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siliconchip.com.au September 2004  1 SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings.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.17, No.9; September 2004 FEATURES 8 Voice Over IP (VoIP) For Beginners www.siliconchip.com.au Cooking Up 2.4GHz WiFi Antennas – Page 14. A computer, an Internet connection and a headset or “netphone” are all you need to make long distance phone calls for free – by Ross Tester 14 WiFry: Cooking Up 2.4GHz Antennas Turn a $10 cooking scoop into a high-performance WiFi antenna for extended signal range – by Stan Swan PROJECTS TO BUILD 30 Bed Wetting Alert Sounder For Toddlers Bed Wetting Alert For Toddlers – Page 30. Keep the tide out with this effective bed wetting alarm. You just add some circuitry to Jaycar’s “Secret Farter” and make a sensor – by John Clarke 37 You’ve Had Your Fun – Now Make A Doorbell OK, you’ve shocked Aunt Martha and embarrassed your granny with your fiendish Secret Farter. Now turn it into a useful doorbell – by John Clarke 40 PICAXE The Red-Nosed Reindeer It’s based on the new PICAXE-08M chip, flashes its nose and eyes and plays popular Christmas tunes and mobile phone ring tones! – by Clive Seager 64 Build A Programmable Robot Here’s a great school project! This robot features full manoeuvrability, speed control, bump-and-respond logic and programmable sound and light sensing. Turn it loose and watch it head for the light – by Thomas Scarborough 76 Oh No! Not Another CFL Inverter Yep, another one but this one’s really simple. It’s powered from 12V and is just the shot for running multiple compact fluorescent lights (CFLs) or even a small colour TV set – by Graeme Matthewson SPECIAL COLUMNS PICAXE The Red-Nosed Reindeer – Page 40. 24 Circuit Notebook (1) USB-Powered PIC Programmer; (2) Economical Desk Lamp For Camping; (3) Quartz Clock Flasher Protects Equipment; (4) Two Switches Share One Pin; (5) Multi-Level Lock System; (6) PICAXE-Controlled Battery Charger 56 Serviceman’s Log You have to be versatile in this game – by the TV Serviceman 80 Vintage Radio This Little Nipper was a dog – by Rodney Champness DEPARTMENTS 2 4 53 55 71 Publisher’s Letter Mailbag Product Showcase Silicon Chip Weblink Order Form siliconchip.com.au 86 89 94 96 Ask Silicon Chip Notes & Errata Market Centre Ad Index Build A Programmable Robot – Page 64. September 2004  1 PUBLISHER’S LETTER www.siliconchip.com.au Publisher & Editor-in-Chief Leo Simpson, B.Bus., FAICD Production Manager Greg Swain, B.Sc.(Hons.) Technical Staff John Clarke, B.E.(Elec.) Peter Smith Ross Tester Jim Rowe, B.A., B.Sc, VK2ZLO Reader Services Ann Jenkinson Advertising Enquiries Phil Benedictus Laurence Smith Benedictus Smith Pty Ltd Phone (02) 9211 9792F Fax: (020 9211 0068 info<at>benedictus-smith.com Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Julian Edgar, Dip.T.(Sec.), B.Ed Mike Sheriff, B.Sc, VK2YFK 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: $76.00 per year in Australia. For overseas rates, see the subscription page in this issue. Editorial & advertising offices: 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 High voltage warnings err on the side of caution This month one of our correspondents in the Mailbag pages, Otto Hoolhorst, takes us to task for being unduly cautious in including a warning about monitoring mains voltages. The particular warning was on page 38 of the July 2004 issue and pertained to 240VAC voltage and current waveforms in the Energy Meter project. Mr Hoolhorst makes the point that many people would have the equipment and the know-how to monitor these waveforms and for these people at least, such measurements would be routine. That is entirely realistic and yes, the warning really does only apply to electronics novices. We do tend to err on the side of caution when we consider the possibility of novices attempting to make high voltage measurements. If a novice did have a scope and a high voltage probe, it would certainly be possible to make the voltage measurements, with the scope earth return connected to earth of the measured circuit. It should not be connected to Neutral, unless it has already been confirmed that Neutral is at earth potential. Why? Because it is possible that the power point wiring or the power cord itself could have Active and Neutral transposed. That rather muddies the water doesn’t it? So while Mr Hoolhorst correctly notes that all voltages in the Energy Meter circuit are referenced to Neutral, it is not necessarily safe to put a scope earth return on the Neutral line, because Active & Neutral might be transposed. That possibility would be taken care of if you are using differential probe connections but again that implies fairly high knowledge levels. I agree that warning notices possibly do deter hobbyists from learning how such measurements can be made but if we were to include all the information on such methods in each project article where high voltages are involved, it would be a major undertaking. And then of course, we would risk boring all those readers who actually know what is involved. So we have taken the safe way, hoping to discourage novices from getting into trouble. Even experienced people can get into trouble making measurements on today’s cramped PC boards and a moment’s inattention can lead to accidents. I have to admit to a little accident of my own this month when checking waveforms in the CFL Driver project featured on page 76 of this issue. I was checking the buffer output switching waveform at pin 14 of the switchmode controller IC when the probe slipped ever so slightly, shorting pin 15 (+12V) to pin 14. There was a slight crack and all the smoke suddenly escaped from one of the Mosfets as it blew apart. It wasn’t a good moment for my self esteem. Maybe I should have left the measurements to someone else on the staff . . . Incidentally, we’ve also got a warning on that project, due to its high voltage DC output of 350V. Such a warning needs to be included, otherwise it would be too easy to be lulled into the idea that, because it’s such a small and innocuous PC board running from 12V, its output can’t be lethal. Well think again: in the wrong circumstances, 350V can be lethal! So while we have presented it as a PC board, it needs to be safely installed in a case so that accidental contact with high voltage cannot happen. Are we being too cautious? We don’t think so. What do you think? Leo Simpson * Recommended and maximum price only. 2  Silicon Chip siliconchip.com.au Spr ng USB Net Phone This USB net phone allows users to make free calls with programs such as Skype (www.skype.com) when connected to the internet. Cat 10129-7 $89 into these great ideas from MicroGram NEW! Multi-homed ADSL Router Enhance reliability & double your ADSL capacity by using two different ISP’s. Cat 10145-7 $399 USB Digital TV Tuner Watch and capture (mpeg-2) digital TV broadcasts on your PC or Notebook. Cat 3547-7 $319 NEW! Front Access DV/AV Capture Tired of plugging your video cables into the back of your PC? Bluetooth GPS Turn a Bluetooth capable PDA, Laptop, or Smartphone into a GPS. Cat 11433-7 $469 Cordless Barcode Scanner A great laser scanner for use around a shop floor or warehouse. Range of 30m (open air) and has a “good read” feedback when a barcode is successfully scanned. Cat 1008154-7 $1199 This capture card is designed to capture from DV/D8 camcorders or analogue video devices, such as Hi8/V8/VCR/TV/DVD. Comes with Ulead VideoStudio 7 and Ulead Movie Factory 2 software. The handy front access bay fits in a 5 ¼” drive bay, and has RCA, Firewire, S-Video, Mic and a USB 2.0 port. Cat 23027-7 $399 Gigabit PCI Adapter NEW! POS Receipt Printer Add a high speed gigabit port to your PC with this inexpensive 1000/100/10Mbps NIC. Cat 11359-7 $41 A 42 column dot-matrix receipt printer. Great for entry level POS applications. Cat 5849-7 $499 8 Port SATA RAID USB Extender Allows eight SATA drives to be connected in a RAID array. Compatible with 32 and 64 bit PCI slots. Cat 2905-7 $649 Use a USB device up to 50m away from a PC over inexpensive UTP cable (not included). Cat 11666-7 $105 Digital I/O Card USB Auto-Reset Windows XP Terminal Provides 48 digital I/O lines on a PCI PnP interface card. Has three 16bit counters with a maximum count rate of 10MHz. Cat 17053-7 $249 If a computer stops responding this USB device will apply a hardware reset. Great for remote computers with no operators. Cat 17084-7 $169 The Windows Based Terminal operates under Windows XPe, and is suitable for both NT/2000 server and Unix host. Cat 1158-7 $1299 RFID Access Control USB PCMCIA Reader This USB 6 in 1 memory card reader is capable of reading full size ATA flash cards. Cat 6785-7 $99 Great for any RFID security application, with an LCD display and serial output for a PC. Cat 1008143-7 $549 DVI KVM Switch A two way KVM switch for use with a DVI monitor and PS/2 mouse and keyboard. Cat 11663-7 $169 Video to VGA Magnetic Card Reader Display any video signal on a VGA monitor. Has S-Video and RCA inputs. Cat 3479-7 $259 Reads track 2 on any magnetic card and inputs it into a PC via a keyboard wedge. Cat 8681-7 $219 Thin Client Terminals! We’ve got them for Serial, Ethernet, Windows Based and Linux applications 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 SHORE AD/MGRM0904 Dealer inquiries welcome MAILBAG Automating PC Power-Up In the June 2004 edition of SILICON CHIP, page 77, you had a small item on how to modify your ATX type PC motherboard to start up on applying the power, rather than by the front case ON/OFF button. It’s even easier than that for almost all ATX motherboards. Every ATX motherboard that I’ve seen/used has an option in the BIOS to have the PC start when power is applied. In my rather outdated ASUS A7V motherboard BIOS it appears under Power ->Power Up Control->AC PWR Loss Restart from which I have a choice of “Disabled” [Default], “Enabled” or “Previous State”. In my more current EPOX 8RDA+, it appears in the BIOS as Integrated Peripherals->PWRON After PWR-Fail, with the choice of “Disabled” [Default], “Enabled” or “Previous Status”. You only need to set it to “Enabled”, save the BIOS settings and from then on, every time power is applied, the PC will start booting. It only takes a little reasoning to realise that this is probably available in all ATX BIOS’; eg, wouldn’t you want a PC that’s doing critical data logging/process monitoring to be up and continuing its operations as soon as power is restored after failure? Dave Clarke, via email. Comment: we thought of this at the time. What you’re saying makes sense but the motherboards we checked did not have this option. More praise for vintage Tektronix scopes Over recent months there have been a number of references to vintage Tektronix CROs in these columns. My familiarity with the breed goes back the early 1970s and in particular, the model 564B with storage facilities. The term “built like a battleship” certainly applies to that generation. The build quality was something that one rarely sees today with the plethora of ASICs, multi-layer printed circuits and plastic everything. There 4  Silicon Chip wasn’t an IC to be seen. Instead, it had a mixture of discrete transistors (and the then quite new tunnel diode) and glass valves, including one of the last hurrahs of the valve era, the Nuvistor. However, with all those discrete components, over their long lives they did need “fixing” from time to time. I have a lengthy list of repairs carried out to my model over its lifetime (it is still here and working as well as ever) and wondered if some out there are familiar with the fact that the vertical and horizontal “plug-ins” can be safely interchanged’ ie, fit the vertical amplifier in the right bay and vice-versa. This is a great help when diagnosing faults dynamically, as it allows access to the component side of each chassis. Of course, the trace becomes vertical instead of horizontal but otherwise everything works as normal. The only exception that I am aware of is that the trace brightening signal for the delayed scan is not picked up in the left bay. Brian Critchley, via email. PC board design hint for creating Postscript file Your PC Board Design tutorial has been an invaluable resource to me. However, I would like to point out that in Pt.3, there is a small omission that may cause readers some difficulty. When creating a postscript file with Traxplot, the Postscript Setup default value for Quality is “Draft”. You must change this to “Final Artwork” or your resulting file will appear as line art instead of solid tracks, pads and components. Thanks again for your fine series of articles. Mako Natsume, via email. Impressive design in ESR meter I am writing to congratulate you on the magazine. I have read every Oz electronics magazine since 1940, with a few gaps during WW2. SILICON CHIP is as good as any of them. Thank the developer of the ESR meter. I have just finished building one and am very impressed with its design and abilities. Tony O’Brien, VK2BOA, via email. Unnecessary warnings discourage initiative SILICON CHIP magazine seems to come up with one excellent project after another. I am particularly grateful for the “Energy Meter” project in the July and August 2004 issues and will be building a number of these. However, I object to the caution on page 38 of the July 2004 issue, in relation to viewing waveforms of the Energy Meter circuit. Surely SILICON CHIP realises that there are a significant proportion of its readers who could safely connect their scopes to this circuit. Why then, have a warning that applies only to completely inexperienced hobbyists. Such a warning actually deters those hobbyists from learning how such oscilloscope viewing could be safely accomplished? Have lawyers and insurance companies really screwed up our society to that extent? Every day, all over Australia, many electrical and electronics engineers, technicians and hobbyists are connecting monitoring instruments to circuits at mains potential. I am convinced that anyone who has a suitable scope probe and has sufficient knowledge to use it could safely monitor the waveforms in the Energy Meter circuit. The most common suitable probe would be a passive 100x probe with a voltage rating of 1kV or more. I have two of these and use them regularly. One of these is an ETM 2101, a low-cost 100x probe rated at 1.2kV which I have siliconchip.com.au owned for 15 years. The other probe is a Tektronix P5100, a 100x probe rated at 2.5kV (purchased as new on eBay for US$160, with freight from the US an extra US$9, making a total of approximately $240 Australian). Other suitable but less common probes are high voltage differential probes, such as the superb (but pricey) Tektronix P5205. The advantage of a differential probe is that “floating” measurements can also be made using only one channel of a scope. However, with two suitable 100x passive probes and a 2-channel scope in differential mode, such mains level floating measurements can be made much more cheaply. The Energy Meter circuitry is referenced to Neutral and I am convinced that a suitable 100x passive scope probe could be used safely by a relative novice to view at least some of its mains voltage waveforms using only one channel of an oscilloscope. One simply uses the “witches hat” probe accessory on the probe tip and hooks this to the desired test point BEFORE applying power to the circuit (but first remove the accessory grounding cable if it is connected to the probe tip). Of course, the power would need to be turned off again BEFORE disconnecting the probe. I find it extremely difficult to believe that even a novice would get into trouble if they followed this procedure. I am convinced that relatively inexperienced electronics hobbyists are entitled to “learn how to do it properly”, even if they have no intention of pursuing formal qualifications in electronics. If we continue to succumb to the “electricity is voodoo” garbage promoted by vested interests such as the electricians’ lobby and their allies in the insurance sectors, we will surely kill off knowledge and initiative. Otto S. Hoolhorst, Brisbane, Qld. Comment: we still think the warning is a good idea. The Publisher’s Letter on page 2 has further details. Big cooler envy I have recently spent a great deal of time trying to find a way of making my computer system quiet. I noticed your July 2004 issue had an article on how siliconchip.com.au to silence a screaming computer. I was impressed by the Zalman “Reserator” system which I promptly purchased from my local computer store. I was almost overwhelmed with the size of my Reserator (600mm) but on re-reading your article (600m) this gave me a feeling of inadequacy and I was tempted to ask my supplier for the same model you have acquired. In the meantime, I humour myself by putting a “hazmat” sticker on it and telling friends I have a nuclearpowered computer. Garry Surplice, Campbelltown, NSW. Comment: sorry you feel inadequate. It is just that computers and coolers for SILICON CHIP magazine need to be much bigger so we got a 600m unit. It is quite imposing and does need aircraft warning lights and very big foundations but we have found it very effective at cooling. So effective in fact that we have experienced climate change in the whole Northern Beaches area. We are thinking of turning it into a local tourist attraction, with rides, bungee jumping, etc. 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 Short life from CFLs I couldn’t agree more with Leo Simpson’s write-up in the August 2004 issue on compact fluorescent lights. We have seven of these globes in our house and so far we have replaced four of them within six months of installing them as brand new units. This is not good enough. Or is it is a conspiracy by these companies so they make bigger and bigger profits at our expense? If so, we should all go back to the incandescent globe until they get it right. Russell & Kerin Sharp, Morphett Vale, SA. 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. Long life from CFLs I read with absolute amazement your editorial on compact fluorescents (August 2004 issue). In my experience, their life is “as advertised”. I live in a townhouse and I purchase globes for outside lighting on behalf of the Body Corporate. More than 10 years ago, we installed four CFLs under the carports (ie, sheltered from the weather) and these are on from dusk until dawn every day. 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 September 2004  5 Mailbag: continued Over the year, this would probably average about 10 hours per day. To keep track of the life, I mark the installation date on the base of the lamp. At the moment, we have one which has been in use since July 2002 and it is still working fine. This is normal; I don’t expect anything less than two years from them, which works out at more than 7000 hours. The main brands that we use are Philips and GE. What is happening in Sydney? Maybe your electricity supply is very bad. Perhaps you should monitor it for a while to see just what voltage fluctuations, spikes, etc are occurring. David Bramwell, Melbourne, Vic. PC boards from negative-acting resist Further to the letter by Geoff Thomas in the June 2004 issue, I offer the following suggestions for producing boards of the same quality as Geoff alluded to but even cheaper, using standard LaserJet transparency film. The first is to use negative-acting PC board material in place of positive. In this case, tracks correspond with clear artwork areas, so the sieve-like quality of artwork derived from standard transparency film does not compromise the integrity of tracks. The only possible (and obviously undesirable) effect is to leave unwanted copper in gap areas, leading to bridging. This is averted by lightly brushing the PC board with a 2-inch paintbrush to physically assist resist removal during development under subdued yellow light. This does not remove fine tracks, once optimum conditions of exposure, development and developer temperature have been established. Another advantage with negativeacting resist is that artwork may be drawn with very small gaps between tracks, because the width of gaps increases during exposure and development. The reverse is true of positiveacting material. That is, bridging occurs if gaps are drawn too small. I have never had a problem drawing 0.00325” gaps under vacuum exposure. The only real downside to the 6  Silicon Chip negative-acting material I use is that it is covered by a thin transparent Mylar protective film, causing handling and cutting difficulties. A guillotine is best for cutting it to size. On the upside, it can be developed safely, quickly and at negligible cost using dilute sodium carbonate solution. Also, the clear Mylar forms a barrier between artwork and resist, negating the possibility of sticking under high vacuum exposure. As part sheets of transparency film may be recycled through the LaserJet, the materials cost per small project artwork and development is around $0.40. What is more, once experiment has yielded optimum exposure and development conditions, it works first time every time, with the potential to produce project artwork of such fineness that the home constructor could not reliably solder components to the resulting PC board. Ross Metcalf, via email. Hifi power cords and other Kozmic bunk I agree with David Collins (Mailbag, July 2004) that the scientific paradigm requires testing a hypothesis. However, the hypothesis in this case is that a different power cord will make an amplifier sound different, not Leo Simpson’s quite unexceptional assertion that it won’t. David is only a little bit pregnant in demanding rigour. There are some other philosophical rules of reasoning that must be applied also. The first is that it is impossible to prove a negative. One test can show it does have an effect but only an infinite number of tests can show it doesn’t. And while the tests proceed, the carpetbaggers continue to fleece the sheep. I’m sure that Golden Ears will assert that they can hear a difference. But this is totally unscientific anecdote, only a possible starting point for an investigation using doubleblind crossover techniques and not a triumphant QED. The second, and in this case more to the point, is that extraordinary claims require extraordinary proof. Many of the claims made for hifi systems and accessories are so extraordinary as to be absurd, and like assertions of a flat Earth and perpetual motion, can be safely rejected out of hand. There is also the paradox of the frequent demand by “Hiper-Finatics” that critics rigorously follow scientific method, but who make wild and untestable claims based on nothing better than subjectivism operating somewhere outside long and well established theory. David should save his concerns for the much more complex amplifier at the end of the lead which also operates “only theoretically”. Without “only theory” he wouldn’t have an amplifier to worry about powering in the first place. The snobbish egocentric entrenched ignorance and self-deception endemic in the world of so-called hifi (“my ears are better than your instruments”) would only be sad were it not for the very considerable sums of money that change hands as a result, leading to outright fraud. Roly Roper, Ivanhoe, Vic. Valve electronics not practical in the long term I refer to the letter entitled “Valve Electronics Never Reached Its Peak” in the June 2004 issue. I cannot believe that anyone would think that vacuum tube technology could ever be a practical long-term system of electronics. Valves are cumbersome, power hungry, fragile and unreliable. What possesses your correspondent to think otherwise? Don’t get me wrong; I love vacuum tubes. My first one-valve radio was nothing short of miraculous to me. I also remember reading about the invention of the transistor. I am surprised that the transistor was not stumbled upon by Graham Bell. I’ll bet that if he were more into physics than phonetics, this would have happened. I think that vacuum tubes were a natural stepping stone to solid-state electronics. From my reading and observations, it appears that great ideas come as a result of the thinking of many. Sources of invention are the province of the prepared mind. How wonderful it would be to sit in the siliconchip.com.au shed and invent wonderful things by some serendipitous process. Alas, the mental capacity, economic capability and stamina required to make major discoveries and the realisation of such discoveries now seems to be beyond the individual. With this in mind I think that valves (vacuum tubes) did indeed reach their full potential. Solid-state technology is a further step along the continuum of scientific discovery. Lionel Doolan, Newcastle, NSW. Valves are dinosaurs I certainly don’t agree with Grahame MacPherson’s letter on valve technology versus the transistor. Valves in my opinion are dinosaurs, wasteful of energy, not nearly as robust, and expensive. The warmth of a valve amplifier is a myth and rates alongside the jumbo speaker cable hocus pocus. I built my “Hikers One” valve radio as a boy back in 1951 and went on to build a superhet five, so I guess I cut my teeth on valve technology and enjoyed the experience. But the advent of the transistor and PC boards for the electronic enthusiast was a wonderful breakthrough as well as sheer joy. Brian Gardner, Kettering, Tas. Video standards article is very useful I must commend Jim Rowe for his excellent August 2004 article on “Video Formats: Why Bother?” I’m sure many readers would have gained from the concise explanations and clear photographs. In the UK two years ago, my TV, VCR, hifi, etc, all interconnected seamlessly with the ubiquitous European standard 21-pin SCART connector, which I believe has separate RGB on pins 15, 11 & 7 respectively, with ground at pin 13; a very tidy and compatible solution! Would it be sensible to embrace this standard in Australia? There are two objections perhaps: the standard is outdated by home entertainment system requirements; and the connectors are too large for cameras, laptops and digital video recorders. The latter can be solved with an S-video to SCART adapter. I used one to connect my siliconchip.com.au Geforce 3 Ti300 video card to the TV. Finally, a big thanks to SILICON CHIP. It is the finest electronics magazine I’ve seen world-wide. The print quality is second to none, the articles excellent and the advertising highly relevant. Robert Gott, Toowoomba, Qld. Quiet PCs don’t need fans I read your article on silencing PCs, in the July 2004 issue, with interest. Noisy PCs are not a new phenomenon – I recall using one of the early IBM PCs and it reminded me of a jet aeroplane taking off. In your article, you focused exclusively on how to build a top-of-the-line system that did not require you to wear earmuffs. There is an alternative approach – start with a system that doesn’t need forced-air cooling. VIA make a range of CPUs that don’t need active cooling. Whilst they are only in the 500-800MHz region, this is plenty fast enough for normal multimedia or office work. The power consumption is low enough that the power supply doesn’t need a fan either, so the only moving part is the disk drive. You can build a whole PC that needs less power than a top-end CPU. For details see www.mini-itx.com. You can also buy them locally at www. traverse.com.au Also, you mention cleaning the heatsink compound off when changing heatsinks. Some heatsink compounds include beryllium oxide – this is highly carcinogenic and you should be careful to avoid contact with it. Peter Jeremy, via email. Comment: we agree that the VIA CPU is a valid approach – except that a lot of today’s software demands higher speed and performance. Making solar power pay I moved from Sydney to Adelaide a little while back. The combination of higher energy prices and lower housing prices led me to look at how I could use some of the cash I had left in my pocket to cut my utilities bills. There were all the obvious things like replacing all the incandescent globes with compact fluorescents and replacing the curtains with ones that would reduce heat loss. I had planned to do solar power too, feeding excess power generated back into the mains and turning the meter backwards, but when I looked at it closely I found that all the groups involved had, while saying that people should do it, gone out of their way to make it as difficult and uneconomic as possible. Enough solar panels to generate 1kW under ideal conditions cost about $8000 and you get $4000 back from the government, leaving only $4000 to pay. But this is only if it’s all designed and approved and installed by people who manage to inflate that to about $11,000. That investment only generates about $275 worth of power a year, even at Adelaide’s prices. It’s a better proposition to take your $11,000, invest it in a term deposit and pay your power bills out of the interest. It’s amazing that anyone does it. How to get the power up? What about a system of stainless steel reflectors to produce an effective 40% increase in output. How to get the price down? There are things you can’t get the price down on, like having a qualified electrician do the mains side of the wiring. But other than the solar panels themselves, the big ticket component is the DC-to-240V 50Hz inverter that connects to the mains. There’s nothing high-tech about it but there is only one product you can buy: Latronics PV Edge, costing about $3500. Its a good product but there has to be a cheaper way of doing it. Is a mains-connectable inverter a project that SILICON CHIP would do? Gordon Drennan, Burton, SA. Comment: back in March 2002 we published an article debunking domestic solar power installations and noting that the “pay-back period” was around 20 years – far too long to be a sensible investment. We also suggested other more effective means by which people could cut their greenhouse emissions, such as buying a new car, fridge, dishwasher, etc. We got a lot of flak for that article but as you have found, it is still correct. Nor do we think that improved focusing onto the panels or cheaper regulation circuits would change the basic economics by much. SC September 2004  7 How to call lo FREE or Hands up if you’ve heard about VoIP technology. Keep those hands raised if you knew that with a personal computer and internet connection, you could make very cheap – or even free – long-distance and international calls. Mmm. Not quite so many hands up now? I n the “New Products” section last month, we featured a USB “NetPhone” from MicroGram Computers, which allows any computer with an internet connection to effectively become its own international telephone exchange. Well, slight exaggeration perhaps: nevertheless, it does allow you to make (and receive, of course) “phone” calls to and from anywhere. We’ll look at how this works a little later. But this is an example of a technology that very few people, except those “in the know” are aware of. Yet! It’s called VoIP – Voice over IP. What is VoIP? It is no more, nor no less, than its name suggests. Voice (predominantly telephone-type by Ross Tester 8  Silicon Chip siliconchip.com.au ong distance P2P VoIP For Beginners calls) sent over the internet (IP stands at your computer and sent via your How about WiFi? There are some altruistic WiFi sites for Internet Protocol). internet connection to anyone on the In a normal telephone call, made via planet who has also has an internet around which allow you free internet access (yes, there are a lot more which what is known as the POTS, or plain connection. old telephone system (also known Many references claim that you need charge but many are free – at last count as the PSTN, or public switched tela broadband or high-speed internet about 3700 in Australia with almost 900 of those in Sydney, according to ephone network), your voice is conconnection to make this work. verted (via a microphone) to an analog Trust us, you don’t. A plain old dial- www.sydneywireles.com). Grab a notebook computer with electronic waveform, routed via a vaup is good enough (as long as the speed riety of telephone exchanges to where stays up near 33.6kB/s). The downside WiFi, log in, plug in your headset or you want it to go, then converted back is, of course, that you pay a local call NetPhone and now you do have totally to audio (via an earpiece) at the fee every time you make an internet free international phone calls. We’ve all heard the stories about backpackers receiver end. and students using the ’net Well, at least that’s the “I knew it was over wh en I downloaded to tell colleagues about “broway telephone systems used Skype. When the inve ken” public phones which to work. ntors of KaZaA ar e distributing for free allow free international calls. These days, especially a little program No need any more: they for long distance calls, the that you can us e to talk to anybody can use the ’net itself to make chances are that it works else, and the quality is fantastic, and those international calls withthat way until the telephone it’s free – it’s over. Th out breaking any laws! exchange, whereupon the e world will ch ange now inevitably.” analog signal is digitised Is it legal? and converted into “packMichael Powell, Chai Speaking of breaking laws, ets” of data, routed to where Federal Communicat rman, US it’s often asked if you are doing it has to go as a digital sigions Commission just that by making free calls. nal, then converted back Not at all: VoIP is absolutely to analog at the receiving phone 100% legal. You are not stealexchange and finally, sent to the receiver as an analog signal. call. ADSL/Cable is “always on” so ing anything. You are not misapproRecently-released figures suggest you can make that call effectively for priating anything. You are not even using something in a manner for which that Telstra is currently converting at nothing. least 20% to digital but this is likely to OK, you still have to pay the it wasn’t intended. You are using the dramatically increase soon, if it hasn’t monthly ISP ADSL/Cable connection internet exactly as it was planned – done so already. fee. But you’re going to do that any- sending and receiving packets of data What P2P VoIP does is exactly the way, so we reckon the “free” claim is around the world. It just so happens that the data, in same – except that it is done right perfectly valid. siliconchip.com.au September 2004  9 this case, is a fully encrypted, digitised Similarly with multinationals: with read this! The other reason, of course, version of your voice (or someone VoIP, an office manager in Liverpool, is that VoIP, or at least its implemenelse’s voice that you talking to!). Australia can pick up his phone and tation, wasn’t particularly common All you are doing is effectively bytalk to a colleague in Liverpool, Engknowledge! And we’re changing that, passing the POTS/PSTN (even though land – and the company telephone bill right now! you are using a phone line to get to will not be bothered one bit! If you regularly talk to someone the telephone exchange and thence One research company estimates overseas and your telephone bill is, to the world via the net). As far as the that around 4% of international say, $100 month, P2P VoIP will have telephone exchange is concerned, it’s corporate telephone communication you well in front before the end of the all data. is now via IP but this is expected first month. Now that is some saving! Because you are not going through to rise to 44% within three to four Less frequent callers will make less the exchange as such, you aren’t going years – it’s largely just a matter of savings – but you will make savings through their pesky metering systems companies getting off their leatherbecause calls can be totally free. which normally result in you receiving bound backsides. All I can say is where was VoIP nasty letters each month. VoIP starts getting complicated when number one son spent five years Again we must mention that dial-up with big companies and common swanning around the globe and his connections will cost you at least a names – just recently we heard of a mother told him to call whenever he local call. And if you’re on a timed uscompany with about six John Smiths liked, reverse charges . . .? age plan (ADSL or dial-up) as distinct in Australia, confusing enough, but P2P Networks from a “per MB/GB” or “unlimited” now has about 60 John Smiths around plan, using a NetPhone will eat into the world on its VoIP system! While traditional VoIP systems have your time, just the same as any ’net Until recently, corporate VoIP been very good within an organisation usage does. equipment hasn’t been particularly using its own network, VoIP calls to If you make regular overseas calls, cheap – but certainly cheap enough to “ t h e outside” have not been as sucyou will almost certainly find it pays cessful. For one thing, call to get a broadband net concompletion rates have been for calls belongs nection, which you can too low, due in part to the use “The idea of charging s ve gi e ar ftw so e theoretically get these days of firewalls and also the use of yp Sk to the last century. in y sta ly for less than $20/month. I Network Address Translation ab rd fo af w power to by say theoretically because people ne (which renders over 50% of ily m fa d an ds touch with their frien r technology and at home I had to settle for residential computers unable ei th of e ag nt va ad much-more-expensive cable to communicate with trading ki ta ts.” en stm ve broadband because Telstra tional VoIP software). in ity tiv ec conn claimed “incompatible inThis is changing very quickNiklas Zennström, Skype frastructure” when I applied ly with the emergence of peerfor ADSL! to-peer (P2P) networks. CEO & Co-founder of In a P2P network, the How can Telcos allow operator takes advantage of the fact free calls? warrant its installation, given the huge that thousands of computers (perhaps savings made down the track. hundreds of thousands or more) are Quite simply, they cannot stop it. We’re not particularly concerned logged on to the network at any given They have bent over backwards to try with corporate VoIP in this article. time. to get Australians on the net. Then they There are plenty of organisations These computers share the network tried equally hard (and are still trying) around who are more than able to workload – traffic routing, processing to get Australians onto broadband. help out corporates with anything and bandwidth-intensive tasks that Well, VoIP is one of the un-publithey need. What we are interested in would otherwise be handled by huge cised benefits of an internet connechere is VoIP for the average (ie home/ (read expensive!) central servers. tion. small business/etc) computer user – By spreading the data crunching We’re quite sure Mr Switkowski and eg, you and I! around the networked computers the co would much prefer media such as operator doesn’t have to invest big SILICON CHIP would keep quiet about VoIP for the masses . . . dollars in computer infrastructure. VoIP so they could keep their nice litCost is almost certainly one of It’s a system that has become poputle earner (long distance and overseas the main reasons that VoIP has been lar amongst computer users over the phone calls) going. Now you know relatively slow to take off outside the last few years for so-called “file sharabout VoIP, you don’t need to feed corporate area. It’s only fairly recently ing” networks – eg, KaZaA, Napster, their coffers as much! that equipment low enough in price etc – because it appears they are getHow long’s this been going on? has become available for the aver- ting something for nothing. VoIP itself is nothing new. It’s been age person to start taking advantage That’s not strictly true, of course: around for years. A lot of the large corof VoIP technology and start making they are contributing some of their porates with offices in various states savings in phone calls. own computer power to the network to have been using their own intranets And the software to make it hap- make it happen. But as no actual coin for VoIP calls, saving themselves pen hasn’t been commonly available. of the realm needs to change hands, thousands of dollars in STD charges. That’s all changing, literally as you to most people it’s “free”. 10  Silicon Chip siliconchip.com.au Of course, the actual files shared via P2P could, in many cases, be illegal copies but it’s not so much the content of P2P we are looking at; it’s the way the system works. And while courts in the US ruled against Napster in the most celebrated P2P case, a recent court decision in Canada has gone the other way, ruling P2P networks (and file sharing) as quite legal. This mainly concerns the music and video industries and should not affect services such as P2P VoIP. Calls to “normal” phones So far, all we have considered are P2P VoIP calls between two suitablyequipped computers. But VoIP is capable of much more, including phone calls to “normal” (POTS/PSTN) phones and even mobile phones – again, anywhere in the world. Unlike the PC-to-PC variety, there is a cost to these calls, as it involves using a telephone service provider to connect into the phone system at the far end. But invariably, the cost of such calls is a fraction of the normal longdistance or international call cost – as much as 90% off! VoIP achieves this by using the ’net for the majority of the call distance, and then connecting into the phone system at the far end. So it’s almost as if you are making a local call. Calls are usually costed by the minute. But one “carrier” which we’ll look at shortly has rates of about three cents per minute to a variety of major countries, such as the UK, USA, Canada, Ireland, NZ, China, Singapore, much of Europe and Asia and many more (23 in all), including Australia (rate current as at 1st August 2004). The downside, admittedly minor, is that most calls are charged by the minute, so a 5-second call to a wrong number, fax, answering machine, etc will cost you the full one minute rate. Aw, shucks – a whole 3c wasted! Calls to mobile phones Even more importantly when friends and colleagues are travelling around the world, calls to mobile phones in many of the overseas countries are at the same 3c/minute rate. Regrettably, Australia isn’t one of those countries – it’s about 30c per minute. Still, that’s about 25% less than the typical fixed-to-mobile rate of most service providers in Australia siliconchip.com.au – and there doesn’t appear to be any “flagfall” charge. So it would appear that you can call a local mobile phone from your netphone and save a significant amount of money. Call quality There has been criticism about the quality of VoIP phone calls – tinny or unnatural sound being one of them. My experience, with recent equipment, is exactly the opposite. My NetPhone calls are not just better quality, they’re significantly better quality than the same call with a POTS/PSTN phone. In fact, much better voice quality is one of the selling points of the netphone I am using, the K1000 which came from Microgram Computers. I have read of problems calling international mobile phones using dial-up internet – dropouts, truncated speech, etc – but this could have been a slow dial-up connection problem. At the time of writing, agreements with service providers had just been signed, coinciding with the launch of the netphone-to-POTS/PSTN/mobile service. Latency One problem you often read about with netphones is latency – the delay in your voice reaching the other end and vice versa. Latency can range from an echo effect to a real long delay. The delay depends largely on the distance your call has to travel to reach you. You don’t know whether it’s being routed between many, many countries or maybe just a few. Personally, I haven’t found latency a problem. That’s not to say it doesn’t exist – I just haven’t found it a problem! There is also some latency on net-tophone calls but again, my experience is that it’s no worse than on international phone-to-phone calls. Sometimes it’s noticeable, sometimes not. In calls I’ve made to Australian phones, it appears the latency is about 0.5 seconds or so. It might take some people a little getting used to but if it annoys you too much, go back to wasting money on your old-style international and long-distance calls. Dare I say it: it’s your call! Latency is reported to be worse when calling mobiles, particularly those on the other side of the world but so far I haven’t found anyone to call to test it out! (Hey, does someone on a mobile “over there” wanna Skype me?) VoIP Telephones Not yet at all common in Australia but starting to emerge overseas are dedicated VoIP phones – phones which don’t need to connect to a computer and act, for all intents and purposes, like a “normal” phone. Their secret is simple: like any other internet device such as web cameras and the like, they have their own IP address and can be addressed directly from the ’net. You’re sure to see these phones in this part of the world before very long at all. Wot, no netphone? You don’t even need one! While the netphone makes calling very convenient (and everyone is comfortable with using a phone!), all you need is a headset (microphone/earphone) which plugs into your computer sound card. In fact, in some ways it’s even better than a netphone because the earphone and mic give you even better quality. As we’ll see shortly, all the “calling” can be taken care of by mouse clicks, including (if you want) calls to POTS/ PSTN phones. Give it a go! Now let’s look at this again. The software is a free download. You may already have a headset – if you don’t they are available for next-to-nothing. Even buying a Netphone won’t cost you a fortune. If you’re on broadband, it’s not going to cost you any more – dialup will, but not very much. So where’s the catch in making free international or long distance calls? There is just one: getting your partner/kids/etc off the computer when you want to use it, just like getting them off the phone when you want to use it! (Of course you can continue to use the PC while they’re talking but they don’t want you listening in. . .) Apart from that, we cannot think of any reason NOT to jump into P2P VoIP! OVERLEAF: How YOU can do all this, using free “Skype” software! September 2004  11 Want free calls? You wa What is Skype? Starting Skype Simply, Skype is one type of software which drives P2P VoIP. You download Skype, install it and you are ready to go. It’s a 9MB free download, available from www.skype.com We should point out that Skype is but one of many P2P VoIP services available. It just so happens that from our investigations, we believe it’s the best around, if not only because it is free to download and free to use, at least as a P2P system. That is, calls between computers running Skype, where ever they are, will cost you nothing. It also has many features which other P2P VoIP systems cannot claim. Skype was created by Niklas Zennström and Janus Friis, founders of KaZaA (www.kazaa.com) – reputed to be the world’s most popular Internet software. Their experience with KaZaA – itself a peer-to-peer system which allows users anywhere in the world to search for and share files – placed them in good stead when it came to developing Skype. Skype has no advertising, no popups and as far as we can see, no nasties. Zennström and Friis have publicly stated that the P2P section of Skype will remain totally free of charge. Skype has brought on a whole new lexicon. You no longer call friends and colleagues via your computer. You Skype them! And using your PC to Skype is, logically enough, called Skyping. Think those names won’t catch on? Don’t bet the farm on it! Once downloaded and installed, the software will ask you for a Skype Name and password. You can make the user name your own or, if you wish anonymity, you can make up any name you like of at least six characters, no spaces (assuming it hasn’t already been taken, of course). After you have selected a Skype Name and password, you will be asked to fill in a personal profile. Entering information in the personal profile is optional and if you chose to make the profile available to other Skype users, then they will be able to search for you using this information. You can edit this profile at any time; even include a photo of yourself if you wish! Skype doesn’t store your personal profile: it is shared out to other Skype users when you are on the network Skype will not show your “online” or “offline” status to any other user unless you have specifically authorised that person. It’s just one way to protect your privacy but it doesn’t stop that person Skyping you if they have your Skype name. Hardware requirements Skype’s minimum hardware requirements are quite modest: a PC running Windows 2000 or XP with a 400MHz processor, 128MB RAM and 10MB free disk space on your hard drive. A sound card, speakers and microphone are required (see below) and of course an internet connection (33.6Kbps minimum dial-up minimum). In order to take advantage of all of the advanced features of Skype and to experience the best sound quality possible, the following configuration is highly recommended: a 1GHz processor, 256MB RAM and 30MB free space on your hard drive. A full duplex 12  Silicon Chip You’ll be asked to give a Skype Name and a password when you log in. sound card is also better (most sound cards made after 1998 are full duplex) and a headset (earphone/microphone) A broadband internet connection will not only get the most from Skype but will also save you dial-up charges. A PC headset is desirable if you want lowest background noise (or privacy!). These are readily available at electronics and computer retailers and shouldn’t cost you much more than twenty dollars or so. The alternative to a headset or speaker/mic is to use a netphone, as we have shown earlier in this feature. The one we used simply plugs into the USB port and is ready to go immediately. Skype works behind most firewalls and gateways without causing new security risks. Skype calls are encrypted for your security, something the vast majority of public network telephone calls cannot claim. Contact list Your contact list will naturally be empty when you start Skype for the first time. You can search for other Skypers from the worldwide Skype users list or you can enter a Skype user directly (eg, if they’ve emailed you with their skype name). Calling another Skyper You can either right-click or doubleclick a name in the contacts list or You can search the world-wide Skype user list for your friends and colleagues and authorize them to see when you’re on line. Or you can put in some parameter to search for (age, sex, language, location, etc) to find someone really interesting to talk to. 21st century penpals, perhaps? siliconchip.com.au ant Skype and Skypeout! – you can continue using it as you normally would while on line. In fact, you can even IM (instant message) a Skype user while you are talking to them if you want to share files, transfer inform ation, etc. Or you can use Skype itself to transfer files up to 2MB – while on a call! We understand even webcams and webcam software will still work while Skyping but system resources might come into play if your machine is towards the lower end of the range. Skype is in its infancy – it is currently V1.0 (until July 27th last it was in beta format!). More features have been promised in future releases. Calling a “real” phone is done using “SkypeOut”, another feature of Skype. Just a reminder (and SkypeOut will also remind you as you make the call) this is not free. But to most countries, including Australian numbers, it’s either significantly cheaper or dramatically cheaper to SkypeOut than to call on the phone. Remember too that calls are timed (to the minute). So talking to someone overseas for hours might not cost you an arm and a leg (as it would on the phone) but it will cost a finger or toe! SkypeOut calls to mobile numbers in many countries are just as cheap as calling fixed phones but SkypeOut calls to Australian mobiles will cost you about 28c per minute (as at August 1). As SkypeOut is European, calls are costed in Euros ($) and you have to convert them back to Aussie dollars. If you have a very short message to give someone locally on the phone (eg, a couple of minutes or so) it will even pay you to SkypeOut them rather than ring them. The minimum local call these days is about 15c – you can get five minutes of SkypeOut for that! Before you can call to fixed or mobile phones you need to establish a credit in your SkypeOut account. You do this by adding Euros to it via your credit card. If you don’t have a credit card then you can’t use SkypeOut (maybe it’s about time to get into the 21st century?). The choices are $10, $25 and $50 – roughly equivalent (Aug 1) to $AU17, $AU43 and $AU86. You have 180 days to use any balance remaining. Once you have a credit balance, you can call any number, anywhere. Use the same international dialling standards as you would for any “normal” international call: if you’re ringing a number in London, England, you’d dial +441(number). Of course, there’s no need for an international dialing prefix (0011 or whatever) – with SkypeOut you’re already in the international realm! Likewise, if you’re calling a number in Sydney, Australia – let’s say SILICON CHIP, you’d dial +61299795644, even if you are situated right next door. (The leading zero in the area code is always dropped in international dialling). And if you’re calling an Australian mobile (say 0404 999999), same rules apply: you dial +61404999999. If you forget that leading +, Skypeout will prompt you to put it in. There you have it. The very low-cost way to get very low-cost international, long distance, mobile and even local calls. If you get into trouble, SkypeOut has a very detailed help file along with FAQs, which should answer most of SC your queries. To make calls to fixed or mobile phones, you buy credits on-line (it’s a secure site) . . . . . . and you can check your account balance at any time. So far I’ve used Q0.03 (about 5c!) to make calls. Calling a standard phone Poor old Clem’s got only one friend... or maybe he hasn’t got around to putting them in his contacts list yet! search window to initiate a call. Note that Skype allows you to block calls as well, so if you’ve been a bad, bad boy (or girl) and someone has placed you on their blocked list, you’re out of luck. Answering a Skype call You’ll hear a phone ringing (surprise, surprise) and it’s up to you whether you answer or not. As soon as you accept the call, you can start talking. Either party can “hang up” or terminate the call at any time. Conference Skyping You can have a conference call of up to five people with Skype – again, all totally free if they are using Skype. You do this by holding down the control key and selecting the participants from your contacts list. When those contacts answer their Skype call, they immediately join the conference. You can also add another Skyper to join an existing call (conference or normal) by “inviting them to conference” (up to the five limit). If you are planning a conference call, get the person with the best internet connection to be the conference controller (ie, initiate the calls). Using your PC while Skyping Skype does not take over your PC siliconchip.com.au September 2004  13 WiFry: Cooking up 2.4GHz Antennas By the inscrutable Stan Swan As well as their celebrated discoveries of gunpowder and the compass, did the ancient Chinese stumble on microwaves? Did Ming Dynasty wizards then disguise the antenna as cookware to prevent such signalling secrets falling into barbarian hands? Does this also explain classical Asian expertise with “semiconductor” ceramics ? T here has recently been a flood of cheap USB WiFi “dongle” adaptors that have greatly stimulated 2.4GHz WiFi applications and experimentation. We obtained some from Dick Smith Electronics here in NZ – alas, DSE Australia appear to have decided not to stock these little beauties but they (or items very similar) are available from a variety of suppliers. (For those not fortunate enough to reside on the eastern islands [aka North Island or South Island], DSE NZ does do mail orders back to Australia [see contacts at the end of this article].) 14  Silicon Chip Given the line-of-sight (LOS) nature of microwave signals, obstructions from head high objects, partitions and vegetation may be at least partially overcome if the antenna can be mounted even a couple of metres or so higher, or at least clear of obstructions, away from noisy and shielding PCs into signal “sweet spots”. But extending WiFi antennas themselves (if at all possible) has normally involved an alphabet soup of costly cables and proprietary connectors (SMA, F, N, TNC, etc), with often significant microwave signal losses. So why not go the other way: put the USB WiFi adaptor (complete with its antenna) in a sweet spot and extend the USB cable? That way, all the 2.4GHz signal decoding to slower 12Mbps digital remains in the unit itself and although such “mast head massaging” will reduce final data rates, regular cheap USB fittings and cables then deliver Mbps rate signals to the PC. Experience indicates you may be able to add passive extensions up to the USB cable limit of 5m. Beyond this, an active USB extender should theoretically be used (but we have found it possible to go beyond 5m with quality cable and connectors). A beauty of the USB wireless approach is that it’s modular in one’s siliconchip.com.au Take one parabolic skimmer, a few hand tools and a USB cable . . . . . . determine the focal point (by maths or by trial and error) . . . . . . and mount the USB socket at the focal point, ready for the dongle . . . choice of device, not locking you into a particular standard. Unplug the 802.11b unit and just replace it with a faster USB 802.11g, 802.11a (heaven forbid), or Bluetooth adaptor. You could even swap out a memory stick, web cam, hub or IrDA adaptor of course ! Inspection of several USB adaptors reveals most have a short (~9cm) ceramic antenna soldered to the PC board with near-omnidirectional radiation patterns. Naturally modifying such a precision component involves con- siderable skill, so, given that design engineers had probably optimised performance anyway, it was decided to leave well alone and just explore gathering weak microwave signals at the antenna’s location. efficiently in one direction only. Homemade WiFi antenna designs now abound, many as variations on the infamous “Pringles” can, but construction techniques usually demand considerable attention to detail and fine metal working skills. Remember we’re trying to make things easier for those of you with two left hands! That brings us to the parabola. It can be regarded as a very efficient reflector. Were you alert during that High School parabola class? Well (just in case you did doze off . . .) parabolic reflectors A Parabolic Wifi antenna Most antennas consist of a “driven element” and one or more reflectors or directors which concentrate received signals onto that element. They do this at the expense of direction: high gain antennas invariably operate most . . .and here’s a prototype (not yet secured with the hose joiner) – a high-performance WiFi antenna that we’ve measured up to 15dB gain, giving an effective increase in range of several kilometres! A WiFi AP, 5km away on Somes Island in Wellingon Harbour (just visible behind the left side of the antenna) was readily accessed. siliconchip.com.au September 2004  15 shows this sweet spot – but take care – even under weak sunshine, such a small parabola can easily burn a finger or ignite paper. Don’t cook your WiFi adaptor in such a solar BBQ! (Don’t laugh: years ago Dick Smith sold such a device. And it worked!) Poor man’s WiFi? Don’t try this at home, kids: aiming a shiny parabola at the sun and putting your finger at the focal point is more than likely to result in a burnt finger! This method is one way of determining the focal point (just don’t aim it at the sun for too long!) have the unique property of a fixed focal point, unrelated to frequency, so that distant signals are surface reflected and delivered to a point, just as satellite dishes work Mmm – here’s an idea. If the parabola collects signals and focuses them on this point, what happens if we place a USB dongle (with its own “driven element”) in this position? Shouldn’t it benefit from concentrated WiFi signals, especially on reception (since some transmissions may not “illuminate” the parabola and be lost). Recall the maths relating focal point to dimensions of the parabola? No? (Aha! You were asleep!).You can find the focal point of a parabola with this simple formula: FP = D2 16 x c where FP = focal point distance from centre, D=dish diameter, and c= depth from rim to centre (all in mm) For a 300mm diameter dish, this yields a focal point at 94mm out from the centre. You can also determine the focal point of a parabola with the “visible light” technique. If you press some shiny aluminium cooking foil to the parabola’s shape and note where the reflections are brightest, you’ve found the focal point. Bringing the sun to a focus readily After assorted DIY parabolas were developed, many web-inspired as conductive foil glued to curved cardboard, a chance visit to a Chinese emporium revealed diverse Asian cookware of seductive profile. Other customers gave bemused glances as assorted woks, lids and pans were measured up & focal points calculated! Although tempting, normal woks are of course very solid and may have serious wind resistance – a major factor in exposed outdoor sites such as here in coastal NZ. But behold – a range of parabolic cooking vat scoops, complete with user-friendly bamboo handles, that are cheap, sturdy, of fine galvanised open mesh, that mate with a USB dongle beautifully. Chinese students here inform me that such classic cookware items are known as “Spider Skimmers” and come in imperial sizes: 6”, 8” and 9”, with the largest 12” (300mm) as we eventually used. Now you know why we called this article “Wi Fry!” The mesh gaps approximate 5mm, and as 2.4GHz signals have a wavelength of some 125mm, these spaces are well inside the 12.5mm limit that RF theory relates to 1/10th of a wavelength. Extensive field testing by IT students from Massey Netstumbler or WiFiFoFum,(the PDA equivalent) are University (Wellington, NZ) have proved just how effective invaluable programs for WiFi antenna tweaking. 2.4GHz this little WiFi antenna is. Many have built their own! signals often wander 5dB in strength or reflect randomly. 16  Silicon Chip siliconchip.com.au Here’s an alternative: mount a bracket on the skimmer handle which places the dongle at the parabola focus (also known as the “sweet spot.” Saves butchering your scoop! Mating of such ancient (food) and modern (electronics) items is yet to be Feng Shui assessed but subsequent performance of the hybrid has been most promising ! Finishing off involved prowling hardware stores for antenna dongle holders. A garden hose mender was found to make a perfect support for the USB socket, with only modest mesh trimming needed if rear mounted. A hack saw angled slice cut in the hose mender allows USB cable placement which the screw-on rings later secure. The plug-in USB adaptor even fits in the recess at just on the desired focal point too, when internal joiner plastic trimmed or drilled off to suit. Performance In spite of its simple homemade design, this antenna certainly cuts the mustard (soy?) and extensive testing and feedback verifies a 15dB gain is readily achieved with a 12” scoop. Most tweaking has been done with the latest release ( Ver 0.4) of NetStumbler, which thankfully now supports most WiFi adaptors, as its graphing features have proved invaluable. Since every 6dB gain equates to doubling the line of sight coverage, 15dB siliconchip.com.au The technique is not limited to wifi: mobile phones, wireless PDAs, in fact a variety of “receiving” equipment can benefit from having a parabolic dish focus signals. gain over a bare adaptor means some 6-8 times range extension is feasible. Most bare dongles only stretch to about 500m LOS, so some 3km (6 x 500m) can be expected with a scoop. With one at each end 5–8km point to point links should be possible at good data rates, making feasible broad band Internet sharing, streaming video, multiple voice traffic channels or even impromptu/emergency conferences. Enthusiasm for this USB approach has been immense, testified to by some 150,000 site visits in a few weeks, and the design seems to have struck a democratic chord globally. For experimenters on tight budgets, this “Poor Man’s WiFi” USB approach looks a winner. Other apps Earlier on we mentioned that the parabolic dish was independent of frequency (remember the “Sooper Snooper” audio parabolic microphone published in SILICON CHIP in September 2001). So we figured mobile phones, wireless PDAs, and so on would also benefit from similar treatment. Our research proves that they do: some mobile phone signals that wouldn’t even register on the LCD suddenly became usable! Just one tip: don’t use a polished dish and cook your mobile phone! SC References and URLs: 1. www.usbwifi.orcon.net.nz    Project web site, with many pictures, lab. notes, case studies, links and more technical references. 2. www.dse.co.nz Dick Smith Electronics (NZ) – stockists of the ZyDAS ZD1201 based XH6822 and XH6859 adaptors. Dick Smith Electronics Australia (www.dse.com.au) stock a similar XH4268 “Spirit” for ~ $AU50 that’s been reported to work just as well. 3. www.netstumbler.com WiFi signal auditing software, Netstumbler Ver 0.4 4. www.wififofum.org WiFiFoFum PocketPC 2003 WiFi scanner 5. www.component.tdk. com/2.4GHAnntena.pdf Ceramic antenna technical details September 2004  17 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 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. USB-powered PIC programmer This simple circuit can be used to program the PIC16F84 and similar “flash memory” type parts. It uses a cheap 555 timer IC to generate the programming voltage from a +5V rail, allowing the circuit to be powered from a computer’s USB port. The 555 timer (IC1) is configured as a free-running oscillator, with a frequency of about 6.5kHz. The output of the timer drives four 100nF capacitors and 1N4148 diodes wir- CONTRIBUTE AND WIN! 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! 24  Silicon Chip ed in a Cockroft-Walton voltage multiplier configuration. The output of the multiplier is switched through to the MCLR/Vpp pin of the PIC during programming via a 4N28 optocoupler. Diodes ZD1 and D5 between the MCLR/Vpp pin and ground clamp the output of the multiplier to about 13.6V, ensuring that the maximum input voltage (Vihh) of the PIC is not exceeded. A 100kΩ resistor pulls the pin down to a valid logic low level (Vil) when the optocoupler is not conducting. The circuit is compatible with the popular “JDM” programmer, so can be used with supporting software such as “ICProg” (see www. ic-prog.com). Luke Weston, Wycheproof, Vic. ($50) siliconchip.com.au Economical desk lamp for camping This LED lamp was originally designed for use on a budget solarcharged 12V electrical system. It is bright enough for comfortable reading at night and features constant LED brightness with diminishing battery voltage. The circuit uses six high-brightness white LEDs mounted in a 90mm diameter reflector. The upper half of a stainless steel ice cream bowl makes a good reflector but almost any torch reflector of a similar size will do. As shown, two banks of three series-connected LEDs are powered from a 12V (nominal) DC supply. The LEDs used are rated at 20mA maximum with a measured voltage drop of 3.2V. Each bank combines an inexpensive LM334 current source IC with a BC558 transistor to provide a constant 20mA to the LED string. Basically, the LM334 controls the base current of the BC558 such that 64mV appears between its “R” and “V-” terminals. With the 3.3Ω resistor shown, this results in close to the desired 20mA through the LEDs. The components can be mounted Quartz clock flasher protects equipment Damage to battery-powered devices when unintentionally left on is common. The battery runs down, leaks and causes widespread destruction. This simple device, based on a quartz clock movement, flashes two LEDs to indicate when power is switched on. It’s small, uses little power and costs only a few cents to build. siliconchip.com.au on a small piece of Veroboard. An old desk lamp makes an ideal body, with a metal disc used to cover the hole left after the 240V lamp fitting is removed. The metal disc can also be used to mount the power switch and rubber grommet for the power supply leads. Three M3 screws and nuts spaced 120° apart keep the reflector in place. John Amos, Kanahooka, NSW. ($35) Extract the circuit board from a discarded quartz clock. Disconnect the coil and its fittings, noting the pads that it is connected to. The circuit shown can then be connected across the pads. The circuit requires a 3V supply rather than the original 1.5V used by the clock movement. However, long testing has shown that it works reliably at this higher voltage level. When powered up, each output goes low in turn, with the LEDs flashing alternately for 30ms at one-second intervals. In the prototype, surface-mount LEDs (ex-equipment) were mounted on a bit of strip board and stuck to the clock board with double sided sticky tape. You could omit one LED and have a flash every two seconds to further conserve power. This circuit could have other uses, such as in a model railway layout, a flashing badge, or as a reminder for all sorts of things. The LEDs could be inside opto-isolators, rather than discrete components, opening up a wide range of possible uses. Old quartz clocks are often available from school fates and scout jumble sales for a song. It doesn’t matter if the face is damaged or the hands are mangled – you only need the movement! A. J. Lowe, Bardon, Qld. ($30) September 2004  25 Circuit Notebook – continued '-----------------------------------------------' Two switches on one pin demonstration '-----------------------------------------------read_S1: low 1 'discharge capacitor input 1 if pin1 = 1 then S1_pressed low 2 'turn off LED1 goto read_S2 S1_pressed: high 2 'turn on LED1 read_S2: high 1 'charge capacitor input 1 if pin1 = 0 then S2_pressed low 4 'turn off LED2 goto read_s1 Two switches share one pin This circuit and program show how you can read two switches from a single I/O pin of a PICAXE-08. As shown, the program simply echoes the states of the switches on the LEDs. To test if switch S1 is pressed, the program first sets P1 as a low output to discharge the 100pF capacitor. The pin is then reconfigured as an input and read. If the pin is low, the capacitor is still discharged, meaning S1 is not pressed. Conversely, if the pin reads high, the capacitor has been charged, in- Multi-level lock system This circuit is a simple yet versatile adjustable lock. It can be used either on its own or as part of a much larger multi-level lock system. There are many situations in which certain employees need to be granted access to select areas of a building. Using conventional lockand-key security, this necessitates the issuing of large numbers of keys. It also means that the persons who have the greatest freedom of movement must carry the largest number of keys. A less obvious yet potentially significant problem is that of security. 26  Silicon Chip dicating that S1 is pressed. The procedure for testing S2 works in reverse. The program first sets P1 as a high output, which charges the 100pF capacitor. Again, the pin is switched to an input and read. If the pin is high, the capacitor is still charged, so S2 is not pressed. However, if the pin reads low, the capacitor has been discharged, so S2 is pressed. If both switches are pressed at the same time, the result is indeterminate. This usually isn’t a problem if momentary pushbutton switches are used but it does make the scheme unsuitable for use with latching type toggle and slide switches. To select the right key out of, say, a dozen in an emergency could present an unacceptable delay. Besides this, readers will already be familiar with the problem of keys needing to be cut and locks needing to be changed. All of these problems are S2_pressed: high 4 goto read_S1 'turn on LED2 The capacitor is only necessary to make the arrangement more reliable. Even without it, the input capacitance and impedance of the I/O pins on the PICAXE-08 are sufficient to hold the previous input voltage long enough for the program to work. This idea will work with other PICs, such as the 16F84, but not with other PICAXE chips, as they do not have bidirectional I/O pins. Andrew Partridge, Kuranda, Qld. ($30) obviated with the use of an electronic multi-level lock system, such as the one described here. The “key” consists of a single resistor housed inside a mono jack or DC plug. A simple window comparator is used to detect a valid key. Fig.1: this diagram shows how to combine several circuits to provide a multi-layer system. siliconchip.com.au If the value of the resistor lies between the values of VR1 (the lower cut-off) and VR2 (the upper cut-off), the lock is opened. If any other value resistor is wired to the plug – or none at all – an alarm sounds. While this does not guarantee the highest level of security, it arguably equals the security of metal keys, since the only way to be sure that you will not trigger the alarm is to obtain a copy of an original key. Apart from this, the chances of triggering the alarm are very high. The main part of the circuit (IC1 & IC2) is not powered until a “key” is inserted. This saves power and also enables simple open-circuit key detection. Without a key in the socket, the gate of Q2 is grounded through the normally closed contacts of the socket (SKT1). Therefore, Q1 is held in the “off” state by the 100kΩ resistor between its base and emitter. When a key is inserted, ground is lifted from the gate of Q2 and it is pulled high through the 1MΩ resistor. Q2 then conducts, proving base current for Q1 and powering up the remainder of the circuit. A dual op amp (IC1) makes up the window comparator. It determines whether the key lies above or below the potential of its two non-inverting inputs. One element of a 4093 quad NAND gate (IC2a) combines the results, going low at pin 3 if the key “fits”. A second NAND gate (IC2b) inverts the result at pin 4, taking Q3’s gate high. This illuminates the LED and powers a relay or solenoid. On the other hand, if the key doesn’t fit, pin 3 of IC2a goes high, also driving the gate of SCR1 high. A 47kΩ resistor and 47µF capacitor in the gate circuit provide a short delay, after which the SCR fires, illuminating LED2 and sounding the alarm. Since the SCR latches when activated, the alarm will sound continuously until de-activated by pressing S2 or disconnecting power. S1 is most likely to be used as an indoor pushbutton to release the lock on exit but could also serve as an emergency switch if the key is lost. Fig.1 shows how several circuits may be combined to provide a multilevel system of entry or authorisation. continued on page 29 siliconchip.com.au September 2004  27 Circuit Notebook – continued PICAXE-controlled battery charger This circuit converts a cheap car battery charger into an automatic charger. It includes the following features: • Reverse battery protection (green LED flashes). • Battery connected and no power to charger (green LED flashes). • Battery not connected and charger on (green LED flashes). • Charging indicator (red LED on steady). • Charged indicator (green LED on steady). The PICAXE-08 microcontroller (IC1) is powered from REG1, a 78L05 +5V regulator. When charger power is present, REG1 receives power from the output side of the bridge rectifier via D1. Alternatively, when the charger is switched off, power is derived from the battery via D3. Depending on the terminal voltage of the battery, the PICAXE will connect or disconnect the battery from 28  Silicon Chip the charger output using RLY1. Power for the relay coil is provided via a separate +12V regulator (REG2). Unlike the +5V regulator, REG2 receives its power from the AC side of the bridge. This is necessary to prevent RLY1 staying on if charger power is removed and the battery is on charge (RLY1 contacts closed). The presence of charger and battery power is sensed by the PICAXE on digital inputs P5 (pin 2) and P4 (pin 3) respectively. Both inputs utilise voltage divider networks to ground so as not to exceed the maximum input voltage of the port pins. Input P4 also includes a zener diode (ZD1) clamp for protection in the case of reversed battery leads. Battery voltage is sensed on analog input P6 (pin 1) after being divided down by 10kΩ and 2.7kΩ resistors. The PICAXE program monitors the battery voltage using this input and the readadc command to determine the correct connect and disconnect voltages. The program listing is on the facing page. Ray S As shown, is this monter it initiates winner onth’s Peak At of the charging at las L about 13.1V Meter CR and disconnects at about 14.1V. To prevent rapid relay switching when the battery is fully charged, a 5-second delay has been included after each disconnect. After five consecutive “disconnect” cycles, the program “sleeps” for about one hour before resuming. At any point in the program, reverse battery connection, no battery connected, charger power on, battery connected and charger power off events are detected. If any of these events occur, the battery is disconnected and the green LED will flash. The circuit and program can easily be modified to suit individual needs. All parts except the PICAXE came from my “useful” box. Ray Sonter, Bundaberg, Qld. siliconchip.com.au PICAXE-Controlled Charger: Program Listing 'Picaxe-08 controlled lead-acid battery charger start: low 0 low 4 b1=0 b2=0 b3=0 'red charge 'green charged red: if pin3=0 then flash if pin2=0 then flash readadc 1,b0 if b0>155 then count low 4 high 0 goto red 'reverse polarity protect, no battery 'charger not turned on & battery connected 'read battery voltage 'about 14.1V, disconnect 'green led off 'charge connect count: b1=b1+1 if b1>5 then delay ‘count # of connect to disconnect cycles green: b2=0 b3=0 low 0 high 4 wait 5 if pin3=0 then flash if pin2=0 then flash readadc 1,b0 if b0<140 then red goto green flash: high 4 pause 100 low 4 pause 100 goto start delay: b1=0 if pin3=0 then flash if pin2=0 then flash low 0 high 4 pause 1000 b2=b2+1 if b2>59 then onehour goto delay onehour: b3=b3+1 if b3>59 then green b2=0 goto delay siliconchip.com.au 'charge disconnect 'green led on Multi-level lock continued from page 27 As shown, Key 1 contains a 10kΩ resistor and Key 2 a 22kΩ resistor. Lock 1 admits keys between 4.7kΩ and 15kΩ, while Lock 2 admits keys between 4.7kΩ and 27kΩ. Key 1 thus opens both locks, while Key 2 opens only Lock 2. Similarly, Key 3 contains a 47kΩ resistor, while Lock 3 admits keys between 33kΩ and 56kΩ. Thus, Lock 3 excludes both Keys 1 and 2. If a solenoid is used for the lock, take care to ensure that it is not energised for longer than specified by the manufacturer. Q3 is rated at 12A, SCR1 at 2A and D1 at 3A, so any solenoid, relay or alarm should not exceed these parameters – which they are unlikely to do. The lock uses just 200µA on standby and so could run for months at a time from a suitable 12V battery. Thomas Scarborough, South Africa. ($45) 'about 13.1V, go to charge 'green led flashes 'battery reversed, no battery or 'charger not on & battery connected 'one second 'about one minute 'about one hour September 2004  29 For dry beds and undisturbed sleep . . . Be instantly alerted when your toddler is about to wet the bed. This device will help train your child by immediate waking, before the bed is wet. Build this project and look forward to a happier child, dry beds and undisturbed sleep. Bed Wetting Alert by JOHN CLARKE F REQUENT BED-WETTING can be a real problem for many children. Occasional bed wetting by toddlers and young children is normal and can be tolerated but it can be a problem when it becomes a regular occurrence. Ultimately, it is in the best interest of the child to learn how to have a dry night’s sleep without the unpleasantness of waking up saturated and needing to have all the bedclothes changed. From the parents’ perspective, there is the constant work of extra washing of sheets, pyjamas and bedding after each bed-wetting incident has occurred. Commercial bed-wetting alarms are available but typically they involve the use of an aluminium foil under-sheet. They do work but the child and bedding still ends up being wringing wet 30  Silicon Chip and you still have to go through the process of changing wet bedclothes in the middle of the night. This is the big advantage of our new Bed-Wetting Alert. It detects the immediate presence of wetness in the child’s nappy and sounds the alarm to awaken the child who can then toddle off to the toilet. If not, the alarm will continue to sound at a much lower level, indicating to the parent there has been an alert condition which requires attention. The Bed-Wetting Alert comprises a key-fob sized transmitter and a receiver. The transmitter has an attached Velcro sensor strip with embedded wires to sense wetness in the child’s crotch and this causes the alarm to sound. The transmitter can be clipped to the hip section of the nappy or pyjama pants or placed inside the pocket of the pyjama pants. The hook side of the Velcro secures well to brushed cotton (flannelette) material and nappies. As soon as the sensor detects even a small amount of dampness, the transmitter sends a signal to the receiver to sound the alarm. The alarm sounds loudly for about 10 seconds before dropping in level. Should the alarm not wake the child, it will continue sounding at a low level until the sensor strap is dry or is removed, or the receiver is switched off. In order to be able to use a very compact transmitter module, we decided to base the circuit on Jaycar’s Secret Farter (Cat. GH-1088, $19.95). While this device has a trivial purpose, it is really a useful transmitter and receiver that sounds (!) when ever the transmitter button is pushed. As already noted, siliconchip.com.au Fig.1: this is the modified transmitter. It uses MOSFET Q4 to turn it on in response to low resistance (moisture) across the sensor inputs. the transmitter is housed in a small key fob style case, while the receiver is housed in a compact case with four AAA cells and a 50mm loudspeaker. The project assembly involves fitting a small PC board into the receiver case and replacing the transmitter’s PC board with a new unit which uses most of the transmitter parts. Transmitter circuit The circuit for the Bed-Wetting Alert transmitter is shown in Fig.1. It comprises a multivibrator using transistors Q1 & Q2 and an RF oscillator using transistor Q3 which operates at 304MHz. The circuit is powered from a 12V lighter battery. MOSFET Q4 is switched on when its gate voltage goes above about 3V. Normally, the gate is held at 0V by the 1MΩ resistor. However, when the sensor wires become wet, current flows from the 12V supply via the 100kΩ resistor, between the two sensor wires and via the second 100kΩ resistor and this pulls Q4’s gate high so that it can conduct and turn on the transmitter. Diode D2 is there to protect the gate siliconchip.com.au if the battery is inserted the wrong way around, while diode D1 protects the rest of the circuit if the battery is wrongly connected. The 10nF capacitor is included to prevent noise from switching on the MOSFET. When power is applied to the oscillator part of the circuit, the multivibrator starts and produces a 200Hz signal at the collector of transistor Q2. This waveform is used to turn on and off the RF oscillator comprising Q3, trimmer VC1, the L1 tuned circuit and the feedback applied to Q3’s base via the 2pF capacitor. The transmitted RF signal becomes bursts of 304MHz signal at a 200Hz rate. Bed-Wetting Alert circuit The receiver for the Bed-Wetting Alert is based on the Secret Farter. We will not describe its operation here but suffice to say that whenever the receiver detects the transmission signal, it produces a positive voltage to cause the on-board sound generator/ amplifier to drive the speaker. We use this positive voltage as the control input for the Bed-Wetting Alert Sounder The project uses Jaycar’s Secret Farter to obtain a low-cost transmitter and receiver. circuit which is shown in Fig.3. It is designed to produce a modulated tone when activated and this signal lasts for around 10 seconds before dropping to a lower sound level. The circuit is September 2004  31 Fig.2: this is the block diagram for the receiver circuit. It requires a few modifications, including the removal of the sound processor and amplifier (IC2), as shown here. based on a 4093 quad 2-input NAND gate Schmitt trigger package. Two of the NAND gates are connected as oscillators. IC1c is a tone oscillator operating at about 500Hz, as set by the 10nF capacitor, trimpot VR2 and the 100kΩ resistor from pin 10. IC1c does not oscillate continuously but is controlled by IC1a and IC1d, the gating oscillator which makes IC1c deliver a beep beep beep (about twice a second) instead of a continuous tone. Initially, when the control input is low (0V), transistor Q1 is off and the inputs to IC1a will be pulled high via the associated 1MΩ resistor. Pin 3 of IC1a is therefore low (0V) as is pin 12, so IC1d cannot oscillate. Because pin 12 of IC1d is held low, pin 11 stays high and it lets IC1c oscillate, which is not what we want. Therefore, D2 is connected between pin 8 and pin 3 so that when pin 3 is low, IC1c cannot oscillate either. When the receiver picks up a signal from the transmitter, the control input goes high, Q1 turns on, pin 3 of IC1a goes high and both oscillators start running. The gated tone oscillator signal is fed to the complementary buffer of transistors Q2 & Q3 and these drive the loudspeaker via a 22µF nonpolarised capacitor. Transistor Q4 provides a volume control for the Alert Sounder. When Q1 turns on to allow both oscillators to run it also pulls pins 5 & 6 low via the associated 10µF capacitor and so pin 4 of IC1b goes high. This turns on Fig.3: the Alert Sounder initially sounds the alarm for 10 seconds in response to the receiver’s control signal. It then drops to a lower level as Q4 is turned off. 32  Silicon Chip siliconchip.com.au Q4 so that it carries the full speaker current. After about 10 seconds, the 10µF capacitor is fully charged and so pins 5 & 6 are pulled high again via the associated 1MΩ resistor. Thus, Q4 turns off and the speaker is muted to a low level, by virtue of the much smaller current that now flows via its 1kΩ resistor to the +5.4V supply. The low-level sound continues until the power is switched off or the control input goes low. Construction As noted above, this project is based on Jaycar’s Secret Farter. The transmitter needs to be rebuilt onto a new PC board coded 15109041 and measuring 30 x 45mm. This board then fits into the original transmitter case and runs from the same 12V battery. A second PC board, coded 15109042 and measuring 57 x 42mm, is fitted into the receiver case behind the loudspeaker. Before starting, check that your Secret Farter works by inserting the batteries, switching on the receiver and pressing the transmitter switch to make a “socially inappropriate rude noise” – we can’t bring ourselves to say “fart” in this family magazine! If it doesn’t operate, check the batteries, as they may be flat. Having confirmed that the unit operates, construction can proceed. Start by checking the PC boards for any undrilled holes or breaks or shorted connections in the copper tracks. Fig.4 shows the component layouts for both the transmitter PC board and the Alert Sound board. Note that the hole on the transmitter PC board between the sensor connections and inductor L2 needs to be 3mm in diameter for the case securing screw. There are no mounting holes for the Alert Sounder PC board as it is held in position behind the loudspeaker once the case is assembled. Remove the parts one by one from the original transmitter and place them Fig.4: the new transmitter board (left) uses all the components from the Secret Farter transmitter board, except for the switch, LED and the 2.2kΩ resistor. At right is the parts layout for the Alert Sounder board. It uses low profile “skeleton” trimpots, while three capacitors need to be laid on their sides as shown in the photo below. The photo at right shows the completed transmitter board, while below is the modified receiver unit fitted with the Alert Sounder board. Table 1: Resistor Colour Codes o o o o o o siliconchip.com.au No.   3   4   3   2   1 Value 1MΩ 100kΩ 10kΩ 1kΩ 10Ω 4-Band Code (1%) brown black green brown brown black yellow brown brown black orange brown brown black red brown brown black black brown 5-Band Code (1%) brown black black yellow brown brown black black orange brown brown black black red brown brown black black brown brown brown black black gold brown September 2004  33 transistors and capacitors. Note that the electrolytics must be oriented correctly except for the 22µF NP (nonpolarised) one. The three capacitors near IC1 also need to be laid over on their sides to allow clearance for the loudspeaker – see photo. Receiver modifications The sensor strap is made by threading two 0.2mm tinned copper wires (8A fuse wire) through the loops on a Velcro cable tie – see Fig.5. The wires are then fed through to the other side of the strap at the end with the pink loop. Each wire end is terminated to the shorting link in a jumper shunt. They are then connected via a 4-pin SIL header and 2-wire cable to the transmitter. This shows the completed moisture sensor and its companion transmitter unit. in the new PC board, making sure they are placed correctly and mounted as close to the board as possible, otherwise the lid will not fit. Note that there will be three parts left over: the switch, LED and 2.2kΩ resistor. Once all the original parts from the transmitter are placed on the new PC board, insert and solder in the remaining new parts. MOSFET Q4 also needs to be mounted squashed down on the PC board. For the Alert Sounder board, install the IC, resistors, diodes and trimpots first. Take care to orient the diodes and IC correctly. The specified trimpots are the skeleton type, not cermet. These are used to keep the component height as low as possible. The higher cermet type trimpots will not allow the case to be assembled since they will foul the loudspeaker. Next, install the PC stakes, the Before installing in the Alert Sounder board in the receiver, check that the new transmitter works. Do this by shorting the two sensor terminals with a wet finger or a screwdriver. In some cases, you may need to adjust trimmer capacitor VC1 ever so slightly to get the unit to transmit on the right frequency for the receiver. Do not move the trimmer by much before testing again. If the unit doesn’t work by turning the trimmer one way, try moving it the other way. Now remove the batteries from the Secret Farter receiver and then remove the PC board by taking out the two selftapping screws holding it to the rear of the battery holder. There are two ICs on this board, a dual in-line LM324 and a single in-line 6-pin IC which is the fart sound generator (IC2). This must be removed. Fig.6 shows how the board will look after modification. Remove the glue around IC2 and then desolder it from the PC board, as well as the loudspeaker wires. That done, replace C16 (4.7µF) with a 100µF 16V PC electrolytic. This capacitor needs to be laid over at about 45° to allow the case lid to fit. Make sure its polarity is correct, then solder a 100kΩ resistor across resistor R23. Next, attach wires to the GND and Control pads where the sound IC was mounted and to the +6V terminal on the slide switch. Pass the wires through the slot in the PC board. Reattach the PC board to the rear of the battery holder. Now place the Alert Sound board into the receiver case and wire up the GND, Control and +6V wires to Issues Getting Dog-Eared? Keep your copies safe, secure and always available 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 & mail the handy order form in this issue; or fax (02) 9979 6503; or ring (02) 9979 5644 & quote your credit card number. 34  Silicon Chip siliconchip.com.au Parts List 1 transmitter PC board coded 15109041, 30 x 45mm 1 Alert Sounder PC board coded, 15109042, 57 x 42mm 1 Secret Farter (Jaycar GH1088) 1 pack Velcro cable ties 25 x 140mm (Jaycar HP-1210) 2 shorting plugs for 0.1-inch spaced header 1 4-way header plug 7 PC stakes 1 600mm length of light gauge figure-8 flexible wire 1 300mm length of 0.2mm tinned wire 1 100mm length of red light duty hookup wire 1 50mm length of white light duty hookup wire 1 50mm length of brown light duty hookup wire 1 100mm length of light duty figure-8 cable 1 10mm length of 3mm diameter heatshrink tubing 1 10mm length of 20mm diameter heatshrink tubing 1 100kΩ horizontal mount skeleton trimpot (VR1) 1 1MΩ horizontal mount skeleton trimpot (VR2) Fig.5: assemble the sensor strap as shown here. It is made from a Velcro cable tie, 0.2mm tinned copper wire (8A fuse wire), a 4-pin SIL header and two jumper shunts fitted with shorting links. the PC stakes. Also connect up the loudspeaker using the original speaker wires. Re-insert the batteries and check that the alarm works when the transmitter sensor contacts are shorted as before. If it doesn’t work, check the supply to IC1. There should be about 5.4V between pins 7 & 14. Trimpots VR1 and VR2 can then be adjusted to your preferred sound. Sensor strap The sensor strap is made using two Velcro cable ties (Jaycar Cat HP-1210), a 4-way pin header and two shorting siliconchip.com.au plugs. A short length of 2-way rainbow cable (eg, figure-8) connects between the transmitter sensor terminals to the header plugs. The shorting plugs act as connectors on the sensor strap assembly. Fig.5 shows the details. The Velcro cable ties consist of a strip of black Velcro with a square of yellow Velcro hook material at one end. The first job is to cut the yellow square off one strip and sew it onto the vacant end of another Velcro cable tie. The Velcro hooks will anchor well to the inside of flannelette pyjamas or a nappy. Semiconductors 1 4093 quad 2-input Schmitt NAND gate (IC1) 1 BC547 NPN transistor (Q1) 2 BC337 NPN transistors (Q2,Q4) 1 BC327 PNP transistor (Q3) 1 2N7000 N-channel MOSFET (Q4 on transmitter board) 1 1N4004 1A diode (D1) 2 1N4148 diodes (D2,D3) Capacitors 4 100µF 16V PC electrolytic (1 required for the Secret Farter receiver) 1 22µF NP or BP electrolytic 2 10µF 16V PC electrolytic 2 10nF ceramic (.01µF code 103 or 10n) Resistors 3 1MΩ 4 100kΩ (1 required for the Secret Farter receiver) 3 10kΩ 2 1kΩ 1 10Ω September 2004  35 Fig.6: this diagram shows the modifications required to the Secret Farter receiver board. Note that IC2 (the amplifier) must be removed. Fig.7: here are the actual size artworks for the two PC boards. Now sew two lengths of 0.2mm tinned copper wire (ie, 8A fuse wire) to the loop side of the Velcro strip and terminate each wire at the end with the material loop tag to a shorting plug. In each case, loop the wire through the side hole in the plug and around the exposed metal bridge. Note that the shorting plugs are to be located on the hook side of the Velcro and are secured to the Velcro using cotton thread. The two shorting plugs are placed side-by-side and sewn securely using the side hole to locate the piece and covering over with cotton to tie down the plugs. Since the Velcro cable straps come in packs of five, you can make two sensor straps, so that one can be washed while the other is being used. The 4-way header is used to make the connections to the figure-8 cable from the transmitter sensor terminals. The wires can be soldered as shown, with the whole assembly covered in some heatshrink tubing. The plug is passed through the material loop at the end of the Velcro strap and wrapped around this before being plugged into the two shorting plug sockets on the sensor. This will prevent the cord from pulling out. The wire length should be only as short as necessary to avoid it becoming tangled with the child’s limbs. The wiring into the transmitter should be protected with a sheath of heatshrink tubing at the point where the cable exits the case. You will need to file a small diameter hole in the base and lid of the transmitter case using a rat-tail file to allow clearance for the connecting cable. In use, the child should wear two pairs of pants or a pair of pants plus a nappy. The Velcro sensor strap is placed between the two pants, in the crotch area, with the hook side of the strap fastened to the nappy. You can locate the transmitter case either near th hip using the clip on the case or it can go in a pocket. The receiver should ideally be placed close by the bed so the child will hear the alarm. Of course, the whole procedure should be fully explained to the child, to help in the training process. Hopefully, after a couple of weeks, it can be dispensed with but if it has to be used for a long period, battery life in the transmitter should be quite good. However, the batteries in the receiver case may have to be replaced more often, as the alarm volume drops. The photo at left shows the modified Secret Farter receiver board, with the external wiring connections to the new Sounder Board. The photo at right shows how the +6V connection is made to the underside of this board. 36  Silicon Chip siliconchip.com.au Fig.8: the Doorbell Sounder is based on a 7555 to produce a Ding Dong tone. You’ve had your fun – now convert it to a wireless doorbell T HIS PROJECT is also based on Jaycar’s Secret Farter. After you’ve had your fun with it, turn it into something useful – a wireless doorbell. You can place the door-bell receiver anywhere in your house or backyard so that it can be easily heard where you are located. There are plenty of times when it is impossible to hear if the doorbell rings. You may be entertaining or just relaxing and miss hearing someone is at the front door. In fact, it is often invited guests who have the most trouble in making their arrival noticed. A wireless doorbell can help solve this. The receiver is battery-powered so that it is portable and this makes it ideal for occasional use. When used as a permanent doorbell receiver, it should be powered from a 6V DC plugpack rated at 100mA. No modifications are required for the remote transmitter fob. It can be installed at the front door like any other doorbell switch but it is easier to do than with a wired doorbell, as no wires need to be passed through siliconchip.com.au OK, you’ve shocked Aunt Martha, mortified your granny and severely embarrassed your fairy godmother! Now that you’ve had your fun, you can convert your Secret Farter to something really useful – this Wireless Doorbell. September 2004  37 Fig.9: the component layout for the Doorbell Sounder. Fig.10: this is the full-size etching pattern for the PC board. the wall. The transmitter is powered by a 12V lighter battery. A Doorbell Sounder PC board needs to be added inside the receiver case. As mentioned earlier in this article, Q2 and Q3. These in turn drive the loudspeaker via the 10µF capacitor and 10Ω resistor. At the same, the positive control signal turns on transistor Q1 which pulls pin 5, the modulation input, down to a level set by trimpot VR1. This sets the initial oscillation frequency. When the transmitter button is released, the control signal goes low, Q1 is switched off and pin 5 rises back to a level set by the resistors at pin 5. This reduces the frequency produced by IC1 and its tone continues until the voltage at pin 4 drops to about 1V. The result is the characteristic DingDong tone. the Secret Farter receiver produces a positive voltage whenever the transmitter switch is pressed. This is used to control the Doorbell Sounder circuit which is shown in Fig.8. It comprises a single 7555 timer (IC1) that produces two separate tones, one when the transmitter button is pressed and the second when the button is released. Initially, when the control input is low (0V) pin 4 (reset input) of IC1 is low and so the output at pin 3 is low and the loudspeaker is mute. When the transmitter button is pressed, the receiver’s control input goes high and pin 4 is pulled high via diode D2 so that IC1 can oscillate. Its tone output at pin 3 drives the complementary buffer comprising transistors Construction The Doorbell Sounder PC board is coded 15109043 and measures 57 x 42mm. It fits into the receiver case behind the loudspeaker. Its component layout is shown in Fig.9. The proce- Table 2: Resistor Colour Codes o o o o o o No.   3   1   1   2   1 38  Silicon Chip Value 1MΩ 470kΩ 330kΩ 100kΩ 10Ω 4-Band Code (1%) brown black green brown yellow violet yellow brown orange orange yellow brown brown black yellow brown brown black black brown 5-Band Code (1%) brown black black yellow brown yellow violet black orange brown orange orange black orange brown brown black black orange brown brown black black gold brown siliconchip.com.au Parts List This shows the assembled PC board. Note how some of the parts are bent over to provide clearance. dure for installing it into the receiver is the same as for the Bed Wetting Alert with two exceptions, First, capacitor C16 on the receiver board is changed from 4.7µF to 22µF (not 100µF as used in the Bed Wetting Alarm). And second, there’s no need to parallel R23 with a 100kΩ resistor. The receiver can be placed anywhere within a 15m radius of the doorbell. For long term use, the receiver should be powered from a 6V DC plugpack rated at 100mA or more. If you do this, remove the batteries and attach a DC socket to the receiver suitable for the plugpack connection. Finally, the receiver and doorbell circuit are protected against reverse polarity connection so if you reverse connect the plugpack, it will not cause SC any damage. 1 PC board coded, 15109043, 57 x 42mm 1 Secret Farter (Jaycar GH1088) 5 PC stakes 1 100mm length of red light-duty hookup wire 1 50mm length of white lightduty hookup wire 1 50mm length of brown light duty hookup wire 1 50mm length of 0.7mm tinned copper wire 1 1MΩ horizontal mount skeleton trimpot (VR1) REAL VALUE AT $12.95 PLUS P & P Semiconductors 1 7555 timer (IC1) 1 BC547 NPN transistor (Q1) 1 BC337 NPN transistor (Q2) 1 BC327 PNP transistor (Q3) 1 1N4004 1A diode (D1) 1 1N4148 switching diode (D2) These binders will protect your copies of S ILICON CHIP. They feature heavy-board covers & are made from a dis­ tinctive 2-tone green vinyl. They hold up to 14 issues & will look great on your bookshelf. Capacitors 2 100µF 16V PC electrolytics 1 22µF 16V PC electrolytic (required for Secret Farter receiver) 1 10µF 16V PC electrolytic 1 1µF 16V PC electrolytic 1 1nF ceramic (.001µF code 102 or 1n0) H 80mm internal width Resistors 3 1MΩ 1 470kΩ 1 330kΩ 2 100kΩ 1 10Ω Car Projects, Volume 2 THE PROJECTS: High-Energy Universal Ignition System; High-Energy Multispark CDI System; Programmable Ignition Timing Module; Digital Speed Alarm & Speedometer; Digital Tachometer With LED Display; Digital Voltmeter (12V or 24V); Blocked Filter Alarm; Simple Mixture Display For Fuel-Injected Cars; Motorbike Alarm; Headlight Reminder; Engine Immobiliser Mk.2; Engine Rev Limiter; 4-Channel UHF Remote Control; LED Lighting For Cars; The Booze Buster Breath Tester; Little Dynamite Subwoofer; Neon Tube Modulator. Mail order prices: Aust – $14.95 (incl. GST); NZ/Asia Pacific – $18.00 via airmail; Rest of World – $21.50 via airmail Or order by phoning (02) 9979 5644 & quoting your credit card number; or fax the details to (02) 9979 6503; or mail your order with cheque or credit card details to Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. siliconchip.com.au Silicon Chip Binders H SILICON CHIP logo printed in gold-coloured lettering on spine & cover H Buy five and get them postage free! Price: $A12.95 plus $A7 per order. Available only in Australia. Silicon Chip Publications PO Box 139 Collaroy Beach 2097 Or fax (02) 9979 6503; or ring (02) 9979 5644 & quote your credit card number. Use this handy form Enclosed is my cheque/money order for $________ or please debit my  Bankcard  Visa    Mastercard Card No: _________________________________ Card Expiry Date ____/____ Signature ________________________ Name ____________________________ Address__________________________ __________________ P/code_______ September 2004  39 Build it now in time for Christmas . . . PICAXE the red-nosed reindeer By Clive Seager This simple novelty project enables you to explore two of the new features of the latest PICAXE micro and have some fun into the bargain. Complete with antlers, flashing eyes and nose, it can play several popular Christmas tunes on command. It can even play mobile phone ring tones! M ICROCHIP HAS recently released a new PIC micro, the PIC12F683, with twice as much memory as the original PIC12F629 used within the PICAXE-08. This has allowed Revolu- tion Education to develop the PICAXE08M, an enhanced PICAXE-08 with in-built music playing capabilities – and much more. The PICAXE-08M supports all of Fig.1: the pinout diagram for the new PICAXE-08M microcontroller. 40  Silicon Chip the standard commands and features of the PICAXE-08, with the following enhancements: • Program memory has been doubled in capacity (approx. 80 lines of code). • Musical tune playing capability, user generated or four pre-programmed tunes (play and tune commands). • 10-bit ADC option on 3 pins (readadc10/readadc commands). • Interrupt feature on inputs (setint command). • Infrared remote control input and output (infrain2/infraout commands). • Continuously driven PWM motor drive output (pwmout command). • Control of radio control type servos (servo command). • Count high frequency pulses within a set time period (count command). • Accurate digital temperature sensor interface (readtemp/readtemp12 commands). • Read serial number from any Dallas 1-wire device (eg, iButton) (readowsn command). siliconchip.com.au Fig.2: with the aid of a PICAXE-08M micro and simple software, the circuit can flash Rudolph’s nose and eyes and play a seasonal tune. The infrared receiver (described next month) allows remote selection of one of four possible tunes. • Software support for increased (8MHz) clock frequency (setfreq command). Note that all existing PICAXE-08 programs will run on the 08M without modification. Playing tunes on a PICAXE The main obstacle when playing tunes on PIC microcontrollers is limited memory space. All the PICAXE chips have a sound command to make noises. However, the number of notes and playback speed, or “tempo”, is very limited, as the sound command data rapidly consumes all available program memory. To overcome these issues, the PICAXE-08M has a newly developed tune command to play music. The tune command incorporates a note data compression algorithm to save memory space. It is also pre-programmed with four melodies: Happy Birthday, Jingle Bells, Silent Night and Rudolph the Red Nosed Reindeer. In addition, it can be programmed with the mobile phone ring tone of your choice. Mobile phone ring tones are widely available on the Internet in “ring tone text transfer” format (RTTTF), as used on most Nokia phones. Although some web sites charge for ring tone downloads, there are still a number of sites that provide these free of charge. A simple microcontroller cannot play complicated “polyphonic” tunes, but siliconchip.com.au can make a good attempt at playing “monophonic” (one note at a time) tunes. Circuit description Fig.2 shows the circuit of our simple Christmas decoration, with the PCB shaped in the form of Rudolph’s head. Output 0 is connected to a 10mm red LED, forming Rudolph’s nose. Output 4 drives two smaller green LEDs for the eyes, whereas a piezo transducer on output 2 plays the tune. Inputs 1 and 3 are connected to a light-dependant resistor (LDR) and push-button switch. In this circuit, the PICAXE-08M micro can be programmed to play a tune when the switch is pressed and/or the light level (sensed by the LDR) changes. Note that the push-button switch circuit is “active low” for compatibility with the infrared upgrade, which will be described next month. The supplied piezo transducer does a reasonable job of tone reproduction. For a richer sound, it can be replaced with a low-cost 40Ω speaker if desired. Wire one of the speaker leads in series with a 10µF electrolytic capacitor before hook-up to the PC board. Kit assembly A kit of parts that includes the preshaped PC board will be available from your usual PICAXE reseller. Fig.3: follow this diagram closely when assembling Rudolph. Note in particular the orientation of the three LEDs and the PICAXE micro as well as the power supply positive and negative leads. The PC board overlay is shown in Fig.3. Assembly of the board is very straightforward, with attention to the points listed below. Although the infrared sensor (IR) September 2004  41 Fig.4: this piano keyboard representation shows the key frequencies in octaves 5, 6 and 7. This is the range of frequencies covered by the PICAXE-08M. and capacitor (C1) appear on the circuit and overlay diagrams, they are required only for remote control operation and can be left out for the moment. Take care with the orientation of the three LEDs, which must have their flat (cathode) sides positioned as shown. Also, make sure that the notched (pin 1) end of the PICAXE micro faces the serial link socket. Before soldering Bit No. 7, 6 – Duration 00 = 1/4 01 = 1/8 10 = 1 11 = 1/2 the battery clip leads, thread them through the adjacent hole to provide strain relief. Power your completed project only from a 3 x alkaline AA cell (4.5V) battery pack or regulated 5V DC supply. Take particular care that you have the power leads around the right way, otherwise you’ll destroy the PICAXE! The following paragraphs explain how the music encoding process Bit No. 5, 4 – Octave Bit No. 3, 2, 1, 0 – Note 00 = Middle Octave (6) 01 = High Octave (7) 10 = Low Octave (5) 11 = not used 0000 = C 0001 = C# 0010 = D 0011 = D# 0100 = E 0101 = F 0110 = F# 0111 = G 1000 = G# 1001 = A 1010 = A# 1011 = B 11xx = P (pause) Notes: 1/16, 1/32 and ‘dotted’ notes are not supported. Only octaves 5-7 are supported. Fig.5: the encoding of each note byte used by the tune command. 42  Silicon Chip works. If you’re not interested in the technicalities and just want to play tunes, you can skip directly to the “Tune Wizard” section below! Tune command The tune command has the following syntax: tune led, speed, (note, note, note . . .) where: (1). led is a variable/constant (0-3) which specifies if other outputs flash at the same time as the tune is being played; ie, 0 = No outputs 1 = Output 0 flashes on and off 2 = Output 4 flashes on and off 3 = Output 0 and 4 flash alternately (2). speed is a variable/constant (1-15) which specifies the tempo of the tune. (3). note, note, etc is the encoded musical note data. Note compression Most ring tones use notes from octaves 5, 6 and 7 (octave 6 starts with “middle C” for the piano players!). A graphical representation of these notes compared to a piano keyboard is shown in Fig.4. There are 12 notes to an octave (including incidental notes), and if you add pause, this gives 13 different possiliconchip.com.au exactly the same length as the number of notes in the tune. Tempo Fig.6: import RTTTL tunes or create your own with the Tune Wizard, included in versions 4.0.1 and later of the PICAXE Programming Editor Speed Beats/Minute 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 812 406 270 203 162 135 116 101 90 81 73 67 62 58 54 Fig.7: this table shows the equivalent tempo in beats/ minute for the 15 possible speed values. sibilities. As the tune plays, each note also varies in duration, and most ring tones use 4 different lengths - notes of duration 1/8 (quaver) 1/4 (crotchet) 1/2 (minim) or 1/1 (semibreve). Theoretically, notes of 1/16 and 1/32 are also possible, but only a few ring tones use these durations and so they are not considered in our algorithm. Considering this information, each note byte can be encoded into just 1 byte of memory as shown in Fig.5. The encoding is optimised to ensure that the most common values (1/4 beat and octave 6) both have a value of 00. Note that as the PICAXE also performs further optimisation on the whole tune, the length of the tune data will not be siliconchip.com.au The speed of music is normally called “tempo”, defined as the number of quarter beats per minute (BPM). The PICAXE tune command allows 15 different speeds (1-15) calculated as follows: The sound duration of a quarter beat within the PICAXE is given by the following formula: sound duration = speed x 65.64ms Each quarter beat is also followed by a silence duration, given by: silence duration = speed x 8.20ms Therefore, the total duration of a quarter beat is: total duration = (speed x 65.64) + (speed x 8.20) ms = speed x 73.84ms The approximate number of beats per minute at different speed values is shown in Fig.7. The chosen values give a good range for most popular tunes. Note that within electronically generated music a note normally plays for 7/8 of the total note time, with silence for 1/8. With the PICAXE-08M the ratio is slightly different (8/9) due to the memory and mathematical limitations of the microcontroller. However, unless you are a gifted musician you probably won’t notice the difference! Tune Wizard The Tune Wizard within the PICAXE Programming Editor software (v4.1.0 or later) allows musical tunes to be created for the PICAXE-08M. Tunes can be entered manually using the drop-down boxes if desired but most users will prefer to import a mobile phone monophonic ring tone. Note that the PICAXE can only play one note at a time (monophonic), and so cannot use multiple note (polyphonic) ring tones. A typical RTTTL ring tone, as downloaded from the Internet, is shown in Fig.8. The first few text characters describe the ring tone name, then the default characteristics (default note duration = 1/4, default octave = 5, bpm Parts List 1 Rudolph PC board 1 miniature LDR 1 miniature piezo transducer 1 miniature pushbutton switch 1 3.5mm stereo socket 1 3 x AA battery holder 1 battery clip 1 8-pin IC socket Semiconductors 1 PICAXE-08M 2 5mm green LEDs (LED1 & LED2) 1 10mm red LED (LED3) Resistors (0.25W 5%) 1 22kΩ (red red orange gold) 2 10kΩ (brown black orange gold) 1 4.7kΩ (yellow violet red gold) 4 330Ω (orange orange brown gold) Note: the infrared receiver (IR) and capacitor (C1) are not required at this stage. Their use will be covered in the infrared upgrade next month. Also required (not in the kit) PICAXE Programming Editor software (v4.1.0 or later) PICAXE download cable (Part No. AXE026) 3 x AA alkaline cells Obtaining kits & software The design copyright for this project is owned by Revolution Education Ltd. Complete kits (Part No. AXE107S) for this project are available from authorised PICAXE distributors – see www.microzed.com. au or 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). Fig.8: Star Wars Theme Tune In RTTTL Format Star Wars Theme: d=4,o=5,b=125:1a#,1f6,8d#6,8d6,8c6,1a#6,2f6,8d#6,8d6, 8c6,1a#6,2f6,8d#6,8d6,8d#6,2c6,8f,8f,8f,2a#,2f6,8d#6,8d6, 8c6,1a#6,2f6,8d#6,8d6,8c6,1a#6,2f6,8d#6,8d6,8d#6,1c6 September 2004  43 Fig.9: Rudolph Program Listing ' ***** main loop ***** main: if pin3 = 0 then playit goto main ' ***** play tune ***** playit: readadc 1,b1 REM debug b1 'read light level 'optional display on screen for testing ' play tune depending on light level if b1 > 200 then play_xmas if b1 > 150 then play_rudolph if b1 > 80 then play_silent play_jingle: play 1,3 goto main 'internal tune Jingle Bells play_silent: play 2,3 goto main 'internal tune Silent Night play_rudolph: play 3,3 goto main 'internal tune Rudolph The Red Nosed Reindeer play_xmas: 'external ring tone tune PICAXE, but will differ slightly due to the different ways that the computer and PICAXE generate and playback sounds. The “outputs” section of the Wizard interface allows you to choose which outputs flash on and off as the tune is played. For the Rudolph project, select both outputs (nose and eyes!) Rudolph program The program listing shown in Fig.9 demonstrates how to play a tune when the switch is pushed. The tune played will vary between four different melodies, depending on the light level falling on the LDR when the switch is pushed. Three of these melodies (Jingle Bells, Silent Night & Rudolph) are pre-programmed tunes included within the PICAXE-08M bootstrap program and are activated by the play command. The final melody (“We Wish You a Merry Christmas”) is a user-defined tune, generated by the Tune Wizard, and played with the tune command. Summary ' We Wish You a Merry Christmas tune 3, 4, ($22,$27,$67,$69,$67,$66,$24,$24,$24,$29,$69, $6B,$69,$67,$26,$22,$22,$2B,$6B,$40,$6B,$69,$27,$24,$22, $24,$29,$26,$E7,$22,$27,$67,$69,$67,$66,$24,$24,$24,$29, $69,$6B,$69,$67,$26,$22,$22,$2B,$6B,$40,$6B,$69,$27,$24, $22,$24,$29,$26,$A7,$22,$27,$27,$27,$E6,$26,$27,$26,$24, $E2,$29,$2B,$69,$69,$67,$67,$02,$22,$22,$24,$29,$26,$E7) goto main The play and tune commands allow you to play simple musical tunes on the new PICAXE-08M. There are approximately 1000 tunes for free download on the software page of the PICAXE website at: www.picaxe.co.uk Some other possible sources for free ring tones are: www.ringtonerfest.com www.free-ringtones.eu.com www.tones4free.com Next month = 125), then each note in turn. This ring tone can be imported straight into the Tune Wizard. The Tune Wizard will then automatically generate the BASIC code required for the PICAXE program. 44  Silicon Chip The tune can also be tested on the computer by clicking the “Play” menu (assuming the PC is fitted with a soundcard and speakers). The tune played will give you a rough idea of how the tune will sound on the Next month, we’ll show you how to control Rudolph via an infrared remote control. The transmitter also uses a PICAXE-08M chip and will take you less than five minutes to assemble. In addition you have to install two parts on the PC board and change the SC PICAXE program. siliconchip.com.au SEPTEMBER SALE 1 Super High Capacity Ni-MH Batteries Our largest capacity yet, AAA 900mAh Nipple Cap SB-1723 1+ $3.59 10+ $3.15 20+ $2.75 Solder Tags SB-1724 1+ $3.78 10+ $3.30 20+ $2.95 10+ $1.45ea 1.3 Mega Pixel Mini Digital Camera Great photos anywhere! Take it with you anywhere, anytime! It operates as a digital camera on its own, or a streaming web cam when connected to a PC. It gives you great 1280 x 960 pixel images, and measures just 86 x 31 x 27mm. Cat. QC-3226 $ .00 AA 2300mAh Nipple Cap SB-1725 1+ $5.50 10+ $4.90 20+ $4.30 Solder Tags SB-1726 1+ $6.25 10+ $5.50 20+ $4.95 2004 CATALOGUES Our 424 page printed & CD-ROM catalogues are still available! GET YOUR COPY NOW! 424 Page Printed Catalogue - $3.95 CD-ROM Catalogue only $3.00 59 OUT NOW HDTV Distribution Amp Now you don’t need multiple set-top boxes! Now you can have top quality TV in more than one room. This unit distributes HDTV signals up to four ways without Cat. AC-1678 .00 losing signal quality. Powered from the $ supplied mains plugpack. 299 40Ch UHF CB Transceiver Wrist Watches A true CB transceiver in a wrist watch! They are great just for fun or serious activities, and eliminate a bulky transceiver unit hanging off your belt. They operate on the Citizen Band (CB) frequencies with a range of up to 2km. They are powered from internally Cat. DC-1070 rechargeable Li-Ion batteries. Pair Supplied as a pair complete with mains $ charger. See website for details. 199 NEW STORE IN DARWIN 297 Bagot Rd. Coconut Grove. NT. 0810 OPENS LATE SEPTEMBER 20 LED MR-16 Lamps Avoid the high running cost of Halogens! LED type MR-16 lamps operate with lower heat and far less power consumption compared with their Halogen counterparts. They can directly replace existing MR-16 Halogens. Power consumption 1.5 2W. Comparable light output to a 15W halogen globe for white, slightly less for colours. .95 White Cat. ZD-0320 $ .95 Blue Cat. ZD-0321 $ $ .95 Green Cat. ZD-0322 Red Cat. ZD-0323 $ .95 Yellow Cat. ZD-0324 $ .95 29 24 24 19 19 18 0 0 0 2 2 8 8 8 Freecall For Orders MASSIVE 2,300mAh KIT OF THE MONTH Dr Video Kit MkII An even better video stabiliser! Ref: Silicon Chip June 2004. 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, including Macrovision, by connecting our Doctor Video Kit inline with your DVD player or VCR. Kit supports S-Video and composite video signals. Case, circuit board, electronic Cat. KC-5390 components and comprehensive $ .95 assembly instructions are supplied. 99 KIT OF THE MONTH USB Phone Charger / Mini Massager 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. 39 UB1 Jiffy Box BARGAIN! What a stuff up! Our supplier sent us these grey UB1 (158 x 95 x 53mm) project boxes by mistake! Quantities are strictly limited, grab them now before they’re gone! Cat. HB-6021 $ .00 2 Cat. GG-2268 $ .95 12 Animated Pen Stand TED! R-RA ALMOST HALF THE PRICE OF THE BLACK VERSION Sound Absorbing Material BARGAIN! Keep the noise out! This damping material is similar to our previous material AX-3682, but a little under spec. You can get it at a great price, but stocks are very limited, so grab it now or you will miss out! Two types available: 330(W) x 640(L) x 5.5mm 330(W) x 680(L) x 4.0mm Cat AX-3685 Cat AX-3686 $11.95 $9.95 HSS Step Drill Bits - 1mm steps Drill multiple size holes with the one bit! Suitable for plastics and un-hardened metals (such as aluminium or copper sheeting etc) up to 4mm thick! Made from high speed stainless steel (HSS). Two sizes available: 4 - 12mm Cat. TD-2436 12 - 20mm Cat. TD-2438 Cat. TD-2436 Cat. TD-2438 $ .95 $ .95 19 Your Grandmother won't like it, but you will! It lets out a series of amusing sounds and lifts its head when you insert a pen into the rear-facing rectal receptacle. Cat. GT-3110 $ .95 19 Bed Wetting Alert Kit Dry nights - happy kids! Ref: Silicon Chip Sept ‘04. The bed wetting alert uses the wireless transmitter from our witty Remote Controlled Fart Gadget to sound an alarm when the modified transmitter detects any moisture. It works very well, and can help train your child to wake up before they wet the bed, so they can go to the toilet instead. Kit supplied with fart gadget Cat. KC-5396 for modification, PCB, and all $ .95 electronic components. September 2004 Verbatim High Performance CD-R A brand you can trust. Super “Azo” technology ensures quality, reliability & compatibility. 70 min, 800MB, up to 50 speed. Cat. XC-4707 BUY IN BULK $ .65 29 Vari-Focal Dome Cameras Superior flexibility! Fitted with Auto-Iris Vari-Focal lenses, these cameras will suit a wide range of surveillance conditions, light sources, and more. They feature selectable backlighting compensation that adjusts according to light conditions. B&W 380 TV Lines Cat. QC-3295 $ .00 279 Colour 480 TV Lines Cat. QC-3296 $ .00 369 1000 Foot Air Rocket and Launcher Set 12VDC Cooler / Warmers Keep your pies hot, or your beers cold! A solid state thermoelectric device cools to -25°C, or heats to +65°C relative to ambient temperature. They are a reliable and portable way to transport hot or cold food and drinks over long distances without trouble. They are powered from your car’s cigarette lighter socket or a mains plugpack. Three models available: 4 Litre Red 4 Litre Silver 8 Litre Red Cat. GH-1376 44.95 $ The sky is the limit! This air powered launcher uses a compressed air based propulsion system to launch the rockets high in the sky. It uses any heavy duty foot pump, or a 12V car pump which is (not included but commonly available). Limited qty. Was $59.95 Buy a spare pack of Rockets and 60 Bursting Discs for just $19.95 Save $3.95! 4L Holds 6 x 375mL Cans Cat. GT-3000 Cat. GH-1377 44.95 $ Cat. GH-1378 89.95 $ SAVE $20 39.95 $ Wind Up Dynamo LED Torch 8L Holds 12 x 375mL Cans Superbright Torches with 1W Luxeon LEDs Luxeon brand LEDs are some of the brightest in the world. Not only are they the brightest, they are also the whitest! Pure, clear, white light, in a neat and compact package. The light output from these torches is astonishing. See our website for full details. 1 Watt Luxeon Head Torch Super lightweight, adjustable angle, and head strap. A great backup torch! Wind the handle for about a minute, and you get about 30 minutes of superbright light. Selectable 1 or 3 LED operation, water resistant. Cat. ST-3337 29.95 $ 69.95 $ Black aluminium finish, wrist strap included. 59.95 $ Superbright 3W Luxeon LED Torch Super bright, super white! Superior light output from a powerful Luxeon LED. It has a lens to focus or broaden the beam, strong aluminium body, and wrist strap included. Cat. ST-3334 89.95 $ 40 Channel UHF CB Band Transceiver Short range communication without mobile phones! Keep in touch within 1km in the city, or 5km in an open area. Operating on standard 40 channel CB frequencies, they can be used with CB repeaters throughout Australia. Accessories available, see website for details. Cat. DC-1010 49.00 $ OR 2 FOR $85 No batteries required! Just shake them up and down, and the mechanism produces a current, charges the internal battery, and powers the LED. If the torch dims, shake it again. Two sizes available: Small - 165 x 38(dia)mm ST-3340 Large - 235 x 40(dia)mm ST-3342 Cat. ST-3340 14.95 $ Motorised Tie and Belt Rack Handy storage with a twist! It holds up to 64 ties, and 8 belts. With the flick of a switch, it will rotate them around like they are in their own fashion show, making the morning’s selection easy. Requires 4 x C batteries. Cat. GH-1405 29.95 $ Remote Controlled Flying Saucer Soar to new heights of excitement! This untethered flying saucer will soar into the air, while you maintain full control over its height. A small internal battery can be recharged on the landing base. Saucer dia. is 230mm. 49.95 Faraday Hand Powered LED Torches Cat. ST-3333 39.95 $ $ 14 1 Watt Luxeon Hand Torch Cat. YS-5527 Cat. GT-3004 Faraday Hand Powered Calculator No flat batteries ever! Shake the unit side to side to charge its internal battery. If it goes flat, Cat. QM-7275 just shake it again. $ .95 Cat. ST-3321 Electronic Corkscrew Simple cork removal! Rechargeable batteries power the unit with an active charging stand supplied. Great if you have trouble manually removing corks. Stands 28cm high. Dynamo Powered AM/FM Radio with LED Torch Just wind the handle for power. Use this as an emergency radio when there is a risk of natural disasters or power failures. You can listen for updates when there is no power, or just save by not using batteries. Cat. AR-1775 Water resistant case, optional $ .95 battery and plugpack power. 34 3 in 1 UV/Laser/Torch Keyring A very versatile keyring attachment! It operates as a great laser pointer, a UV LED torch, and a superbright white LED torch. Cat. ST-3342 Cat. ST-3104 24.95 $ 40 Channel UHF CB with CTCSS Selective Calling Eliminate general CB traffic noise! CTCSS keeps your transceiver in mute mode until it receives a call tone from another CTCSS equipped transceiver operating on the same sub-channel. Up to 1km city, and 5km open field range. Accessories available, and details on Cat. DC-1030 CTCSS are on our website. $ .95 79 See instore for a great deal on rechargeable batteries & chargers for these units!! 19.95 $ High Power 40 Channel UHF CB Band Transceiver Long range, great performance! If you need more range than what our standard models can offer, try this one. It’s our high powered model that boasts 1.5 watts, so you can communicate up to 8km. It can also operate in a limited power mode to conserve battery power. Eliminate short distance mobile calls, and these units will pay for themselves Cat. DC-1040 many times over. 119.00 $ 10% to 90% OFF CLEARANCE ITEMS Check out our desparation sale published in this months Silicon Chip magazine. Fast Charger / Battery Combo Cat. MB-3532 24 $ .95 Cat. TH-1906 SAVE $5 Power your digital camera from rechargeable lithium ion (Li-Ion) batteries and save! Lithium camera batteries are expensive and wasteful. Use rechargeable batteries and you will still be using them long after they have started saving you Product may differ money. The chargers are from picture. powered from a mains plugpack or 12VDC cigarette lighter socket, and have LED charging indication. One battery is included, see below for extra batteries. CR-V3 Li-Ion Charger 59 $ .95 .95 Rechargeable Lithium Ion Digital Camera Batteries High quality Lithium Ion batteries for use in digital cameras and equipment. CR-V3 CR123A 3.6VDC 1500mAh capacity. 3.6VDC 600mAh capacity. 29 19 $ $ .95 .95 Alcohol Breath Tester with Readout Drink Responsibly! Dring driving is dangerous, and a crime. Keep an eye on your blood alcohol level. An LED scale displays your blood alcohol level between 0.00% and 0.1%. The QM-7292 offers a good indication of blood alcohol, but should not be relied upon for precise results. Drink responsibly, and never drink and drive. 16 in 1 Stainless Steel Multi Tool Rugged and versatile! Wire cutters, file, saw, scissors, bottle opener, can opener, knives, screwdrivers, and more! Was $29.95 Cat. TH-1903 24.95 $ Hot coffee all trip long! Four temperature settings between 29°C and 71°C allow you to set the ideal temperature to keep your drink at. Requires 12VDC. Cat. QM-7292 59.95 $ 24.95 39.95 $ 18 0 0 0 2 2 8 8 8 Freecall For Orders Cat. XC-0268 49.95 $ Fishing Tool Set Cat. GT-3275 9.95 $ Cat. GH-1354 24.95 $ Gives a whole new meaning to "Touch Me There"! Wear this badge and you are sure to be the centre of attention as everyone tries to push your buttons. Cat. GT-3315 9.95 A must have for every recreational fisherman! It includes a 14 in 1 multi tool, 0 - 6kg scales, and an LED hand torch, all in a convenient belt pouch. Cat. TD-2053 29.95 $ Desk Clock with Alarm and Calendar Small, sleek, and stylish. A unique rubber stand moulds to any shape to suit all surfaces. Clock face size is 81(H) x 55(W)mm. Cat. XC-0216 17.95 $ $ Novelty Keychain with Orgasm Sounds Everyone will want what you're having! Keep this little beauty in your pocket or purse. It lets out orgasmic sounds at the press of a button. What a laugh! Accessories not included 29.95 $ Move over James Bond! A clock, stopwatch, thermometer, and compass all in one! Calendar and alarm functions also included. Cat. GH-1302 Perfect water temperature, every time! Prevent scalding from hot water, and ensure the correct temperature. It displays the actual water temperature coming through the shower head. Selection of narrow and wide stream, or off. Cat. XC-0265 Digital Multifunction Sports Watch Novelty Badge with Orgasm Sounds A hygienic bathroom solution! Ultraviolet rays sterilize your toothbrushes and razors etc, to stop the build up of potentially harmful bacteria. It helps remove odours, and can hold up to 4 toothbrushes and 1 razor at once. $ Talking Pedometer with FM Radio SAVE $5 Be the master of the turntable! Well, not exactly, but at least have some fun. It plays one of three tunes, and you turn the disc for a ‘scratch’ effect creating your own musical masterpiece. •Measures approx. 75 x 65mm. A great aid en for draftsm too! Step into health and fitness! It announces the steps, distance, calories burnt and exercise time when you press the TALK button, or automatically at intervals. Integrated auto-scan FM radio with earphones included. Heated Travel Mug with Temp Display Antibacterial Toothbrush Holder Cat. GH-1507 19.95 $ Shower Head with Temperature Display Cat. SB-1742 Cat. SB-1740 Cat. XC-0375 Novelty DJ Scratch Effects Box Cat. MB-3584 44 $ SAVE $5 9.95 $ Rechargeable Lithium Ion Digital Camera Battery Chargers Cat. MB-3582 How far is the next turn off? Automatically convert a map’s 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. Handy helper! It has pliers with wire cutter, a saw, a bottle opener, a Phillips and flat screwdriver and a knife. Was $14.95 Save $9.80 of individual pa f rts prices! CR123A Li-Ion Charger Digital Map Distance Calculator 5 in 1 Multi Tool A cheap rechargeable starter! Includes a mains charger and 4 x AA 1650mAh Ni-MH batteries. LED charging indication. Was $29.95 Cat. GT-3325 9 $ .95 Alarm Clock with Laser Time Projection Projects the time on your wall or ceiling! It includes an LCD for constant display, and projects the time when you touch the button or the alarm goes off. Cat. XC-0218 39.95 $ USB Wireless Security Lock Simple PC security! Here is a neat and easy way to protect your PC from prying eyes and intrusive fingers. You keep a small transmitter with you, and when you are out of range (around 2m) it puts your PC into ‘lock mode’. When you return, it returns to Cat. XC-4842 .95 normal operation. Transmitter, receiver, $ software and drivers supplied. 69 Automotive / Aircraft 60 Watt Laptop Power Supply A versatile power adaptor! Not only can you run a laptop from your car cigarette lighter, many modern airliners are also fitted with 12 volt power outlets. It comes with 12 adaptor plugs that adjust the output voltage to suit the particular laptop in use. Cat. MP-3468 $ .95 129 Automotive Laptop Power Supply Wireless Network Adaptors A range of cards to suit all computers and provisions. Common specifications: Cat. YN-8066 •IEEE 802.11g wireless network compatible. •Interoperation with IEEE 802.11b 11Mbps networks. Cat. YN-8067 •64 / 128 Bit WEP encryption. •54Mbps high speed transfer rate. •40 - 100m indoor range. •100 - 300m outdoor range. •Low power consumption. •Plug and Play compatible. Cat. YN-8068 •Compatible with ALL TYPES Win98/SE/2000/ME/XP $ .95 each PCI Wireless Network Adaptor Cat. YN-8066 USB 2.0 Wireless Network Adaptor Cat. YN-8067 PCMCIA Wireless Network Adaptor Cat. YN-8068 Wireless Access Point with 4 Port Router Cat. MP-3466 $ .00 119 USB Pan / Tilt PC Camera with Remote Access This is one of the most useful PC based cameras we have seen! The first thing you will notice is that it's a webcam. It captures video at 640 x 480 resolution, at a frame rate of up to 30fps. What you cannot tell just by looking at it however, is that it has full Cat. QC-3395 functionality as a pan/tilt $ .00 camera, with motion controlled via the serial port! You can log onto a preset IP address, and actually take control of the pan/tilt functions. Software and drivers are supplied on CD-ROM, and it is compatible with Windows 98/SE, ME, 2000, and XP. •640 x 480 pixel resolution. •Colour CMOS sensor. •111(L) x 97(W) x 86(H)mm approx. 399 Brushed Aluminium 64 CD Case Allows communication with up to four wireless network computers. It includes support for WAN, web based and remote management, auto detection and configuration of ISP, built in firewall, and more! See website for details. •IEEE 802.11g and IEEE 802.11b compatible. •Up to 54Mbps data rate. Cat. YN-8086 $ .00 •Static and dynamic routing. •VPN pass through. 179 you download your photos! Why use another mains outlet when you can utilise the USB power at hand. Charge up to 4 x AA x AAA, Ni-MH or Ni-Cd batteries. Cat. XC-4950 $ .95 19 128MB 5 in 1 Digital Camera Possibly the most versatile digital device around! It measures just 72 x 17 x 15mm, but what you can’t tell by looking at it, is that it actually has five different functions. It operates as a: •300k pixel digital camera storing up to 2000 images. •100k pixel digital video camera with up to 20 mins storage. •Voice recorder with up to 2 hrs storage. SAVE •Web camera when connected to a PC. $40 •128MB USB flash disk for data storage. Powered by an internal lithium battery Cat. QC-3224 charged by the USB port. $ .00 Was $299 259 12 in 1 USB 2.0 Card Reader Super fast data retrieval from your favourite media! Supports most common media cards including XD. Cat. XC-4853 $ .95 59 XPERT DVD Maker Convert all your old VHS tapes and Media Card & Socket Cleaning Kits camcorder cassettes to DVD! The clarity and longevity Help eliminate read and of DVD can now be write errors. given to your old home These kits include a memory movies and videos. Now card socket cleaner, special there is no need to micro particle sandpaper, have thousands of high tech cleaning cloths, megabytes handy, cleaning solution and 12 cleaning swabs, designed to remove dirt Accessories just so you can import and finger prints. Includes adhesive film not included your movies. XPERT DVD Maker does it on the fly! Just install the card, to protect the LCD on your camera too. connect your VCR or camcorder, and off you go! You Kit for Compact Flash Cat. XC-4900 ALL TYPES do of course still need to have a CD/DVD burner, but Kit for MMC / SD Cat. XC-4902 $ .95 ea prices are falling rapidly, and they are now very Kit for Smart Media Cat. XC-4904 affordable. Supports full resolution PAL (720 x 576 <at> 25fps) with composite and S-Video Cat. XC-4811 $ .00 inputs. See website for details. USB 2.0 Video Capture Box 9 Strong and stylish! Finished in brushed aluminium, it protects your CDs as well Cat. AR-1497 CDs not as looking $ .95 included great. 19 USB Massage Ball SAVE $10 Jaycar now carries a range of wireless networking devices to get you connected without wires. It is becoming increasingly common for homes and even offices to be networked without wires, and it is now very affordable. 89 Includes plug for Dell laptops! Power your laptop on the go from a 11 - 16VDC source. It can provide 15, 16, 18, 19, 20VDC <at> 6A, or 22, 24VDC <at> 5A. Lightweight switchmode design, 6 plugs included. Relax on the computer! Give yourself a quick massage while on the computer and relax! Was $24.95 Powered Battery Charger The Wireless Network Revolution! USB Recharge your batteries while Cat. GG-2265 $ .95 14 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 MPEG 2. 149 DVD+R Spindles Great value! DVD+R 10 Pack , 8 Speed Spindle DVD+R 25 Pack , 4 Speed Spindle Cat. QV-3090 $ .00 99 Cat. XC-4736 Cat. XC-4737 Cat. XC-4736 $ .95 29 Cat. XC-4737 $ .50 29 www.jaycar.com.au Online Internet Ordering Remote Control A/V Selectors No more source switching hassles! Say goodbye to connecting and reconnecting cables because you have run out of AV inputs on your home theatre system. This device allows connection of up to 3 inputs that can be switched using the remote control, so you don’t even need to get out of your chair! Composite/Audio/TOSLINK/ S-Video Version Cat. AC-1674 Cat. AC-1674 $ .95 RGB/Audio/TOSLINK/ S-Video Version Cat. AC-1676 Cat. AC-1676 $ .00 148 149 RF Modulator with 4 A/V Inputs Long distance cable runs with less degradation! Converts the composite or S-Video inputs into an RF signal for transmission to any wired room in the house, so you can share DVD, VCR signals etc everywhere. Four selectable inputs. Cat. AC-1690 $ .95 99 2.4GHz Portable Video Baby Monitor / Wireless Monitor System Keep more than an ear out for your sleeping baby. Why not keep an eye on them as well? An integrated 45mm LCD allows you to see and hear your child. Camera features 6 IR LEDs for ‘night vision’, so you don’t even need a light on. The applications for this system don’t stop there however; you could use it for any remote monitoring application! Up to 3 cameras can be used with the receiver. See below for extra cameras. Enjoy the surround sound experience. 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. They sound GREAT! Cat. CS-2465 SAVE $ .95 Was $99.95 99 Split signal without loss! Share a live feed from a camera between a monitor and recorder etc and don’t worry about any signal loss. Requires 12VDC or 24VAC power. Cat. QC-3435 $ .95 3 Way Weather Resistant Speakers Expand your Hi Fi to the outdoors! Mount them under the eaves or protected walls. They won’t mind a little moisture, and Cat. CS-2432 $ .95 they sound great! 49 89 Video Signal Amplifiers Gold Speaker Cabinet Stands Just a little boost! Ideal for a range of transmission and surveillance applications, they feature on-board brightness and contrast controls to help ensure picture quality. Housed in an ABS enclosure, they have an integrated mounting flange, and require 12VDC power. Single Channel Output Cat. QC-3437 Dual Channel Output Cat. QC-3438 Reduce speaker resonance! Lift speaker cabinets off the Cat. HS-8000 $ .95 floor. Pack of four. Two packs required for SAVE a pair of speakers. $7 Was $31.95 24 30WRMS 6.5" Home Unit Subwoofer 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. Cat. AA-0512 Mains powered, great $ .00 sounding bass. Cat. QC-3438 $ .95 79 B&W Video Doorphone Cat. QC-3280 $ .00 299 See who’s at the front door! Make sure you don’t open the door to an intruder. Check who is knocking from behind closed doors. Supplied with all hardware and wiring. SAVE Was $199 $20 149 High Definition Digital Terrestrial TV Card for PCs Cat. QC-3602 $ .00 179 Colour Video Doorphone Even better vision! This is the colour version of the model above. It has a 4" LCD for viewing, so you have an even better picture of who is there. Features include a panic button, electric door strike control, and more. Supplied with all hardware and wiring. Was $399 189 SAVE $40 Is this the simplest way to setup surveillance? This USB receiver is compatible with the wireless cameras above. You can capture and view the signals with the composite video output for a TV, and it has an integrated USB output for connection to a PC. You can use up to 3 cameras at once, while the software supports motion sensing, remote access, Cat. AR-1835 scheduled recording, and much more. $ .00 See website for details. 249 Portable viewing pleasure. This monitor delivers high resolution pictures with clear sound reproduction through its internal speaker. Powered directly from 12VDC, it can be used in a car, or powered from a mains plugpack. See SAVE website for details. $40 Was $399 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 ratios. Was $199 SAVE $20 Cat. XC-4819 $ .00 179 USB Radio and Remote Control Cat. QC-3606 $ .00 359 7" TFT LCD Widescreen Monitor 2.4GHz Wireless A/V USB Receiver 69 $30 Two Output Video Splitter 69 These are the cameras that are used in the Baby Monitor (above) and USB receiver below. They really do simplify surveillance system setup. They feature IR LEDs for ‘night vision’, audio, and measure just 110 x 65 x 55mm. Cat. QC-3281 $ .00 18 0 0 0 2 2 8 8 8 As used in the Beach Boys’ classic hit Good Vibrations! The Theremin has an amazing range of notes from piercing shrieks to low-end growling sounds. Music shops sell Theremins for several hundred dollars, so you will save a bundle with Jaycar! Cat. AM-4025 $ .00 •Requires 9-12VDC. Cat. QC-3437 $ .95 2.4GHz Wireless Camera to Suit AR-1835 Freecall For Orders Theremin Synthesiser Pre-Built and Tested 3 Piece Surround Sound Add-On Radio on your PC! Receive, play, and record FM radio stations through an ultrastable phase-lockedloop (PLL) tuning system for superior reception. Includes an IR remote control which can also be used with software such Cat. XC-4880 as MS PowerPoint. SAVE $ .95 Was $79.95 69 $10 Indoor TV Antenna with Signal Booster Cat. QM-3752 $ .00 359 Improve TV reception! If you are just using standard ‘rabbit ears’, try this. You will be amazed at the difference! SAVE Was $64.95 $10 Cat. LT-3135 $ .95 54 12VDC 19 LED Stop/Tail Light Safety first! A typical stop/tail lamp takes between 120-160 milliseconds to fully illuminate. This translates to over 4 metres at 100km/h. An LED stop/tail lamp illuminates instantly. The extra 4 metres may be the difference between a crash and a near miss. Yellow Bayonet Lamp Cat. ZD-0317 $ .95 SIMPLICITY IS THE KEY! Sometimes you only need a go / no go indication, and complex equipment just isn’t necessary. These units are cheap, simple, and very effective. Cat. ZD-0316 $ .95 14 14 also available Non Slip Car Mat 5 Stereo FM Modulator No inputs? No worries! Just connect your RCAs into this unit, and it converts the signal to a tuneable FM band. It includes an antenna connection for Cat. QM-3780 crystal clear $ .95 reception. 5 Retro style relief! Keep an eye on your line level audio signals and battery voltage with this retro styled analogue meter. Standard 1U DIN Cat. QP-5035 mounting. $ .95 Was $89.95 Cat. QP-2284 $ .95 8 SAVE $20 Safe and easy voltage detection. When positive voltage is detected, it will buzz, vibrate, and light up. It is safe to use with ECUs, air bags, sensors, and transducers etc Cat. QP-2212 $ .95 29 Digital Voltage & Current Terminal Block Stud / Metal / Voltage Tester Locate studs with ease! This unit will find studs behind walls, flooring, and ply up to 3/4" thick. Also detects voltage and metal. Cat. QP-5550 $ .95 49 Precision Mini Metal Lathe Deal Industrial quality on a budget! This fantastic unit has a FULL cast iron bed, frame, and headstock assembly, just like industrial lathes. It bristles with safety features including a plastic chuck cover which must be down for the machine to operate. This prevents you from starting the lathe with the chuck-key in! We have not seen a product of this quality, at this price. See website for details. The cutting tools, drill chuck, and live centre and all usually sold extra, costing $107.80 over $100 more, but are worth of pa rts included in Cat. TL-4000 already $ .00 the price! included! Cat. QP-2282 $ .95 29 Beats wearing out your finger! Just slide the gun over the tie, and pull the trigger! It tensions and cuts off the excess all in one action. Was $19.95 14 28 24 A quality portable iron! Make roadside electrical repairs, or just avoid running mains extension leads when doing automotive work! 2.5mm lead with cigarette lighter plug. Cat. TS-1530 $ .95 14 Keep your tips in top condition! It contains solder and flux powder to clean and tin in a single quick action. Cat. TS-1512 $ .50 •15 gram tin. 6 Thermoelectric (Peltier) Modules Solid state heating & cooling. These reliable thermoelectric devices cool to -27°C and heat to +64°C relative to ambient temperature. They require 12 - 15VDC, heatsinks, and fans depending on the application. 33 Watt 4 Amp Cat. ZP-9100 54 Watt 6 Amp Cat. ZP-9102 68 Watt 8 Amp Cat. ZP-9104 $11.95 $14.95 $17.95 Blade Fuses with Blown Indication Cable Tie Gun Cat. TH-2600 $ .95 Versatile LCDs! A compact, 2 line / 16 character LCD with a total of 196 ASCII, special, and custom characters. Display size 64 x 16mm. See website for details. Standard LCD QP-5515 Cat. QP-5515 Cat. QP-5516 $ .95 .50 Backlit LCD QP-5516 $ Soldering Iron Tip Cleaner / Conditioner 3 - 28V Wireless Auto Tester 69 19 12VDC 60W Soldering Iron Locate studs quickly and easily! Simply hold down the button and slide along the wall. An LED illuminates when a stud is detected. In-Dash Audio Level and Voltage Meter 899 Cat. QP-2264 $ .95 Mini Keyring Stud Finder 89 Cat. TD-2022 $ .95 Dot Matrix LCD Modules Neon Spark Plug Tester Simple tester for a simple problem. Don’t get caught with a faulty spark plug. Bright neon illumination indicates spark presence. GS and VDE tested and approved. Soft rubber grip handles, with insulation right to the tip. CHECK THE GREAT PRICE! A quick go / no go indication. Great for simply testing to see if a wire is live. High quality insulated probes, neon indication. Cat. QP-2240 $ .95 3 Stop sliding on your dash! Keep your sunglasses, phone, coins etc where you left them. pack of 2. Cat. GG-2250 Accessories $ .95 not included Measures up to 200A! Keep check on high power 12VDC voltage and current. 4 gauge input and output terminals. Measures 130(L) x 78(W) x 37(H)mm. 90 - 300VAC / DC Voltage Tester 1000V 7 Piece Screwdriver Set SAVE $5 23Pc Ratchet & Bit Set A well selected set of tools. A strong metal case keeps them all together, and is durable to prevent damage. A must for every toolbox. Cat. TD-2029 $ .95 29 Quickly locate blown fuses! An internal lamp illuminates as soon as the fuse blows, so there is no need to test them with a meter. They work with voltages up to 32VDC, so they are suitable for almost all automotive applications. Type Colour Blade Fuses Mini Blade Fuses 3A Pink Cat. SF-5000 Cat. SF-5050 5A Orange Cat. SF-5002 Cat. SF-5052 7.5A Brown Cat. SF-5004 Cat. SF-5054 10A Red Cat. SF-5006 Cat. SF-5056 15A Blue Cat. SF-5008 Cat. SF-5058 20A Yellow Cat. SF-5010 Cat. SF-5060 25A Clear Cat. SF-5012 Cat. SF-5062 30A Green Cat. SF-5014 Cat. SF-5064 Blades (ea) Mini Blades (ea) $ .00 $ .25 1 1 10% to 90% OFF CLEARANCE ITEMS Check out our desparation sale published in this months Silicon Chip magazine. NEW HARDCORE ELECTRONICS! TDA1905 5W Audio Amp IC BARGAIN Magtrix Magnetic Connectors Need to be seen to be believed! Extremely versatile and provide a unique Battery for demonstration and reliable electrical purposes only connection that can disconnect and reconnect without fuss. Ideal for a myriad of projects where Cat. PP-0050 connecting and disconnecting power can $ .95 be a problem. Reverse polarity conscious, sold as a pack of 3 matching pairs. 4 Carbon Monoxide Meter Protect from the hazards of CO. Carbon monoxide is a silent killer that can be generated by any household appliance running on gas or kerosene or heating oil and internal combustion engines. This meter detects concentrations as low as 1ppm Cat. QM-1665 $ .00 up to 1000ppm with a 5% accuracy. 229 Remote Location Data Logger Log periodical temperature measurements unassisted for up to one year in the field. An internal lithium battery provides power, while an IP-67 rated enclosure protects from the elements. Logging rate can be set between every 10 seconds to every 12 hours. Cat. QP-6012 Data is retrieved with a PC $ .00 using the internal USB port. 149 Dual Output Tracking Lab Power Supply Effectively two power supplies in one! This versatile lab supply offers 0 – 40VDC at up to 3A from each output. LCD readout for voltage and current on both outputs. MP-3092 SAVE Cat. Was $479 $ .00 $70 409 Audio Frequency Generator 249 PROTEK 20MHz Dual Trace CRO Professional design, great functionality. Housed in a steel pressed cabinet, a comprehensive control panel gives you superior control, while a large 6" screen with zero parallax graticule ensures great display and reading accuracy. Supplied with two sets of probes. Was $698 SAVE $100 18 0 0 0 2 2 8 8 8 Freecall For Orders SCOOP PURCHASE! It is a 5W audio amplifier with an internal muting facility. 16 DIP package, data sheets are available on our website and are included with the 100 pack. Cat. ZL-3602 Cat. ZL-3600 $ .50 pk 10 $ .95 ea 34 3 1W Luxeon Brand LEDs Up to 120 Lumens per LED! They have a 100,000 hour LED life expectancy, are fully dimmable with excellent ESD protection. Cat. ZL-3604 200 pk 100 $ SMD Vacuum Pick-Up Tool The only way to handle SMD components! Tweezers are clumsy. This device lets you latch on to the top of the device without harm. Cat. TH-1974 Especially handy for PLCC devices. $ .95 59 Blue 7 Segment LED Display Cool blue single digit. Common cathode, 50mCd typical. See our website for data sheets. Cat. ZD-1856 $ .95 Red Orange Green Blue White Cat. ZD-0400 Cat. ZD-0401 Cat. ZD-0402 Cat. ZD-0403 Cat. ZD-0404 Economy Brand 1W LEDs Cost effective alternative! We believe our in-house brand economy LEDs are just as bright as the Luxeon counterparts at a much cheaper price. See website for data. Red Cat. ZD-0410 $10.95 Green Cat. ZD-0412 $12.95 Blue Cat. ZD-0414 $12.95 White Cat. ZD-0416 $12.95 1.5V to 30VDC 1A Switchmode Lab Power Supply 5 GPO Mains and Earth Leakage Tester Make GPO installation and checking a breeze! Identifies problems with wiring, and checks earth leakage circuit breakers using selectable trip current. A must have for electricians and Cat. QP-2000 $ .95 handymen. 19 Revolutionary variable switchmode design! These units are stackable to provide a multi-rail power supply configuration. Over voltage, over current, and short circuit protection is included, so you have a reliable, safe lab power source. Cat. MP-3095 $ .00 Temperature measurements without touch! Infrared technology takes accurate measurements of surface temperatures. Includes laser target guide. Was $99.95 Cat. QM-7224 SAVE $ .95 89 palm of your hand! Features include a high contrast LCD with wide viewing angle, full automatic setup, true RMS, and sound level measurement, all for the cost of a good multimeter! Cat. QC-1916 SAVE $ .00 Was $349 $50 299 Super Torque Driver Ratchet Cat. QC-1908 $ .00 598 Comfortable driving! It accepts standard driver bits, adjustable and lockable head angle, with a rubber grip handle. Cat. TD-2033 $ .95 Was $13.95 SAVE $4 199 Digital Vernier Caliper Mini Non-Contact Thermometer $10 $14.95 $14.95 $16.95 $16.95 $16.95 No eye strain taking readings! The clear LCD shows the measurement in millimetres or inches. Accurate to 0.01mm. Was $79.95 Cat. TD-2082 $ .95 SAVE $10 69 10MHz Velleman Handheld Oscilloscope 3.6V Rechargeable Cordless Lab level testing in the Screwdriver Huge range, great price! Output can be varied from 10Hz to 1MHz in a sine or square waveform. Synchronising input terminal. Cat. QT-2300 SAVE $ .00 Was $319 $70 This section is dedicated to what’s-new for the Hardcore Enthusiast. 9 Take the strain out of your wrists. Use our powered screwdriver and install or remove multiple screws with ease. Was $19.95 Cat. TD-2495 SAVE $ .95 $5 14 Automotive Battery and Alternator Tester Keep an eye on your car battery! This tester will check battery condition, and that your alternator is charging properly. Was $13.50 Cat. QP-2262 SAVE $ .50 $4 9 Video Enhancer and Y/C Separator Kit Convert composite video to S-Video and enhance it! Ref: Silicon Chip August 2004. Planning to transfer your VHS videos to DVD with your computer? This project enhances & sharpens the picture, as well as converting to S-Video for a high quality transfer! Kit supplied with through-hole plated and solder masked PCB, case, silk screened and laser cut panels, quality Belden RG58 cable, mains plug pack, Cat. KC-5394 $ .00 and all electronic components. 179 RFID - Secure Access Without Keys! Portable Door Bell Kit Take the doorbell out to the pool! Ref: Silicon Chip Sept ‘04. It uses the wireless transmitter from our witty Remote Controlled Fart Gadget. This means you can take the battery powered receiver out to the backyard with you etc., so you will always here it. Kit supplied with PCB and all Cat. KC-5397 electronic components. $ .95 Requires GH-1088 Fart Gadget - $19.95 14 Valve Audio Preamp Kit Add the warm sound of The Jaycar kit is supplied with genuine Belden RG58 valves to a solid state amp! A/V cable. This cable has a known, consistent Silicon Chip Nov 03, Feb ‘04. propagation delay so you can be confident the Silicon Chip Magazine had propagation delay will be spot on. Beware of inferior said for many years that kits that use cheap "house" brand cable that might they would never publish have wildly variable propagation delay characteristics. a valve circuit. After countless requests, Luxeon Star LED Driver Kit they gave in, and here it is. It Power 1W, 3W, and 5W Luxeon LEDs can be used as a high-gain unit for from a 12V source! musical instruments, or a low-gain unit for Hi Fi Ref: Silicon Chip May ‘04. systems. Kit includes PCBs, case, valve, bobbin, Save $$$ off purchasing core & clips, & all electronic Cat. KC-5370 pre-built drivers. Kit $ .95 components to build a mono unit. includes PCB, and all electronic components. YOUR LOCAL JAYCAR STORE NEW SOUTH WALES Albury Ph (02) 6021 6788 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 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 OPENING SOON NEW ZEALAND 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 Cat. KC-5389 $ .95 29 Add-On Kit 89 Use this kit with KC-5370 for a stereo preamp. It is powered from KC-5370 so another power source is not required. Cat. KC-5371 $59.95 Universal High Energy Ignition Kit Boost performance! Ref: Silicon Chip June 1998. Produces a timed, high energy spark for cleaner and more efficient fuel burning. Kit supplied with PCB, die cast case, and Cat. KC-5247 all electronic components. $ .95 52 Ultrasonic Proximity Detector Kit Save a bundle over pre-built units! Useful at a distance of 10cm to 80cm, it is a great way to help eliminate dented bumper bars and more. Kit includes PCB, a pair of ultrasonic sensors, and all electronic components. Radio Frequency Identity (RFID) is a contact-less method of controlling an event such as a door strike or alarm etc. An ‘RFID Tag’ transmits a unique code when energised by the receiver’s magnetic field. As long as a pre-programmed tag is recognised by the receiver, access is granted. RFID Security Module Receiver Kit Ref: Silicon Chip June 2004. Provides normally open, normally closed electrically switched outputs. Supplied PCB will mount behind standard wall plate. Kit supplied Includes with PCB, tag, and 1 Keyfob RFID tag all electronic worth $9.95 components. absolutely FREE! See below for extra Cat. KC-5393 $ .95 tags. 89 RFID Tags These tags transmit a 40 bit unique code and are EM-4001 compliant. Two styles available: 24 Auto Power-Up Kit A must have for computers and home theatre! Ref: Silicon Chip July 2003. Switches auxiliary appliances on or off when a main unit is switched on or off. Kit includes PCB, case with silk screened lid, pre-cut toroidal core, mains lead and sockets, and Cat. KC-5363 all electronic components. $ .95 69 Credit Card Style Cat. ZZ-8950 $ .95 9 STILL NO. 1 FOR KITS We go the extra mile when putting together our kits. We always include top quality components, and in many cases we supply laser or die-cut screen printed panels, solder masked PCBs and much more. Beware of kit suppliers who do not supply these. If you happen to find a kit of the same quality, at a cheaper price, we will happily match our competitors price, and you still receive all the Jaycar benefits. Fuel Mixture Display Kit for Cars Cat. KG-9158 $ .95 Keyfob Style Is your engine running right? Ref: Silicon Chip Nov 1995. Using the signal from your car’s EGO (exhaust gas oxygen) sensor, you can monitor the air/fuel ratio of your engine. Kit includes PCB and all Cat. KC-5195 electronic components. $ .95 14 Turbo Timer Kit Save your turbocharger! Ref: SC Nov 1998. Automatically idles your engine for a preset time to assist proper cooling of the turbo. Kit includes PCB, case with silkscreened panel, ignition Cat. KC-5254 kill relay and all electronic $ .95 components. 29 Cat. ZZ-8952 $ .95 5 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 Cat. KC-5341 all electronic components. $ .95 49 Programmable Continuity Tester Kit More accurate than a multimeter! Ref: Silicon Chip July 2003. Many DMMs feature a continuity tester, but it is only very rough. This unit allows better testing than the DMM type function. Kit includes PCB, case with silk screened lid, and Cat. KC-5362 .95 all electronic components. $ Limited quantity 29 Neon Tube Sound Modulator Kit Make your neons flash to the beat! Ref: Silicon Chip May 1997. Just a simple connection from an audio input and 12VDC to your 12V neon. Cat. KC-5221 Kit includes PCB and all $ .95 electronic components. 9 PRICES VALID TO 30TH SEPTEMBER 2004 www.jaycar.com.au Online Internet Ordering PRODUCT SHOWCASE DSE Infrared, Ultrasonic Test Gear Dick Smith Electronics have introduced a range of three “AAA” batternon-contact measuring equipment, which the electron- ies which power the ics hobbyist, technician and unit. professional will find highly The laser is not useful. on at all times, for First is an infrared ther- safety (“never look mometer with laser marker a laser in the eye”) (Cat Q1449), so you know but is turned on with exactly what spot the ther- a push-button. The mometer is measuring. unit has auto-powerThe 3-1/2 digit LCD instru- off after 15 seconds. ment takes one reading per It is priced at $98.00. second and can measure from The other items are similar: ultrasonic “tape” measures -30°C to +550°C with an accu- which, as their name implies, use ultrasonics to measure the racy of ±2% of reading or 3°C, distance between them and an object, from 0.6 to 15 metres which ever is greater. It has away. Resolution is 0.01m or 1cm. Each has a 5-digit LCD adjustable emissivity to take readout. into account materials and The difference between the two instruments is that one is surface finishes. fitted with a laser pointer, similar Overall size is Contact: to the infrared thermometer. Again, 170 x 48 x 24mm Dick Smith Electronics (all stores) this allows much more precise and it weighs Reply Paid 500, PO Box 500, measurement, especially over longer less than 120g, Regents Park DC NSW 2143. distances. including the Tel: 1300 366 644 Fax: (02) 9642 9155 Both “tapes” are the same size, 123 Website: www.dse.com.au x 60 x 39mm and both are powered by 9V batteries. The 88g laser model, Cat Q1507, Wireless PC Lock protects data from prying eyes sells for $99.94, while the 68g nonlaser model, Cat Q-1518, sells for Do you ever wonback within range. $49.94. der about other eyes One transmitter can All are available from DSE and viewing sensitive share several comTandy stores, PowerHouse, mail/ data on your PC puters. phone orders or via the DSE webwhen you’re away Once the computsite. from it? Someone er enters the ‘Lock rifling through your Mode’, a password private files after you is required to use go home? Finding the computer if the those photos you’d transmitter is unarather not anyone vailable. 60VA to 3KVA encased toroids else see? If an unauthorWhether it’s to stop the casual ised person tries to bypass the lock by snooper or real industrial espionage, rebooting the computer it will remain this fully automatic computer lock locked, and can only be unlocked by a from Microgram will prevent anyone password. Furthermore, if the PC lock accessing your computer when you’re is removed either when the computer away from it. A USB stick “receiver” is on or off, the password is required. plugs into the PC while a small, The Wireless PC Lock (8545-14) battery-operated 434MHz transmithas a recommended retail price of ter is worn by the user. Battery life is $79.00. estimated at 2000+ hours. Contact: The computer automatically enters Microgram Computers ‘Lock Mode’ when the transmitter is 1/14 Bon Mace Cl, Berkeley Vale 2261 Harbuch Electronics Pty Ltd more than 2m away from the computer Tel: (02) 4389 8444 Fax: (02) 4389 8388 9/40 Leighton Pl. HORNSBY 2077 and it automatically resumes normal Website: www.microgram.com.au Ph (02) 9476-5854 Fx (02) 9476-3231 operation when the legitimate user is STEPDOWN TRANSFORMERS siliconchip.com.au September 2004  53 High power, pure sinewave inverter/UPS Altronics have released new stateof-the-art 1500W pure sine wave inverters from Invertek, which perform the functions of a battery charger, inverter and solar regulator in one. An inbuilt automatic bypass switch allows them to be employed in backup 240V power installations. Where mains power is available, it can be connected to the unit, allowing it to function as a battery charger for maintaining the connected battery bank. Under normal conditions, the mains is connected through to the 240V outlet. If the mains fails, the bypass switch automatically and seamlessly (within 20ms), switches the inverter output to the outlet, maintaining 240V power to the connected load at up to 1500W continuous. Recommended retail price for the Invertek 1500W Inverter (M8155) is $1390.00. Contact: Altronics PO Box 8350, Perth Business Centre 6849 Tel: 1300 797007 Fax: (08) 9428 2187     Website: www.altronics.com.au Pico release USB interface oscilloscopes Pico Technology, represented by Emona Instruments, has released the PicoScope 3000 series of USB2.0 interface oscilloscopes. The PicoScope 3000 range are PC-based oscilloscopes that connect to a PC via the PC’s USB interface. With high bandwidths, fast sampling rates, large buffer memories and lightning fast data transfer, the PiscoScope 3000 series are ideal for laboratory or field service applications. The PicoScope 3000 series are available in three models ranging from the Model 3204 with 50MHz bandwith, 50MS/s and 256K record length through to Model 3206 with 200MHz bandwidth, 200MS/s and 1MB record length. They feature more than 30 automated measurements such as frequency, pulse width, rise time, THD and SNR, and five enhanced display modes including Digital Colour (ideal for spotting intermittent glitches in digital signals) and Analog Intensity (useful for displaying video waveforms and analog modulation signals). The benefits of interfacing an oscilloscope to a PC’s USB interface include: a fast data transfer rate which ensures 54  Silicon Chip a quick screen update rate, waveforms are stored directly to the PCs hard disk with only the size of the hard disk as a limitation, waveform images can be exported as jpegs for use in reports, email or web posting and waveform images and instrument settings are easily saved and shared between users. Sharp’s new home theatre projector Sharp today announced a new $2499 Home Theatre Projector designed specifically to display widescreen DVD images. The XV-Z10E boasts a resolution of 854x480 pixels, allowing true 16:9 reproduction to get the best out of DVD movies and 1000 ANSI Lumens . A joystick-like control called the “Lens Shift” makes it easy to set the projector’s 1:125 short-throw lens to display a 100” image over distances between 3.0 and 3.8m, while a sixposition memory preserves these settings for instant setup in your favorite viewing spots around the house. Images from 25” to 200” can be displayed. Input can be accepted from computers and PAL or SECAM video sources. HDTV compatibility is built in. The projector can also be switched between 4:3 or 16:9 aspect ratios and offers an Eco mode to extend bulb life to 4000 hours while keeping fan noise to just 32 db. The unit weighs just 2.7kg. Contact: Contact: PO Box 15, Camperdown NSW 1450 Tel: (02) 9519 3933 Fax: (02) 9559 1378 Website: www.emona.com.au PO Box 643, Mona Vale NSW 1660 Tel: 1300 135 530 Website: www.sharp.net.au Emona Instruments Pty Ltd Sharp Vibration, shock dampener for computers, etc. The GELShock-2 shock and vibration dampener from Intelligent Systems Australia Pty Ltd is designed to provide significant protection for rackmount computers against shock and vibration. The GELShock-2 is a rackmount device itself and takes up 1RU of rack space. It mounts into the standard 19” rack cabinet on its own telescopic slides. The rackmount computer is secured to brackets on top of the GELShock-2, providing a ‘floating platform’. It effectively reduces vibrations over a wide frequency range (including micro vibrations) and also absorbs shock. The unique design of the GELShock-2 uses aGEL insulators for load support and dampening in the vertical plane. aGEL chips are used for dampening in the horizontal plane. The GELShock-2 is suitable for most rackmount computers that are 2RU, 3RU or 4RU in height and weigh between 12kg and 25kg. Contact: Intelligent Systems Australia PO Box 635, Cockatoo, Vic 3781 Tel: (03) 5968 0117 Fax: (03) 5968 0119   Email: info<at>intelligentsystems.com.au siliconchip.com.au 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. No longer do you have to wade through search engines or look through pages of indexes – just point’n’click and the site you want will open! Your company or business can be a part of SILICON CHIP’s WebLINK . For one low rate you receive a printed entry each month on the SILICON CHIP WebLINK page with your home page graphic, company name, phone, fax and site details plus up to 50 words of description– and this is repeated on the WebLINK page on the SILICON CHIP website with the link of your choice active. Get those extra hits on your site from the right people in the electronics industry – the people who make decisions to buy your products. Call SILICON CHIP today on (02) 9979 5644 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 We endeavour to provide a range of technical books of interest to the Radio Amateur as well as electronics enthusiasts, at competitive prices. Special discounts are offered to WIA members. We are the only bookshop of this type in Australia. Tel:(02) 9689 2417 Fax: (02) 9633 1525 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. For everything in radio control for aircraft, model boats and planes, etc. We also carry an extensive range of model flight control modules including GPS, altitude and speed, interfaces, autopilot and groundstation controllers. More info on our website! JAYCAR JAYCAR ELECTRONICS ELECTRONICS Tel: Tel: 1800 1800 022 022 888 888 WebLINK: www.jaycar.com.au WebLINK: www.jaycar.com.au TeleLink Communications Wireless Institute of Australia (VK2) Tel: (03) 9762 3588 Fax: (03) 9762 5499 WebLINK: jedmicro.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. Tel:(07) 4934 0413 Fax: (07) 4934 0311 WebLINK: telelink.com.au WebLINK: wiansw.org.au/bookshop/ Silvertone Silvertone Electronics Electronics Tel:(07) 4639 1100 Tel/Fax: (02)Fax: 9533(07)4639 3517 1275 WebLINK: www.silvertone.com.au WebLINK: silvertone.com.au 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 Pty Ltd Tel:(02) 9939 4377 Fax: (02) 9939 4376 Tel:(02) WebLINK: avcomm.com.au WebLINK: avcomm.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 . ...for the Older Generation How to Find Anything on the Internet for the Older Generation A few months ago, we mentioned that Jaycar ElecInternet Banking and Shopping for the tronics introduced a couple of computer books speOlder Generation cifically written for the older generation: larger type, Creative Gardening with a Computer easy-to-understand language and so on. for the Older Generation Now the range has been rather significantly expanded. All six titles sell for the same price ($29.95) Contact: and now include: Jaycar Electronics Computing for the Older Generation PO Box 6424, Silverwater NSW 1811. The Internet for the Older Generation Digital Photography and Computing for the Older Tel: (02) 9741 8555 Fax: (02) 9741 8500 Website: www.jaycar.com.au Generation siliconchip.com.au SC September 2004  55 SERVICEMAN'S LOG You have to be versatile in this game Versatility is the name of the game when it comes to servicing. In this business, you not only have to sometimes deal with frustrating faults but with frustrating customers as well – especially those who want everything “on the cheap”. A well known audiophile technocrat lives not far away from our workshop and owns an ancient Philips KR638 (KL9A-1) with a wooden cabinet (do you remember those?). He complained of an intermittent “no-sound” problem which he and his family had been putting up with for nearly two years. This was because it had taken this long to build an extension to his house, which is at the end of a long steep drive and we couldn’t arrange to pick the set 56  Silicon Chip up until the concrete had been laid and dried. Now we had all been watching this development with great interest at the strange goings on. For example, there was the time he mowed the grass beautifully just before the builders arrived and heaped all their junk on it. As for us, we concluded that the main reason it took so long to pour the concrete for his drive was so that he could lay “jumbo cable” in conduits underneath it. But was this for sound or concrete reinforcement? As mere bystanders, this seemed to us to be taking “audiophilia” to extraordinary lengths. Anyway, the situation with the telly finally became so bad that the only sound they could hear was through the headphone socket and then only on one channel. As a result, only one person in the household could listen at any one time. It was a case off “first in, best dressed”, with the rest of the family left to lip-read! This finally forced them to do something about the problem and so the set eventually arrived at the workshop and a loan set despatched. Personally, I am very fond of these particular sets, most probably because of their ease of access. Anyway, it didn’t take too long to remove the rear quarter panel and slide out the audio amplifier board, which revealed monstrous dry joints on all the audio output ICs. Resoldering them restored the sound but the picture wasn’t too good, with intermittent lines and poor focus. Examining the main board revealed many more dry joints, especially around the focus control. Having attended to this, the picture was now quite good and I let it soak test before putting the back on. I then switched the set back on again and gave it a whack on the top, just to reassure myself that all was now robust and sturdy. Unfortunately, this hearty slap on the cabinet murdered the set, so I removed the back and found I had blown the 2A mains fuse. Well, how do you do that with a “bit of a whack”? It turned out that the degaussing dual posistor was also dry-jointed and the vibration caused it to draw more current than the fuse could stand. Resoldering it and replacing the blown fuse finally fixed it properly. In the meantime, our audiophile decided that the loan set, some 15 years its junior, really did give a better picture and so he bought it from us. The old Philips has been relegated to siliconchip.com.au the rumpus room but at least it now gives stereo sound and you don’t need headphones. The question on everyone’s lips is does the concrete driveway have 5.1 Dolby surround sound? And where is the sub-woofer buried? And will this help with the parking? A gorgeous model One day, this gorgeous-looking model glided into the shop – and I’m not talking about the Panasonic stereo she was carrying. She asked me whether I could fix it for her and I demurely replied that I would fix anything for her if she so wished. At that point, Mrs Serviceman shoved me aside and rudely (I think) monopolised the conversation, pausing only occasionally to glare at me. At the time, I thought I was just being polite but she (Mrs Serviceman) later informed me that my tongue was actually dragging along the floor. There is no justice in this world! Unlike her (the model), the Panasonic unit was a middle-of-the-road SA-PM01 stereo system and she was complaining that the CD door clunked loudly when opening and closing. She had taken it to two other service companies who had had it for a long time and now the CD didn’t work at all. Well if you saw her, you’d want to have her – er, I mean it – for a long time too. Anyway, under strict supervision, Mrs Serviceman made sure I was going to do the right thing at all times. When I had stripped it down, I found that someone had taken an awful lot of time and trouble to install the flexi-cable the wrong way around into the connector (he too must have been distracted) and this was why the CD wouldn’t work. The original problem was due to broken gears on the lid assembly, which is a recognised problem with this model. Replacing five components in the gear assembly usually fixes it for good (Part Numbers: REE0880, FKF0561-K2, RMA1291, XTV3T6JF2, RDG0473). I was all for personally returning the unit to its owner after hours but unfortunately, the thought police scuppered that idea as well. A real mystery One of my main breadwinners is repairing Philips A10 chassis TVs and I have written a lot in the past about siliconchip.com.au their “Small Signal Panel/Board”. The other day I had an interesting side event involving a 29PT6361/79B and a Mrs Evans. This set – in an unusual black cabinet set (early production?) – came in for the usual intermittent “no remote” and “dead” symptoms. The repair was quoted for and accepted, and so an exchange module was ordered and fitted. The set was then aligned and tested before being delivered back the customer. However, the twist was that Mrs Evans phoned a few days later to report that all was going fine, except that (and there always is an exception) the “Rotation” control in the Features menu wasn’t working. Apparently, the control could be adjusted with the remote via Items Covered This Month • • • • • • • Philips KR638 (KL9A-1) Panasonic SA-PM01 stereo system Philips 29PT6361/79B A10 chassis Philips 21PT3822/79T (L9.2A chassis, BZ production) Sony KV2185 S (G3E chassis) NEC FS-6807S Panasonic TX-33V2X (M16 chassis) the on-screen display but nothing was happening to the picture. I have to admit that I didn’t even know about this feature on this particular model – it’s normally only fitted on the 34-inch version. As you’ve probably realised, it’s designed to correct for the effect of the Earth’s magnetic field on the picture tilt (the effect is more noticeable on large screen sizes). I decided that the best place to tackle this problem was back at the workshop. And sure enough, Mrs Evans was absolutely correct and very knowledgeable – the picture would not tilt at all, although the on-screen display said it should be doing so as you pressed the remote. So was this a microprocessor/ EEPROM software problem, or was it hardware? I checked for error codes but there were none, so I examined the hardware to see if I could find anything visible like coil plug 0252/0235 and 0234 being left unplugged when the chassis was refitted. To my amazement, I discovered that there was no rotation coil fitted and neither was the necessary accompanying circuit installed at all in the set. What’s more, no-one had taken it out as it was just never manufactured with it. At this stage, I decided to go back into the SAM (Service Alignment Mode) menu and check the option codes. Unfortunately, though, Philips September 2004  57 Serviceman’s Log – continued seem to no longer stick the option codes list inside their sets, so now you have to look up the Product Survey for the year the set was manufactured (2000). In fact, the PS2000-4 Yearbook is the best place to go for this latest information. This laborious process, which is really only available to dealers, revealed that the options should have been 123 253 255 159 and 214 for this particular model. However, this set’s option byte value OB5 was 246 (for the 34inch) instead of the published 214 (for the 29-inch). Going through the option code menu item by item, I eventually found what I was looking for. Option Abbreviation “ROTI” (Rotation) was ON (=1) and this option bit 6 gave a value of 32. Switching it off produced the correct option byte value for OB5 of 214 (214 + 32 = 246). In my opinion, the way Philips has presented this in their service manual is very confusing, especially as their list on pages GB78 and 79 seems to be in the wrong order (in particular OB4 and OB5). Anyway, this was the easy part; the hard part was explaining to Mrs Evans that she had in fact never paid for nor received this particular feature, even if it is shown on page 27 of her instruction booklet (though to be fair, it does say “Note: applicable to certain models only”). If only Philips wouldn’t produce generic versions of this covering more than one model. Obviously, when the Small Signal Panel was replaced, this feature had been left inadvertently enabled – most probably for the 34PT6361/79R with more features. Murphy’s Law Mrs Rodger’s brought her 1999 Philips 21PT3822/79T (L9.2A chassis, BZ production) in at a particularly busy time, when the usual people who book the work in were otherwise engaged. As a result, the fault stated on the job sheet was simply to the effect that the set was dead. After removing the back and checking the fuse, it didn’t take long to find 58  Silicon Chip that there was no output from the power supply. A quick check then showed that diode D6550 (BY229X-600) which feeds the main supply (VBatt – 95V) was short circuit. Unfortunately, this being a flat pack diode, I had to wait until a new one was ordered in. In the meantime, I was also repairing another similar Philips TV with a faulty flyback transformer. To replace this, the chassis had to be removed to gain access to the PC board tracks. There aren’t all that many plugs to be reinserted afterwards when rein- stalling the chassis but they are all unmarked. Usually, however, it’s just common sense – most plugs marry up with the correct socket due to orientation, size or colour. However, when I switched this set on, it was now inexplicably dead. It took a long time to figure out that the cause was the top control panel and by unplugging it, I could make the set work. The control panel is a very simple assembly with a collection of four microswitches and a 3-core cable connecting it to the main chassis. How could this cause the set to go dead? Well, it took nearly an hour for this old idiot to realise that there was in fact nothing wrong with the assembly – I had inadvertently plugged it into the wrong socket. Once this mistake had been corrected, the set worked perfectly. Getting back to the first set, the replacement BY229X-600 diode arrived in due course and I was annoyed to find that it made no discernible difference – the set was still dead. As a result, I spent a long time checking out this TV from stem to stern. The flyback transformer and transistor were OK with no shorts and there were no shorts on any of the other voltage rails. I then discovered that power was getting to FET 7518 and IC 7520 (MC44603A) but the start-up voltage was low. I checked almost all the components in this simple switchmode power supply – admittedly in-circuit – but everything appeared to be OK. I then began to get desperate and replaced the IC and FET but it still wouldn’t fire up. I even ordered and replaced the chopper transformer 5545 in case that was shorting inside but again it made no difference! By now, I was running out of ideas, so I decided to start from scratch again and check all the components out of circuit. And this time I did find something – diode D6540 (BAV21) was leaky. I replaced it and at long last there was voltage coming out of the power supply – but otherwise the set was still dead. With the power supply now working, I went back to the line output stage and found that transistor Q7400 (BF422), the line driver, was open circuit. I replaced it but still no joy. You would have thought by now that I would be at least a little closer to a result but this wretched set was going siliconchip.com.au to fight me all the way. Next, I discovered that there was a problem in the startup circuitry which was preventing any horizontal drive to Q7400 (via Q7608). This latter transistor was switched off by IC7607 NE555D. Mrs Rodgers was by now becoming annoyed at the long delay and I was thoroughly frustrated with the extent to which this set had been damaged. Finally, I got to talk with her and it turned out that this set may have suffered a power surge from a lightning strike during a storm. Armed with this information, we mutually agreed it would be best to write this set off and approach her insurance company for a replacement and we would keep the old set for parts. And that’s what happened. Many weeks later, when business was quiet, I decided to give it one more look over. While plugging the set back in, I noticed that in fact there were two places the lead to the side control panel 3-pin socket (0251) could plug into – either position 0267 on the main chassis or 0248 or the module on the lefthand side. I was now beginning to hear a bell ringing somewhere in the back of my mind and thought it was worth investigating how this should really be hooked up. However, this wasn’t as simple as it sounds. Because of the way Philips like to draw their manuals for each chassis and include all the variants for all the models they make world-wide, it can get pretty confusing. However the circuit shows the unmarked plug going from 0251, the audio output socket Ext1, to either 0260 on the main chassis or 0248 to the sound panel. There is no note in the diversity table but fortunately 0260 was a 4-pin socket and 0248 was a 3-pin socket on the ITT Audio decoding panel D1. 0267 on the other hand is the data communications socket for an external computer (COMPAIR). Connecting these two sockets causes the centre pin (SCL) to be connected directly to ground, which would be like killing one half of your brain. Correctly connecting the sockets (0251 to 0248) fixed the problems, the set bursting into life with perfect picture and sound. Of course, I could blame myself for not remembering having done this before and condemning this set to be written off because of it. Alternatively, I could blame the idiot who designed this ambiguous arrangement where one unmarked plug could easily be plugged into two different locations. Even giving the same number identification to both sockets would have helped. And as for the service manual, it just confuses the situation even more. Obviously, they have never heard of Murphy’s Law. I wonder how many other technicians have fallen into this trap? The harder you try . . . I find sometimes that the harder you try to do the right thing, the worse the outcome. On other occasions, the opposite applies – you just do a basic, simple operation and everything just falls into place. To illustrate this, a 1993 Sony KV2185 S (G3E chassis) came in with the complaint that the picture “went black”. The client also stated that he didn’t wish to spend much money (who does?) on an otherwise small and old TV. I have repaired a lot of this series of TV and know that the siliconchip.com.au September 2004  59 Serviceman’s Log – continued G3E was not Sony’s best product when it comes to reliability. Nevertheless, the first thing I noticed about this set was that the fault was intermittent (the worst scenario). My first step was to get stuck into the set and repair a large number of dry joints all over the board. That done, the set performed faultlessly but despite my best intentions, I was not in a position to say exactly where the fault lay. Satisfied that the problem was solved, I replaced the back and put the set aside to soak test. Apart from that, the door flap that hides the front controls had broken hinges and so a new one was ordered. It took a couple of weeks for them to inform us that the door flap was no longer available, so the client was notified that the set was ready. He called a week later to pick it up, by which time the set had been running perfectly every day for over three weeks. But three days later, an unhappy client returned the set with the same fault. There was one important difference, however – this time the fault was permanent. Despite our mutual disappointment, I was at least glad to be given a second opportunity to crack the case. I started by checking all the voltage rails and found them all to be spot on. What’s more, the picture was fully scanned and the On Screen Display (OSD) was present. However, every few seconds, the OSD would appear to roll and retrace lines would appear as though there was no sync. In addition, there was no video output from the jungle IC, either in the TV or AV modes. A quick check with the oscilloscope showed luminance, chrominance and clean sync pulses arriving at IC301 (CXA12138S), along with the blanking pulses. All crystal frequencies checked out, as did the all the voltages around the IC apart from the RGB outputs on pins 39, 38 and 37. In the end, there was nothing else 60  Silicon Chip to do but change this $70 48-pin highdensity jungle IC, which fortunately fixed the fault. After another week of soak testing, it went home to its owner – hopefully for longer than three days this time But why did it fail after it had been tested for so long in the workshop and then so soon after it had gone home? It just doesn’t seem fair! Usually, such faults are discovered and rectified without any prolonged testing and you never hear of them again. There is no justice! The elderly NEC I was asked by Mr Beaumont to fix his mother’s television. He warned me that the set was getting old and she was a pensioner and really couldn’t afford to spend much money on it. Not being a registered charity just yet, I enquired as to how he defined “much money” to which he replied “about $150”. Of course, I am not a soothsayer and can’t really guess what it is likely to cost to fix an unknown TV located at his mother’s house. Instead, I told him that it would cost a service call for him to find out if I could fix it within a reasonable amount, after which she could make up her own mind. He thought that this would be OK and so I phoned her to make an appointment. At the same time, I also managed to get the TV model number from her. The set turned out to be a 1999 NEC FS-6807S that was pulsating but otherwise dead. Examining the copper side of the main board (PWC-4277) was difficult in the cramped surroundings but I could see a lot of dry joints, so perhaps I could fix this TV within half an hour. Before I had even taken the back off, Mrs Beaumont, who never left the room, kept anxiously asking me what the problem was. However, I learnt a long time ago not to say what you think the problem is until you are certain of siliconchip.com.au the facts. Unfortunately, Mrs Beaumont was persistent and after brushing off a few more questions, I was beginning to get frustrated with her for implying that I didn’t really know what I was doing. It’s an all-too-familiar theme – “surely you must know by now exactly what’s wrong?”. Well, there really were lots of bad dry joints, especially on IC501 and IC502, the 5V and 9V regulators, the transformers and power transistors, the switchmode power control IC (IC601, STRF6524) and transistor Q507 (2SB546). Unfortunately, resoldering these failed to fix the pulsating problem and nor did it stop the persistent questioning. By now, I had been going for well over half an hour. Q507 looked as though it had been getting hot and measured leaky between collector and emitter so I replaced it but still no result. By now, I was under some pressure, considering the restraints put on me regarding cost. And that – coupled with the never-ending barrage of “surely you know what’s wrong by now?” – made it difficult to think straight. This set really needed to be in the workshop, where I could get some peace and quiet apart from anything else. By now, I suspected the line output transformer (T502), although I hadn’t eliminated the power supply as I wasn’t sure whether it was a load problem or a supply fault. I also had very little in the way of test equipment siliconchip.com.au with me but I knew that she wouldn’t accept the cost of a workshop repair. In the end, I decided to have one more go at the power supply and concentrate on the electrolytic capacitors. As luck would have it, apart from the main filter capacitor (CC603), there’s just C621 (100µF 63V) and I just happened to have one in my toolbox. I soldered the new capacitor in and held my breath while I switched the set on. The set sprang into life and I could breathe again. But that wasn’t to be the end of my problems. After doing a few sums in my head (I had been there an hour by then), I very calmly explained what the problem was and told her that it would only cost her $100! I thought she would be delighted with this news but far from it. Instead, I got the full repertoire – “couldn’t I do it for less?” and “I’m and old age pensioner” and “what about less for cash”, and “it’s not worth it” and “what about the guarantee?”. I was really quite dumbfounded. The repair was really worth a lot more than I was asking and I had come in at a lot less than their $150 ceiling By now I had had enough. It was $100, take it or leave it. Her 68cm set was only five years old and worth a lot more than $100. Begrudgingly, she accepted the cost and made me reinstall the TV and the video and berated me about the reception (which was all my fault) before opening her wallet and taking out a crisp new $100 note from a wad that would choke a horse. I was only too happy to be out of there. I guess it takes all sorts! Flickering Panasonic An 80cm 1995 Panasonic TX-33V2X (M16 chassis) arrived on my bench with the complaint that the picture flickered up and down when cold and cut out when hot. Of course, when I switched it on, it worked perfectly. Nevertheless, being pretty familiar with this model by now, I quoted to replace the 330µF capacitors (C885/C889) on the 5V rail and just for good measure, the (sometimes) dried-out 0.47µF 160V capacitor (C760) that smooths the horizontal drive supply. I also included the time necessary to resolder any dry joints on the vertical IC (IC451). The quote was accepted and I did the work required, which wasn’t easy with such a heavy TV set with such poor access. I then left it to soak test but an hour after doing the work, the picture started to show line tear, with ragged edges down the verticals. Brilliant. It took another hour to find that secondary smoothing capacitor C580 (220µF 200V) was open circuit. This capacitor is on the X Board, which supplies 140V to the line output stage. The large cylindrical capacitor looked brand new but it actually rattled inside its case! SC So much for the breaks! September 2004  61 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 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 Programmable ROBOT This Programmable Robot features full manoeuvrability – forward, reverse, turn and stop, with pulse-width modulation for speed control. It also sports bump-and-respond, random motion, programmable sound, light sensing (16 levels) and EEPROM byte-wise addressing. By THOMAS SCARBOROUGH T HIS CIRCUIT lets you design your own robot to suit your own taste. It would not be difficult, for instance, to convert this design to a credible R2D2, without any modification to the PC board. With a little imagination, the possibilities would be even wider. The circuit could operate a pulley system, serve as a line-tracker or rotate motors in response to broken beams of varying intensity, without modification to the PC board. As noted, the robot is programmable. Therefore, the drive circuit is merely a slave to the software and is of a relatively simple design. The circuit is based on a PICAXE-08 micro, as has been featured previously in SILICON CHIP. Although more limited than a “raw” microcontroller, it is a small marvel nonetheless – both for cutting out the need for a costly programmer and for placing respectable power at the service of the constructor with great simplicity. All that the Programmable Robot requires in its support is a PC and a serial cable. The programming software is free (www.rev-ed.co.uk) and comes in the form of a telegram-style BASIC and flowchart programming. Note that the Programmable Robot’s memory is limited – not all the features listed above can be used at the same time. However, with careful programming, the robot will perform most dual or even triple tasks with aplomb. As an example, light-seeking, bump-andrespond and sound can all be incorporated in a single program. Table 1: PICAXE Motor Control Outputs Pin 7 (P0) Pin 5 (P2) Pin 3 (P4) High Low Both motors on Left motor backwards Right motor backwards Both motors off Left motor forwards Right motor forwards 64  Silicon Chip This table shows the most important PICAXE-08 outputs – ie, for motor control. Since the PICAXE-08 microcontroller represents the Programmable Robot’s “control room”, this is where we shall begin. Unfortunately, the PICAXE-08 is confusing in its pin numbering, which has become something of a legend in its own time – therefore we shall resort to the standard IC pin numbering here; ie, pins 1-8, with pin 1 being situated next to the small indentation on top of the IC. Circuit details The complete circuit is shown in Fig.1. The PICAXE-08’s pin 1 (+V) and pin 8 (0V) are connected to a 6V battery via switch S2 and diode D2. D2 serves a dual purpose – firstly, to prevent reverse polarity, which could do considerable damage, and secondly, to drop the supply voltage to about 5.4V, which is more suitable for the PICAXE-08. Pin 7 (P0) is designated by the manufacturers for output only and is used to switch both of the motors on or off at the same time. It may also be used to pulse the motors on and off (pulse-width modulation) for speed control or special effects. When it is “high”, the motors are on; when it is “low” they are off. siliconchip.com.au Pin 5 (P2) is designated for input or output. In this circuit, it is used for output only and controls the direction (forward or reverse) of the lefthand motor, as seen from the rear of the robot. Pin 3 (P4) is likewise designated for input or output and is used here to control the direction (forward or reverse) of the righthand motor. Note that neither pin 5 nor pin 3 will accomplish anything unless both motors are switched on first via pin 7 (P0). Both pins 5 and 3 cause a wheel to roll forwards when it is “low” and backwards when it is “high”. Pins 7, 5 and 3 together may be used not only to make the robot drive forwards or reverse but also to turn, gyrate, wiggle, judder or do virtually anything else one may think of! These motions may also be strung together sequentially, as part of a programmed sequence (within limits, since memory is at a premium). Pin 4 (P3) is designated for input only and is used to sense collisions through the Programmable Robot’s bumper bar. The robot need not only do a simple reverse-and-turn but may be programmed to respond in various ways. Pin 6 (P1) is designated for output, input or analog input. In this circuit, it is used only for output and analog input. In “output” mode, it is used to drive a piezo sounder for programmable sound. The piezo sounder will beep, play tunes or with a little ingenuity, create sound effects such as a police siren or a cat’s purr. In “analog” mode, pin 6 reads the light level at the front of the robot. Note that this first requires the correct adjustment of VR1 with the help of the LDR ADJUST program. The robot is capable of detecting sixteen levels of light which may be used for light-seeking (or light-avoidance), line tracking and day-night sensing. Several short programs are provided, including a FIGURE-8 DEMO, LIGHT & BUMP DEMO, PWM DEMO, RANDOM DEMO and WALTZING MATILDA DEMO. The WALTZING MATILDA DEMO Fig.1: a PICAXE-08 microcontroller, 10 MOSFETs and not much else comprise the circuit of this robot. All the intelligence is contained in the micro’s software. siliconchip.com.au September 2004  65 Fig.2: follow this parts layout diagram when assembling the PC board. has been designed not only for fun but as a “get you going” program during assembly, while the LIGHT & BUMP DEMO will give the best overall functionality. This seeks out light and drives towards it, reverses and turns away from obstacles, as well as having sound. For the sake of clarity, the most important PICAXE-08 outputs are listed in Table 1. Pin 7 (P0) activates both motors simultaneously via MOSFETs Q2 & Q5. These two MOSFETs are wired in parallel and these should work satisfactorily with a small heatsink for the small motors used here. While D2 can cope with two 9W motors, the prototype’s motors used about 1.6W each under load. If the drain on the battery is too Fig.3: this is the full-size etching pattern for the PC board heavy when the motors are switched on, this could lead to a voltage drop which could make the PICAXE-08 do strange things. Therefore, the battery should be suitably rated for powering the motors. The prototype used a 6V 4Ah battery. AA batteries in series are unlikely to be adequate, except for the most lightweight of motors. Pin 6 (P1), used in “output” mode, drives piezo sounder X1. Since VR1 and LDR1 are connected to the same pin, 330Ω resistors are included as protection for these components. In analog mode, pin 6 monitors LDR1 and the PICAXE-08 interprets the voltage as 16 discrete levels, between <0.22V (level 1) and >3.38V (level 16). Ideally, the darkest areas of a room should read about 3.6V at pin 6. This can be arranged by means of the LDR ADJUST program (see below). A value of 10kΩ for VR1 should prove suitable if the specified NORP12 Light Dependent Resistor (LDR1) is used. Virtually any other LDR may be used but the value of VR1 may need to be modified to match, in order to provide a voltage of about 3.6V at pin 6 when surveying the darkest areas of a room. If the resistance of the LDR in darkness is known, VR1 should be adjusted to roughly 70% of this. It might be asked what use a single LDR is, since it would seem that two LDRs would be required to compare light level from different directions. However, since LDR1 is mounted on a moving platform, light levels from different areas can be compared over time. Thus the robot measures light level in one part of the room, stores Table 2: Resistor Colour Codes o o o o o No.   3   4   1   2 66  Silicon Chip Value 47kΩ 22kΩ 10kΩ 330Ω 4-Band Code (1%) yellow violet orange brown red red orange brown brown black orange brown orange orange brown brown 5-Band Code (1%) yellow violet black red brown red red black red brown brown black black red brown orange orange black black brown siliconchip.com.au Parts List The completed PC board is secured to the base using machine screws and nuts. Note the heatsink that’s fitted to the tabs of MOSFETs Q2 & Q5. it, then turns to measure light level in another part of the room. The different light levels can then be compared and the robot can respond accordingly. Pins 3 & 5 switch two power Mosfet H-bridges (Q3, Q4 and Q9,Q10) to control the direction of the motors (forward or reverse). The two 100nF capacitors and diode D1 are included to suppress interference. Transistors Q1 and Q8 are used as inverters, so that when the “forward motion” MOSFETs are disabled, the “reverse motion” MOSFETs are activated. Pin 4 is normally held low by its 47kΩ resistor. When bump-andrespond switch S1 (the bumper bar) is closed, pin 4 is pulled high. The 10µF capacitor and the 47kΩ resistor determine how long a bump will be “remembered” and the values of these components may be modified as desired. These components are required because the software, as it executes, may need a moment to reach the program line which monitors the status of S1 – and because there is bound to be some switch-bounce, too. Pins 2 (Serial In) and 7 (Serial Out) are used for downloading programs, with pin 7 doing double duty for switching the motors, as described above. Since pin 7 does double duty, the robot’s motors may twitch a little as a program is downloaded or debugged. A 220µF capacitor provides supply decoupling and the 22kΩ bleed resissiliconchip.com.au tor ensures that the circuit powers down properly when switched off, so that there will be no unpredictable behaviour when it is switched on again. After switching off the robot, allow a few seconds for the 220µF capacitor to discharge before switching on again. PC board assembly All the parts, with the exception of the bump switch, LDR, piezo sounder and battery, are mounted on a PC board coded 07209041, measuring 92 x 67mm. The component overlay is shown in Fig.2 and the wiring details in Fig.6. PC board and hardware construction are inter-linked and both of these sections need to be read first before final construction of the robot is undertaken. The following procedure is recommended when soldering components to the PC board: (1) solder the 14 PC pins (insert these from the copper track side), as well as the wire links; (2) solder the 8-pin dual-in-line (DIP) socket (observe the correct orientation) and CON1; (3) solder the 10 resistors and preset potentiometer VR1; (4) install the two diodes and the two electrolytic capacitors, taking care with polarity; (5) install the two 100nF capacitors; (6) solder in the two transistors (Q1 & Q8) and the 10 MOSFETs; (7) fit a small heatsink to MOSFETs Q2 & Q5. Robot platform The physical construction of the 1 Masonite baseboard, 200 x 160mm 1 PC board, code 07209041, 92 x 67mm 1 piezo sounder (without integral electronics) (X1) 1 bumper switch (S1 – see text) 1 miniature toggle switch (S2) 1 10kΩ trimpot 1 NORP-12 light dependent resistor (LDR1 – see text) 1 3.5mm PC-mount stereo jack socket (CON1) 2 reversible 6V geared motors (ideally <2W each under load) 1 8-pin DIP socket 1 6V 4A.h SLA battery 2 spade connectors to suit battery 14 PC stakes 2 60mm wheels (to suit gearbox shafts) 1 40mm rear wheel 130mm 2.5mm steel wire for rear wheels 4 corner brackets for battery Semiconductors 1 PICAXE-08 microcontroller (IC1) 10 MTP3055V N-channel MOSFETs (Q2-Q7,Q9-Q12) 2 BC547 NPN transistors (Q1,Q8) 1 1N4004 silicon diode (D1) 1 1N5404 silicon diode (D2) Capacitors 1 220µF 16V PC electrolytic 1 10µF 16V PC electrolytic 2 100nF (0.1µF) MKT polyester or ceramic Resistors (0.25W, 1%) 3 47kΩ 1 10kΩ 4 22kΩ 2 330Ω Also required PICAXE Programming Editor software – available free from www.picaxe.co.uk PICAXE download cable (Part No. AXE026) – available from MicroZed 02 6772 2777; see www.microzed.com.au Programmable Robot begins with a suitable baseboard to which everything else is attached. The prototype’s baseboard measured 200mm from September 2004  67 Fig.4: a swivel wheel is used at the rear of the robot for simplicity of steering. front to back and 160mm wide. I used Masonite, a strong material that is easy to work with. Two reversible 6V DC geared motors with “through-shafts” were bolted to the baseboard. The platform of the prototype was raised a little above the motors with 10mm square wood dowels, to provide more vertical room for the rear swivel-wheel. The motors I purchased use about 250mA under load and at 6V run free at about 6000 RPM. I divided this down to 70 RPM with the gearbox and this comes down to perhaps 50 RPM under load, when the voltage drop via D2 is taken into account. 60mm diameter gear wheels were used for the two drive wheels and these could simply be pressed onto the drive shafts. The motors are mounted so that they each “face the same way” 68  Silicon Chip as they turn – that is, their drive shafts both turn the same way when the robot is moving forward. This is because there may be inequalities in the forward and reverse speeds of DC motors and this ensures that the robot will drive in a reasonably straight line when the motors are activated. Next, attach leads with spade connectors to suit the battery and connect the motors as well. That done, attach LDR1 at the front of the robot by means of suitable wires. A short tube over LDR1 is required for directionality (see below). You also need to attach bumpand-respond switch S1 (ie, the bumper bar – see below), the piezo sounder and switch S2 using suitable leads. Finally, insert the PICAXE (IC1) in the DIP socket. Once the assembly is complete, carefully check the PC board for any Fig.5: this diagram shows the details of the collision switch. solder bridges or dry joints, and check all components for correct placement and orientation. More construction detail The easiest way of working out the correct mounting of the motors will be through trial and error. First, wire them both up as shown, observing the correct polarity of the motors. That done, run the WALTZING-MATILDA DEMO. Immediately after the first line of “Waltzing Matilda”, the wheels should both roll so as to propel the robot forwards – then there should be a beep and only the left motor (viewed from the rear of the robot) should reverse. If the motors do not rotate as described, then re-orientate them so that they do. Once the drive motors have been fassiliconchip.com.au tened into place, the battery should be mounted on top of the platform – slightly back from the two drive shafts, so that the robot’s load is slightly to the rear of the platform. This gives it a good weight distribution and gives traction to the drive wheels, while not overburdening the rear swivel-wheel. Four corner brackets were used to hold the battery in place and a length of telephone wire (or a cable tie) can be used to tie it to the platform through drilled holes. The prototype used a rear swivel-wheel, and a 40mm diameter gear wheel was used for the wheel. A sturdy 130mm length of 2.5mm dia-meter steel wire, together with a metal bracket, was used to attach the wheel to the platform. Nuts were slipped over this wire and glued into place as shown, to hold the wire in the bracket, and to hold the wheel in place. It is important that this wheel should touch the ground at a point central to the other two wheels, otherwise the robot is likely to have a “lean” to it, and this is why the steel wire is curved as it is. Together with the other wheels, the swivel-wheel should also, at all times, provide a three-point base on which the robot may rest, so as not to tip over. Make sure that the swivel-wheel has the freedom to swivel through 360°. It should not, for instance, bump into the motors or the on-off switch, or be impeded by drooping wires. This robot has the potential for “wild” motion and could run into trouble if the swivel-wheel snags. Mounting the PC board The PC board is mounted on top of the platform at the back, behind the battery, with the jack socket facing the rear for easy insertion of the serial cable. For neatness, holes may be drilled in the platform beneath the PC board, so that sheathed wires may be run underneath the platform. In the prototype, the PC board was raised above the platform on bolts, which made the wiring easier, as well as making room for the piezo sounder and the screws used to secure the swivel-wheel assembly. A simple bumper bar is fixed to the front of the robot for the bumper switch S1. All that is required here is that S1’s contacts should close on collision. The siliconchip.com.au This underside view shows how the motor/gearbox assemblies are secured to two wooden rails using machine screws and nuts. Note also the rear swivel-wheel assembly. prototype used a brass strip that was “sprung” on two brass loops, making contact with a brass stub on the platform when a collision took place. Finally, switch S2, piezo sounder X1, and LDR1 are connected to the PC board. Switch S2 may be mounted on the hardboard platform. The piezo sounder may be fixed underneath the PC board with a little glue. A short tube (say 15mm in length) should be slipped over the LDR and this should be mounted on the front of the robot with a clear view in front. Without this “blinker” tube, the LDR does not have sufficient directionality to be of much use. Once the circuit is complete, piezo sounder X1 presents a quick and easy way of testing for life in the circuit. Using the WALTZING-MATILDA DEMO, only the piezo sounder and battery need to be wired up at first. Switch on the circuit, being vigilant for any sparks or abnormal heating! If the slightest problem should be sus- This close-up view shows how the LDR is housed in a short (15mm) length of tube. It sits just behind the collision switch. September 2004  69 Fig.6: follow this diagram to complete the wiring for the Robot. Power comes from a 6V 4Ah sealed lead acid battery which is mounted just behind the front axle assembly pected, switch off immediately and thoroughly re-check the PC board. Program the PICAXE-08 by means of the serial cable. This is done by opening the WALTZING-MATILDA DEMO file and then pressing F5. If the motors have been attached at this stage, the robot will wiggle briefly – then the first line of “Waltzing Matilda” will play, and the robot will drive forwards. Then it will turn and repeat the sequence. If the motors have not yet been attached, the sound of “Waltzing Matilda” will give confirmation that a good deal is already working well – the programming system, the serial cable, the PICAXE-08 IC and some of the surrounding components at the very least. To adjust the PICAXE-08 to the surrounding light level, run the LDR ADJUST program, and keep the serial cable connected while you do so. Adjust VR1 and as you do so, observe variable b3 on your computer screen. When the robot is aimed at the darkest areas of the room, b3 should read 160, while lighter areas should show lesser numbers. What is most important is that there should be maximum variation in this number (b3) as the robot surveys different areas of a room. Turning it loose! The PC board is elevated on its mounting bolts to allow the wiring to the motors, etc to pass through holes drilled through the baseboard beneath it. 70  Silicon Chip Once complete, place the Programmable Robot on a hard floor and switch on. All being well, it will wiggle, then follow the rest of its programmed behaviour. The best “general purpose” program is the LIGHT & BUMP DEMO. Place a lamp on the floor, switch off any other lights, and then switch on the robot – facing any direction at all. This demo never fails to impress, with the Programmable Robot heading for the SC light like a moth to the flame. siliconchip.com.au SILICON CHIP siliconchip.com.au YOUR DETAILS NEED PCBs? Order Form/Tax Invoice You can get the latest PCBs and micros direct from SILICON CHIP! See p100 for full details . . . 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SILICON CHIP MAGAZINE BINDERS q OR FAX (24/7) This form (or a photocopy) to (02) 9939 2648 with all details AMATEUR SCIENTIST CD NEWEST Version 4.0............................................. $62.00 AUDIO POWER AMPLIFIER DESIGN – SELF ................................................. $81.00 BUILD YOUR OWN ELECTRIC MOTORCYCLE ... ............................................ $40.00 DVD PLAYERS AND DRIVES ........................................................................ $71.00 ELECTRIC MOTORS AND DRIVES.................................................................. $51.00 NEWNES GUIDE TV & VIDEO TECHNOLOGY................................................. $49.00 OP AMPS FOR EVERYONE.......................................................................... $100. 00 PIC IN PRACTICE........................................................................................... $60.00 PIC MICROCONTROLLERS - KNOW IT ALL................................................. $83.00 PIC MICROCONTROLLER - PERSONAL INTRO COURSE............................... $60.00 PRACT. GUIDE TO SATELLITE TV (7th edition)............................................. $49.00 PRACTICAL RF HANDBOOK .......................................................................... $61.00 PRACT. VAR. SPEED DRIVES/POWER ELECT................................................. $73.00 PROG. 32-BIT MICROCONTROLLERS IN C ..................................................... $79.00 PROGRAMMING AND CUSTOMIZING THE PICAXE ................................... $65.00 RADIO, TV AND HOBBIES ON DVD-ROM ...................................................... $62.00 RF CIRCUIT DESIGN...................................................................................... $63.00 SELF ON AUDIO (2nd edition)........................................................................ $69.00 SMALL SIGNAL AUDIO DESIGN.................................................................... $88.00 SWITCH. POWER SUPPLIES A-Z (inc CD-ROM)............................................ $91.00 TV ACROSS AUSTRALIA ............SUPER SPECIAL – LAST FEW! $39.95...... $29.95 USING UBUNTU LINUX.................................................................................. $27.00 P&P RATES: Many PCBs and panels, along with some pre-programmed microprocessors and microcontrollers are now available direct from SILICON CHIP. See the separate page listing those currently available on page 100. To eMAIL (24/7) Place silicon<at>siliconchip.com.au Your with order & credit card details Order: siliconchip.com.au AC MACHINES................................................................................................ $66.00 Subscriptions, back issues and project reprints: P&P included Binders (available Australia only): $10.00 per order; for 5 or more P&P is free. Books: Aust. $10 per order; NZ: $AU12 per book; Elsewhere $AU18 per book OR PAYPAL (24/7) OR Use PayPal to pay silicon<at>siliconchip.com.au PHONE – (9-5, Mon-Fri) Call (02) 9939 3295 with your credit card details OR MAIL This form to PO Box 139, Collaroy NSW 2097 September 2004  71 *ALL ITEMS SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES IN AUSTRALIAN DOLLARS AND INCLUDE GST WHERE APPLICABLE. 9/04 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/ Oh no! Not Another CFL Inverter . . . Design by BRANKO JUSTIC Words by STEPHEN DAVID Yes, another one. But they just keep getting better and better! This highly efficient 12V DC-DC converter runs multiple compact fluorescent lights (CFL) for use in recreational vehicles, camp-sites, remote homesteads or anywhere remote when you need efficient lighting. As a bonus, it can even run a small colour TV set. T his one’s a beauty. It will drive multiple CFLs without the need for heatsinks on the MOSFETs. Fit heatsinks and you can run even more, up to a total of 100W. However, the real bonus is that you don’t have to wind the transformer – a tricky job at the best of times. This kit comes with a pre-wound transformer so all you have to do is to solder it into the PC board. As pictured, the prototype inverter is running four 11W CFL tubes and the MOSFETs are barely warm. And to do that it is drawing just 3.2A from a 12V battery so it is a pretty efficient device. It’s compact too, housed on a PC board measuring 83 x 50mm and 76  Silicon Chip standing about 58mm high because of the on-board transformer. The circuit is quite simple, as shown in Fig.1 and is based on an ST SG3525 regulating pulse-width modulator (IC1) which drives a couple of Mosfets and CAUTION: DANGEROUS VOLTAGES The output from this inverter is around 350V DC and is thus as dangerous as mains voltages. Handle with care – never work on the circuit with power applied. The finished project should be installed in a plastic case. the push-pull stepup transformer. The on-chip oscillator is set by the 4.7nF (.0047mF) capacitor at pin 5 and the 3.3kW resistor at pin 6, giving a frequency of about 85kHz. This is divided by two by an internal flipflop and the flipflop’s complementary outputs drive buffers which can source or sink in excess of 200mA. The buffer outputs at pin 11 & 14 drive two MOSFETs, Q1 and Q2, with the high output current capability being ideal for rapid charge and discharge of the MOSFET gate capacitances, resulting in fast switching times. This results in high efficiency and little power loss in the MOSFETs. The MOSFETs drive the push-pull step-up transformer. This has four turns on the two primaries and 120 turns on the secondary, giving a stepup ratio of 30 times. The transformer is connected to a bridge rectifier consiliconchip.com.au Fig.1: an SG 3525 pulse width modulator chip running at 85kHz drives two MOSFETs and a stepup transformer to develop 350V DC to drive compact fluorescent lamps (CFLs) or a small colour TV set. sisting of four BA159 1A high speed diodes and a filter capacitor of a mere 1nF (.001mF). The resulting DC voltage is about 350V. The output voltage is not regulated unless it exceeds 370V, as set by the resistive feedback network (220kW, 270kW, 6.8kW) connected to pin 1, the inverting input of the internal error amplifier. This samples the output voltage and compares it to a 5.1V internal reference (pin 16) connected to pin 2, the non-inverting input of the same internal error amplifier. The reason for not regulating the output voltage to a lower value is to avoid reducing the efficiency of the converter. In any case, regulation is not necessary in this application because CFLs can operate over a wide voltage range with a little variation in light output. The 68nF capacitor at pin 9 provides a “soft start” facility. The capacitor is charged by a 50mA constant current source inside IC1 and this causes the duty cycle of the output signal from pins 11 and 14 to slowly rise from zero to 50%. The soft start is needed because of the relatively large filter capacitor in an electronic ballast or a CFL. Under-voltage protection is provided by the SG3525 by virtue of the fact that it will stop operating below 8.5V. This avoids the possibility of inadequate gate drive to the MOSFETS siliconchip.com.au which would lead to over-dissipation. However, note that this does not protect any SLA battery from overdischarge. Construction Assembly of the PC board is pretty straightforward as there is only a handful of components. The component layout is shown in Fig.2. Mount the resistors and diodes first, making sure that you install the diodes the right way around. Then mount the small capacitors and the electrolytic which must have the correct polarity. The transformer can be soldered in next. Its leads are already soldered to pins, so it simply drops into the appropriate place on the PC board. It’s efficient and it’s easy to build, thanks in large part to the pre-assembled transformer. Watch the polarity on the semiconductors and electro. September 2004  77 Then install the two MOSFETs and a socket for IC1. When you insert the IC into the socket, make absolutely sure you install it the correct way around (otherwise smoke will escape when you turn it on!). For up to (say) 50W output (4x 11W CFLs), MOSFET heatsinks aren’t needed. Higher output (such as driving the TV set below) will need small heatsinks on each of the MOSFETs. Fit four PC pins for the external connections and then you attach the leads for the battery and the output socket (or sockets). Carefully check your work and then connect one CFL to its socket. Then connect the 12V battery. The CFL tube should light instantly. If not, turn off and carefully re-check your work (which you should have done before!) Note that while the output of the inverter is polarised, it does not matter which way around a CFL is connected as its electronics contains a bridge rectifier. SC Fig.2: component overlay for the PC board. Kit availability A kit of parts for this project, including the prewound transformer, is available from Oatley Electronics, for $24 including GST (Cat K111A). Postage and packing is $8 for up to eight kits. Contact Oatley at PO Box 89, Oatley, NSW 2223. Phone (02) 9584 3563. email sales<at>oatleyelectronics.com; web: www.oatleye.com Operating a colour TV from the inverter As part of the development of this kit, Oatley Electronics (who own the design copyright) have used this circuit to run a 240VAC 30cm colour TV, as seen below. This “Prima” brand set was purchased at a supermarket for only $99 (truly!), much cheaper than an equivalent 12V TV. Therefore it makes sense to use this circuit with a 240VAC small colour TV, doesn’t it? Don’t attempt to do this, however, if you are not experienced with switch-mode supplies and TV set circuitry in general. The only proviso is that the TV’s degaussing coil must be disconnected because it is important that it The CFL inverter board mounted on the inside of the TV set case via cable ties (the other board you can see is part of the tube drive). It connects to the TV’s main PC board at the same place as the normal mains input connects, taking advantage of the fact that the switch-mode supply immediately rectifies the 240V AC mains (to about 350V DC). NEVER run the TV set from the mains and the inverter at the same time. And note our comments about disconnecting the degaussing circuit. does not get the 350V DC from the CFL driver circuit. Then from time to time (especially if the TV is moved), the degaussing circuit will have to be reconnected and the set temporarily run from 240VAC to make sure the picture tube is degaussed, otherwise the tube will develop purity problems. Oatley Electronics are currently developing a 12V Degausser which should be ideal for use with this setup. More details when they become available! 78  Silicon Chip siliconchip.com.au NEW 6VDC LUXEON LED DRIVER KIT This kit is designed to drive 1-3W from 4-6V, usable down to 3V! Shown actual size $5.90 . (K216) PICAXE-08M MICROCONTROLLER CHIP This is the new version that has in-built tunes. $4.70 Check our web site for more PICAXE chips. (USED) 32MB SDRAM MEMORY (168 PIN): Bring that old second PC back to life for a small outlay. We have a good but limited quantity of this memory $11 or 4 for $30 (M32MB) (NEW) 30W GENERAL PURPOSE SOLDERING IRON: Duramax brand. 30 Watt 240V soldering iron. Ideal for the home workshop. Replaceable tip. Free solder. $15 (SOIRON) (NEW) 8 IN 1 UNIVERSAL REMOTE CONTROL: Replace lost or broken remote controls, and suits most brands. Operate your TV, VCR, Cable, CD, VCD, DVD and other Audio products with a single remote control. Requires two AAA size batteries (not included). $19 (R8IN1) SOLID STATE RELAY: Mitsubishi type SFD20D9121 20A-240V Solid State Relays, operate from 4-7VDC or higher DC voltage if a series resistor is added, would need extra heat sinking if used at currents over a few amperes, have TUV, SA and RU approvals. $11 or 3 for $27 (SSR1) (NEW) PACKARD BELL FAST MEDIA REMOTE CONTROL: Easy to access your computer's multimedia applications (e.g. Winamp, Windows Media Player, Win DVD etc.) from a distance. Control your keyboard, mouse; & most applications. Uses DB9 serial port. MS Windows 3.1 & above. Inc. Remote, 1x Receiver w/ DB-9 connector, & manual. Req. 2x AA Batt. (not supplied) & free software download. $24 (RC11) (NEW) FM RADIO: Frequency Range: FM88 - 108MHz. Requires two AA size batteries (included). $4.20 (LEMON) (USED) 150W POWER SUPPLY: FDK Brand, model # PEX668-31. Has 2 internal 60mm fans and two STD IEC mains connectors (1x NOTE: for Male and 1x Female). experienced Input: 100-240VAC <at> hobbyists only!!! 6.6A 47-63 Hz. Output: $12 +5VDC <at> 25A, +12VDC <at> 2.3A (Max. 4A), -12VDC <at> 0.25A. Outlet: 100-240VAC <at> 4A 47-63 Hz. Total Max. continuous: 150.2W. Total Max. out: <15 Sec.: 174.2W. 2 or more could be connected in series & modified for other voltages. (SUNPSU) (USED) SUN MICRO POWER SUPPLY: Sun Microsystem Brand, model # PEX736-30. Used but are in excellent condition. Input: 100240VAC <at> 0.7A 50/60Hz. Output: +5VDC <at> 5A, +12V <at> 0.4A. IEC input AC connector, 5ft output cord with 8 PIN mini DIN connector Weight: 0.7kg. $12 (SUNPSU2) (USED) 2.1GB 5400RPM 80-PIN SCSI HARD DRIVE: We have a quantity of Seagate ST32430WC (2.1GB) 3 1/2" 5400 RPM Single Ended Fast/Wide SCSI 80-PIN and IBM DORS-32160 2.1GB 3 1/2" 5400 RPM Single Ended Fast/Wide SCSI 80PIN hard drives. We can't pick and choose what variety you will get so please do not ask, but if you order more than one we will try to ensure that you get drives that are all of the same variety. $22 (SUNHD) POWERFUL DC MOTORS / GENERATORS: The 200W motors are the same as used in our scooters. They are very powerful for there size, built for 24V use, but produce lots of torque at 12V. They start rotating at only 0.5VDC. These motors make great generators . When driven at a low speed with a cordless drill they produced 6V open circuit, 5V <at> 5A & 4V <at> 8A; Very reasonable freight costs to most Australian capitals. (NEW) 100W DC MOTOR: 100W output as used in our small scooter. 24VDC. Rated speed: 2300 RPM Rated current: 6.0A Measures: 67mm X 97mm (+ shaft) Shaft: 8mm "D" shaped end with cir-clip groove. Weight: Approx. 1.1kg. $22 (SC100) (NEW) DC MOTORS: 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 treaded 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) 300W 24VDC, 16.4A, 2650 RPM, $36 (SC300) 100W SCOOTER REAR DRIVE PARTS ASSEMBLY These are the drive components from our 100W scooter including the motor, toothed belt, pullies, rear wheel, brake assy. and ONLY $32 throttle assemblies. Ideal for robotics projects and electric vehicles etc(SCD2) $32 (NEW) 12V / 24V CHARGERS: These chargers charge at a fast rate reducing the current with the rise in charge but should not be left indefinitely. Charging figures from a quick test were 2.5A charge <at> 11V, 2A charge <at> 12.4V and 0.4A charge <at> 14.9V. 12VDC CHARGER: 240VAC - 12VDC <at> 2300mA: (SCC12) $17 24VDC CHARGER: 240VAC - 24VDC <at> 1300mA: (SCC24) $17 PB12 (NEW) 12V / 12AH GELL CELL BATTERY: Measuring 150mm L X 94mm H X 95mm W and weigh approx. 4100g. If you are looking for a charger check out our (SCC12) and (SCC24) mains powered chargers. SPEED CONTROLLERS Speed controller modules for the 24V motors we stock. They come with a diagram. These units require a 4K7 or 5K pot & a 2k7 resistor (not supplied) to replace the original throttle. CONTROLLER (SPC150) UP TO 150W/24V MOTORS: $14 CONTROLLER (SPC350) UP TO 350W/24V MOTORS: $24 SUPER PRICES ON NEW UHF MODULES Cheap home automation with these new miniature UHF modules. Band width limited to 1.2kbs. (TX434) $9 (RX434LC)$9 NEW ELECTRIC GOLF TROLLEY Don't Pay well over $1000 With a150 Watt Electric Motor and 12V/17aH battery Folds away for transthis trolley will travel a port or storage. distance of 18-20km ONLY $450 REDUCED PELTIER DEVICE PRICES!!! Dim: 40 x 40 x 4mm. GP1 4.0A Device / D T 65° / Qmax 42W, $10 GP2 6.0A Device / D T 65° / Qmax 60W: $13 GP3 8.0A Device / D T 65° / Qmax 75W: $16 AMAZING WIND GENERATORS AT CRAZY PRICES These are serious 3 phase 200W wind generators with blades spanning 2.2M and come with 5.5M mast with guy wires. They are designed to start operating in low air speeds (around 11kph) while being robust enough to withstand strong gales. They are rated at 200W <at> 21kph with a max of 250W. With a commutator (slip rings) built in. These generators output 3 phase (sine) and our optional new high current 3 phase rectifier and charger kits will enable you to charge a bank of batteries. (WG1) CTORY TRODU CRAZY IN F ONLY $699 PRICE O NEW ELECTRIC BIKE Size: 1130 x 390 x 1000mm Brake: hand brake, rear wheel drum brake. Battery capacity: 12AH, 36V. Battery charger: 240V Motor power: 200W. Charging period: 4-5 hours. Speed: 20km/h. Range: 15km. Wheels: inflatable. Frame: painted steel. Weight: 21kg. Maximum load: 100kg. Forget waiting for trains and busses that don't come, the regulations on the NSW RTA web site indicate that they cab be ridden under the same rules as a bicycle. Come complete with batteries, lights and charger. $300 (SC3) COMPUTER MONITOR GLASS FILTERS These Focus-opti-Plus computer monitor glass filters are made in Denmark. They come complete with universal mountings and earth connection. They reduce glare by up to 99%, improve readability, minimise eyestrain and reduce UVA / UVB and E-field emission by up to 99%, easy to install. Brand new in original packaging & at a price which saves up to over 80% on their actual value: $15 Ea. Chose from 14-15", 16-17", 19-21" (CM14, CM16, CM19) LY N O 00 $3 COMING SOON 30mW+ GREEN LASER HEADS. Requires a constant current source only, typical 500mA<at>1.8V DANGER!!! For experienced laser users only LOW INTRODUCTORY PRICE $350!!! Also coming. complete laser light show kit using these laser heads. ELECTRIC BIKES/SCOOTERS (SC1) ELECTRIC SCOOTER Unlike some others these have Australian approvals L inc."C" TICK. (SC1). This CIA E P portable light weight scooter S W NE CE folds up for easy carrying & I R storage. Features include P 79 $ variable speed control, hand lever style brake. Brake & throttle can be swapped from side to side. Telescopic handlebars. Complete with mains charger & batteries. Speed: 12km/h, Motor: 100W, Battery: 12V x 2, 4.5A, Range: ~14km, G.W: 10kgs N.W: 8kgs Meas: 740X130 (deck) x 930mm. NOTE: These scooters are not toys & should only be used under competent supervision & only where allowed by local authorities. 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 Box 89 Oatley NSW 2223 OR www.oatleye.com major credit cards accepted, Post & Pack typically $7 Prices subject to change without notice ACN 068 740 081 ABN18068 740 081 SC_SEP_04 Vintage Radio By RODNEY CHAMPNESS, VK3UG This Little Nipper was a dog HMV’s “Little Nipper” was usually a reliable and pleasant companion. However, I recently had to restore one that was a real “dog’s breakfast”. H MV used the name “Little Nipper” for a popular line of mantel receivers made from the 1940s through to the 1960s - just as Astor used the name “Mickey” for some of its receivers. The line-up included many different models in various formats, including the 62-52 unit featured here. Basically, the “Little Nipper” receivers came with either four or five valves and were usually broadcast band receivers only. However, some dual-wave sets also carried the “Little Nipper” name. These sets were all “middle-of-theroad” in terms of quality, with good performance and an attractive appearance. The various designs were well thought out and they were generally easy to work on. Naturally, the circuit designs and the appearance evolved as time went by. The cabinets changed too, progressing from bakelite to plastic in the later years. Restoring A 62-52 A rather sad looking Model 62-52 Little Nipper was recently brought to me for servicing. The owner didn’t want me to do a complete restoration. Instead, he would restore the cabinet This view shows the Little Nipper receiver as it landed on my workbench. It was dirty and fitted with the wrong knobs – and that was just the outside. 80  Silicon Chip The original knobs fitted to the “Little Nipper” had a tendency to break in the centre. and find suitable knobs himself (the original knobs were either broken or missing). Unfortunately, the correct knobs for these sets are rather hard to come by and I had none spare. In use, they often break in the centre but they can be repaired using Araldite or a similar epoxy adhesive. If any of the plastic that normally surrounds the shaft is left, a greased short length of shaft from an old control can be sat in the shaft groove. The trick is to make sure it is vertical (as it would have been originally) and before sitting the shaft in place, score the plastic on the underside of the knob to give the Araldite something to adhere to. Most of the underside of the control can then be filled with Araldite and allowed to set. The shaft can then be removed after the Araldite has set, as the grease prevents it from adhering to the shaft. The repaired knob will work as good as new and will be stronger than before. To give even greater strength, a small key ring can be slightly spread and slid over the end of the knob’s shaft. However, this will not be possible with siliconchip.com.au the knobs from some sets, as the hole through the receiver’s escutcheon may only be slightly bigger than the knob’s shaft extension. If necessary, the split control shafts can be spread slightly so that the knobs are a firm fit and remain in place. The process of repairing the knob can be seen in the accompanying photos. Fortunately, this particular set hadn’t had a rough life, with the knobs being the only obvious casualties over its lifetime. The cabinet was given a quick clean-up to make it a little more presentable and to make the set more pleasant to work on but it certainly wasn’t a full restoration. Getting it working According to the owner, the set wasn’t working because the power transformer had “burnt out”. I had one spare, so if that was all that was wrong with it, getting it working again would not be difficult. Fig.1 shows the circuit details of the set. Note, however, that this is actually the circuit for a 61-51 but it’s virtually identical to the 62-52. Because there was no smell of burnt insulation, I wondered if the transformer really had failed.” As a result, my first step was to test the transformer for any insulation breakdown using a 1000V insulation tester. This showed that there was a least 200MΩ of resistance between each of the three windings and transformer frame. The only other thing likely was shorted turns in one of the windings. To check this, the rectifier was first removed and the set connected to power and switched on. The voltage between each end of the high-voltage winding and earth was then measured. They were within a volt or two of each other at around 350VAC, which is to be expected with no load. This meant that the high-voltage secondary winding was probably OK. In addition, the dial lamps were alight and the voltage across the filament line was around 6.8V, which was quite reasonable as both secondary windings were lightly loaded. What if the primary had shorted turns? In that case, the secondary voltages would probably have been higher than they were. In addition, the smell of burning insulation would have been evident and the transformer would probably have been making a siliconchip.com.au The layout on the top of the chassis is uncluttered, so access to individual parts is easy. It’s just as well, because this set had more faults than you could imagine. This is the under-chassis view before restoration. The 2-core mains flex was later replaced with a 3-core cord, so that the chassis could be earthed. “fizzing” noise. There may even be wisps of smoke but none of these symptoms was evident. As a result, I left the set run like this for several minutes and the transformer showed absolutely no sign of heating. It just went about its job with no fuss, so all was apparently well. It was at this point that one of the dial lamps suddenly decided to go out. It was easily fixed – the lamp had come loose in its socket and tightening it immediately fixed this intermittent fault. Finding an HT short It was now time to look further into the set and try to discover why the owner thought that the transformer had burnt out. My first step here was to switch the set off and check the resistance of the HT line to earth – it measured just 80Ω which, for all practical purposes, is nearly a dead short! I then checked electrolytic capacitor C21 on the output of the rectifier but it was OK, so I set about isolating everything at that point (with the rectifier still removed). It didn’t take long to discover the problem – when I lifted the speaker transformer clear of the chassis, the short disappeared. A quick check with a multimeter showed that it had a low-resistance short from its primary winding to the frame. So this was the “burnt out” transformer. Obviously, a replacement transformer was needed, so I rummaged through my collection of speaker transformers. September 2004  81 The Araldite is “poured” into the underside of the control knob, while the keyring prevents the centre boss from breaking again. The control knobs can usually be repaired using Araldite (or a similar epoxy adhesive), a small key ring and a scrounged (greased) control shaft. The control shaft is removed after the Araldite has set. Unfortunately, I couldn’t find one with a 7000Ω to 3.5Ω impedance ratio that was small enough to fit into the available space. In the end, I used a transformer with a 5000Ω to 3.5Ω impedance ratio and installed a small resistance in series with the secondary. This gave an ideal match to the audio output stage, although the total audio output to the speaker would be reduced by a few percent. By the way, please note that for safety reasons, all sets should be switched off and the power lead removed from the power point before doing any work on the circuitry; eg, soldering or desoldering leads, etc. Disintegrating valve socket During the course of my investiga- tions, the four leads from of the speaker transformer had to be disconnected (by desoldering them). Three came off as expected but the fourth which went to the plate of the 6M5 valve just came out of the socket. In fact, the whole wafer socket just disintegrated, which is something I haven’t seen before. This meant that before I could wire in the new transformer, I had to replace the valve socket. To avoid errors later on, I drew a diagram of the wiring before removing the wrecked socket by drilling out its retaining rivets and replacing it with a moulded insulation type. The only problem was that when I went to fit the new socket, I found that the mounting holes were in different positions relative to the valve pins as compared to the previous socket. These are just some of the parts that were replaced in the set. It’s a good idea to replace paper capacitors as a matter of course. 82  Silicon Chip This problem was solved by cleaning the chassis and then soldering the mounting lugs in the new position, so that the socket pins were in the same place as before. The leads from the valve were then resoldered to the socket except that I made one small modification. Originally, pin 6 of the 6M5 was connected to chassis. This pin is shown as an “Internal Connection” in the valve data books, which means that it may be used as a support for various elements within the valve. As a result, it should be left free even though nothing was connected to it with this particular 6M5. A replacement valve might have something connected to it, however – such as the plate! Testing resistors & capacitors With all this completed, it was now time to test the audio coupling and AGC capacitors. The audio coupler (C18) from the plate of the 6AV6 to the grid of the 6M5 had no measurable leakage but someone had previously replaced it with one a tenth of the correct value. This was replaced, as were audio coupler C16 and the two AGC capacitors (C3 and C9), which were all leaky. Note that in this circuit, C9 must be replaced with the same value, as it is part of a bridge neutralisation circuit in the intermediate frequency (IF) amplifier. Moving on to the resistors, R7, R8, R9 and R13 had all gone high and were way out of tolerance. They were also replaced, so what was originally supposed to be a simple servicing job was becoming quite involved. And I still hadn’t even turned it on with siliconchip.com.au the rectifier in place to see how it was going! Switching on Fig.1: the “Little Nipper” is a fairly conventional 5-valve superhet. It was time for the smoke test but before switching on, I removed the 6M5 and inserted the 6X4 rectifier into its socket. That done, I checked for a short-circuit between the HT line and earth. This was necessary because it was possible for the 6X4 to have a filament to cathode short after being subjected to output transformer short circuit. There was no short with the valve cold, so I gingerly turned the set on and checked the voltages in the set. The DC voltages all came up as they should and the 6X4 was apparently none the worse for the savage overload it had experienced. By the way, early 6M5 valves experienced silver migration between pins 1 and 2 of the valve after some use, which causes a positive voltage to appear on the grid. To overcome this, I lightly scored the glass with a sharp scriber between these two pins to break up any silver film between them (in fact, I always do this whether there is a problem or not). That done, I plugged the 6M5 valve into its socket but there were immediate problems. The set came on with a howl and was whistling, even with the volume control turned down. The whistling 6M5 So what was wrong? The output stage (6M5) has negative feedback applied from the secondary of the speaker transformer via C22. Of course, it is necessary to wire the transformer so that the feedback is negative but I’d managed to get positive feedback! This was easily fixed - all I had to do was swap the two leads on the secondary of the transformer. That done, the audio amplifier stage was stable, although it appeared to have some hum. And it still had annoying crackles and some hiss (but no stations) when the volume control was turned up. I tried moving the valves in their sockets and this made the crackling worse so it appeared that the socket contacts were causing problems. It was time to turn the set off and clean and tighten the valve socket pins. The pins were cleaned with “Inox” lubricant, after which a sharp “modified” screwdriver was pushed in siliconchip.com.au alongside each socket pin and the two sides levered closer together. The valves were then re-inserted and the set turned on again. That stopped the valves from making extra noises when they were moved but it wasn’t the complete cure - the set was still full of “crackles”. I then tried tapping around various parts of the set with the plastic handle of a small screwdriver and this caused the crackling to vary in intensity, espeSeptember 2004  83 Photo Gallery: 1933 Essenay M447 Produced by the Essenay Manufacturing Company Pty Ltd in 1933, this compact wooden receiver was fitted with five valves and tuned the medium-wave broadcast band. A feature of the cabinet was the ornate speaker opening and the “peep-hole” dial. The valve line-up was 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. cially when I tapped around the first IF transformer. Fun in the IF amplifier To diagnose this problem, I first fed a high-level tone-modulated 455kHz signal into the antenna terminal. This gave some output from the speaker, which varied with the tapping. Using a digital multimeter, I then measured the voltage across C9 and initially it was negative. However, after running the set for a few minutes, it gradually increased to 0V and then started to climb in a positive direction. During this time, the output variations seemed to remain consistent and the output from the detector was still negative. Thinking that there must be some leakage resistance between the two windings in the IF transformer which occurred as the set warmed up, I disconnected the secondary winding and checked for leakage using a highvoltage tester. However, even with 84  Silicon Chip the high-voltage tester applying 500V between the two windings, no measurable resistance was observed. With the transformer rewired into circuit, my next step was to check the valve itself. A new 6BA6 was fitted and that fixed the positive grid voltage problem, so the original 6BA6 was faulty (gassy maybe?). The IF amplifier was now amplifying as it should but the crackling was still quite evident. A new 6BE6 frequency changer enabled the set to now tune stations. However, it didn’t fix the crackling and the set would even occasionally “jump” off station. I initially thought that this might be due to poor contacts between the moving surfaces of the tuning gang, thus causing the frequency to jump. Unfortunately, lubricating these made no difference so I checked to see if the gang plates were shorting. At first glance, they didn’t appear to be, so I put a strong light in line with the tuning gang vanes and looked through the gangs from the other side. This showed that two plates were probably shorting so I carefully bent one away from its neighbour which gave some improvement. Closer inspection then revealed that some of the other plates were close (perhaps too close) to their neighbours as well. To check this, I disconnected the tuning gang from all other parts of the circuit (including the trimmer capacitors) and connected a highvoltage tester set to the 1000V volt range across each gang section in turn and rotated the tuning shaft. As I rotated the shaft, there were occasional “flickers” in the reading, indicating where the shorts were. A little more judicious bending of the plates finally cured the crackles problem once and for all. However, that wasn’t the end of the story as the frequency jump problem was still occurring. I’d checked all the soldered joints and the moving points on the tuning gang and all appeared to be in good order, so the problem wasn’t here. I even swapped the 6BE6 but it made no difference, so I took a close look at the oscillator circuit. Sleuthing the oscillator It was about this time that the crackles also reappeared. Obviously, there was a problem with the oscillator circuit but which component could be causing it? L3, C4 and TC2/VC2 are all frequency determining components, so this was they obvious place to start. TC2 and VC2 had been previously attended to, so I assumed they were OK. C4, however, consisted of two mica capacitors in parallel, one a much larger than the other. Perhaps the low value one was intermittently going open circuit, thus causing the oscillator to change frequency? I removed the capacitor and checked it using both a capacitance meter and the high-voltage tester but it checked OK. In addition, a substitute capacitor made no difference, so padder capacitor C4 was OK. So much for that theory! Coil L3 was my next suspect – perhaps it had an intermittent 1-turn short circuit in the winding? A multimeter test was inconclusive but pulling the coil out, I decided to check R2 and C5. These components are not part of the tuned circuit but they do have an effect on the oscillator siliconchip.com.au frequency to a small degree. R2 was in tolerance and even with the multimeter and showed no variation in resistance over time. Similarly, C5 tested OK for capacitance (50pF) and no leakage resistance was detected using a digital multimeter. However, C5 was a different story when tested on the 500V range of the high voltage tester. This showed a leakage resistance of about one megohm , with the meter needle regularly flickering slightly. Eureka! - the rotten little beast tested OK on all bar the high voltage tester, so you can understand why I consider this an essential item of test equipment. I have had very few faulty mica capacitors in receivers but when they do become faulty, some weird symptoms can appear. A noisy oscillator, as in this case, can give some very misleading symptoms. Alignment Having cured the circuit faults, the next step was to align the IF amplifier, antenna and oscillator circuits. This was done using a signal generator and this showed that the IF amplifier was well out of alignment. It responded well to adjustment but in the course of endeavouring to lock one of the cores with core-locking compound, it shattered at the end of the adjustment slot. As a result, the alignment was completed with one core slightly out of tune. Despite all my “playing around” with the oscillator circuit, it was almost perfectly aligned, with the stations appearing on the correct spots. Well at least something went right with the overhaul! Improving the hum From the very beginning, this set had exhibited a background hum, even with the volume control turned right down. My first suspects were filter capacitors C17 and C21 in the power supply. They were both down slightly at 14µF but not enough to warrant replacement. However, I found that I could reduce the background hum by paralleling these two capacitors with similar values. The real cure lay in modifying the plate circuit of the 6AV6. This was made similar to other many older receivers by adding a 33kΩ resistor in series with the bottom end of R8 and installing a 1µF 350V electrolytic siliconchip.com.au capacitor from the junction of these two resistors to earth. This simple modification cleared the hum up nicely. It appears that the ripple filtering circuitry in many later receivers was the minimum that manufacturers thought that they could get away with. A microphonic valve The “Little Nipper” receiver was now running quite well. It was sensitive, stable, the audio sounded good and there was virtually no hum. As a final check, I decided to test the valves by gently tapping them with the plastic handle of a small screwdriver. All went well until I tapped the 6AV6, which then squealed and crackled. This is not an uncommon fault in valves. In this case, one of the grid welds had probably come loose, causing the valve to become very microphonic. What’s more, as the grid wire scratched against the failed weld, it became “crackly” as well. A new valve soon fixed the problem. Power lead Before starting work on this set, I had attached an earthed lead to the chassis as a safety measure (eg, in case the power transformer developed a short to chassis). With the restoration work now completed, the final job was to fit a 3-core power lead, since there’s no longer a risk of it getting marked on a dirty work bench. A 3-metre 3-core extension lead can be used as the new lead. These extension leads can be obtained for around $3-4. You simply cut off the socket and wire the lead into the set. Note that the power leads in most radios from the valve era were knotted where they left the chassis, to prevent the cord from being pulled out. Today the lead should be clamped into position, for legal and safety reasons. An even cheaper proposition than using a modified extension lead, is to scrounge a lead from a defunct electrical appliance (provided it is in good condition). Of course, if you keep a clean workbench, the cord can be replaced at the start of the restoration. Summary The “Little Nipper” 62-52 is a typical 5-valve mantel set from the 1950s and 1960s. It is easy to work on, is a good performer and generally gives little trouble. 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 However, there is the occasional set from any make that proves to be a real “dog” and it requires all the restorers knowledge and patience to get it working properly. A set like this one will be a severe test for a newcomer to electronic restoration. The important thing is not to go “bush-ranging” through a set, replacing parts willy-nilly, as the results are usually disappointing. Don’t give up and if possible enlist the aid of someone more experienced than yourself if you get a “dog” like this one. That way, SC you can share the headache! September 2004  85 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 50MHz frequency meter display freezes I have recently built the 50MHz Frequency Meter (SILICON CHIP, October 2003) from a Dick Smith kit and have two problems. (1) Initially the LCD froze and would only display a dash and I had to reduce the supply voltage from +5V to +4V to get the display to work. What has happened here? (2) After power-up the LCD appears locked on “1Hz” and adjusting VR1 with the input shorted does not make it show “0Hz”. The meter does not respond to an input signal. I can trace an input signal to pin 4 of IC1 but pin 5 does not show any signal, just +2.8V DC. How do I troubleshoot this problem? At Royal Prince Alfred Hospital we have a Cyclotron that uses 11kW of RF power at 27MHz. I am hoping to fit a small antenna to this frequency meter and use it to show when RF power is “live”. Any advice to get it going would be much appreciated. Congratulations on an excellent magazine with the best DIY projects. (R. F., Camperdown, NSW). • Freezing of the display can be cured by changing the 470pF capacitor at pin 6 to ground on the LCD to a 2.2nF capacitor (code 2n2 or 222). The 10116 (IC1) needs a 5V supply and so its operation should be restored when you increase the supply back to 5V. A sniffer coil made up of 20-30 turns about 10mm in diameter can be used to detect the RF signal. Connect the coil to the frequency meter input via screened cable (75Ω TV coax would be suitable). Fooling the car’s ECU What do you think about the IAT resistors you can put in your car’s air inlet manifold? Are they rubbish or a worthwhile investment? They are claimed to trick your engine into thinking it is under a heavier load, therefore more BHP and torque will result as it opens the injectors slightly more. Are there any known problems you know of? (A. M., Adelaide, SA.) • IAT stands for intake air temperature and the IAT sensor is a thermistor which drops its resistance as the air temperature goes up. If you substitute or add resistors to the IAT sensor, it will trick your car’s ECU into thinking that the air temperature is warmer than it is. Depending on the actual engine load and temperature this might not be good at all. We wouldn’t do it without a lot more research. Troubleshooting a speed controller About one year ago I built the Universal Motor Speed Controller (SILICON CHIP, September 1992) and it worked well. It was particularly useful with things like angle grinders when used with a wire brush. At the unregulated speed it throws out small pieces of wire from the brush that can really hurt! Recently I went to use it and the fuse was blown and it blows any 10A replacement fuse that I put in it. I don’t know what could be wrong and I don’t want to replace parts one at a time, particularly as the project involves 240VAC. I have checked the wiring for shorted leads. Where do I start? (P. B., via email). • It seems likely that diode D3 has blown. Check with your multimeter to see if it is a short circuit in both directions. There is also a chance that the Triac has blown too. Again, check it with your multimeter between its A2 and A1 terminals. If they’ve both failed, it’s possible they have also Remote Control Extender Questions I’ve recently purchased a Remote Control Extender kit (SILICON CHIP, July 1996) and was wondering if the following is possible. I would like to hook up two or three separate rooms to be able to receive remote control signals and have the transmitted signal sent back to a single destination using the one kit (if possible). I’ve searched your site and noticed people asking for multiple IR transmitters (IR LED1) but not multiple IR receivers (IC1). I was thinking I could house the PC board main unit near the receiving devices (VCR/DVD and 86  Silicon Chip A/V receiver) and use a single 9V DC power supply to drive the multiple IR receivers (IC1) rather than having to plug in up to three separate power supplies with three separate kits. I was thinking I could do this by running three wires (using Cat 5e) in series to each of the IR receiver positions in the rooms but have no idea about the resistors, etc needed. Alternatively, if I used four wires, I could possibly accompany each of the IR receivers with its own acknowledge LED. Please let me know if this is pos- sible and how I could achieve it. (P. R., via email). • There is no reason why three IR receivers (IC1) cannot be paralleled, with the outputs connected together. The outputs are essentially open-collectors requiring a pull-up resistor. In the circuit, they use a 1kΩ resistor in series with a LED. So use the one IR extender and add in two more IR receivers by paralleling the positive supply, 0V and outputs. Note that each external IR detector would need a 10µF electrolytic capacitor across its power supply. siliconchip.com.au taken out the SBS (Silicon Bilateral Switch). By the way, angle grinders should not be used with wire brushes – they run much too fast, as you have found. USB Ports For Older Computers A friend and I have several older computers with USB header pin connectors on the motherboards. We wish to be able to hook up USB ports onto these computers but lack wiring diagrams for the motherboards. We wonder if you could design a device to plug into the USB port to test that the port is wired correctly and working. The device would need to be undamaged by an incorrectly wired port and be incapable of damaging the motherboard if the port is incorrectly wired. I would imagine that a hardware/software solution would be needed, as a hardware only solution probably isn’t possible. We realise that the simple solution is to purchase USB2 cards but Digital speedo wanted Is it possible to alter the Car Speed Alarm so it works as a stand-alone digital speedo? I realise we need to keep the Cal. mode but how do I remove the alarm section so it will still work? (R. N., via email). • As it stands, the Speed Alert can be used as a speedometer since it has this function. The alarm can be disabled simply by setting the alarm speed at the maximum setting. Wrong rails from bench power supply kit What is the cause of this problem? (S. C., via email). • You have an unusual problem with your power supply, if only those two 9:51 am Page 1 voltages are incorrect. We haven’t heard of that one before and it’s hard to suggest what could be wrong. All we can suggest is that you may Au V st is ro it N nic us o. s a G S t 45 ta nd I recently purchased the Multi-Volt Bench Power Supply from the April 2002 issue. After construction, I found that the -3V rail was -3.7V and the -9V rail was -4.8V; all the rest were the correct voltage. Radiometrix_Australia latest.q 12/8/04 the number of computers involved and the amount of use of the USB makes the cost prohibitive. Can you can come up with a solution? (B. P., Maryborough, Qld). • In almost all cases, information on motherboard USB header pinouts can be tracked down on the Internet. In addition, the +5V and GND connections can be quickly verified with a multimeter, thereby preventing the serious damage that could occur if these two are reversed. Your idea sounds interesting but as you suggest, many users are opting for USB2 upgrades on older systems. The cost of USB2 cards is now probably less than any project we could develop. Radiometrix modules are suitable for Australian and New Zealand markets. The modules are capable of long range performance of up to 10 Km and are a cost-effective solution to wireless data transmission problems. TX1H / RX1 • Standard frequency 151.300MHz • Other frequencies from 120MHz to 180MHz • Data rates up to 10kbps TX1H Transmitter • 100 mW Transmitter • Usable range over 10km • Supply range: 3.8V - 15V • Current consumption: 80mA transmit • TX1H has same pin-out as TX1 RX1 Receiver • Single conversion NBFM superhet Image rejection >50dB • Operation from 2.7V to 12V <at> 12mA • Built-in regulator for improved stability noise rejection - 116dBm sensitivity <at> 1ppm BER • RSSI output with >80dB range Local oscillator leakage <-60dBm Enable facility TX2 / RX2 CE certified by independent Notified Body • Data rates up to 160 kbps • Usable range up to 300 m • Operates on 433.92 MHz TX2 Transmitter (25 mW version available) • Operation from 2.2V to 6V +9dBm on 433.92MHz • High efficiency, >15%, DC RF 2nd harmonic RX2 Receiver • Double conversion FM superhet • SAW front end filter, image rejection 50dB • Supply 3.0V to 6.0V <at> 13mA -107 dBm sensitivity <at> 1ppm BER with 14kbps-version • LO leakage, < -60 dBm BiM1 BiM1 Transceiver • Standard frequency 151.300MHz • Available separately as BiM1T transmitter and BiM1R receiver • Data rates up to 10kbps for standard module • Usable range over 10km Feature-rich interface (RSSI, analogue and digital baseband) • Supply range: 100mW Transmitter 3.8V - 15V, Receiver: 3.0V - 15V • Current consumption: 80mA transmit, 8mA receive • RSSI output with >60dBm range 10kbps, -120dBm sensitivity (for 12 dB SINAD) BiM2 BiM2 Transceiver • Usable range to 200 metres external, 50 metres in building • Operates on 433.92 MHz • Data rates up to 160kbps • SAW controlled 10mW FM transmitter • Double conversion FM superhet receiver • SAW front end filter and full screening • 3V or 5Volt supply at < 20mA Revised pricing structure for Australia! Same great products at lower prices! A range of frequencies are available including: 151.300 MHz (100 mW) 173.225 MHz (100 mW) 433.92 MHz (25 mW 918.525MHz Contact our NEW Australian & New Zealand distributor for sales information RF Modules Australia P.O. Box 1957 Launceston TAS, 7250 Tel: +61 3-6331-6789 Fax: +61 3-6331-1243 sales<at>rfmodules.com.au www.rfmodules.com.au Full technical details are available online at: www.radiometrix.com siliconchip.com.au September 2004  87 Connecting The High-Energy Ignition I have just a couple of dumb questions regarding the kit “Universal High Energy Ignition” published in the June 1988 issue. I’ve built the points version of the kit. First and probably the dumbest question is where is the positive side of the points? I can find the chassis side easily enough. Do I have to cut into some wires (like the main cable coming from the coil centre to the distributor)? The other stupid question is this: if the centre pin of Q1 (BUP941) is connected to the coil negative, why all the effort to isolate Q1’s back tab from the case? The construction side of the kit is fairly straightforward; it’s just the connection info that’s leaving me stumped. (S. S., Seaford, Vic). have a couple of the resistors swapped – one of them for the 3V position of S3 and the 9V position of S4. It’s hard to see what else could cause these faults, apart from perhaps faulty rotary switches or switches with the stop plate in the wrong position. Joystick control of car windows I am undertaking a project using your DC motor speed controller circuit from June 1997. I need to use a single control circuit or device (joystick/ trimpot, etc) to vary both speed and direction of a car window motor. Can you help? (L. W., via email). • We suggest you look at the Train Controller in the April 1997 issue of SILICON CHIP. This provides speed and direction control with a single pot. Battery Guardian disconnects fridge I recently built a 12V Battery Guardian from the May 2002 issue. In my vehicle, I have two batteries which are isolated from each other when the ignition is turned off; it is a fairly typical set up in 4WD vehicles. One battery looks after the normal vehicle electrics while the second battery runs a fridge, lights, etc. 88  Silicon Chip • The positive side of the points goes to the negative side of the coil in your existing set up. So take the negative wire off the coil – it becomes the positive points wire. You then run an additional wire from the coil negative to the collector of Q1. Do not touch the distributor HT wire from the coil – it stays as is. Q1’s back tab is internally connected to its collector pin and it has high voltage on it as it switches. If you touch it while it is operating you will get a hell of a kick from it. So it must be insulated from the case. By the way, we updated that project in the June 1998 issue of SILICON CHIP and then re-published it in “Electronic Projects for Cars, Vol 2”. As the second battery is not used to start the engine, I set the Guardian’s turn-off point at 10.75V and the turn-on point was left at 12.5V. This works fine when running lights, etc on the output (ie, items which draw a constant current) but I have a 39-litre ENGEL brand fridge in the vehicle which draws 3.5A when running. This fridge creates a problem as follows. With the battery voltage at 12.5V, when I turn on the fridge, the Battery Guardian immediately turns off and starts beeping. If I leave the fridge turned on and start the engine to raise the battery voltage above 12.5V, the Battery Guardian reconnects the fridge, stops beeping and the fridge runs, so the engine can now be turned off. The fridge continues to run till such time as the correct temperature is reached and the compressor in the fridge turns off. As the temperature in the fridge rises, the compressor turns on and starts the above cycle again; ie, the Battery Guardian disconnects the battery and starts beeping. I assume that this is caused by the battery voltage dropping below 10.75V for an instant as the compressor is starting or the current surge during start up is causing the problem. I thought that the Guardian would leave the battery connected for a short period as the compressor starts rather than disconnect the battery instantly. Do you have any suggestions? (B. C., Carina, Qld). • The Battery Guardian should work reliably even though the fridge draws more current during start-up. Your battery is probably old and on its way out. It may have a high impedance cell that drops rapidly in voltage with load. Have the battery checked. Changing the slope on a sawtooth I need to generate a non-alternating sawtooth waveform where the “up” section is very steep (ie, fast) and the “down” portion slower. Many sawtooth examples I’ve seen, and indeed most circuit diagrams, demonstrate a sawtooth where the incline is slow and the decay rapid. I need the opposite! I was wondering whether you could suggest a method of constructing this? Also, I had the idea of taking a simple sawtooth generator and simply rectifying it; in a sense “reflecting” the negative wave so it became positive. Would that work? (M. W., via email). • As a general rule, if you want different slopes on a sawtooth oscillator, you arrange for separate charge and discharge paths to the capacitor in the RC network. In practice, you can do this with diodes, one for the charge resistor and a separate one in the opposite direction for the discharge resistor. Alternatively, if you have a sawtooth oscillator and you want to change its charge and discharge slopes, you could feed its signal through an inverting amplifier. This is the same as your “reflecting” idea. Programming the Fuel Mixture Display chip I’ve downloaded your software (Air Fuel Mixture Display; September/October 2003) to program the PIC16F84 in .asm and when I’m trying to program it on my PIC, MPLAB (Microchip program) said some errors like: Error[118] D:\AIRFUEL.ASM 627 : Overwriting previous address contents (0282). Warning[207] D:\AIRFUEL.ASM 1024: Found label after column 1. (clrw). Error[113] D:\AIRFUEL.ASM 1029: Symbol not previously defined siliconchip.com.au Error[113] D:\AIRFUEL.ASM 1041: Symbol not previously defined (z). Can you help me resolve this problem please? I would like so much to make a Fuel Mixture Display for my car. (F. R., Rawdon, Canada). • The microcontroller program for this project is also available for download as a “.HEX” file, suitable for use with your PIC programmer without modification. It is not necessary to assemble the “.ASM” file unless you specifically want to modify the original code. To get the AIRFUEL.ASM file to assemble successfully in MPLAB, you need to disable case sensitivity. This setting is to be found under “Project -> Build Options” on the “MPASM Assembler” tab. Note that you will still get a number of “Register in operand not in bank 0. Ensure that bank bits are correct” messages. These are just warning messages and can be ignored. PWM train controller wanted I am looking for a PWM (pulse width modulation) circuit for model trains. I used an old “Electronics Australia” project but mislaid the diagram. Its output stage used 2N3055s and the most important bit I cannot remember is the final stage crowbar circuit that protects the system using an SCR to inject a signal into the circuit to shut down the supply and illuminate a lamp. This is reset via a push-button. I cannot afford the fancy new DCC (Digital Command Control) circuits. I have both books by Roger Amos (“Practical Electronics For Model Railways”) but he fails to incorporate any simple overload protection using Notes & Errata Micropower Battery Protector, July 2004: The article stated that the MAX8212CPA voltage monitor (IC1) is available from Farnell. Unfortunately, Farnell has discontinued this part. Wiltronics currently have the part listed in their catalog. Check their website at www.wiltronics. com.au or phone 1800 067 674 for availability. Alternatively, you can order a kit of parts for the project from Dick Smith Electronics, Cat. K-3132. SILICON CHIP has also recently become aware of a number of “bogus” MAX8212CPA chips that are being sold on the “grey” market. These devices are easily identified in-circuit because they behave in an opposite fashion to a properly functioning device. In “bogus” devices, the output N-channel FET turns on when the voltage applied to the THRESH input (pin 3) is less than the internal reference voltage. This causes the MOSFET (Q1) to turn on when the input voltage is below the set point, rather than above this point. 3V to 9V DC-DC Converter, March 2004: when the trickle charge circuit (D2 & R4) is installed and the converter is powered from the plugpack the SCR method. Can you help? I am sure their would be lots of modellers out there wanting a similar circuit for model trains. (D. R., Ruatapu, NZ). • We have published quite a few PWM train controllers over the years. input without a battery connected, the output voltage will fall short of 9V. This occurs because the tricklecharge circuit is pulling the “SW” pin higher than the “VIN2” pin, causing the TL499A to erroneously select the step-up switching regulator instead of the linear regulator. If you must operate the unit from a plugpack without a battery installed, then you can solve this problem two ways: (1). Remove the trickle charge components (D2 & R4), or (2). Fit a 2-pin header so that the trickle-charge circuit can be disabled (via a jumper shunt) at will. You will note on the circuit board layout that provision has been made for this directly below D2. First, remove D2 and cut the small track that joins the two square pads. Install a 2-pin header and refit D2, noting that you’ll probably need a new diode with longer leads so that it can be positioned between the new header and L1. 50W DC Electronic Load, September 2002: the circuit diagram (Fig.2) shows the input pin numbers for IC1b in reverse. The non-inverting input should be pin 5 and the inverting input pin 6. The most recent are the deluxe Railpower published in October/November/December 1999 and the Li’l Pulser in the February 2001 issue. All our PWM designs incorporate overload SC protection. 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 September 2004  89 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* 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. 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. 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. 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 PRACTICAL RF HANDBOOK by Carl Vogel. Published 2009. $40.00* by Ian Hickman. 4th edition 2007 $61.00* A guide to RF design for engineers, technicians, students and enthusiasts. Covers key topics in RF: analog design principles, transmission lines, couplers, transformers, amplifiers, oscillators, modulation, transmitters and receivers, propagation and antennas. 279 pages in paperback. Alternative fuel expert Carl Vogel gives you a hands-on guide with the latest technical information and easy-to-follow instructions for building a two-wheeled electric vehicle – from a streamlined scooter to a full-sized motorcycle. 384 pages in soft cover. *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* 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. 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. 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. 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 PRACTICAL RF HANDBOOK by Carl Vogel. Published 2009. $40.00* by Ian Hickman. 4th edition 2007 $61.00* A guide to RF design for engineers, technicians, students and enthusiasts. Covers key topics in RF: analog design principles, transmission lines, couplers, transformers, amplifiers, oscillators, modulation, transmitters and receivers, propagation and antennas. 279 pages in paperback. Alternative fuel expert Carl Vogel gives you a hands-on guide with the latest technical information and easy-to-follow instructions for building a two-wheeled electric vehicle – from a streamlined scooter to a full-sized motorcycle. 384 pages in soft cover. *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 Silicon Chip Back Issues November 1994: Dry Cell Battery Rejuvenator; Novel Alphanumeric Clock; 80-M DSB Amateur Transmitter; 2-Cell Nicad Discharger. April 1989: Auxiliary Brake Light Flasher; What You Need to Know About Capacitors; 32-Band Graphic Equaliser, Pt.2. April 1992: IR Remote Control For Model Railroads; Differential Input Buffer For CROs; Aligning Vintage Radio Receivers, Pt.1. May 1989: Build A Synthesised Tom-Tom; Biofeedback Monitor For Your PC; Simple Stub Filter For Suppressing TV Interference. June 1992: Multi-Station Headset Intercom, Pt.1; Video Switcher For Camcorders & VCRs; IR Remote Control For Model Railroads, Pt.3; 15-Watt 12-240V Inverter; A Look At Hard Disk Drives. July 1989: Exhaust Gas Monitor; Experimental Mains Hum Sniffers; Compact Ultrasonic Car Alarm; The NSW 86 Class Electrics. September 1989: 2-Chip Portable AM Stereo Radio Pt.1; High Or Low Fluid Level Detector; Studio Series 20-Band Stereo Equaliser, Pt.2. October 1992: 2kW 24VDC - 240VAC Sinewave Inverter; Multi-Sector Home Burglar Alarm, Pt.2; Mini Amplifier For Personal Stereos; A Regulated Lead-Acid Battery Charger. October 1989: FM Radio Intercom For Motorbikes Pt.1; GaAsFet Preamplifier For Amateur TV; 2-Chip Portable AM Stereo Radio, Pt.2. February 1993: Three Projects For Model Railroads; Low Fuel Indicator For Cars; Audio Level/VU Meter (LED Readout); An Electronic Cockroach; 2kW 24VDC To 240VAC Sinewave Inverter, Pt.5. November 1989: Radfax Decoder For Your PC (Displays Fax, RTTY & Morse); FM Radio Intercom For Motorbikes, Pt.2; 2-Chip Portable AM Stereo Radio, Pt.3; Floppy Disk Drive Formats & Options. March 1993: Solar Charger For 12V Batteries; Reaction Trainer; Audio Mixer for Camcorders; A 24-Hour Sidereal Clock For Astronomers. January 1990: High Quality Sine/Square Oscillator; Service Tips For Your VCR; Active Antenna Kit; Designing UHF Transmitter Stages. February 1990: A 16-Channel Mixing Desk; Build A High Quality Audio Oscillator, Pt.2; The Incredible Hot Canaries; Random Wire Antenna Tuner For 6 Metres; Phone Patch For Radio Amateurs, Pt.2. March 1990: Delay Unit For Automatic Antennas; Workout Timer For Aerobics Classes; 16-Channel Mixing Desk, Pt.2; Using The UC3906 SLA Battery Charger IC. April 1990: Dual Tracking ±50V Power Supply; Voice-Operated Switch With Delayed Audio; 16-Channel Mixing Desk, Pt.3; Active CW Filter. June 1990: Multi-Sector Home Burglar Alarm; Build A Low-Noise Universal Stereo Preamplifier; Load Protector For Power Supplies. July 1993: Single Chip Message Recorder; Light Beam Relay Extender; AM Radio Trainer, Pt.2; Quiz Game Adjudicator; Antenna Tuners – Why They Are Useful. July 1995: Electric Fence Controller; How To Run Two Trains On A Single Track (Incl. Lights & Sound); Setting Up A Satellite TV Ground Station; Build A Reliable Door Minder. August 1993: Low-Cost Colour Video Fader; 60-LED Brake Light Array; Microprocessor-Based Sidereal Clock; Satellites & Their Orbits. September 1993: Automatic Nicad Battery Charger/Discharger; Stereo Preamplifier With IR Remote Control, Pt.1; In-Circuit Transistor Tester; +5V to ±15V DC Converter; Remote-Controlled Cockroach. September 1990: 3-Digit Counter Module; Simple Shortwave Converter For The 2-Metre Band; Taking Care Of Nicad Battery Packs. December 1993: Remote Controller For Garage Doors; LED Stroboscope; 25W Audio Amplifier Module; A 1-Chip Melody Generator; Engine Management, Pt.3; Index To Volume 6. May 1991: 13.5V 25A Power Supply For Transceivers; Stereo Audio Expander; Fluorescent Light Simulator For Model Railways; How To Install Multiple TV Outlets, Pt.1. July 1991: Loudspeaker Protector For Stereo Amplifiers; 4-Channel Lighting Desk, Pt.2; How To Install Multiple TV Outlets, Pt.2; Tuning In To Satellite TV, Pt.2. September 1991: Digital Altimeter For Gliders & Ultralights; Ultrasonic Switch For Mains Appliances; The Basics Of A/D & D/A Conversion. October 1991: A Talking Voltmeter For Your PC, Pt.1; SteamSound Simulator For Model Railways Mk.II; Magnetic Field Strength Meter; Digital Altimeter For Gliders, Pt.2; Military Applications Of R/C Aircraft. November 1991: Build A Colour TV Pattern Generator, Pt.1; A Junkbox 2-Valve Receiver; Flashing Alarm Light For Cars; Digital Altimeter For Gliders, Pt.3; A Talking Voltmeter For Your PC, Pt.2. December 1991: TV Transmitter For VCRs With UHF Modulators; IR Light Beam Relay; Colour TV Pattern Generator, Pt.2; Index To Vol.4. March 1992: TV Transmitter For VHF VCRs; Thermostatic Switch For Car Radiator Fans; Valve Substitution In Vintage Radios. ORDER FORM April 1995: FM Radio Trainer, Pt.1; Balanced Mic Preamp & Line Filter; 50W/Channel Stereo Amplifier, Pt.2; Wide Range Electrostatic Loudspeakers, Pt.3; 8-Channel Decoder For Radio Remote Control. June 1995: Build A Satellite TV Receiver; Train Detector For Model Railways; 1W Audio Amplifier Trainer; Low-Cost Video Security System; Multi-Channel Radio Control Transmitter For Models, Pt.1. November 1993: High Efficiency Inverter For Fluorescent Tubes; Stereo Preamplifier With IR Remote Control, Pt.3; Siren Sound Generator; Engine Management, Pt.2; Experiments For Games Cards. March 1991: Transistor Beta Tester Mk.2; A Synthesised AM Stereo Tuner, Pt.2; Multi-Purpose I/O Board For PC-Compatibles; Wideband RF Preamplifier For Amateur Radio & TV. March 1995: 2 x 50W Stereo Amplifier, Pt.1; Subcarrier Decoder For FM Receivers; Wide Range Electrostatic Loudspeakers, Pt.2; IR Illuminator For CCD Cameras; Remote Control System For Models, Pt.3. June 1993: AM Radio Trainer, Pt.1; Remote Control For The Woofer Stopper; Digital Voltmeter For Cars. August 1990: High Stability UHF Remote Transmitter; Universal Safety Timer For Mains Appliances (9 Minutes); Horace The Electronic Cricket; Digital Sine/Square Generator, Pt.2. January 1991: Fast Charger For Nicad Batteries, Pt.1; Have Fun With The Fruit Machine (Simple Poker Machine); Two-Tone Alarm Module; The Dangers of Servicing Microwave Ovens. February 1995: 2 x 50W Stereo Amplifier Module; Digital Effects Unit For Musicians; 6-Channel Thermometer With LCD Readout; Wide Range Electrostatic Loudspeakers, Pt.1; Oil Change Timer For Cars; Remote Control System For Models, Pt.2. May 1995: Guitar Headphone Amplifier; FM Radio Trainer, Pt.2; Transistor/Mosfet Tester For DMMs; A 16-Channel Decoder For Radio Remote Control; Introduction To Satellite TV. October 1993: Courtesy Light Switch-Off Timer For Cars; Wireless Microphone For Musicians; Stereo Preamplifier With IR Remote Control, Pt.2; Electronic Engine Management, Pt.1. November 1990: Connecting Two TV Sets To One VCR; Build An Egg Timer; Low-Cost Model Train Controller; 1.5V To 9V DC Converter; Introduction To Digital Electronics; A 6-Metre Amateur Transmitter. January 1995: Sun Tracker For Solar Panels; Battery Saver For Torches; Dual Channel UHF Remote Control; Stereo Microphone Pre­amp­lifier. April 1993: Solar-Powered Electric Fence; Audio Power Meter; ThreeFunction Home Weather Station; 12VDC To 70VDC Converter. July 1990: Digital Sine/Square Generator, Pt.1 (0-500kHz); Burglar Alarm Keypad & Combination Lock; Build A Simple Electronic Die; October 1990: The Dangers of PCBs; Low-Cost Siren For Burglar Alarms; Dimming Controls For The Discolight; Surfsound Simulator; DC Offset For DMMs; NE602 Converter Circuits. December 1994: Car Burglar Alarm; Three-Spot Low Distortion Sinewave Oscillator; Clifford – A Pesky Electronic Cricket; Remote Control System for Models, Pt.1; Index to Vol.7. August 1995: Fuel Injector Monitor For Cars; Gain Controlled Microphone Preamp; How To Identify IDE Hard Disk Drive Parameters. September 1995: Railpower Mk.2 Walkaround Throttle For Model Railways, Pt.1; Keypad Combination Lock; Jacob’s Ladder Display. October 1995: 3-Way Loudspeaker System; Railpower Mk.2 Walkaround Throttle For Model Railways, Pt.2; Nicad Fast Charger. January 1994: 3A 40V Variable Power Supply; Solar Panel Switching Regulator; Printer Status Indicator; Mini Drill Speed Controller; Stepper Motor Controller; Active Filter Design; Engine Management, Pt.4. February 1994:90-Second Message Recorder; 12-240VAC 200W Inverter; 0.5W Audio Amplifier; 3A 40V Adjustable Power Supply; Engine Management, Pt.5; Airbags In Cars – How They Work. March 1994: Intelligent IR Remote Controller; 50W (LM3876) Audio Amplifier Module; Level Crossing Detector For Model Railways; Voice Activated Switch For FM Microphones; Engine Management, Pt.6. November 1995: Mixture Display For Fuel Injected Cars; CB Trans­verter For The 80M Amateur Band, Pt.1; PIR Movement Detector. December 1995: Engine Immobiliser; 5-Band Equaliser; CB Transverter For The 80M Amateur Band, Pt.2; Subwoofer Controller; Knock Sensing In Cars; Index To Volume 8. January 1996: Surround Sound Mixer & Decoder, Pt.1; Magnetic Card Reader; Automatic Sprinkler Controller; IR Remote Control For The Railpower Mk.2; Recharging Nicad Batteries For Long Life. April 1996: 125W Audio Amplifier Module; Knock Indicator For Leaded Petrol Engines; Multi-Channel Radio Control Transmitter; Pt.3. May 1996: High Voltage Insulation Tester; Knightrider LED Chaser; Simple Intercom Uses Optical Cable; Cathode Ray Oscilloscopes, Pt.3. June 1996: Stereo Simulator (uses delay chip); Rope Light Chaser; Low Ohms Tester For Your DMM; Automatic 10A Battery Charger. April 1994: Sound & Lights For Model Railway Level Crossings; Dual Supply Voltage Regulator; Universal Stereo Preamplifier; Digital Water Tank Gauge; Engine Management, Pt.7. May 1994: Fast Charger For Nicad Batteries; Induction Balance Metal Locator; Multi-Channel Infrared Remote Control; Dual Electronic Dice; Simple Servo Driver Circuits; Engine Management, Pt.8. June 1994: A Coolant Level Alarm For Your Car; 80-Metre AM/CW Transmitter For Amateurs; Converting Phono Inputs To Line Inputs; PC-Based Nicad Battery Monitor; Engine Management, Pt.9. July 1996: VGA Digital Oscilloscope, Pt.1; Remote Control Extender For VCRs; 2A SLA Battery Charger; 3-Band Parametric Equaliser;. August 1996: Introduction to IGBTs; Electronic Starter For Fluores­cent Lamps; VGA Oscilloscope, Pt.2; 350W Amplifier Module; Masthead Amplifier For TV & FM; Cathode Ray Oscilloscopes, Pt.4. September 1996: VGA Oscilloscope, Pt.3; IR Stereo Headphone Link, Pt.1; High Quality PA Loudspeaker; 3-Band HF Amateur Radio Receiver; Cathode Ray Oscilloscopes, Pt.5. October 1996: Send Video Signals Over Twisted Pair Cable; 600W DC-DC Converter For Car Hifi Systems, Pt.1; IR Stereo Headphone Link, Pt.2; Multi-Channel Radio Control Transmitter, Pt.8. July 1994: Build A 4-Bay Bow-Tie UHF TV Antenna; PreChamp 2-Transistor Preamplifier; Steam Train Whistle & Diesel Horn Simulator; 6V SLA Battery Charger; Electronic Engine Management, Pt.10. August 1994: High-Power Dimmer For Incandescent Lights; Dual Diversity Tuner For FM Microphones, Pt.1; Nicad Zapper (For Resurrecting Nicad Batteries); Electronic Engine Management, Pt.11. September 1994: Automatic Discharger For Nicad Batteries; MiniVox Voice Operated Relay; AM Radio For Weather Beacons; Dual Diversity Tuner For FM Mics, Pt.2; Electronic Engine Management, Pt.12. October 1994: How Dolby Surround Sound Works; Dual Rail Variable Power Supply; Talking Headlight Reminder; Electronic Ballast For Fluorescent Lights; Electronic Engine Management, Pt.13. November 1996: 8-Channel Stereo Mixer, Pt.1; Low-Cost Fluorescent Light Inverter; Repairing Domestic Light Dimmers; 600W DC-DC Converter For Car Hifi Systems, Pt.2. December 1996: Active Filter For CW Reception; Fast Clock For Railway Modellers; Laser Pistol & Electronic Target; Build A Sound Level Meter; 8-Channel Stereo Mixer, Pt.2; Index To Vol.9. January 1997: How To Network Your PC; Control Panel For Multiple Smoke Alarms, Pt.1; Build A Pink Noise Source; Computer Controlled Dual Power Supply, Pt.1; Digi-Temp Monitors Eight Temperatures. February 1997: PC-Con­trolled Moving Message Display; Computer Please send the following back issues:________________________________________ Enclosed is my cheque/money order for $­______or please debit my:  Bankcard  Visa Card  Master Card Card No. Signature ___________________________ Card expiry date_____ /______ Name ______________________________ Phone No (___) ____________ PLEASE PRINT Street ______________________________________________________ Suburb/town _______________________________ Postcode ___________ 92  Silicon Chip 10% OF SUBSCR F TO IB OR IF Y ERS OU 10 OR M BUY ORE Note: prices include postage & packing Australia ............................... $A8.80 (incl. GST) Overseas (airmail) ..................................... $A10 Detach and mail to: Silicon Chip Publications, PO Box 139, Collaroy, NSW, Australia 2097. Or call (02) 9979 5644 & quote your credit card details or fax the details to (02) 9979 6503. Email: silchip<at>siliconchip.com.au siliconchip.com.au Controlled Dual Power Supply, Pt.2; Alert-A-Phone Loud Sounding Telephone Alarm; Control Panel For Multiple Smoke Alarms, Pt.2. Pt.1; LED Christmas Tree; Intercom Station Expander; Foldback Loudspeaker System; Railpower Model Train Controller, Pt.2. March 1997: Driving A Computer By Remote Control; Plastic Power PA Amplifier (175W); Signalling & Lighting For Model Railways; Build A Jumbo LED Clock; Cathode Ray Oscilloscopes, Pt.7. December 1999: Solar Panel Regulator; PC Powerhouse (gives +12V, +9V, +6V & +5V rails); Fortune Finder Metal Locator; Speed Alarm For Cars, Pt.2; Railpower Model Train Controller, Pt.3; Index To Vol.12. April 1997: Simple Timer With No ICs; Digital Voltmeter For Cars; Loudspeaker Protector For Stereo Amplifiers; Model Train Controller; A Look At Signal Tracing; Pt.1; Cathode Ray Oscilloscopes, Pt.8. January 2000: Spring Reverberation Module; An Audio-Video Test Generator; Picman Programmable Robot; Parallel Port Interface Card; Off-Hook Indicator For Telephones. May 1997: Neon Tube Modulator For Light Systems; Traffic Lights For A Model Intersection; The Spacewriter – It Writes Messages In Thin Air; A Look At Signal Tracing; Pt.2; Cathode Ray Oscilloscopes, Pt.9. February 2000: Multi-Sector Sprinkler Controller; A Digital Voltmeter For Your Car; Safety Switch Checker; Sine/Square Wave Oscillator. June 1997: PC-Controlled Thermometer/Thermostat; TV Pattern Generator, Pt.1; Audio/RF Signal Tracer; High-Current Speed Controller For 12V/24V Motors; Manual Control Circuit For Stepper Motors. July 1997: Infrared Remote Volume Control; A Flexible Interface Card For PCs; Points Controller For Model Railways; Colour TV Pattern Generator, Pt.2; An In-Line Mixer For Radio Control Receivers. August 1997: The Bass Barrel Subwoofer; 500 Watt Audio Power Amplifier Module; A TENs Unit For Pain Relief; Addressable PC Card For Stepper Motor Control; Remote Controlled Gates For Your Home. October 1997: 5-Digit Tachometer; Central Locking For Your Car; PCControlled 6-Channel Voltmeter; 500W Audio Power Amplifier, Pt.3. November 1997: Heavy Duty 10A 240VAC Motor Speed Controller; Easy-To-Use Cable & Wiring Tester; Build A Musical Doorbell; Replacing Foam Speaker Surrounds; Understanding Electric Lighting Pt.1. December 1997: Speed Alarm For Cars; 2-Axis Robot With Gripper; Stepper Motor Driver With Onboard Buffer; Power Supply For Stepper Motor Cards; Understanding Electric Lighting Pt.2; Index To Vol.10. January 1998: 4-Channel 12VDC or 12VAC Lightshow, Pt.1; Command Control For Model Railways, Pt.1; Pan Controller For CCD Cameras. February 1998: Multi-Purpose Fast Battery Charger, Pt.1; Telephone Exchange Simulator For Testing; Command Control System For Model Railways, Pt.2; Build Your Own 4-Channel Lightshow, Pt.2. April 1998: Automatic Garage Door Opener, Pt.1; 40V 8A Adjustable Power Supply, Pt.1; PC-Controlled 0-30kHz Sinewave Generator; Build A Laser Light Show; Understanding Electric Lighting; Pt.6. May 1998: Troubleshooting Your PC, Pt.1; 3-LED Logic Probe; Automatic Garage Door Opener, Pt.2; Command Control For Model Railways, Pt.4; 40V 8A Adjustable Power Supply, Pt.2. June 1998: Troubleshooting Your PC, Pt.2; Universal High Energy Ignition System; The Roadies’ Friend Cable Tester; Universal Stepper Motor Controller; Command Control For Model Railways, Pt.5. July 1998: Troubleshooting Your PC, Pt.3; 15W/Ch Class-A Audio Amplifier, Pt.1; Simple Charger For 6V & 12V SLA Batteries; Auto­ matic Semiconductor Analyser; Understanding Electric Lighting, Pt.8. August 1998: Troubleshooting Your PC, Pt.4; I/O Card With Data Logging; Beat Triggered Strobe; 15W/Ch Class-A Stereo Amplifier, Pt.2. September 1998: Troubleshooting Your PC, Pt.5; A Blocked Air-Filter Alarm; Waa-Waa Pedal For Guitars; Jacob’s Ladder; Gear Change Indicator For Cars; Capacity Indicator For Rechargeable Batteries. October 1998: AC Millivoltmeter, Pt.1; PC-Controlled Stress-O-Meter; Versatile Electronic Guitar Limiter; 12V Trickle Charger For Float Conditions; Adding An External Battery Pack To Your Flashgun. November 1998: The Christmas Star; A Turbo Timer For Cars; Build A Poker Machine, Pt.1; FM Transmitter For Musicians; Lab Quality AC Millivoltmeter, Pt.2; Improving AM Radio Reception, Pt.1. December 1998: Engine Immobiliser Mk.2; Thermocouple Adaptor For DMMs; Regulated 12V DC Plugpack; Build A Poker Machine, Pt.2; Improving AM Radio Reception, Pt.2; Mixer Module For F3B Gliders. January 1999: High-Voltage Megohm Tester; A Look At The BASIC Stamp; Bargraph Ammeter For Cars; Keypad Engine Immobiliser. March 1999: Getting Started With Linux; Pt.1; Build A Digital Anemometer; Simple DIY PIC Programmer; Easy-To-Build Audio Compressor; Low Distortion Audio Signal Generator, Pt.2. April 1999: Getting Started With Linux; Pt.2; High-Power Electric Fence Controller; Bass Cube Subwoofer; Programmable Thermostat/ Thermometer; Build An Infrared Sentry; Rev Limiter For Cars. May 1999: The Line Dancer Robot; An X-Y Table With Stepper Motor Control, Pt.1; Three Electric Fence Testers; Heart Of LEDs; Build A Carbon Monoxide Alarm; Getting Started With Linux; Pt.3. June 1999: FM Radio Tuner Card For PCs; X-Y Table With Stepper Motor Control, Pt.2; Programmable Ignition Timing Module For Cars, Pt.1; Hard Disk Drive Upgrades Without Reinstalling Software? July 1999: Build A Dog Silencer; 10µH to 19.99mH Inductance Meter; Audio-Video Transmitter; Programmable Ignition Timing Module For Cars, Pt.2; XYZ Table With Stepper Motor Control, Pt.3. August 1999: Remote Modem Controller; Daytime Running Lights For Cars; Build A PC Monitor Checker; Switching Temperature Controller; XYZ Table With Stepper Motor Control, Pt.4; Electric Lighting, Pt.14. September 1999: Autonomouse The Robot, Pt.1; Voice Direct Speech Recognition Module; Digital Electrolytic Capacitance Meter; XYZ Table With Stepper Motor Control, Pt.5; Peltier-Powered Can Cooler. October 1999: Build The Railpower Model Train Controller, Pt.1; Semiconductor Curve Tracer; Autonomouse The Robot, Pt.2; XYZ Table With Stepper Motor Control, Pt.6; Introducing Home Theatre. November 1999: Setting Up An Email Server; Speed Alarm For Cars, siliconchip.com.au March 2000: Resurrecting An Old Computer; Low Distortion 100W Amplifier Module, Pt.1; Electronic Wind Vane With 16-LED Display; Glowplug Driver For Powered Models; The OzTrip Car Computer, Pt.1. May 2000: Ultra-LD Stereo Amplifier, Pt.2; LED Dice (With PIC Microcontroller); Low-Cost AT Keyboard Translator (Converts IBM Scan-Codes To ASCII); 50A Motor Speed Controller For Models. June 2000: Automatic Rain Gauge; Parallel Port VHF FM Receiver; Switchmode Power Supply (1.23V to 40V) Pt.1; CD Compressor. August 2002: Digital Instrumentation Software For PCs; Digital Storage Logic Probe; Digital Therm./Thermostat; Sound Card Interface For PC Test Instruments; Direct Conversion Receiver For Radio Amateurs. September 2002: 12V Fluorescent Lamp Inverter; 8-Channel Infrared Remote Control; 50-Watt DC Electronic Load; Driving Light & Accessory Protector For Cars; Spyware – An Update. October 2002: Speed Controller For Universal Motors; PC Parallel Port Wizard; Cable Tracer; AVR ISP Serial Programmer; 3D TV. November 2002: SuperCharger For NiCd/NiMH Batteries, Pt.1; Windows-Based EPROM Programmer, Pt.1; 4-Digit Crystal-Controlled Timing Module; Using Linux To Share An Optus Cable Modem, Pt.1. December 2002: Receiving TV From Satellites; Pt.1; The Micromitter Stereo FM Transmitter; Windows-Based EPROM Programmer, Pt.2; SuperCharger For NiCd/NiMH Batteries; Pt.2; Simple VHF FM/AM Radio; Using Linux To Share An Optus Cable Modem, Pt.2. January 2003: Receiving TV From Satellites, Pt 2; SC480 50W RMS Amplifier Module, Pt.1; Gear Indicator For Cars; Active 3-Way Crossover For Speakers; Using Linux To Share An Optus Cable Modem, Pt.3. July 2000: Moving Message Display; Compact Fluorescent Lamp Driver; Musicians’ Lead Tester; Switchmode Power Supply, Pt.2. February 2003: PortaPal PA System, Pt.1; SC480 50W RMS Amplifier Module, Pt.2; Windows-Based EPROM Programmer, Pt.3; Using Linux To Share An Optus Cable Modem, Pt.4; Fun With The PICAXE, Pt.1. August 2000: Theremin; Spinner (writes messages in “thin-air”); Proximity Switch; Structured Cabling For Computer Networks. March 2003: LED Lighting For Your Car; Peltier-Effect Tinnie Cooler; PortaPal PA System, Pt.2; 12V SLA Battery Float Charger; Little Dynamite Subwoofer; Fun With The PICAXE, Pt.2 (Shop Door Minder). September 2000: Swimming Pool Alarm; 8-Channel PC Relay Board; Fuel Mixture Display For Cars, Pt.1; Protoboards – The Easy Way Into Electronics, Pt.1; Cybug The Solar Fly. October 2000: Guitar Jammer; Breath Tester; Wand-Mounted Inspection Camera; Subwoofer For Cars; Fuel Mixture Display, Pt.2. November 2000: Santa & Rudolf Chrissie Display; 2-Channel Guitar Preamplifier, Pt.1; Message Bank & Missed Call Alert; Protoboards – The Easy Way Into Electronics, Pt.3. December 2000: Home Networking For Shared Internet Access; White LED Torch; 2-Channel Guitar Preamplifier, Pt.2 (Digital Reverb); Driving An LCD From The Parallel Port; Index To Vol.13. April 2003: Video-Audio Booster For Home Theatre Systems; Telephone Dialler For Burglar Alarms; Three PIC Programmer Kits; PICAXE, Pt.3 (Heartbeat Simulator); Electric Shutter Release For Cameras. May 2003: Widgybox Guitar Distortion Effects Unit; 10MHz Direct Digital Synthesis Generator; Big Blaster Subwoofer; Printer Port Simulator; PICAXE, Pt.4 (Motor Controller). June 2003: PICAXE, Pt.5; PICAXE-Controlled Telephone Intercom; PICAXE-08 Port Expansion; Sunset Switch For Security & Garden Lighting; Digital Reaction Timer; Adjustable DC-DC Converter For Cars; Long-Range 4-Channel UHF Remote Control. January 2001: How To Transfer LPs & Tapes To CD; The LP Doctor – Clean Up Clicks & Pops, Pt.1; Arbitrary Waveform Generator; 2-Channel Guitar Preamplifier, Pt.3; PIC Programmer & TestBed. July 2003: Smart Card Reader & Programmer; Power-Up Auto Mains Switch; A “Smart” Slave Flash Trigger; Programmable Continuity Tester; PICAXE Pt.6 – Data Communications; Updating The PIC Programmer & Checkerboard; RFID Tags – How They Work. February 2001: An Easy Way To Make PC Boards; L’il Pulser Train Controller; A MIDI Interface For PCs; Build The Bass Blazer; 2-Metre Groundplane Antenna; The LP Doctor – Clean Up Clicks & Pops, Pt.2. August 2003: PC Infrared Remote Receiver (Play DVDs & MP3s On Your PC Via Remote Control); Digital Instrument Display For Cars, Pt.1; Home-Brew Weatherproof 2.4GHz WiFi Antennas; PICAXE Pt.7. March 2001: Making Photo Resist PC Boards; Big-Digit 12/24 Hour Clock; Parallel Port PIC Programmer & Checkerboard; Protoboards – The Easy Way Into Electronics, Pt.5; A Simple MIDI Expansion Box. September 2003: Robot Wars; Krypton Bike Light; PIC Programmer; Current Clamp Meter Adapter For DMMs; PICAXE Pt.8 – A Data Logger; Digital Instrument Display For Cars, Pt.2. April 2001: A GPS Module For Your PC; Dr Video – An Easy-To-Build Video Stabiliser; Tremolo Unit For Musicians; Minimitter FM Stereo Transmitter; Intelligent Nicad Battery Charger. October 2003: PC Board Design, Pt.1; JV80 Loudspeaker System; A Dirt Cheap, High-Current Power Supply; Low-Cost 50MHz Frequency Meter; Long-Range 16-Channel Remote Control System. May 2001: 12V Mini Stereo Amplifier; Two White-LED Torches To Build; PowerPak – A Multi-Voltage Power Supply; Using Linux To Share An Internet Connection, Pt.1; Tweaking Windows With TweakUI. November 2003: PC Board Design, Pt.2; 12AX7 Valve Audio Preamplifier; Our Best Ever LED Torch; Smart Radio Modem For Microcontrollers; PICAXE Pt.9; Programmable PIC-Powered Timer. June 2001: Universal Battery Charger, Pt.1; Phonome – Call, Listen In & Switch Devices On & Off; Low-Cost Automatic Camera Switcher; Using Linux To Share An Internet Connection, Pt.2; A PC To Die For, Pt.1. December 2003: How To Receive Weather Satellite Images; Self-Diagnostics Plug For Cars; PC Board Design, Pt.3; VHF Receiver For Weather Satellites; Linear Supply For Luxeon 1W Star LEDs; MiniCal 5V Meter Calibration Standard; PIC-Based Car Battery Monitor; PICAXE Pt.10. July 2001: The HeartMate Heart Rate Monitor; Do Not Disturb Tele­phone Timer; Pic-Toc – A Simple Alarm Clock; Fast Universal Battery Charger, Pt.2; A PC To Die For, Pt.2; Backing Up Your Email. August 2001: DI Box For Musicians; 200W Mosfet Amplifier Module; Headlight Reminder; 40MHz 6-Digit Frequency Counter Module; A PC To Die For, Pt.3; Using Linux To Share An Internet Connection, Pt.3. September 2001: Making MP3s; Build An MP3 Jukebox, Pt.1; PCControlled Mains Switch; Personal Noise Source For Tinnitus; Directional Microphone; Using Linux To Share An Internet Connection, Pt.4. November 2001: Ultra-LD 100W/Channel Stereo Amplifier, Pt.1; Neon Tube Modulator For Cars; Audio/Video Distribution Amplifier; Build A Short Message Recorder Player; Useful Tips For Your PC. December 2001: IR Transceiver For PCs; 100W/Ch Stereo Amplifier, Pt.2; Pardy Lights Colour Display; PIC Fun – Learning About Micros. January 2002: Touch And/Or Remote-Controlled Light Dimmer, Pt.1; A Cheap ’n’Easy Motorbike Alarm; 100W /Channel Stereo Amplifier, Pt.3; Build A Raucous Alarm; FAQs On The MP3 Jukebox. February 2002: 10-Channel IR Remote Control Receiver; 2.4GHz High-Power Audio-Video Link; Touch And/Or Remote-Controlled Light Dimmer, Pt.2; Booting A PC Without A Keyboard; 4-Way Event Timer. March 2002: Mighty Midget Audio Amplifier Module; 6-Channel IR Remote Volume Control, Pt.1; RIAA Pre­-­Amplifier For Magnetic Cartridges; 12/24V Intelligent Solar Power Battery Charger. April 2002:Automatic Single-Channel Light Dimmer; Pt.1; Water Level Indicator; Multiple-Output Bench Power Supply; Versatile Multi-Mode Timer; 6-Channel IR Remote Volume Control, Pt.2. May 2002: 32-LED Knightrider; The Battery Guardian (Cuts Power When the Battery Voltage Drops); Stereo Headphone Amplifier; Automatic Single-Channel Light Dimmer; Pt.2; Stepper Motor Controller. June 2002: Lock Out The Bad Guys with A Firewall; Remote Volume Control For Stereo Amplifiers; The “Matchless” Metal Locator; Compact 0-80A Automotive Ammeter; Constant High-Current Source. July 2002: Telephone Headset Adaptor; Rolling Code 4-Channel UHF Remote Control; Remote Volume Control For The Ultra-LD Stereo Amplifier; Direct Conversion Receiver For Radio Amateurs, Pt.1. January 2004: Studio 350W Power Amplifier Module, Pt.1; HighEfficiency Power Supply For 1W Star LEDs; Antenna & RF Preamp For Weather Satellites; Lapel Microphone Adaptor FOR PA Systems; PICAXE-18X 4-Channel Datalogger, Pt.1; 2.4GHZ Audio/Video Link. February 2004: PC Board Design For Beginners, Pt.1; Simple Supply Rail Monitor For PCs; Studio 350W Power Amplifier Module, Pt.2; Using The Valve Preamp In A Hifi System; Fantastic Human-Powered LED Torches; Shorted Turns Tester For Line Output Transformers; PICAXE-18X 4-Channel Datalogger, Pt.2. March 2004: PC Board Design For Beginners, Pt.2; Build The QuickBrake For Increased Driving Safety; 3V-9V (or more) DC-DC Converter; The ESR Meter Mk.2, Pt.1; Power Supply Demo Design; White LED Driver; PICAXE-18X 4-Channel Datalogger, Pt.3. April 2004: PC Board Design For Beginners, Pt.3; Loudspeaker Level Meter For Home Theatre Systems; Shut That Mutt (Electronic Dog Silencer); Smart Mixture Display For Cars; The ESR Meter Mk.2, Pt.2; PC/PICAXE Interface For UHF Remote Control. May 2004: Amplifier Testing Without High-Tech Gear; Component Video To RGB Converter; Starpower Switching Supply For Luxeon Star LEDs; Wireless Parallel Port; Poor Man’s Metal Locator. June 2004: Dr Video Mk.2 Video Stabiliser; Build An RFID Security Module; Fridge-Door Alarm; Courtesy Light Delay For Cars; Automating PC Power-Up; Upgraded Software For The EPROM Programmer. July 2004: Silencing A Noisy PC; Versatile Battery Protector; Appliance Energy Meter, Pt.1; A Poor Man’s Q Meter; Regulated High-Voltage Supply For Valve Amplifiers; Remote Control For A Model Train Layout. August 2004: Video Format: Why Bother?; VAF’s New DC-X Generation IV Loudspeaker System; Video Enhancer & Y/C Separator; Balanced Microphone Preamplifier; Appliance Energy Meter, Pt.2; Buils A 3-State Logic Probe. PLEASE NOTE: issues not listed have sold out. All other issues are in stock. We can supply photostat copies from sold-out issues for $8.80 per article (includes p&p). When supplying photostat articles or back copies, we automatically supply any relevant notes & errata at no extra charge. A complete index to all articles published to date can be downloaded free from our web site: www.siliconchip.com.au September 2004  93 MARKET CENTRE Cash in your surplus gear. Advertise it here in Silicon Chip. 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:__________________ 94  Silicon Chip FOR SALE Logbox and FieldLogger universal input dataloggers sPlan Windows electronic schematic software and Sprint Layout Windows PCB layout software are feature packed but low in price Labjack USB Data Acquisition Module features 8 12bit analog inputs, 20 digital I/O, 2 analog outputs and high speed counter. Free software, Labview driver and ActiveX component. DAS005 Parallel Port Data Acquisition Module features 8 12bit Analog inputs, 4 Digital I/Ps & 4 Digital O/Ps. Free windows software and source code. Pixel Programmable Controller with 4 analog inputs, 8 digital inputs and 8 relay outputs. Can use a 28A or 28X Picaxe. Programmed in basic or Flow chart. 2, 4 & 8 Relay Modules suitable for TTL and Open Collector Outputs. Programmers for Atmel and PIC microcontrollers. Stepper Motor 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 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 REALLY BRIGHT LEDS! 5mm superbrights from 35 cents each. 5mm RGB LEDs and other types available. New 100mA 5mm LEDs! Lithium batteries from 40 cents each. Check out my IN14 nixie tubes and new nixie clock kit! www. ledsales.com.au USB KITS: LCD Module Interface, Stepper Motor Controller, PIO Interface, DTMF Transceiver, Thermometer, DDS HF Generator, Compass, 4 Channel Voltmeter, I/O Relay Card. Also available, Digital Oscilloscope, Temperature Loggers, VHF Receivers and USB Acsiliconchip.com.au ELNEC IC PROGRAMMERS Satellite TV Reception Universal and specialised models High quality Realistic prices Large range of adaptors Free regular software updates Windows 95/98/Me/NT/2k/XP 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 GRANTRONICS PTY LTD PO Box 275, Wentworthville. 2145. Ph: 02 9896 7150 www.grantronics.com.au TAIG MACHINERY Micro Mini Lathes and Mills From $489.00 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) 9682 2487 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 tive X (and USBDOS.exe file) to control our kits from your application. www. ar.com.au/~softmark KITS KITS AND MORE KITS! Check ’em out at www.ozitronics.com HIGH PERFORMANCE GPS RECEIVERS FOR SALE: USB Mouse Receiver – $169.00; Compact Flash Receiver – $219.00. While Stocks Last! Enquiries to gps<at>livinet.com.au STOCK REDUCTION SALE: Every Friday 12pm to 5pm. Electronic components, switches, LEDs, displays, enclosures, connectors, crystals, relays, 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 speakerbits.com.au neons and many more. At Switches Plus Components, Unit 1 - 2 Sibthorpe Street, Braeside, Victoria. Phone (03) 9587 4044. S-Video . . . Video . . . Audio . . . VGA distribution amps, splitters, standards converters, tbc’s, switchers, cables, etc, & price list: www.questronix.com.au 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, Silicon Chip Binders H Heavy board covers with mottled dark green vinyl covering H Each binder holds up to 12 issues H SILICON CHIP logo printed on spine & cover. Price: $A12.95 plus $A7 per order (Australia only; not available elsewhere). Buy five and get them postage free. Just fill in & mail the handy order form in this issue; or fax (02) 9979 6503; or ring (02) 9979 5644 & quote your credit card number. siliconchip.com.au New New New REAL VALUE AT $12.95 PLUS P & P 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 PCBs MADE, ONE OR MANY. Any format, hobbyists welcome. Sesame Elec­tronics (02) 9593 1025. sesame777<at>optusnet.com.au http://sesame_elec.tripod.com 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 September 2004  95 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. Advertising Index Altronics................................. 72-75 Av-Comm.....................................95 Send to: Retail Operations Manager - Jaycar Electronics Pty Ltd P.O. Box 6424 Silverwater NSW 1811 Email: jobs<at>jaycar.com.au Dick Smith Electronics........... 18-23 Jaycar Electronics is an equal opportunity employer and actively promotes staff from within the organisation. Elexol...........................................59 Eco Watch....................................95 Evatco..........................................85 Grantronics...................................95 Harbuch Electronics.....................53 Silicon Chip Hy-Q International........................55 JED Microprocessors................5,55 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. 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: KIT ASSEMBLY Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. Circuit Ideas Wanted 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 EARLY HIFI’S, AMPLIFIERS, Speak- Instant PCBs................................96 Jaycar ......... 45-52,55,62-63,96,IFC Microgram Computers....................3 MicroZed Computers...............44,61 Newtek Sales...............................59 Oatley Electronics........................79 Ozitronics................................29,95 Quest Electronics....................55,95 Radiometrix..................................87 RCS Radio...................................94 ers, Turntables, Valves, Books, Quad, Leak, Pye, Lowther, 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 RF Probes....................................85 Silicon Chip Back Issues........ 92-93 Silicon Chip Binders................11,95 Silicon Chip Bookshop........... 90-91 SC Car Projects Book..................39 NOW AVAILABLE FROM Silicon Chip Subscriptions...........71 Silvertone Electronics..................95 Speakerbits..................................95 www.siliconchip.com.au Taig Machinery.............................95 Telelink Communications....55,OBC VAF Australia..............................IBC Project Reprints – Limited Back Issues –Limited One-Shots If you’re looking for a project from ELECTRONICS AUSTRALIA, you’ll find it at SILICON CHIP! We can now offer reprints of all projects which have appeared in Electronics Australia, EAT, Electronics Today, ETI or Radio, TV & Hobbies. First search the EA website indexes for the project you want and then call, fax or email us with the details and your credit card details. Reprint cost is $8.80 per article (ie, 2-part projects cost $17.60). SILICON CHIP subscribers receive a 10% discount. We also have limited numbers of EA back issues and special publications. Call for details! visit www.siliconchip.com.au or www.electronicsaustralia.com.au 96  Silicon Chip WIA..............................................55 ____________________________ PC Boards Printed circuit boards for SILICON CHIP projects are made by: RCS Radio Pty Ltd. Phone (02) 9738 0330. Fax (02) 9738 0334. siliconchip.com.au Loudspeaker breakthrough, . . . . again The original VAF DC-X loudspeaker was acclaimed as “A new benchmark in excellence in every criteria, innovation, design, finish and construction”. Background The VAF DC-X Reborn The VAF DC-X was launched as the cover story in Electronics Australia magazine in 1995 and was recognised as a genuine design and performance breakthrough. The new DC-X Gen IV builds on VAF’s legacy and is designed to simply offer maximum accuracy for minimum price. Advanced acoustic and mechanical design yielded a speaker with awesome dynamic capabilities and unmatched reproduction accuracy at its price. Countless ‘rave’ reviews have confirmed this. These include Rolling Stone, Australian Hi-Fi, Sound & Image, Audio Video Lifestyle, Best Buys Home Theatre, Electronics Australia, BRW, Best Buys Loudspeakers, and many other specialist publications and newspapers. Now a whole new chapter begins. Comprehensive information at www.vaf.com.au verifies the truly exceptional accuracy of the new DC-X. This accuracy ensures natural and precise sound reproduction, what ever music or movie you choose to play. With a 26-year legacy of innovation in audio from telecommunications to electro-acoustics, VAF has raised the state of the art in loudspeaker and acoustic design, . . . . again. Available only direct from VAF Research. FreeCall 1800 81 8882 www.vaf.com.au Home Theatre Packages available Ready to assemble also available VAF Research 52 North Tce Kent Town 5067 SA Tel 08 8363 9996 Fax 08 8363 9997 e-Mail vaf<at>vaf.com.au