has full manoeuvrability with forward, reverse, left and right and a power dive function. SAVE $5 24.95 $ Radio Controlled Submarines Both Types 24 $ .95 Cat. TH-2137 29 $ .95 49 29.95 4 Cat. ST-3038 9.95 $ OGGZ - Colour Morphing Mood Lights Set a romantic atmosphere! These rechargeable wireless lights slowly change from one colour to the next, and have a soft glow for romantic or mystical effects. They are charged on their base, and run for up to 6hrs. Cat. GH-1047 1 Piece Set Cat. GH-1047 $ .95 Includes 1 OGGZ, charging base, and mains adaptor. Cat. GH-1048 3 Piece Set Cat. GH-1048 $ .95 Includes 3 OGGZ, charging base, and mains adaptor. 34 69 As seen on Channel 9’s Merrick and Rosso Unplanned, dubbed... The Pain Machine! 29 $ Get this! Not only a normal flashlight but 8 extra buttons generate those weird sounds you hear in the "Addams Family" or Cat. GH-1550 a fairground Ghost Train! You get: evil $ .95 laugh, wolf howl, creaky door hinges, thunder storm, Witches cauldron, Jacobs’ ladder etc. Colour filters clip over the light to add atmosphere! 24 Great fun for the whole family! The missiles launch spectacularly into the air with the use of the hand pump. They launch Cat. GT-3006 $ .95 over 30m into the air! 5 LED Red Bike Tail Light Be safe, be seen! Incorporating 5 super bright LEDs, it is ideal as a tail light for bikes and joggers. Three different LED running patterns help get you noticed, and it water resistant. "Fright Night" Torch Air Powered Rocket Launcher and Pump Cat. ST-3041 So slimline it’s a bookmark! Holding a vocabulary of over 50,000 words, this dictionary’s vocabulary is about five times better than the average human. The flexible keypad fits neatly between pages, and it even Cat. XC-0185 has calculator $ .95 and alarm functions. 29 Electric Shock Reaction Game .95 Slimline 3 LED Book Light Bookmark Electronic Dictionary Neck Cooling System $ 39 9 Beat the heat! Keep cool and comfortable while wearing this device around your neck. A quiet motor drives a tiny fan to create an evaporative cooling system. Add a few drops of water to the neck cooler Cat. GH-1759 and away you go. Supplied with a $ .95 water bottle for evaporating. Cat. GH-1095 Multi-Function 5 LED Bike Light Super bright! It houses 5 LEDs in a water resistant enclosure – waterproof to 25m. It can operate steadily on, or flashing, and runs for up to 150hrs on 4 x AAA batteries. It measures 95(L) x 25(Dia) x 33(H)mm, and weighs 45g. Shave in the shower and save time! This 'anti-fog' mirror won't get steamed up, has a digital clock, and an AM/FM radio. Supplied with handy razor holder, suction cups, Cat. GH-1057 screen hook & hanger $ .95 cord. How quick are you? Wait for the light to change from red to green, then hit the button. If you are the last, you will receive a mild shock, but don’t jump the gun or you will get one too! Hands full? No worries! Just wave your hand, foot, or whatever you can, in front of the intelligent rubbish bin and the lid will open automatically! It will also close back up again, so you never need to Cat. GG-2315 touch it. $ .95 23L capacity. Compact and portable! While providing adequate light for reading, it is soft enough to not disturb your sleeping partner. It measures just 40(W) x 105(L) x 10(D)mm, and Cat. ST-3980 requires two $ .95 CR2450 batteries. 29 5Pc Bicycle Tool Set with Carry Bag Great for emergencies! It contains a hand pump, puncture repair kit, two-piece tyre lever, Allen keys and a stainless steel multi tool, all stored in a nylon pouch. Great for on the road, or general maintenance at home. Anti-Fog 5" Shaving Mirror with FM Radio 49 Cat. GT-3225 SAVE $5 24.95 $ Get a great massage on the go! It fits over most seats with the use of elastic straps, and the built in heater has three different heating levels. Three independent motors target the upper back, lower back, and thighs. Cat. GH-1753 Supplied with car and $ .95 mains adaptors. 49.95 Were $29.95 Cat. XC-0252 Remote Controlled Massage Seat Cover Pad with Built in Heater $ Great underwater fun! They have full manoeuvrability with forward, reverse, left and right, and a power dive function. Two types available: 27MHz Yellow GT-3044 40MHz Blue GT-3045 Intelligent Automatic Rubbish Bin 34 Cat. GT-3495 Was $29.95 Great for early risers! Don’t disturb your partner, just place the vibrating alarm clock under your pillow! It does have an audible option too, along with a bright backlit display, as well as current temperature and calendar info. Air Powered Jet Hawk Glider Launch it like a rocket and watch it soar like a hawk! Pump up the air powered launcher and send your Jet Hawk glider soaring 500 feet (150m) into the wild blue skies! It includes a safety feature to disable launching in horizontal or vertical positions. 610mm wing-span. Rechargeable 40 Channel UHF Transceiver Great range, great features! Since the outstanding success of our popular DC-1010 transceiver, it only seemed logical to refine the design, adding a few enhancements along the way. It is a lot more compact, measuring just 53(W) x 95(H) x 32(D)mm. It uses a small rechargeable battery pack, and is supplied with a dual charging cradle. You can still of course use AAA batteries as a backup. Four step scrambling is also provided for private communications, making this transceiver just plain fantastic! Supplied with one Cat. DC-1025 transceiver and a charging $ .95 cradle. 89 Cat. GT-3440 59.95 $ Addittional Transceivers Cat. DC-1028 $69.95 Extra Rechargeable Batteries Cat. DC-1029 $9.95 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au EXCALI B U R E LE CTRO N I C GAM I N G PRO D U CTS We have a great range of products designed in the USA. They are of excellent quality, just drop into your local store for a look! New York Times Electronic Crossword Puzzle Electronic Quiz Master Strain your brain! Over 2200 challenging questions covering 280 different topics. Questions are randomly selected, and it caters for up to 4 players. It is great fun, and is sure Cat. GE-4230 to keep you $ .95 entertained. Hours of fun! Over 1000 crosswords taken from the New York Times newspaper. They are sorted into three levels of difficulty, and is all operated through the touch screen interface. Cat. GE-4232 49 119.95 $ Electronic Bar Master Electronic Wine Expert 49.95 Stay safe and under the limit on the roads! This unit is very compact & features an integrated LCD to give you an actual readout of your blood alcohol content.. 7 Cat. QM-7294 69 $ .95 Alcohol Breath Tester with Readout Measure your BAC! Displays blood alcohol concentration between 0.00% & 0.05%. It provides a good result, but should not be relied upon to produce precise results. Cat. QM-7292 $ .95 Was $59.95 49 SAVE $10 Farting Salt n Pepper Shakers Every practical joker should have one! Cat. GH-1082 $ .95 Makes a great farting sound when the button is pressed. 9 19 .95 Cat. XC-0375 19.95 $ Oblique-Spheroid Haematite Magnets 12V Camping Shower A touch of luxury! Wash away the cares of the day no matter how far from civilisation you are! The camping shower allows you to take a shower wherever you are. Cat. YS-2800 Powered by your $ .95 vehicle’s 12V battery. 19 Bite Light Adaptor Simple but effective! This attachment fits over the end of your torch with a patented mouth piece to allow you to safely bite down on it to hold the torch in place. It also includes a neck lanyard. 7.95 $ Belt Pouch 199 INTERNET> www.jaycar.com.au 99.95 $ Cat. ST-3405 Fantastic price! This easy to use camera fits A digital video camera for in the palm of your hand! under $200! The recorded video can be transferred to a computer for editing, or simply viewed directly on any TV with AV inputs. Supplied with camera bag, cables and software. •3.1 mega pixel software resolution for stills. •1.5" colour LCD screen. •5 layer glass lens. •32MB internal memory SAVE Was $249 •SD/MMC expansion slot $50 Cat. QC-3230 •4x digital zoom $ .00 •Internal microphone and lots more! FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 "Ivan the Conqueror" Talking Chess Board Nite Ize accessories suit AA Maglites™ and small torches (not included). Mini Digital Video Camera Hand Held Farting Keyring 79 New “Nite Ize” Maglite™/Torch Accessories 14 19.95 $ $ How far is the next turn off? Automatically convert a map’s scale distance to real distance by rolling the small wheel along the desired route. It works with any map scale and displays in kilometres or miles. Great fun! Their name is quite a mouthful, but are actually quite simple. They are fun to play Cat. LM-1650 with, and are $ .95 supplied as a pair. A great gag for all occasions. They make a fart sound when tipped upside down. Great for parties! Cat. GH-1080 Cat. GH-1088 Digital Map Distance Calculator Pocket sized entertainment! You can play against the computer, or even use it as a ‘chess trainer’, with the computer suggesting the Cat. GT-3512 next best move. $ .95 Also play checkers! Cat. GT-3514 54.95 $ Keep the kids entertained! The Amazing Flygun is a safe, fun, and effective method of killing flies and mosquitoes. Launch the spring powered swatter at your target! It is safe, fun and really does work! Cat. YS-5545 KILLS $ .95 COCKROACHES TOO! Electronic Touch Screen Chess and Checkers Ordinary chess, evolved into an exciting battle! The intelligent computer can suggest moves, tell you which of your pieces are under attack, and more! Great sound effects add extra life to the game too. Cat. GT-3510 The Amazing Flygun! Alcohol Breath Tester with LCD Readout The new millennium’s whoopee cushion! Activated by a remote control, it has three realistic fart sounds. Great gaming options! Use the unit handheld on its own, or plug it into the unique Excalibur game board for a real electronic game. The computer can offer hints on moves, and more! $ .95 Remote Controlled Secret Farter 29.95 $ Cat. GE-4210 49 While providing a good indication of BAC, it should not be relied on for precise results, and you should never drink and drive. Cat. GT-3500 Two in One Chess Computer The electronic wine connoisseur! It contains over 10,000 reviews and ratings from wine experts, and you can save your own information too. It also teaches you wine basics including terminologies and descriptions. Mix every drink to perfection! Designed to look like a hipflask, this great gadget stores over 1000 drink recipes so you can mix up a storm. It also includes sample toasts for every occasion, and even Cat. GE-4212 bar jokes. $ Handheld Electronic Pool No need to go to the pub! You can choose from a game of 8 ball, or traditional pool. It uses a ‘virtual cue’ to give you control, with a pool table simulated on the screen. Great fun! Not your average belt pouch! Not only can you store your torch on your belt, but with real world use in mind it has a small pouch to carry two spare AA or AAA batteries. Made from strong Nylon. Cat. ST-3408 6.95 $ 7" Fibre Optic Adaptor Thin and flexible! Light only travels in straight lines, but you can make it bend with this Fibre Optic adaptor. A small attachment fits right over the head of your torch to give you a flexible light source for inspecting in tight places. 3mm diameter cable. Cat. ST-3410 14.95 $ 5 2.4GHz Wireless Colour LCD Receiver Roam while monitoring! Now you can take your surveillance monitor with you to watch the kids, or keep a lookout for potential thieves. It has a 65cm LCD and a speaker for audio. See our 2005 Cat. QC-3596 catalogue page 312 for $ .00 compatible cameras. 299 24VAC to 12VDC 300mA Power Adaptor Simple power distribution! Tap into your low-loss 24VAC professional wiring to power 12VDC cameras and equipment. Input voltage can Cat. MP-3069 range from 20-28VAC or $ .95 16-30VDC. 2 Channel Video Web Server with Email Alert Shed / Garage / Boat Alarm Very affordable! The garage or shed can often be neglected when it comes to security, but often there is valuable machinery and tools inside. This unit consists of a reed switch for the main door, and a PIR for general protection. Keyfob arm / disarm. Includes mains plugpack, 10m cable, and a battery backup option. Cat. LA-5400 $ .95 49 399 IP Addressable Camera 19 Pan/Tilt/Zoom CCD Colour Dome Camera with Pan / Tilt / Function Quad Output Video Distributor Remote surveillance? No worries! SAVE This internet addressable $100 camera features an integrated web server, so there is no need for a computer! Also has a local composite video output. Cat. QC-3390 Was $349 $ .00 No video loss! Suitable for small scale video distribution applications, you can view or record the video from any or all four outputs at any time. Includes mains Cat. QC-3439 plugpack. $ .95 99 249 Melcom 5 Sector Alarm Deal Versatile monitoring! This camera is integrated into a weatherproof dome housing, suitable for ceiling mounting. Just use the remote control to follow the action! It uses a 1/3" Panasonic colour Cat. QC-3497 CCD sensor to provide quality $ .00 420TV line resolution video. Secure your home or office NOW! Don’t delay any longer. Our great Melcom deal will get you all the parts you need and get you secure. See website for details. 499 Pan / Tilt / Zoom Dome Camera Fantastic price! Don’t pay thousands, this unit has 420TV line resolution, 350° panning angle, and 90° tilt range. It has 3x optical zoom with 4.2 – 12.7mm focal length. It has many features normally reserved for high priced units. Cat. QC-3500 $ .00 Remotely monitor your system! IP (Internet Protocol) surveillance has revolutionised the way we monitor and record in many surveillance situations. This web server can be connected to an existing setup, and transmits up to 12fps at 640 x 480 resolution. It has two video inputs and four alarm inputs to email you when one is triggered. Cat. QC-3394 $ .00 Cat. LA-5435 $ .00 369 16 Channel DVR with Audio and 120GB HDD The ultimate in digital surveillance recording! Don't be caught with difficulties trying to integrate multiplexers and recorders. This unit does it all in one, with seamless multiplexing and recording right down to one frame per second. See our website for a massive list of features! Was $1,599 SAVE $100 B&W Video Doorphone Cat. QV-3068 $ 1,499 See who’s at your door before you let them in! The 4" screen lets you see your visitors, & you can talk to them through the handset. Supplied with all mounting hardware and wiring. 799 New Pan / Tilt / Zoom Camera Controllers CCTV Mounting Brackets Expand the system! Buy an extra B&W Cat. QC-3602 Receiver QC-3603 with your video $ .00 doorphone for just $99. Save $80! 199 Colour Video Doorphone Small Professional Mounting Bracket Compact design! 60mm high and an optional 60mm extension post included. Standard 1/4" mount. Limited qty. Was $8.95 Cat. QC-3332 SAVE $ .95 $3 Top quality! The colour camera, and LCD Expandable performance! screen give you excellent clarity to When this unit is combined with the picture. Supplied with all the control receivers shown mounting hardware and wiring. below. You can control up to 100 Expand the system! Buy an extra colour Cat. QC-3606 External Camera Housing Mounting Bracket receivers, so it can provide the receiver QC-3607 with your video $ .00 Compact design! base to a very sophisticated and 8kg payload! doorphone for just $199. Save $150! elaborate surveillance setup. It also has support for Designed to mount our Indoor / control of focus and iris controls, and Outdoor camera housings. Cat. QC-3213 Motorcycle Alarm uses PELCO D control protocols for $ .95 210mm long, beige finish. Stop thieves dead in their tracks! reliability. See website for details. Limited qty. Cat. QC-3339 It has an ear piercing 120dB SAVE Was $29.95 $ .95 siren, and is triggered by a Pan / Tilt / Zoom Control Receivers $5 number of events. Very versatile! Supplied with electronic They interface with the controller Roof / Ceiling Mount Camera black box controller 90(W) x 32(H) x 75(D)mm, above to control Pan / Tilt / Zoom Housing Bracket two slimline key fob remote controls, cameras, as well as focus and iris Cat. LA-9020 30kg payload! controls when required. They can be Cat. QC-3212 wiring looms, red flashing LED warning $ .95 High strength when properly .95 light, and siren. used up to 2km away from the controller, $ anchored to a ceiling joist or and also have a relay output for concrete slab. 700mm total controlling lighting or locks etc. See website for details. Power Window Closers Let your alarm wind up your windows! length. Limited qty. Cat. QC-3338 SAVE $ .95 This unit interfaces with your car alarm to Was $34.95 $5 Cat. QC-3214 automatically wind up electric IP-65 Weatherproof $ .95 power windows when Receiver Microwave Sensor for Car Alarms you arm your alarm. It Extra security! can be used with Video / Power / Data Cable for Microwave sensors send out positive or negative Pan / Tilt / Zoom Cameras ultra high frequency radio triggered windows, and of course Long distance communication! waves, and detect the you do need to have power windows Cat. LR-8851 Send your video, power, and data reflections. It has an effective already fitted. Two models available: $ .95 over Cat5 UTP cable up to 300m range of 3m, sensitivity Two Door Version Cat. LR-8851 (colour) or 600m Cat. QC-3431 adjustment, and relay output. Cat. LA-9030 Cat. LR-8853 Four Door Version Cat. LR-8853 $ .95 $ .95 (B&W). $ .95 Pan / Tilt / Zoom Controller 5 399 249 24 149 69 29 189 49 39 6 59 29 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au NEW HARDCORE ELECTRONICS! Cat III Auto Ranging DMM Mini AC/DC Current Clamp Meter Double moulded housing! It features large digits, Cat III 600V certification, and is designed for the professional and serious enthusiast. •Capacitance. Cat. QM-1539 •Frequency. .95 •Relative measurement. $ Includes voltage detection! Rated at Cat II 600V, this clamp meter can measure AC or DC current up to 200A, and features an integrated non-contact voltage sensor. Supplied with a leather like belt pouch. 69 Charging dock supplied Cat. QM-1564 $ .95 99 Great for rework and SMD! The solder itself is 63% Tin, 37% Lead, with a 9.5% flux. It eliminates the need for clumsy resin core solder on fine circuits. 80g syringe. * Please ask sales staff for this product, as it is kept refrigerated. Cat. NS-3037 $ .95 29 Heavy Duty Chassis Mount Relays 20A Used in motors, transformers, heaters etc. •12V, 160 ohm coil. •20A <at> 220VAC / 30VDC. Cat. SY-4042 $ .95 5 30A Used in heavy duty applications like air conditioning, heating etc. •12V, 120 ohm coil. •Loads up to 7,500W. Cat. SY-4040 $ .95 •High inrush capability 65A, 10,000V. 7 Spirit Level with Laser & Tripod Handy to have! It is just like a regular spirit level, with the addition of a laser pointer in the end. Supplied with a handy tripod. Ltd qty. Was Cat. ST-3114 SAVE $ .95 $49.95 20(dia)mm x 2.5m 29 Fully automatic! They charge your batteries without fuss, switching to trickle charge when they reach capacity. Virtually any capacity can be charged, but the higher the capacity, the longer the charge. Was $39.95 Two types available: Both Types SAVE .95ea 6 Volt Cat. MB-3525 $ $15ea 12 Volt Cat. MB-3526 24 Mini Non-Contact Digital Thermometer Includes laser sighting! This mini digital thermometer can measure surface temperatures between -20°C and +270°C. It is small and lightweight, and very accurate. Cat. QM-7224 SAVE $ .95 Was $99.95 29 Quality Rechargeable Cordless Screwdriver FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au This is not a misprint! 22 Farad and 55 Farad super capacitors, specially engineered for high energy storage. Great for replacing bulkier secondary batteries in many circuits. See website for details. 22F Measures 12 x 25mm Cat. RE-6702 $ 55F Measures 18 x 40mm 12.95 19.95 Cat. RE-6704 $ Great price! This charger automatically discharges, then fast charges the cells. Suitable for AAA, AA, C, and D cells. Automatic trickle charge, mains powered. SAVE Was $49.95 $10 SAVE $4 Cat. MB-3500 $ .95 39 Pro Piezo Gas Soldering Tool Kit Great package! This kit contains a Portasol Pro Piezo Gas Soldering Iron, a range of tips, cleaning sponge and tray, as well as a durable storage case. Was $119 Cat. TS-1318 SAVE $ .00 SAVE $20 Top quality! This unit features a high torque motor, to drive screws harder and faster than those cheap units. Beware of inferior lower priced units - they do not have Cat. TD-2495 SAVE the same power as this $ .95 $8 unit. Was $19.95 11 Cat. NS-3032 $ .95 Universal Ni-Cd / Ni-MH Battery Charger with Discharge SAVE $6 Versatile! This charger will charge 6 and 12V SLA batteries at 1.8 amps. It includes short circuit and reverse polarity protection, as well as over Cat. MB-3523 current protection. $ .95 Was $49.95 $ 22F and 55F 2.5V Super Capacitors Mains Powerboards! Automatic 6/12V 1.8 Amp SLA Battery Charger 9 9.95 Cat. HP-1239 $39.95 Cat. HP-1237 33 4 Way with Filter / Surge & Overload Protection 23 12 Easy repairs! It is quick drying with a high silver content for superior corrosion resistance. 1.6mm trace width, 10 min drying time (typ). We have a MASSIVE new range of SMA leads, plugs, sockets and adaptors. See our new 2005 Catalogue for all the details. Was $27.95 Cat. MS-4031 $ .95 10uF Cat. RU-6602 20uF Cat. RU-6606 .95 each All Types $ Silver Conductive Pen 6 Way with Mains Filter 1 Amp SLA Battery Chargers 69 20(dia)mm x 10m 79 13 Cat. RU-6600 Cat. RU-6604 Cat. RU-6608 Tidy cables with ease! Unlike regular spiral binding, cables can be put in and out of the tubing with ease, using the included insertion shuttle. Made from flexible black plastic. 15(dia)mm x 2.5m Cat. HP-1235 $ .95 Simple and accurate! Useful for checking pH levels in water, fish tanks, swimming pools, and more! It is great in a chemical lab for testing and checking solutions, and the large LCD is easy to read. It has a range of 1 – 14pH, 0.1pH resolution, and +/-0.2pH accuracy. Cat. QM-1670 $ .95 Was $19.95 Cat. MS-4050 $ .95 6uF 12uF 30uF Dune Tube with Insertion Shuttle Non-contact! It measures up to 99,999RPM, and can be used to measure RPM or simply count revolutions. It has a large LCD display, laser pointer, and min/max recall. Great for the mechanics workshop Cat. QM-1448 or handyperson. $ .95 Digital PH Meter with LCD Solder Paste Syringe $30 Please note it is important to choose the correct value for the motor otherwise the starting torque of the motor will change. 69 39 $20 Motor Start Capacitors Now available! We have sourced a range of motor start capacitors necessary for starting single phase induction motors. They are suitable for motors operating at up to 400VAC. Digital Optical Tachometer Illuminated Multimeter Probes Not as extravagant as you think! They make light work of taking measurements in dark places and crowded cabinets. An LED in the tip is powered by an internal rechargeable battery and charger supplied. 800mm Cat. WT-5300 long. $ .95 This section is dedicated to what’s new for the Hardcore Enthusiast. $20 99 Super Pro Gas Soldering Took Kit Pro soldering! This kit contains a Portasol Super Pro Gas Soldering Iron, a range of tips, cleaning sponge and tray, as well as a durable storage Cat. TS-1328 case. $ .00 SAVE Was $149 $10 139 7 Cat. KC-5412 $ .95 39 Bass Extender Kit An extra octave of bass response! Ref: Silicon Chip April 2005. This project boosts the level of bass to counteract the frequency roll-off of your loudspeaker enclosures, effectively giving you an extra octave of bass response. Kit includes PCB KC-5411 and all electronic Cat. $ .95 components. 19 Micromitter Stereo FM Transmitter Kit Transmit quality audio to your FM stereo! Ref: Silicon Chip Dec 2002. Crystal locked to a preset frequency to eliminate frequency drift. Kit includes PCB, case, silk screened front panel, and all electronic components. Cat. KC-5341 $ .95 YOUR LOCAL JAYCAR STORE NEW SOUTH WALES Albury Ph (02) 6021 6788 Alexandria Ph (02) 9699 4699 Bankstown Ph (02) 9709 2822 Bondi Junction Ph (02) 9369 3899 Brookvale Ph (02) 9905 4130 Campbelltown Ph (02) 4620 7155 Erina Ph (02) 4365 3433 Hornsby Ph (02) 9476 6221 Newcastle Ph (02) 4965 3799 Parramatta Ph (02) 9683 3377 Penrith Ph (02) 4721 8337 Silverwater Ph (02) 9741 8557 St. Leonards Ph (02) 9439 4799 Sydney City Ph (02) 9267 1614 Taren Point Ph (02) 9531 7033 Wollongong Ph (02) 4226 7089 VICTORIA Coburg Ph (03) 9384 1811 Frankston Ph (03) 9781 4100 Geelong Ph (03) 5221 5800 Melbourne Ph (03) 9663 2030 Ringwood Ph (03) 9870 9053 Springvale Ph (03) 9547 1022 QUEENSLAND Aspley Ph (07) 3863 0099 Brisbane - Woolloongabba Ph (07) 3393 0777 Gold Coast - Mermaid Beach Ph (07) 5526 6722 Townsville Ph (07) 4772 5022 Underwood Ph (07) 3841 4888 AUSTRALIAN CAPITAL TERRITORY Canberra Ph (02) 6239 1801 TASMANIA Hobart Ph (03) 6272 9955 SOUTH AUSTRALIA Adelaide Ph (08) 8231 7355 Clovelly Park Ph (08) 8276 6901 WESTERN AUSTRALIA Perth Ph (08) 9328 8252 NORTHERN TERRITORY Darwin Ph (08) 8948 4043 NEW ZEALAND Hamilton Ph (07) 846 0177 Newmarket - Auckland Ph (09) 377 6421 Glenfield - Auckland Ph (09) 444 4628 Wellington Ph (04) 801 9005 Christchurch Ph (03) 379 1662 Freecall Orders Ph 0800 452 9227 8 Wireless Basketball Scoreboard Kit Dr Video Kit MkII Voice Recorder Kit Recording flexibility! Ref: SC May 2004. Record and playback up to 60 seconds of audio, all under the control of a PC or microcontroller. Variable sampling rate allows quality selection, and more. Kit supplied with PCB, voice recorder IC, and all electronic components. 49 High Energy Ignition Kit An even better video stabiliser! Ref: Silicon Chip June ‘04. Movie companies deliberately tamper with the video signal to restrict copying, but this robs you of the true high quality picture your system is capable of and you deserve. Get the picture you paid for and strip out these annoying signals from composite or S-video. Kit includes PCB, case, panels Cat. KC-5390 $ .95 and all electronic components. EXCLUSIVE TO JAYCAR! This kit enables you to make a full-sized electronic scoreboard, in particular for Basketball but also adaptable for netball and other games. Ref: Silicon Chip March/April/May 2005. It can be built for a fraction of the cost of commercial equivalents and has a completely wireless scoring console that can control one or multiple scoreboards. You can mount the scoreboards high up in a court and all you need is a convenient 240V power point. You can then control them from a table courtside with no messy wiring. It features Home/Away team scores 0 to 199, Game period, and Countdown time. The scoreboard measures 900 x 600mm. •The Jaycar kit comes complete with all pre-cut scoreboard woodwork, screen printed face, display filters, mounting plates, pre-programmed microcontroller, printed circuit boards, 2.4GHz transmitters and receivers, pre-punched control console with special piezo end-of-game/quarter sounder, and all electronic components to make one scoreboard. 99 V8 Sounding Doorbell Kit A must for car enthusiasts! Ref: Silicon Chip June ‘04. Be the envy of your mates as they hear the rumble when they press your doorbell. You may have seen commercially available units, but nothing like this. It sounds just like a V8, and has variable background noise for tappets and valves etc, for an even more realistic effect. 2 versions available: Available NOW Full V8 Doorbell Kit Supplied with PCBs, silk-screened and machined case, push button bell switch, speaker, hook-up wire, and all electronic components. Includes optional 120mm length of 100mm dia. pipe for that extra Cat. KC-5405 rumble! $ .95 Short Form V8 Doorbell Kit 79 Contains the working electronics only. Supplied with PCBs, and all electronic components. No case, speaker, or pushbutton etc Cat. KC-5406 supplied. $ .95 Less emissions! Ref: SC June ’98. A high energy 0.9ms spark burns fuel faster and more efficiently to give you more power! Includes PCB, Cat. KC-5247 case, and all electronic $ .95 components. 52 Regulated Voltage Adaptor Kit Very versatile! Ref: EA Aug ’97. Get a regulated 3 to 15VDC voltage at up to 1.5A from a car battery or ATX power supply. Includes PCB and components. 799 Additional Scoreboard Expand the possibilities! The control console can operate more than one scoreboard, so you can have one on each end of the court. Additional scoreboards contain everything Cat. KC-5409 $ .00 included in the original kit, without parts for the control console. 649 The SHORT CIRCUITS LEARNING SYSTEM The Short Circuits learning system is a great way to learn electronics. It is fun, informative, and you build great projects along the way. Here is just one from Short Circuits 3… Sound Activated Switch Kit Many applications! This project simply closes a relay when a loudenough sound is heard. It switches off again when the sound stops. Kit includes PCB, relay, electret mic, and all electronic components. Instructions are in the Short Circuits 3 book. Theremin Synthesiser Kit Cat. KA-1797 $ .95 6 Fuel Mixture Display Kit Is your car running right? Ref: SC Nov ’95. It gives an indication of fuel mixture via 10 LEDs. Kit includes PCB and all electronic components. 49 Cat. KC-5408 $ .00 14 Performance Electronics for Cars Book Over 160 pages! The Performance Electronics for Cars Book from Silicon Chip publications has chapters on modification and theory, as well as the 16 projects. Here is just one… Cat. BS-5080 $19.80 A must have! Ref: EA March ’91. Using just a handful of components, it can accurately time intervals to trip the relay. Includes PCB and all electronic components. PRICES VALID TO END MAY 2005 Cat. KA-1732 $ .95 18 12VDC Relay Card Kit Low current trigger! This kit will close the relay contacts with just 5mA as a trigger. Great for use with a kit using an LED trigger. Includes PCB and electronic Cat. KG-9142 components. $ .95 7 Dual 12V Battery Controller Kit Frequency Switch Kit Relay activation! Switch a relay on or off depending on the frequency of the input. This could be used as a shift-light, over speed warning & more. Kit includes PCB and all electronic components. 12 The "Flexitimer" Kit Far cheaper than commercial units! Ref: SC Aug ’00. The Theremin Synthesiser produces those familiar science fiction movie sound effects when you move your hand between the metal plate and antenna. It has an amazing range from shrieks to growls, and is not just entertaining. The Beach Boys used a Theremin in their classic hit "Good Vibrations" Kit Cat. KC-5295 supplied with PCB, silk $ .95 screened and machined case, metal plate,antenna, Also available speaker, all electronic pre-built & tested Cat. AM-4025 $99 components. 59 Cat. KC-5195 $ .95 Cat. KJ-8084 $ .95 Cat. KC-5378 $ .95 35 No more flat batteries! Ref: EA Feb ’96. It disconnects the auxiliary battery from the system when the engine is off, so you won’t run your primary flat. Kit includes PCB, case, and Cat. KA-1782 $ .95 all electronic components. 49 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au SILICON CHIP Order Form/Tax Invoice Silicon Chip Publications Pty Ltd ABN 49 003 205 490 www.siliconchip.com.au PRICE GUIDE: SUBSCRIPTIONS YOUR DETAILS (Note: all subscription prices include P&P). (Aust. prices include GST) Your Name________________________________________________________ (PLEASE PRINT) Organisation (if applicable)___________________________________________ Please state month to start. Australia: 1 yr ....................$A83 1 yr + binder .....................$A96.50 NZ (air): 1 yr .....................$A89 Overseas (air): 1 yr ...........$A135 2 yrs .....................$A160 2 yrs + 2 binders ..$A186 2 yrs .....................$A178 2 yrs .....................$A260 Address__________________________________________________________ PRICE GUIDE: OTHER PRODUCTS _________________________________________________________________ Postcode_____________ Daytime Phone No. ( )_____________________ Email address (if applicable) ___________________________________________ Method of Payment: (all prices include GST on Aust. orders) *SILICON CHIP BACK ISSUES in stock: 10% discount for 10 or more issues or photocopies. Australia: $A8.80 ea (including p&p). Overseas: $A10 each (including p&p by air). *ELECTRONICS AUSTRALIA: project photocopies, limited back issues. 10% discount for 10 or more issues or photocopies. Australia: $A8.80 each (including p&p). Overseas: $A10 ea (including p&p by air). o Cheque/Money Order o Bankcard o Visa Card o Master Card *BINDERS: BUY 5 or more and get them postage free. (Available in Aust. only): $A12.95 each plus $7 p&p per order. Card No. *ELECTRONICS PROJECTS FOR CARS, VOL.2: Aust. $A14.95; NZ/Asia/Pacific $A18.00 including p&p (air); elsewhere $21.50. (All prices include p&p). Card expiry date: Signature_____________________________ *PERFORMANCE ELECTRONICS FOR CARS: Aust. $A22.50; Overseas $A26.00. (Prices include p&p & GST where applicable). SUBSCRIBERS QUALIFY FOR 10% DISCOUNT ON ALL SILICON CHIP PRODUCTS* * except subscriptions/renewals Qty Item Price Item Description Subscribe to SILICON CHIP on-line at: www.siliconchip.com.au Both printed and on-line versions available Total TO PLACE YOUR ORDER siliconchip.com.au P&P if extra Total Price BUY MOR 10 OR ISSU E BACK ES A 1 0 & G ET DISC % OUN T $A Phone (02) 9979 5644 9am-5pm Mon-Fri Please have your credit card details ready OR Fax this form to (02) 9979 6503 with your credit card details 24 hours 7 days a week OR Mail this form, with your cheque/money order, to: Silicon Chip Publications Pty Ltd, PO Box 139, Collaroy, NSW, May 2005 61 Australia 2097 05-05 Part 2 – construction, testing and loading the software MIDI THEREMIN by John Clarke By now you are probably desperate to play a few compositions with the MIDI Theremin. But first you need to build it and install the software. Setting up the MIDI Theremin is quite detailed, so read carefully! F ollowing the circuit description of the MIDI Theremin in the first article last month, we shall now describe the construction and setting up procedure. Software will also need to be installed and to do this you’ll need to download some files from the ’net. Firstly, though, let’s start building the MIDI Theremin. Construction. The SILICON CHIP MIDI Theremin is constructed using two PC boards. The main PC board is coded 01204051 and measures 187 x 104mm, while the dis- play PC board is coded 01204052 and measures 142 x 99mm. The assembled PC boards are housed in a plastic box measuring 197 x 113 x 63mm. Begin construction by checking the PC boards for correct hole sizes and that there are no breaks in the copper or shorts between tracks or pads. Hole sizes for the corner mounts on the display PC board and for the LCD module should be 3mm diameter (~1/8”). Check the mounting holes for the external jack socket, the DC power socket, the DB9F serial connector and the MIDI output socket are all correct. Check also that the PC board to fits into the box neatly at the side pillar clips without bowing the box. If the box does bow out, the edges of the PC board will need to be filed off by a small amount so that it is a better fit. We assume that the Theremin is being built from the Jaycar kit (the only place you can get it!) – in this case all the holes in the box will have been milled out and a screen-printed front panel will be supplied. Display board Start assembly with the display PC board. Its overlay is shown in Fig.1. Insert the link first so you don’t forget Ludwig van, eat your heart out! You can become a composer with the MIDI Theremin and sequencer software! 62 Silicon Chip siliconchip.com.au Your friends will RAVE about your MIDI Theremin when they hear you playing like a pro! All you need is the MIDI Theremin and a MIDI Synthesiser – and if you own a PC, chances are you already have one of those! Here’s our MIDI Theremin working with the recommended “Rave” software on a laptop running Windows XP. Naturally, you’d normally separate the MIDI Theremin and laptop before use so that the volume plate wasn’t influenced. it. Mount the LCD module using a dual 7-pin header to connect from the LCD module to the PC board. Solder the pins on the topside of the LCD display and on the underside of the display PC board. The two opposite corner mounting holes on the LCD module are held down using two M3 x 10mm screws and M3 nuts, with some Nylon washers placed in-between the display PC board and LCD PC board. The trimpot (VR4) and the 10mF capacitor can now be mounted, noting that this capacitor should lie on its side to provide clearance when the display assembly is secured to the lid. Insert and solder in the 34-way right angle header plug. The switches can be inserted the wrong way if you aren’t careful. They are mounted as shown with the flat siliconchip.com.au side of the larger switches oriented to the side of the PC board. Switch S7 is mounted with the wider spaced pins mounted in the horizontal plane. The display board is now complete but before moving on to the main board, give it a close check for solder bridges, dry joints or incorrect component placement. Main board Begin assembly of the main PC board (Fig.2) by installing the links and resistors. Use the resistor colour code table or measure them with a digital multimeter to ensure the right resistor is in the right place. Next are the diodes – taking care to orient them as shown on the component overlay. Again watching orientation, IC1, IC3 and IC4 can be soldered directly to the PC board. IC2 is mounted using a socket – the socket can be soldered in now but don’t insert the IC yet. The capacitors and crystal can be mounted next. Again, the electrolytic capacitors must be oriented with the polarity shown. Now mount the transistors and PC stakes. There are two types of transformers, white-cored and black-cored. T1 and T3 are white-cored T2 and T4 are black-cored. Don’t mix them up! Each transformer has three pins on one side and two on the other, so you cannot insert them the wrong way. VR1 and VR2 can now be soldered in. REG1 mounts horizontally, with a heatsink sandwiched between it and the PC board. Bend its leads at the correct position so they fit into the May 2005 63 S9 S6 S3 SERIAL PORT TO PC GAMES PORT MIDI OUT 5-PIN DIN SOCKET 8 16 2 TO DISPLAY BOARD D3 D4 4148 4148 1 µF 100k REG1 7805 470Ω 1 µF 100nF IC2 PIC16F88 220Ω 1 1 100nF 68pF Q3 100k 100 µF 1 1 ANT 100nF 1 1 µF 33pF 33pF 15040210 IC4 MAX232 1 µF X1 8MHz D6 10 µF 220Ω 220Ω 220Ω 1 1 9 1 µF 5 4 EXT INPUT DC INPUT NI MERE HT IDI M IC3 6N139 T3 (WHITE) 470 µF 10 µF 4148 1 2 LED1 100Ω 13 14 S2 10 µF S1 S4 JAYCAR 2-LINE x 16 CHAR LCD MODULE S5 10k VR4 S8 S7 NI MERE HT IDI M TO MAIN BOARD 01204052 D5 100Ω 220k TP4 100nF T1 (WHITE) 64 Silicon Chip 390pF T2 560pF 100nF (BLACK) 2.2 µF TP GND 100nF VR1 2k 2.2 µF TP GND 1k TP3 2.2k 10k 220k 220k 100nF 1k 11 IC1 LM358 10 µF 2.2k Q2 TP1 560pF 680Ω TP2 10k Q1 100k D1 4148 220k 680Ω 100Ω V5+ 100Ω 100k 68pF PLATE Q4 100nF T4 (BLK) 4148 VR2 2k 100k 10k 10k 10k 2.2k 2.2k 2.2k 390pF D2 100nF siliconchip.com.au Fig.3 shows the 34-way IDC connections using the 34-way IDC wire and the two IDC connectors. Orient the tabs on the side of the connectors as shown (note the red striped wire is pin 1) and clip the back of the connector with the wire in LOCATING SPIGOT UNDERNEATH 1 1 34-WAY IDC CABLE 34-WAY IDC SOCKET SPLIT IN TWO 34-WAY IDC SOCKET DISPLAY BOARD CABLE 9 1 Fig. 3 (above): the 34-way IDC cable 16-PIN IDC DB15 MALE IDC PLUG SOCKET (IDC CABLE SIDE) which connects the 15-WAY (REAR VIEW) two PC boards. The IDC CABLE split down the middle isn’t essential – it just makes the cable easier to flex. Fig. 4 (right): the Games Port cable, with a DB15 male plug connecting to a 16-way IDC socket via NOT USED a 15-way cable. Note that pin 16 of the IDC GAMES PORT CABLE socket is not used. 15 Wiring LOCATING SPIGOT ON TOP 8 holes while allowing the tab to be secured to the PC board and heatsink using an M3 x 10mm screw and nut. Insert and solder in the upright 34-way IDC header taking care to orient it with the locating tab to the inside of the PC board. Similarly, solder in the MIDI out socket, the DB9 connector, the right angle 16-pin header, the DC socket and the 6.35mm jack socket. Note that when the jack socket is oriented with the input towards the top, the switching contacts should be to the left and the wiping contacts for the jack on the right. If they are the other way around, remove the contacts from the plastic moulding and swap them around. LED1 is mounted with the longer (anode) lead to the left and as high on its legs as possible – leave just a millimetre of the shorter (cathode) lead under the PC board for soldering. The LED is later bent over to fit into the hole in the side of the box. When complete, place the PC board in the box and clip the edges into the integral box side attachments. Attach the nut to the 6.35mm jack socket. The display PC board can now be secured to the case lid using the 5 x 10mm tapped standoffs and M3 x 6mm screws. Connect short lengths of wire to the M3 and M4 eyelets. Now attach the hand plate to the side of the box using M3 x 10mm screws and nuts remembering to place the M3 eyelet onto the screw closest to T1. The antenna is secured with a nut once the M4 eyelet is placed on. These two component overlays and photographs should help you assemble the two PC boards. Fig.1, (opposite top) is the display board while opposite and below is Fig.2, the main board. The two boards connect together via the IDC cable above. siliconchip.com.au May 2005 65 place. Use a vyce to press the parts together. ‑To allow more flexibility of the cable, we split the IDC cable lengthwise into two sections by opening it up around the centre (you don’t have to be too exact!). Make the connection between the main PC board and display PC board Games port wiring (Fig.4) is similar to the 34-way wiring except that we use 15-way cable. This is secured to the DB15 connector using a vyce as before. Only 15 of the 16 pins of the IDC socket are used – locate the 15-way IDC cable by not placing the wire onto the left most pin (pin 16), as shown. Wiring can now be completed for the last potentiometer (VR3) and to the hand plate eyelet and antenna eyelet. These last two wires should be made as short as possible with just enough length to connect from the PC stakes on the PC board to the securing points for the plate and antenna. The wires for the power switch (S10) MIDI INVALID MIDI OUT SERIAL PORT are made using crimp connectors for the switch connections and soldered to the PC stakes on the PC board. Once again, give the finished PC board a good visual check for solder bridges, dry joints (or non-soldered joints – it’s easy to miss one or two!) and misplaced or wrongly oriented polarised components. Testing The Theremin is now ready for testing. Make sure IC2 is not in its POWER SWITCH S10 EXTERNAL PITCH ANTENNA (M4 EYELET) 9V DC IN 8 16 1 9 2 TO GAMES PORT 5 4 15040210 34-WAY IDC CABLE 1 1 NI MERE HT IDI M 1 1 V5+ 1 (STRIPE) VR3 VR2 DISPLAY BOARD (IDC CABLE SLIT AND TWISTED) MAIN BOARD VOLUME PLATE (M3 EYELET) POT VR3 (STRIPE) 13 JAYCAR 14 34-WAY IDC CABLE 1 25040210 2 NIMEREHT IDIM 66 Silicon Chip Fig.5: the interconnecting wiring is delightfully simple – most is taken care of via the 34-way IDC cable. The only other external wiring is to the power switch, potentiometer, the antenna and hand plate. siliconchip.com.au socket. Plug in the plugpack into the DC socket. Connect your multimeter common (black) lead to one of the TP GND PC stakes and connect the positive (red) lead of the multimeter to the input of REG1 (left pin). Switch on the plugpack at the mains and switch on S10. If you get a reading of about 9V, good. If the reading is zero, check that the DC plug for the plugpack is inserted correctly into the two pronged plugpack lead connection. You can rotate this connection by 180° – then check the voltage at the input of REG1 again to ensure you now get the 9V reading. Measure the output of REG1 (right terminal) for +5V. If this is not +5V (or very close) check the PC board for a short circuit. You should also be able to measure 5V between pins 5 and 14 of the IC2 socket and about 9V between pins 4 and 8 of IC1. On IC4 check for 5V at pin 16, -9V at pin 6 and 9V at pin 2. These 9V readings may be anywhere up to 9.6V. If the voltages are OK, turn the power off, wait a short time – say five seconds – and install IC2 into its socket, the right way around! Apply power and check the display lights up and shows characters. If you Here’s the display board installed on the case lid. Here you can also see the divided 34-way IDC cable – it’s essential to do this because the cable is twisted. cannot see anything on the display adjust VR4. This trimpot needs to be adjusted to give the best display contrast. Check operation of all switches by going through the switch functions described last month. Setting up Test points have been included to help make setting up a little easier. Custom-made Lithium Ion, NiCd and NiMH battery packs These provide connection points for your multimeter so measurements can be taken as you make adjustments. You will need either (preferably) a plastic alignment tool with a 3.5-4mm wide flat blade, or a screwdriver with the same type of blade, to adjust the slugs in the IF transformers. The plastic tool should not affect your readings: However, if using a metal screwdriver, you may need to NiCd/NiMH Smart Chargers www.batterybook.com (08) 9240 5000 Li-Ion Smart Chargers 2400mAh NiMH AA cells siliconchip.com.au High-quality single cell chargers with independent channels. Charge any combination of NiCd & NiMH AA and AAA cells Ask for a free copy of the Battery Book catalogue or visit www.batterybook.com May 2005 67 Parts List – MIDI Theremin 1 PC board, coded 01204051, 187 x 104mm 1 PC board, coded 01204052, 142 x 99mm 1 plastic box, 197 x 113 x 63mm (UB2) 1 antenna, 170mm long 1 hand plate, 80 x 70 x 1mm aluminium 1 2-line 16-character LCD module (backlit) 1 mini rocker switch (S10) 1 PC-mount 6.35mm switched jack socket 1 5-pin PC-mount DIN socket 1 DB15 IDC male plug 1 DB9 PC-mount right angle female connector 1 34-pin IDC header 1 34-pin right angle IDC header 1 16-pin right angle IDC header 2 34-pin IDC line sockets 1 16-pin IDC socket 1 7-way DIL header 1 9V 150mA DC plugpack 1 PC mount DC power socket 8 SPST PCB mount snap action switches (S1-S6, S8,S9) 1 SPST micro tactile switch (S7) 1 5kW 16mm linear potentiometer (VR3) 1 knob to suit VR3 1 18 pin IC socket 1 heatsink 19 x 19 x 10mm 1 8MHz crystal (X1) 5 10mm tapped spacers 10 M3 x 6mm screws 5 M3 nuts 5 M3 x 10mm screws 6 3mm ID Nylon washers 1 3mm crimp eyelet 1 4mm crimp eyelet 2 crimp spade female connectors for switch 2 coils, second IF, white, (T1,T3) 2 coils, third IF, black (T2,T4) 1 serial DB9 cable (male to female) adjust the slugs in small steps taking the screwdriver away from the transformer slug to take the readings. Also take care if using a metal screwdriver that you do not crack the brittle ferrite transformer cores. Do not force the slug past its end stops. A small 2.5-3mm flat bladed screwdriver will also be required for adjusting trimpots VR1 and VR2. Connect your multimeter between 68 Silicon Chip 1 30mm length of 0.8mm tinned copper wire 1 220mm length of 34-way IDC wire 1 2m length of 15-way IDC wire 1 100mm length of black hookup wire 1 100mm length of green hookup wire 1 150mm length of yellow hookup wire 11 PC stakes Semiconductors 1 LM358 dual op amp (IC1) 1 PIC16F88 programmed with midith02.hex (IC2) 1 6N138 optocoupler (IC3) 1 MAX232 RS232 receiver/driver (IC4) 1 7805 three-terminal 5V regulator (REG1) 2 BC547 NPN transistors (Q2,Q4) 2 2N5484 JFETs (Q1,Q3) 1 1N4004 1A diode (D6) 5 1N4148 switching diodes (D1-D5) 1 5mm red LED (LED1) Capacitors 1 470mF 16VW electrolytic 2 100mF 16VW electrolytic 5 10mF 16VW electrolytic 2 2.2mF 16VW electrolytic 5 1mF ceramic 4 100nF ceramic 4 100nF MKT polyester 2 560pF ceramic 2 390pF ceramic 2 68pFceramic 2 33pF ceramic Resistors 1/4W 1% 4 220kW 5 100kW 5 10kW 5 2.2kW 2 1kW 2 680W 1 470W 4 220W 4 100W 2 2kW top turn multiturn trimpots (VR1,VR2) 1 10k horizontal trimpot (VR4) one of the TP GND terminals and TP1. Using the alignment tool, adjust T2 for a reading of about 0.9V while your hand is away from the hand plate. Now move your hand close to the hand plate. The voltage should fall just slightly – by about 0.06V or so. If the voltage goes up instead, then the core will need readjusting. Take your hand away from the hand plate and turn the core anticlockwise, so that you see the voltage rise to a maximum and then fall again. Stop turning when the voltage reaches 0.9V again. Note that the rise and fall in voltage may not happen before you run out of adjustment (where the slug cannot be wound anticlockwise any more). In this case, turn the core in T1 clockwise by one turn and the T2 core clockwise by more than one turn, then adjust anticlockwise again, stopping at the point where the voltage falls to 0.9V. Now transfer the multimeter lead to TP2 and adjust VR1 for a reading of about 6V making sure your hand is away from the hand plate. Now move your hand close to the hand plate. The voltage should go down to near 0V. This adjustment is critical and can change when the lid of the Theremin is placed on the box. The adjustment is affected by lead dress inside the box and so some readjustment may be necessary later to have the hand plate operation work over a satisfactory range of hand movement. Adjustment of the antenna circuit is the same as for the hand plate. In this case place the meter between TP GND and TP3 and adjust T4 for the 0.9V reading. Readjust T3 clockwise if you cannot find the position for T4 where the voltage falls from 0.9V when your hand is brought near to the antenna. Adjust VR2 with the multimeter re-attached to TP4 for a reading of about 6V with the hand away from the antenna. To make the final adjustment, place the MIDI Theremin lid on and select the Note display. Observe the volume and note values. The volume can be controlled from 500 when the hand is away from the plate down to 0 with your hand close to the plate. If the volume shows less than 500 with the hand away from the plate, readjust VR1 (you’ll need to take off the lid again!) for the 500 reading. Adjust VR1 so that the volume starts to fall from 500 when your hand is around 100mm from the plate. Similarly, when adjusting VR2, set this so that the top note begins to change at about the 100mm mark as your hand is brought closer and closer to the antenna. The top note will be C6 for the normal range setting and G8 in the wide setting. For really precise tuning, adjust VR2 with the antenna extended by about 10mm. Then when the lid is closed siliconchip.com.au Capacitor Codes Value IEC Code EIA Code 1mF 1m0 105 100nF (0.1mF) 100n 104 560pF 560p 561 390pF 390p 391 68pF 68p 68 33pF 33p 33 on the Theremin, you can shorten or lengthen the antenna slightly to obtain the best results from the antenna control without having to open the lid. External control If an external foot control is required instead of the auxiliary potentiometer, a suitable design was published as part of the Waa-Waa Pedal in the September 1998 issue of SILICON CHIP. Naturally, you won’t require anything but the pedal itself; however full pedal constructional details are given in that article. Use dual-cored, shielded cable for the interconnection, with the earth braid connecting to the common terminal on the stereo jack plug and the earth end of the potentiometer. Also note that the pot used in the MIDI Theremin is a 5kW linear, not 10kW to 50kW as used in the Waa-Waa Pedal. A socket could be installed on the footswitch as shown in the original design or you could use a fixed lead from the foot switch to the jackplug. This later alternative is the wiring shown for the potentiometer in Fig.6. You can obtain a back issue of September 1998 or a copy of the article for $8.80 from SILICON CHIP. Software As mentioned last month, if you want to use the MIDI Theremin with a computer, you will need to install sequencer software. The software provides the means to send a MIDI signal to the computer and to drive the sound card’s synthesiser. There are many sequencers available on‑the market including Cakewalk, Propellerhead’s Reason, the ComputerMuzys CM Studio and Rave. We have tested the MIDI Theremin on the last three. By far, the easiest-tooperate sequencer is Rave. You can use other sequencer software if you wish, however, we recommend using Rave first unless you are already well versed in using them. siliconchip.com.au POT TIP SLEEVE RING Many sequencers are a little daunting when you start them up, due to their hugely complex control features. The Rave sequencer is ideal for firsttime users as it is easy to use and has sufficient features for use with the MIDI Theremin. In fact, we believe most people will be completely satisfied with this sequencer. If you plan to use a different sequencer, it must be able to accept incoming MIDI signals and direct them to the sound card’s synthesiser. Some sequencers do not do this and only send the MIDI signal back out through the MIDI output on the computer. This means that the computer’s synthesiser will not generate any sound. The Propellerhead “Reason” software is available on the net as a demo version with a “no-save” feature and an after-20-minute automatic shutdown. It must be purchased if you want to continue to use it (www. propellerhead.se). The Computer Muzys CM Studio is usually available on the CD supplied with “Computer Music” magazine from Future Publishing in the UK. Check it out at your newsagent. This software requires a minimum 500MHz PC or MAC (www.comptermusic. co.uk). RAVE for Windows is available as a free download from the ’net (www. files1.sonicspot.com/rave/rave.zip). This software (or another sequencer program) is the only software you will need to install if you are connecting to the computer using the sound card input via the games port. In this case make sure the Port settings on the MIDI Theremin are <DRIVE> VIA MIDI OUT & GAMES PORT. What, no games port? If you do not have a games port input, then you can connect via a serial port, or failing this using a USB port via a USB adaptor. USB connection is the most finicky way of operating the MIDI Theremin and if you have a serial port it is recommended to use it rather than via USB. If you are not convinced that the 6.5mm STEREO PLUG RING SLEEVE TIP Fig.6: if you want an external control (including a foot pedal) here’s how to wire the pot to the 6.5mm stereo plug. serial connection is best, read the notes concerning USB operation in the section describing installing the USB driver. For USB use, there are two options. Firstly, you can use a Serial-to-USB converter and this is used in conjunction with the MIDI serial driver. Software to setup a USB to virtual serial port driver will be required and this is supplied with the Serial to USB converter. (See overleaf for the USB installation). For this option the Port settings on the MIDI Theremin will need to be set to <DRIVE> VIA SERIAL PORT ONLY. Alternatively, if you use a MIDI-toUSB converter (available from music shops) then you only need to install the sequencer software and the MIDIto-USB driver. In this case make sure the Port settings on the MIDI Theremin are <DRIVE> VIA MIDI OUT & GAMES PORT. The MIDI-to-USB converter connects directly into the MIDI outlet on the Theremin. Software drivers for this converter should be supplied with it. We will only describe setting up the Serial-to-USB converter since this is the cheapest option. You’ll find the complete setup procedure in the panels on the next four pages. Where do you get the kit? This project was sponsored by Jaycar Electronics, who hold the copyright on the design, PC board layouts, etc. Kits are available from all Jaycar Electronics stores and most resellers. The complete kit of parts (KC 5410) as described here, including hand plate, antenna, case, silk-screened front panel and a mini stand, sells for $159.00 A suitable power supply is the Jaycar M-3003 selling for $13.95 For more information, refer to Jaycar’s website: www.jaycar.com.au May 2005 69 Checking your computer settings and inst When installing any programs or drivers, you need to be logged on to your computer as an administrator. Before installing the sequencer software, it is best to check the settings in your computer to make sure that sound card is set up correctly for MIDI. For Windows XP select Start/control panel. Then switch to ‘classic view’ if it is set in the ‘category view’ mode. Now select sounds, speech and audio devices/audio/ midi music playback. In the MIDI music playback, select an MPU-401 compatible synthesiser (eg Microsoft GS Wavetable SW synth) Also make sure volume is up for the synthesizer. Do this by selecting volume in the MIDI music playback box and checking settings for the SW Synth. This is similar for Windows 98. In this case select Start/settings/control panel/ multimedia/. In the multimedia properties select MIDI and an MPU-401 compatible synthesizer for internal synthesis. (eg. ESFM Synthesis (220)) Also in Start/programs/accessories/entertainment/volume control. Check that volume control level for synthesizer is up. Driver signing Later versions of Windows include driver signing. You need to check that this is not set to block programs from being installed. To check the settings in Windows XP, select Start/control panel/hardware/driver signing. Click on the Warn only button, if not already selected. The zip file is 647k bytes and must be unzipped before use. If using Windows 3.1, you’ll need to use PKunzip to extract the zipped files. The software was written to run on Windows 3.1. We have tested it on Windows 98, Windows ME and Windows XP. The only problem we have experienced during installation is where error messages are shown because the DOS help file is not installed on the computer. This occurs because the software was written for Windows 3.1 and the operating system relied on having DOS installed. Once the Rave software is installed, the error messages do not affect the operation of the RAVE sequencer. Download the rave.zip file from the location shown above and save the file to a directory (or folder) called C:\rave (or similar). When the file is unzipped, install the software using setup.exe. During installation the computer may ask if you want to run this software with an unknown publisher. In this case click on the run tab. As mentioned, if you are using a current version of Windows that does not include DOS; there will be an error message saying could not open the file c:\dos\doshelp.hlp. Click on ignore. A similar DOS shell error will also be shown. Again, click on ignore. Click on close after the general protection fault error is shown. When installation is complete, use Windows explorer or file manager go to the folder c:\rave. Single click onto rave.exe (c:\rave\ rave.exe) then to “File” and then select create shortcut from the list of options. Drag the shortcut to the desktop (this does not apply with Windows 3.1). Also copy the midiout.drv file (found in the to the c:\rave folder to the c:\windows\system folder. If you wish to uninstall RAVE, locate the c:\rave folder and delete it and all files it contains. Delete the desktop shortcut and remove the midiout.drv file from the c:\ windows\system folder. Serial or USB operation If you are connecting to the serial or USB port, you will need to install the required drivers now. Details are in the separate serial port driver section and Serial-to-USB section. Don’t forget that if you are using the serial- to-USB converter, the MIDI serial driver will also be required. For a MIDI-to-USB driver install as per the instructions supplied with it. Running Rave To start up Rave, double click the Rave shortcut on the desktop. A Rave copyright box will appear. Click on the ok button. Setting up RAVE Select the Options and the “midi thru” box. Rave Installation The sequencer program is available from www.files1.sonicspot.com/rave/rave.zip 70 Silicon Chip siliconchip.com.au talling the MIDI Theremin software This will bring up a tick against the MIDI Thru. The sound card synthesizer will not produce any sounds unless this box is ticked. Check that the Options/Metronome/Bars Count In is set to at least 1 (if this is set to zero you will not be able to record) . Check in the Options/Output Assignments. The settings should show the MIDI Mapper. Recording To record, select File/new. Save as ‘yourfilename’.blk. Click onto the REC(ord) button to begin recording. The tape transport position marker will start to count up after a second or so and you are now recording. The stop, fast wind and stop buttons operate the same as any tape or video recorder. So you can stop, rewind and play the composition. Saving the recorded composition is done by selecting File/save. Once you have saved a track you can multitrack record if you want to. This lays down another recording alongside the original recording. So you can playback with more than one track, as though there is more than one Theremin playing, or you can record another instrument such as a keyboard to accompany the Theremin. To multi-track record Left click the mouse pointer in the track name block (eg, where silicon chip 2 is positioned) to select second track. These are initially set with an unnamed label but they can be renamed by right clicking the mouse pointer on the word and use the backspace to delete the word. Rewrite your own required filename. The selected track can then be recorded as a separate track with the original recording. Up to 32 tracks can be recorded. In the right hand blocks, there is the option to change the patch (instrument), the volume, pan and quantisation. Play around with these options to understand the changes they make. Playing the MIDI Theremin You are finally ready to play the Theremin! Connect up the serial, USB or games port lead between the MIDI Theremin and the computer. Switch on the MIDI Theremin and check that you can play the instrument and hear it through the sound card output using headphones or loudspeakers. If you cannot hear anything, first make sure the volume is turned up on the computer and that the sound works on other mediums such as the CD player. If the CD player works and sound still cannot be heard with the Theremin, double check the MIDI Thru is ticked in the RAVE/ Options settings and that you have selected the correct port in the settings menu on the MIDI Theremin. Also check the settings as mentioned in the MIDI serial driver section and the Serialto-USB sections. siliconchip.com.au The recorded composition can also be shown in music format. Select Edit/Score editor to show the traditional five line (musical staff) format of the recorded composition. Particular notes can be selected with the mouse pointer and its value (eg, B2 for note B in the second octave) is the same as shown on the MIDI Theremin. Note that extremely complex compositions using the Pitch Glide control may cause the software to overload when selecting the Score editor. This is a basic rundown on how to use the software. It is sufficient to enable you to play and record plus do some multitracking if required. From here on, you’re on your own. The only way you will discover the full potential of the MIDI Theremin is to play with it. Enjoy! Installing the serial driver The serial driver is commercial software written by Yamaha Corporation for their MIDI musical instruments. It supports Windows 95, 98, ME, NT, 2000 and XP. The driver automatically detects your operating system and installs one of two versions best suited for your computer. Both files are contained in a file called cbxdrv201w.zip. This is a 971Kb file and is designed for use with COM1 or COM3 port on the computer. When using with a serial port connection, make sure that you have a free COM1 or COM3 port on your computer before installing the driver. In some cases you may be using the COM ports for a serial mouse and/or external modem. You may have to free up one of these ports so you can use the MIDI Theremin with this serial port driver. In general, the Modem connection could be used or if you only have one serial port, use this and connect your serial mouse to a USB port using the commonly available USB-to-serial converters available (one may well have come with your mouse) or buy a USB mouse – they are very cheap these days. When used in conjunction with a USBto-serial converter, the COM port numbers apply to the virtual serial port created with the USB-to-serial driver software (see its installation in the separate section). The Yamaha serial driver file can be obtained from: www.yamaha.co.uk/xg/ download/tools/cbxdrv201w.zip Save the file to a directory (or folder) called c:\midicbx (or similar) and unzip it. A readme file will be unzipped to c:\midicbx\ cbxdrv201w\setupdir\009\readme.txt and this describes in detail how to set up the driver for the various Windows operating system versions. Basically, all you do is double click on the setup.exe (found in the setup folder) file and follow the prompts. When the “select COM ports” dialog shows, check COM1 or COM3. The selection is dependent on how many serial ports you have and which one you are going to use for May 2005 71 the MIDI Theremin connection. If you are connecting via USB, select a COM port that does not correspond to a serial port that is already installed. classic view, then select sounds, speech and audio devices/audio/midi music playback. In the MIDI music playback, select the down arrow to check if YAMAHA CBX A Driver is installed. Do not select this driver, we are just looking to see if it is there, so keep the original SW Synth setting. Once installed, you can change settings and disable the driver without uninstalling it. To do this select Start/Control Panel and double click on the Yamaha CBX driver Icon. Click on the Next button and the MIDI output ports dialog will be shown. Select the ‘Use single MIDI output port’. When you double click on the YAMAHA CBX Driver Icon, the CBX Driver Setup box will be displayed. You can select the COM port (again) and enable or disable the driver. The greyed out selections cannot be used. Click on Next and that completes the installation. The following dialog box will be displayed. It reminds the user to select the PC-2 position on the Yamaha MIDI units ‘To Host’ select switch. For our MIDI Theremin it reminds us to select the serial port setting on the Theremin. Restart the computer to finalise the installation. (Yamcbxdv.bmp) Correct installation can be seen in the ‘sounds and audio devices’ properties box. For Windows XP select Start/Control Panel in When using this driver with RAVE you can see if it is connected correctly by selecting Options/Synchronisation. If correct the Yamaha CBX Driver will be displayed in the Synchronisation input port box. USB Operation (via serial to USB converter) When connecting the MIDI Theremin using a USB port, you will need a USB-to-serial (DB9) converter, which converts the serial signal from the MIDI Theremin’s serial port output to a USB signal. A suitable device is available from Jaycar Electronics, cat number XC-4835. The software supplied with this converter then produces a virtual serial port on the computer. This virtual port can be read by the Yamaha MIDI serial port driver that is already installed. Both the virtual serial port and the MIDI serial port driver must be set to the same COM port. Note that if you have a serial port on your computer, it is preferable not to select the same COM port number for the virtual port. To install the USB-to-serial converter and the software, plug in the USB unit to a USB port on the computer. The computer will alert that new hardware has been installed. In Windows XP, the Add New Hardware Wizard will start up and assist in setting up the USB converter. When prompted, select insert the CD ROM disk into the computers CD drive and select the ‘USB to serial cable’\ WN DRIVER\98-2009-2K20021 folder. Click next to install. If you have problems with this method, disconnect the USB to serial converter, wait a short time (say ten seconds) and reconnect. Wait until the new hardware has been detected and the ‘add new hardware’ wizard opens. Select the ‘install from a list or specific location’, then click next. Select ‘Don’t search I will choose the driver to install’ and click next. Click on ‘Have disk’ then browse to the CD ROM\WN Driver\982009-2K20021\serspl.inf. Click on open, ok and next. A warning may appear to say that the software is not logo tested for compatibility with windows. Click on the ‘continue anyway’ button. Uninstalling or reinstalling Removing the YAMAHA CBX Driver Navigate to the c:\midicbx folder and double-click the setup.exe. The Setup dialog will appear. Follow the prompts to remove the driver. Restart the computer to complete the removal. 72 Silicon Chip Make sure the USB-to-serial driver is plugged into the computer. Select Start/ Control Panel/system. In the system properties select hardware/device manager/ ports (COM & LPT). Select the ‘Prolific USBserial-bridge’. Double click on this then select Driver/uninstall and ok when it prompts you to uninstall. You can reinstall using this method by selecting the update driver button and direct to the folder on the CD ROM as before. To change the COM port setting on the USB to serial converter, select Start/Control siliconchip.com.au Panel/system. In the system properties select hardware/device manager/ ports (COM & LPT). Select the ‘Prolific USBserial-bridge’. Double click on this then select port settings/advanced. Select the COM port number from the drop down menu. Note that the port number must match the port number selected for the Yamaha MIDI serial port driver. You can only select the ports that the Yamaha MIDI serial port driver allows. In our case as shown in the Yamaha CBX driver setup this is COM1 or COM3. Note that it is unnecessary to alter the port settings apart from the COM number as the USB to serial driver sends at its maximum rate regardless of the port settings. This is true even though the serial signal from the MIDI Theremin is sent at the 38400baud rate and the rate is set to a different value in the settings. Notes on the USB connection 1. You can connect the USB-to-serial converter to the MIDI Theremin in one of two ways. First, you can use a DB9 extension cable. The cable connects to the MIDI Theremin serial outlet and the socket end connects to the USB-to-serial converter. Plug the USB end into the computer. Alternatively, if you only require a short connection, the USB converter can be directly connected to the MIDI Theremin serial outlet. In this case the retaining screws on the MIDI Theremin serial outlet will need to be removed and inserted from the inside of the box in order to secure the USB converter unit in place. A 1.8m USB 2.0 A to A extension cable can be used to make the computer connection. siliconchip.com.au 2. If you plug the USB-to-serial converter into a different USB port on the computer, you will need to install the driver for that USB port. It’s much better to always plug into the original USB port where the driver was installed (maybe label the USB input?). 3. Avoid plugging the USB-to-serial unit into the computer while the MIDI Theremin is switched on or the computer may sometimes decide the device is a mouse or similar human interface device rather than the USB converter. If this happens, you will need to reinstall the USB to serial converter software as detailed above or click onto the driver ‘rollback’ button instead of the ‘reinstall button’. This last option reverts the driver to the previous USB-to-serial driver and installation is quicker (and you do not need to find the CD ROM!). 4. If you see this panel when starting Rave, it means that the MIDI Theremin will not (at present) work with the USB converter. The panel indicates that the virtual port data is corrupted. It could be that the Serial-to-USB Converter is not connected, or simply that the USB converter has to be reset. Alternatively, the COM ports selected for the Yamaha serial driver and the USB to serial driver may not be the same one. In the first two cases, click on the ‘no’ button and then the OK on the copyright panel when Rave starts. Exit from Rave by clicking on the top right hand X button (or File\exit). Unplug the USB connection and wait for the disconnect confirmation, then reconnect it and start Rave again. The wave device-warning panel should not appear this time. 5. If you switch off the MIDI Theremin while you are within Rave, then the only way to have the MIDI Theremin play again is to exit from Rave and then restart Rave. Similarly in ComputerMuzys you may receive this error when starting. Muzyserr.bmp In this case exit from the program, disconnect the USB connection and reconnect it. Then restart the program. The Computer Muzys MIDI port is set using the System/ MIDI Hardware selection and the MIDI Hardware set-up panel will be shown. The reason? Following is a screen grab showing the Reason Sequencer demo version. Note the complexity compared to the Rave sequencer. The MIDI port is selected by clicking onto Edit then selecting preferences. Use the down button to select the page that shows MIDI. The port shows the Yamaha CBX driver is selected and the tick indicates that it is working. (reason.bmp) Apple Macintosh Computers Although we have not tried it, Mac users should be able to use the MIDI Theremin by using a Mac version MIDI sequencer. For example the ComputerMuzys CM studio and Reason 2.5 are available for the Mac. There are at least two options when making the connections between the MIDI Theremin and a Mac. You may need to visit a music shop and purchase a cable or converter. The simplest option is to use a MIDI-to-printer-port cable. The Mac already has MIDI drivers installed for this connection but it is only useful if you have a printer port. For USB connection you will require a USB-to-MIDI converter such as the Yamaha UX96. This converts from the MIDI outlet on the MIDI Theremin to USB format. The driver supplied with the converter will need to be installed. Alternatively, some Mac laptops supply a USB-to-serial converter and you may be able to use this when connected to the serial port on the MIDI Theremin. A music shop salesperson well versed in MIDI should be able to supply you with the necessary information and hardware SC required. May 2005 73 CIRCUIT NOTEBOOK Interesting circuit ideas which we have checked but not built and tested. Contributions from readers are welcome and will be paid for at standard rates. Automatic bathroom exhaust fan This circuit starts a bathroom exhaust fan automatically when the shower’s hot water is used. It also includes a push-button switch to allow the fan to be stopped or started at will. The fan runs for a predefined period (nominally four minutes) with reminder beeps at the 2 and 4-minute marks as a water saving initiative. NTC thermistor TH1 senses water temperature, with an increase in temperature causing a decrease in the voltage applied to the ADC input (pin 6) of IC1. Below about 1.88V, output 2 (pin 5) of the micro is set high, turning on Q1 and energising the relay. A second thermistor (TH2) is used in the top leg of the divider to minimise voltage fluctuations due to changes in ambient temperature. The reminder beeps are produced by a piezo buzzer on output 4 (pin 3). The software is squeezed into 122 bytes of PICAXE memory. The “mainloop” routine reads the ADC input and compares the result with 96 (corresponding to about 1.88V) to determine if the fan should be started. Without a vectored interrupt feature on this chip, the momentary switch (S1) input must be checked repeatedly within the main and timing loops for high (switch pressed) status. To achieve timing in minutes and to provide appropriate timing points, three for…next loops are nested. To alter the timing period, b2 may be set to 67, 90 or 112 for approx. 3, 4 or 5-minute periods, respectively. Pressing S1 will stop the fan if it’s already running or start it if not. A 2-minute cooling-off period is included after the fan stops so that it doesn’t start again immediately if the water temperature remains above the set point. A 2-second debounce period is invoked after a high status is detected on the switch input. Calibration simply involves setting the voltage at the PICAXE’s ADC input (pin 6) close to 2.1V using trimpot VR1. TH1 should be strapped to the shower pipe near the rosette (insulate its leads) and TH2 should be exposed to room temperature. Both thermistors are of the same type (DSE Cat. R 1895). An electrician should handle all 240VAC mains wiring, while batteries or a plugpack should be used to power the circuit. W. A. Fitzsimons, Mount Eliza, Vic. ($45) Issues Getting Dog-Eared? Keep your copies safe with these handy binders. REAL VALUE AT $12.95 PLUS P & P Available Aust, only. Price: $A12.95 plus $7 p&p per order (includes GST). Just fill in and mail the handy order form in this issue; or fax (02) 9979 6503; or ring (02) 9979 5644 and quote your credit card number. 74 Silicon Chip siliconchip.com.au 'Bathroom Exhaust Fan Controller - 9/2/2005 'PICAXE-08 mainloop: readadc 1,b0 if b0 < 96 then timer1 if input3 = 1 then timer1 goto mainloop timer1: b1 = 0 high 2 pause 2000 timer2: for b4 = 1 to 8 if input3 = 1 then fanoff1 for b3 = 1 to 243 if input3 = 1 then fanoff1 for b2 = 1 to 90 if input3 = 1 then fanoff1 next b2 next b3 if b4 = 4 then beep1 if b4 = 8 then beep2 RCM3400 'reset delay flag 'turn fan on 'debouncing for input 3 'start timer Feature rich, compiler, editor & debugger with royalty free TCP/IP stack Tel: + 61 2 9906 6988 Fax: + 61 2 9906 7145 www.dominion.net.au 4007 Ozitronics www.ozitronics.com Tel: (03) 9434 3806 Fax: (03) 9011 6220 Email: sales2005<at>ozitronics.com '67=3min, 90=4min, 112=5min K142. 12 channel IR relay board $92.40 Control 12 onboard relays with included IR remote. Relays in 2 groups. Each group can be momentary or toggling. 15m+ range. K153. DTMF Tone Grabber $40.15 '1/2 way reminder 'for timer completion Detect DTMF tones direct from phone line or via onboard microphone. Last 32 digits detected stored and displayed on 16x1 CD which can be scrolled left or right. Also each digit is output as ASCII data via serial port. Prices include GST – shipping extra. Full documentation available from website. '1 beep on output 4 or turn fan off after delay 'after delay period turn fan off '1 beep on output 4 beep2: pulsout 4,65535 pause 1000 pulsout 4,65535 goto beep '2 beeps on output 4 siliconchip.com.au Fax a copy of this ad and receive a 5% discount on your order! • Prices exclude GST and delivery charges. beep1: if b1 = 1 then fanoff pulsout 4,65535 goto beep fanoff: b1 = 0 low 2 pause 2000 goto mainloop From $295* 'read voltage divider 'hot water temperature turns the fan on 'momentary switch takes input high beep: next b4 goto fanoff fanoff1: if b1 = 1 then timer1 readadc 1,b0 if b0 > 96 then fanoff if b0 = 96 then fanoff b1 = 1 low 2 pause 2000 goto timer2 Select your microcontroller kit and get started... CONTRIBUTE AND WIN! 'if delay flag is set then turn fan on 'no delay required 'no delay required 'set delay flag 'stop fan 'debouncing for input 3 'reset delay flag 'stop fan 'debouncing for input 3 As you can see, we pay good money for each of the “Circuit Notebook” contributions published in SILICON CHIP. But now there’s an even better reason to send in your circuit idea: each month, the best contribution published will win a superb Peak Atlas LCR Meter valued at $195.00. So don’t keep that brilliant circuit secret any more: send it to SILICON CHIP and you could be a winner! May 2005 75 Circuit Notebook – Continued Automotive LED timing light A useful timing strobe can be constructed using high-brightness LEDs and a few common components. Ignition pulses from the number 1 cylinder high-tension lead are used to trigger the circuit via a homemade inductive pickup. Transistors Q1 & Q2 buffer and amplify the pulses from the pickup, which then drive the inputs of three Schmitt-trigger inverters (IC1a, IC1c & IC1f). Each positive pulse at the inverter inputs causes a low pulse at their outputs, forward-biasing D2 and immediately discharging the 6.8nF capacitor. When the capacitor is discharged, the inputs of the second bank of three inverters (IC1b, IC1d & IC1e) see a logic low level, so their outputs go high, driving Q3 into conduction and powering the LED array. After the pulse ends, the IC1a, IC1c & IC1f inverter outputs return high, reverse biasing D2. However, it takes some time for the 6.8nF capacitor to charge to the logic high threshold voltage of the inverters’ inputs, effectively stretching the initial pulse width and lighting the LEDs for the required amount of time. Low-voltage cutout for 12V SLA batteries Your probing questions answered This simple but extremely useful idea lets you easily attach various extensions to your multimeter’s probes, thus eliminating the need for a full-length test lead set for each type of probe end. As shown in the accompanying illustration, a series of whatever ends you normally use (hooks, al76 Silicon Chip ligator clips, etc) can be fitted with lengths of flexible cable and terminated with PC board pin sockets (Jaycar Cat. HP-1260). As shown, the joins are insulated with heatshrink tubing. Your custom designed extensions can be stored in a zip-lock bag with your multimeter so that they don’t get lost or damaged. Bob Hammond, Engadine, NSW. ($35) This simple circuit protects an SLA battery from over-discharge by disconnecting the load when the terminal voltage drops below a preset level. In operation, a sample of the battery voltage is derived from the 22kW resistor and 20kW trimpot divider. This is applied to the noninverting input (pin 3) of IC1, where it is compared with a reference voltage on the inverting input (pin 2). When the sampled battery voltage falls below the reference voltage, IC1’s output (pin 1) swings towards ground, switching Mosfet Q2 off and disconnecting the load from the battery. The reference voltage is derived siliconchip.com.au The pickup can be salvaged from an old Xenon timing light or made up from a “C” type ferrite or powered iron core large enough to fit around a HT lead. Some experimentation will be required to determine the number of turns required to achieve reliable triggering. About 100 turns of light-gauge wire proved sufficient on the prototype. A cleat is used to close the magnetic path around the lead and is held in place with a large battery clip. Miniature screened microphone cable can be used to connect the pickup to the circuit, to prevent interference from other sources. Refer to the Current Clamp Adapter project in the September 2003 issue of SILICON CHIP for more ideas on how to make the core and clamp assembly. K. J. Benic, Forestville, NSW. ($40) from a 4.7V zener diode (ZD1), which is connected to ground via the collector-emitter circuit of Q1 (ie, when Q1 is on). However, when the op amp’s output is driven low, Q1 is switched off, causing the noninverting input to rise towards the full battery voltage. This greatly reinforces the switching action, latching the circuit in the “off” state until the battery is recharged and the reset switch (S1) pressed. The Mosfet used for Q2 should be selected to suit the intended application. The circuit could also drive a relay simply by connecting the coil across the “load” terminals. As is usual practice, a diode should be connected across the relay coil to limit back-EMF spikes. Tim Nuske, SC Horsham, Vic. ($35) siliconchip.com.au May 2005 77 SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ PRODUCT SHOWCASE Me ’n’ me mate wanna hook up a wireless network . . . Rob Clark, of Freenet-Antennas, reckons he’s heard that line at least a million times. OK, slight exaggeration but he has heard it so many times he’s decided to do something about it. He’s released his “MnM” pack. No, it’s nothing to do with little chocky things – his MnM pack contains all the goodies you and your mate need to set up a wireless network. Yes, MnM does stand for “me ’n’ me mate!” Even though he’s a regular advertiser and sometime contributor to SILICON CHIP, we actually spoke to Rob for the first time while researching the “WiFi” article elsewhere in this issue (and next, and next!). Rob is a very knowledgable bloke when it comes to Wi-Fi. He was semiretired after a technical career in (sorry, if we told you we’d then have to kill you). Freenet-Antennas was set up to keep his mind (and body) sort-of occupied . . . and it’s grown like topsy. Now the business offers a wide range of gear, mainly for Wi-Fi, and then mainly to get the most out of a Wi-Fi setup. Its motto is “specializing in long-distance wireless networking.” Even Stan Swan was impressed when we told him that Rob’s best WiFi link to date, with off-the-shelf gear, nothing illegal, was 29km. “If you pay a bit more for premium equipment, you get significantly better results,” said Rob. “Apart from choosing the right antenna, the one thing that makes a lot of difference is the quality of the antenna cable.” Anyway, back to the MnM pack. In it you receive everything you need to make half of a working “Me ’n’ me mate” link, except the antenna pole. You need two kits to make a complete link – yours and your mate’s. There are four main components to the MnM Pack: a quality Wireless Access Point (AP), 3m of low-loss antenna cable, 15m of Power-over-Ethernet cable (means your AP doesn’t have to be close to a power point) and, of course, the antenna. You choose the antenna according to the distance you want. There’s no point paying top dollar for a high gain antenna if you only want to go, say, 100m. But if you need it, their 24dBi Grid Antenna will get you to the horizon! You’ll find a lot more information on the Freenet-Antennas website. Specifically, the me ’n’ me mate pack can be found at www.freenet-antennas. com/~freenet-/oscommerce-2.2ms2/ catalog/product_info.php?products_ id=136 Contact: Freenet-Antennas Tel: (08) 9319 3275 Fax: (08) 9319 1720 Website: www.freenet-antennas.com Jaycar’s technical forum answers questions Jaycar Electronics has an innovative new approach to solving your product related questions with an ‘interactive’ online forum. Customers can post questions to the forum and Jaycar will encourage fellow users to provide clear and simple answers to them. The answers judged the best by the Jaycar moderator will be awarded a monthly prize of a $100 Jaycar gift voucher. But that’s not all. The best answer to the trickiest question each three months will receive a $500 gift voucher and the answer deemed the best each year will receive a $1,000 reward. See the website at www.jaycar.com.au for full details Commencement of the new forum coincides with the launch of Jay- SILICON CHIP WebLINK How many times have you wanted to access a company’s website but cannot remember their site name? Here's an exciting new concept from SILICON CHIP: you can access any of these organisations instantly by going to the SILICON CHIP website (siliconchip.com.au), clicking on WebLINK and then on the website graphic of the company you’re looking for. It’s that simple. 82 Silicon 82 S ilicon C Chip hip car’s new website, which features a significantly improved search engine, express ordering and 128-bit security. Contact: Jaycar Electronics PO Box 6424, Silverwater NSW 1811. Tel: 1800 022 888 Fax: (02) 9741 8500 Website: www.jaycar.com.au Our website is updated daily, with over 5,500 products available through our secure online ordering facility. Features include semiconductor data sheets, media releases, software downloads, and much more. JAYCAR JAYCAR ELECTRONICS ELECTRONICS Tel: 1800 022 888 Tel: 1800 022 888 WebLINK: WebLINK: www.jaycar.com.au www.jaycar.com.au siliconchip.com.au Heat pump technology means big hot water savings A new commercial hot water system, designed for dairy farms in particular uses heat pump technology to cut energy consumption and costs by up to 30%. The new Wilson Hot Water Systems ECOHP commercial hot water system incorporaties a Quantum commercial heat pump in its design. Among other farm activities, it is ideal for the sterilisation and wash down of milking machines and lines, The heat pump recovers energy from ambient air and waste heat from building and machine exhausts. The energy recovered is then used to pre-heat the system’s water. The heat pump operates by using refrigerant, which is colder than air, collecting heat energy from the ambient air passing through a coil. A typical dairy farm with a 1000l hot water requirement could save 11,315kWh per year. The ECOHP System can further boost water temperature by accessing off-peak power. AUDIO MODULES broadcast quality Contact: Wilson Hot Water Pty Ltd Unit 4, 54 Malvern Street Bayswater 3153 Tel: 1800 30 20 50 Website: www.wilsonhotwater.com.au Manufactured in Australia Harbuch Electronics Pty Ltd 9/40 Leighton Pl. HORNSBY 2077 Ph (02) 9476-5854 Fx (02) 9476-3231 Free catalog download from Tektronix “World’s First” RFID Wireless Mouse Cordless optical meeces are hardly big news these days. But this one is! Microgram have released what is claimed to be the world’s first, no battery, RFID mouse. RFID? The USB-powered mouse pad detects the mouse’s position by Radio Frequency Identification technology, thereby saving interference from a wireless signal and, most importantly, batteries. The mouse itself is a lightweight, sleek, 2-button and wheel design which feels very “natural” in the hand. Having no cable makes is a real boon – there’s nothing to get tangled! The mousepad, an integral part of the system, is large enough without being obtrusive. Its one drawback is not being able to be used on a metal surfaced table – but that’s rare. It must also be kept at least 200mm away from a CRT-equipped monitor. Installation of the mouse is as simple as connecting to a vacant USB port and pressing the “tune” button on the mousepad. It is competitively priced at $49.00 inc. GST and is available from Microgram Computers or their authorised re-sellers. The 2005 Tektronix Product Catalog is packed with essential new updates on oscilloscopes, logic analysers, mobile protocol testing, video test products, signal sources and spectrum analysers. Tektronix claim you will need this newly updated version to keep yourself at the cutting edge of testing, measurement and monitoring. You can find out about a portfolio of products in the design and manufacturing, network monitoring, video test, signal sources, and RF tools markets, all designed to meet your challenging needs. Go to http://enews.tektronix.com/ Key=9620.JVS.C.S.Fmz322 Contact: Contact: 1/14 Bon Mace Cl, Berkeley Vale 2261 Tel: (02) 4389 8444 Fax: (02) 4389 8388 Website: www.microgram.com.au 3 Byfield St, North Ryde NSW 2113 Tel:(02) 9888 0100 Fax:(02) 9888 0125 Website: www.newtekinstruments.com Microgram Computers NewTek Instruments This valuable WebLINK Space for Rent! JED designs and manufactures a range of single board computers (based on Wilke Tiger and Atmel AVR), as well as LCD displays and analog and digital I/O for PCs and controllers. JED also makes a PC PROM programmer and RS232/RS485 converters. Jed Microprocessors Pty Ltd Tel: (03) 9762 3588 Fax: (03) 9762 5499 WebLINK: jedmicro.com.au siliconchip.com.au A 100% Australian owned company supplying frequency control products to the highest international standards: filters, DIL’s, voltage, temperature compensated and oven controlled oscillators, monolithic and discrete filters and ceramic filters and resonators. Hy-Q International Pty Ltd Tel:(03) 9562-8222 Fax: (03) 9562 9009 WebLINK: www.hy-q.com.au We specialise in providing a range of Low Power Radio solutions for OEM’s to incorporate in their wireless technology based products. The innovative range includes products from MK Consultants, the world-renowned specialist manufacturer. TeleLink Communications Tel:(07) 4934 0413 Fax: (07) 4934 0311 WebLINK: telelink.com.au Want to be NOTICED? Without costing you a fortune? To reserve your place in SILICON CHIP WebLINK, email BENEDICTUS SMITH Pty Ltd info<at>benedictus-smith.com December May ay2004 83 2005 83 M 2005 83 Elnec SmartProg2 Programmer Elnec have recently added the SmartProg2 to their range of IC programmers. The SmartProg2 is a universal IC programmer (it can program nearly 11,000 different IC types) with a 40-pin DIL ZIF socket. It is similar to the popular SmartProg except that it has a USB interface. The SmartProg2 is only 160 x 95 x 35mm, has a rugged metal enclosure, an In-System Programming port and is supplied with software, power supply and cables. Software updates are released roughly every 2 weeks and are free from www.elnec.com. List price is $630+GST. For this month only, you can get a SmartProg2 for only $600+GST. Contact: Grantronics Pty Ltd PO Box 275, Wentworthville NSW 2145 Tel: (02) 9896 7150 Fax: (02) 9896 7153 Website: www.grantronics.com.au DSE’s whome 2.4GHz audio/video sender Farnell InOne’s RoHS catalog The electronics industry’s first RoHS (Restriction of the use of certain Hazardous Substances) Directive compliant catalog is now available from Farnell InOne. Containing over 1,600 RoHS compliant products, from suppliers such as National Semiconductor, EPCOS and AVX, the first issue has been mailed to over 160,000 customers across 13 countries including Australia and New Zealand. Also contained in the catalogue is ‘A Step-by-Step Guide to Compliance with the RoHS Directive’, a countdown to compliance and answers to some of the most frequently asked questions. In addition to being available via the catalog, all compliant products are also flagged on Farnell InOne’s website – www.farnellinone.com. au, where design engineers can find products using ‘RoHS’ as a search parameter. The website will be continually updated as new RoHS compliant products become available. Copies of the catalog are available by calling Farnell InOne. Contact: “whome”? Wireless home, of course! They say it brings the digitally connected home to reality. W Home Automation is backed by a pretty big player, globally (SkyNetGlobal) and now DSE has this first offering, a 2.4GHz audio/video sender that can distribute not just audio and video around the home but also allows you to use your remote control from any room. Use it with DVDs, Pay TV, VCRs, etc – or send video or MP3 sound (full stereo) from your computer to your sound system. It has a range of up to about 30m. What you see in the photo above is what you get in the kit – the wireless video transmitter and receiver, two power supplies and a collection of cables to give you just about unlimited Contact: Dick Smith Electronics (all stores) Reply Paid 500, PO Box 500, Regents Park DC NSW 2143. Tel: 1300 366 644 Fax: (02) 9642 9155 Website: www.dse.com.au 84 Silicon Chip flexibility. There’s even a 3.5mm to RCA socket adaptor! It’s available at all DSE and PowerHouse stores. Farnell InOne PMB 6, Chester Hill NSW 2162 Tel: 1300 361 005 (NZ 0800 90 80 80) Website: www.farnellinone.com Jaycar opens two new stores in Aust & NZ Electronics enthusiasts in the southern Sydney suburb of Alexandria and New Zealand city of Hamilton now have their own ‘local’ Jaycar stores. Both stores carry Jaycar’s full product range and will cater to the needs of electronics enthusiasts & hobbyists. The new stores will also provide the area’s tradesmen with ready access to Jaycar’s range of electronic components, tools, wire & cable, access control systems, etc. The stores are staffed by enthusiasts who understand the products they sell and can provide their customers with knowledgeable advice that few other stores can give. Products include car alarm systems, test equipment, video surveillance equipment, car audio, electrical & electronic tools, wire, cable, accessories, and kits. The new stores are located at – Alexandria: 647 Botany Rd, Roseberry NSW 2015 Ph (02) 96994699 Hamilton (shown above): 90-92 Commerce St Frankton, NZ Ph (07) 846-0177 Contact: Jaycar Electronics PO Box 6424, Silverwater NSW 1811. Tel: 1800 022 888 Fax: (02) 9741 8500 Website: www.jaycar.com.au siliconchip.com.au LS1 (NEW) 40mW+ GREEN LASER **WARNING: Only qualified persons should use these components as the dangers of high HEADS: With a 90-240VAC / 50-60Hz power supply, voltage and high intensity laser energy both apply!!! Death & blindness are both potential laser 34 x 34 x 80mm; 240vAC power supply 95 x dangers if used and handled or installed incorrectly. 52mm. $270 FLY1 (NEW) laser light show: LS2 (NEW) 40mW+635nm RED LASER HEADS Supplied with a small 100-240VAC / 50-60Hz. Output T h i s p r o f e s s i o n a l quality light show 5VDC / 500mA, 21mm x 56mm $200 features: Solid state LS3 (NEW)BLUE laser diode 20mW: $1300 For more info on these and other laser diode, and emits LASER LDS1 (NEW) 2 colour laser light show: lasers check out our web site. a powerful 30mW at a Uses 2 lasers, red and green...$640 LDS2 (NEW) 3 colour laser light show: wavelength of 532nm, emerald green(DPSS). It is housed in a quality built housing with mounting Uses 2 lasers & mixes both for 3rd colour. $700 bracket Cooling: air cooling, Power supply: 240Vac (Some 240VAC mains wiring may be required), Some mains wiring is required with all of these lasers Output: 30mW, Control: sound / auto-play, dimensions: 340 X 116 X 119mm, Weight: 3.5Kg. ..$380 LS2 POWERFUL DC MOTORS / GENERATORS: 4 brush, 4 magnet, 16 pole. 11 tooth sprocket to suit a chain pitch around 7mm. Double ball bearing for long life. Mounting bracket with 4 threaded holes 6mm X 1mm (M6) 100mm Dia. x 80mm L (+ shaft) Shaft: 27mm x 8mm (8mm x 1.25mm. (M8) 2kg. 200W 24VDC, 11.0A, 2750 RPM, $30 (SC200) AMAZING LIGHTING BARGAINS DL240 240V / 50W HALOGEN DOWNLIGHT: With one 240V / 50W Halogen lamp and lamp holder. Colour: Satin Chrome. $7.70 300W 24VDC, 16.4A, 2650 RPM, $36 (SC300) 450W 24VDC, 24.5A, 2500 RPM, $79 (SC450) DL01 GIMBLE MOUNT 250W DC geared motors: LAMP HOLDER: Can be used to drive electric bicycles Halogen lamp not supplied. etc. Specifications: 250W / 24V, No Colour: Brass. $3.70 load RPM: 400, With Load: RPM 320, Torque: 7.46, Chain: 12.7, Sprocket: Z9. These motors would be illegal to SPOT1 LOW VOLTAGE SPOTLIGHT: attach to a bicycle in Australia, as the Single flat head spotlight with twist lock legal limit is 200W, although the voltage face. With 12V electronic transformer. could be limited to reduce the motors output to the legal 200W. Measures 110mm Dia. x 115mm L Includes two 12V 50W Halogen lamps. Colour: Black. $14 (+shaft). Shaft 20mm x 8mm. $79 100W 24VDC, 6.0A, 2300 RPM, $22 (SC100) SPOT2 TWO LIGHT BAR SPOTLIGHT: WE HAVE SPEED CONTROLLERS, THROTTLES, 2 head barlight. Dimmable 12V electronic transformers. BATTERIES AND CHARGERS TO SUIT THESE Inc. 4X 12V 50W Halogen lamps. Colour: Black. $28 MOTORS, CHECK OUT OUR WEB SITE FOR MORE DETAILS. NEW 400W WIND GENERATOR: This is a very efficient machine and is designed to run maintenance free even in marine environments. Precision injection molded blades. Consistent aerodynamic outline and mass distribution guarantees the rotors operate at nearly no noise and minimal vibration. Very low start-up/cut-in wind speed, high wind energy coefficient. Designed to prevent blades from feathering. High quality permanent magnet design. Winding and axle are designed to reduce start-up torque, allowing unit to generate at very low wind speeds. High quality aluminum casted body, ensures efficient cooling and is aesthetically pleasing. Designed to operate under severe conditions. Rotor diameter 1.4m, Start up wind speed 2.4m.s-1, Cut-in wind speed 3.0m.s-1, Rated wind speed 12.5 m.s-1, Turbine Rated output 400W,AC12V, Survival wind speed 60 m.s-1 NOTE: There is no mast included in the kit. (WG2) $1050 Mast kit special: Our 4.5M 3 section mast comes with steel guy wires, turnbuckles, ground anchors, nuts and bolts.....all the hardware you will need. $120. NOTE: If used with our new 400W Wind Generator you will need to make a suitable adaptor as the pipe size is not the same. NOW ON SALE FOR ONLY $449 (NEW) 250W WIND GENERATOR: These are serious three phase 250W wind generators with blades spanning 2.2M. They are designed to start operating in low air speeds (around 11kph) while being robust enough to withstand strong gales. These generators are rated at 200W <at> 25kph with a maximum of 250W, output voltages 12V or 24V. The charger kit (included with the generator) will enable you to charge banks of batteries. Each generator is supplied with mounting plate, three blades, tail fin, nosecone, heavy duty cable, 3 section galvanised mast , galvanised steel guy wires, turnbuckles, ground anchors, nuts & bolts..... all the hardware you will need to build your own wind generator. Also included is a three phase rectifier unit with voltage and amperage metering. These wind generators come in two boxes: Box 1 is 45kg (720 x 440 x 230mm), Box 2 is 27.5kg (1540 x 220 x 110mm). For more information and instructions see our web site. FLY1 LS1 NEW KITS K224 3 CHANNEL TO 7 CHANEL INFRA-RED REMOTE CONTROL KIT Up to three kits can be used together to make a 21 Ch. system to operate from one remote control. The basic kit includes the PCB and all onboard components to build a 3 Ch. IR remote control including relays and screw terminals. The additional components required to expand to 7 Ch. are available in the K224E kit. If not used the remaining 4Ch. section of the PCB can be snapped off to reduce the overall size of the kit. 3 channel kit $25 (K224R) 4 channel expansion kit $11(K224E) Remote control (pre-built)$6 (K224T) Complete package 7 channel kit with remote control $39 (K224P) NEW K220 12 or 24V SHUNT REGULATOR KIT. Ideal for wind generators or solar power systems.It can be expanded for up to 250W operation or SPOT3 THREE LIGHT BAR SPOTLIGHT: 3 head barlight. Dimmable 12V electronic transformers. greater with heatsinking. This kit includes PCB and all onboard components for a basic 50W plus Inc. 6X 12V 50W Halogen lamps. Colour: Black. $42 shunt regulator kit. $22 THREE LIGHT ROUND PLATE SPOTLIGHT: Three head round plate. Dimmable 12V electronic transformers. Inc. 6X 12V 50W Halogen lamps. BLACK (SPOT4B) $42. WHITE (SPOT4W) $42 SPOT5 TRACK MOUNTED SPOTLIGHT: Track mounted collar head spotlight with 12V electronic transformer. Track not included. Inc. two 12V 50W Halogen lamps. Colour: Brass. $7 NEW KIT...K221 SERIAL LCD INTERFACE This kit provides an interface between a 2400 baud serial line and common character type LCDs that use a HD44780 interface. It can use inverted or non-inverted data from a PC, PICAXE, or other processor. Features include software controlled variable backlight intensity, two auxiliary digital outputs & a "beep" output to drive a peizo speaker. The layout of HL1 (NEW) 12V / 50W HALOGEN this kit allows easy connection DICHROIC LAMP: to 14 and 16 pin single row In original packaging. 12 Volts, 50W, 60° . and double row type LCD 50mm Dia. x 38mm. 1x 50W HALOGEN connections. The serial interDICHROIC LAMP: (HL1) $2.50. face is TTL. That is, the ideal HALOGEN DICHROIC LAMP: 10x 50W (HL1PK) $16. state is a TTL logic one, or near +5 VDC. For more CFL1 (NEW) 10W COMPACT FLUORESCENT LAMP: details check out our web 220-240 Volts, 10 Watts, Edison screw, Up to 6000 hrs, site. The kit includes a PCB, 1X10W : (CFL1) $3. 6X10W : (CFL1PK) $12.50 programmed PIC16F628 or Special!!! One CFL Inverter Kit + 4 CFL1 for only $30 similar PIC IC and onboard components. $20... $30 when purchased with a DL6 LCD. CFL2 (NEW) 17W COMPACT FLUORESCENT LAMP: (DL6) 16x2 BACKLIT LCD: Standard Hitachi chipset. 220-240 Volts, 17 W, Edison screw, Up to 6000 hours, Mounted on PCB with LED backlight, onboard piezo 1x17W : (CFL2) $4... 6x17W : (CFL2PK) $18 buzzer driver and a piezo transducer, microswitch, two CFL3 (NEW) 10W COMPACT FLUORESCENT LAMP: colour LED. $12 220-240 Volts, 10W, Bayonet base, Up to 6000 hrs, More details on these and other new kits at 1x10W lamp:(CFL3) $3.50...6x10W lamp:(CFL3PK) $15 www.oatleyelectronics.com www.oatleyelectronics.com Suppliers of kits and surplus electronics to hobbyists, experimenters, industry & professionals. Orders: Ph ( 02 ) 9584 3563, Fax 9584 3561, sales<at>oatleyelectronics.com, PO BoxM 89 NSW 2223 OR www.oatleye.com siliconchip.com.au ayOatley 2005 85 major credit cards accepted, Post & Pack typically $7 Prices subject to change without notice ACN 068 740 081 ABN18068 740 081 SC_MAY_05 PICAXE Part 1: Assembling your Schools Experimenter board In the first part of this new series, we look at how to build and test a very low cost experimenter’s kit based on the PICAXE-08M microcontroller chip. Next month, we will introduce some more formal programming exercises for schools to use in the classroom. D ubbed the “Schools Experimenter”, this versatile design allows simple exercises to learn the BASIC programming language using LEDs and simple sensors, but the board can also be used alongside a breadboard prototyping system for much more advanced experiments. What is a microcontroller? Microcontrollers are single-chip computers that are finding use in just about every electronically enabled device you care to name. Toys, mobile phones, microwave ovens and MP3 players are just a small sample of the consumer items now microcontroller equipped. The “PICAXE” system is a power- # About the Author: Clive Seager is the Technical Director of Revolution Education Ltd, the developers of the PICAXE system. 86 Silicon Chip by Clive Seager # ful, yet very low cost microcontroller programming system designed to simplify educational and hobbyist use of these devices. A unique feature of the PICAXE system is that no special programming hardware is required. Programs that you write on your PC using free Windows software can be downloaded straight into the microcontroller chip with a direct cable connection. This low-cost approach also means Table 1: PICAXE-08M Pinouts and Functions Pin 1 2 3 4 5 6 7 8 Function Description +V Power supply positive (4.5V to 5V only) SERIN Serial input for programming IN 4/OUT 4 General-purpose input/output 4 IN 3 Digital input 3 IN 2/OUT 2 General-purpose input/output 2 IN 1/OUT 1 General-purpose input/output 1 OUT 0 Output 0 (also used as serial output) 0V Power supply ground (0V) Use LDR input Switch input Green LED Yellow LED Red LED - siliconchip.com.au that students can use the whole programming system at home. Naturally, the easiest-to-use member of the PICAXE family, the PICAXE-08M, was chosen for use in this project. It is contained in an 8-pin dual-in-line (DIL) IC package. Two pins connect to the power source, two more are used for downloading the BASIC programs while the remaining four are general-purpose inputs and outputs. These can be used to control LEDs and relays, make sounds, read sensors, etc. Some pins have alternate functions, which we’ll explore in more detail in future articles. Schools Experimenter In short, the Schools Experimenter board provides a socket for the PICAXE-08M microcontroller as well as a series of simple devices (LEDs, switches, etc) that you can control and interrogate with your BASIC programs. A socket is also included for programming purposes. More detail is to be had from the complete circuit diagram in Fig.1. Red, yellow and green LEDs are connected to the first three outputs (outputs 0, 1 and 2) of the PICAXE. A 330W resistor in series with each output limits LED current flow to less than 10mA. A piezo transducer can also be connected to output 2 for making sounds and playing musical tunes. Not surprisingly, a miniature push-button switch (SW1) on input 3 and a light dependent resistor (LDR) on input 4 act as the on-board input devices. Each input has a 10kW pulldown resistor (to the 0V rail) to ensure correct operation; this will be explained in more detail next month. A serial download socket and 10kW and 22kW resistors make up the computer interface for programming. The PC board also contains provision for a 10-pin header strip (H1) that enables each of the input/output pins to be connected to a breadboard for more advanced experiments. The three holes marked “H2” are reserved for future use and can be ignored at present. Finally, a 100nF capacitor is included for siliconchip.com.au CALLING ALL SCHOOLS with electronics/technology courses: Want some FREE PICAXE PC boards? Here’s an offer you don’t see every day: FREE PICAXE blank project PC boards. Yes, free. Or gratis, zip, zilch, without charge, nothing... just as long as you qualify AND you’re quick! To celebrate the launch of our “PICAXE in Schools” column, Revolution Education Ltd has kindly donated 2000 “Schools Experimenter” PC boards, as used in this feature, to be given away, free of charge, to Australian and New Zealand High Schools. The first 200 teachers to email (NOT phone!) their full name, school, position and school address to siliconchipoffer<at>microzed.com.au will each receive not 1, not 2 but a whole 10 PC boards – absolutely free of charge! Your email will be acknowledged within 24 hours but please allow up to 30 days for delivery. * The fine print: limit 10 boards per school. Blank PC boards and programming sockets only supplied (ie, no components), as shown above. Strictly while stocks last, and in order of receipt. For special deals on kits of parts, visit www.microzed.com.au high-frequency power supply decoupling. Table 1 shows the function of each physical pin on the PICAXE08M chip and how it is used on the Experimenter’s board. Note that the 4-pole dual-in-line (DIL) switch on the PC board can be used to disconnect the LEDs, switch and LDR from the PICAXE input/outputs. This allows the input/outputs to be used for other purposes when experimenting with a breadboard. For the time being, all four contacts of the switch must be closed (set to the “ON” position). Putting it all together Assembly of the Schools ExperiMay 2005 87 Fig.1: the complete circuit diagram shows how simple it is – there are only about a dozen components! menter is quite straight-forward. Begin by soldering all of the resistors in place using the overlay diagram in Fig.2 as a guide. We’ve shown all the resistor colour codes (all three of them) in a table elsewhere in this feature. Alternatively (or as well as?), a quick check with your multimeter will also confirm resistance values. Next, install the IC socket for the microcontroller (IC1) followed by the two switches (SW1 & SW2). The 4-pole DIL switch (SW2) must go in the correct way around (see photos). The serial programming socket can be installed next; make sure that it is pushed right down on the surface of the PC board before soldering. Follow with the three LEDs, The completed schools Experimenter, ready for the addition of a 4.5V battery pack (ie, 3 x AA cells, NOT 4!) 88 Silicon Chip siliconchip.com.au Fig.2: Here’s how to place the components on the PC board. Use a socket for IC1. LDR and 10-pin header (H1). Note that with the flat (cathode) sides of the LEDs must be oriented as shown, while the LDR can sit about 5mm proud of the board surface. The last job is to solder the wires for the battery clip and piezo to their respective pairs of pads. Pass the wires through the adjacent strain-relief holes before soldering (see photos). Make sure that the positive (red) wires connect to the pads marked “+”! When inserting the PICAXE-08M into its socket, it is very important that the indented (pin 1) end is oriented as shown on the overlay diagram and photos. Your completed project should be powered from a 3 x AA alkaline cell (4.5V) battery pack or a regulated 5V DC supply. Never use a 9V PP3 battery, as this is way above the voltage rating of the chip. Take particular care that you have the power leads around the right way; otherwise, you’ll destroy the PICAXE chip! Programming introduction The easiest way to check that your board is working properly is to type in a short BASIC program and download it to the PICAXE micro, so let’s do that next. Those new to PICAXE programming will first need to download the Programming Editor software from www.picaxe.co.uk and obtain a low-cost download cable from their local distributor (see parts list). Connect the download cable to the serial port at the back of your siliconchip.com.au Yeah, we know, this photo is turned 90° compared to the overlay at left. But between the two, you should be able to identify and place all components. Parts List – PICAXE Schools Experimenter 1 1 1 1 1 1 1 1 1 1 AXE092 PC board 3.5mm stereo socket miniature pushbutton switch (SW1) 4-pole DIL switch (SW2) 8-pin IC socket miniature piezo transducer 10-pin SIL 2.54mm (0.1”) pitch header (H1) 100nF polyester capacitor (code 100n or 0.1mF) battery clip 3 x AA battery holder Semiconductors 1 PICAXE-08M 1 5mm green LED 1 5mm red LED 1 5mm yellow LED Resistors (0.25W 5%) 3 10kW 3 330W 1 miniature LDR 1 22kW Also required (not in kit) PICAXE Programming Editor software (v4.1.0 or later) PICAXE download cable (part no. AXE026) 3 x AA alkaline cells Obtaining kits and software The design copyright for this project is owned by Revolution Education Ltd. Complete kits (part no. AXE092K) or the PC board only (part no. AXE092) for this project are available from authorised PICAXE distributors – see www.microzed.com.au and resellers. Phone MicroZed on (02) 6772 2777. The PICAXE Programming Editor software can be downloaded free of charge from www.picaxe.co.uk or ordered on CD (part no. BAS805). May 2005 89 Sample Program main: high 0 pause 500 low 0 high 1 pause 500 low 1 high 2 pause 500 low 2 goto main ‘red LED on ‘wait 0.5 second (=500ms) ‘red LED off ‘yellow LED on ‘wait 0.5 second (=500ms) ‘yellow LED off ‘green LED on ‘wait 0.5 second (=500ms) ‘green LED off ‘jump back to start Fig. 3: a screen grab of the chip and port setup from the programming editor software. Make sure you set the details correctly or it won’t work! In the background is the sample program, again reproduced in Fig. 4 (above right). computer. Note that if you have a late-model laptop without a serial port then you will also need to purchase the USB to Serial Adapter (part no. USB010). After installing and running the Programming Editor software, select View -> Options from the toolbar and configure the software for “PICAXE-08M” mode (see Fig.3) Also, make sure the serial port number (COM1, COM2, etc.) corresponds to the physical port where the cable is connected and then click OK. Now type in the test program shown in Fig.4. Be sure to include all punctuation, including the colon (:) after the first word “main”; this tells the computer that you want the word “main” to be a label. This enables the program to later use the command “goto main”, i.e. jump back to the start. When the program is complete, click PICAXE -> Run to download the program into the PICAXE chip. Note that programming can only be successful if the cable is connected and power is applied to the PC board. All being well, the three LEDs will light in turn. Don’t be worried that the red LED on output 0 flickers during a download; this is normal, as the LED is indicating that the computer and PICAXE chip are communicating. Troubleshooting If the program fails to download, disconnect power and recheck all of your soldering and component placement and orientation. If no problems can be found, use your multimeter to verify that there is 4V The PICAXE has a maximum 5V supply and operates quite - 5V between the happily at 4.5V. For this you need either a special threepower pins (1 & cell “AA” battery holder, as shown here, or a four-cell 8) of the PICAXE modified to take three cells, to ensure that the 5V limit chip when power isn’t exceeded. is connected. Finally, check that the download look at how to write programs that cable is fully inserted in its socket respond to inputs (both digital and and that the serial (COM) port analogue) and how to make sounds chosen under the View -> Options on the piezo transducer. In the meantime, if you’re an menu matches the port that the electronics or technology student cable is physically plugged into. in an Australian or NZ school, make Summary sure you show this article to your Congratulations – you have teacher so your school can claim now assembled and programmed their 10 PC boards. Remember that it is strictly first your first PICAXE microcontroller SC project! Next time around, we’ll come, first served! Resistor Colour Codes o o o Qty. 1 3 3 90 Silicon Chip Value 22kW 10kW 330W 4-Band Code (5%) red red orange gold brown black orange gold orange orange brown gold 5-Band Code (1%) red red black red brown brown black black red brown orange orange black black brown siliconchip.com.au BOOK REVIEW by Ross Tester The Wireless Networking Starter Kit (2nd Edition) by Adam Engst & Glenn Fleishman, Peachpit Press (US), 530+ pages, soft cover Some months ago, I asked our nonresident Wi-Fi guru, Stan Swan, which book he would recommend for a beginner in the field of Wi-Fi (at the time, me!). “None better than The Wireless Networking Starter Kit,” he said. Now that’s some recommendation. So I contacted the publishers and organised a copy. If it was as good as Stan said it was, we’d like to put it in the SILICON CHIP bookshop. In due course, the book arrived – and my first surprise was to find that there was now a second edition. My second, hardly a surprise, was to find that Stan (once again!) knew what he was talking about. This book is one of the best Wi-Fi resources I have found – and by now, I’ve seen quite a lot of them. You might be able to find a lot of the information in this book on the ’net – if you have the time (lots of!) and patience (even more!) to go searching for it. In the Wireless Networking Starter Kit, it’s all there in one handy reference volume. And at the price, it’s very good value for money. Covering both the Windows and Mac environments, it starts with the real basics – how wireless works, the standards, the hardware and so on, even looking into the crystal ball at the (near) future of wireless. In some respects, their prophecies are already coming true – the book was written during mid 2003 so now, two years on, we can see how right the authors were. (They were!). It then moves on to the “nuts and bolts” of wireless networking: how to connect your computer and then building a wireless network. By the time you’ve read through all of this, you should have a very good idea of just what you need and how to string it all together. In fact, you’d probably rate yourself as a power user, if not an expert. Wireless security is covered in some depth. Given the importance of this subject in the 21st century, this is a welsiliconchip.com.au come sight. Not only does it tell you how you can be attacked, it tells you how to prevent attacks in your network. It even tells you how and why WEP encryption is so vulnerable, even going as far as detailing the software capable of breaking WEP. Why? Forewarned is forearmed! The authors then discuss mobile Wi-Fi in a variety of formats. While some of the information is US-specific, it was very interesting to me to read just how and why the various systems evolved and are still evolving. Finally, they talk about long-range Wi-Fi – how to get long distance from a Wi-Fi installation. There are three useful appendices, too: networking basics, configuring your network and settings, and most importantly, how to troubleshoot. Finally, a glossary fills you in on all the Wi-Fi buzzwords. Criticisms? A couple of minor bits of JISP (jumbled interpretation of scientific phenomena). An example: “In the simplest terms, an antenna increases the power of a transceiver.. .” (P32). Umm, no it doesn’t – we think they meant to say an external antenna increases the radiated power of a transceiver, which still isn’t strictly true but it imparts some meaning to readers not versed in RF. They also talk about the US FCC worrying about people connecting “too powerful antennas” which again is misleading. No antenna is any more “powerful” than another because they don’t have “power”. It might be more efficient; it might have higher gain by increasing performance in certain directions and sacrificing performance in others. But more powerful, it ain’t! However, if these quibbles are all we have to report, the authors have done very well indeed in explaining what is still a black science to most people, including many computer users. What we did like is the continuous notes and asides through the book. Did you know, for example, that spreadspectrum technology (the basis for WiFi transmissions) was invented during WWII by the actress Hedy Lamar and kept secret by the US Government? Neither did I! And the opening quote in the book, attributed to Albert Einstein, really tickled my fancy: “The wireless telegraph is not difficult to understand. The ordinary telegraph is like a very long cat. You pull the tail in New York and it meows in Los Angeles. The wireless is the same, without the cat.” For more information on this book (even a “teaser” downloadable chapter) go to www.wireless-starter-kit. com The Wireless Networking Starter Kit is distributed in Australia by Penguin Group and should be available (probably to order) from better bookshops, with a recommended retail price of $49.95. It will also be available from the SILICON CHIP bookshop (online or through the magazine) shortly. SC May 2005 91 Build Your Team A Professional Sports Scoreboard Pt.3: By JIM ROWE This third and final article on the Electronic Scoreboard details the assembly of the display modules and gives the wiring details. Also described is the check-out procedure and there are some hints on driving the Scoreboard. T HE FOUR DISPLAY boards are all wired up in much the same way, although there are a few minor differences. We suggest that you assemble the “Scoreboard Display 1” (Period) board first, as this has the fewest parts. Fig.10 shows the details. This display uses the BSB-D1 board and there is only one wire link to fit – just to the right of the 26-way DIP header. After fitting the link, add the 92 Silicon Chip 26-way DIL header, with its centrelocating slot on the left. Next, fit the three resistors and the 1000mF electrolytic capacitor. You can then fit transistor Q1 (PN100) and the BD136/140 power transistor (Q2). The latter has its leads bent down by 90° about 6mm from its body, so it mounts flat against the board. Secure it to the board using an M3 x 6mm screw and nut before soldering its leads. This board can now be completed by fitting the 28 high-brightness 10mm yellow LEDs which form the display segments. These all mount with their longer anode lead towards the top of the board. In practice, it’s just a matter of pushing each LED right down onto the PC board and then soldering its leads. Do this 28 times and the Period display board is finished. The two “Scoreboard Display 3” (team score) boards are assembled in a similar manner. However, these both have three sets of digit driver components and 67 LEDs each, instead of only 28. These displays are wired up on two identical PC boards coded BSB-D3 – see Fig.11. However, they are customised so that one functions as the “Home Team” display and the other as the “Away Team” display. This is done simply by fitting the three 4.7kW resistors in different positions – ie, in the “Home Team Display” positions for one board and in the “Away Team Display” positions for the other board. This automatically sets the three digits to become either D2, D3 & D4 or D5, D6 & D7, respectively. Note that both of these boards have an extra 22W resistor, located just to the centre right of the column of “1” LEDs. Note also that these two boards use green high-brightness LEDs for all the digit segments. Once you’ve completed the two Team Score displays, you’re ready to tackle the “monster” Countdown Timer display, with its five digit driver circuits and 120 high-brightness siliconchip.com.au NOW ALSO HANDLES NETBALL ! red LEDs. This uses the largest PC board, coded BSB-D4. Fig.12 shows the assembly details for this board. Again, the construction is similar to the other LED display boards. Just be sure to install all the LEDs with the correct polarity. Fig.10 (left): the assembly details for the Scoreboard 1 (Period) display. Take care with the Installing 120 LED orientation. Note: PC overlay shown 64% of actual size. LEDs certainly is a tedious job but it really shouldn’t take that long if you work push M3 x 15mm screws through two then remove the cable and carefully methodically. Solder in a batch of diagonal corner holes in each module, so crimp on that socket, then plug the four at a time and the job will be done that they enter the mounting holes in the cable back into both headers and repeat before you know it. frame. This secures the modules while the process to find the right position for you make up the cable assembly. the “Away Team Display” socket. 26-way ribbon cable This assembly is made up using five This process is repeated until you There should now be only one small 26-way IDC line sockets and a 1600mm end up fitting the socket at the far end job remaining before testing the unit length of 26-way ribbon cable. The and assembling the modules into the location of each connector is shown in Where To Buy A Kit timber frame. This involves making Fig.13, while the small circular insets and installing the 26-way ribbon cable show their orientation and indicate Jaycar Electronics has sponsored that links all the display boards back how they are attached. the development of this project and to the control board. Fig.13 also shows how the cable is they own the design copyright. This job is straightforward, provided dressed, so that it can be used to link A full kit of parts is available from you tackle it in the following way. all five line sockets in a continuous Jaycar – Cat. KC-5408. This kit First, place the timber frame face up on length – and without obscuring any includes the following: a pre-built a table or workbench. That done, place of the displays. wooden display frame with screeneach of the Scoreboard’s PC boards The easiest way to make up the cable printed lettering and individual temporarily on the front of the board, is by crimping on the end “Home Team Perspex covers for the displays; directly in front of their final positions Display” line socket first, then plugscreen-printed and solder-masked inside. The display boards should ging this into that board and dressing PC boards; all on-board parts; and be directly over their “windows”, the cable up and over until you can a control console case with a prewhile the controller board should be see exactly where the next socket will punched front panel and screened squarely over its mounting holes. be – ie, directly over the header on the lettering. Once the modules are in position, Countdown Timer display board. You siliconchip.com.au May 2005 93 Fig.11: this is the Scoreboard 3 (Team score) display assembly. Two slightly different versions of this board must be built, one with the three 4.7kW resistors at top left in the “Home Team” positions and one with the resistors in the “Away Team” positions – see text. Note: PC overlay shown 64% of actual size. Left: this version of the Scoreboard 3 display has the three 4.7kW resistors in the “Away Team” position. of the cable for the controller board. Your cable should then be finished. Checkout time While the boards are all easily accessible and linked together, this is a good time to apply power to the Scoreboard and give it a quick functional check. First, connect a DC plugpack or 12V battery to the controller’s DC power input socket CON1. If all is well, the Countdown Timer display should spring into life after a second or so and show “9:59” in red digits. At the same time, both team-score displays should show a “0” in green digits. Assuming all is well, apply power to the Control Console. The Scoreboard display should “blink” briefly as the Control Console powers up and sends the game code selection command to the Scoreboard controller. 94 Silicon Chip siliconchip.com.au Fig.12 (right): the assembly details for the Countdown Timer display board. As with the other display boards, take care with the LED polarity. Note: PC overlay shown 64% of actual size. If you’ve set the code select DIP switches in the Control Console for FIBA rules, the displays won’t actually change after they “blink”. However, if you’ve set the DIP switches for either NBA or NCAA rules, the Timer display should change to either 11:59 or 19:59 respectively, ready for the start of the first game period in those codes. Now try pressing both of the red “Reset Scoreboard for a New Game” buttons on the Control Console. Nothing should happen on the Scoreboard but the Confirm Reset LED should begin glowing on the console itself. If you now press the two Reset buttons together again, the Scoreboard displays should “blink” as the board is reset, while the LED on the console should now go out. Next, try pressing the green “Start Next Game Period” button. Again the displays should “blink” briefly and the “Current Period” display should show a yellow “1” to indicate that the first game period has started. At the same time, the Timer display should begin counting down in seconds, showing the time left for the current period. Now press one of the scoring buttons for either the Home or Away teams. Which ever button you press, the score for that team should change accordingly – increasing by either 3, 2 or 1, or decreasing by 1 according to the button that’s pressed. Each time you change the score, the displays will “blink” briefly as the PIC micro processes the command from the console but the Timer will continue counting down. If it’s all working so far, wait until the Timer counts down until the remaining time is 1:00 minute. Immediately after this, the Timer’s display should change into “last minute” mode, showing “59.9” and continuing to count down in seconds and tenths of a second. When it finally reaches “0.0”, it will stop and the piezo alarm will emit a loud but brief “end of period” sound. If all of the above happens as expected, your Scoreboard and its Control Console are working as they should. siliconchip.com.au May 2005 95 The Timer display board uses 120 high-brightness red LEDs. It’s straightforward (if a little time-consuming) to build. Fig.13 : the 26-way ribbon cable is folded through a series of 90° bends and used to connect the controller board and the various display boards together. Make sure that the red cable edge stripe is positioned as shown. All that remains now is to attach the Scoreboard modules to the timber frame. First disconnect the power, unplug the 26-way cable and remove 96 Silicon Chip the board modules from the front of the frame. That done, you can attach M3 x 25mm-long tapped spacers to all the module mounting points on the timber frame. These are secured using M3 x 15mm countersink-head screws. Now plug the 26-way ribbon cable’s end connector into the DIL header on siliconchip.com.au This rear view of the display unit clearly shows the locations of the various modules. Several strips of adhesive tape are used to secure the 26-way IDC cable to the back of the timber frame. the Home score display board and – with the cable folded upwards – position it on its six spacers behind the viewing window. Fasten it in place using six M3 x 6mm machine screws, then plug the second cable connector into the DIL header on the Timer display board. Attach this board to its six spacers, then repeat the process for the Away score display board and the Period display board. The Control board is fitted last but before this is done, you need to attach the piezo alarm to the front of the Scoreboard. To do this, feed its leads through the central access hole, then secure the unit to the board using four 15mm long countersunk head woodscrews. With the alarm attached, cut its leads to about 150mm long and connect them to the screw terminal block on the side of the Control board. Tighten the screws firmly to ensure reliable connections. That done, attach the end line socket on the ribbon cable to the Control board’s DIP header and carefully posisiliconchip.com.au tion this board on its 25mm spacers, so that the “Carrier Present” LED passes through its matching 6mm hole in the frame. Finally fasten the board using four 6mm x M3 machine screws. Your electronic Scoreboard is now complete. Using the Scoreboard Driving the Scoreboard is fairly self evident, as all of the buttons on the Control Console are clearly marked to show what they’re used for. The only time you need to press the two Reset buttons (together, and then again) is when you want to reset the Scoreboard completely for a new game. To begin each period within a game, you simply press the green “Start Next Game Period” button once. The Scoreboard then automatically increments the Period display each time, moving to the Extra Time display (“E”) when you use up all the main game periods for the rules you’re playing. Note that the Timer automatically assigns “Extra Time” periods of five minutes. If a “Time Out” is declared, you simply press the white “Time Out” button to temporarily stop the timer. Then at the end of the “Time Out”, you press the blue “Time In” button to restart it from where it was stopped. And that’s really all there is to it – apart from updating the scores of the two teams using the two lower sets of buttons. Changing the rules or game Remember that to change the basketball code (or rules) that are being played, you need to open the console case and change the settings of DIP switch S2. The next time the console is powered up, it will send the correct game code to the Scoreboard. Finally, following reader requests from the first article, the firmware has now been modified to also allow for netball games, which usually have a fourth game period. The timer can be set for the usual 15, 12 or 10 minute quarters and can also be set for two 20 minute halves, SC as used by NCAA. May 2005 97 Vintage Radio By RODNEY CHAMPNESS, VK3UG The AWA Radiola B29 8-transistor radio with battery eliminator Manufactured in the 1960s, the AWA B29 is an interesting 8-transistor radio that could be run from batteries or an external power adapter. T RANSISTOR RADIOS came in three basic sizes during the period that Australian manufacture still existed: small (little bigger than a large pack of cigarettes), medium (about the size of a house brick) and large (about the size of a medium-sized valve portable). During this period, a lot of work was done to reduce the size of the sets while still maintaining good sensitivity and audio output. For example, in medium-sized receivers, 200mm x 12mm-diameter ferrite rods were used to ensure good sensitivity, while the batteries were kept small to keep the size and weight to a reasonable level. Unfortunately, using small batteries also meant that they had to be replaced frequently at some cost. Many of these portables spent more time in the kitchen than outside, although they were also often used for entertainment at the beach. Saving batteries In order to conserve the batteries, manufacturers had to look at ways of minimising or even eliminating battery drain in some circumstances – eg, when the radio was used in the Although still functional, the old AWA Radiola B29 was somewhat worse for wear. It’s a fairly conventional 8-transistor set from the 1960s. 98 Silicon Chip kitchen. The answer was to provide a small external power supply that would allow the set to run off the mains. A switching contact on the set’s power socket isolated the battery when the external supply was plugged in. The AWA B29 8-transistor radio is one such set that can be used with an external power supply (or “battery eliminator”). It was a medium-sized receiver weighing 1.6kg without a battery, or about 1.85kg with its 2364 battery fitted. By contrast, the larger AWA B32 8-transistor receiver (which has an RF stage) weighs 3.2kg without a battery and just under 4kg with its quite sizable battery fitted. The two sets draw around the same current. However, the battery in the B32 is more than three times heavier than the B29’s 2364 battery (800g versus 250g) and it provides nearly four times the operating life. Although hardly a lightweight at 4kg, the B32 weighed much less than the mains-powered valve portables from the 1950s and 1960s. These weighed as much as 8kg, which made them rather heavy to move around. Generally, a high current drain relative to battery size means a short operational life. For example, some small sets used a 216 battery (weighing less than 40g), which meant that operating times were down to just a few hours. By contrast, those sets using four AA cells (52g) did have a longer operational life. There were other options, however. For example, the Kriesler 41-27 used a 286 battery which was reputed to give around 1000 hours of operation. It is a weighty portable (approximately 3.6kg with the battery fitted), although it was lighter than the AWA B32. siliconchip.com.au The B29 is more conveniently sized and is an effective portable receiver when using its internal battery. However, it’s still best to use an external mains adapter to power the set if it is to be used in the home. The A&R PS82 Probably the first manufacturer to provide a battery eliminator was Philips with their circular shaped unit. However, other manufacturers soon climbed aboard the bandwagon. One such company was A & R Transformers and their PS82 battery eliminator was very popular at the time. This unit was double-insulated and featured switchable 6V and 9V (100mA) DC outputs. One advantage of the PS82 is that it is easily dismantled for service, requiring just one screw to be removed to split the case in half. As shown in Fig.1, the circuit is really quite simple and uses diode D1 as a half-wave rectifier. The 6V and 9V settings are selected by switching taps on the transformer secondary, while two electrolytic capacitors and a 10W resistor filter the output from D1. Fitting four diodes in a bridge rectifier circuit would have achieved better voltage regulation under load, so why wasn’t this done? The reason is probably to do with cost. Silicon diodes were much more expensive then than they are now and so this would have sharply increased the cost. The A&R PS82 battery eliminator featured selectable 6V and 9V DC outputs. Fig.1: there’s not much in the A&R PS82 battery eliminator – just a transformer, a diode, a couple of electrolytic capacitors and a switch to select the transformer taps. AWA B29 circuit details The circuit of the AWA B29 is conventional for the era – see Fig.2. First, there is a large ferrite antenna rod and this has three windings: (1) a tuned winding for RF signal pick-up; (2) a transistor base feed winding; and (3) a winding that can be interfaced to an external antenna. Coil L1 connects to this third winding and acts as a loading coil to boost the receiver’s performance with a relatively short antenna (eg, a car radio antenna). The autodyne converter stage uses a 2N1639 or a 2N1636 germanium transistor. Following this is a 2-stage neutralised intermediate frequency (IF) amplifier using either 2N1638 or 2N1634 transistors. The neutralising capacitors are C11 and C17. Note that the IF transformers (TR3-TR5) each have only one tuned winding, their low impedance coils coupling to either siliconchip.com.au the next transistor base or, in the case of TR5, to the detector diode (MR1). The automatic gain control (AGC) voltage from the detector diode is applied to the base of the first IF transistor (VT2). For medium strength signals, AGC control only occurs in the first IF stage. As the AGC voltage increases, the transistor draws more current rather than less as in a valve circuit. This also means that as the AGC voltage rises, the voltage on VT2’s collector drops and this changes the bias on VT3 (2N406) such that it begins to draw current. As a result, VT3 functions a variable shunt across the tuned circuit in TR3, which reduces the signal applied to the first IF amplifier. It’s no exaggeration to say that this type of AGC circuit is foreign to most who have only been involved with valve AGC circuits. Note too that the circuit is drawn with a positive earth, which makes it just that much harder to follow. The detector stage is followed by a conventional 4-transistor amplifier circuit, with transformer TR6 driving a push-pull class B output stage (VT7 & VT8). There is no output transformer, the output transistors directly driving a centre-tapped 80-ohm loudspeaker. Because the speaker is so unusual, you need to keep your fingers crossed that it never needs replacement! By the way, germanium transistors are rather sensitive to temperature and voltage variations. If these factors increase, the output stage draws May 2005 99 more current, which increases the temperature, which leads to a further increase in current and so on. Unless precautions are taken, this can lead to a condition known as thermal runaway and result in the destruction of the output transistors. In this circuit, the current through the output stage is stabilised by a network consisting of R25, R26, R28, R29 and thermistor TH1 (AS2). In operation, TH1 monitors the temperature of the output transistors. As the temperature goes up, the thermistor’s resistance goes down and this reduces the forward bias on the output transistors. As a result, they draw less standing current and so the current through them is kept to a safe limit. Finally, note that because the set has a positive earth, the plug from the external power source must have its centre pin (tip) as the negative output. Most external supplies (including plugpacks) have the centre pin wired as the positive rail, so take care here. Repairing the cabinet Fig.2: the B29 receiver uses a fairly conventional superheterodyne circuit with eight transistors. The audio output stage is a little unusual though, as it drives a centre-tapped loudspeaker coil – see text. 100 Silicon Chip The B29’s case measures 235mm x 120mm x 70mm and is made from brown leather, cardboard and plastic, with a metal front. The front of the set is similar to the B79 described in the December 2004 issue. As can be seen in one of the photographs, the carrying handle had come adrift from the lugs on the top of the case. This method of attaching the handle was obviously inadequate, so I looked at making some improvements here. Unfortunately, this involved dismantling the set and that wasn’t all that easy. First, the handspan tuning knob and the on-off-volume control knob were removed. However, I couldn’t persuade the dial pointer to come off – it is a tight friction fit to the tuning gang shaft. Next, working from the back of the set, the five screws that secure the PC board in place were removed. That done, the loopstick antenna was eased out of its clips and the four nuts (one at each corner of the cabinet at the front) were removed using a small socket wrench (spintite) on an extender shaft By this stage, everything was “flopping” around inside the case and so the dial-scale was now worked backwards and forwards while I tried to remove the PC board assembly. It eventually siliconchip.com.au Removing the “works” from the cabinet isn’t all that easy, the entire process taking around 20 minutes. Note the large loopstick antenna which contributes to the set’s good sensitivity. came free and I was able to extract the PC board, the chassis and the rod antenna from of the case. This gave access to the four bifurcated rivets that hold the handle in place. These rivets (along with the handle) were then removed. That done, I cut some light-gauge galvanised flashing (try your local hardware store) into two small rectangles. These were then bent into semi-circular straps, after which two holes were drilled in each strap to match the holes in the leather handle assembly. The idea behind these metal straps is that they would take all the pressure off the leather handle. The accompanying photographs shows the basic scheme. Re-attaching the handle assembly to the case took a little while but the scheme worked well. It may not look 100% due to the damage that has been done to the various parts over the years but it’s a lot better (and stronger) than it was. The case was also looking a bit shabby, so the next step was to give it a good clean. First, the leather was washed with soapy water on a cloth and then put aside until it was completely dry. It was then polished using silicone wax and came up rather nicely. siliconchip.com.au The front panel of the set was also cleaned using soapy water, this time with the aid of a nail brush. However, this job had to be approached with a good deal of caution, to avoid splashing water onto the paper dial scale. The front panel was then polished, by which time the receiver was starting to look rather good, even in its disassembled state. The knob and handspan dial were also given a wash, ready for the final assembly. However, that would have to wait until the circuit had been checked out. Getting it going It was time for the smoke test. After making sure that the PC board was properly isolated, I connected a power supply and switched the set on. It immediately showed signs of life but the volume control was very noisy. A quick spray with a suitable cleaner solved that particular problem. I then twisted the tuning control shaft with my fingers and a number of stations were heard. I closed the tuning gang and found to my amazement that the set was tuning down to around 495kHz. And with the gang fully open, it tuned all the way up to about 1700kHz. However, the set was never really designed to cover this tuning range. Someone in the past had adjusted the various coils and trimmers so that it covered this range and then flooded the coil cores with beeswax. I was able to readjust the IF coils but the oscilla- VALVES AUDIO HI-FI AMATEUR RADIO GUITAR AMPS INDUSTRIAL VINTAGE RADIO We can supply your valve needs, including high voltage capacitors, Hammond transformers, chassis, sockets and valve books. WE BUY, SELL and TRADE SSAE DL size for CATALOGUE ELECTRONIC VALVE & TUBE COMPANY PO Box 487 Drysdale, Vic 3222 76 Bluff Rd, St Leonards, 3223 Tel: (03) 5257 2297; Fax: (03) 5257 1773 Email: evatco<at>pacific.net.au www.evatco.com.au May 2005 101 The next problem was that the audio sounded rather distorted at high volume, so I starting checking out the audio amplifier. I soon found that the supply rail dropped with increasing volume, getting down as low as 7V. This is lower than I would have liked to have seen and indicates that a full-wave bridge rectifier in the power supply would have been a good idea. As an experiment, I tested the set with a small regulated supply set to 9V. This gave greater output and less The handle assembly on the old B29 was repaired and strengthened using two small metal brackets (above and right). The restored receiver looks good and gives reasonable performance. tor coil is well and truly sealed and so there is no way of adjusting the bottom end of the tuning range. When I obtain a surplus coil from another similar set, I’ll replace it. At the other end of the scale, the top frequency was adjusted to around 1640kHz with the tuning gang fully open. I then peaked the antenna coil near the bottom end of the dial (at about 600kHz) by sliding the tuned winding along the ferrite rod for best reception, after which the set was tuned to about 1500kHz and the antenna trimmer adjusted for best reception. The set was now performing quite satisfactorily although like most sets of that era, the RF transistor isn’t exactly quiet. As a result, the set is a bit “hissy” on the weaker stations. distortion but I still felt that there was something wrong with the output stage. Next, I checked the voltages on the collectors of the 2N217S and they were nearly identical (ie, with the set delivering a reasonable volume). I then fed a 1kHz modulated signal from a signal generator into the set and checked the voltages across R28 and R29. They varied equally with increased volume but there was still noticeable distortion. The old CRO The original 2364 battery type used in the B29 is no longer available but six AA cells in a holder can be used instead. 102 Silicon Chip It was time to bring out the heavy artillery, so I fired up my CRO to track down the source of this distortion. This showed that the audio was a beautiful sinewave up to the bases of the 2N217S output transistors but when I put the probe onto either collector, I got a horrible looking waveform. I had expected to see a half sinewave but that wasn’t the case. I then tried disabling one half of the output stage siliconchip.com.au by getting rid of the signal alternatively to each base but it still looked terrible and I was getting nowhere fast! My next step was to use the dual inputs of the CRO. By placing a probe onto each section of the output, I could observe the phasing of the output stage. It still looked terrible but at least the two waveforms showed that the problem occurred in each transistor output on each half wave. I then decided to use the add function and what did I see? – a beautiful sinewave. I’d been trapped by the rather unusual nature of the circuit. If the speaker had been fed from a centretapped transformer, the CRO would have shown a sinewave on the voice coil. However, the system used in this set is different, as the output goes to a centre tapped choke (ie, the speaker) and the waveforms are different. So what was causing the distortion? If I’d thought about it, I would have realised what the answer was – this is a personal portable with low-output transistors feeding the speaker so I was really expecting too much of the audio stage. Putting it back together Having solved that problem, it was now time to reassemble the receiver. I won’t go into all the problems I ran into but it took me no less than 20 minutes to do the job. By contrast, I remember when the local film processing laboratory was giving a radio away with each film developed. These radios must have cost them next to nothing but they were still rather nice little 5-transistor sets. And they could be dismantled and reassembled in about one minute! That said, the fully assembled B29 now looks good and performs quite credibly. And with an external antenna and earth, it really works very well indeed. Substitute battery Type 2364 batteries are now unobtainable, so I decided to see if six Ccells could be fitted into the receiver’s case. Unfortunately, the holder was just a little too large but a pack of six AA-cells in a holder can be fitted and will give reasonable life. It is only necessary to solder a battery snap lead to the 2364 battery plug and the B29 is ready to use as a portable. To prevent any shorts, a couple of pieces of plastic tubing were placed siliconchip.com.au Photo Gallery: Precedent 5-Valve Receiver Designed and manufactured by Firth Brothers, Melbourne, the Precedent c1933 was a stylish table model receiver that tuned the medium-wave band. The valves fitted were as follows: 57 autodyne mixer; 58 IF amplifier; 57 anode bend detector; 2A5 audio output; and 80 rectifier. Photo: Historical Radio Society of Australia, Inc. over the exposed lugs on the 2364 battery plug. The 6-cell pack fits snugly inside the case, as can be seen in the photograph. Summary The B29 is quite a nice little set, rather typical of many sets of the same era. Its performance is good (although the audio suffers as the battery voltage drops) and the handspan dial system works well. In summary, it is a pleasant little transistor set which I’m quite pleased SC to have in my collection. A Few Gremlins A few gremlins crept into the April 2005 column, as follows: (1) Page 80, third column, end of paragraph four should read: “This feeds one section of a 6SN7-GT as the second stage, while the second section acts as a phase splitter . . .” (2) The AGC bypass capacitor at the extreme left of the circuit (Fig.1) should be 47nF not 47µF. (3) The asterisks marking the com- ponents replaced were omitted. The components replaced were: all the electrolytic capacitors, the AGC and audio coupling capacitors (except the coupler to the grid of V7), the screen dropping resistor feeding the 6U7-G valves and the accompanying screen bypass capacitor. (4) V4’s cathode should be earthed and not connected to the 25kW resistor, volume control or the 100pF capacitor. The same error is on the amended AGC circuit (Fig.3). May 2005 103 ASK SILICON CHIP Got a technical problem? Can’t understand a piece of jargon or some technical principle? Drop us a line and we’ll answer your question. Write to: Ask Silicon Chip, PO Box 139, Collaroy Beach, NSW 2097; or send an email to silchip<at>siliconchip.com.au Deep-cycle batteries explained I am confused by your charger article in the November 2004 issue, referring to “deep-cycle” batteries. I am familiar with ordinary old-fashioned lead-acid batteries and sealed lead-acid (SLA) or Gel-Cell batteries, both of which have been around for many years. I have purchased a new battery for my golf buggy; 12V, 24A.h SLA. Its charger is a simple voltage-sensing device that cuts back to a trickle when the battery has reached a pre-determined voltage. When I asked about “deepcycle” batteries the salesman looked at me blankly. So exactly what are they? (G. H., via email). • Deep-cycle batteries are made to be discharged down to a certain level before charging. They have a different chemical make-up to standard (car) batteries that are designed for only a shallow discharge. SLA batteries used in golf carts would be a deep-cycle type since they can be discharged below 20% of their capacity before charging. Signal problem with boost controller I have just bought some of your new automotive kits from the “Performance Electronics for Cars” book. They are the Fuel Controller and Independent Boost Controller. I would like to use the boost controller to control a diesel injection pump (to control boost pressure to the fuel enrichment diaphragm). The problem is that the boost controller relies on a duty cycle signal. In a diesel I don’t have that option. Could I fit an analog to digital converter between a boost pressure sensor and boost controller to change the signal? I like the new kits; easy to assemble, with well-written directions. (B. G., Napier, NZ). • Sorry, the input needs to be a duty cycle signal. An analog to digital converter does not do the same job. MP3 Player startup fix If you’ve built the remote control MP3 player featured in the September & October 2001 issues of SILICON CHIP, you may find that the LCD displays “garbage” characters every time you power up your PC. This is caused by Windows querying the port for a serial mouse as it starts. If you’re a seasoned microcontroller programmer, you can change the “startup delay” parameter stored in EEPROM to stop this from happening. However, a much simpler solution is to send a string of characters to the LCD display to clear it (or display a message) each time Windows starts. We’ve created a simple DOS batch file, called LCDMSG.BAT, that does just that. It contains only two lines; the first initialises the serial port, 104 Silicon Chip and the second sends the contents of the text file LCDMSG.TXT to that port. You can edit the file with any text editor (eg, Notepad) to change the COM port number to suit your system. You can also edit LCDMSG.TXT in order to display any custom message that you like. Don’t edit or delete the first few characters though; they’re embedded control codes that are used to clear the LCD display. CLEARLCD.ZIP contains both of the above mentioned files and can be downloaded from the SILICON CHIP website at www.siliconchip. com.au. Simply unzip it into your C:\Program Files\IRRemote directory and placed a shortcut to C:\ Program Files\IRRemote\LCDMSG. BAT in your Startup folder. A voltage to duty cycle inverter is what you would need. Similar designs for this include pulse width modulation using the TL494. Large screen scope wanted Did you ever do any projects on building an oscilloscope or a frontend unit that plugs into a TV for that purpose? (M. M., Mossel Bay, South Africa). • We have not done a project along the lines you describe. A better approach is to use our Sound Card Interface from the August 2002 issue and team it up with oscilloscope software to use with your PC (details in the same issue). False Triggering Smoke Alarm Control Panel I have bought two Smoke Alarm Control Panel kits, as described the January & February 1997 issues. The first I assembled in April 1998, using five Kambrook SD29 Smoke Detectors. This has been in continuous use ever since and generally very satisfactory. The regulated supply to the detectors has been checked several times and is always about 8.9V and the battery float voltage always indicates close to fully charged. We have been very concerned with periodic false alarms with the second unit. These are not due to any smoke, visible or invisible, nor vapours from kitchen or bathroom. The system can operate for months without any action but then typically in the early morning hours, say about 4AM, or it could occur in the middle of the evening or even during the daytime, one detector will emit very brief ‘pips’ or weak ‘beeps’ for a few seconds and then may cease or do the same after a short while, or again it may go on to full alarm output and set off all the others (as it should). This behaviour seems to occur siliconchip.com.au about October or November. We have guessed that it may be caused by pollen in the air. Do you think this is possible and have you received any other complaints of strange behaviour? (R. B., Flaxton, Qld). • It is possible that one of your smoke detectors is too sensitive. Perhaps your detectors could be checked using a candle or similar to determine if one of them is too sensitive. Alternatively, one of the smoke detectors could be faulty. Controlling a Peltier tile I’m looking at operating a Peltier function tile via a parallel port connection to my PC. My intention is to drive the tile and record feedback of temperature variations. Are there any kits available that will enable me to do this. Any additional advice would be much appreciated. (F. E., via email). • If you only need 8-bit accuracy for the temperature measurements, then the Parallel Port I/O Card published in January 2000 might be suitable (DSE cat K-2805). You will need to design your own circuit to interface between the card’s open-collector outputs and the power switching circuit for the tile. The same goes for the analog input, where you’ll probably need a buffer circuit for the temperature sensor. Alternatively, check out the USB I/O 24 card from Elexol (Phone 07 5574 3988). It supports the DS18B20 direct-to-digital temperature sensor, so no additional circuitry will be required on the input side. 2-channel guitar preamp problems I have built the 2-channel guitar preamp from your November 2000 issue, with varying success. The preamp sounds great but the treble control doesn’t work on either channel. Also I cannot get the digital reverb board to work. All the input voltages are correct and the polarities are correct, according to the testing section of the article. I was hoping for a direction to look in and whether the two problems are related? (A. S., via email). • Treble control and reverb operation are unrelated. Make sure the correct value components are used for this siliconchip.com.au SMS Controller voltage tolerance I’m trying to build the SMS controller featured in your October & November 2004 issues and I’ve purchased the Jaycar kit (KC-5400) to do so. I’ve completed assembly and have started to follow the checkout procedure in part 1. Along the way I’ve discovered some problems. The +5V checks are all good. I have problems, however, with the phone supply section. Unloaded, the phone supply gives 7.1V (article says 7.0V) but loaded with the 10W 5W resister, I get 4.2-4.3V instead of the desired 3.6-3.9V. Is this too much? I have checked out my parts placement and believe it to be correct but I’ve noticed the following: (a) the two 1.5W resisters are within 5% (correct) but when wired in parallel and measured, the “on board” resistance is 0.9W, not 0 .75W. Is this an issue? (b) Jaycar have substituted a 220mH 5A ferrite choke for L1. Part size and placement aside, would this cause changes to voltages? (c) IC5 is supposed to be an MC34063. I assume “MC” is for Motorola? The kit includes a chip with the following designations for IC5: ST - brand? CHN - country of origin [China]? 063EB - part number? K12129 - batch? Is this replacement suitable? At this point, I’m am at a loss as to what to do next. Any suggestions would be greatly received. (G. W., Auckland, NZ). control (ie, the pot and capacitor in series with the potentiometer wiper). The Reverb unit may have a bad solder connection on the PC board or an incorrect component. Recheck the PC board for shorts between tracks or breaks in the tracks. Charging SLA batteries in a car I hope you can help me with information on charging SLA (sealed lead-acid) batteries. I want to charge and use an SLA battery in my car to run accessories when the car is turned off. My car runs at 14V which I believe will charge the battery whilst the car • The answers to your questions are as follows: (a) two 1.5W 5% resistors in parallel should measure between 0.712W and 0.787W. You either have a faulty resistor or your multimeter is not accurate enough to measure these low resistances (many are not). Also note that in-circuit measurements can be misleading. (b) the physically larger Jaycar choke won’t alter the output voltage. (c) the “MC” prefix is for Motorola (now On Semiconductor). “ST” is for ST Microelectronics, whom we assume are a second source for the original part. So yes, it should be OK. The higher voltage is most likely due to tolerances in the peak voltage sensing of the 34063, as well as in the 1.5W resistors and even the 10W test resistor. It is quite normal for the output voltage to change when the input voltage is varied. This is because the circuit is limiting peak current (not regulating voltage) once the output drops below about 7V. The voltage under load is higher than we would have anticipated (meaning slightly higher charging current to the phone) but it is still within operating parameters. You can safely use it as is. Alternatively, you can reduce the charge current back below 400mA by replacing one of the 1.5W resistors with a value of 1.8W. is running. Is there a maximum time I should leave the battery on charge? My understanding is that it would be OK to leave it connected as it would act like a second car battery and as the battery reaches 14V, it will stop excepting charge. Is this true? (S. B., via email). • Charging an SLA battery in parallel with a car battery presents problems. Normally, you should not exceed 13.8V across an SLA whereas car batteries can be charged to over 14V. Connecting an isolating diode is also necessary otherwise the SLA battery will be subject to heavy discharge while you are starting the vehicle. However, an isolating diode will also May 2005 105 mean that the SLA battery is unlikely to be charged much above 13.5V (if you’re lucky) so it will never be charged properly. You also need to make sure that the SLA battery is never discharged below about 11V otherwise it will be destroyed. We suggest you consider building the Adjustable DC-DC Converter for Cars, published in the June 2003 issue. This can be set to charge SLA batteries. 50MHz frequency meter display problem I have purchased a 50MHz Frequency Meter kit (SILICON CHIP, October 2003) from Dick Smith Electronics (Cat K7001). I need to purchase several ICs as replacement items. These are the MC10116P triple ECL differential line receiver, the 74HC132 quad Schmitt trigger and the PIC16F84-20P programmed microcontroller. Do you have a contact where I can purchase these items. I would dearly appreciate your assistance with this so I can get my project up and running. My problem is that the LCD only displays one segment during the initial setup testing procedure instead of “0 Hz”. I have triple checked all the components for correct type, location and orientation but still have no joy. Any assistance you could provide me would be terrific. (C. W., via email). • The ICs are unlikely to be faulty. If they are, you can get replacements from the DSE kit department. Probably the fault is a short between tracks or a broken connection somewhere. Class-A headphone amplifier wanted Back in 1998 you designed a 15W class-A amplifier and Altronics still sells it (Cat K5109). I’ve been using one for quite a while now and I have spare amp modules. I was interested to know if these amps could be modified just to run headphones. I have been building amplifiers for a while now. I started with the ETI-5000 and even tried your 100W Ultra-LD amplifier and others but none quite sings like your class-A design. I found a dedicated headphone classA amplifier on http://headwize.com/ projects/showfile.php?file=gilmore3_ prj.htm but the PC board design leaves 106 Silicon Chip a lot to be desired and is overly complicated for class-A. Your PC boards are very well laid out. Any suggestions would be greatly appreciated. (A. W., via email). • You could certainly modify the 15W class-A modules to drive headphones although they could drive them unmodified, of course. If you just wanted to drive headphones, the quiescent current could be dropped to 100mA and you could substitute cheaper output transistors such as TIP2955 and TIP3055, as used in the SC480 modules. With the reduction in output stage power dissipation to around 4W per channel you can use much smaller heatsinks and a transformer with a much lower power rating could be substituted. Note that we have not done any of these mods. More detail wanted on kit projects I’ve been buying SILICON CHIP magazine for about two years now, with the main intention of teaching myself electronics. To this end, I found the Prawnlight project in the January 2005 issue a little light on detail. For a while I had trouble working out why the transistors were necessary and why just resistors alone would not suffice. I ended up concluding that the three diodes were used specifically for their known 0.7V voltage drop to provide a 2.1V reference voltage for the base of Q17 so that the LEDs don’t gradually dim as the battery is depleted. Is this correct? The purpose of the two capacitors has me totally stumped. What I found really disappointing was the lack of detail about the LEDs, and the fact that I could not find any data on C8050 transistors in the data section of the Dick Smith Electronics catalog. This effectively rules out anyone using their “junk box” to source parts. (T. L., via email). • As stated in the article on page 67, the circuit uses constant current drivers. This is so that the LEDS don’t dim as the battery discharges. Q17 provides a voltage reference to the bases of all driver transistors, so that they do operate as constant current sources. You could use any white LEDs; the brighter, the better. The two capacitors are included as a stability measure. Without them, there is a possibility that Q17, which is configured as an emitter follower, could oscillate supersonically. It is not well known that emitter followers can oscillate but it is quite common if these precautions are not taken. The C8050 are general purpose NPN transistors. You could substitute almost anything: BC548, BC338, PN100 etc. Just watch the pinouts. We do try to include a lot of circuit detail in our articles but it is not possible to include all the circuit incidentals in every article. If we did, the magazine would be twice the size. Reluctor ignition misses at idle I built your High Energy Ignition kit (SILICON CHIP, June 1998) and have had it connected to a points-style system without any problems. I have now upgraded to a reluctor style ignition system which worked fine using the factory igniter until recently when it died. The igniter is $160+ new, so obviously I wanted a cheaper way out of the problem with the same or better performance. I have now converted the HEI kit to the reluctor circuit, taking out the points components and have checked the circuit many times. The circuit works fine and the car has awesome performance up in the high revs but it misses at idle speed. The spark plugs, HT leads and distributor cap etc are all new and there is no missing above 1500 RPM but the car hardly idles. Would this have anything to do with the sensitivity of the reluctor circuit as it needs to reach a certain speed before the reluctor outputs enough volts to fire correctly? (D. S., via email). • The sensitivity of the reluctor circuit can be improved by varying the 47kW resistor connected to the cathode of ZD5. Substitute a 200kW trimpot and adjust it so that the circuit works at idle. Then replace it with a fixed resistor of the same value. Clifford cricket diode confusion We recently assembled Clifford the Electronic Cricket (SILICON CHIP, December 1994). It had its moments and we just about got there in the end. Well, almost. The problem is that once the battery is connected, siliconchip.com.au although Clifford does his chirping bit correctly, his eyes stay on all the time. Could this have something to do with the orientation of the diodes? It is rather confusing but everything we have read on the internet (including the diode’s product manual!) states that the cathode end of the diode is the one with the stripe. The diagram says to place the “A” anode end near the 3.3kW resistor but in an earlier post on your website regarding Clifford, you state “The anode (A) is the end of the diode with the stripe. Both anodes for D1 and D2 should be toward the 3.3kW resistor” which would mean that ours is theoretically the wrong way around. Which way should it be? We would love to get it working fully. (S. J., via email). • The cathode is the striped end of a diode. On Clifford, the cathodes for both diodes D1 and D2 are oriented toward the 470kW resistor. The anodes are toward the 3.3kW resistor, as marked on the PC board component overlay diagram. arrangement but with slightly more ripple and current capability than one would expect with a secondary winding tapped at the centre. My question is this. If I use large filter capacitors (eg, two 22,000mF 50V lowESR electrolytics), will there be much degradation in the amplifier’s performance? My suspicion is that there will be a measurable but inaudible degradation, but I would be interested to hear the views of the experts at SILICON CHIP. (B. K., via email). • Our guess is that the transformer will supply around ±46V but the higher voltage section (33VAC) will do most of the work. Also you will have a high component of 50Hz ripple rather than the normal 100Hz. The amplifier will still work although it might have higher hum than if the correct supply was used. Apart from that, we would expect no degradation in performance. Non-centre-tapped transformers will work How much does it cost to run a ceiling fan, eg, flat out all day. (G. C, Brisbane, Qld). • It depends on the fan’s power rating and your power tariff. If we assume your fan pulls 200W when going flat out, it will then use 4.8kWh in a 24hour day. Multiply this by your power tariff of say, 12 cents a kilowatt-hour (you will find the tariff on your power bill) and the answer is 48 cents. That’s a lot less than running an air conditioner. I recently bought a pair of very well-made 300VA transformers with multi-tapped 64V secondaries, intending to use them in high-quality audio amplifiers (ETI488 modules, which I prefer over all others) which need a ±45V DC supply rail. However, it turns out that there is no AC centre tap on the transformers: the closest is at 31/33V AC on the secondary. At first, I was inclined to reject the transformers as being unsuitable for my application but on reflection, I realise that they will in fact deliver ±45V DC in a conventional bridge rectifier Ceiling fan power consumption Active crossover question I have purchased the Jaycar Active Notes & Errata PICAXE Freezer Thermostat (Circuit Notebook, March 2005): The serial programming input (pin 2) and output (pin 7) for IC1 (page 73) are shown connected in reverse. crossover kit which was published in your magazine in January 2003. If I understand correctly, all resistors which are 10kW and 20kW and all capacitors which are 2.2nF and 47nF need to be changed in order to set crossover frequencies. There appears to be one exception – the 10kW resistor on the input. Could you please confirm if this is correct? I have looked carefully through the article and instructions provided with the kit and can’t find information on exactly which resistors and capacitors need to be changed for different crossover frequencies. Only a few of them are nominated as C, 2C, R, & 2R which need to be changed. It is clear that many others need to be changed as well but it’s not possible to tell which ones based on the information given. In fact, there are quite a few which I’m not sure should be changed. This is misleading as some may just change the values you have marked! (P. S., via email). • IC1a is an input buffer and its 10kW input resistor does not need to change. Depending on which crossover frequencies you want to change, the relevant 10kW, 20kW, 2.2nF and 47nF values need to change. For example, if you want to change the LP (low pass) frequency, you need to change the relevant resistors and capacitors associated with IC5d & IC5c. SC WARNING! SILICON CHIP magazine regularly describes projects which employ a mains power supply or produce high voltage. All such projects should be considered dangerous or even lethal if not used safely. Readers are warned that high voltage wiring should be carried out according to the instructions in the articles. When working on these projects use extreme care to ensure that you do not accidentally come into contact with mains AC voltages or high voltage DC. If you are not confident about working with projects employing mains voltages or other high voltages, you are advised not to attempt work on them. Silicon Chip Publications Pty Ltd disclaims any liability for damages should anyone be killed or injured while working on a project or circuit described in any issue of SILICON CHIP magazine. Devices or circuits described in SILICON CHIP may be covered by patents. SILICON CHIP disclaims any liability for the infringement of such patents by the manufacturing or selling of any such equipment. SILICON CHIP also disclaims any liability for projects which are used in such a way as to infringe relevant government regulations and by-laws. Advertisers are warned that they are responsible for the content of all advertisements and that they must conform to the Trade Practices Act 1974 or as subsequently amended and to any governmental regulations which are applicable. siliconchip.com.au May 2005 107 THE AMATEUR SCIENTIST Two incredible CDs with over 1000 classic projects from the pages of Scientific American, covering every field of science... Arguably THE most IMPORTANT collection of scientific projects ever put together! This is version 2, Science Fair Edition from the pages of Scientific American. As well as specific project material, the CDs contain hints and tips by experienced amateur scientists, details on building science apparatus, a large database of chemicals and so much more. “A must for every science student, science teacher, science lab . . . or simply for those with an enquiring mind . . .” ONLY 49 $ 00 PLUS $7 Pack and Post within Australia (Overseas orders: please refer to Page 91 of this issue) Just a tiny selection of the incredible range of projects: ! Build a seismograph to study earthquakes ! Make soap bubbles that last for months ! Monitor the health of local streams ! Preserve biological specimens ! Build a carbon dioxide laser ! Grow bacteria cultures safely at home ! Build a ripple tank to study wave phenomena ! Discover how plants grow in low gravity ! Do strange experiments with sound ! Use a hot wire to study the crystal structure of steel ! Extract and purify DNA in your kitchen !Create a laser hologram ! Study variable stars like a pro ! Investigate vortexes in water ! Cultivate slime moulds ! Study the flight efficiency of soaring birds ! How to make an Electret ! Construct fluid lenses ! Raise butterflies as experimental animals ! Study the physics of spinning tops ! Build an apparatus for studying chaotic systems ! Detect metals in air, liquids, or solids ! Photograph an ant's brain and nervous system ! Use magnets to make fluids into solids ! Measure the metabolism of an insect . . . ! and many, many more (a thousand more, in fact!) See the review in SILICON CHIP, October 2004. . . or read on line at www.siliconchip.com.au HERE’S HOW TO ORDER YOUR COPY: BY MAIL:# BY INTERNET:^ BY PHONE:* (02) 9979 5644 9-4 Mon-Fri BY FAX:# (02) 9979 6503 24 Hours 7 Days <at> BY EMAIL:# silchip<at>siliconchip.com.au 24 Hours 7 Days PO Box 139, Collaroy NSW 2097 * Please have your credit card handy! # Don’t forget to include your name, address, phone no and credit card details. siliconchip.com.au 24 Hours 7 Days ^ You will be prompted for required information There’s also a handy order form on page 91 of this issue (SILICON CHIP Bookshop pages). Exclusive in SILICON Australia to: CHIP www.siliconchip.com.au 108 Silicon Chip siliconchip.com.au MARKET CENTRE Cash in your surplus gear. Advertise it here in Silicon Chip. FOR SALE MORE ELECTRONIC CONTROL SPECIALS FOR YOU: New – Novus Signal Conditioners both non-isolated and isolated Convert thermocouples, RTDs to 4-20mA or 0-10V Fully programmable. New – Netiom Ethernet and Web I/O monitor and control I/O on the web and generate alarm emails New – Labjack Ethernet/USB Data Acquisition Module features 14 16bit analog inputs, 23 digital I/O, 2 analog outputs and 2 high speed counter. Free software, Labview driver and ActiveX component. Counter and Timers – 7-digit and battery operated Proximity and Photoelectric sensors Temperature and humidity sensors N1500 universal process indicator. Budget priced displays thermocouple, RTD, 4-20mA and 0-5V readings. Fully programmable UHF 433MHz and InfraRed remote relay controller cards Serial and Parallel port relay controller cards Pump and Trip Alarm Controller card. MicroProgrammers for Atmel and PIC chips. 2, 4 & 8 Relay Cards suitable for TTL and Open Collector Outputs DC, Stepper and Servo Motor controller kits Switch Mode and Linear Power Supplies and DC-DC converters. Full details and credit card ordering available at www.oceancontrols.com.au Helping to put you in control. RCS RADIO/DESIGN is at 41 Arlewis St, Chester Hill 2162, NSW Australia and has all the published PC boards from SC, EA, ETI, HE, AEM & others. Ph (02) 9738 0330. sales<at>rcsradio. com.au, www.rcsradio.com.au PCBs MADE, ONE OR MANY. Any format, hobbyists welcome. Sesame Electronics Phone (02) 9593 1025. sesame<at>sesame.com.au www.sesame.com.au siliconchip.com.au CLASSIFIED ADVERTISING RATES Advertising rates for this page: Classified ads: $22.00 (incl. GST) for up to 20 words plus 66 cents for each additional word. Display ads: $36.00 (incl. GST) per column centimetre (max. 10cm). Closing date: five weeks prior to month of sale. To run your classified ad, print it clearly in the space below or on a separate sheet of paper, fill out the form & send it with your cheque or credit card details to: Silicon Chip Classifieds, PO Box 139, Collaroy, NSW 2097. Alternatively, fax the details to (02) 9979 6503 or send an email to silchip<at>siliconchip.com.au Taxation Invoice ABN 49 003 205 490 _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ Enclosed is my cheque/money order for $__________ or please debit my  Bankcard  Visa Card  Master Card Card No. Signature__________________________ Card expiry date______/______ Name _____________________________________________________ Street _____________________________________________________ Suburb/town ___________________________ Postcode______________ Phone:_____________ Fax:_____________ Email:__________________ May 2005 109 ELECTRONIC DESIGN Want cost-effective, professional design expertise “on call”, without having to employ new staff? Use ours! 4D Systems have extensive experience in hardware & software design, from component through to entire project. We will take your ideas from concept to completion, on time and on budget. Digital, analog, software: whatever your requirements, 4D Systems can do it! 4D Systems TAIG MACHINERY Micro Mini Lathes and Mills From $489.00 Wi-Fi 2.4GHz Antennas Directionals Omnis Stepper motors: 200 oz in $89.00, 330 oz in $110.00 Digital verniers: 150mm $55.00, 200mm $65.00 59 Gilmore Crescent (02) 6281 5660 Garran ACT 2605 0412269707 We also stock: Panel Antennas Ceiling Antennas Low-loss 50 Ω cable Connectors Pigtails Access Points Masts Amplifiers Power-over-Ethernet External Enclosures Everything you need for WiFi! (02) 9673 2228 0433 198 874 Select your microcontroller kit and get started... Fax a copy of From $295* RCM3400 this ad and receive a 5% discount on your order! Feature rich, compiler, editor & debugger with royalty free TCP/IP stack Foam surrounds,voice coils,cones and more Original parts for Dynaudio,Tannoy and others Expert speaker repairs – 20 years experience Australian agents for products Trade welcome – email for your user ID Phone (03) 9647 7000 speakerbits.com.au FREENET-ANTENNAS Web: www.freenet-antennas.com Email: sales<at>freenet-antennas.com Tel: (08) 9319 3275 (int +618 9319 3275) Fax: (08) 9319 1720 (int +618 9319 1720) • Prices exclude GST and delivery charges. Tel: + 61 2 9906 6988 Fax: + 61 2 9906 7145 www.dominion.net.au 4007 S-Video . . . Video . . . Audio . . . VGA distribution amps, splitters, standards converters, tbc’s, switchers, cables, etc, & price list: www.questronix.com.au WEATHER STATIONS: windspeed & direction, inside temperature, outside temperature & windchill. Records highs & lows with time and date as they occur. Optional rainfall and PC interface. Used by government departments, farmers, pilots and weather enthusiasts. Other models with barometric pressure, humidity, dew point, solar radiation, UV, leaf wetness, etc. Just phone, fax or write for our FREE catalog and price list. Eco Watch phone: (03) 9761 7040; fax: (03) 9761 7050; Unit 5, 17 Southfork Drive, Kilsyth, Vic. 3137. ABN 63 006 399 480. ELECTRONIC ENGINEERING CONSULTANTS: Electronic Hardware and Embedded Software for Industrial Control and Commercial Communications. www.furzy.com.au USB KITS: GPIB Interface, Thermostat Tester, LCD Module Interface, Stepper Motor Controller, PIO Interface, DTMF Transceiver, Thermometer, DDS HF Generator, Compass, 4 Channel Voltmeter, I/O Relay Card, USB via 110 Silicon Chip Satellite TV Reception International satellite TV reception in your home is now affordable. Send for your free info pack containing equipment catalog, satellite lists, etc or call for appointment to view. We can display all satellites from 76.5° to 180°. AV-COMM P/L, 24/9 Powells Rd, Brookvale, NSW 2100. Tel: 02 9939 4377 or 9939 4378. Fax: 9939 4376; www.avcomm.com.au New New New Mark22-SM Slimline Mini FM R/C Receiver • • • • • 6 Channels 10kHz frequency separation Size: 55 x 23 x 20mm Weight: 25gm Modular Construction Price: $A129.50 with crystal Electronics PO Box 580, Riverwood, NSW 2210. Ph/Fax (02) 9533 3517 email: youngbob<at>silvertone.com.au Website: www.silvertone.com.au LabVIEW. Also available: Digital Oscilloscope, Temperature Loggers, VHF Receivers and USB ActiveX (and USBDOS.exe file) to control our kits from your own application. www.ar.com. au/~softmark SUPERBRIGHT LEDS from just 8 cents each! 25mm dia. spiral neon tubes $15 each. New 6-digit nixie clock/ panel meter kit! IO Moon 1.5 watt LEDs, uranium glass marbles, RGB superflux LEDs, and lots of other neat stuff. www. ledsales.com.au PCB DESIGN Service/Project Development: Project design from your concept; PCB design – single & multilayer; siliconchip.com.au Do You Eat, Breathe and Sleep TECHNOLOGY? Opportunities for full-time and part-time positions all over Australia & New Zealand Jaycar Electronics is a rapidly growing, Australian owned, international retailer with more than 39 stores in Australia and New Zealand. Our aggressive expansion programme has resulted in the need for dedicated individuals to join our team to assist us in achieving our goals. We pride ourselves on the technical knowledge of our staff. Do you think that the following statements describe you? Please put a tick in the boxes that do: Knowledge of electronics, particularly at component level. Assemble projects or kits yourself for car, computer, audio, etc. Have empathy with others who have the same interest as you. May have worked in some retail already (not obligatory). Have energy, enthusiasm and a personality that enjoys helping people. Appreciates an opportunity for future advancement. Have an eye for detail. Why not do something you love and get paid for it? Please write or email us with your details, along with your C.V. and any qualifications you may have. We pay a competitive salary, sales commissions and have great benefits like a liberal staff purchase policy. Send to: Retail Operations Manager - Jaycar Electronics Pty Ltd P.O. Box 6424 Silverwater NSW 1811 Email: jobs<at>jaycar.com.au Jaycar Electronics is an equal opportunity employer and actively promotes staff from within the organisation. Advertising Index 4D Systems................................110 Amateur Scientist CD ................108 Altronics................................. 78-81 ATA...............................................37 Av-Comm...................................110 Dick Smith Electronics........... 22-27 Dominion Electronics...........75, 110 Elexol...........................................51 Evatco........................................101 Circuits professionally drawn; Instruction/Operation Manuals prepared; PIC software design/modification/programming; Prototypes constructed. Email: media.audio<at>optusnet.com.au Phone: 0414 356 409. ImageCraft C Compilers: 32-bit Windows IDE and compiler. For AVR, 68HC08, 68HC11, 68HC12, 68HC16. from $330.00 Atmel Flash CPU Programmer: Handles the 89Cx051, 89C5x, 89Sxx in both DIP and PLCC44 and some AVR’s, most 8-pin EEPROMS. Includes socket for serial ISP cable. $220, $11 p&p. SOIC adaptors: 20 pin $132.00, 14 pin $126.50, 8 pin $121.00. Full details on web site. Credit cards accepted. GRANTRONICS PTY LTD, PO Box 275, Wentworthville 2145. (02) 9896 7150 or http://www.grantronics.com.au WANTED WANTED: EARLY HIFIs, AMPLIFIERS, Speakers, Turntables, Valves, Books, Quad, Leak, Pye, Lowther, ELNEC IC PROGRAMMERS Freenet Antennas.......................110 Universal and specialised models High quality Realistic prices Large range of adaptors Free regular software updates Windows 95/98/Me/NT/2k/XP Grantronics.................................111 GRANTRONICS PTY LTD PO Box 275, Wentworthville. 2145. Ph: 02 9896 7150 www.grantronics.com.au Hy-Q International........................83 Instant PCBs..............................111 Jaycar ...............IFC, 53-60, 83, 111 JED Microprocessors...............5, 83 Microgram Computers....................3 MicroZed Computers....................51 National Instruments....................39 Ortofon, SME, Western Electric, Altec, Marantz, McIntosh, Goodmans, Wharfedale, Tannoy, radio and wireless. Collector/Hobbyist will pay cash. (02) 9440 1267. johnmurt<at>highprofile. com.au WANTED: ETI Jan-Dec 1980. Ph 03 5341 7604. Fax 03 5341 7904. KIT ASSEMBLY NEVILLE WALKER KIT ASSEMBLY & REPAIR: • Australia wide service • Small production runs • Specialist “one-off” applications Phone Neville Walker (07) 3857 2752 Email: flashdog<at>optusnet.com.au Circuit & Design Ideas Wanted Do you have a good circuit idea? If so, sketch it out, write a brief description of its operation & send it to us. Provided your idea is workable & original, we’ll publish it in Circuit Notebook & you’ll make some money. We pay up to $60 for a good circuit so send your idea to: Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. siliconchip.com.au Harbuch Electronics.....................83 Oatley Electronics........................85 Ozitronics.....................................75 Prime Electronics...........................7 Quest Electronics.................83, 110 RCS Radio.................................111 RF Probes..................................103 Silicon Chip Binders.....................74 Silicon Chip Bookshop.......112, IBC Silicon Chip Subscriptions...........61 Silvertone Electronics................110 Siomar Batteries..........................67 Speakerbits................................110 Taig Machinery...........................110 Telelink.........................................83 VAF Australia ...........................OBC ____________________________ PC Boards Printed circuit boards for SILICON CHIP projects are made by: RCS Radio Pty Ltd. Phone (02) 9738 0330. Fax (02) 9738 0334. May 2005 111 ALL S ILICON C HIP SUBSCRIBERS – PRINT, OR BOTH – AUTOMATICALLY QUALIFY FOR A REFERENCE $ave 10%ONLINE DISCOUNT ON ALL BOOK OR PARTSHOP PURCHASES. CHIP BOOKSHOP 10% (Does not apply to subscriptions) SILICON For the latest titles and information, please refer to our website books page: www.siliconchip.com.au/Shop/Books PIC MICROCONTROLLERS: know it all SELF ON AUDIO Multiple authors $85.00 The best of subjects Newnes authors have written over the past few years, combined in a one-stop maxi reference. Covers introduction to PICs and their programming in Assembly, PICBASIC, MBASIC & C. 900+ pages. PROGRAMMING and CUSTOMIZING THE PICAXE By David Lincoln (2nd Ed, 2011) $65.00* A great aid when wrestling with applications for the PICAXE See series of microcontrollers, at beginner, intermediate and Review April advanced levels. Every electronics class, school and library should have a copy, along with anyone who works with PICAXEs. 300 pages in paperback. 2011 PIC IN PRACTICE by D W Smith. 2nd Edition - published 2006 $60.00* Based on popular short courses on the PIC, for professionals, students and teachers. Can be used at a variety of levels. An ideal introduction to the world of microcontrollers. 255 pages in paperback. PIC MICROCONTROLLER – your personal introductory course By John Morton 3rd edition 2005. $60.00* A unique and practical guide to getting up and running with the PIC. It assumes no knowledge of microcontrollers – ideal introduction for students, teachers, technicians and electronics enthusiasts. Revised 3rd edition focuses entirely on re-programmable flash PICs such as 16F54, 16F84 12F508 and 12F675. 226 pages in paperback. by Douglas Self 2nd Edition 2006 $69.00* A collection of 35 classic magazine articles offering a dependable methodology for designing audio power amplifiers to improve performance at every point without significantly increasing cost. Includes compressors/limiters, hybrid bipolar/FET amps, electronic switching and more. 467 pages in paperback. SMALL SIGNAL AUDIO DESIGN By Douglas Self – First Edition 2010 $95.00* The latest from the Guru of audio. Explains audio concepts in easy-to-understand language with plenty of examples and reasoning. Inspiration for audio designers, superb background for audio enthusiasts and especially where it comes to component peculiarities and limitations. Expensive? Yes. Value for money? YES! Highly recommended. 558 pages in paperback. AUDIO POWER AMPLIFIER DESIGN HANDBOOK by Douglas Self – 5th Edition 2009 $85.00* "The Bible" on audio power amplifiers. Many revisions and updates to the previous edition and now has an extra three chapters covering Class XD, Power Amp Input Systems and Input Processing and Auxiliarly Subsystems. Not cheap and not a book for the beginner but if you want the best reference on Audio Power Amps, you want this one! 463 pages in paperback. DVD PLAYERS AND DRIVES by K.F. Ibrahim. Published 2003. $71.00* OP AMPS FOR EVERYONE By Bruce Carter – 4th Edition 2013 $83.00* This is the bible for anyone designing op amp circuits and you don't have to be an engineer to get the most out of it. It is written in simple language but gives lots of in-depth info, bridging the gap between the theoretical and the practical. 281 pages, A guide to DVD technology and applications, with particular focus on design issues and pitfalls, maintenance and repair. Ideal for engineers, technicians, students of consumer electronics and sales and installation staff. 319 pages in paperback. by Sanjaya Maniktala, Published April 2012. $83.00 Thoroughly revised! The most comprehensive study available of theoretical and practical aspects of controlling and measuring EMI in switching power supplies. Subtitled Exploring the PIC32, a Microchip insider tells all on this powerful PIC! Focuses on examples and exercises that show how to solve common, real-world design problems quickly. Includes handy checklists. FREE CD-ROM includes source code in C, the Microchip C30 compiler, and MPLAB SIM. 400 pages paperback. By Garry Cratt – Latest (7th) Edition 2008 $49.00 Written in Australia, for Australian conditions by one of Australia's foremost satellite TV experts. If there is anything you wanted to know about setting up a satellite TV system, (including what you can't do!) it's sure to be covered in this 176-page paperback book. See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* PRACTICAL GUIDE TO SATELLITE TV See Review March 2010 ELECTRIC MOTORS AND DRIVES By Austin Hughes & Bill Drury - 4th edition 2013 $59.00* This is a very easy to read book with very little mathematics or formulas. It covers the basics of all the main motor types, DC permanent magnet and wound field, AC induction and steppers and gives a very good description of how speed control circuits work with these motors. Soft covers, 444 pages. NEWNES GUIDE TO TV & VIDEO TECHNOLOGY By KF Ibrahim 4th Edition (Published 2007) $49.00 It's back! Provides a full and comprehensive coverage of video and television technology including HDTV and DVD. Starts with fundamentals so is ideal for students but covers in-depth technologies such as Blu-ray, DLP, Digital TV, etc so is also perfect for engineers. 600+ pages in paperback. RF CIRCUIT DESIGN by Chris Bowick, Second Edition, 2008. $63.00* The classic RF circuit design book. RF circuit design is now more important that ever in the wireless world. In most of the wireless devices that we use there is an RF component – this book tells how to design and integrate in a very practical fashion. 244 pages in paperback. PRACTICAL RF HANDBOOK AC MACHINES By Jim Lowe Published 2006 $66.00* Applicable to Australian trades-level courses including NE10 AC Machines, NE12 Synchronous Machines and the AC part of NE30 Electric Motor Control and Protection. Covering polyphase induction motors, singlephase motors, synchronous machines and polyphase motor starting. 160 pages in paperback. PRACTICAL VARIABLE SPEED DRIVES & POWER ELECTRONICS Se e by Malcolm Barnes. 1st Ed, Feb 2003. $73.00* Review An essential reference for engineers and anyone who wishes to design or use variable speed drives for induction motors. 286 pages in soft cover. Feb 2003 BUILD YOUR OWN ELECTRIC MOTORCYCLE by Carl Vogel. Published 2009. $40.00* by Ian Hickman. 4th edition 2007 $61.00* Alternative fuel expert Carl Vogel gives you a hands-on guide with A guide to RF design for engineers, technicians, students and enthusiasts. the latest technical information and easy-to-follow instructions Covers key topics in RF: analog design principles, transmission lines, for building a two-wheeled electric vehicle – from a streamlined couplers, transformers, amplifiers, oscillators, modulation, transmitters and scooter to a full-sized motorcycle. 384 pages in soft cover. receivers, propagation and antennas. 279 pages in paperback. *NOTE: ALL PRICES ARE PLUS P&P – AUSTRALIA ONLY: $10.00 per order; NZ – $AU12.00 PER BOOK; REST OF WORLD $AU18.00 PER BOOK To Place Your Order: INTERNET (24/7) PAYPAL (24/7) eMAIL (24/7) www.siliconchip. com.au/Shop/Books Use your PayPal account silicon<at>siliconchip.com.au silicon<at>siliconchip.com.au with order & credit card details FAX (24/7) MAIL (24/7) Your order and card details to Your order to PO Box 139 Collaroy NSW 2097 (02) 9939 2648 with all details PHONE – (9-5, Mon-Fri) Call (02) 9939 3295 with with order & credit card details You can also order and pay for books by cheque/money order (Mail Only). Make cheques payable to Silicon Chip Publications. ALL TITLES SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST ALL S ILICON C HIP SUBSCRIBERS – PRINT, OR BOTH – AUTOMATICALLY QUALIFY FOR A REFERENCE $ave 10%ONLINE DISCOUNT ON ALL BOOK OR PARTSHOP PURCHASES. CHIP BOOKSHOP 10% (Does not apply to subscriptions) SILICON For the latest titles and information, please refer to our website books page: www.siliconchip.com.au/Shop/Books PIC MICROCONTROLLERS: know it all SELF ON AUDIO Multiple authors $85.00 The best of subjects Newnes authors have written over the past few years, combined in a one-stop maxi reference. Covers introduction to PICs and their programming in Assembly, PICBASIC, MBASIC & C. 900+ pages. PROGRAMMING and CUSTOMIZING THE PICAXE By David Lincoln (2nd Ed, 2011) $65.00* A great aid when wrestling with applications for the PICAXE See series of microcontrollers, at beginner, intermediate and Review April advanced levels. Every electronics class, school and library should have a copy, along with anyone who works with PICAXEs. 300 pages in paperback. 2011 PIC IN PRACTICE by D W Smith. 2nd Edition - published 2006 $60.00* Based on popular short courses on the PIC, for professionals, students and teachers. Can be used at a variety of levels. An ideal introduction to the world of microcontrollers. 255 pages in paperback. PIC MICROCONTROLLER – your personal introductory course By John Morton 3rd edition 2005. $60.00* A unique and practical guide to getting up and running with the PIC. It assumes no knowledge of microcontrollers – ideal introduction for students, teachers, technicians and electronics enthusiasts. Revised 3rd edition focuses entirely on re-programmable flash PICs such as 16F54, 16F84 12F508 and 12F675. 226 pages in paperback. by Douglas Self 2nd Edition 2006 $69.00* A collection of 35 classic magazine articles offering a dependable methodology for designing audio power amplifiers to improve performance at every point without significantly increasing cost. Includes compressors/limiters, hybrid bipolar/FET amps, electronic switching and more. 467 pages in paperback. SMALL SIGNAL AUDIO DESIGN By Douglas Self – First Edition 2010 $95.00* The latest from the Guru of audio. Explains audio concepts in easy-to-understand language with plenty of examples and reasoning. Inspiration for audio designers, superb background for audio enthusiasts and especially where it comes to component peculiarities and limitations. Expensive? Yes. Value for money? YES! Highly recommended. 558 pages in paperback. AUDIO POWER AMPLIFIER DESIGN HANDBOOK by Douglas Self – 5th Edition 2009 $85.00* "The Bible" on audio power amplifiers. Many revisions and updates to the previous edition and now has an extra three chapters covering Class XD, Power Amp Input Systems and Input Processing and Auxiliarly Subsystems. Not cheap and not a book for the beginner but if you want the best reference on Audio Power Amps, you want this one! 463 pages in paperback. DVD PLAYERS AND DRIVES by K.F. Ibrahim. Published 2003. $71.00* OP AMPS FOR EVERYONE By Bruce Carter – 4th Edition 2013 $83.00* This is the bible for anyone designing op amp circuits and you don't have to be an engineer to get the most out of it. It is written in simple language but gives lots of in-depth info, bridging the gap between the theoretical and the practical. 281 pages, A guide to DVD technology and applications, with particular focus on design issues and pitfalls, maintenance and repair. Ideal for engineers, technicians, students of consumer electronics and sales and installation staff. 319 pages in paperback. by Sanjaya Maniktala, Published April 2012. $83.00 Thoroughly revised! The most comprehensive study available of theoretical and practical aspects of controlling and measuring EMI in switching power supplies. Subtitled Exploring the PIC32, a Microchip insider tells all on this powerful PIC! Focuses on examples and exercises that show how to solve common, real-world design problems quickly. Includes handy checklists. FREE CD-ROM includes source code in C, the Microchip C30 compiler, and MPLAB SIM. 400 pages paperback. By Garry Cratt – Latest (7th) Edition 2008 $49.00 Written in Australia, for Australian conditions by one of Australia's foremost satellite TV experts. If there is anything you wanted to know about setting up a satellite TV system, (including what you can't do!) it's sure to be covered in this 176-page paperback book. See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* PRACTICAL GUIDE TO SATELLITE TV See Review March 2010 ELECTRIC MOTORS AND DRIVES By Austin Hughes & Bill Drury - 4th edition 2013 $59.00* This is a very easy to read book with very little mathematics or formulas. It covers the basics of all the main motor types, DC permanent magnet and wound field, AC induction and steppers and gives a very good description of how speed control circuits work with these motors. Soft covers, 444 pages. NEWNES GUIDE TO TV & VIDEO TECHNOLOGY By KF Ibrahim 4th Edition (Published 2007) $49.00 It's back! Provides a full and comprehensive coverage of video and television technology including HDTV and DVD. Starts with fundamentals so is ideal for students but covers in-depth technologies such as Blu-ray, DLP, Digital TV, etc so is also perfect for engineers. 600+ pages in paperback. RF CIRCUIT DESIGN by Chris Bowick, Second Edition, 2008. $63.00* The classic RF circuit design book. RF circuit design is now more important that ever in the wireless world. In most of the wireless devices that we use there is an RF component – this book tells how to design and integrate in a very practical fashion. 244 pages in paperback. PRACTICAL RF HANDBOOK AC MACHINES By Jim Lowe Published 2006 $66.00* Applicable to Australian trades-level courses including NE10 AC Machines, NE12 Synchronous Machines and the AC part of NE30 Electric Motor Control and Protection. Covering polyphase induction motors, singlephase motors, synchronous machines and polyphase motor starting. 160 pages in paperback. PRACTICAL VARIABLE SPEED DRIVES & POWER ELECTRONICS Se e by Malcolm Barnes. 1st Ed, Feb 2003. $73.00* Review An essential reference for engineers and anyone who wishes to design or use variable speed drives for induction motors. 286 pages in soft cover. Feb 2003 BUILD YOUR OWN ELECTRIC MOTORCYCLE by Carl Vogel. Published 2009. $40.00* by Ian Hickman. 4th edition 2007 $61.00* Alternative fuel expert Carl Vogel gives you a hands-on guide with A guide to RF design for engineers, technicians, students and enthusiasts. the latest technical information and easy-to-follow instructions Covers key topics in RF: analog design principles, transmission lines, for building a two-wheeled electric vehicle – from a streamlined couplers, transformers, amplifiers, oscillators, modulation, transmitters and scooter to a full-sized motorcycle. 384 pages in soft cover. receivers, propagation and antennas. 279 pages in paperback. *NOTE: ALL PRICES ARE PLUS P&P – AUSTRALIA ONLY: $10.00 per order; NZ – $AU12.00 PER BOOK; REST OF WORLD $AU18.00 PER BOOK To Place Your Order: INTERNET (24/7) PAYPAL (24/7) eMAIL (24/7) www.siliconchip. com.au/Shop/Books Use your PayPal account silicon<at>siliconchip.com.au silicon<at>siliconchip.com.au with order & credit card details FAX (24/7) MAIL (24/7) Your order and card details to Your order to PO Box 139 Collaroy NSW 2097 (02) 9939 2648 with all details PHONE – (9-5, Mon-Fri) Call (02) 9939 3295 with with order & credit card details You can also order and pay for books by cheque/money order (Mail Only). 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