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SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings.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.20, No.1; January 2007 SILICON CHIP www.siliconchip.com.au Features    8 Review: Yokogawa DL9000 Series Digital Scopes Yokogawa’s new digital oscilloscopes offer GHz bandwidth for less money than the competition and they won’t hog your desktop either – by Peter Smith 11 Biolock: Using Fingerprints To Unlock Doors No keys, no cards, no PINs . . . but it’s very secure – by Ross Tester 68 WiNRADiO: Marrying A Radio Receiver To A PC Versatile Temperature Switch – Page 22. Leading-edge Australian communications receivers link to a PC for awesome performance – by Kevin Poulter 76 “Degen” Synthesised HF Communications Receiver Tiny communications receiver covers the 100kHz to 30MHz MF/HF bands plus the 88-108MHz FM broadcast band – by Ross Tester 87 The Boony & Beefy Figurines The battle of the “tashes”. . . what makes them tick – by Leo Simpson Pro jects To Build 22 A Versatile Temperature Switch Adjustable design works all the way up to 245°C, has adjustable hysteresis & can switch on rising or falling temperatures – by John Clarke & Julian Edgar Intelligent Car Air Conditioner Controller – Page 28. 28 Intelligent Car Air-Conditioner Controller It stops your car’s air-conditioner from sapping engine power when going up hills or during overtaking. It could even save on fuel costs – by John Clarke 58 A Remote Telltale For Garage Doors Did you leave the garage door up or down? This unit uses a pair of UHF wireless modules & has LED indicators to tell you whether the door is fully up, fully down or somewhere in between – by Jim Rowe 78 Intelligent 12V Charger for SLA & Lead-Acid Batteries Here’s a cheap & simple battery charger which you can leave connected without risk of overcharge – by Branko Justic & Ross Tester Special Columns 39 Circuit Notebook (1) DRM Down-Converter For 455kHz IF Receivers; (2) Mechanical Soldering Iron Timer; (3) Toslink Splitter; (4) Telephone Intercom Using Old Handsets; (5) Versatile Multi-Driver Speaker Connections; (6) 3-Digit LED Stopwatch 44 Serviceman’s Log It’s no wonder I get aggravated – by the TV Serviceman 84 Salvage It! Remote Telltale For Garage Doors – Page 58. Intelligent 12V Charger For SLA & Lead-Acid Batteries – Page 78. The multi-purpose tape machine – by Julian Edgar 92 Vintage Radio The Philips RF5 Stereogram – by Rodney Champness Departments   2 Publisher’s Letter   4 Mailbag 57 Order Form siliconchip.com.au 90 Product Showcase 97 Ask Silicon Chip 101 Market Centre January 2007  1 SILICON CHIP www.siliconchip.com.au Publisher & Editor-in-Chief Leo Simpson, B.Bus., FAICD Production Manager Greg Swain, B.Sc.(Hons.) Technical Editor Peter Smith Technical Staff John Clarke, B.E.(Elec.) Ross Tester Jim Rowe, B.A., B.Sc, VK2ZLO Reader Services Ann Jenkinson Advertising Enquiries Glyn Smith Phone (02) 9939 3295 Mobile 0431 792 293 glyn<at>siliconchip.com.au Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Kevin Poulter Mike Sheriff, B.Sc, VK2YFK Stan Swan SILICON CHIP is published 12 times a year by Silicon Chip Publications Pty Ltd. ACN 003 205 490. ABN 49 003 205 490 All material copyright ©. No part of this publication may be reproduced without the written consent of the publisher. Printing: Hannanprint, Noble Park, Victoria. Distribution: Network Distribution Company. Subscription rates: $89.50 per year in Australia. For overseas rates, see the subscription page in this issue. Editorial office: Unit 1, 234 Harbord Rd, Brookvale, NSW 2100. Postal address: PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 9939 3295. Fax (02) 9939 2648. E-mail: silicon<at>siliconchip.com.au ISSN 1030-2662 * Recommended and maximum price only. 2  Silicon Chip Publisher’s Letter Today’s hospitals are full of electronics Just recently I had a short stint in hospital for a routine procedure and I must say that it was quite an experience, apart from the inevitable pain and inconvenience to normal routine. What impressed me most was the overwhelming presence of electronic equipment which is used at every stage of treatment. Of course, as soon as you are admitted, all your records are brought up on the hospital’s computer system. Then, as happened with me, you are connected up to an ECG machine to check the state of your heart and blood samples taken to check a variety of conditions. When you are wheeled into the operating room, you are confronted by an incredible array of electronic equipment. I then had a general anaesthetic so I was in no condition to appreciate all the high technology or ask any questions. Suffice to say that the electronic equipment is involved at every step, from the continual administering of drugs via a cannula (large needle!), to the monitoring of vital signs to the operation itself which was effectively done by remote control, via an endoscope and video camera. Before the operation I facetiously asked whether I could get a videotape of the procedure after it was finished. I was surprised to learn that indeed this was possible although it was not normally done to provide a keepsake for the patient – more as a record for the surgeon, to be used in subsequent care. Afterwards, in the recovery ward, you become aware of more electronic equipment. There is a machine to control the administration of drugs, saline solution or whatever and the inevitable machine used to monitor pulse, blood pressure and blood oxygen levels. Later you are wheeled into your room, accompanied by a drip machine and whatever plumbing as may be needed during the rest of your hospital stay. The drip machine is your constant companion and it gurgles away, day and night. And if you move in such a way as to cut off the flow, it will immediately begin chiming to let you and any nurse know that it demands attention. Right through your stay your pulse, blood pressure, blood oxygen levels and temperature will be regularly checked by a nurse. You are hooked up, the cuff on your upper arm inflates automatically and then deflates in steps as it records your diastolic and systolic pressure levels – incredible! Of course many people have one of these at home these days and so they are no longer a novelty but I still find the whole process a technical marvel. After a few days I was released to go home and thereby left all the beeping machines to get a good night’s sleep. But my overwhelming conclusion was how reliant we have become on electronics technology and how critical it would be if any of this equipment failed and was undetected after even a short time. At home, of course, if any of your electronic equipment fails, it can be annoying and inconvenient. But if a piece of electronic equipment used in a hospital fails it can be more than inconvenient, it could be immediately life threatening. My other conclusion was that ultimately, doctors and nurses are superb technicians, not only in their understanding of an immensely complicated system, the human body, but also in their understanding and application of electronics technology to many aspects of medicine. Leo Simpson PS: by the way, I’m now hale and hearty again! siliconchip.com.au Innovative • Unique • Interesting • Hard to find products What’s New? PCMCIA to Serial IP Pan & Tilt Camera This IP Camera is great for remote surveillance, the camera can be controlled remotely via a Web Browser. Cat 3629-7 $599 A basic cash register that is suitable for small retail outlets. Cat 1008129-7 $289 Temperature Logger Standalone "tag" loggers that can store up to 8000 readings with a temperature range of 40 to 850C. Multiple tags can be used in one reader. Cat 18211-7 Reader + Software $175 Cat 18210-7 Tags $69 Cat. No. Sharp Cash Register Add two serial ports to your notebook. Cat 2726-7 $269 DVD/CD Carousel Digital I/O to Ethernet This unit allows the user to remotely control 7 Digital I/O ports and 1 RS232/422/485 port over LAN or WAN. Cat 15157-7 $329 Holds up to 150 discs and comes with PC based software. Cat 6303-7 $269 HDMI Splitter Extend USB to 60m Outdoor AP & 12dBi Antenna Extend any USB 1.1 connection up to 60m over inexpensive UTP cable (not included) Cat 11683-7 $99 This all in one unit has an IP-66 rating and comes with a free POE injector. Cat 10223-7 $729 Cellular Router VGA Extender One HDMI input to four outputs. A two way splitter is also available. Cat 23052-7 $379 Description Price 1008272-7 3036-7 11493-7 11352-7 11293-7 1008265-7 Wireless Mini Keyboard with Trackball Hard Drive Auto Backup Device Print Server 2 USB Ports, supports Multifunctional devices Mini Print Server 1 Parallel Port Cat 1008272 Print Server 3 Parallel Ports Wireless VGA System - 802.11g Cat 1008265 $115 $299 $209 $129 $159 $549 11333-7 11334-7 11323-7 11324-7 5 Port Ethernet Switch 10/100 8 Port Ethernet Switch 10/100 16 Port Ethernet Switch 10/100 - Rack Mountable 24 Port Ethernet Switch 10/100 - Rack Mountable $39 $49 $99 $139 11435-7 11436-7 9402-7 11498-7 5 Port Gigabit Switch 10/100/1000 8 Port Gigabit Switch 10/100/1000 16 Port Gigabit Switch 10/100/1000 - Rack Mountable 24 Port Gigabit Switch 10/100/1000 - Rack Mountable $89 $129 $349 $499 6913-7 6858-7 6930-7 6898-7 3643-7 9433-7 eSATA External Case for 3.5" SATA HD Cat 6913 USB External Case for 3.5" SATA HD USB External Case for 1.8" Mini HD (As found in iPod etc) USB to IDE & SATA Adapter with Power - For 2.5" & 3.5" HDs USB Webcam with Infrared (Night Vision) ATX Power Supply Tester with LCD Display $99 $79 $99 $55 $68 $64 81211-7 81212-7 3659-7 3660-7 Large CD/DVD Storage Case - Holds up to 500 Discs Huge CD/DVD Storage Case - Holds up 880 Discs Internal VGA Splitter - 2 Port Internal VGA Splitter - 4 Port 1177-7 1168-7 4745-7 4363-7 11496-7 11499-7 12v Mini PC, Suitable for Cars, Boats, Caravans etc - Barebones 1Ghz 12v Mini PC Build - 1Ghz CPU, 40G HD, 512Mb DDR2 RAM, XP Pro 8" LCD Display with Touchscreen, VGA & Video Inputs - 12v 7" LCD Display with VGA & Video Inputs - 12v USB GPS Receiver - For use with a PC or Laptop Co Pilot Live 8 GPS Software for PCs or Laptops Cat 1177 Cat 9433 $69 $99 $99 $139 $1024 $1699 $579 $429 $199 $429 • Normally delivered next day • Not sure what product you require? Call us for friendly advice! ask<at>mgram.com.au RAID Server This device takes two IDE drives and mirrors them. If one drive fails it will work from the other until the faulty one is replaced and then rebuild "on the fly" to minimize downtime. Cat 2874-7 $569 1800 625 777 www.mgram.com.au Windows CE PCI to PCMCIA Adapter Terminal This PCI card allows the use of PCMCIA and PC Card devices designed for notebooks in a standard desktop PC. Cat 6539-7 $69 A PCI card that provides 48 digital I/O lines and three 16bit counters with a maximum count rate of 10MHz. Cat 17053-7 $249 SMS I/O Controller Mini Keyboard with Touchpad EPROM Programmer A high performance CE based terminal that supports RDP, Wyse Emulation & more. Cat 1248-7 $699 This programmer connects to the LPT port and has a 32 pin ZIF socket. It will program from 16k to 8M. Cat 3159-7 $479 Switch any electrical device on or off using SMS from any mobile phone. Cat 17087-7 $979 Reseller inquiries welcome siliconchip.com.au USB VGA Adapter Plugs into a USB 2.0 port and allows the user to extend their desktop over two screens (or three screens if already using a dual head video card). Cat 15156-7 $179 Compact 88 key keyboard with an integrated touch pad pointing device. It has two PS/2 connections for mouse and keyboard. Cordless model available. Cat 8751-7 $139 1800 625 777 ask<at>mgram.com.au www.mgram.com.au All prices subject to change without notice. For current pricing visit our website. Pictures are indicative only. January 2007  3 SHORE AD/MGRM0207 Connect multiple PCs to an EvDO mobile internet service. Cat 10211-7 $779 Extend VGA up to 130m over inexpensive STP cable. Cat 3441-7 $399 Digital I/O Card MAILBAG Valve amplifier lobbying Your editorial in the November 2006 issue and the elegant plea by Roger Lowry for a definitive valve amplifier circuit has prompted me to write to you. I have for the last 12 months or so trawled the internet looking for a valve amplifier schematic as well as a source of components. While there is a wealth of information out there, some of it can be downright misleading. I purchased your DVD-ROM containing all the RTV&H articles just so that I could evaluate the September 1955 Playmaster design as it is, after all, a derivative of the classic Mullard 5-20. I have come very close to building one after ascertaining that all transformers are available locally at “reasonable pricing” (Evatco Hammond transformers). Please resurrect Murray valve amplifier In the early 1960s, Cyril Murray at Sydney University published an amplifier design that was different – high performance (distortion of less than 0.02% under class A1) with no overall feedback. It could be used without an output transformer (with a 500 or 600-ohm speaker). I made several of these in 1964 and they produced music with great clarity and dynamic range (we had no distortion meter). Because the 600-ohm speaker had so many windings, the combination was extremely efficient and a 12W amplifier was capable of filling a small hall full of people without any sign of distortion. If you decide on a new valve amplifier design, don’t bother with ultra-linear or single-ended triodes (there are plenty of good designs already) but give Murray’s amplifier a good look. Because it arrived on the scene at the end of the valve era, it slipped under the radar. It was so good that it deserves to be resurrected and I at least would be very keen to build another, perhaps 4  Silicon Chip My interest in electronics goes back to the mid 60s when I started purchasing Electronics Australia. I see that in July 1967, Leo Simpson wrote the article on the Playmaster 118 valve amplifier project, so I would bow to your experience and can understand your reluctance to go back to the “bad old days of valves” when you can improve the on-paper specifications so much more using transistors. I also would ask that you use the Mullard 5-20 as the basis of a new design. It could be a “mono block” design, allowing readers to build one unit at a time. It should use readily available EL34s and I would agree with Roger Lowry that we should replace the EF86 input with a 12AX7. Leo, I think that your quest for perfection in all things electronic may be influencing the type of amplifier the with a bit more power output than the original. Murray wrote two articles on the amplifier in Proceedings of the IRE (Aust.) in March 1960: p129-133 (measurement) and 134-137 (design). There are a couple of websites that mention Murray’s amplifier. I hope you can do something on this design, as it was a real breakthrough at the time. Mick Carrick, via email. Comment: there were a number of high-quality output transformerless designs produced in the 1960s which were essentially single-ended push-pull circuits with an output capacitor coupling to a 600-ohm loudspeaker. We could take the same option today but instead of using a high-impedance speaker, we could perhaps use a quality line output transformer to drive a conventional low-impedance loudspeaker. Incidentally, the 600-ohm speaker was not efficient just because of the high number of turns. Speakers in those days tended to be more efficient anyway because amplifier output power was usually limited. average reader would want to or could afford to build. Let’s put a peg in the ground and start with a more modest 20-30W per channel with an updated “5-20”; perhaps it should be a “4-20” as we would not require a valve rectifier. Andrew Prest, via email. Nested feedback plus automatic bias I would like to congratulate you guys for even considering a valve amplifier project and I do agree that the cost can be very high (transformers, etc). I am glad Roger Lowry (Mailbag, November 2006) did request one though and I agree with his recommendations in the specifications. I have been considering building such an amplifier for a long time as well. Such an amplifier would certainly require lots of nested negative feedback with perhaps push-pull (parallel) EL34s (6CA7) in the output stage, a 12AU7 phase-splitter and 12AX7 voltage amplifiers, plus (due to availability) toroidal transformers, etc. It would also have to be aesthetically pleasing as well. This amplifier would also require some form of automatic bias control to compensate for valve aging. Such a design would appeal to many sensible constructors as the radical “non-feedback golden-eared fringe” has coloured many peoples’ opinions, to the detriment of valve amplifiers in general. Greg Johnson, Cooma, NSW. Is .01% THD too low? Thanks for airing your thoughts Leo, in the Publisher’s Letter in the November 2006 issue, on the design of a valve amplifier. I can see your point siliconchip.com.au Please don’t do a valve amplifier Please, please, don’t sacrifice the interests of the vast majority of your subscribers and readers to waste the limited resources of Australia’s only remaining general electronics magazine on designing and developing a “high-end” valve amplifier. First, as you correctly anticipate, extremely few among your readers would build it. However, that alone is not reason enough to dump the idea. The BIG reason to dump the idea is that the world of audio electronics is currently saturated with valve amplifier designs. Those few readers who genuinely intend to spend the vast sums required to experience the valve sound have many sources for excellent valve designs. Apart from all the information available on the internet, there is the current US publication “Audio Express” (audioXpress.com) which has an innovative valve amplifier project (up to 250 watts RMS, believe it or not) in every issue. From the same publisher came the widely known and highly regarded “Glass Audio”, now discontinued but back issues are available on CD from their that there is little value in putting in a lot of time and effort into something that would possibly not have a lot of appeal and your request for a show of hands to see if it is worthwhile is a very good idea. I have made a few amplifiers over the past six years, my first being the amplifier designed by Mr Tean Tan in Electronics Australia in the Sept/ Oct 1992 issues. I and others who have listened to it are impressed with its performance. This design is very quiet with just a little hiss, only noticeable with your ear up against the loudspeaker. My second effort was the Playmaster No.5, described in Radio TV & Hobbies in June 1952, using 2A3 valves. Those 2A3 valves look very impressive. This amplifier also sounds very good but is a little noisier than the previous unit. The last unit I built was the Mudlark design, featured in the August & September 2005 issues of SILICON CHIP. siliconchip.com.au website at audioXpress.com. Every imaginable valve audio amplifier, including many with detailed construction articles, is also available through this same website. I am not anti-valve or anti-analog. I own a number of valve amplifiers which I do listen to from time to time. I have a very large collection of LPs and a large collection of turntables. So please, dear Editor, give us a class-A high-end, 50-60W per channel solid-state amplifier to showcase the genius of SILICON CHIP’s audio designers. Apart from its usefulness as a hyper-low distortion general amplifier for those who really appreciate the very best, it would be brilliant for driving highend tweeters and midrange drivers in higher-power multi-amped systems with electronic crossovers. Come on all you sensible SILICON CHIP subscribers and readers who are serious music lovers, write to the Editor to stop this crazy push for more valve audio amplifier designs in SILICON CHIP when the world of DIY audio is already awash with them. Otto S. Hoolhorst, Brisbane, Qld. Leo – on your comments regarding distortion of 0.01%: is this level of distortion discernible from 0.1%? Can we really hear that difference? I think the rest of your specifications would be easily achievable. Please accept this email as a definite YES for a new project. Keith Columbine, via email. Comment: perhaps we are setting the bar a bit high by mentioning .01% but we also feel that the amplifier should not degrade the signal quality from a CD player, etc. Is such a low figure discernible? Yes, mainly because such a low figure for harmonic distortion also means very low intermodulation distortion. Edison’s alkaline battery Edison’s “alkaline battery” is nowadays generally called the nickel-iron cell. These rugged batteries seemingly Atmel’s AVR, from JED in Australia JED has designed a range of single board computers and modules as a way of using the AVR without SMT board design The AVR570 module (above) is a way of using an ATmega128 CPU on a user base board without having to lay out the intricate, surface-mounted surrounds of the CPU, and then having to manufacture your board on an SMT robot line. Instead you simply layout a square for four 0.1” spaced socket strips and plug in our pre-tested module. The module has the crystal, resetter, AVR-ISP programming header (and an optional JTAG ICE pad), as well as programming signal switching. For a little extra, we load a DS1305 RTC, crystal and Li battery underneath, which uses SPI and port G. See JED’s www site for a datasheet. AVR573 Single Board Computer This board uses the AVR570 module and adds 20 An./Dig. inputs, 12 FET outputs, LCD/ Kbd, 2xRS232, 1xRS485, 1-Wire, power reg. etc. See www.jedmicro.com.au/avr.htm $330 PC-PROM Programmer This programmer plugs into a PC printer port and reads, writes and edits any 28 or 32-pin PROM. Comes with plug-pack, cable and software. Also available is a multi-PROM UV eraser with timer, and a 32/32 PLCC converter. JED Microprocessors Pty Ltd 173 Boronia Rd, Boronia, Victoria, 3155 Ph. 03 9762 3588, Fax 03 9762 5499 www.jedmicro.com.au January 2007  5 Mailbag: continued trical systems, the lead-acid cell is simply the only choice. Bear Stanley, Thereon, Qld. Comment: older readers will recognise N-I cells as NiFe cells. Fake battery-less torch My wife recently returned from the local $2 shop with a new emergency torch for the car. This was the “Environment-protective torch for the 21st century”. It claimed that it was to be used for emergency purposes because it didn’t rely on batteries – simply shake the torch and it would charge it. I could see what appeared to be a magnet that would slide through a coil in the body of the torch and a small circuit board under the switch. Intrigued about how efficient the torch was, I disassembled it to see what was inside. Surprise, surprise! The white high-intensity LED was connected via the switch to two CR2016 3V lithium coin cells. The ends of the coil were un-terminated; just wrapped around the batteries. There were no components on the last forever – old ex-railroad N-I cells can be easily restored to use, even after a hundred years of sitting idle. The thing not mentioned in your article was that the N-I cell is one of the least efficient of all wet cell designs- requiring from 1.4 to 1.5 times the delivered Ah to recharge. Even a nickel-cadmium (wet) cell only requires 1.25 times capacity to Hydrogen booster is a con circuit board and the “magnet” was just a lump of iron! The whole thing is a technology fake. So don’t be taken in by these torches, especially if you think it’s always going to work in an emergency. There is, however an upside if you want a couple of cheap CR2016 lithium cells and a high-intensity white LED for around four to five dollars. Roger Forsey, Southbank, Vic. recharge. On the other hand, a welldesigned modern lead-acid cell, such as the sealed Sonnenschein gel/SLA will require only 1.05 times delivered capacity to fully recharge. Heavy though it is, so far there is no competition in efficiency to the lead-acid cell; nothing else even comes close. In the most critical uses, like prime movers and alternative elec- I read the letter from J. S., of Geelong (Ask SILICON CHIP, October 2006) with amusement. I am a fully qualified auto electrician with 20 years’ experience. The hydrogen booster is typical of those schemes to extract as much money as possible from those who don’t understand how things work! My other favourite is the two shaped magnets (which look not unlike the ferrite beads we use to prevent RF interference) which are clamped onto the fuel line of the vehicle and which promise to increase the magnetic flux and so increase the power output of the fuel flowing through the pipe. Again, nothing but a con! Dave Sargent, via email. Hydrogen is not a catalyst I have been buying your magazine for a number of years and think you do a really good job. You manage to research and compile an extremely wide field so as to keep things interesting without repeating yourselves. The circuit diagrams and explanations you publish are informative and best of all easy to follow. Home to over 180,000 products Where all the leading brands live GO TO 6  Silicon Chip www.rsaustralia.com RS213SC International Rectifier 100%C, 50%M. Panasonic 4col. Reliable • Simple siliconchip.com.au SMD soldering is more convenient The UHF prescaler in the October 2006 issue is much appreciated. I have recently changed to SMD as much as possible for home projects, because they are more convenient than leaded components. Bending leads, stuffing rows of them through pairs of holes, soldering, then finding the best approach angles for clipping a forest of leads was a pain. SMD ICs are just so fast to solder; eg, with a 44-pin PLCC the steps are: (a) Apply a run of no-clean gel flux, by syringe, along the four rows of pads. (b) Align the chip with the pads and tack-solder two diagonally opposite leads. (c) Fill the (nib-like) hollow of a Weller C-0551-6 or equivalent iron tip with solder and wipe over the pins of one side. Eleven pins on 0.8mm pitch can be soldered in one second! (d) Repeat for the other three sides. On 1.27mm and 0.8mm pitch devices, there’s rarely need for a pin to be cleaned up. There are claims of success on 0.5mm pitch leads but I From the standard set in your publication I will now assume your staff are able to differentiate between fact and opinion. Now if we can refer to “Ask Silicon Chip” October 2006 letter from (J.S., Geelong, Vic) on a hydrogen booster. How much of your answer is fact and how much is opinion? Here is a quote from Roy McAlister, president of the (American Hydrogen Association: “In fact, introducing a small amount of hydrogen, two to five percent, into internal combustion engines that currently run off gasoline, diesel or natural gas increases the efficiency, improves mileage and reduces pollutants quite remarkably”. Roy is not the only one respected in the scientific community who has been published expounding the virtues of “hydrogen enrichment of fossil fuels”. Your answer to the aforementioned letter seemed to revolve around the efficiency of the process - good thinking on your part but perhaps not the siliconchip.com.au haven’t tried. Similarly, it’ll be interesting to try it on J-leaded devices like IC3 in the UHF prescaler. There’s also an easy way to solder chip resistors and capacitors: take a syringe of solder paste and squirt a little on one pad for each component. Place the components, allowing the paste to help hold them in place. Then hold down each component in turn with tweezers while melting the solder paste. Finally, solder the other ends. Reverting to ordinary solder is quicker at this point. Some hobbyists use toaster ovens or frying pans to solder whole boards at a time but there are serious risks of component damage and rupture of the PC board vias (barrel separation) due to differential expansion. Bottom preheat to 150°C followed by hot air on top would be safer. My 50-year-old eyes benefit greatly from a magnifier lamp. While electronics suppliers have them, a large one from a hardware store serves very well. For handling, skidding the board around on a cheap conductive mat works OK for me, when doing just a couple of boards. Erik Christiansen, via email. whole story. The principle of hydrogen enrichment is to use hydrogen as a catalyst. In a nutshell, this quote from a book by Michael A. Peavey, page 175: “This is because hydrogen breaks down larger hydrocarbon molecules, creating a larger surface-to-volume ratio and allowing oxygen to more completely burn the components”. You are right in assuming the process of dissociation is not 100% but the point is that it makes the fuel burn faster and cleaner (recognised scientific fact). Eric Basill, via email. Comment: Sorry Eric, anyone who thinks hydrogen is a catalyst is wrong. By definition, a catalyst is a substance which accelerates a chemical reaction without itself being consumed by that reaction. Nor does hydrogen break down hydrocarbon molecules or lead to more complete combustion of hydrocarbons. You might have seen it in SC a book but it is mumbo-jumbo. Want a real speed controller kit? If you need to control 12 or 24 volt DC motors and want a speed controller that will easily handle 30 amps, then this is the kit for you. This controller allows you to vary the speed of DC motors from 0 to 100%. It is also ideal for controlling loads such as incandescent/halogen lamps and heating elements. This kit makes a great controller for use on small electric vehicle projects, such as electrically assisted bikes and go-carts. We have tested it to over 30 amps without problems—it barely gets warm! Item code: SPEEDCON. We also have solar maximiser kits, Luxeon LEDs, and lots of interesting products and publications. Go to shop.ata.org.au or call us on (03)9639 1500. Serial-to-TCP/IP Converters from TRUSYS Trusys BF-430 & BF-450 universal serial device servers allow your industrial serial devices – such as PLCs, flow meters, gas meters, CNC machines and biometric identification card readers – to be monitored from your network. They support web management & firmware upgrade, while PPPoE & DDNS protocol allows Internet connection without static IP. Event alarm trigger is supported using e-mail & SMS (Short Message Service) to do real-time management for your system. Applications: ] Factory automation ] Hospital automation ] PLC instrument control ] Access control and security ] Time recording system For more information, call, fax, email or visit our website! TRUSYS 95 McCanns Rd Mt Duneed Vic 3216 Tel: 0428 282 222 Fax: 03 5264 1275 Email: sales<at>trusys.com.au www.trusys.com.au January 2007  7 Yokogawa’s 10th generation digital oscilloscopes offer GHz bandwidth for less money than the competition – and they won’t hog your desktop, either! By PETER SMITH Yokogawa signalXplorer DL9000 Series Digital Oscilloscopes T HE RECENTLY released DL9000 series is the latest in compact digital oscilloscopes from Yokogawa, boasting sampling rates of up to 10GS/s (gigasamples per second) at bandwidths of 1-1.5GHz. According to Yokogawa, conventional products in this bandwidth range have been desktop-sized and quite expensive. Not so the DL9000 series, which packs an impressive array of features into a package measuring 18cm deep and weighing in at only 6.5kg. All four models in the series have four input channels and 213mm highresolution colour LCDs. The DL9140 & DL9140L feature an analog bandwidth of 1GHz with a maximum sampling rate of 5GS/s (2-channel mode) or 2.5GS/s (4-channel mode). 8  Silicon Chip The DL9240 & DL9240L models extend the bandwidth to 1.5GHz and increase the maximum sampling rate to 10GS/s (2-channel mode) or 5GS/s (4-channel mode). Record length for the DL9140 & DL9240 is 2.5M words/channel maximum, whereas the “L” suffixed versions stretch this to a whopping 6.25M words/channel. A custom signal-processing engine pumps data into memory at a maximum effective rate of 2.5 million waveforms per second per channel on the 500ps/div range. First look We test-drove the DL9140 model. We were immediately impressed with the large colour XGA (1024×768 pixels) display, which is bright and razor sharp and would be difficult to better. Considering its quadruple inputs and raft of measurement options, the front panel is relatively uncluttered and doesn’t look intimidating. As with all instruments of this complexity, selections are made and parameters altered via a hierarchical, “soft-key” menu system. Pressing a “top level” function key in the blue-paneled area brings up the relevant on-screen soft menu, which appears as a single bar down the right side of the display to align with the column of unmarked selection keys. The soft menus rarely extend beyond two levels, so once familiar with the instrument’s capabilities, it’s surprising easy to drive. siliconchip.com.au Rotary dials provide for rapid vertical sensitivity and horizontal timebase changes, while the function of the large dial (at panel top) and its associated navigation keys vary according to the last selected menu. A built-in context-sensitive help system is an indispensable part of the overall package. Can’t remember how the options in the “Accumulate” menu work? Easy, just press the HELP button followed by the ACCUM button to bring up the relevant page of the manual! Going deep Deep memory and high-speed sampling coupled with very low latency are undoubtedly the DL9000 series’ strongest points. When record length is less than memory depth, acquisition memory is divided into partitions. Successive records are captured into these partitions (called history memory) with very low latency. In the fastest acquisition mode, up to 1600 records can be captured into history memory with a dead time of only 400ns between acquisitions. Repetitive waveforms can be acquired using the slower accumulate mode, which captures up to 2000 records. Waveforms in history memory can be examined individually, or the sequence replayed in forward or reverse direction at variable speed. A conditional search function allows you to track down signal events based on measurement limits, which can even be correlated between channels. Acquired waveforms can be accumulated over a user-defined period and displayed on-screen using an intensity or colour-grading scheme (called “Dot Density Display”). This works in real time or can be applied retrospectively to history memory. The result is an immediate indication of the frequency and signal-to-noise ratio of signal perturbations. Finding the needle All digital scopes these days include “zoom” capabilities to allow faster review and analysis of selected portions of acquisition memory after signal capture. In zoom mode, the display divides horizontally to include a second expanded view of a portion of the waveform selected in the normal view. The zoom window can be manually scrolled through acquisition memory siliconchip.com.au One of the DL9000 series’ many useful features is its easy-to-drive zoom mode with search. Zoom mode can be brought to bear on history memory (ie, after signal capture) and will help to find that waveform anomaly in quick time. In this example, the “runt” pulse was easy to spot in the normal waveform display but of course this won’t always be the case! (including history memory) using the large rotary knob and various soft controls. Importantly, Yokogawa have included a series of powerful search options that can help to quickly pinpoint the area of interest. Advanced analyses Two additional panes can be opened beneath the normal oscilloscope traces for display of analysis waveforms or XY waveforms. The histogram and trend analysis features are of particular interest and offer a whole new perspective on signal visualisation. For example, signal jitter can be revealed using a time histogram, whereas noise on DC signals can be revealed using a voltage histogram. Trend analysis would typically be used to view the fluctuations of a selected parameter over the long term. Alternatively, the analysis panes can display FFT (Fast-Fourier Transform) calculated waveforms of up to 250k points each using the chosen source channel, centre frequency and frequency span. Math & filters In addition to the four input channel traces, up to eight math traces can be defined and displayed. Functions include filtering, addition, subtraction, integration, “edge count” and “rotary count”. Basic arithmetic functions are performed in hardware and so the results can be displayed in real time. 200MHz & 20MHz analog low-pass filters and a series of selectable digital low-pass filters are also available and again, these operate in real time so they don’t slow down the signal acquisition rate. If the inbuilt math functions don’t do what you want, then the optional “MATLAB tool kit” software can be used to control your scope from within MATLAB or transfer data to MATLAB via the GPIB, USB or Ethernet interfaces. Statistics & other measurements A comprehensive list of signal measurements can be applied to any scope trace. This includes a raft of statistical functions such as maximum, minimum, average, standard deviation, etc. Statistics can be generated on a continual, cycle or historical basis and displayed in the waveform area or at the right side of the screen if the soft-key menu is inactive. Other goodies Go/No Go testing can be set up using January 2007  9 DL9000 Series Highlights • • • • • • • • • • Input channels: 4 Analog bandwidth: 1GHz (DL9140/DL9140L); 1.5GHz (DL9240/ DL9240L) Sampling rate (max): 5 GS/s (2 channels); 2.5 GS/s (4 channels, DL9140/DL9140L); 10 GS/s (2 channels); 5 GS/s (4 channels, DL9240/ DL9240L) Record length (max): 2.5 M word/channel (DL9140/DL9240); 6.25 M word/channel (DL9140L/DL9240L) Fast acquisition rate: 2.5M waveforms/s/ch (max) Vertical sensitivity: 2mV/div Vertical resolution: 8-bit Sweep sensitivity (max): 500ps/div History memory function: Review & analyse up to 2000 of the most recent waveforms Compact & lightweight: 180mm depth, 6.5kg weight. for those that wish to develop custom remote control applications or plug-ins. Applications So where would you use a scope with this level of performance? Here’s a short list of applications suggested by Yokogawa: • Design and evaluation of devices embedded in cellular phones, flatscreen televisions, etc. • Confirming the operation of devices such as FPGAs (Field-Programmable Gate Arrays) and ASICs (ApplicationSpecific Integrated Circuits). • Observation of control signals from microcontrollers and the like, as well as debugging of control firmware. • Troubleshooting and evaluation of communications bus data. Last word a range of user-defined rules, with the results signalled via a TTL-compatible output at the rear of the box. More complex tests can be constructed using “masks” and the free Mask Editor software. Specialised data analysis is also available for the I2C and SPI data buses by ordering the “/F5” option with the scope. This option provides sophisticated triggering on bus states, device addresses, etc, and includes search capabilities. able work, the optional internal 30GB HDD would be a good choice. A printer, mouse and keyboard can also be connected to the front-panel USB ports. The keyboard could be useful for file naming and waveform annotation when working with large sets of data, although we didn’t try this configuration. Using built-in functions, an optional Ethernet interface allows data to be stored and waveforms printed on a network running file and printer sharing. An optional built-in thermal printer is available for portable work. Direct PC connectivity is also possible via a third USB port on the rear of the unit, which is supplied as standard equipment. However, to control the instrument from your PC you’ll need to purchase the optional “Xviewer” software utility. Xviewer also allows you to view saved waveform data and convert binary data to ASCII for use in other applications. A math edition of this software can calculate up to 10 additional waveforms based on saved data and do FFT calculations using up to two million points. A free DLL library is available The triggering options for these instruments are extremely comprehensive and command their own 22-page document – which, by the way, can be downloaded from the Yokogawa website at www.yokogawa.com/tm for those interested. We’re not even going to attempt to describe them in this short review! Product flyers can be obtained from the abovementioned website. Unfortunately, it seems that it’s not possible to download a copy of the user’s manual unless you already own the product. You’ll find the people at Trio Smartcal (the Australian distributors) much more obliging. Check out their website at www.trioelectrix.com.au or phone 1300 853 407 to organise a demonstration. Issues Getting Dog-Eared? REAL VALUE AT Connectivity Getting data in and out of early digital scopes used to be problematic, with floppy drives sometimes being the only option. Thankfully, diskettes have gone the way of the dinosaur and in the case of the DL9000 series, been replaced with dual up-front USB connectors for flash memory as well as dual PCMCIA slots for memory/hard disk drive connection. A total of 32MB of flash memory is available internally for storing waveforms and front-panel settings. An external USB flash memory dongle will instantly improve this rather small offering. For heavy-duty port- Prices Prices for the DL9140 in basic form start at under $15,000 + GST. All models are supplied with four 500MHz passive probes. To utilise the full 1.5GHz bandwidth, you’ll need to order one or more of the optional 2.5GHz active probes. 500MHz differential and 100MHz current probes are SC also offered as optional extras. Keep your copies safe with these handy binders. $13.95 PLUS P & P Available Aust, only. Price: $A13.95 plus $7 p&p per order (includes GST). Just fill in and mail the handy order form in this issue; or fax (02) 9939 2648; or call (02) 9939 3295 and quote your credit card number. 10  Silicon Chip siliconchip.com.au Using fingerprints to unlock doors . . . BioLock No keys, no cards, no pins . . . but it’s very secure! H ave you ever fumbled for keys in the dark to open the front door? Ever lost your keys and had to scramble around finding “the spare”, getting a new one cut, etc etc? Ever locked your keys inside the house? Ever had your keys stolen and thought the worst? None of these need ever happen again if you fit a Biolock – because you won’t even have a key to fumble, lose, have stolen or locked inside! “So what’s gonna keep the bad guys out,” you’re thinking. No key means no lock, right? No lock means no security, right? Actually, wrong on both counts! The siliconchip.com.au idea is to get rid of that old-fashioned (and in many cases low security) lock and replace it with something that will let you (or anyone else you allow) in and keep everyone else out – with excellent security, A potted history of locks The oldest known lock, estimated to be 4,000 years old, was found by archeologists in the Khorsabad palace ruins near Nineveh. It was a forerunner to a pin tumbler type of lock and a common Egyptian lock for the time. by Ross Tester This lock worked using a large wooden bolt to secure a door, which had a slot with several holes in its upper surface. The holes were filled with wooden pegs that prevented the bolt from being opened. The first serious attempt to improve the security of the lock was made in 1778 in England, when Robert Barron patented a double-acting tumbler lock. Then in 1784, Joseph Bramah patented the safety lock. Bramah’s lock was considered unpickable. A name almost synonymous with locks, Linus Yale Sr, invented a pintumbler lock in 1848. His son, Linus Yale Jr, improved January 2007  11 Here’s what you get in the Biolock kit: the Biolock scanner (bottom right, with its mounting plate below); the electric strike immediately above that and plugpack power supply above that again; secure I/O board in the centre with its surface-mounting case at left, the cabling you will need at the top of the picture, rawl plugs and screws and finally, the mounting and setting-up instructions. The whole lot retails for less than $800. upon his lock using a smaller, flat key with serrated edges that is the basis of modern pin-tumbler locks and also patented a cylinder pin-tumbler lock (the basic lock as we know it today) in 1861. Yale further invented the modern combination lock in 1862. (From “The History of Locks” [http:// inventors.about.com/library/inventors/bllock.htm]) As you can see, locks as we know them have been around for quite a while. And for just as long, crooks have been trying to defe at them – they pick them, they force them, they jemmy them, they cut them out of the door (according to the movies, almost always with a sub-machine gun!), they steal keys, they force people with keys to open them . . . Hence the adage, “locks are only to 12  Silicon Chip keep honest people out”. Don’t you think it’s about time things changed a little, putting the odds back in the honest people’s favour? If, at the same time, we were able to dramatically increase convenience and flexibility, that would be a real bonus. which is separate to “the lock” itself and is fitted to the door jamb or post. We specifically mention these two components because they are essential to the operation of this electronic system. There are other parts, of course but are not important to this story. Parts of a lock Enter the Biolock When we think of “a lock” we generally think of a lot more than what is actually the lock. In fact, the lock is only a small part of “the lock” – albeit a very important part. It’s the bit which prevents or allows (depending on how it is set) the device as a whole from operating. Other parts of “the lock” to note are the bolt – the bit that moves in and out of the door, engaging the strike (sometimes known as a latch plate), Back in our January 2001 issue , we introduced the subject of biorecognition – checking to see if you really is you. At the end of the article, author Jon Reid said “Finger scanning equipment can be purchased commercially for approximately $2000 to $3000 . . .” We are very pleased to say that five years on, finger scanning equipment can be purchased for way less. In fact, Jon Reid’s company, Bisiliconchip.com.au Here’s the electric strike which replaces the strike currently fitted into the door jamb. Inset top left is the actual “strike” – at rest, (ie, unpowered), the vertical blade (arrowed) is locked in position so it can capture the bolt in the lock, thereby locking the door. When power is applied, this blade is free to move so a pull on the door will allow the bolt to push the blade out of the way, thus opening the door. orecognition Systems, has available a complete finger scanning kit to install in any home, office, factory, club . . . and electronically control who can come in and who can’t . . . for less than $800. It’s called the Biolock, and that’s the system we are looking at in detail here. For a business with access control problems, $800 is chicken feed, especially when you consider what you get and the control it gives (they’d probably spend that much in keys!). However, $800 is still significant for the average homeowner. But have you priced having a decent lock installation recently? We have: SILICON CHIP moved offices last year! The bill was over $400 for a single door, quality double deadlatch and ten keys – so all of a sudden a Biolock kit, with all of its advantages, isn’t exactly over-the-top! The best part of all is that the Biolock kit is very easy to install because it uses the existing lock – the only change you have to make is to install is the electric “strike” in place of the current one. Eh? Use the existing lock? Wait a minute! Doesn’t that defeat the whole purpose? Why install a Biolock and leave the existing lock in place? The answer actually highlights some of the features of the Biolock. First, the system is failsafe. In an emergency, instant egress is possible by using the existing handle. And in the event of a computer or hardware failure, or blackout (which would disable the electric strike), a key can be used to siliconchip.com.au open the door. Second, in the event of an injury which precludes someone placing their finger on the scanner (a broken hand/ arm in full plaster, perhaps?), they can still be given keys to enter/exit in the traditional way. Third, if you happen to have a building owned by someone else and it has a master key system, there is often a condition of the lease or occupancy that the top-level keyholder has access via a grand master key, which may be used for inspection, maintenance, etc. Clearly it is difficult, if not impossible, to arrange scanning each person who may at some time require access – so their master key will still work. We’re sure you’ll think of other reasons why you would still want traditional (keyed) access – the Biolock gives you the best of both worlds. Keyless/cardless/pinless operation Having said all that, the Biolock is intended for virtually keyless operation. Automatically, that eliminates the problems of lost keys (and security keys, as used by a company, cost a lot more to replace than your average house key!). It also stops key and/or card-swapping between keyholders and/or those who you do not want to have a right to enter. Even in a “secure” system such as a building with RFID, swipe cards, keypads/pins, etc, swapping can be a major problem for building management – especially in an access-controlled system with various keys, cards etc controlling which doors can be entered. Because the Biolock system doesn’t have a keypad, card reader, RFID reader, etc, this simply cannot happen. The only way an intruder can enter is to “tailgate” a legitimate user – and that’s a problem with every controlled entry system except those with singleperson turnstiles or airlocks (or armed guards!). As you might have guessed from the above, Biolocks can be installed on every external door and on any internal door requiring access control and are (or can be) all linked to a common computer system. Reading the fingerprint It’s the stuff of spy movies and thriller TV series; a crook manages to capture a fingerprint of a legitimate user and then makes a (usually latex) “cast” of it, either using that in fingerprint recognition systems or leaving “prints” around to drop the unfortunate right in it. Maybe, one day, that will be possible but the Biolock goes a long, long way to ensure it won’t be today (or tomorrow). The fingerprint is not actually read on the surface of the skin but deep down in the epedermis. That means that surface cuts and scratches won’t lock you out of the system; by the same token it also means that attempts to The old and the new: the original “strike” at left (just a hole cut in the steel frame!) with the new strike position marked out and the electric strike installed in the door jamb, along with the old strike it replaced. It is significantly larger and being fitted into a steel-frame door, required a fair bit of “surgery” to the jamb. Fortunately, it’s hidden once the door closes (and I fully intend to fix up the rough edges. One day. Manana. Maybe). January 2007  13 beat it using copies or fakes will be unsuccessful. That other, rather more gruesome thriller movie “method” – cutting off someone’s finger so you have the “real thing” – is also highly unlikely to succeed, given the fact that there would be no blood flow in the finger concerned. Knowing that, I’m sure you can sleep a lot easier at night! Note that the Biolock system does not store fingerprints per se – at least not in any retreivable format. That would contravene privacy laws. Instead, the system compares the digital information of a known fingerprint scan with that obtained at the time entry is required. The system in detail The Biolock system has three major components: (1) The Biolock scanner This small (75 x 105 x 27mm) waterproof (IP65) unit is designed to fix on a wall or jamb close to the entry point. As far as the user is concerned, it has just two parts – a scanner “window” about 10mm square and three LEDs to show system status. A blue LED indicates the sensor is ready to read a fingerprint, a green LED shows identity acceptance while a red LED shows identity rejection. Inside the scanner, there is of course the electronics to make it all happen. (2) The door strike The strike is the part of the lock which mounts on the door jamb and “catches” the bolt, locking the door. Every door with any sort of lock or catch has a strike – in most cases it has an angled plate which the springloaded bolt rides up as the door closes and a recess which catches the bolt as it springs back out, holding the door closed. The closed door might be automatically locked if it has that type of lock mechanism; it might require manual locking (eg, with a snib) or it may not have a lock at all but can be opened by simply turning a handle (which pulls the bolt back into the lock/door). The electric door strike in the Biolock system is, for all intents and purposes, exactly the same as a bogstandard strike in its normal (unpowered) state -hence the ability for the system to use the existing door lock in the normal way. But when it is powered, a solenoid pulls in releasing the door strike so it 14  Silicon Chip The Biolock unit can be installed in any convenient location, as long as the surface is pretty flat (or packed out to be flat). Naturally, it should be close to the door being controlled. The cable goes through the wall so security of the system is maintained. can move out of the way – it’s actually pushed out of the way by the bolt. So if the strike is energised and the door is pulled, it will open, even if the bolt itself is locked closed. (3) The computer and secure I/O interface A computer is required to run the Biolock – it stores the information on legitimate users and also, with the software included in the system, enables a vast amount of information to be stored about entry and egress, by whom, and so on. It does this over a standard TCP/IP network and you can set the address anywhere between 192.168.0.1 and 192.168.0.254 (excluding .210). So if you already have a computer network set up, even a very big one, you can find an address for the Biolock. The interface is a small PC board which is used to control secure opening and closing of electric strikes and access control for doors. It includes a relay to handle the fairly heavy (~800mA) current demand of the strike. Included in the kit is a small (65 x 37 x 25mm) wall-mounting ABS case which the interface board fits into perfectly, along with the required interface cables. Installation Arguably the hardest part of installation will be the electric strike, because it is significantly larger than any “ordinary” strike you are likely to see. With a traditional wooden door jamb, though, it’s only a matter of marking out and cutting to the depth required, as you would for the traditional type you’re replacing. The main thing to watch is that the strike blade lines up with the edge of the current strike recess, both in the vertical and horizontal planes. Of course, if your door currently rattles in the wind or has to be slammed to close, you could use this opportunity to slightly adjust the strike position for a better fit. If your is outward-opening, the strike will have to be installed upside down – but that’s not a big deal. Steel-frame doors, as are much more commonly used in industrial/commercial buildings and flats/units, are a bit more of a dilemma. The chances are very high that you will need an angle grinder and a selection of tools to perform surgery on the door frame to fit the strike. Indeed, many steel-frames are also filled with concrete so you may even need to cold-chisel some of that away and perhaps fit the strike into the concrete with rawl plugs. Don’t forget that you need to run the “speaker wire” figure-8 cable to the strike. The wires are polarised so you can work out which is positive and negative at the other end (red is +!). The wires connect to the strike via a pair of screw terminals. Don’t take the pre-fitted diode out – it protects the circuitry from the spike generated as the solenoid is released. The Scanner This obviously needs to go close to the door in question but doesn’t have to be right up on it. Choose a location that is preferably out of the weather (even though the Biolock scanner is IP65 rated, so it will stand direct rain and even a low-pressure hose). For security, the wiring should go siliconchip.com.au straight through the wall or surface to which it is attached so you will also need to take that into account. The wall or surface also needs to be flat – if you must, you can pack out so the bracket which holds the scanner is flat. The bracket is mounted first, then the scanner attaches to the bracket. If it seems we are glossing over this section, we are: the instructions with the Biolock are much more detailed (even though they start with the scanner then fit the strike!). The Secure I/O This is a small PC board which comes with a surface-mounting ABS box, designed to mount in any convenient position inside the building. Installation here is as simple as connecting the mounting the box, connecting the various (supplied) cables to the PC board and placing it inside the box. Finally, it is all screwed together and hardware installation is virtually complete. Connecting it all up We mentioned before that the system requires a computer (and a TCP/ IP computer network) to operate. That network can be as simple as the Biolock, computer (with network card – and they are dirt cheap these days) and connecting cat5 cable - or it can operate over an already-installed network. If you have an existing network with a convenient RJ45 socket, you’re laughing. Just plug in the cable from the secure I/O board. We mentioned before that it must be configured to an IP address in the range 192.168.0.1 to 192.168.0.254, excepting 192.168.0.210 (which is the Biolock’s own IP address). Once again, the instructions contain all the information you’re going to need to get the Biolock up and running on your system. BioKey software Included with the kit is a CD-ROM containing BioKey software. This is not only the “driving” software for the system, it’s also the way you “enrol” legitimate users and set up the access rules for them and the building. The system tells you when you have an acceptable reading as new users are “enrolled”; otherwise an error will be flagged and a new reading taken. In a multiple Biolock system, as each Biolock has its own IP address it can be set up individually, allowing or denying access as required for that particular door. You can also set up times that certain individuals can access areas (eg, deny access after hours or at weekends). The software also allows you set the level of security from very weak (where it will give a false acceptance 1 time in 5, through to very strong – 1 time in 100,000. There are trade-offs in taking too high a level are that legitimate users may experience too many rejections. Default level (normal) is 1 in 500. You have wireless? Because each Biolock is an IP device, you can add wireless to it and avoid running cables (just as you would in any wireless network). This of course applies to home use just as much as business. Other software Biorecognition Systems have a range of other add-on software products to expand the Biolock’s capabilities. Of particular note is the BioTime Time and Attendance software which can eliminate time cards or clocks. They also have more powerful access control software for higher security applications. More info? Visit the Biorecognition website at www.brsgrp.com Radio, Television & Hobbies: the COMPLETE archive on DVD YES! NA MORE THA URY ENT QUARTER C NICS O OF ELECTR ! Y R O T IS H This remarkable collection of PDFs covers every issue of R & H, as it was known from the beginning (April 1939 – price sixpence!) right through to the final edition of R, TV & H in March 1965, before it disappeared forever with the change of name to EA. For the first time ever, complete and in one handy DVD, every article and every issue is covered. If you’re an old timer (or even young timer!) into vintage radio, it doesn’t get much more vintage than this. If you’re a student of history, this archive gives an extraordinary insight into the amazing breakthroughs made in radio and electronics technology following the war years. And speaking of the war years, R & H had some of the best propaganda imaginable! Even if you’re just an electronics dabbler, there’s something here to interest you. • Every issue individually archived, by month and year • Complete with index for each year • A must-have for everyone interested in electronics Please note: this archive is in PDF format on DVD for PC. Your computer will need a DVD-ROM or DVD-recorder (not a CD!) and Acrobat Reader V6 (free download) to enable you to view this archive. This DVD is NOT playable through a standard A/V-type DVD player. Exclusive to SILICON CHIP $ ONLY 62 + $ 00 7 P&P HERE’S HOW TO ORDER YOUR COPY: BY PHONE:* (02) 9939 3295 9-4 Mon-Fri * Please have your credit card handy! siliconchip.com.au BY FAX:# (02) 9939 2648 24 Hours 7 Days <at> BY EMAIL:# silchip<at>siliconchip.com.au 24 Hours 7 Days BY MAIL:# PO Box 139, Collaroy NSW 2097 # Don’t forget to include your name, address, phone no and credit card details. BY INTERNET:^ siliconchip.com.au 24 Hours 7 Days ^ You will be prompted for required information SC January 2007  15 SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au By John Clarke & Julian Edgar Using the temperature switch, it’s easy to rig warning lights or alarms for over-high engine or gearbox oil temperatures. In fact, anything’s that hot in the car (with the exception of the exhaust gas and cylinder head) can be monitored. [Ford photo] Temperature Switch A cheap general-purpose adjustable design that can work all the way up to 245°C! T HERE ARE MANY automotive performance applications where you want to turn something on or off on the basis of measured temperature. Radiator cooling fans, over-temperature warning lights or alarms, intercooler or amplifier fans – they all need a cheap and easily-adjusted temperature switch. Temperature switches are available commercially but this build-it-yourself design has some major advantages over normal thermostats and temperature switches. First, it can be adjusted very finely – you can literally set (to Main Features • Adjustable temperature switching from 0°C to 245°C • Double-pole changeover 5A relay contacts • Selectable rising or falling temperature switching • Adjustable hysteresis • Easy to build 22  Silicon Chip the degree) the temperature at which the switch triggers. Second, the hysteresis (ie, the difference between on and off temperatures) is adjustable. That lets you set the system up so that the device you’re switching isn’t constantly cycling at the trigger point. You can set a wide hysteresis to switch something on and off at two widely spaced temperatures, or a low hysteresis to keep tighter control – the choice is yours! Third, the sensor used in this design is good for temperatures up to 245°C. This means you can monitor engine oil or auto transmission oil temperature, or site the sensor near the brakes to trigger cooling sprays. Basically, apart from exhaust gas and cylinder head temperature, you can trigger the switch with anything on the car that’s hot or cold! Finally, you can configure the sensor so that it reacts very quickly to temperature changes. Construction The Temperature Switch is a simple kit to build but you should make one decision before starting construction. Will you be using it to detect a temperature that is rising to the trip point or falling to the trip point? The Temperature Switch can be configured to work either way but if you know which way you’re going, you won’t have to make changes later on. The detection of a rising temperature will be the more common application – for example, turning on a warning light or fans when the temperature gets too high. But if you want something switched on as the temperature falls – for example, activating a warning light when the outside temperature drops below 3°C to warn of the possibility of black ice on the road – then the Temperature Switch needs to be configured for a falling temperature. So what are the changes made for the differing configurations? They’re simple: for rising temperature detection, link LK1 is placed in its “L/H” position (ie, to the left when the board is orientated as shown in Fig.2) and diode D3 is orientated so that its band is closest to the bottom of the board. Conversely, siliconchip.com.au Fig.1: the temperature is monitored using a thermistor, while either op amp IC1a or IC1b drives transistor Q1 and the relay. Trimpot VR1 sets the temperature trigger point. How It Works The temperature is monitored using a thermistor which exhibits a variable resistance with temperature. At high temperatures, the resistance of the thermistor is low, while at lower temperatures its resistance increases. A 1kΩ resistor from the 8V supply feeds current through the thermistor which then produces a voltage which is inversely proportional to temperature. This voltage is filtered using a 100nF capacitor and fed via a 1kΩ resistor to the inverting input (pin 2) of op amp IC1a which is connected as a comparator. The voltage on IC1a’s non-inverting input (pin 3) is by set-point trimpot VR1 via a 10kΩ resistor. When the thermistor voltage at pin 2 is above the voltage set by VR1 at pin 3, IC1a’s output is low. Conversely, when the thermistor voltage is below the voltage on pin 3, IC1a’s output is high (around +8V). Hysteresis has been added to prevent the output of IC1a from oscillating when the inverting input is close to the switching threshold. This hysteresis is provided by trimpot VR2 and diode D3 in series between pins 1 & 3. Trimpot VR2 enables the amount of hysteresis (actually positive feedback) siliconchip.com.au to be adjusted. With low hysteresis, the temperature only has to drop by a small amount for IC1a’s output to switch low again after it has switched high. If VR2 is set for high hysteresis, the temperature must fall by a much larger amount before IC1a’s output switches low again. Diode D3 sets the direction of the hysteresis action. As shown, it provides hysteresis when pin 1 of IC1a goes high. Alternatively, if mounted in the opposite direction, it provides hysteresis when IC1a’s output goes low. Where the circuit is intended to provide a switched output when the temperature goes above a certain value, the diode is installed as shown on the circuit and parts overlay (Fig.2). If you want the switching to occur when the temperature falls below a certain value, diode D3 is reversed. Op amp IC1b is an inverter which provides a signal opposite in polarity to IC1a’s output. When IC1a’s output goes high, IC1b’s output goes low and vice versa. Link LK1 provides the option for driving the relay with a rising temperature (L/H) or a falling temperature (H/L). It selects the output of IC1a or IC1b to drive transistor Q1 which, in turn, drives the relay. Diode D2 is there to quench the reverse voltage that is generated by the collapsing magnetic field of the relay coil each time it is switched off. Power is obtained from the car’s +12V ignition supply via D1 which gives reverse polarity protection. The 10Ω resistor, 100µF capacitor and zener diode ZD1 provide transient protection at the input of regulator REG1. All the circuitry is powered via the 7808 regulator with the exception of the relay, Q1 and LED1 which are driven from the 11.4V supply following D1. Resistor Colour Codes Value 4-Band Code (1%) 5-Band Code (1%) 22kΩ 10kΩ 1.8kΩ 1kΩ 10Ω red red orange brown brown black orange brown brown grey red brown brown black red brown brown black black brown red red black red brown brown black black red brown brown grey black brown brown brown black black brown brown brown black black gold brown January 2007  23 The device turns other devices on or off on the basis of sensed temperature. Its sensor can work over the range of 0°C - 245°C, making it useful for monitoring engine oil, engine coolant and transmission oil temperatures, as well as intercooler and inlet air temperatures. Note that link LK1 (to the left of the relay) must be moved to the H/L position and diode D3 (circled) reversed in orientation if the switch is to trigger on a falling (rather than rising) temperature. Use It To Do This . . . • • • • • • transistor, voltage regulator and electrolytic capacitors. During construction, follow Fig.2 closely to avoid making mistakes. The thermistor is of the “bare” design – ie, it’s not potted in epoxy or mounted inside a brass fitting. If you want temperature detection to occur very quickly (ie, if you want the thermistor to react quickly, even to small temperature variations), the 100 µF 10 µF H/L CT N L/H 10k C ON CN 1.8k 22k 10k 100 µF ON NO + NC CN H/L LK1L/ H K 10k 1k 100nF COM C COM + 10 µF 1k NO NC IC1 LM358 1 K + K 1M A 1N 4148 ZD1 + TO THERMISTOR *D3 10k A K LED1 VR2 REG1 7808 V21+ +12V DNG GND A VR1 1k 10Ω D2 Q1 RELAY 1 1 0 1ra c 5 0 A D1 K H CTI WS ERUTAREP MET to detect a falling temperature, link LK1 is moved to its alternative “H/L” position and diode D3’s orientation is reversed. Easy, huh? When assembling the PC board, be sure to insert the polarised components the correct way around. These parts include the diodes, IC, LED, A *REVERSE D3 IF LINK LK1 IS IN 'H/L' POSITION Fig.2: this layout diagram shows where each of the parts is placed on the PC board. Don’t forget to reverse D3 if link LK1 is in the H/L position. 24  Silicon Chip Operate electric radiator fans Over-temperature warning light or alarm Operate amplifier cooling fans Operate an intercooler water spray or fan Operate a brake cooling water spray Reduce turbo boost when intake air temperature is high thermistor should be left exposed. However, if the reaction speed isn’t so important but durability is, you can pot the thermistor in high-temperature epoxy and mount it in the end of a threaded brass fitting. Either way, the thermistor will need to be connected to a length of shielded single core cable, with the shield (the braid) connecting to the 0V terminal on the PC board. The thermistor isn’t polarised – it can be connected either way around. Insulate the leads of the thermistor using heatshrink tubing so that they cannot short out to each other or to ground. In many cases, the whole thermistor itself can then be covered in heatshrink without slowing its reaction time too much. Testing Once the assembly is complete, it’s a good idea to bench-test the module to make sure it works correctly. To do this, you’ll need to connect the thermistor to the input terminals (remember, braided side of the shielded cable to 0V) and supply power and earth. First, turn VR2 (just above IC1) fully anti-clockwise. Then turn set-point pot VR1 anti-clockwise until the relay siliconchip.com.au The thermistor’s leads should be insulated and then covered in heatshrink tubing so that short circuits can’t occur. If durability in extreme conditions is required (and the sensor doesn’t need to react quickly), it can be potted in high-temperature epoxy and mounted in the end of a threaded brass fitting. clicks and the LED comes on. Because VR1 is a multi-turn pot, you may need to rotate it a number of times before the LED lights. Once the switch has tripped, you can then turn the set-point pot back clockwise just enough to turn off the LED and disengage the relay. Now when you heat the thermistor, the LED should immediately come on and the relay click over; cooling the thermistor should cause the LED and relay to turn off again fairly quickly. Finally, turn VR2 (hysteresis) clockwise a little and you should find that the switch takes longer to turn back off when it is being cooled down after being tripped. Fitting Fitting the Temperature Switch to a car is easy. You need only provide an ignition-switched power supply Fig.3: here is a typical connection set-up, where the Temperature Switch might be monitoring the temperature of an audio amplifier. The relay’s Normally Open (NO) connection is made to ignition-switched +12V, while the adjacent Common terminal is connected to a fan. The other side of the fan is earthed. When the temperature rises to the set-point, the fan is triggered. The setting of the hysteresis pot determines how low the temperature then has to fall before the fan switches off. and earth, and then install the thermistor where you want to sense the temperature. For example, if you are controlling a radiator cooling fan, you could place an electrically-insulated temperature sensor on the top tank of the radiator. Or if you want the Temperature Switch to illuminate a warning light when engine or transmission oil gets excessively hot, you could attach the sensor to the appropriate sump. If you want just the warning light function, you can remotely mount a high-intensity LED within your line of sight – just extend the wires that connect the LED to the PC board, making sure that you keep the LED polarity correct. If you want to turn a device on and off with the temperature switch, you can use the relay’s Normally Open (NO) and Common contacts. Fig.3 shows these connections. The relay’s contacts are rated to 5A – for currents higher than this, use the on-board Table 1: Setting The Trip Point Temperature °C Rt Vt °C Rt Vt °C Rt Vt 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 33,944.034 26,120.042 20,286.407 15,894.535 12,557.604 10,000.00 8023.382 6483.660 5275.206 4319.920 3559.575 2950.420 2459.334 2061.059 1736.202 1469.774 1250.116 7.771 7.705 7.624 7.526 7.410 7.273 7.113 6.931 6.725 6.496 6.245 5.975 5.687 5.387 5.076 4.761 4.445 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 1068.105 916.558 789.791 683.278 593.399 517.244 452.462 397.143 349.731 308.953 273.760 243.287 216.818 193.755 173.601 155.938 140.416 4.132 3.826 3.530 3.247 2.979 2.727 2.492 2.274 2.073 1.888 1.719 1.565 1.425 1.298 1.183 1.079 0.985 170 175 180 185 190 195 200 205 210 215 220 225 230 235 240 245 126.739 114.656 103.954 94.454 85.999 78.458 71.718 65.679 60.259 55.384 50.991 47.023 43.435 40.183 37.231 34.547 0.900 0.823 0.753 0.690 0.634 0.582 0.535 0.493 0.455 0.420 0.388 0.359 0.333 0.309 0.287 0.267 You can use this table to set the trip point for the temperature switch, where the temperature is shown in the lefthand column and the voltage required to be on the middle pin of the set-point pot (VR1) is shown on the righthand side. For example, if you want the switch to trip at 145°C, the pot will need to be turned until the measured voltage is 1.425V. siliconchip.com.au January 2007  25 Parts List The temperature switch can be used to operate electric radiator fans and you can adjust the difference between the switch-on and switch-off temperatures. With high loads like these fans, you should run an extra heavy-duty automotive relay. [Bosch] relay to switch another heavy duty automotive relay. Note that because a double-pole, double-throw (DPDT) relay has been used, another completely independent circuit can also be switched simultaneously. This other circuit can even turn off the second device as the first is switched on. Setting-Up There are two ways of setting the action of the Temperature Switch. First, if you have another means of monitoring the temperature (eg, via an engine-coolant temperature gauge or a temporary temperature probe and display), wait until the measured temperature reaches the desired trigger level, then turn set-point pot VR1 until the Temperature Switch just turns on. The turn-off value will be set by the hysteresis pot (VR2). If you want the turn-off value to be close to the Where To Buy A Kit This design was originally published in SILICON CHIP’s “Performance Electronics For Cars”. A kit of parts is available exclusively from Jaycar Electronics. “Performance Electronics For Cars” is available from Silicon Chip Publications and from Jaycar. 26  Silicon Chip turn-on temperature, set VR2 fully anti-clockwise. If you want the turn-off temperature to be much lower, adjust VR2 further clockwise. The other way of setting the trip point is to make some measurements on the bench. Table 1 shows typical NTC thermistor resistance values for a range of temperatures. The thermistor is 10kΩ at 25°C and falls to 34.5Ω at 245°C. Table 1 also shows the expected voltage across the thermistor at each temperature value, assuming the regulator output is at 8V. If the regulator voltage is slightly different to this, the value will need to be scaled accordingly. For example, if the regulator output is 7.8V, then the output voltage will be the value shown multiplied by 7.8V, all divided by 8V. You can measure the regulator’s output voltage by using a multimeter to probe the righthand terminal of the regulator with the PC board orientated as in the overlay and photos. Connect the other probe of the multimeter to ground. Make sure that you don’t slip with the multimeter probe and short-circuit the regulator! When VR1 is adjusted so that a particular voltage shown in Table 1 can be measured on its wiper terminal, the switch will trip at the corresponding temperature. For example, if you want the relay to close at 120°C, set VR1 so that its wiper voltage is 2.274V. The accuracy will be within about 2%. 1 PC board coded 05car101, 105 x 60mm 1 NTC thermistor, SOD27 leaded package, -40°C to 300°C (BC components 2322 633 83103) 5 PC-mount 2-way screw terminals with 5mm pin spacing 1 12V PC mount DPDT 5A relay (Relay1) 1 3-way header with 2.54mm spacing 1 jumper shunt with 2.54mm spacing 1 3m length of single core shielded cable 1 50mm length of 4mm diameter heatshrink tubing 1 1kΩ multi-turn top adjust trimpot (VR1) 1 1MΩ horizontal trimpot (VR2) Semiconductors 1 LM358 dual op amp (IC1) 1 7808 3-terminal regulator (REG1) 1 BC337 NPN transistor (Q1) 1 5mm red LED (LED1) 1 16V 1W zener diode (ZD1) 2 1N4004 1A diodes (D1,D2) 1 1N4148 diode (D3) Capacitors 2 100µF 16V PC electrolytic 2 10µF 16V PC electrolytic 1 100nF MKT polyester (code 104 or 100n) Resistors (0.25W, 1%) 1 22kΩ 2 1kΩ 4 10kΩ 1 10Ω 1 1.8kΩ Remember, if you wish the relay to close when the temperature goes above a particular value, install link LK1 in position “L/H” and install diode D3 as shown on the overlay. For the relay to close when the temperature goes below a certain value, install link LK1 in position “H/L” and install D3 the other way around. In most applications, once the Temperature Switch is set, it won’t need to be altered. The PC board fits into a 130 x 68 x 42mm jiffy box, so when the system is working correctly, it can be inserted into the box and tucked SC out of sight. siliconchip.com.au PC Oscilloscopes & Analyzers DSO Test Instrument Software for BitScope Mixed Signal Oscilloscopes DSO 2.0 4 Channel BitScope 2 Channel BitScope Digital Storage Oscilloscope  Up to 4 analog channels using industry standard probes or POD connected analog inputs. Mixed Signal Oscilloscope  Capture and display up to 4 analog and 8 logic channels with sophisticated cross-triggers. Spectrum Analyzer  Integrated real-time spectrum analyzer for each analog channel with concurrent waveform display. Logic Analyzer  8 logic, External Trigger and special purpose inputs to capture digital signals down to 25nS.  Record anything DSO can capture. Supports live data replay and display export. Data Recorder Pocket Analyzer BitScope DSO Software for Windows and Linux BitScope DSO is fast and intuitive multi-channel test and measurement software for your PC or notebook. Whether it's a digital scope, spectrum analyzer, mixed signal scope, logic analyzer, waveform generator or data recorder, BitScope DSO supports them all. Capture deep buffer one-shots or display waveforms live just like an analog scope. Comprehensive test instrument integration means you can view the same data in different ways simultaneously at the click of a button. DSO may even be used stand-alone to share data with colleagues, students or customers. Waveforms may be exported as portable image files or live captures replayed on other PCs as if a BitScope was locally connected. BitScope DSO supports all current BitScope models, auto-configures when it connects and can manage multiple BitScopes concurrently. No manual setup is normally required. Data export is available for use with third party software tools and BitScope's networked data acquisition capabilities are fully supported. Networking  Flexible network connectivity supporting multi-scope operation, remote monitoring and data acquisition. Data Export  Export data with DSO using portable CSV files or use libraries to build custom BitScope solutions. BitScope Designs Ph: (02) 9436 2955 Fax: (02) 9436 3764 www.bitscope.com Intelligent Car Air-Conditioner Controller This simple device stops the air-conditioner in your car from sapping engine power when going up hills or during overtaking, while still maintaining comfortable temperature levels inside the cabin. It’s based on a PIC microcontroller and is easy to build. By JOHN CLARKE 28  Silicon Chip siliconchip.com.au D URING THE HOT SUMMER months, your car’s air-conditioner works quite hard to keep cabin temperatures cool. As a result, fuel consumption increases due to the extra load imposed on the engine by the air-conditioning system or more specifically, by its compressor. But that’s not all – the extra load imposed on the engine by the compressor is readily noticed when travelling up hills, particularly in smaller 4-cylinder cars. In order to get around this problem, many drivers manually switch off the air-conditioner to ensure extra power during hill climbing or when overtaking. It’s almost like giving the car a mini “turbo boost”. On some new cars, this can even happen automatically. These cars have a “Wide Open Throttle” (WOT) cutout relay and this automatically switches off the air-conditioner’s compressor during high throttle conditions. If you wanted to maximise engine performance, you would only turn the air-conditioner on when going down hills or when slowing down. That way, the air-conditioner compressor could be used as a brake that converts the energy into cooling the cabin rather than being wasted as heat in the brakes or via engine braking. In practice, of course, it’s quite impractical for the driver to continually switch the air-conditioner on and off. In any case, the compressor would also have to run for at least some of the time on a relatively flat road in order to keep the cabin temperature to a comfortable level on very hot days. Doing it electronically But what if the switching could be done electronically? Well, that’s just what this clever little circuit does. Based on a microcontroller, it’s connected to various sensors in your car and automatically switches the air-conditioner off when the car is accelerating or going up hills. It then allows it to switch on again (if needed) when the car is slowing down or going down hills, or when the engine is only lightly loaded (eg, when travelling on the “flat”). So the concept is really quite simple. The circuit overrides the existing air-conditioner control system to turn the compressor off when the engine is heavily loaded. It then allows the airconditioner to operate normally when siliconchip.com.au Fig.1: the basic elements in a car air conditioning system. H ow A n A ir- C o n d it io n e r Wo r k s Fig.1 shows the basic elements of the air conditioning cycle. The system comprises condenser and evaporator coils, a compressor and an expansion valve. In operation, the compressor compresses the refrigerant gas. This causes the gas to become hot and it is then passed through the condenser (essentially a large radiator) to cool. In the process of giving up heat, the refrigerant becomes a liquid (ie, it condenses). This liquid is then passed through an expansion valve and this causes the liquid to expand into a low-pressure gas, significantly cooling it in the process. Following the expansion valve, the low-pressure refrigerant is passed through the evaporator coil. Any air that passes over this coil will be cooled, due to heat absorption by the cold evaporator. This cooling process also reduces the air’s capacity to hold moisture and so this condenses to form moisture on the evaporator coil. As a result, the air is also dehumidified. Lower air humidity allows the human body’s cooling system to work more efficiently by allowing water evaporation from the skin to occur more readily. Along with the lowered air temperature, this reduced humidity gives an additional cooling benefit. engine loads are light. In addition, the system can be set up to switch off the compressor when the vehicle is stationary (engine idling). That’s the basic concept but in practice there’s a lot more control “intelligence” built into the system as we shall see. In theory, this improved control should also reduce fuel consumption. However, we have not done any tests to confirm this. In order to understand how we can improve the operation of the airconditioner, let’s take a look at how we control it. If you are not sure how air-conditioning works, refer to the above panel entitled “How An Air Conditioner Works”. Temperature control Most older air-conditioners control the cabin temperature using a thermostat located in the cabin. This simply switches the compressor on or off, depending on the temperature. By contrast, modern climate control systems are much more complex in their operation. They generally use a thermistor to monitor temperature. Its output is fed to an electronic control January 2007  29 does not require a speed signal to be connected. (3) Low feature mode – used if you only want the controller to provide high-throttle compressor switch off. Alternatively, for this mode, you can ditch the Air-Conditioner Controller and use the Simple Voltage Switch from “Performance Electronics For Cars” instead – see panel. Inputs monitored Fig.2: how a car air-conditioner is wired into circuit. Note the alternative wiring arrangements for the condenser fan. circuit which then acts to direct air (via vents) over the evaporator, control the air-flow speed, maintain humidity levels and control the compressor. Our controller works with both types of air-conditioner systems. Override control One possible drawback to our controller is that the cabin temperature could rise uncomfortably high during extended hill climbs. As a result, we’ve included an optional override switch. By pressing this switch, the controller is disabled for a preset period, so that the air-conditioner operates normally. This preset period can be set anywhere from 2-10 minutes, with each switch press giving a 2-minute increment. In addition, the unit can (optionally) be set so that the compressor comes on for longer that it normally would during deceleration. In other words, the cabin is cooled down further than normal. The idea here is that the compressor then won’t have to come on as much as usual on level stretches of road. Of course, this extended cool-down period also causes wider than normal temperature fluctuations in the cabin temperature, although this can be adjusted to suit individual preferences. Alternatively, you can dispense with this feature altogether, depending on the settings chosen during the set-up procedure. Three operating modes The firmware allows the user to select one of three different operating modes when setting up the Air-Conditioner Controller. These are: (1) Full mode – this includes the highthrottle compressor switch off, the low-throttle extended cool-down period (compressor on) and compressor switch-off when the engine is idling. (2) Medium mode – this is the same as the full mode but does not include compressor switch-off when the vehicle is stationary. This mode Main Features • • • • • • • Automatically switches compressor off when car is accelerating or travelling up hills (high throttle) Compressor may run with low throttle even when the cabin temperature setting has been reached Automatically switches compressor off when car is stationary Standard compressor operation with normal throttle position Override switch Optional speed signal input LED indicators for main functions 30  Silicon Chip In operation, the Air Conditioner Controller monitors the car’s throttle position sensor in order to gauge engine load. In addition, there’s a speed signal input, a compressor “flag” input and the above-mentioned override switch input. The speed signal input applies mainly to city driving conditions, where vehicles invariably spend a lot of time sitting at traffic lights. This input (derived from the speedometer signal) allows the Air Conditioner Controller to automatically switch off the compressor when the vehicle is stationary. Alternatively, if most of your driving is in the country, you may not wish to use this feature since the engine won’t spend much time idling. In that case, it’s simply a matter of leaving the speed input disconnected. Compressor flag input The compressor flag signal is normally used to directly drive the compressor. It goes high (+12V) to turn the compressor on when the cabin requires cooling and low (0V) when the temperature setting is reached. In this application, however, the compressor flag is used as an input. Its job is to indicate to the controller whether the compressor would normally be on or off. Basically, the Air Conditioner Controller intercepts the compressor signal and processes this along with the other inputs. It then switches the compressor on and off via an external relay. Fig.2 shows how the compressor is normally wired, while Fig.3 shows the wiring with the Air Conditioner Controller installed. Logging the flag signal In operation, the on/off duty cycle of the flag signal is logged by the controller. This is done so that the controller can determine the necessary extra compressor turn-on period during desiliconchip.com.au Fig.3: this diagram shows how the wiring is rearranged to include the Air-Conditioner Controller. The compressor and its condenser fan are now switched on and off by the controller via an external relay (Relay1). The second relay (Relay2) is used only if the vehicle uses the alternative condenser fan wiring. celeration and braking. The flag signal isn’t logged continuously though, as this would give an erroneous indication of the overall duty cycle. Let’s take a closer look at this. First, the flag signal isn’t logged if it goes high during high engine load conditions. That’s because the controller will have disabled the compressor and this in turn can cause the flag signal to go high (in a vain attempt to turn the compressor on) for much longer periods than normal. As a result, the duty cycle would quite unrealistic if it was to be measured. Conversely, we do log the flag signal when it is low during high engine load conditions, since it is no longer affected by the actions of the controller. That’s not the end of it. Again, for low-throttle positions, the flag signal is not logged if it is low and the compressor is running, as the controller is again effectively overriding the flag signal. Similarly, there’s no logging when the engine is idling and the compressor flag is high, because the controller prevents the compressor from running. Basically, logging only takes place when the controller is not overriding the flag signal and the air-conditioner is operating “normally”. If there is intervention one way or other by the controller, the logging ceases. siliconchip.com.au Any logging that does take place only begins after the compressor flag signal goes low and then high again, indicating the start of normal thermostatic control by the air-conditioning system. Any logging before then (ie, immediately after the air-conditioner has been turned on) would again give a false result. In operation, the compressor flag signal is actively logged over a period that can be set from 1-16 minutes. This logging time excludes those periods when logging is paused. The extended cool-down function only becomes fully operational when there is a satisfactory log of the flag signal for processing by the PIC microcontroller. The default length of the extended cool-down period is set by the multiplier adjustment. Other settings Apart from the multiplier adjustment, there are three other main settings: the adaptation setting, the logging period and the retrigger period. The adaptation setting modifies the length of the cool-down period according to the driving pattern. At its minimum setting, the extended cooldown period is the same each time it is activated. By contrast, at higher settings, the extended cool-down period is progressively reduced according to the number of times the vehicle slows down (or decelerates) in a given time period. The idea here is that we can afford to reduce the length of the extended cool-down periods if they are occurring quite frequently. The logging period can be set anywhere between 64 seconds to 16 minutes in 64s steps. However, the total number of samples in the whole logging period is always 128. Generally a 4-5 minute logging period will be suitable (ie, the compressor flag will be sampled approximately every 2.5s). However, if the compressor normally switches on and off at a fast rate, it may be necessary to use a shorter logging period to correctly sample the compressor flag signal. Finally, the retrigger setting sets the minimum delay between switching the compressor off and then on again (and vice versa). It only comes into effect during high-throttle switching (compressor off), low-throttle cooldown switching (compressor on) and idle switching (compressor off). Basically, the retrigger period functions as a timer to prevent the compressor from being switched on and off at a rapid rate. It can be set anywhere from 0-15s, although a 2-3s setting will generally be suitable. The retrigger setting does not affect January 2007  31 Specifications • • • • • • • • • • • • Compressor monitor period: adjustable in 64-second steps from 64s to 16 minutes. Compressor sampling period: selected with monitor period from 0.5 to 7.5s Multiplier effect: adjustable in 0.8% steps from x1 to x2 Adaptation adjustment: from standard to full in 16 steps. Throttle input range: 0-5V with R1 out; 0-14.8V with R1 in. Low throttle adjustment: 0-5V or 0-14.8V. High throttle adjustment: 0-5V or 0-14.8V. Compressor retrigger period: adjustable in 1s steps from 0-15s (with 0.5s uncertainty). Compressor flag input: 0-15V. Speed signal input sensitivity: 1.2V (VR4 fully clockwise) to 3V (VR4 at two thirds anticlockwise). Override period: adjustable from 2-10 minutes with 2-minute increments per switch press. Current consumption: 200mA with all LEDs lit and compressor relay on. the time taken to switch the compressor off under high throttle settings. It is also disabled when the compressor is behaving normally in response to the flag signal, since it will be operating within the manufacturer’s specifications. Condenser fan drive As shown in Fig.2, car air-conditioning systems run an electrically operated condenser fan to help transfer heat from the condenser to the ambient air. This fan can be wired so that it either runs only when the compressor is on or so that it runs permanently whenever the air-conditioner is turned on, regardless as to whether the compressor is running or not. Our controller caters for both types of fan wiring. In the first case, the condenser fan is left connected across the compressor and both are controlled via the same output from the controller. In the second case, the fan is driven via a separate controller output (and external relay). This is done because the controller may run the compressor once more after the air-conditioner has been switched off to implement the extended cool-down function. Circuit details Its operation may sound complicated (thanks to the software options) but the circuit itself is really very simple. Fig.4 shows the details. 32  Silicon Chip PIC microcontroller (IC1) is the heart of the circuit. This accepts the various inputs, runs the software program to perform the various functions and drives the relays and several LED indicators. The software is quite involved, with about 1500 lines of code. Much of the programmed code provides the decision logic for the extended cool-down feature. In its basic form, IC1 is programmed to monitor inputs from the speed-o­ meter signal, the throttle position sensor and the compressor flag signal. It processes these inputs and drives the compressor (via Relay1) according to the software logic. In addition, there are inputs from trimpots VR1-VR3 and override switch (S1), with further options provided by links LK1 & LK2 – see Tables 3 & 4. The main outputs from IC1 appear at RA0 and RA1 (pins 17 & 18) and these drive NPN transistors Q2 and Q3, along with indicator LED6 (Compressor On). Additional outputs at RB5, RB7, RA6 & RA7 drive LEDs 2-5 respectively. As shown, the speedometer signal is fed to the base of transistor Q1 via a voltage divider consisting of 10kW and 1kW series-connected resistors and trimpot VR4. Zener diode ZD2 clamps any voltages above 16V, while the associated 10nF capacitor shunts unwanted high-frequency signals. Trimpot VR4 functions as a sensitivity control for the speed sensor signal. When VR4 is set to maximum (10kW), Q1 switches on when the speed sensor signal goes above 1.2V and off when the signal goes below this threshold. Setting VR4 to a lower resistance value attenuates the signal fed to Q1’s base, which means that the speed signal (and thus the vehicle’s speed) must be higher for Q1 to turn on. Q1’s collector is normally held high (at +5V) via a 10kW resistor. When Q1 turns on, the collector voltage is pulled low to about 200mV. A 1nF capacitor provides further high-frequency filtering before the signal is applied to the RB1 input (pin 7) of IC1. The override switch S1 connects to the RB0 input (pin 6) of IC1 via a 1kW resistor. This resistor and its associated 100nF capacitor provides RF filtering, to keep unwanted noise out of the RB0 input. The RB0 input is normally held high via an internal pull-up resistor. However, when S1 is closed, RB0 is pulled low (towards 0V) and this is detected by the software. As a refinement, the software includes a routine that makes sure that very short switch closures or transients are ignored. Throttle position The throttle position is monitored at the AN5 (pin 12) input via a 1MW resistor. This resistor has a high value in order to prevent any loading on the car’s throttle position sensor. ZD3 clamps any transients that exceed 16V, while the 100nF capacitor filters the signal to remove high-frequency noise. Resistor R1 (510kW) is included to attenuate the throttle position sensor output if its voltage range goes up to 14.4V. Alternatively, this resistor is left out for speed sensors with a 0-5V range (the more usual case). IC1 converts the voltage applied to its AN5 input to a digital value. In this case, 0V is converted to “0”, while 5V becomes 255. Voltages between these extremes have values between 0 and 255. Next in line is the compressor flag input and this connects to RB4 (pin 10) via series 100W and 10kW resistors. Zener diode ZD4 and the 100nF capacitor again act to clamp transients and filter the input signal. A high-level compressor flag signal (up to 14.4V) is indicated via LED1 which is connected siliconchip.com.au Fig.4: the circuit is based on PIC microcontroller IC1. This device monitors several input signals and controls the compressor and its condenser fan via external relays. via a 3.9kW current-limiting resistor. Inputs RB2 & RB3 are for links LK1 & LK2. These inputs are normally held high (+5V) via internal pull-up resistors. When a link is installed, its corresponding input is pulled low to 0V. Link LK1 selects the function of trimpots VR1, VR2 & VR3, while LK2 is installed if you want to dispense with the “compressor off when vehicle is stationary” feature in Medium mode (see Table 3). Trimpots VR1, VR2 & VR3 each connect across the 5V supply, with their wipers connected to the AN2, AN3 & AN4 inputs respectively. The voltages on their wipers are converted to digital siliconchip.com.au values in a similar manner to the voltage on the AN5 input. These values then set the multiplier value and the low and high-throttle thresholds when link LK1 is out (Table 4). Alternatively, they set the adaptation value, the logging period and retrigger period when LK1 is installed. Indicator LEDs Indicator LEDs LED2-LED5 are driven by the RB5, RB7, RA6 and RA7 outputs of IC1. These show the speed signal, high throttle, low throttle and override conditions, respectively. In operation, the Speed LED (LED2) flashes at a 1Hz rate when a speed sig- nal is detected. By contrast, the HighThrottle LED (LED3) lights continuously when the throttle position sensor voltage goes above a threshold set by VR3. Conversely, the Low-Throttle LED (LED4) lights when the throttle sensor voltage goes below a threshold set by VR2. LED 5 is the Override indicator. It lights for the duration of the override period when switch S1 is pressed. Finally, LED6 indicates when the compressor is on, which is whenever IC1’s RA0 output goes high. This output also drives the base of transistor Q2 via a 1kW resistor. When RA0 goes high, Q2 turns on and drives Relay1. January 2007  33 Fig.5: install the parts on the PC board as shown here. Resistor R1 is installed only if the throttle sensor output exceeds 6V (see text), This is the fully-assembled PC board. Note how the indicator LEDs are mounted. Transistor Q3 is driven by output RA1 in a similar manner to Q2. This transistor drives Relay2 which in turn controls the condenser fan in some installations. Power supply Power for the circuit is derived from the vehicle’s ignition supply. This is fed to 3-terminal regulator REG1 via diode D1 which provides reverse polarity protection. A 10W resistor and 470mF capacitor decouple the supply following D1, while zener diode ZD1 (16V) protects REG1 from damage due to voltage transients. Pin 4 (MCLR) of IC1 is connected 34  Silicon Chip the REG1’s output via a 1kW resistor. This pin resets the microcontroller each time power is applied. Construction All parts (except the relays) are installed on a PC board coded 05101071 (107 x 61mm) and this is housed in a plastic box measuring 130 x 68 x 44mm. PC-mount screw terminals at either end of the board take care of the external wiring connections. Fig.5 shows the assembly details. As usual, start by carefully checking the PC board for defects (shorted tracks or breaks in the copper pattern, etc). While you’re at it, check the hole sizes. In particular, check the holes for the screw terminals and the four cornermounting holes. Enlarge these holes if necessary. That done, install all the resistors but note that R1 should be left out for the time being. Table 1 shows the resistor colour codes but you should also use a digital multimeter to check the values as some colours can be difficult to decipher. The diodes and IC socket can go in next, taking care to ensure that they are all oriented correctly. Follow these with the capacitors, again taking care to ensure that the electrolytics go in the right way around. Transistors Q1-Q3 are next on the list, after which you can install LEDs16. The latter should be mounted so that the top of each LED is 28mm above the PC board (pushing the LEDs down onto a cardboard spacer between their leads is the best way to achieve this). Make sure that each LED goes in with its anode lead towards the left (the anode lead is the longer of the two). Note that LEDs 1&6 are red while the remaining four LEDs are green. The 3-terminal regulator REG1 is next on the list. As shown, this device is mount­ed with its metal tab flat against the PC board. It’s installed by first bending its leads down by 90°, then slipping it into position and fastening its tab to the board using an M3 x 6mm screw and nut. That done, its leads are soldered to the PC board and cut to length. siliconchip.com.au Don’t solder REG1’s leads before bolting down its metal tab to the board. If you do, this could impose strain on the soldered joints and crack the board tracks. The board assembly can now be completed by installing trimpots VR1VR4, the screw terminal blocks and the link headers for LK1 & LK2. Don’t install IC1 in its socket yet, though – we’ll get to that shortly. Testing The test procedure is quite brief and simply consists of checking the supply rails before IC1 is plugged into its socket. To do this, apply power to the +12V and 0V terminals and check that there is 5V between pins 14 & 5 of IC1’s socket. If this is correct, switch off and install IC1, taking care to ensure it is oriented correctly – see Fig.5. Adjustments Initially, before switching on the Air Step 4: if you have an oscillator connected, set it at about 100Hz (or anywhere between 2Hz and 1kHz) and adjust trimpot VR4 (sensitivity) so that the speed LED flashes. If the LED does not flash, check that the oscillator level is sufficient. When the oscillator is disconnected the LED should stop flashing. Step 5: rotate the external potentiometer fully anticlockwise and check that the Low-Throttle LED lights. Conversely, check that the High-Throttle LED lights when the potentiometer is rotated fully clockwise. Step 6: set the potentiometer mid-way so that neither throttle LED is lit. Now press the compressor flag switch. The compressor flag LED (LED1) should immediately light, followed by the compressor LED (LED6) within 0.5s. Release the switch and both LEDs should extinguish. Step 7: press and hold the compressor flag switch again and check that the compressor LED extinguishes as the pot is rotated clockwise to a high setting. Step 8: check that the signal generator is off and press and hold the compressor flag switch. Check that the compressor LED goes off as the potentiometer is rotated fully anticlockwise. If the signal generator is now connected, then the compressor LED should come on. Note that if link LK2 is installed, the compressor LED should stay lit for low potentiometer settings even when there is no oscillator signal. Step 9: set the potentiometer mid-way Conditioner Controller for the very first time, the programmed settings are: Multiplier – x1.2; Low Throttle Threshold – 1.25V; High Throttle Threshold – 3.75V; Adaptation – minimum; Logging Period – 5 minutes; Retrigger Period 5s. However, these settings will be immediately altered by the settings of VR1, VR2 & VR3 when power is applied. As indicated previously, LK1 also plays a role here. If LK1 is out, then the Multiplier, Low Throttle and High Throttle settings will be set by VR1-VR3. Conversely, if LK1 is in place, then the Adaptation, Logging Period and Retrigger Period will be adjusted by the trimpots – see Table 4. Once a setting is changed, it is remembered unless changed again via the link and trimpot adjustments. You will need to make a note of the settings for VR1, VR2 and VR3 so you can return these to their selected settings whenever the link is changed to make the alternative adjustments. The initial tests can be performed using the test setup shown in Fig.6. You will need a couple of momentarycontact pushbutton switches, a 10kW (or any value up to 100kW) linear potentiometer (to simulate a throttle position sensor) and some hook-up wire. If you have one, a signal generator (or oscillator) can be used to check the speed signal detection. It’s then just a matter of following the procedure set out below. Step 1: install LK1 and adjust VR1, VR2 and VR3 fully anticlockwise. This will set the Logging Period to 64s, the Retrigger Period to 0s and the Adaptation to its minimum setting. Step 2: remove LK1 and adjust VR1 fully clockwise to set the multiplier to x2. Step 3: set VR2 about 1/4 of a turn clockwise and VR3 about 3/4 of a turn clockwise. Table 2: Capacitor Codes Value 100nF 10nF 1nF mF Code IEC Code EIA Code 0.1mF 100n 104 .01mF   10n 103 .001mF   1nF 102 Table 1: Resistor Colour Codes o o o o o o o o siliconchip.com.au No. 1 1 3 1 10 1 1 Value 1MW 510kW 10kW 3.9kW 1kW 100W 10W 4-Band Code (1%) brown black green brown green brown yellow brown brown black orange brown orange white red brown brown black red brown brown black brown brown brown black black brown 5-Band Code (1%) brown black black yellow brown green brown black orange brown brown black black red brown orange white black brown brown brown black black brown brown brown black black black brown brown black black gold brown January 2007  35 Fig.6: this is the test set-up for the controller board. The 10kW potentiometer simulates the throttle sensor, while an external oscillator is used to simulate the speedometer signal input. and press the compressor flag switch for about 16s. At the end of 16s, release it for 16s, then press it again for another 16s and release it for 16s. This will build up an on-off duty cycle log of the compressor flag signal over the 64s logging period. Step 10: release the compressor flag switch during low throttle (ie, low throttle LED lit). Check that the compressor flag LED extinguishes, while the compressor drive LED stays lit for a short period before it too switches Table 3: Modes Mode Link LK2 Speed Signal High Out Required Medium In Not Required Low Out Not Required off. This is the cool down period and will not be initiated again until the compressor drive flag goes from low to high again (ie, by releasing and then pressing the compressor flag switch). Step 11: press the override switch (S1) and check that the override LED lights. The compressor output LED should now light whenever the compressor flag LED lights (ie, when S2 is pressed). This should happen for any potentiometer setting and regardless as to whether the oscillator (speed) signal is on off. This override should continue for two minutes. Assuming that everything checks out, the finished PC board can be installed in a UB3 box by clipping it into the integral side pillars. The indicator LEDs protrude through matching holes in the lid and these can be drilled using the front-panel artwork Table 4: Setting The Trimpots Link LK1 Out In VR1 VR2 VR3 VR4 Multiplier Low throttle High throttle (anticlockwise x threshold (anticlockwise 1, clockwise x 2 (anticlockwise 0V, clockwise 5V in 0.8% steps) 0V, clockwise 5V at pin 12 in 255 at pin 12 in 255 steps) steps) Speed signal sensitivity (Anticlockwise low sensitivity, clockwise maximum sensitivity) Adaptation (anticlockwise no adaptation, clockwise maximum in 16 steps) Speed signal sensitivity (anticlockwise low sensitivity, clockwise maximum sensitivity) 36  Silicon Chip Logging period (anticlockwise 64 seconds, clockwise 16 minutes in 64 second steps) Retrigger period (anticlockwise 0 seconds, clockwise 15 seconds in 1 second steps) as a template – see Fig.7. You will also have to drill holes at either end of the box to pass the external wiring to the terminal blocks. Installation Fig.3 shows the installation details. First, you will need to trace some of the connections in your car’s wiring. The speedometer signal wire will need to be located, as will the throttle position sensor and compressor drive wiring. That means that a copy of your car’s wiring diagram is an absolute necessity. In addition, you will need to locate a +12V ignition terminal (ie, a wiring point that only goes to +12V when the ignition is on). This can easily be located inside the fuse box. If you don’t intend to use the speed signal input in Medium Mode (ie, you don’t want the compressor to automatically cut out when the vehicle stops), install link LK2 on the PC board – see Table 3. Once you’ve located the throttle position sensor lead, use a multimeter to determine its output voltage range. Normally it covers the range from just above 0V at idle throttle position through to about 5V at full throttle. It’s just a matter of turning the ignition on (but not starting the engine) and then adjusting the accelerator position while you make the voltage measurements. If the voltage is above about 6V with high throttle, install resistor R1 on the PC board. If it is around 6V or less, the resistor can be left out. siliconchip.com.au What If The Compressor Runs All The Time? Parts List Some car air conditioners are not thermostatically controlled, which means that the compressor runs continuously while ever the air-conditioner is switched on. In this case, there’s not much point in logging the compressor flag signal since it will be high all the time. As a result, you will not be able to use the controller’s extended cool-down feature. The controller can still be used to automatically switch off the compressor when the vehicle is accelerating (high throttle) and when the vehicle is stopped, however. Alternatively, you might want to consider using the SILICON CHIP Voltage Switch to simply switch off the compressor under high-throttle conditions. This circuit was published in “Performance Electronics for Cars” and is simpler (and cheaper) than the controller featured here. Note, however, that the on-board relay used in the Simple Voltage Switch will NOT be suitable for switching the compressor on and off. Substitute a 30A horn relay as specified in this article. Finally, be sure to set the hysteresis wide enough to prevent the compressor from rapidly switching on and off. 1 PC board, code 05101071, 107 x 61mm 1 UB3 box, 130 x 68 x 44mm 1 SPST momentary panel switch 2 30A SPST horn relays (Relay2 optional; see text) (Jaycar SY4068 or equivalent) 2 30A horn relay bases (one optional; see text) (Jaycar SY4069 or equivalent) 1 3-way PC-mount screw terminal block, 5.08mm spacing 4 2-way PC-mount screw terminal blocks, 5.08mm spacing 4 10kΩ horizontal mount trimpots (VR1-VR4) (code 103) 1 18-pin DIL IC socket 1 M3 x 6mm screw 1 M3 nut In addition, the wiring to the condenser fan needs to be checked out. Fig.2 shows the two possible wiring configurations, while Fig.3 shows how each configuration is connected to the controller. Note that the 85, 86, 30 & 87 numbers in Fig.3 refer to the connections marked on the relay for the coil and the relay contacts. Note also the Relay2 is not required if the condenser fan is connected directly across the compressor and its series pressure switch. Be sure to use 30A automotive horn relays, as specified in the parts list. These can be bolted to the chassis and plugged into the specified bases. The wires from the relay bases are then lengthened and spliced into the car’s wiring using insulated automotive crimp connectors. Similarly, use automotive connectors to make the connections to the sensors, the +12V and 0V (chassis) supply connections and to the override switch. If you have an older car, the latter can be installed on the dashboard. On more modern cars, it can be hidden under the dash but should still be readily accessible. Note that the ignition-switched +12V supply to the controller should not go to 0V when the starter motor is cranked. Pressure switch What ever you do, make sure that the pressure switch is included in series with the compressor – see Fig.2 & Fig.3. It’s there to independently siliconchip.com.au 24V Operation Want to operate this unit from a 24V supply? It’s just a matter of changing a few component values, as follows: ZD1-ZD4 should be 33V 1W zener diodes; the 470mF capacitor at the input to REG1 should be rated at 35V; the 100mF capacitor decoupling the relay supply should be rated at 35V; if R1 is needed it should be 220kW; and finally, the relays must have 24V coils. switch off the compressor to prevent icing when necessary. Note also that you will need to initially wire the Air Conditioner Controller so that it can be accessed for easy adjustment. After you are satisfied with the adjustments, it can later be tucked up out of the way under the dashboard. Adjustments Once the installation is complete, you need to go through the following steps: Step 1: Switch on the ignition so that power is applied to the Air Conditioner Controller. Step 2: Press the accelerator down very slightly and adjust VR2 (with LK1 out) so that the Low-Throttle LED just lights. Step 3: Press the accelerator down to the position you normally use for brisk acceleration (or for going up hills) and Semiconductors 1 PIC16F88 microcontroller programmed with aircon.hex (IC1) 3 BC337 NPN transistors (Q1-Q3) 1 7805 5V regulator (REG1) 3 1N4004 1A diodes (D1-D3) 3 16V 1W zener diodes (ZD1-ZD3) 2 3mm red high-intensity LEDs (LED1,LED6) 4 3mm green high-intensity LEDs (LED2-LED5) Capacitors 1 470mF 16V PC electrolytic 2 100mF 16V PC electrolytic 1 10mF 16V PC electrolytic 4 100nF MKT polyester 1 10nF MKT polyester 1 1nF MKT polyester Resistors (0.25W, 1%) 1 1MΩ 10 1kΩ 1 510kΩ (R1) 1 100Ω 3 10kΩ 1 10Ω 1 3.9kΩ Miscellaneous Automotive wire, connectors. adjust VR3 so the High-Throttle LED just lights. Step 4: Install LK1 and adjust the adaptation control (VR1) to fully anticlockwise, the logging period (VR2) to 5 minutes (about 1/3 of a turn clockwise) and the retrigger (VR3) to mid-way for about 7.5s. For a longer retrigger period, set VR3 fully clockwise. If you are not concerned about the compresJanuary 2007  37 This Unit Doesn’t Suit All Cars Warning! This Air Conditioner Controller is designed to work with cars that have a throttle position sensor that delivers a voltage dependent on throttle position. This type of sensor is normally installed in cars that use electronic fuel injection and engine management. Cars with a carburettor fuel system are unlikely to include a throttle position sensor. Cars with a carburettor could, however, be modified to include a potentiometer that is operated by the throttle. A long life potentiometer would be required, such as one available from Farnell Cat. 469-9518 (www.farnellinone.com. au). This is a Vishay 10kW linear conductive plastic potentiometer rated for five million operations and 125°C. A 5V supply for the high throttle end of the potentiometer could be obtained from the 5V output of REG1. The 0V signal could be obtained from the 0V input or the chassis. The potentiometer’s wiper provides the throttle position voltage. Note that a low voltage output should coincide with a low throttle, while a high voltage output should be produced at high throttle positions. The speed signal must be derived from a signal pulse train that’s fed out of the engine management computer (ECU); eg, the speedometer signal – see warning panel. Alternatively, if the ECU doesn’t have a speed signal input, a signal can be derived directly from the speedometer sensor. A cable-operated speedometer is usually not suitable unless the speedometer outputs a signal for the engine management computer. A speed signal could also be derived from the drive shaft using a magnet and coil in a similar manner to that used in the Speed Alarm published in SILICON CHIP in November and December 1999. Be sure to derive the speed signal for this unit from your car’s speedometer signal – ie, from an output from the engine management computer (ECU). DO NOT tap into a speed sensor signal that’s used as an input to the ECU. The reason for this is that many cars now have anti-lock braking (ABS), traction control, electronic stability control and other systems that rely on speed sensor signals to the ECU. Tapping into one of these signals could upset the operation of these important systems. sor rapidly switching on and off, then set VR3 fully anticlockwise. Test drive It’s now time for a test drive, to see how the controller performs. Here’s the procedure: Step 1: Start the car and turn the airconditioner on, then lift the bonnet and check that the condenser fan runs correctly with its new wiring. Step 2: Drive the car. When the com- pressor flag LED goes out, the cabin will have cooled to the thermostat setting. When it does, press the override switch to allow the compressor flag signal to be logged without the controller’s high load and low throttle settings affecting the compressor drive. Note: the override switch is not normally used to allow the logging of the compressor flag signal. It’s simply used during this initial adjustment procedure to make setting-up much Fig.7: this full-size artwork can be used as a drilling template for the front panel. 38  Silicon Chip faster and more predictable. Step 3: During the override period, watch the compressor action. There may be long periods that the compressor is on and long periods where it is off. You need to set the logging period so that it’s long enough to cover at least several compressor flag on and off cycles. This is done using VR2 with LK1 installed – see Table 4. Step 4: Observe the Low and HighThrottle LEDs. You may need to readjust the settings here to suit your driving style. For example, the high throttle LED may not light at the required acceleration rate. Alternatively, it may light when simply cruising, in which case VR3 should be adjusted further clockwise (LK1 out). If the low throttle LED lights under cruise conditions, turn VR2 further anticlockwise to correct this. Step 5: If you needed to alter the logging period in step 3, press the override switch again. When the override period expires, check the cool down operation on low throttle. Adjust VR1 for the required multiplier effect (LK1 out). Note: setting VR1 fully anticlockwise disables the cool down feature, while fully clockwise gives a long cool down period. Step 6: Set the adaptation level for personal preference using VR1 (LK1 in). And that’s it, although you may need to do some further fine-tuning later on based on further driving experience. In the meantime, you can enjoy the performance benefits of your new “intelligent” air-conditioner. SC siliconchip.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. DRM down-converter for 455kHz IF receivers This project came about due to my interest in a new form of radio transmission called DRM, which stands for “Digital Radio Mondiale” (see www.drm.org). This is a new form of digital shortwave transmission. A few devices are available from Europe for decoding the digital signals but are expensive. I decided instead to modify an existing circuit, using a stable purpose-built 470kHz ceramic resonator as the oscillator, rather than the original unstable L/C version. The 455kHz IF signal from a shortwave receiver is fed into the input (pin 1) of a double-balanced mixer and oscillator (IC1) via a level adjustment pot (VR1). The NE506’s output (pin 4) is then AC-coupled to a PC’s sound card input for processing. With the capacitor between pins 5 & 7 set to 150pF, the oscillator frequency should be around 467.5kHz. You can check if the oscillator is working by putting it near a receiver tuned to 467kHz. You should hear a beat frequency. The IF signal of 455kHz is mixed with 467kHz, giving an output with a centre frequency of 12kHz. Sound cards should have no trouble sampling the 10kHz-wide DRM signal. A number of software-defined radio applications were found to work well with this converter. These applications perform all of the demodulation (SSB, AM, FM, etc) and various other DSP functions. If all is well, connect your 455kHz IF to the input and your computer sound card to the output. Run the Dream software (see http:// drm.sourceforge.net), and tune to 6095Khz (RNZI), or 1440Khz (SBS). You should see the Dream software lock onto the DRM transmission and audio should start playing from the computer speakers. The NE602AN mixer/oscillator and 470kHz resonator are available for a cost of $12.50 - email the author for more details at jwtitmus<at> bigpond.com. A CD with various software defined receivers as well as the latest Dream software decoder is also available. John Titmuss, VK4JWT. ($40) Contribute And Choose Your Prize As you can see, we pay good money for each of the “Circuit Notebook” items published in SILICON CHIP. But now there are four more reasons to send in your circuit idea. Each month, the best contribution published will entitle the author to choose the prize: an LCR40 LCR meter, a DCA55 Semiconductor Component Analyser, an ESR60 Equivalent Series Resistance Analyser or an siliconchip.com.au SCR100 Thyristor & Triac Analyser, with the compliments of Peak Electronic Design Ltd www.peakelec.co.uk So now you have even more reasons to send that brilliant circuit in. Send it to SILICON CHIP and you could be a winner. You can either email your idea to silicon<at>siliconchip.com.au or post it to PO Box 139, Collaroy, NSW 2097. January 2007  39 Circuit Notebook – Continued Mechanical soldering iron timer A timer mechanism salvaged from a defunct clothes dryer makes an ideal soldering iron timer. With a maximum run time of two hours, it uses no power in standby, has no microcontroller or menu system and doesn’t need batteries! To boot, it makes a loud audible click when it switches off, at which time if you are still using the iron a quick twist of the knob keeps the iron hot! No modifications are needed to the timer and it fits neatly into a typical redundant plugpack housing after the original transformer has been discarded. Use a 3-pin (not 2-pin) plugpack housing so that the mains earth connection can be retained. The only additional components needed are a 240V mains outlet socket, which is fitted to the bottom of the plugpack housing, and a neon indicator. The original knob can be reused or a fancier unit (which must be insulated; ie, plastic) can be sourced from the usual electronics outlets. You can even make up a professional looking label like that shown in the photos with a bit of work in your favourite graphics program! Cable for the internal wiring job can be scavenged from a section of 7A or 10A mains flex. The Neutral and Earth pins in the plugpack housing are wired directly to the mains outlet socket, whereas the Active pin goes to the common terminal on the timer. Another connection is then made from a switched terminal on the timer to the Active terminal on the mains outlet socket. Usually, there are two sets of switch­ ed terminals on the timer mechanism; one set go to the fan motor, while the other set go to the heater. The fan motor contacts close as soon as the timer is activated, whereas the heater contacts don’t close until the timer is set to more than 10 minutes or so. This provides the usual cool-down period at the end of a drying cycle. Use the fan motor contacts for this application. This photo shows the author’s finished prototype and the mechanical timer. Be sure to use a 3-pin plugpack case, to provide for mains earthing at the outlet socket. Note that if you’re reusing a typical 90V neon scavenged from old equipment, then you’ll need to add a 220kW dropping resistor in series. Off-the-shelf 240VAC neon indicators have this resistor built in. The neon is wired across the switched Active and Neutral lines. Finally, don’t attempt to build this device unless you are experienced at working with mains voltages and understand exactly what you are doing. Ron Russo, Kirwan, Qld. ($40) Toslink splitter Here’s a simple circuit that allows the single Toslink (digital optical) output present on recent appliances such as DVD recorders to be split into two identical outputs. It uses a Toslink receiver and two Toslink transmitter units from Jaycar Electronics, Cat. ZL3002 and ZL-3000, respectively. The Toslink units require a regulated 3V supply, which in this case is provided by a programmable 3-terminal regulator (REG1). This allows the circuit to be powered from an unregulated 6-12V DC plugpack. 40  Silicon Chip If a regulated supply is available, the circuit could be simplified by replacing the series regulator with a simple shunt regulator comprised of a 3.3V zener diode, a limiting resistor and a 10uF filter capacitor. The prototype was constructed on a small piece of stripboard. If required, it should be possible to add more transmitter units in parallel, up to the limit of the drive capabilities of the receiver’s digital output. Mike Abrams, Capalaba, Qld. ($40) siliconchip.com.au Telephone intercom offers privacy Recently a local Amateur Dramatic Society requested an intercom to operate between back-stage and the lights and sound control booth. For this application, voice levels must be inaudible to the audience, while at other times loud enough to be heard above the house music. The usual over-the-counter intercoms proved unsuitable, as they all seem to employ an open system with no privacy. In contrast, the accompanying circuit offers normal phone conversation between two points and even whispered communication when necessary. As you can see, the circuit is based around a simple interconnection between two standard tele­ phones via a standard telephone cable. This idea was lifted from a Circuit Notebook item published several years ago. The embellishments consist of a silent signalling circuit, plus an optional low-level auditory call function. When power is applied, a 555 timer (IC1) operates continually, providing a low-frequency square wave to the base of Q1, while the remainder of the circuit is passive. On lifting either handset, that station draws current and excites the associated relay (RLY1 or RLY2). For example, if the operator at Station B presses S2 to call Station A, RLY2 closes, flashing the LEDs in both the local and remote stations. This condition is maintained until Station A picks up. Now RLY1 closes as well, pulling the 555’s reset input (pin 4) low via RLY1a & RLY1b’s contacts. Thus the LEDs stop flashing but remain illuminated. Pressing either switch S1 or S2 results in the opposite buzzer sounding, regardless as to whether either handset is lifted. The circuit is symmetrical, so the reverse situation (A calls B) is obvious. Zener diode ZD1 reduces the voltage across the 555 to less than 18V, needed here because the unregulated DC supply puts out around 26V unloaded. Brian Critchley, Elanora Heights, NSW. siliconchip.com.au Brian C ri is this m tchley on winner th’s Peak At of a las Instrum Test ent January 2007  41 Circuit Notebook – Continued Versatile multi-driver speaker connections Many speaker enclosures used for public address systems or musical instruments contain pairs of identical speakers. Sometimes it is useful to be able to choose if these speakers are to be operated in series or parallel, or even to be able to drive the enclosure from a stereo source. Such flexibility is particularly useful when a number of different speakers and amplifiers are used together in various combinations. For example, an enclosure containing two 50W 8W drivers could be operated with the speakers connected in parallel when driven by a 100W 4W-capable amplifier or in series when driven by a 200W 8Wcapable amplifier. In latter case, the amplifier sees only 16W and so can drive a further 100W 16W load. When wired as shown, Cliffstyle switching 6.5mm sockets (one stereo, one mono) allow either series, parallel or stereo connection to two loudspeakers in a single enclosure. When the “Parallel” socket is used alone, the switch contacts in 42  Silicon Chip the “Series” socket remain closed and those in the “Parallel” socket open. This results in “Speaker 1” and “Speaker 2” being connected in parallel. Note that if a stereo plug is used in the “Parallel” socket, the ring and sleeve will be shorted together. When the “Series” socket is used alone, the switch contacts in the “Parallel” socket remain closed and those in the “Series” socket open. This results in the two speakers being connected in series. If a stereo plug is used, the ring is left open circuit. Stereo operation The two sockets can also be used simultaneously to provide a stereo drive signal to the enclosure, with each signal driving one of the speakers. In this case all switch contacts in the two sockets will be open. This mode only works when using a mono plug in the “Parallel” socket because the negative connection to “Speaker 2” is made via the short created between the ring and sleeve of the plug. Warning: in stereo mode, the positive signals on the two input sockets remain isolated from each other but the negative signals are connected together. Therefore, the stereo connection should only be used when driven from a dualchannel amplifier that has a common return for the two channels. It must not be used with bridge-output amplifiers and generally should not be used with two separate mono amplifiers having individual speaker returns. In summary: (1) select either series or parallel mono operation by inserting a single plug in the appropriate socket; (2) use mono plugs in all cases (recommended); and (3) to drive the enclosure from a stereo source, always use a stereo amplifier having a common speaker return, feeding the left signal to one socket and the right signal to the other. When no plugs are inserted, all four speaker terminals are shorted together, providing the advantage of self-damping during transport. However, this will present a problem in applications where several other types of connectors must also be wired in parallel with the speakers. To use these other connectors, insert an open-circuit mono or stereo plug into the “Parallel” socket. Doing so will leave the two speakers connected together in parallel via the contacts of the “Series” socket. To completely isolate the two speakers, insert an open-circuit stereo plug in the “Parallel” socket and an open-circuit mono or stereo plug in the “Series” socket. Be aware that 6.5mm phone plugs/sockets are not the optimum solution for high-power loudspeak­ er connections, despite their use for this purpose in some applications. Additionally, note that these sockets are not airtight. If used in enclosures that require sealing, enclose the rear of the sockets in a plastic “Zippy” box or similar. Finally, be sure to label the sockets appropriately. Markings of “S” and “P” may have alternative interpretations - especially to those more inclined to culinary rather than electronic pursuits! Andrew West, Brisbane, Qld. ($40) siliconchip.com.au 3-digit LED stopwatch Here’s a fun stopwatch that counts up to 9 minutes, 60 seconds on a 3-digit 7-segment LED display. It’s driven by the Schools Experimenter board which was described in May 2005 and is still available as a kit from MicroZed Computers (www. microzed.com.au). However, any basic PICAXE-08 circuit with a programming interface, power supply and push-button switch on input3 could be substituted. The three displays are driven by 4026B decade counter/7-segment decoders (IC1-IC3). This same scheme was also used in the “PICAXE Powered Thermostat” project published in February 2006. Pressing the switch on the Schools Experimenter board resets the count to zero, while a second press starts the count running. Each pulse on the PIN2 output advances IC1’s count by one. Once its count reaches “9”, a subsequent pulse rolls the count over to “0” and generates a pulse at the “Carry out” pin. This in turn advances the following stage (IC2) by pulsing its “Clk” input. The minutes counter (IC3) oper- ates in a similar manner, although the BASIC program must execute a simple routine to advance the minutes count when the seconds count reaches 60 rather than 99! The PIN1 output is set high at the 1-minute mark and is used to drive the decimal point in the minutes display (DISP3). Note that if a piezo sounder is also connected to PIN2, the stopwatch will “tick” every second and “beep” every minute. Pressing the switch a third time freezes the count. The timing for the circuit relies on the PICAXE’s internal oscillator, which gives an accuracy of about ±1s within the 10-minute period (at 22°C). Altering any of the pause statements will cause a drift away from optimum timing. Michael Jeffery, Porepunkah, Vic. ($50) Listing: Stopwatch.bas symbol mins = b0 tick: pause 998 ready: low 1 b1 = 0 pause 250 if pin3 = 1 then reset goto ready reset: high 0 low 0 pause 200 if pin3 = 1 then start goto reset start: if pin3 = 1 then tick goto start siliconchip.com.au tick2: if pin3 = 1 then ready pause 164 goto tick3 'reset the counters minsjump: pause 140 tick3: high 2 low 2 if pin3 = 1 then ready pause 165 if pin3 = 1 then ready pause 164 if pin3 = 1 then ready 'stop if switch pressed again pause 164 if pin3 = 1 then ready pause 164 if pin3 = 1 then ready pause 165 b1 = 1 + b1 if b1 = 60 then minute goto tick2 minute: b2 = b2 + b1 - 59 b1 = 0 for mins = 1 to 40 high 2 low 2 next mins high 1 if b2 = 10 then ready goto minsjump January 2007  43 SERVICEMAN'S LOG It’s no wonder I get aggravated You would think that changing a few lamps in a car stereo system would be simple enough, wouldn’t you? Here’s what happened when Muggins tackled the job . . . plus there’s some more warranty stories from a contributor. This story started when a friend bought a secondhand 1999 Mitsubishi Pajero which had a Clarion Alpha ARX3371 Radio/Tape/6x CD635 stacker. The whole car was pretty schmick but there was no display on the radio control panel. The front escutcheon was one of those security removal types. All I had to do was undo the screws from its rear and replace the three blue and two green lamps with new ones. I assumed they were all 12V 60mA 3mm types, even though the supply measured only 9V. The higher voltage rating of the lamps helped ensure long life and the 9V versions wouldn’t be that much brighter. The lamps are obtainable from WES Components and I swapped the coloured covers from the faulty ones. When I finished, I cleaned the solder flux off with methylated spirits. I then screwed the back on the module and plugged it into the radio, only to find that the entire radio was now completely dead. And to add insult to injury, there was still no illumination. Items Covered This Month • Clarion Alpha ARX3371 Car Radio/Tape/6x CD635 stacker • • Teac TV set CT-M342HW JVC AV-29LS TV set (-AU) CH chassis • LG CT29M30V TV set (MC022A chassis) • Sanyo CP29AF2X-50 TV set (FC3-G2 chassis) 44  Silicon Chip I didn’t think I had made any mistakes on this routine bit of service so I was really annoyed at this turn of events. However, cursing wasn’t going to get it fixed, so I checked the car’s fuses and even removed the whole radio from its DIN casing to check the line fuse behind it but they were all OK. What’s more, I could still measure +9V and +5V on the connector to the detachable front control escutcheon. Thinking I must have done something wrong, I disassembled it again and checked my work but everything looked OK. The soldering on some other parts looked a bit dodgy though, so I reworked the whole board. This didn’t help and I was beginning to think I had destroyed the surfacemounted microcontroller IC in the centre of the board, perhaps by zapping it with an electrostatic charge during handling. It was time to seek help from other technicians in the industry and eventually someone gave me a small clue. On JVC and Mitsubishi car stereos, some of the so-called “tact” switches give trouble and have to be replaced, so I decided to give the switches on my panel a squirt with contact spray. Initially nothing happened when I reassembled it and tried again but then suddenly, after repeated button pressings, it began to respond intermittently. Encouraged by this, I feverishly pressed the buttons repeatedly and after a while the whole radio began working normally. So what had happened? Well, I suspect when I had used metho to clean the solder flux off the PC board, I had inadvertently contaminated the “tact” switches, so that several appeared to be on simultaneously. This in turn prevented the microcontroller from resetting and switching the set on. It’s worth recalling that during the early 1970s, many colour TVs (particularly German) used touch sensors to select channels. These consisted of two closely spaced metal plates which eventually got dirty from continuous use. As a result, the touch sensors eventually refused to work and would “stick” in an on or off position, especially on humid days. We used to clean them with a toothbrush and a solvent. However, we soon discovered that methylated spirits only made the situation worse, as it left a conductive film (it has an impurity to make it unpleasant to drink, I believe). In the end, we found that using CRC 2-26 to clean the dirt off was the best solution. The dull Teac I recently had another Teac CTM342HW come in, the owner complaining of a dull unfocussed picture with smearing. It was very apparent the picture tube had gone low emission, this being due to the fact that the filament voltage had gone way too high. The B+ rail had gone well above +110V and the reason for this was that capacitors C908 and C909 had dried out. I gave it a tickle with the CRT rejuvenator and this proved to be quite successful, except that there was no sound or picture on TV or AV. All the on-screen displays were there, however, except volume. A quick check showed that the set was not stuck in the “hotel” mode, while the remote control functions all worked. I checked the voltage rails and all were OK. I then changed C917 (100mF 160V) and all the electros on the low-voltage lines but this made no difference. Next, because the jungle IC101 (TB1238N) processes just about every­ thing to do with both sound and picture, I thought it to be a good idea to siliconchip.com.au that it suddenly decreased by 2.5V near a plastic cable tie. Scraping the PC board lacquer away revealed a fine hairline crack across the data lines and bridging this brought the set back to life. Weird interference replace it. Again, it made no difference so I then replaced the EEPROM (IC602, M24CO4B6) but it was still no good. By now, I was beginning to get aggravated – you would have thought that a cheap 34cm TV would be pretty straightforward. I then got serious and measured every pin on the jungle IC101. Most told me what I already knew – ie, that there was no sound or picture. siliconchip.com.au However, when I reached pins 26 & 27 – the I2C SCL and SDA data lines, respectively – there was only 2.5V on each whereas they should have been +5V. I then went to the microcontroller (IC601) and found +5V on pins 36 & 37. So 2.5V was going “missing” somewhere on a low current data lines. Well, you can probably guess the rest. I followed the PC pattern around past the buffer resistors until I found Mrs Thompson complained that her 2001 JVC AV-29LS (-AU) TV set (CH chassis) was getting all sorts of weird interference. When I arrived, the set was already switched on and I was able to observe ringing and a buzzing noise in the sound, both on TV and AV. I was pretty sure that this was a problem with the TV itself and decided to take it back to the workshop to confirm this. However, when I subsequently switched it on back at the ranch, both sound and picture were excellent and it initially looked like I had misdiagnosed the problem. Fortunately, as the set warmed up, the symptoms started to show. And the longer the set was on, the worse it got, the symptoms indicating a problem in the power supply. I removed the back and decided to give the set the freezer treatment, since the problem appeared to be heat related. I got out the freezer and started blasting all over the set but there was no reaction. Nor did heating the chassis with a heat gun change the symptoms. This really was puzzling since the set was OK when cold and lousy when hot. So what was going on? The oscilloscope was definitely showing AC interference on almost all the B+ rails but especially on the +9V and +15V January 2007  45 Serviceman’s Log – continued rails, which are generated by IC974 (BA51W12ST-VS). This 5-pin IC regulator has been known to give problems when R969 (2.7W) in the output goes high but in this case, it was spot on and was totally unaffected by heating and freezing. I was about to give up on the wretched thing for the day when I noticed another capacitor across C969 to pin 2 of IC974. This was soldered underneath the chassis making it difficult to access but I still managed to give it the heating and freezing treatment. This time the response was immediate, the symptoms changing to order. Replacing the capacitor did the trick. The set was now performing OK and so we let it go at that. Self-inflicted injury A neighbour of sorts brought in his LG CT29M30V (MC022A chassis) TV complaining of no sound. He felt like a real dill because it had happened when he had incorrectly connected his DVD player to the TV monitor output AV sockets. I told him not to be so hard on himself as the TV should really have been able to handle this sort of mistake. In fact, I really couldn’t see how this could have caused damage, so perhaps there was some other problem. Unfortunately, it turned out that the set had been damaged. It had 46  Silicon Chip lost not only AV sound but also the sound when operated in TV mode. I ran my fingers over IC602 (TDA7297) while the set was on and heard buzzing noises in the loudspeaker which indicated that the audio amplifiers were still OK. However, there was no response from IC661 (MSP3460G), the 52-pin sound processor. This IC is fed by three voltage rails (9V, 5V and 3.3V) to five different pins. I checked these and found that pin 33 was very low at +2V when it should have been at +8.2V. The 9V rail was OK as was R629 (91W), so suspicion fell on 8.2V zener diode ZD610 which I replaced. This made no difference and it was only when I desoldered pin 33 that the voltage rose to 8.2V. Replacing the IC fixed the problem. I can’t explain why the IC blew when the DVD was connected to the monitor outputs, especially as they are capacitively-coupled to the IC. I wasn’t game to try it again but I checked the capacitors as being OK. Disgruntled customer A testy Mr Brentwood brought in his 2004 Sanyo CP29AF2X-50 TV set which uses an FC3-G2 chassis, complaining that it was dead. He was somewhat belligerent about it as the set was only just out of warranty. When I got to examine it, I found that everything looked pretty well OK but the set just wouldn’t start. I spent a great deal of time following various red herrings until I tried disconnecting the CRT board, after which the set finally fired up. Believing I was now on the home run I checked or replaced almost every component on the CRT board, which uses a TDA6103 video output IC. I have written before about a zener diode on pin 5 on the VIP line but this set doesn’t have a feedback rail to the jungle IC. Unfortunately, this work made no difference and after a long time I eventually conceded there was nothing wrong with the CRT board or the CRT. What I did eventually discover was that there is a “protect” line coming off the CRT heater supply from the flyback transformer. This line has a zener diode D476 in series with it and replacing it allowed the set to come on and give sound and picture. Unfortunately, this also revealed that the picture was too large and overscanned the CRT, even though the B+ was spot on at +130V. Once again, I carefully examined the EHT section, especially the tuning capacitors on the collector of line output transistor Q432 but nothing showed up as faulty. I then realised I had fitted a 6.2V zener diode for D476 instead of the correct 6.8V type. However, fitting the correct part reproduced the original fault. I then checked the original zener diode out of circuit to find that it was perfectly OK. By now I was getting aggravated again so I took a short break. When I returned, I decided to check the EHT only to find it was very low at about 15kV. The tuning capacitors were all OK, so I figured it had to be the flyback transformer. A new one completely fixed the problem but Mr Brentwood wasn’t happy about the cost. More warranty stories Finally, here are some more interesting warranty stories from a contributor in response to my stories in the September 2006 issue. I’ll let B. W. tell them in his own words: I have long been involved with the electric (rather than the electronic) side of servicing and can well and truly identify with the stories told in Serviceman’s Log for September 2006. First, some advice to those who are siliconchip.com.au bringing in a “Tool In A Bucket” (the common way of bringing in a tool in pieces). If you have to present a tool in this condition, at least let the (mostly male) staff have a bit of enjoyment and spare yourself some embarrassment by finding a young lady, preferably blonde, to deliver the tool. The less the deliverer knows of the tool’s history, the better. The repairer will have to work from the exploded parts diagram and, depending on the time taken, you will may be charged 60-75% of the new tool cost. Even then, the repairer will not be making a huge profit! A variation on the “Tool In A Bucket” is where the customer opens with “You got brushes, mate?” Invariably, he then produces a badly worn set of brushes. “What are they out of?” “A drill!” “What brand and model?” “Dunno. Let me see what you’ve got and I will pick the correct type!” If only it was that simple. Makita, for example, use about 100 different brush sets which vary in composition as well as size (depending on current and voltage requirements). In addition, some brushes have leads of varying types and some have springs integrated with the brush. And some even have “safety cut-outs” for the upmarket professional tools, so he has no hope of choosing the correct type. We were warranty agents for six other brands as well and almost all the brushes are packed in identicallysized boxes. Often too, the customer’s brushes will show severe arcing on one side, so the armature is also U/S. In fact, we have sold brushes where the customer knew the make and model, only to have the customer return in a week because the new brushes have failed due to a crook armature! We had a similar experience to the generator and chain story. I sold an air compressor and then, a week later, an identical unit to the same customer. On the road, the wheels fell off the first unit, as did the pump. The tank was ruined but the motor survived without a scratch! The customer was not embarrassed but blamed it on working with a certain ethnic group who like red wine for morning smoko and for lunch! (Job sites can be cold on a winter morning!) Chainsaws? I fixed a brand new one on the counter, siliconchip.com.au January 2007  47 was severely corroded but the manufacturer said to exchange it and warn the customer to be more careful with the water. That motor also lasted three months! The manufacturer again said to exchange it, against my recommendation! Three months later, the customer was back, this time for a new mixer. The old mixer’s bowl had failed! From discussion, it turned out that he was washing oysters in the mixer and had sea water flowing through the bowl which was then sloshing over other parts. Another mixer was sold by our staff who helped to load it onto the back of a newish Ford F250 Dual Cab 4x4. The customer refused the offer of a rope to tie the mixer down. “The job’s just around the corner”, he said and off he went. Oops. Bang! I wonder how much a new rear window for a Ford F250 Dual Cab 4x4 costs. Probably more than the cost of a bit of rope I would venture to guess! Finally, one last incident from my youth! I was behind the counter of a hardware store (back in the days of real “service”), when the woman being served by another staff member said, in a loud and scornful voice, “I know these are inch, number eight screws but my husband has written that he wants WOOD screws and these are STEEL! SC I quickly left the area. Serviceman’s Log – continued in front of other customers. The purchaser claimed “Initial Failure” and I simply reversed the chain so that it ran in the correct direction! He told me that it should work either way! Drills can be another problem for some customers. Sometimes they will not get to full speed but they have no hope if the speed limiting screw on the trigger is set too low. Compressed-air nail guns do like the correct nails. It is possible, nay, likely, that a nail can be fired out the bottom of the magazine towards the user’s leg if the collation angle is for another brand of gun! And no, we do not refund on opened boxes of nails, sir! That brings me to angle grinders. The better ones have 2000W (or more) of attitude and some customers wonder why we have a policy of not servicing them unless the safety guard is in place (or unless they agree to allow us to install a new one). I know from experience that a piece off a 225mm disk can punch through a galvanised iron wall or chip a thigh bone (I believe that Monash University has rated these as the most dangerous tool in the average workshop). What about warranty? The best trick is to thrash the living daylights out of a tool and when it dies out of warranty, buy a new identical one. Then, two weeks later, you drop in the old tool and the new warranty card! After all, you can always flog off a spare tool to the apprentice or to a mate in the pub. We stop this little scam by putting the serial numbers on all warranty cards at time of sale but not all retailers do this. Lefthand threaded bolts broken off in circular saws are a constant delight. Fortunately, once the bolt breaks, the blade falls free and the stub of the bolt can then be unscrewed by hand if it is turned the correct way. This is best done on the counter, in front of witnesses, on a Saturday morning. “That’s $1.95 thanks, sir, and make sure that you remember the lefthand thread next time”. Some modifications can be downright dangerous. Double-insulated tools lose a certain something when a hole is drilled in the case and a bolt put through to hold the switch in place! After all, a few millimetres of air between the bolt and the Active terminal really upsets the double insulation specification. We recently sold a cement mixer and the customer brought the motor only back within three months. It Looking for real performance? NOT A REPRINT – Completely NEW projects – the result of two years research & development • Learn how engine management systems work • Build projects to control nitrous, fuel injection and turbo 160 PAGES 23 CHAPTE RS Fro m the pu bli sh ers of boost systems • Switch devices on and off on the basis of signal frequency, temperature and voltage Intelligen t turbo timer • Build test instruments to check fuel injector duty cycle, fuel mixture and brake and coolant temperatures • Speedo Corrector, Turbo Timer & Digital Thermometer Projects I SBN 095 852 9 7809 5 8 5229 4 $19.80 (inc GST) Mail order prices: Aust. $A22.50 (incl. GST & P&P); Overseas: $A26.00 via airmail. 294 - 4 TURBO B OOST & ni trous fuel 6 NZ $22.00 (inc GST) controllers How eng in managemene t works Order by phoning (02) 9939 3295 & quoting your credit card number; or fax the details to (02) 9939 2648; or mail your order with cheque or credit card details to Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. 48  Silicon Chip siliconchip.com.au Radar Speed Indicator Kit Ref: Silicon Chip November 2006 This Doppler radar gun reads speed in km/h or mph up to 250 km/h or 155 mph. It has a resolution of 1 km/h or 1 mph with an accuracy of 1%, and also has a hold switch so you can freeze the reading. There's a Jiffy box to mount the electronics in, and the enclosure for the radar gun assembly is made from 2 x coffee tins or similar. Details included. Kit includes PCB and all specified components. • Requires 12VDC. DVR with Dome and Weatherproof Colour Cameras The DVR is fitted with a 250GB hard drive, can accommodate up to 4 cameras with power derived from the DVR and will allow you to record and view up to 4 cameras simultaneously. This package includes the DVR with a dome and outdoor IR camera with bracket, mounting hardware, power supply, 14m camera connect cable, software, USB interface lead and user manual. Cat. KC-5429 $ 95 Cat. QV-3085 $ 00 99. Dual Channel Wireless UHF Microphone Car Air Conditioner Controller Kit The unit features two Diversity separate Type channels, one for each microphone. Output is either via separate balanced XLR socket, one for each channel, or via an unbalanced line with the two channels mixed. The system includes 2 microphones Cat. AM-4078 and batteries, receiver unit, 14VDC $ 00 plugpack and one metre 6.5 mono plug to 6.5 mono plug lead. 199. Golf Driver AM/FM Radio The perfect desk accessory for the golf enthusiast. This AM/FM radio not only has a stainless steel front but also a real golf ball and tee. The driver's shaft controls the volume and channel selection. • 245(L) x 125(W) x 113(H)mm Cat. GH-1882 • Batteries not included $ 95 19. New Store in Denedin NZ! 1 Lees St. Kensington Dunedin NZ Ph: (03) 4717 934 NOW OPEN! 999. Ref: Silicon Chip January 2007 This kit stops the air conditioner in your car from taking engine power under acceleration. It will allow the compressor to run with low throttle even when the cabin temperature setting has been reached and will automatically switch the compressor off at idle. It also features an override switch and an LED function indicator. Kit supplied with PCB with overlay and all electronic components. Cat. KC-5437 • Recommended box $ 95 UB3 HB-6013 39. Electronic Photo Frame Plug in your data card and choose how you want your photos displayed: multiple images in a slide show, a single image or thumbnails. You can also play a sound track for accompaniment, show video clips or print your photos on a compatible printer. The frame has a brushed silverlike finish and can be wall mounted, or displayed on a table in landscape or portrait view. Remote control with battery and 12VDC plugpack included. • Dimensions: 238(L) x Cat. QM-3759 SAVE 184(H) x 40(D)mm $ 00 $50 Was $299 Its massive 100W transducer produces millions of bubbles small enough to penetrate the most microscopic of crevices, cleaning them thoroughly. Use this cleaner for automotive injectors, jewellery, glasses, circuit boards and more. The unit features a large display with real time count down and an easy to operate cleaning duration setting at 5Cat. YH-5410 minute increments. Tank dimensions: $ 00 265(L) x 160(W) x 100(H)mm 299. Solar Powered Garage LED light Ideal for garages, gazebos and greenhouses, the 360° adjustable solar panel will allow for custom positioning. It's waterproof, features a cord-switch to operate, and is simple to install. Pack includes solar panel and mounting bracket, 2.4m cable and rechargeable enclosed Ni-Cd battery. Cat. SL-2715 $ 95 39. Blue LED Analogue & Digital Clock The segments are 48mm high and consists of 3mm LEDs. The 200mm diameter display contains 60 x 5mm high intensity LEDs on a 60 second illuminated circuit. Every second one LED will power down until the face is no longer illuminated and the process starts again. • Measures 250(L) x 250(H) x 50(W)mm Cat. AR-1788 • Plugpack supplied $ 95 99. Protect and Extend the Life of Your Power Tool Rechargeable Batteries Ref: Silicon Chip December 2006 Enhance the performance of the charger supplied with your power tools with this fantastic controller. It incorporates charge timeout, min and max temperature monitoring, Delta V charge detection, power and charge LED indicator and more. Suits both Ni-Cd and Ni-MH cells. Kit includes PCB Cat. KC-5436 with overlay, case and all $ 95 electronic components. 39. 249. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 High Power Ultrasonic Cleaner INTERNET> www.jaycar.com.au 1 Rootin' Tootin' Quick Fire Shootin' Game Save on USB Peripherals! Clean up the saloon and get rid of the bad guys with this infrared shooting game. It works just like a real pistol range and includes batteries. Was $79.95 Wireless USB Rechargeable Mouse Cat. GT-3133 $ 95 SAVE $15 64. 29. $10 USB Mouse with Laser Pick-up 800dpi resolution, that's double the resolution of an optical mouse! This reduces the strain on hands and wrists by minimising the movements required to move Cat. XM-5133 $ 95 the cursor. Was $39.95 Desktop Finger Drum Kit Practice your drumming moves in those 'quiet' office moments. It has 2 toms, a snare, kick drum and cymbal. Play freestyle with your fingers or use the preCat. GE-4080 recorded demo track or even $ 95 record your own grooves. 29. Twin-Pack 38 Channel UHF Mini CB Radios SAVE $10 This pack of 2 mini UHF CB communicators can keep you clearly in touch up to 3km. They feature electronic volume control, monitor functions and an integrated blue LED torch. • Each unit requires 3 x AAA batteries See our full (not included) Cat. DC-1005 range of UHF CB $ 95pr radios in-store! Travel Shaver SAVE $10 Perfect for laptops or limited workspaces. Was $39.95 Cat. XM-5134 $ 95 19 Key Numeric Keypad 29. Great for laptops! One key feature that doesn't come with a laptop is the numeric keypad. This unit is compact, 'plug and play', and only measures 67(W) x110(L) x20(H)mm. • Keypad lead length Cat. XC-5155 700mm $ 95 Was $29.95 SAVE $10 19. 49. PC Companions Includes an MP3 player, webcam and digital voice recorder complete with the assured picture quality of a 6.6 megapixel video or still shot. The unit has a rotatable 38mm LCD with 16MB of internal memory and accommodates an SC/MMC external memory card. All interface leads and SAVE software supplied. $20 • Requires 4 x AAA Cat. QC-3234 batteries (not included) $ 00 Was $299.00 279. USB Optical Mouse with Retractable Lead 29. The razor is housed in a sturdy case that is easily removed to reveal the razor and a compact illuminated mirror. Great for planes, trains, and automobiles. • Cleaning brush and batteries included • Dimensions: 62(W) x 103(H) x 25(D)mm Coughing Lung Ashtray This is sure to help you give up. Each time you put down your cigarette the ashtray coughs and splutters to remind you how bad smoking is for you health. Cat. GH-1330 $ 95 Connects to your USB port and headphone jack to deliver a 4-port hub with a multimedia speaker. When its head is detached from the body it converts to portable FM radio that you can take anywhere. • Requires 2 x AA batteries for portable radio use (not Cat. XC-4844 included) $ 95 • Approx. 85mm high 19. Solar Powered Calculator with 3 Port USB Hub Talking Alarm Clock with Touch Light This talking clock with nightlight will illuminate and tell you the time all with one simple touch. It has a stylish mouse shaped design. • LCD panel 21(L) x 13(H)mm Cat. XC-0142 • Measures 80(L) x46(H) x 23(W)mm $ 95 • Battery included 14. Rev-Olution Rev Counter Alarm Clock USB Missile Launcher Miniature Golf Buggy with LCD Alarm Clock SAVE 49. This miniature 1:18 scale golf buggy with clock will make a cherished gift for any golf enthusiast. The windshield is an LCD screen which has full clock functions with a calendar and temperature setting. • 2 sets of miniature golf clubs • Measures 140(L) x 75(W) x 100(H)mm SAVE Was $24.95 $5.00 A great gift for the unrepentant smoker! Octopus Massager This super-car inspired alarm clock has full clock functions in a stylish design. You will be amazed at the true V8 engine sound of the alarm. • Mains power supply included Cat. AR-1784 • Size: 130(W) x 175(D) x 100(H)mm $ 95 Connected to your USB $10 port the software will allow you to navigate the missiles trajectory, pan 180°, tilt up to 45° and provide realistic sound effects. The missiles are made from soft foam so it's safe to use at home or Was $59.95 in the office. • Not suitable for children. Cat. GE-4072 • Replacement missiles available $ 95 GE-4073 $6.95 pkt 3 19. Relax and Unwind It features a standard calculator with functions for financial calculations and connects to your laptop or workstation for use as an external numerical Cat. XC-4846 keypad. It's also a 95 passive 3 port USB hub. $ 39. Cat. GH-1515 $ 95 9. Innovative Clocks Dog Shaped USB Hub and Radio 2 The pack contains a retractable charger to ensure the mouse batteries are topped up. Was $39.95 Cat. XM-5132 SAVE $ 95 6.6 Megapixel Digital Video Camera 49. Simply press the button on its head to activate the vibrating tentacles and the massaging begins. Great for the back, neck, shoulders, legs and arms. Batteries not included • 125mm tall Cat. GH-1752 $ 95 6. Massager Seat Cover with Heater Enjoy some holiday relaxation with this relaxing back massager. Ideal for the home, office or even in the car. • 6 Massage motors with 3 intensity levels • Mains adaptor and cigarette socket plug included Cat. GH-1754 $ 95 49. Water Fountain with Six Nature Sounds Cat. GH-1880 $ 95 19. Relax and unwind to the sounds of nature accompanied by the soothing sound of flowing water with mesmerising colour changing background lights. • Mains adaptor included • Measures 190(L) x 330(H) x Cat. GH-1820 165(W)mm $ 95 59. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au Kevlar Cone Coaxial Speakers This range of coaxial speakers offer high performance and great looks. They have a large super tweeter and their Kevlar cones take them into a realm of their own. 4" 2 Way • 40WRMS power • 86.5dB sensitivity 5" 2 Way • 50WRMS power • 89.5dB sensitivity 6.5" 2 Way • 75WRMS power • 91.3dB sensitivity 6" x 9" 2 Way • 80WRMS power • 93.5dB sensitivity Cat. CS-2320 99.95 $ Cat. CS-2322 109.95 $ This unit supports two AV devices connected to the transmitter and allows you to switch between them. With this unit you can feed as many receivers as you like. Includes built-in IR remote control repeater, selector switch, AV leads, power supplies and instruction manual. Note: This unit does not simultaneously broadcast two signals Cat. AR-1846 $ 95 119.95 $ Cat. CS-2328 Additional receivers AR-1847 $69.95 139.95 $ 5.8GHz Wireless Audio Video Sender Install proper marine-grade speakers in your boat and they will still sound good long after ordinary car speakers have died. Cat. CS-2390 • 4" Dia. $ 95 • 20WRMS Power 49. Wireless MP3 Modulator for Vehicles SAVE $10 Use any ordinary USB flash drive to store your favourite MP3 files and play them through your car's FM radio. 59. Two Channel Input 2.4GHz Wireless Audio Video Sender 129. Cat. CS-2324 2-Way Marine Speakers Cat. GE-4030 $ 95 Watch Cable TV in another room! Wireless LAN, Bluetooth, 5.8GHz cordless phones, etc, The uncluttered can cause overcrowding AV band! and interference for items that transmit on the 2.4GHz band. Beat the congestion with this 5.8GHz unit and ensure crystal clear reception no matter what audio video device you choose. Complete with built-in IR remote control repeater, AV leads, power supplies and instruction manual. Cat. AR-1840 Additional receivers now $ 00 available AR-1841 $159.95 249. Was $69.95 Car Amplifiers Our amplifiers have taken pole position for two consecutive years in Car Stereo Australia's Product of the Year Awards. We have an amp to suit every application. See our website for all the great features! Get that Party Pumpin'! 15" Party Speaker Buy two for $270 This speaker provides great Save $28! performance in difficult locations such as tents or halls. The unit consists of 3 piezo drivers and a 15" bass driver in a sturdy box. Termination to the box is via high quality gold plated binding posts. Cat. CS-2515 • Power 120 WRMS $ 00 • Dimensions: 740(H) x 505(W) x 350(D) mm 149. Check out more of our amps in-store! Rated at a generous 100WRMS per channel, this two channel amplifier features a microphone input and quality screwdown speaker terminals. See our website or catalogue for full specifications. Cat. AA-0470 $ 00 2 x 80WRMS 2 x 80WRMS <at> 4 ohms 2 x 100WRMS <at>2 ohms 1 x 200WRMS <at> 4 ohms Cat. AA-0420 $169.95 4 x 50WRMS 4 x 50WRMS <at> 4ohms 4 x 80 WRMS <at> 2ohms 2 x 160WRMS <at> 4 ohms Cat. AA-0422 $199.95 2 x 150WRMS 2 x 150WRMS <at> 4 ohms 2 x 255WRMS <at>2 ohms 1 x 500WRMS <at>4 ohms Cat. AA-0424 $249.95 2 x 100 WRMS Stereo Amplifier with Remote Control 199. 4 x 100WRMS • 4 x 130WRMS <at> 4 ohms • 4 x 190WRMS <at> 2 ohms • 2 x 380WRMS <at> 4 ohms Cat. AA-0426 $299.95 800WRMS Class D 1 x 400WRMS <at> 4 ohms 1 x 700WRMS <at> 2 ohms 1 x 820WRMS <at> 1 ohm Cat. AA-0428 $399 DJ Dual CD Player Enclosed in a rugged, rack mountable chassis it features 8 times over sampling 1 bit D/A converter, 3 different scan speeds, pitch display, seamless loop, 25- Cat. AA-0490 second anti-shock, auto locking $ 00 CD drawers and more! FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au 399. HDMI Leads and Accessories High definition multimedia interface (HDMI) provides high quality signals for the best in reproduction quality. Male to male connection WQ-7400 1.5m $39.95ea WQ-7402 3.0m $49.95ea WQ-7404 5.0m $64.95ea WQ-7405 10m $99.95ea HDMI to DVI Cable WQ-7406 3.0m $39.95ea HDMI Adaptors PA-3640 HDMI Socket to Socket $14.95ea PA-3642 HDMI Plug to DVI-D Socket $14.95ea PA-3644 HDMI Plug to DVI-D Plug $14.95ea Portable Speaker This nifty little unit is compatible with iPods, MP3 players, mobile phones, portable CD players, laptops and PCs. It folds into a tiny 90(L) x 65(H) x 60(W)mm compact box and weighs only 177g. Was $29.95 SAVE $15 iPod® not included Cat. XC-5186 $ 95 14. Weatherproof Amplified Speaker with Solar Charger This solar/battery powered wireless remote speaker system enables you to listen to radio, MP3, TV sound, music etc. away from the house. It transmits audio from the house to the speaker up to 50m away on a quiet 900MHz band. • Rechargeable batteries included • Charged via mains plugpack or in-built solar panel Was $199.00 • Speaker/Receiver: 240(Dia.) x 340(H)mm excluding carry handle SAVE $20 Cat. AR-1899 $ 00 179. Audio Test Equipment Compact Digital Sound Level Meter Featuring a wide dynamic range from 30 to 130dB, it can measure both A and C weightings and can have fast or slow response to get an 'ambient' reading or a short noise. Includes data hold and min/max functions, as well as tripod mount. Supplied with carry case, battery, and wind sock. Cat. QM-1589 • Dimensions: 210(H) x $ 95 55(W) x 32(D)mm 99. Roadies Cable Tester This rugged unit will enable quick, convenient and reliable continuity testing of most popular audio cables such as balanced XLR, phono, Speakon, DIN and more. • Requires one 9V battery (not included) Cat. AA-0404 • Measures 102(W) x $ 95 45(H) x 142(D)mm 39. 2.7GHz Frequency Counter A 10Hz to 2.7GHz dual range frequency counter for measuring functions of frequency period totals and self-checking. The counter readout has a large 10mm 7 segment LED display with gate time and data hold function. Decimals are also included as well as a single step input attenuation to a factor of 20 and a Cat. QT-2202 low pass filter. See website or $ 00 catalogue for full specifications. 199. 3 Rechargeable LED Work Light It has a strong magnetic mount, twisting handle and hanging hook. This robust unit has two lighting options, 1W LED for use as a torch, 30 LEDs for use as a lamp and is supplied with mains and car chargers. • Measures at 360 x 45 x 55mm Cat. ST-3024 $ 95 39. 10M Candle Power Rechargeable Spotlight Features a super powerful 100W halogen globe, a switch for dim lighting, and twin fluorescent globes for reading or as a work light • Replacement Globe: SL-3223 $12.95 Cat. ST-3308 • 12V SLA battery and $ 95 chargers supplied 79. Pivot Head LED Lantern The 20 LED lamp has a 2 mode operation so you can set the degree of illumination from a low level reading lamps to a ultra-bright lantern. The head pivots 180° for full versatility. • Requires 3 x D batteries (not included) Cat. ST-3053 $ 95 24. USB Colour Changing LED Lava Lamp Give your office a bit of novelty lighting. Easily connected to any USB port the lamp will instantly change colours Cat. GH-1520 enhancing even the dullest $ 95 office. • 170mm high 14. These rugged yet attractive garden lights are diecast, powdercoated and moisture sealed with neoprene gaskets. They're powered by 12VDC and accept a halogen See our full MR16 globe. See in-store and range of garden lights in-store check our bulk quantity prices, transformers and globes to suit. Focal Highlighter Enhance a particular plant or garden feature. • 100(H) x 96(Dia.)mm Cat. SL-2772 excluding spike $ 50 22. Flush Mount Garden Light This sturdy lamp is ideal for stairways or decks and can be walked on. Cat. SL-2776 • 100(H) x 95(Dia)mm $ 50 22. Wall Mount Garden Lamp Ideal for lighting a path, step or stairs • 100(Dia.) x 50(D)mm Cat. SL-2778 $ 75 16. 4 SAVE $20 1-Watt LED Headtorch It has a water resistant case, is extremely light and comfortable to wear and is ideal for wet environments such as night fishing, caving or wherever bright light is required. An adjustable headpiece enables you to direct the beam at the Cat. ST-3321 required angle. Was $69.95 $ 95 • Batteries not included Encased in a clear tube, mount these inside a computer tower case, a show car or in cabinets etc. They are 12VDC powered, supplied as a pair and come complete with adhesive mounts, pre-wired switch and a pre-wired inverter with a 280mm long cable to the tube and a 540mm power cord terminated to a standard computer hard drive plug/socket assembly. 49. HID Rechargeable Headtorch Nothing comes close to a High Intensity Discharge (HID) torch for power and brightness. This unit More HID torches available serves as a hand or headlamp in-store and will run continuously for over 115mins on a single charge. It is waterproof (IP54 rated) making it ideal for emergency services personnel such as rescuers and fire fighters. Cat. ST-3366 $ 00 Car and mains chargers supplied. 399. Economy Headtorch With a total of 12 LEDs and 4 lighting modes it is light, compact, very efficient on batteries and comes with a fully adjustable head strap. • Batteries not Cat. ST-3286 $ 95 included • Available in three colours: SL-2855 White SL-2856 Blue SL-2857 UV Contemporary in design and fascinating to watch, this desk lamp will definitely create a focal point in any room with its wavy stainless steel stand and 3 colour changing LED balls. • Stands 470mm high SAVE • AC adaptor included When darkness falls, these spotlights switch on automatically. They have high-intensity LEDs and a built-in solar panel to charge the internal batteries during the day. Three styles are available including constant illumination and a PIR operated motion-sensing model. Stainless Steel Solar LED Spotlight • 11 LEDs • Illumination duration: 10 hours Cat. SL-2714 $ 95 Party Lighting 4-Way Light Chaser with Sound Modulator SAVE $10 Simple but effective! When music is playing, it switches in time with it. There are no modulation controls, but it works quite well indeed. It uses 240V 60W ES reflector lamps, supplied with a red, yellow, Cat. SL-2942 green, and blue globe. Check out 95 our website for replacement globes. $ Was $69.95 Red Laser Light Show Solar LED Spotlight with PIR Motion Sensor Projects a dazzling laser display onto a wall. • Requires 4 x AAA batteries (not included) • Dimensions 135 (W) x 55 (H) x 90 (D) mm • Can be powered by a 6V DC power supply (use MP-3145 $19.95) • 30 LEDs • Illumination duration: 20, 40, or 90 sec. PIR controlled • PIR Sensing range: 15 metres Cat. SL-2924 $ 95 69. Green Laser Light Show Cat. SL-2718 $ 00 99. Polycrystalline Solar Panel 129. Cat. GH-1812 $ 95 59. 49. Cat. SL-2716 $ 00 $5 34. Solar Lighting • 30 LEDs • Illumination duration: 10 hours • Polycrystalline solar panel All Types 29.95pr $ Colour Changing 3 Sphere Desk Lamp Was $39.95 9. Outdoor Lighting Effects Illuminate Your Garden 300mm Cold Cathode Fluorescent (CCFL) Lighting Kits Headtorch Heaven It has 100 pre-set geometric patterns and three modes of operation. It can be set to autocontrol so the patterns change randomly, or to the beat of the music and the speed and shape of the pattern can also be adjusted. Mains power supply and mounting Cat. SL-2937 95 bracket included. $ 169. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au H-Racer Hydrogen Car Kit with Solar Refueling Station All you need is water and sunshine. This palm-sized car has an on-board hydrogen storage tank, a fuel cell system connected to the car's electric motor, and a hydrogen refueling system linking the car's storage tank to the solar-powered refueling station. TIME Magazine's Includes product of the Hydrogen year! Fuel Cell! Cat. KT-2529 $ 95 179. 1000VA Uninterruptible Power Supply Protect your valuable computer system from power failures, preventing data loss or corruption. The included software can be set up to save your data and close down your computer automatically if the power fails. The UPS is supplied with two 12V 7Ah SLA batteries, USB interface cable and software. • 600VA UPS also available MP-5200 $129.00 Cat. MP-5202 $ 00 Wind Generators 200 Watt Wind Turbine Generators 12V and 24V models available. They will generate 200 watts at wind speed as low as 8 metres per second and will deliver useful power with a gentle 3 metre/sec breeze or give up to 300 watts at higher wind velocities. The 71kg units feature a 3 phase permanent magnet alternator with a serious 2.1 metre diameter 3 blade rotor. The units will withstand wind speeds of 40m/sec (144km/hr). Some skill is required in construction e.g. concreting, mechanical assembly and rigging. • Units are shipped in three boxes, with a combined weight of 86kg. NB. Due to the weight and size not all stores will have these in stock. The store can order the unit for you and have it delivered to your site (freight costs are additional). See our website or catalogue for further specifications. 12V Model Cat. MG-4512 24V Model Cat. MG-4510 Both Types (ea) $ 00 499. 199. Battery Chargers Battery Charger and Test Station Test, diagnose and charge Ni-Cd, NiMH rechargeable batteries and an extensive range of button cell and other batteries. Caters for up to 6 x AAA or AA cells, up to 4 x C or D Cat. MB-3548 cells in addition to 1 or 2 x 9V $ 00 block batteries. See website for battery listing and further details 149. 16 Amp 12V Car Battery Charger This fully automatic, switchmode car battery charger utilises a four stage rapid charge design to optimise the life and performance of leadacid/GEL batteries. Includes a top mounted carry handle and cable storage for the battery leads and clamps. Size: 270(W) x 220(H) x 120(D)mm. Cat. MB-3620 SAVE $ 00 Was $20.95 $189.95 169. 12VDC & 240VAC Battery Charger with LCD Recharge up to four AA, AAA, C, D and 2 x 9V Ni-Cd or Ni-MH batteries together for a total of 6 batteries. Powerful enough to get modern day high capacity Ni-MH batteries charged quickly and the ability to charge most Cat. MB-3545 battery types. $ 95 • Mains power supply included 59. Solar Panels Each panel has an array of 36 polycrystalline cells that can charge 12V batteries in virtually any climate. They are built to last, and designed to withstand a 25mm hail stone travelling at terminal velocity. They are mounted in an anodised aluminium frame that is weatherproof and corrosion resistant. See website for full details. • 10 year warranty on 10 and 20 Watt panels • 20 year warranty on 80 Watt panel Power Cat Was Now Save 10 Watts ZM-9060 $249 $169 $80 20 Watts ZM-9062 $399 $269 $130 80 Watts ZM-9069 $899 $769 $130 Amorphous Solar Panels These offer excellent quality and value for money. Beware of cheap amorphous solar panels which will simply not give the claimed output power. All supplied with lead to battery clips and plastic corner protectors. Voltage 6 Volt 12 Volt 12 Volt 12 Volt 12 Volt Power 1 Watt 2 Watt 4 Watt 10 Watt 15 Watt INTERNET> www.jaycar.com.au Cat ZM-9020 ZM-9024 ZM-9026 ZM-9030 ZM-9045 Charge that digital device, iPod, PSP or mobile phone anytime, anywhere. The pack is charged via USB and includes 7 output adaptor plugs to suit the most popular digital devices. • See website or in-store for compatible digital devices. iPodTM not included Cat. MB-3300 $ 95 69. Mains Adaptor for USB Powered Appliances Charge a USB device without the need to connect it to your computer. A switchmode adaptor with 5VDC output and 1A maximum current draw. • USB cable sold Cat. MP-3450 separately. $ 95 19. 600W (1500W Surge) 12VDC to 230VAC Inverter Features fan assisted cooling, and with all our inverters, electrical isolation for safety. This inverter is capable of recharging power See our huge tool batteries, range of running fans and lamps up inverters in-store! to 600W. Cat. MI-5108 Was SAVE $ 95 $249.95 $70 179. Portable Power! Save on BP Solar Polycrystalline Solar Panels FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 Battery Back-up Pack Price $29.95 $39.95 $69.95 $139.00 $199.00 Automotive Laptop Power Supplies They have a 12 to 13.8V input voltage, feature a recessed voltage selector, LED power indicator and are supplied with 7 output connectors for all major laptop brands. • Compatible brands include: Apple, Compaq, Del, HP, IBM, ACER, Sharp and Toshiba • Terminates to a fused 10 amp automotive cigarette lighter socket MP-3463: 15/16/18/19/20/22/24VDC Cat. MP-3463 $ 95 <at> 3.5 amps MP-3467: 15/16/18/19/20VDC<at> Cat. MP-3467 6 amps 22/24VDC<at> 5 amps $ 95 39. 69. High End Jump Starter It has a built-in 17Ah battery to jump-start your car, a cigarette lighter outlet for use as a auxiliary power source, test button with voltmeter and a work light. Recharging this power pack is via the supplied plugpack. • Extra long 850mm heavy-duty cables • Dimensions: 330(W) x 380(H) x 100(D)mm Cat. MB-3596 $ 95 79. 5 Colour Video Doorphone with 4 Camera Inputs With this system up to 4 standard CCTV cameras can be utilised without the need for a second monitor. The supplied external CCD camera is cased in a tamper proof enclosure and features IR illumination for night viewing. The internal monitor has a clear 5” colour LCD which can accommodate a door strike release (LA-5078 $44.95). • Package includes: one camera, one Cat. QC-3614 monitor with 4 camera inputs, power $ 00 supplies and mounting hardware. 599. Passive IR Camera Utilising passive infrared (PIR) for motion detection, this 350TV line camera can be used as an accessory for an alarm system or as a Sony stand-alone monitoring device. sensor The camera has a Sony sensor inside and operates from 12VDC. • PIR detection range: 100 º with 10m • Size: 70(W) x 110(H) x 49(D)mm Cat. QC-3557 $ 00 199. 2 Channel Wireless Intercom This intercom plugs into your power point and sends audio signals to another room. It has a monitor function and additional units can be added for a multi-point intercom system. • Sold as a pair Cat. AI-5500 Was $74.95 $ 95 49. This versatile B&W CCD Camera utilises a 1/3" Samsung image sensor and can SAVE accommodate either a $20 fixed or auto-iris lens of both C and CS type. The unit includes a high sensitivity microphone and has Cat. QC-3310 a range of mounting options $ 00 available. Was $99.00 79. Flickerless Colour CCD Camera with Audio SAVE $50 Delivers a flickerless digital colour image via a Sony CCD image sensor. Suitable for high-end surveillance installations, the flickerless ability of this camera makes it ideal for applications that demand a high quality, stable, and no compromise picture. Also features a high sensitivity Cat. QC-3309 microphone plus auto iris lens $ 00 controller. Was $199.00 149. Mounting adaptors included. SAVE $25 Variable Focal Length Hi-Res Camera This 470TV line camera features a Sony 1/3" HAD CCD sensor with auto iris and auto white balance. It has backlight compensation and Cat. QC-3516 operates on 12VDC or 24VAC. See $ 00 website for full specifications. • Dimensions: 60(L) x 52(W) x 48(D)mm 369. Colour CCD Dome Camera Cat. QC-3292 $ 00 99. Surveillance Camera with DV Capture A surveillance camera with built-in digital recorder! Capture events in real time will this simple to install, fully portable 380TV line VGA camera that can be either mains or battery powered. It has continuous motion detection record options and has 64MB of flash memory. Mains power supply and Cat. QV-3092 mounting hardware supplied. See $ 00 website for details. 349. 6 B&W CCD Camera with Audio Lenses to suit our Professional Range of Cameras SAVE New Security Cameras This affordable 350TV line dome camera has a Sharp CCD sensor and is ideal for shop surveillance applications. • 100mm diameter, 60mm high Monthly Security Savings QC-3315 4mm QC-3316 6mm QC-3317 8mm Was $29.50 $9.55 All Prices (ea) $ 95 19. TV/Video Resolution Chart Test the performance of complete imaging systems by creating an image of the standard resolution target in the chart and then determine the point at which the system is no longer able to separate the lines. • Chart size is 245 x 184mm, active measurement area is 204 x 152mm Cat. BJ-6025 $ 95 9. Multiplexing Digital Video Recorders The vast array of features include 250GB HDD, MPEG-4 compression for image clarity, motion detection, covert recording, alarm trigger recording, time/date stamp, image water marks and more! Connect the device to a network and utilise your recording system from anywhere with web access. The unit also supports GPRS that will allow a mobile phone to control PTZ motion and to access images. See our website or catalogue for full specifications. Available in a 4 and 16 channel 4 Channel QV-3071 Cat. QV-3071 $ Was $899 16 Channel QV-3076 Cat. QV-3076 $ 2299 Digital Video Capture Digital Video Recording PCI Cards with MPEG 4 They incorporate high speed real time compression and digital motion detection, alarm event recording and logging, variable compression, and mixed frame rate recording. The surveillance images can be accessed remotely via a LAN, WAN or the Internet. Available in 4 and 8 channel. 4 Channel 8 Channel Cat. QV-3082 Cat. QV-3080 $ 00 $ 00 249. 399. 4 Channel Multiplexing DVR with Weatherproof Colour IR Cameras View and record 4 video channels at once. The 4 colour cameras have IR illuminators for night use and are weatherproof. Comes fitted with a 250GB HDD, but supports up to 400GB hard drives and the cameras are all powered from the DVR. The pack includes 4 colour IR cameras, power supply and all cables. See website for SAVE full specifications. Cat. QV-3070 $100 $ Was $1299 SAVE $100 799 SAVE $100 Was $2399 Wireless Surveillance Wireless IP Camera with Infrared LEDs This compact camera has a built-in web server and will provide worldwide video coverage via the Internet or your LAN. It has 6 IR LEDs for night vision, focal adjustment and has motion detection software to allow for automatic intruder detection. The camera is supplied with a mounting bracket, software and mains power adaptor. See website for full specifications. Cat. QC-3398 $ 00 • 320 x 240 recording resolution 349. Weather Resistant Wireless Digital Colour Camera This camera has 420TV line resolution, 27 IR LEDs for night viewing and includes a mounting bracket and power supply. Use this camera with any of our 2.4GHz wireless receivers. Under eave Cat. QC-3564 mounting $ 00 recommended. 249. 4 Channel Wireless Receiver This receiver will accommodate up to four 2.4GHz cameras and will scan through or simply display the selected channel. Supplied with 1m RCA Video lead and mains plugpack • Dimensions: 155(W) x 110(L) x 50(H)mm SAVE • Suits all our 2.4GHz cameras $30 1199 Was $99.95 Cat. QC-3588 $ 95 69. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au 'Grabit' Damaged Screw Removal Tool This fantastic tool will easily remove screws with even the most badly stripped heads. It doesn’t even matter if they were slotted, Phillips, Torx, or some other tamper-proof screw. This tool WILL get it out. The extraction bit consists of a burnishing bit that prepares a tapered hole in the screw head. You turn the bit around, reverse the cordless drill direction and the extractor bites into the prepped hole with tremendous force. Works equally well on brass, steel, stainless screws, etc. The TD-2059 consists of two 1/4" hex drive bits that cover screws from #6 to #14 gauge. They come in a small plastic case with instructions. It's not cheap, but what it can do for you is priceless. Cat. TD-2059 $ 95 49. Pin Extractor Tools Take the frustration out of removing Molex connector pins with these time saving tools. Male pin extractor Cat. TH-1730 Both Types (ea) $ 95 Female pin extractor Cat. TH-1732 14. Missile Launch Style Toggle Switch Cover Carbon fibre in appearance this heavy duty protective cover fits Cat. ST-0584 any toggle switch with a $ 95 12mm mounting hole. 5. Test and Measurement Pro-Style Pen DMM This precision instrument is made using modern double moulding techniques to make it tough enough to be used every day and includes nifty features like having a spot to put the probe guard when in use. 7 functions in the one unit. Cat. QM-1498 $ 95 Cat III 600V safety design. Designed with the DIY car enthusiast it mind, this unit has standard meter functions and features a 3.5 digit LCD with automatic zero adjustment, low battery warning and auto power off. Includes dwell angle and RPM (x1, x10) for 4, 5, 6 and 8 cylinder engines. • Probes, holster and Cat. QM-1440 battery included $ 95 SAVE Was $49.95 $10 39. Analogue Multimeter 29. Use air, gravity and energy to perform experiments and model famous inventions. With over 10 projects, create simple machines to become an expert in the field of aerodynamics. • Suitable for ages 7yrs+ Cat. KJ-8810 While stocks last High Quality 5.5" Electrical Shears 19. These shears have insulated handles and offer impressive cutting ability with finely serrated blades. Great for cutting insulation, heatshrink, Cat. TH-1758 spaghetti and light duty $ 95 hook-up wire. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 SAVE $5 34. All Kits (ea) $ 95 59. Piezo Ignition Butane Gas Torch Precision Soldering This tool is manufactured from quality carbon steel and fitted with hardened and tempered jaws. Suitable for crimping insulated terminals from 0.5mm≤ to 6.0mm≤ in size. • Overall length is 220mm Cat. TH-1829 Was $39.95 $ 95 Inventions in Flight This book covers everything from atomic structure, to DC and AC theory, semiconductors, integrated circuits and communications. Each chapter has a quiz at the end so you can test your knowledge of each subject. • Softcover. 699 pages, 232 x 190mm Cat. BM-7108 $ 95 46W Heavy Duty Ratchet Crimping Tool INTERNET> www.jaycar.com.au 9. 12. Teach Yourself Electricity and Electronics 4th Ed. Tools 19. Enjoy and learn about dynamics and motion. This kit contains many amazing and exciting activities relating to gravity, mechanics and different forms of energy. • Suitable for ages 8yrs+ Cat. KJ-8814 8. 30A Cat. SY-4077 $ 95 39. The pistol grip on this driver gives you maximum control and allows your fingers to fall naturally on the forward/reverse control switch. It has an LED lamp, magnetic bit holder and a battery level indicator. Mains charger and 4 bits included. • Bit holder size: 6.35mm Cat. TD-2498 • Belt pouch now available $ 95 TD-2499 $5.95 Inventions in Vehicles 15A Cat. SY-4076 $ 95 Cat. TS-1660 $ 95 Cordless 4.8V Screwdriver Experiment with waterpower and recreate the history of how boats are made. Learn about floatation, buoyancy stability and speed with 13 fun and exciting projects. • Suitable for ages 8yrs+ Cat. KJ-8812 Designed for automotive applications, these quality relays have an integrated blade fuse and metal mounting bracket. • Fuse supplied • Two types available Ideal for brazing, silver soldering, jewellery work, heatshrinking, and a whole lot more. It has an 1300°C adjustable flame and includes a stand. • Dimensions 150 (H), base 69 x 69mm • 150g Butane Gas NA-1020 $4.95 A well made meter for those who prefer the analogue meter movement to the digital. It has several 'digital' features, like a 10 amp DC current measuring capability, continuity buzzer and safety shrouded probes. See website or Cat. QM-1020 catalogue for full $ 95 features. Kits Projects for Kids Inventions in Boats 39. Dwell Tacho DMM SPST Automotive Fused Relays Soldering Iron This soldering iron offers exceptional heat recovery. With its high insulation and low current leakage, soldering of precision flat ICs and CMOS is a breeze. 13W Pencil Cat. TS-1430 $ 95 59. Leightweight Soldering This is the most delicate direct mains iron we have ever seen. It features a comfortable non-slip rubber finger grip and balances Cat. TS-1446 $ 95 perfectly when held. 39. Anti-Static Temperature Controlled Soldering Station This soldering station is a precision, Japanese manufactured instrument SAVE with excellent $30 temperature stability and anti-static characteristics. It has a digital temperature adjustment from 200 to 480°C at 65W and a lightweight soldering pencil. See website or catalogue Cat. TS-1440 for full specifications. $ 00 Was $229 199. 7 Speedo Corrector MkII Refer: Silicon Chip December 2006 When you modify your gearbox or change to a large circumference tyre, it may result in an inaccurate speedometer. This kit alters the speedometer signal up or down from 0% to 99% of the original signal. With this improved model, the input setup selection can be automatically selected and it also features an input LED indicator. Kit supplied with PCB with overlay and all electronic components. Cat. KC-5435 $ 95 The Short Circuits Learning System Magnetic Cartridge Preamp Kit Refer: Silicon Chip August 2006 This kit is used to amplify the 3-4mV signals from a phono cartridge to line level, so you can use your turntable with the CD or tuner inputs on your Hi-Fi amplifier. The design is suitable for 12" LPs, and also allows for RIAA equalisation of all the really old 78s. Kit includes PCB with overlay and all electronic components. Note: Only suitable for moving-magnet cartridges. • Power: 12VAC • Recommended magnetic cartridge AM-4020 $45.00 49. The Short Circuits learning system is a great way to learn electronics. It is fun, informative, and you build great projects along the way. Here are just two examples of projects in the Short Circuits series. Wind and Rain SFX This kit simulates the sound of falling rain or howling wind. Must be connected to an amplifier (use amplifier project 11 or 13). Kit includes PCB and electronic components. Features in Short Circuits #3. • BJ-8505 $19.95 Cat. KJ-8088 $ 95 16. Sound Level Meter Make your own fancy volume level display you see on DJ mixing decks where the columns of light dance up and down with the music. Connect it to the output of your CD, tape player or radio. Cat. KJ-8212 Features in Short Circuits #2. $ 95 • BJ-8502 $14.25 Cat. KC-5433 $ 95 39. 12. YOUR LOCAL JAYCAR STORE The Tempmaster Freecall Orders: Ph 1800 022 888 NEW SOUTH WALES Albury Ph (02) 6021 6788 Alexandria Ph (02) 9699 4699 Bankstown Ph (02) 9709 2822 Blacktown Ph (02) 9678 9669 Bondi Junction Ph (02) 9369 3899 Brookvale Ph (02) 9905 4130 Campbelltown Ph (02) 4620 7155 Erina Ph (02) 4365 3433 Hornsby Ph (02) 9476 6221 Newcastle Ph (02) 4965 3799 Parramatta Ph (02) 9683 3377 Penrith Ph (02) 4721 8337 Silverwater Ph (02) 9741 8557 St. Leonards Ph (02) 9439 4799 Sydney City Ph (02) 9267 1614 Taren Point Ph (02) 9531 7033 Tweed Heads Ph (07) 5524 6566 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 Sunshine Ph (03) 9310 8066 QUEENSLAND Aspley Ph (07) 3863 0099 Mermaid Beach Ph (07) 5526 6722 Townsville Ph (07) 4772 5022 Underwood Ph (07) 3841 4888 Woolloongabba Ph (07) 3393 0777 AUSTRALIAN CAPITAL TERRITORY Belconnen Ph (02) 6253 5700 Fyshwick 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 Maddington Ph (08) 9493 4300 Northbridge Ph (08) 9328 8252 NORTHERN TERRITORY Darwin Ph (08) 8948 4043 NEW ZEALAND Christchurch Ph (03) 379 1662 Dunedin Ph (03) 471 7934 Glenfield Ph (09) 444 4628 Hamilton Ph (07) 846 0177 Manukau Ph (09) 263 6241 Newmarket Ph (09) 377 6421 Wellington Ph (04) 801 9005 Freecall Orders Ph 0800 452 9227 8 Refer: Silicon Chip June 2005 This project turns a regular fridge or freezer into a wine cooler by accurately controlling the temperature to make it suitable for wine storage. A much cheaper option than commercial units. Kit supplied with PCB, case, mains plug and all electronic components. Battery Zapper Kit Mk II Cat. KC-5413 $ 95 39. IR Remote Extender MKII Kit Refer: Silicon Chip October 2006 Operate your DVD player Improved or digital decoder using Model! its remote control from another room. It picks up the signal from the remote control and sends it via a 2-wire cable to an infrared LED located close to the device. This improved model features fast data transfer, capable of transmitting Foxtel digital remote control signals using the Pace 400 series decoder. Kit supplied with case, screen printed front panel, PCB with overlay Cat. KC-5432 and all electronic components. $ 95 • Requires 9 VDC power and 2-wire cable 24. Improved Ref: Silicon Chip May 2006 Model! Like its predecessor this kit attacks a common cause of failure in wet lead acid cell batteries: sulphation. The circuit produces short bursts of high level energy to reverse the damaging sulphation effect. The improved unit features a battery health checker with LED indicator, new circuit protection against badly sulphated batteries, test points for a DMM and connection for a battery charger. Kit includes machined case with screen printed lid, circuit board, alligator clips and all electric components. Cat. KC-5427 Suitable for 6, 12 and 24V batteries $ 95 • Powered by the battery itself 99. Galactic Voice Kit Refer: Silicon Chip September 2006 Be the envy of everyone at the next Interplanetary Conference for Evil Beings with this galactic voice simulator kit. Effect and depth controls allow you to vary the effect to simulate everything from the metallically-challenged C-3PO, to the hysterical ranting of Daleks hellbent on exterminating anything not nailed down. The kit includes PCB with overlay, enclosure, speaker and all components. Cat. KC-5431 $ 95 44. HIGH PERFORMANCE ELECTRONIC PROJECTS FOR CARS BOOK There are 16 projects in total, ranging from devices for remapping fuel curves, to nitrous fuel mixture controllers, and more! The book includes all instructions, component lists, colour pictures, Cat. BS-5080 $ 80 and circuit layouts. There are also chapters on engine management, advanced systems and DIY modifications. 150 pages! 19. Frequency Switch This great module can be adapted to suit a range of different applications. Configure it to trigger water spray cooling on deceleration, shift light activation, adjustable aerodynamics based on speed, intake manifold switching and much more. Cat. KC-5378 Kit supplied with PCB, and all $ 95 electronic components. 35. PRICES VALID TO 31/01/07 High Range Adjustable Temperature Switch with LCD It can be set anywhere up to 1200°C, so it's extremely versatile. The relay can be used to trigger an extra thermo fan on an intercooler or mount a sensor near your turbo manifold and trigger water spray cooling or a simple buzzer to warn of high temperature. Easily dash mounted the LCD displays the temperature constantly. Cat. KC-5376 $ 95 69. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au SILICON CHIP Order Form/Tax Invoice Silicon Chip Publications Pty Ltd ABN 49 003 205 490 www.siliconchip.com.au PRICE GUIDE: SUBSCRIPTIONS YOUR DETAILS (Note: all subscription prices include P&P). (Aust. prices include GST) Your Name________________________________________________________ (PLEASE PRINT) Organisation (if applicable)___________________________________________ Please state month to start. 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SUBSCRIBERS QUALIFY FOR 10% DISCOUNT ON ALL SILICON CHIP PRODUCTS* * except subscriptions/renewals Qty Item Price Item Description Subscribe to SILICON CHIP on-line at: www.siliconchip.com.au Both printed and on-line versions available Total TO PLACE YOUR ORDER siliconchip.com.au P&P if extra Total Price BUY MOR 10 OR ISSU E BACK ES A 1 0 & G ET DISC % OUN T $A Phone (02) 9939 3295 9am-5pm Mon-Fri Please have your credit card details ready OR Fax this form to (02) 9939 2648 with your credit card details 24 hours 7 days a week OR Mail this form, with your cheque/money order, to: Silicon Chip Publications Pty Ltd, PO Box 139, Collaroy, NSW, January2097 2007  57 Australia 01-07 A Remote Telltale for Garage Doors If you have a perfect memory you won’t need this. But the rest of us could find it very handy! It lets you know if you’ve left the garage door open without stumbling out in the dark or the pouring rain . . . By JIM ROWE 58  Silicon Chip siliconchip.com.au siliconchip.com.au D ID YOU REMEMBER to shut the garage door when you got home? If you’re not sure, you might well go out in the morning to discover that your car, portable barbeque and mower have all been nicked. Perhaps you’d better go out and check now, just to make sure... What’s that – you don’t have to worry, because you have an electrically operated door? Fair enough, but you still have to press the remote or inside-the-house button to actually shut the door. Or maybe you did close it earlier and now you’ve just pressed the remote button to close it . . . and opened it? I won’t flog this any more, because I’m sure you get the idea. If you cannot see the garage door, it’s all too easy to either forget to close the door, or forget whether you did or not. That’s why we’ve come up with this project: a low-cost and easy-to-build remote sensing system. Based on of a pair of compact UHF transmitter and receiver units, the transmitter continuously monitors the status of your garage door via a pair of microswitches. Whenever that status changes (because you open or shut the door), it sends a short data signal back to the receiver unit, which uses these signals to update its LED door status indicators. This can be placed in any convenient position – where you can view it and see at a glance whether the garage door is fully open, fully shut or somewhere in between. Nifty, eh? Both units fit inside standard lowcost UB3 jiffy boxes and make use of very low-cost UHF data transmitter and receiver modules. You can build the complete ‘telltale’ system very easily and at low cost. By the way, the system would also be suitable for remote monitoring of other things beside garage doors. You could use it for monitoring security gates and doors, fire shutters and doors and so on – anything with an “open” and “shut” state. How it works To save you the near-impossible job of building and aligning transmitters and receivers (at least, not without some pretty specialised test gear and knowledge), we’ve based the system on a pair of UHF (433MHz) data transmitter and receiver modules which are sold by Oatley Electronics in kit form, with the catalog number K190. The four-channel modules include security encoding and decoding and the transmit and receive subcircuits are preset to frequency, so there’s no need for setup or alignment. The transmitter module uses an SM5162 security encoder chip, configured to provide four data inputs and eight Tri-state encoding inputs – so it can be set to any of 6561 different security codes. The receiver module uses a matching SM5172 decoder chip, again configured for four data outputs and eight Tri-state encoding inputs, so it can be set up to respond only to signals with whatever security code you have set on the transmitter. As a result the two modules provide a high degree of security and protection against false indications due to interference from other 433MHz signals. Another nice feature of the K190 transmitter module is the fact that it includes a simple circuit which only activates its transmitter circuitry when one of its data input lines is pulled ‘high’. We make good use of this feature. The circuit of the complete transmitter unit is shown in Fig.1, where the transmitter module is shown at centre right. The module’s power supply input +V is connected directly to the +9V line from the battery, so like the rest of the circuit it’s in ‘standby’ mode The inset shows one microswitch, mounted at the garage door “open” position. We had a fortunate bracket on the door on which to screw our microswitch actuating lever – a small piece of blank PC board. This has a little bit of spring and give to ensure that it makes good contact with the microswitch button. siliconchip.com.au January 2007  59 100k CON1 100nF 22k 100nF 13 NC 14 IC1d 100nF 9V BATTERY 470 µF 16V 11 12 K NO S1 9 100k UPPER LIMIT MICROSWITCH 22k 1M IC1c 8 14 3 IC3a IC1: 4011B 100nF 1 D1 10 A 1 2 470nF IC3: 4093B 3 IC1a +V D 2 K 5 D1–D4: 1N4148 K 6 A 1M 4 IC1b IC3d 7 11 7 LOWER LIMIT MICROSWITCH CON2 NC 100k 100nF A 13 13 B A 12 100nF 22k C D2 OATLEY K190 ANT UHF TX MODULE GND 470nF 10 µF 14 IC2d 11 12 S2 K 9 NO 100k 22k 1M IC2c 10 IC3b 8 4 A 5 6 IC2: 4011B 100nF 6 IC2b D3 470nF 4 5 SC  2007 GARAGE DOOR TELLTALE TRANSMITTER all the time. The total current drain is only about 100mA in this mode, so the battery should last for its full normal ‘shelf life’. Each of the transmitter module’s A-D data inputs is connected to the output of one of four identical pulseforming one-shot circuits. Each one-shot consists of a pair of cross-connected 4011B CMOS NAND gates forming a simple set/reset flipflop, set whenever a negative-going pulse is applied to its input via the 100nF capacitor. About 600ms after being set in this way, it is reset again 60  Silicon Chip K 2 1 1M IC2a 7 3 IC3c 10 D4 A 8 9 470nF automatically by means of an RC timing circuit coupled to a 4093B gate configured as a Schmitt inverter. The input of each one-shot is connected via a 100nF capacitor to a fixed contact of one of the two door-sensing microswitches, S1 and S2. The input of the ‘D’ one-shot is connected to the normally closed (NC) contact of microswitch S1, while the input of the ‘C’ one-shot is connected to the normally open (NO) contact of the same switch. The ‘A’ and ‘B’ one-shots are similarly connected to S2. The COM contacts of both S1 and Fig.1: the transmitter monitors the status (open or closed) of two microswitches which are mounted at the top and bottom travel of the garage door. The transmitter is based on a prebuilt module. S2 are connected to circuit ground, so that either the NC or the NO contacts are grounded depending on whether the switch is operated or not. The idea of these four one-shot circuits is that whenever either switch S1 or S2 is operated, a 600ms long pulse is generated by one of the one-shots A, B, C or D. This is fed to the transmitter module, so that it springs to life and sends the corresponding coded signal. Thinking about it another way, a different code pulse is transmitted whenever the garage door moves into or out of the fully shut position, or siliconchip.com.au REG1 7809 +9V OUT IN GND 10 µF Vdd A OATLEY B ANT K190 UHF RX C MODULE 5 6 D RXD 8 GND 4 IC1b IC1c 1 100k 13 B 100nF C 12 Q1 PN100 E 6 12V DC – IN 7 4 10k B DOOR OPEN λ LED1 λ C Q3 PN100 680Ω A POWER K K λ LED3 1N4004 K E A LEDS 3 11 IC2c 10 K 8 1 IC1d IC2b K 680Ω A 10 9 IC1a 14 5 2 10k DOOR A SHUT LED2 IC1: 4001B IC2: 4011B 14 9 TP1 + A 100nF 680Ω +V K 470 µF 16V +5V 100nF D1 1N4004 IC2a 10k 3 2 B C A Q2 PN100 E PN100 C B E 12 13 IC2d 11 7 SC  2007 GARAGE DOOR TELLTALE RECEIVER 7809 IN OUT GND Fig.2: the receiver consists of a pre-built UHF receiver mounted on an Oatley module with some logic gates and flipflops to control the status LEDs. into or out of the fully open position. For example, when the door reaches the fully shut position, the NO contact of S2 is grounded and the ‘A’ one-shot is triggered, sending a 600ms pulse to the A input, telling it to transmit the ‘door shut’ code. But as soon as the door begins to open again, the NC contact of S2 now becomes grounded. This triggers the ‘B’ one-shot, sending a 600ms pulse to the B input and causing a ‘door opening’ code to be transmitted. Then when the door reaches the fully open position, the NO contact of S1 becomes grounded and this triggers one-shot ‘C’, causing a ‘door open’ code to be transmitted. And finally, when the door begins to leave the fully open position to close again, the NC contact of S1 is grounded, triggering one-shot ‘D’ and the transmission of a ‘door closing’ code. By the way, the transmitter current drain rises to about 10mA only when a code pulse is being transmitted. So the battery only needs to supply this current for about 600ms, when the garage door’s status changes. Most of the time the transmitter will be in ‘standby’ mode, drawing only 100mA. So that’s how the Telltale’s transsiliconchip.com.au mitter unit operates. Now let us look at the circuit of the receiver unit (Fig.2), to see how it responds to these four possible codes from the transmitter unit. Receiver operation The four outputs from the UHF receiver module are each fed through one gate of a 4001B quad NOR gate, IC1. The inverted pulses from these gates are then used to trigger a pair of set/reset flipflops, each formed by a pair of cross-connected gates of IC2, a 4011B quad NAND gate. As a result, when a ‘door shut’ code is received and a pulse appears at output A of the receiver module, this produces a negative-going pulse at pin 4 of IC1b, and the upper IC2b/IC2c flipflop is triggered into its set state. Pin 4 of IC2b switches high, which turns on transistor Q3. This allows current to flow through LED2 – the ‘door shut’ indicator. Now if the door starts to open and a ‘door opening’ code is received, a pulse appears at the B output of the receiver module. This is inverted by IC1c, applying a negative-going pulse to pin 8 of IC2c and triggering the IC2b/IC2c flipflop into its reset state. Pin 4 of IC2b switches low, turning off Q3 and also LED2. Nothing then happens until the door reaches the fully open position, and a ‘door open’ code is transmitted. This causes a pulse to appear at the C output of the receiver module. Gate IC1a inverts this pulse and uses it to trigger the IC2a/IC2d flipflop into its set state. So this time pin 3 of IC2a switches high, turning on transistor Q2 and LED1 – the ‘door open’ indicator. Then when the door starts to close again and a ‘door closing’ code is received, a pulse appears at the D output of the receiver. This is inverted by IC1d and applied to pin 13 of IC2d, the reset input of the lower flipflop. So this flipflop resets again, turning off Q2 and LED1. Summarising, the receiver unit responds to the codes sent by the transmitter by turning on LED2 only when the garage door reaches the fully shut position, and turns it off again as soon as the door begins to open. Similarly it turns on LED1 only when the door reaches the fully open position, turning it off again as soon as the door begins to shut. So LED2 glowing indicates that the door is shut, while LED1 glowing indicates that the door January 2007  61 ANTENNA ANTENNA D C B OATLEY K190 UHF TX MODULE +V GND V+ OATLEY K190 UHF RX MODULE A 470 µF +V – D2 + 4148 4148 1M 1M D4 GND RXD VDD TP1 470nF 470nF + 9V BAT 100nF 4148 1M D3 10k 4148 100k D1 470nF IC3 4093B 470nF 26011130 6002 © GND GND B A GND D C ANT 100nF IC1 4001B 1M 100nF 100nF 680Ω IC2 4011B IC1 4011B Q1 PN100 100nF 100nF IC2 4011B 680Ω 680Ω CN 100k CON2 MO C CN ON 100k 100k CON1 MO C 100nF 100nF 100nF 100k ON 10 µF 100nF 22k + NC COM NO NC COM NO FROM S1 FROM S2 POWER 10 µF + DOOR FULLY PN100 OPEN Q3 10k 10k Q2 22k 22k 16011130 6002 © 22k LED2 LED1 LED3 DOOR FULLY PN100 SHUT D1 1N4004 REG1 470 µF 7809 12V DC IN Fig.3: the transmitter PC board component overlay and matching photo alongside. Top of page is a side-on, close-up view of the transmitter module mounted on the PC board. is open. When neither LED is glowing, this indicates that the door must be somewhere in between the two extremes – neither fully open nor fully shut. We make sure that neither LED1 nor LED2 lights when power is first applied to the receiver unit by applying a ‘power on reset’ pulse to both flipflops. This pulse is generated by transistor Q1, the collector of which goes positive for a short time after power is applied (until its 100nF base capacitor charges via the 100kW resistor). The positive pulse at Q1’s collector is fed to the second input of IC1c and IC1d, causing a brief negative-going pulse to be applied to the reset input of the flipflops. There is a third LED in the receiver unit (LED3), which simply indicates that power is applied. So when only LED3 is glowing, you can be reassured that this is because the door is neither fully open nor fully shut. The status LEDs in the receiver 62  Silicon Chip operate from 9V DC, derived from an external 12V DC supply using REG1. The rest (Including the receiver module) runs from 5V DC, derived from the +9V line via an L4949 LDO (low drop out) regulator IC on the receiver module. This arrangement allows the receiver to be operated from either a 12V battery or almost any plugpack supply delivering between 11.5V and 15V DC. The total current drain is quite low – about 25mA when only LED3 is glowing, rising to 35mA when either LED2 or LED1 is glowing as well. Construction Both the transmitter and receiver are built onto 57 x 122mm PC boards and housed in standard UB3 utility boxes. The transmitter board is coded 03101071, while the receiver board is coded 03101072. All of the transmitter components, apart from the door sensing microswitches, either mount on the board or fit into the box with it, while all of the receiver components mount on that board. The only items to emerge from the transmitter unit box are an antenna wire at the top and the leads to the microswitches at the bottom. Similarly, the receiver unit has its antenna emerging from the top and the power supply lead from the bottom. The location and orientation of all components on both boards are shown in the overlay diagrams of Figs.3 & 4. The wiring of each is quite straightforward, so if you follow these diagrams carefully you shouldn’t strike any problems. We suggest that you assemble both of the Oatley K190 modules first, before fitting either of them to their Telltale boards. But before you even start assembling the K190 transmitter module, its board needs to be shortened by cutting off the end strip where indicated by a dashed line on the overlay. This removes an optional part of the board which is only needed when the module is fitted with its own four input pushbuttons. After cutting this part off, use a small file to smooth off any burrs. One of the ‘components’ to be fitted to the K190 transmitter module board is another even smaller board, about 15mm square, already wired with the SMD components used in the UHF transmitter circuitry. This smaller board mounts on the top of the transmitter module board, with its three connection leads going down through holes and soldered to pads on the underside. The antenna and ground leads, at the righthand end of the SMD board, are NOT cut off short after soldering but are left intact so they can be connected directly to the main Telltale transmitter board later on. The only lead which is cut short after soldering to the transmitter module board is the siliconchip.com.au ANTENNA B A GND D C GND V+ 26011130 6002 © OATLEY K190 UHF RX MODULE GND RXD VDD 10k 100k TP1 100nF IC1 4001B 100nF Q1 PN100 100nF 680Ω IC2 4011B 680Ω 680Ω 10k Q2 POWER 10 µF + DOOR FULLY PN100 OPEN Q3 10k LED2 LED1 LED3 DOOR FULLY PN100 SHUT D1 1N4004 REG1 470 µF 7809 12V DC IN Fig.4: here’s the receiver PC board overlay and photo, again with the kit receiver module shown in situ top right. supply/control lead, which is at the lefthand side. After the SMD board has been fitted, solder in the 18-pin DIL socket for the SM5162 encoder chip and also the other components: six resistors (mounted vertically on-end), a 22nF capacitor and a C8050 transistor. Then solder seven short (~10mm+) lengths of tinned copper wire (eg, resistor lead offcuts) to the pads provided at each end for off-board connections. There are five of these pads at one end for the transmit inputs A-D and a V+ connection and two pads at the other end for a ground and +9V connection. Each of these wires needs to be perpendicular to the module board surface. Next, pass a 10mm M3 machine screw down through each of the module’s four mounting holes (from the top) and then fit an M3 nut on each screw. Tighten these nuts securely, because they are used as spacers. Once they are tightened the transmitter module assembly can be mounted siliconchip.com.au on the Telltale transmitter unit board, by passing each of the module’s connection wires through its matching hole in the main board, with the four mounting screws through their larger holes. Once the module is sitting above the main board on its M3 nut spacers, turn the whole assembly over and fit another M3 nut on each screw to hold it firmly in place. Then you can solder all of the module’s connection wires to their pads on the main board and cut off the excess. With the transmitter module in place, the remaining components can be fitted quite easily. Fit the four wire links first, then the two PC board terminal pins for the battery snap leads and the two 3-way terminal blocks for the microswitch lead connections. These are followed by the resistors, the MKT and multilayer monolithic capacitors, the polarised electrolytic capacitors and the diodes. After this you can fit the three ICs, or their sockets if you’re using them. Then, cut a 173mm length of singlecore hookup wire for the antenna and solder one end of it to the rectangular pad near the top centre of the board. Your Telltale’s transmitter board should be complete and ready to fit into its box, once the box is drilled to accept it. Drilling details for both the transmitter and receiver boxes are shown in Fig.6. The board mounts inside the rear of the box via four 15mm M3 tapped spacers, using four 6mm countersunkhead screws to attach the spacers to the box rear and four round-head 6mm screws to attach the board to the spacers. Just make sure that you pass the antenna wire out through its hole in the top end of the box, before you lower the board assembly into place and fit the fastening screws. Once the board assembly is mounted inside the box, you can solder the ends of the battery snap leads to the terminal pins at upper left on the main board (the pins marked ‘9V BAT’). Make sure that you solder the black wire to the outermost (minus) pin and the red wire to the inner (plus) pin (the one nearer the 470nF capacitor). Then you can connect the ends of the 2-core shielded leads you’ll be using to connect microswitches S1 and S2 to their terminal blocks at the bottom of the transmitter board. The inner wires of each lead are connected to the end terminals on each block (NO and NC), while the shield braids connect to the centre (COM) terminals. The transmitter unit can now be completed by attaching the 9V battery to the snap connector. You’ll find that the battery fits inside the box sideways above IC1 and IC2, with the snap lead wires coiled up above IC3. We placed the battery in a very small plastic bag to preclude the possibility of shorts. The box lid can now be fitted with January 2007  63 Parts List – Garage Door Telltale Transmitter Unit 1 ABS Jiffy box, UB3 size (130 x 68 x 44mm) 1 PC board, 57 x 122mm, code 03101071 1 Oatley Electronics K190 UHF transmitter module kit 2 3-way terminal blocks, PC mounting (CON1, CON2) 2 PC pins, 1mm diameter 4 15mm M3 tapped spacers 4 6mm M3 coutersunk-head machine screws 4 6mm M3 round-head machine screws 4 10mm M3 round-head machine screws 8 M3 nuts 1 9V alkaline battery with snap lead 2 SPDT microswitches 2 lengths of shielded cable for microswitch leads, two conductors plus shield Semiconductors 2 4011B quad CMOS NAND gate (IC1,IC2) 1 4093B quad Schmitt NAND gate (IC3) 4 1N4148 diodes (D1,D2,D3,D4) Capacitors 1 470mF 16V PC electrolytic 1 10mF 16V PC electrolytic 4 470nF MKT metallised polyester 4 100nF MKT metallised polyester 3 100nF multilayer monolithic ceramic Resistors (0.25W 1%) 4 1MW 4 100kW 4 22kW its label, which can be photocopied from Fig.5 (or downloaded and printed out from www.siliconchip. com.au). You’ll need to cut four holes for the lid mounting screws. The final step is to fit the small plastic sealing bungs above each screw head (these also hide any oopses in cutting the label!). Receiver assembly The Telltale receiver is assembled in much the same way as the transmitter. As before, we suggest that you assemble the K190 receiver module first. This module again has a small pre64  Silicon Chip Receiver Unit 1 ABS Jiffy box, UB3 size (130 x 68 x 44mm) 1 PC board, 57 x 122mm, code 03101072 1 Oatley Electronics K190 UHF receiver module kit 1 2.5mm DC connector, PC mounting (CON1) 1 PC pin, 1mm diameter 4 25mm M3 tapped spacers 4 6mm M3 countersunk-head machine screws 5 6mm M3 round-head machine screws 4 10mm M3 round-head machine screws 9 M3 nuts Semiconductors 1 4001B quad CMOS NOR gate (IC1) 1 4011B quad CMOS NAND gate (IC2) 1 7809 9V positive regulator (REG1) 3 PN100 NPN transistors (Q1,Q2,Q3) 1 5mm red LED (LED1) 1 5mm orange/yellow LED (LED2) 1 5mm green LED (LED3) 1 1N4004 1A diode (D1) Capacitors 1 470mF 16V PC electrolytic 1 10mF 16V PC electrolytic 1 100nF MKT metallised polyester 2 100nF multilayer monolithic ceramic Resistors (0.25W 1%) 1 100kW 3 10kW 3 680W wired SMD sub-board, which in this case is elongated and mounts ‘on edge’ near the centre of the receiver module board. Its three main connections to the rest of the receiver module are made via the pins of a 3-way 90° SIL connector near one end. The receiver antenna wire does not pass down through the module board, however. You solder it directly to the SMD board’s terminal pad later. The SMD receiver board is mounted on the K190 module board simply by passing its three connection pins down through the matching board holes and then soldering them to the pads underneath. After soldering do not cut off the pins though, because again they will pass down through holes in the main board and be soldered to pads underneath. Of course before this can be done you should fit the rest of the receiver module components. Again, there are only a handful of these: an 18-pin DIL socket for the SM5172 decoder chip, an 8-pin DIL socket for the module’s L4949 voltage regulator, two resistors (which are mounted on end), two small electrolytic capacitors (watch their polarisation), a 22nF polyester capacitor and a LED (provided for ‘valid data received’ indication). Before mounting the completed K190 receiver module onto the Telltale’s receiver board, turn it over and again solder some short lengths of tinned copper wire or resistor lead offcuts to the module’s off-board connection pads. In this case there are five of these at the top of the module board for the A-D outputs and a ground connection, plus two more at the upper left of the module for the +9V supply input and another ground connection. (There are also the three pins from the SMD module, which pass through into the main board as well.) When these off-board wires have all been fitted to the K190 receiver module, it is again fitted with four 10mm-long M3 machine screws, passed through each of the corner mounting holes from the top. Then fit each screw with a single M3 nut as before, to act as the mounting spacers. After tightening the nuts you can then attach the receiver module Resistor Colour Codes o o o o o No. 4 5 4 3 3 Value 1MW 100kW 22kW 10kW 680W 4-Band Code (1%) brown black green brown brown black yellow brown red red orange brown brown black orange brown blue grey brown brown 5-Band Code (1%) brown black black yellow brown brown black black orange brown red red black red brown brown black black red brown blue grey black black brown siliconchip.com.au The receiver (left) mounts on the lid of the receiver box, while the transmitter (below) mounts on pillars inside the box. The transmitter battery is loose inside the box. It is unlikely to short to anything in this area of the box but is placed inside a tiny plastic bag, just in case. to the Telltale’s receiver board, again by passing all of its connection wires and pins down through their matching board holes – and the four mounting screws through their larger holes. Once the module is resting down on the spacer nuts you can then turn the board over and fit the four remaining M3 nuts to fasten it securely, followed by soldering the connection wires and pins to their board pads. With the receiver module fitted, you can fit the rest of the components on the Telltale’s receiver board. This is easiest if you fit them in the following order: first the single PC board terminal pin for TP1, then the single wire link (just below the K190 module), ANTENNA ANTENNA and then the 2.5mm concentric DC power connector at bottom centre. Next fit the seven resistors, the two multilayer monolithic capacitors and the MKT capacitor, the two polarised electrolytic capacitors, the 1N4004 power diode D1, the 7809 regulator REG1 (its tab is attached to the board using a 6mm M3 screw and nut) and the three PN100 transistors (Q1-Q3). Then fit the two ICs or their 14-pin sockets if you’re using them, followed by the three LEDs. All three LEDs are mounted vertically, with their leads soldered to the board pads so that the tops DOOR DOOR of their bodies are about POWER FULLY OPEN FULLY SHUT 30mm above the top of TRANSMITTER the board. RECEIVER To complete the reUPPER LOWER 9 – 12V ceiver board assembly, cut LIMIT LIMIT DC INPUT SWITCH SWITCH another 173mm length of + – NC COM NO NC COM NO solid core hook-up wire for the receiver’s antenna and carefully solder one one end to the antenna Fig.5: suggested front panels for the project. By the way, there is no significance in the fact connection pad on the top that the boxes we used are different colours – you can choose which ones you want! siliconchip.com.au SILICON CHIP SILICON CHIP OOR D GE TE A R GA REMO LE LTA L E T OOR D GE TE A R GA REMO LE LTA L E T January 2007  65 20 A A 18 UPPER END OF BOX UPPER END OF BOX B B BOX MOUNTING HOLE AS REQUIRED B 47 B 47 94 CL CL 18 47 47 18 D D D 19 B B 24.75 B B 24.75 24.75 HOLE SIZES: A: 3mm DIAMETER B: 3mm DIAMETER, COUNTERSUNK C: 8mm DIAMETER D: 5mm DIAMETER OUTER REAR OF BOX 49.5 ALL DIMENSIONS IN MILLIMETRES 24.75 OUTER SURFACE OF LID 49.5 18.5 C 32 5 16 TERMINAL BLOCK ACCESS SLOT LOWER END OF BOX CL TRANSMITTER UNIT 17 LOWER END OF BOX RECEIVER UNIT CL Fig.6: drilling details for both boxes. These are based on a standard UB3 (130 x 68 x 44mm) Zippy box. 66  Silicon Chip siliconchip.com.au 03101072 © 2007 + 03101071 © 2007 NO NC COM NO NC COM end of the SMD receiver sub-board. You’ll find this pad on the top end of the SMD board, down near the top surface of the K190 board. The receiver board fits to the inside lid of its box, attached via four 25mmlong M3 tapped spacers, fastened to the box lid using four 6mm-long countersunk-head M3 screws. The board assembly is then mounted on the spacers using four 6mm long round-head screws, after making sure that the three LEDs pass up through their matching clearance holes. To complete the Telltale receiver, the antenna wire is then passed out through the small hole in the top of the receiver box as the lid and board assembly are lowered into the box. Then the lid is fastened into the box using the four small self-tapping screws provided, and finally the dress bungs pushed in to seal the screw holes. If you wish to use the front panels you will need to cut or drill holes for the four lid screws and bungs in both boxes and also the three LEDs in the receiver box. LED bezels can hide any blemishes around hole edges. Trying it out Now that both the transmitter and receiver units have been completed, you’re almost ready to make sure they’re both working and ‘talking to each other’. Connect the two microswitches (S1 and S2) to the ends of the cables from the transmitter unit. Make sure that the NC terminals on the transmitter board connect through to the NC lugs on the microswitches; the NO and COM terminals likewise. If you followed the wiring instructions earlier, the COM terminals will be connected via the cable shield. Next, connect a 12V battery or some other source of 12V DC to the receiver unit using a suitable power lead terminated in a 2.5mm concentric plug (centre pin positive). The receiver’s power LED3 should light to indicate that the receiver is working but both of the other LEDs should remain off. Now place the transmitter unit a few metres away from the receiver and try pressing the actuator button on microswitch S1, holding it down. You should find that LED1 (the ‘Door Fully Open’ LED) on the receiver should begin glowing, and continue to glow while ever you keep holding the S1 button down. siliconchip.com.au Fig.7: same-size PC board artwork for the transmitter (left) and receiver. When you next let go of the S1 button and allow it to snap out, you should now find that LED1 on the receiver turns off again. Now try pressing in the actuator button on microswitch S2, and again hold it in. This time LED2 (the ‘Door Fully Shut’ LED) on the receiver should light, and stay that way until you release the S2 button again. Only then should it turn off. If your system behaves just as described, everything is working as it should and you’ll be ready for its installation. Installation There is very little involved in installing the Telltale transmitter and receiver. The transmitter unit is simply attached to the inside wall of your garage, near the door to be monitored and fairly high up if possible (for the best UHF transmission range). It’s very small and light in weight, so it can be attached to the wall using a single screw. Once the box is in place, you need to fit the two microswitches to the side frame of the door – so they can be actuated by either the door itself, or a small extension bracket you can screw to the door. S1 needs to be actuated when the door is in its fully open position, while S2 is actuated when it’s fully shut. The cables running from each switch back to the transmitter box will need to be attached to the wall securely so they are protected against accidents. Installing the receiver unit inside your house is even simpler. Here all you need to do is mount the receiver box on the wall in a convenient position, again fairly high up for the most favourable UHF reception. For the most reliable operation, if possible it should be within 10-15 metres of the transmitter unit and the antennas should be aligned in the same plane (eg, both vertical). Then all that’s needed is to provide it with its necessary 12V power, and you’re finished. Your Garage Door Remote Telltale should be fully installed SC and operating. January 2007  67 Australia has gone from a leading manufacturer of radios and components to almost exclusively importing electronics – usually displaying the ‘made in China’ label. With an upsurge of new technology like MP3, GPS, Bluetooth and much more, it’s a revelation to find an Australian company designs and manufacturers high-tech world-leading innovative radios, making an impact worldwide. by Kevin Poulter WiNRADiO ® An Australian Success Story 68  Silicon Chip siliconchip.com.au W iNRADiO receivers are no ordinary radios, as they link to computers for awesome performance. Why have few Australians heard of WiNRADiO? Because 95% of its products are sold overseas, to clients like the US and UK Defence Departments. Originally a small Melbourne-based start-up, WiNRADiO introduced its first product, an ISAbus based receiver WR-1000i back in 1995 at the Sydney PC show. The receiver won the show’s ‘Best New Hardware’ award. Featuring a frequency range of 150kHz to 1300MHz, the product was the world’s first commercially available wideband scanning receiver for the PC. Radio receivers and computers have kept a respectful distance apart until recently. The main reason for this was the electromagnetic ‘storm’ of noise emanating from computers, making PCs unfavorable to radio reception. There is also the dissimilar technologies and jargon. To a computer aficionado, a “megahertz” is the frequency the CPU runs at, not something you actually tune to. Engineers at WiNRADiO made the first successful attempt to marry radio and computer technologies with innovative concepts, resulting in international radio-related patents and trademarks. Significantly, they made the computer an essential component of a radio receiver, with their latest designs adapting the computer to cover almost half of the radio operation. This means much of the conventional receiver circuits normally accomplished with an array of components (such as intermediate frequency filters and demodulators) have been replaced with software running on an ordinary PC. With WiNRADiO receivers, all that’s needed is their “front end” USB box or a PCI-bus card, for almost any PC to be instantly transformed into a powerful VHF/UHF scanner or a shortwave receiver. It’s not just for Government services. Many enthusiasts or audiences like to listen in to shortwave and other bands. Shortwave is still the only mass-media capable of reaching the world without supporting infrastructure. Now, with the advent of digital DRM technology, shortwave is finding new markets and applications. siliconchip.com.au The WR-G313 Let’s look at their WR-G313 HF receiver, popular amongst serious radio users, such as major broadcasting corporations, defence establishments worldwide and amateur radio enthusiasts. The London-based “Word Radio TV Handbook” rates radio receivers annually and awarded the G313 a five star rating. The receiver comes in two forms: an internal PCI card (G313i), as shown at the top of this page or as an external USB box (G313e) – shown underneath. Their performance is identical – the only difference is the hardware interface. The external G313e unit is housed in a small (164 x 96 x 41 mm) case, while the internal model is based on a 3/4-length standard PCI bus card, ready to to plug in and use. The only hint that they are a radio receiver is an SMAtype connector marked “antenna”. On the USB model, remaining external features are simply the power and USB connectors, power switch and blue LED. Frequency range of the WR-G313 is 9kHz to 30MHz, optionally expandable to 180MHz. Plug-and-Play installation is simple and similar for both models: just connect the device, insert the supplied CD ROM, and let Windows guide you through the usual device driver installation process. On completion, a rather impressive control panel appears (shown next page). January 2007  69 The screen At first look, there’s quite a resemblance to conventional radio receivers, with the tuning dial “knob”, frequency display and signal strength meter. A closer look reveals even more bells and whistles – eg, Notch filter and Noise blanker, plus a number of unusual demodulation modes. These advanced features, such as the real-time spectrum display which shows the actual spectrum of the station you are tuned to, are not typically found on any conventional radio. Further, press one of the yellow triangle buttons beside the on/off switch and an additional “sweeping” spectrum analyser neatly slides out at the bottom: Computer technology enables even more interesting goodies, not seen on a receiver before. For example, pressing the Test button will reveal a comprehensive test facility, normally only found on expensive laboratory test instruments: 70  Silicon Chip The spectrum of the demodulated signal is displayed in real time, enabling measurement of the frequency error and modulation parameters of the received signal. Using a signal generator, with the receiver in the SINAD function, you can even measure its own sensitivity. Pressing the Study button on the main panel reveals some of the technology. Demodulation is performed entirely by software, using “Software Defined Radio” technology. Each demodulation mode, like AM, FM and SSB, is performed by applying different mathematical formulas on a digitised IF (intermediate frequency) signal. So the diode and capacitor, for decades used as an AM demodulator, are now replaced by a mathematical formula. This makes the demodulation much more accurate and consistent and not affected by component non-linearities, temperature dependency and aging. The WiNRADiO G313 receivers show the internal structures of these “virtual” demodulators and even allow exploring in detail what’s happening to the signal during the demodulation process (see the AM demodulator image). siliconchip.com.au Here’s a look inside the USB version of the G313. At left is the control section with its PIC microprocessor and AD DSP, while the RF section is shown above right. Left or right-clicking on the block structure diagrams allocates the left or right spectrum to the two respective spectrum analysers. There’s also a vector voltmeter at bottom left, to display the amplitude and phase differences between the two signals. With many conventional receiver functions taken over by the PC, what’s actually inside the box? Above is a look inside the USB-based G313e model. The control board includes an Analog Devices digital signal processor plus a PIC microcontroller running the receiver. The other side, shown above right, is even more interesting. The receiver RF circuitry is divided into several sections. On the left there’s the receiver’s front end, which connects to the antenna. The amplified and filtered RF signal feeds to the mixer and the first IF (intermediate frequency) stage at bottom centre. At top centre is the master oscillator, based on DDS (Direct Digital Synthesis) technology and at bottom right, the second mixer and IF stage. All this produces a 12kHz intermediate frequency output, which is further filtered and processed by the DSP and the host PC. The biggest achievement is running a radio near or even inside a PC – traditionally, a major source of electromagnetic interference. Surprisingly, there’s no trace of PC interference with WiNRADiO receivers but they are not about to reveal to all how this trade secret is achieved. 3.5GHz with an optional downconverter), with fast scans and highly useful scanning-related features like CTCSS and DCS squelch. Its likely that digital trunking decoders are also on their way. In addition to the basic receivers, WiNRADiO produces many software options, such as a number of signal processing and decoding applications – for example, a DRM decoder, which neatly “plugs” in place of the standard “virtual demodulator” window. VHF/UHF WiNRADiO also makes VHF/UHF scanners. The latest low-cost G305e model ranges from 9kHz to 1.8GHz (or even To support their equipment, the company manufactures a range of antennas and other accessories. For much more information, including a full price list, visit the WiNRADiO website: www.winradio.com.au Where from? WiNRADiO G305 is described as aVHF/UHF model – which of course it is – but it covers down to 9kHz! siliconchip.com.au On the WinRadio website you will also find all the other models and the peripherals and options (and there are plenty of those!) Of the models mentioned here, the WR-G313i sells for $1333.27 and the WR-G313e $1599.93, while the PCI version of the G305 is $733.27 and the USB version $866.60 (all prices are plus GST). SC January 2007  71 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/ “Degen” Synthesised HF Communications Receiver Review by Ross Tester Elsewhere in this issue we feature “WinRadio”: a very high performance, computer-based radio receiver. As that review was being written, this tiny communications receiver also arrived at SILICON CHIP. It’s very significantly cheaper, covers the complete 100kHz to 30MHz MF/HF band (with 88-108MHz broadcast band into the bargain) and offers a wide range of user controls. We thought it apposite to put this review in the same issue so readers can get make their own comparisons . . . 76  Silicon Chip siliconchip.com.au Unusually for a radio of this size, it sports a line-out socket and, more importantly, a fine tuning control to help resolve SSB signals. Having SSB capability brings it right into the amateur radio market – especially at the price. T he first thing that strikes you about the Degen DE1103 Communications Receiver is that it is too small! “How can something this size deliver on the promised performance . . .” As one who was brought up on the b-i-g communications receivers of yesteryear (an ancient Geloso, if I remember correctly!) then through a Heathkit or two and more recently on the ubiquitous FROGs, it does take a bit of getting your mind around the fact that something this size offers performance far and away better than those and features that weren’t even a glint in the designer’s eye. It’s taken the development of microprocessors – as we saw with WinRadio – to get this sort of performance. So how big is it? Try 165 x 105 x 29mm - not much bigger than a typical personal AM/FM receiver. It weighs in at 300g plus batteries. Of course, there have been quite a few synthesised radios around this size in recent years – but this is one of very few (indeed if any!) we can recall which offers SSB (single sideband) reception. What’s so important about SSB? Ask any amateur operator – it puts more “punch power” into the signal by sacrificing parts which can be synthesised at the receiving end. Hence, more range. SSB on a standard AM receiver sounds like “Donald Duck” talk. Back to the Degen. It’s a dual conversion, PLL (phase-locked-loop) synthesised receiver offering continuous coverage from 100kHz through to 29.999MHz, plus the FM radio band of 88-108MHz (in stereo). And while the jog tuning control gives surprisingly good bandspread, you can also directly enter spot frequencies over the entire range. If that’s not good enough for you, there are also 255 memory channels (with memory scanning along with auto band scanning). It is obviously intended for the avid siliconchip.com.au There are sockets for a long wire antenna, headphones and a plug-pack adapator – and all are included in the box. The batteries included are rechargeable (NiMH) types which the external supply automatically charges.‑ shortwave listener as well as a more general market, as the band switch will progressively step it through the popular shortwave radio bands: 75m, 60m, 49m, 41m, 31m, 25m, 22m, 19m, 16m and 13m, along with the FM and AM broadcast bands. Various combinations of pushbuttons also make it perform other tricks, so a good read of the 28-page instruction manual is a must if you want to get maxium performance/ enjoyment from this radio. There’s a couple of controls included “because they could” such as a local/dx switch and a wide/narrow 2nd IF response switch for AM (wide band, <6kHz, has better tone reception than narrow band [<4kHz] but it is also noisier). It has the obligatory digital clock built in (with two alarms, no less) and a 1-99 minute sleep timer. Volume setting uses the same jog dial as the manual tuner and we must confess that is one feature we didn’t like. Perhaps it’s just a matter of getting used to it but we were continually moving off frequency when we meant to change the volume. And speaking of volume, there is plenty! The specs don’t mention the power output but we found that sub-20 (out of a maximum level of 64) was more than enough for normal listening. And as we mentioned earlier, using the jog dial in conjunction with the fine tuning control is more than good enough to resolve SSB signals. We didn’t try to measure sensitivity but deemed it more than adequate. It’s stated as <10uV on FM, <1mV/m on MW AM and <20uV on SW AM. And we didn’t have the opportunity to string the long-wire antenna to see just how much better it could be – but Avcomm’s Garry Cratt told us that he had done so and the performance was even better, as one would expect. OK, so what’s the verdict? We’ve already mentioned the one thing we didn’t like (again, that’s only a preference) but there’s a lot to like about the Degen DE1103. The one thing we haven’t mentioned is the price – and that was a real pleasant surprise. Avcomm are selling this, complete with NiMH batteries, plugpack, longwire antenna and earphones for just $159.00 (inc GST, plus freight). We’re trying to cast our minds back to other receivers in the genre without all the features of the Degen DE1103 and we can’t remember any that even approached this price! For more information call Avcomm on (02) 9939 4377 or visit their website: www.avcomm.com.au SC WHERE can you buy SILICON CHIP You can get your copy of SILICON CHIP every month from your newsagent: in most it’s on sale on the last Wednesday of the month prior to cover date. You can ask your newsagent to reserve your copy for you. If they do not have SILICON CHIP or it has run out, ask them to contact Network Distribution Company in your state. SILICON CHIP is also on sale in all stores . . . again, you can ask the store manager to reserve a copy for you. Or, to be sure that you never miss an issue and save money into the bargain, why not take out a subscription? The annual cost is just $89.50 within Australia or $96 (by airmail) to New Zealand. Subscribers also get further discounts on books, and other products we sell. January 2007  77 Here’s a cheap and simple battery charger which you can leave connected without risk of overcharge. Design by Branko Justic Words by Ross Tester “Intelligent” 12V Charger for SLA and Lead Acid Batteries 78  Silicon Chip siliconchip.com.au F ollowing our look at charging cordless tool batteries last month (Nicad and NiMH), we’re moving on to charging their big brothers: 12V Lead Acid and Sealed Lead Acid types. These are much less forgiving than Nicad and NiMH when it comes to letting them discharge – so if you have anything which uses a 12V battery (and who doesn’t?) this little project could get you out of a lot of trouble. It could even be used to keep your car battery always at maximum charge (which, incidentally, your car’s alternator/regulator normally does not!). Lead acid batteries of any persuasion do not like being left discharged. In fact, a brand new battery can have its life drastically shortened if not charged as soon as possible after discharge. I had to stop myself saying “as quickly as possible” just then – in battery parlance quickly means something completely different. And that can ruin a battery just as easily! As discussed last month, the trouble with most low-cost chargers is that they simply keep pushing charging current into the battery without any method of detecting the amount of charge. So it’s easy to overcharge (and cook) a battery. Perhaps worse, they don’t know how discharged the battery was before you started charging it. If you’ve only slightly flattened it you can, once again, overcharge it even if you do remember to turn it off. Unfortunately, we’ve all gotten used to our mobile phones where we tend to “plug ’em in and charge ’em” regardless of how much they’ve been used – because these days most phones (if not the chargers) have the “smarts” to stop batteries being overcharged. OK, so much for what we shouldn’t do. What should we do? There are two ways to charge a battery. The most unreliable method is to connect a charger for a certain period of time, dependent on the charging current. It’s unreliable for several reasons – one, (the unknown charge state) mentioned above; another is that human “forgettory” takes over and we leave the charger on far too long. Both result in overcharging. The second method is to monitor the voltage. You probably know that as a battery discharges, its voltage drops only slowly for a period, then as its charge diminishes it starts to drop rather rapidly, until it is exhausted (or “flat”), when the curve once again flattens out. Charging a battery is similar – in reverse. The voltage rises quite slowly at first, then much more quickly as it approaches full charge. It then flattens out as it is overcharged. If you were able to sit and graph the voltage for the whole charging period, you would be able to pick the point where you could say the battery was fully charged. But who wants to do that? Fortunately, we can nominate the point at which a battery is said to be fully charged. In a lead-acid battery, that’s generally assumed to be about 13.8V. So all we have to do is monitor the battery voltage and turn the charger off when the battery reaches that level. OK, that’s being a bit simplistic but in effect, that’s exactly what this charger does. It can be left connected permanently to the battery so that when the charge level drops – whether through use or by self-discharge – it will automatically switch itself back on again. siliconchip.com.au It’s a fully self-contained mains charger which will handle anything from small SLAs up to marine and diesel monsters. It might take a while to charge bigger batteries but can be left on indefinitely. It’s intended for mains operation (after all, it is mounted on a plugpack!) but with a little ingenuity, could also be used as the battery charger for a solar, wind or micro hydro installation. How it works The charger is based on an L4949 precision voltage reference and regulator, as was used in the Auxiliary Battery Controller last month. For more information on this chip, refer to last month’s article. It is powered by a 9V AC plugpack, connected to a simple half-wave voltage doubler consisting of 1000mF and 100mF capacitors and diodes D1 and D2. This gives January 2007  79 4.7k ~ ~ +29V DC (NO LOAD) E C K B + Q1 BD682 LEDS A Q2 C8050 B 8.2k 3 IC2b 1 4 2 E D1 1N5819 IC2a 4.7k 82k 8 100 µF 82k CHARGING LED1 D3 1N4148 5 K A IC2c 14 1k 10 6 11 4.7k A λ K SC B IC2: 4093B 100 µF* K 2007 E C +5V 82k 1000 µF* A E 8.2k C 9V AC INPUT 1 2 * HIGH RIPPLE, HIGH TEMPERATURE TYPES C B BD682 8 BD6 K D2 A 1N5819 100 µF C8050 9 12 TO BATTERY 2 7 13 CHARGED A LED2 IC1 L4949 8 λ 7 IC2d 82k 5 47 µF 22nF 18k K INTELLIGENT 12v BATTERY CHARGER 1N5819 1N4148 A A K – K Q1 switches charging current on when the battery voltage sensed by IC1 falls below a preset threshold. Once the battery is charged, it switches off again. This means that the battery will not be overcharged. an unloaded, pulsating DC voltage in the region of 29V. The two capacitors are special types, capable of handling the high ripple current of the voltage doubler and also have a higher-than-normal temperature rating, as they can run rather warm. The current this simple arrangement is capable of supplying is limited largely by the reactance of the 1000mF capacitor and the plugpack supply – it’s in the order of a couple of amperes. But remember that this is a half-wave supply so as it stands it has far too much ripple (hum) to use for anything but a battery charger! Now let’s turn our attention to IC1, the L4949. It’s used in a similar way to last month, detecting a voltage at pin 2 and switching a series of logic gates in IC2, a 4093 quad Schmitt NAND, via its output, pin 7. Once again, the chip’s internal 5V regulator is used to supply a stable voltage to the gates, which in this circuit are connected as inverters (both inputs connected together). The battery voltage is monitored at pin 2 of IC1. As the battery is drained and its voltage falls below IC1’s threshold, an internal transistor connected to the output (pin 7) is turned on, resulting in the output falling to logic level 0. This drives the inputs of paralleled gates IC2c and IC2d low. Their outputs then go high, forward biasing diode D3 and very quickly charging the 47mF capacitor at its cathode. IC2b’s inputs are then taken high, sending its output low. Because there is no drive for LED2, it stays extinguished. But IC2a’s inputs are now also low, sending its output high. LED1 does have drive and now lights, indicating the battery is being charged. At the same time, the NPN transistor Q2 is fully turned on, which in turn pulls the base of Darlington transistor Q1 low, turning it fully on. In this role Q1 is simply an on or off switch. When it is turned on, current can flow into the battery, which starts to charge. The voltage doubler is incapable of maintaining the (unloaded) peak voltage and it drops down to around 15V or so. Eventually, the battery charges and the voltage at IC1’s pin 2 exceeds the threshold voltage. The output (pin 7) is now pulled high by the 82kW resis- The plugpack has two plastic guards (see left) which need to be removed so that the PC board can sit flat. They break out easily with a pair of pliers, then a little judicious paring with a sharp knife removes any remnants. It’s easier to do with the screws out! 80  Silicon Chip siliconchip.com.au (1000mF) is a very tight fit between Q2 and the edge of the transformer, so you might have to juggle it a bit to get it in. Solder in Q2 at the same time as the 1000mF to make sure it fits properly. We decided to drill another hole in the PC board to get the best fit for this capacitor. All that’s left is Q1, the Darlington transistor. It mounts with its metal side up and its heatsink is then screwed down onto it. First, though, you’ll have to bend the three legs down 90° to go through the PC board. This is a bit tricky because you also have to make sure the hole through Q1 aligns with the hole in the PC board. When you think you have the bend right, temporarily secure Q1 to the PC board with the screw and nut before 9V AC IN Building it D1 100 µF + o 1000 µF + 5819 5819 105 82k 1k D3 4148 IC2 4093B 4.7k 4.7k D2 Q2 LED2 + soldering it in – that way, you can be sure it is in the right place and the solder joints won’t be stressed when you tighten the nut on permanently. Solder Q1 in, then fit the heatsink with the single nut and screw from the underside of the board. The heatsink, which is up off the PC board by the height of Q1, hides two resistors and partly obscures two more. Fitting to the transformer The PC board is designed to screw directly to the output terminals of the supplied plugpack transformer. It can also be used with another PC board screw terminal block to connect to a transformer without the screw terminals. Note that it must be a transformer (AC output), not a DC supply. We’ll assume that you are using the TO BATTERY UNDER CHARGE – Q1 V+ + C8050 (Q1 METAL SIDE UP) BD682 GND The same-size photo at left matches the component overlay diagram of the assembled board at right. The 1000mF capacitor (right top) is a rather tight fit! It and the other brown 100mF electro are both 105° types. o 4.7k IC1 L4949 LED1 82k 18k 22nF 100 µF 100 µF 105 8.2k 8.2k CHARGED CHARGING + siliconchip.com.au 47 µF © oatleyelectronics.com The first thing to do is a little surgery on the plugpack. It has a couple of guards moulded into the plastic around its screw terminals – but these are right in the way of where we want to mount the PC board! It’s quite easy to break these out with a pair of pliers. You may need to clean the area a little with a sharp knife because the PC board needs to sit flat. By the way, temporarily securing the PC board upside down onto the transformer makes it a handy little soldering holder! After checking the PC board for any defects, start assembly by soldering in the resistors and non-polarised capacitor. Use the resistor colour code table and/or a DMM to check their values – particularly the 82kW and 8.2kW (they’re easy to mix up!). Next to solder in are the two IC sockets, making sure the notches match the PC board screen overlay, along with the screw terminal connector. The three diodes and two LEDs are next – watch the polarity and note that the two 1N5819 diodes at the top of the PC board mount opposite to each other. Both LEDs can be mounted hard down on the PC board. The cathodes (shorter leads closest to the flat edge of the base of the LED) mount towards the bottom of the PC board. Now solder in the four smaller electrolytic capacitors, taking care with polarity. The largest electrolytic 240V – 9V AC PLUGPACK + tor to +5V. As the inputs to IC2c and IC2d are now high, their outputs are low, IC2b’s output is high and LED 2 lights, indicating that the battery is charged. With IC2a’s input high, its output must be low, therefore Q2 receives no forward bias and both it and Q1 turn off, shutting off the charging current to the battery. This doesn’t remove power from the monitoring circuit because it continues to be powered by the charged battery. We mentioned the 47mF capacitor at the junction of IC2a and IC2b before but not since. It, along with the 82kW resistor in parallel, form a short time delay. The 82kW resistor discharges the capacitor slowly, preventing the circuit from “hunting” back and forth, which it could do as the battery loads down the main supply voltage. 82k 82k K215 HEATSINK MOUNTS ABOVE RESISTORS ON TOP OF TRANSISTOR transformer included in the kit – with the screw terminals. After giving the assembled PC board a thorough check to make sure the components are in the right places, in the right polarity (where appropriate) and are soldered in properly, the board can be attached to the transformer. The photographs show this clearly. The two screw terminals are on the underside of the transformer. The PC board is attached to the transformer with the screws on the same side of the board as the copper tracks. (Mounting it the opposite way around, though possible and will not do any harm, will not allow the charger to fit into a wall-mounted power point because the components will be in the way). Undo the screws enough to slide the board in, copper side up, then January 2007  81 Parts List – 12V Battery Charger 1 PC board, 53 x 54mm, coded OE-K215 1 240V-9VAC/2.22A plugpack 1 mini finned heatsink 1 8-pin IC socket 1 14-pin IC socket 1 2-way screw terminal block, PC mounting 1 M3 x 10mm screw, nut & washer Semiconductors 1 L4949 5V regulator and voltage sensor IC (IC1) 1 4093 or 4011 quad NAND Schmitt trigger (IC2) 1 BD682 PNP Darlington transistor (Q1) 1 C8050 NPN transistor (Q2) 2 1N5819 Schottky diodes (D1, D2) 1 1N4148 signal diode (D3) 1 5mm red LED (LED1) 1 5mm green LED (LED2) Capacitors 1 1000mF 50V 105°C electrolytic (do not substitute) 1 100mF 50V 105°C electrolytic (do not substitute) 2 100mF 35V electrolytic 1 47mF 16V electrolytic 1 22nF polyester (code 22n or 223) Resistors (0.25W 5%) 4 82kW   1 18kW  2 8.2kW 3 4.7kW   1 1kW do them up tightly so that they grip the PC board and make contact with the tinned copper area. It’s as simple as that! If your PC board doesn’t sit flat, it’s probable that you have some remnants of the plastic guard ridges stopping it being screwed right down. This close-up photo of the edge of the PC board shows how the heatsink is bolted to the transistor (Q1) underneath, with some resistors also beneath the heatsink. Q1 lies flat on the PC board with its metal face upwards to make contact with the heatsink. Testing Without any battery connected, plug the charger into a power point and turn it on. The red “charging” LED should light. If it does, you can be reasonably confident everything else is OK. If you measure the voltage at the output connector, it should be somewhere around or above 25V DC. Now connect a length of polarised figure-8 cable to the output connectors and connect the other ends to a 12V battery – watch the polarity! A pair of alligator clips on the cable make this easy. The voltage at the output terminals will drop significantly, depending on the state of charge of the battery. With a known “good” but discharged battery (eg, one that hasn’t been sitting around discharged for months!) this voltage could be somewhere around 10-12V. As the battery charges, this voltage will rise up to a maximum of about 15V, at which stage the green LED will come on indicating that the battery is charged. The green LED flashes? We mentioned earlier that there is a time delay built into the circuit to prevent it hunting back and forth. This also has another effect: periodically, the red LED goes out and the green LED comes on. This is not indicating full charge – the green LED Resistor Colour Codes o o o o o No. 4 1 2 3 1 Value 82kW 18kW 8.2kW 4.7kW 1kW 82  Silicon Chip 4-Band Code (1%) grey red orange brown brown grey orange brown grey red red brown yellow purple red brown brown black red brown 5-Band Code (1%) grey red black red brown brown grey black red brown grey red black brown brown yellow purple black brown brown brown black black brown brown Here’s how the PC board mounts onto the transformer, after the plastic guards have been removed. It will work the other way up but the components will stop the plugpack fitting on a wall-mounted outlet. stays on constantly when the battery is charged. What happens is that the 82kW resistor discharges the 47mF capacitor, switching the charging off. But if the L4949 hasn’t registered a charged battery, the capacitor charges again, turning the charging back on. This happens continuously while the battery is charging. If you wish, the frequency at which this switching occurs can be decreased by increasing the 82kW resistor and/ or the 47mF capacitor. A value of 1MW and 100mF will increase the time to 100 seconds. It’s running hot! Several components in this project run quite warm, even hot, to the touch. The transformer, for example, can get quite warm (but it should never get uncomfortably hot). Q1 (on its heatsink) has to dissipate a fair amount so it can get too hot to touch. Indeed, if you are wanting to charge car batteries, the PC board-mounted heatsink is probably inadequate and should be replaced with a bigger unit. For small SLA batteries, it should be OK. Finally, the 1000mF and 100mF capacitors in the voltage doubler will run fairly warm – but they are 105°, high ripple types and are designed to handle the heat. SC Where from, how much? This project was designed by Oatley Electronics, who hold the copyright. A complete kits of parts, including the special 9V AC plugpack transformer, is available for $18.00 plus $7.00 pack & post within Australia (Cat K215). Contact Oatley Electronics, PO Box 89, Oatley NSW 2223, or via their website, www.oatleyelectronics.com siliconchip.com.au HIGH CURRENT RELAY INTERFACE KIT K236 HIGH VOLTAGE WARNING: As this kit involves a dangerous and potentially lethal high voltage, only persons experienced with high voltage wiring techniques should attempt its construction. This relay based interface kit can switch up to 20A at mains potential, whilst only drawing a few milliamperes from the logic source, such as a microprocessors, digital logic circuits, computers etc. It could be used in various applications such as industrial controls, motors, solenoids, consumer appliances, etc. The relay used is made by Omron model G7L-1A-P, listed contact rating of 30A. 20A 277VAC(GEN), 20A 120VAC(GEN), 1.5KW 120VAC(XT), 1.5HP 120VAC, 3HP 277VAC, SOLAR PANEL WITH BATTERY AND CHARGING SYSTEM NOT DRAWN TO SCALE This system uses 1 X SP10 10W solar panel, 1 X K008B solar regulator kit and 1 X PB6 Sealed lead acid battery. Ideal for remote locations for lighting, radio or TV etc. Simple to connect and simple to install. Locate the panel facing north in a position of maximum sun exposure. The K008B regulator then looks after the charging of the battery automatically, so it does not over charge. Normal price for this system $165.00. Buy all three together for just $140.00 For a mean 5 hour solar day the battery would receive a charge of 3.5AHr's from a 10W solar panel: Sufficient to power one of the lamps below for 42 hours or all 5 lamps for 8 hours! $22ea or r 3 fo $50 BATTERY K248 14V INVERTER WITH 5 MR16 14V/1W LED LAMPS This simple inverter kit is designed to power these 14V lamps from a 12V lighting transformer or 12V battery. Operating range from 8V - 15V, 3mA <at> 12V quiescent, 340mA with 5 lamps. Delivers a constant voltage to the lamps. The kit includes PCB, all onboard components inc, pre-wound inductors. This package is designed to K243 HIGH POWER REVERSIBLE DC MOTOR be used with the above solar system. It can also be SPEED CONTROLLER KIT This kit is suitable for 10V to 30V motors. At 24V it can be used with our K237 low voltage cutout kit to protect used to power our 500W motors, up to 1KW when batteries from over discharging. K248 $49 additional MOSFETs are added (extra MOSFETs $10). The kit can be used with a single potentiometer or a 12mS R/C pulse. Kit inc. PCB & all on board parts. K243 $36 TV-10 120VAC, 20A 240V~cosf1, 20A 240V~cosf0.4, 20A 120V~cosf0.4. NEW DOG SILENCER KIT A new improved high power swept ultrasonic generator kit. It distracts dogs from their "Barking Loop" behaviour. Each time the dog barks press the onboard pushbutton or optional remote transmitter button to distract the dog from their "Barking Loop" behaviour. The output frequency and sweep rate are adjustable. Unlike previous versions the transformers are fully pre-wound and there is no coil winding to be done. Kit includes PCB, two tweeters and all onboard components. KIT: (K232) $33. Remote UHF trigger: (K232O) Brand new in original packaging. These temperature $23, Plugpack: (PP15) $10 controllers are self-operating, requiring no operating power. Temperature range 5 to 30°C. This device simply opens and closes a switch at the pre-set temperature. Would make a great controller for home brew or turn that old fridge into a wine cooler. Dimensions: 128 (W) x 73mm (H) x 55 (D) mm. Weight: 0.25kg. ZC0607:$24 DPM1 3 1/2 LCD PANEL METER: Check out our website fo more industrial switch gear etc. ZC0607 MECHANICAL AMBIENT TEMPERATURE CONTROLLER USED 100~240VAC-12V<at>2.5A POWER SUPPLY These switch mode power supplies are used but in good condition. They require a common IEC mains lead, we will supply the IEC lead for an additional $1. Measures 120mm X 60mm X 35mm. Power supply (DELTA1) $10 360deg. hemisphere detection, 360deg. 8M adjustable time & light, mains PIR SENSOR (DANGER) or 12V oper. 12V relay contacts O/P. Circuit K247 diagram inc. Sensor dim. dome 46dia. X 31mm(H), (91mm $12.50 overall). Can be setup to be impossible to approach without triggering. NEW AUDIO/VIDEO TRANSMITTER / RECEIVER KIT: This kit (K229T and K229R) are designed to transmit and receive video & stereo audio and to be as small as practical. Includes PCB, modules & all on-board parts. An antenna such as our K198 2.4GHz TX / RX ANTENNA KIT will increase the range of the K229T. K229T $17 Model # PM128. 0.5" LCD, 3.5 Digit, easy bezel fixing method. Dim. 68mmX44mm.DPM1 $9 PANEL METER INTERFACE KIT: (CDLS) CENTRAL DOOR LOCK SYSTEM Complete central locking system for a 12V vehicle. Comes with one master and three slave actuators, a control box, wiring loom and all the necessary hardware. Weight approx. 1.1kgs. $22 (ACTU) CENTRAL LOCKING ACTUATORS These are the same as the slave actuators used in the above central locking system. $5ea. CLEARANCE $29 K229R VRM1 24 SECOND VOICE / SOUND RECORDER MODULE: This small pre-built module will record up to 24 seconds of sound at the push of a button, then play it back at the push of a second button. Requires 6VDC to operate. Measures 34mm X 22mm Comes with a 29mm speaker. Now just 3 modules for $10 Add on isolation PCB with shunt/voltage divider for different voltages & current. The kit measures up to 20A and 12V with a wide range of adjustment. It has a built-in DC to DC isolated power supply to power the DPM1 at a very economical 3-5mA. This low current helps to reduce the drain on solar systems etc. K212 PCB is the same size as the meter (DPM1) and is designed to solder to and stack on the back of the DPM1. Kit includes PCB and all on-board components. KIT PRICE: (K212) $9.00 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_JAN_07 Salvage It! BY JULIAN EDGAR The multi-purpose tape machine Old tape-based answering machines can now be picked up for next to nothing or perhaps you’ve got one stashed away in the cupboard. Here are few ideas to put it to use. Tape-based telephone answering machines are now available free where ever electrical junk is discarded. So what can you do with them? As described in the text, there are plenty of novel messaging applications. 84  Silicon Chip L OOK AT THESE PICTURES – seen one of these before? If you said, “Yeah, of course I have – it’s just an old telephone answering machine” then think again. What you have in front of you is really a multi-purpose tape machine – one that’s able to leap tall buildings, etc . . . Well, not quite but it’s certainly capable of forming the basis for some interesting “no-cost” projects. Want some examples? OK, you live on a main road where there’s a constant stream of charity collectors and fervent religious followers continually coming to your door. You’re not against giving to charities but you’d prefer to do it on your terms not theirs and your religious beliefs are already firmly held. Here’s where that old answering machine comes in – you can use it to get rid of them. Imagine this: you’re just settling down to build a brand new electronic kit and the doorbell rings. You just know it’s not anyone you want to talk to so you just press a button that’s linked to the answering machine. One press is all that’s needed and the message is clearly and loudly played to those door squatters: “Thank you but I am not interested in anything that you have to sell or collect. Please leave my property forthwith. This is a recording so don’t bother answering back. The guard dog will be automatically released in 30 seconds”! And if you want to really want to drive the message home, you can have a harangue lasting up to a minute! Ha! – that’ll show ’em. Well, you get the idea, although in practice you might want the message to be a bit more restrained than that. In short, anywhere that a recorded message is needed at the push of a button, this machine can be used for it. And if you’re thinking, “why use a siliconchip.com.au Introducing the new and exciting range of Hot Devil Soldering Irons and Gas Torches BONUS PACK 2 FOR 1 UNDER $36.00 R.R.P. The unit we used was the Shimasu F-7010. It was listed in the Dick Smith Electronics 1996-97 catalog for $59.95 but can now be picked up at garage sales, secondhand stores and the like for a dollar or two. We got ours from a municipal tip, so it cost nothing at all. tape machine in this day and age?”, just consider the available message length and the cost. First, the machine costs nothing (or almost nothing) because you already had it stashed away in a cupboard or you scrounged it. And second, some tape answering machines can run a 3-minute message! Our answering machine The unit we used was the Shimasu F-7010. It was listed in the Dick Smith Electronics 1996 catalog for $59.95 and can now be picked up at garage sales, secondhand stores and the like for a dollar or two. The unit shown here came from a municipal tip, so it cost nothing at all. Recording & playing a message After you’ve made sure that there’s a tape inside the machine and it’s powered up, follow these steps. To record the message, press the OGM (out-going message) button until the LED flashes. Record your message and release the button. To play what you have just recorded, simply momentarily press the OGM button – it really can’t get much easier than that. Temp to 1300 oC Supplied with Bonus Pocket Torch valued at $12.95 R.R.P. Model No. MT6000SB MICRO TORCH The smallest ever Butane Gas MicroTorch and Soldering Iron with Auto Ignition UNDER $25.00 R.R.P. GAS TRIGGER TORCH & SOLDERING IRON Rat It Before You Chuck It! Whenever you throw away an old TV (or VCR or washing machine or dishwasher or printer) do you always think that surely there must be some good salvageable components inside? Well, this column is for you! (And it’s also for people without a lot of dough.) Each month we’ll use bits and pieces sourced from discards, sometimes in mini-projects and other times as an ideas smorgasbord. And you can contribute as well. If you have a use for specific parts which can siliconchip.com.au easily be salvaged from goods commonly being thrown away, we’d love to hear from you. Perhaps you use the pressure switch from a washing machine to control a pump. Or maybe you have a use for the highquality bearings from VCR heads. Or perhaps you’ve found how the guts of a cassette player can be easily turned into a metal detector. (Well, we made the last one up but you get the idea . . .) If you have some practical ideas, write in and tell us! Model No. PT16TS o Soldering up to 400 C Torch to 1300 oC o Hot Blow to 500 C Anti-Flare Wind Resistant R.R.P. Free Standing Auto Ignition UNDER $59.00 Model No. HT882 For your nearest stockist visit: www.hotdevil.com.au or phone: (03) 9775 0713 January 2007  85 As this photo shows, accessing the Outgoing Message Record pushbutton wiring, the speaker and the microphone is easy. It’s then straightforward to turn the old answering machine into a voice-warning annunciator, a talking burglar alarm, or even a sound generator in a model train layout. Note: the above steps are for the Shimasu F-7010 answering machine. Other tape-based answering machines work in similar fashion. A few uses There are plenty of uses that can be made of a warning message tape. Some are fun and others more serious. Here’s three examples: (1) Model railway sounds – the big advantage over generic sound simulator chips is that you can actually record real train sounds! One example is the sound of “ding-dong” level crossing bells – you can record these (perhaps with another tape recorder) and then the sound will be as realistic as possible. On the layout, the tape machine can be triggered by a reed switch activated by a magnet in the approaching train. (2) Interior car alarm – how would you feel as a thief if the owner started warning you ominously? “Warning! Warning! This car is being stolen. GPS tracking has been enabled. Warning! Warning!” It’s easy to do if the tape machine is triggered by a momentary input. Feed this message through a cheap car audio amplifier and an external horn speaker and very few thieves would proceed! (3) Industrial warning – this could be used to explain an “idiot light”; eg, “Low oil pressure has been detected. Turn off the engine immediately. Damage will result if the engine keeps running. This is the low oil pressure alarm”. The modifications Very little needs to be done to the machine to modify it for its new role – in fact, maybe nothing at all. For most applications, where the machine will be triggered remotely, it’s a case of opening it up and then connecting a new momentary pushbutton switch (or reed switch or relay contacts) via flying leads in parallel with the “OGM” button. To improve the recorded sound, you may want to remove the microphone from the case and re-position it, so that your voice is recorded more clearly. The playback also benefits substantially from a larger, more efficient speaker. If you want to get really loud, there’s nothing stopping you adding an amplifier. The volume control on the side of the answering machine should be set to match the amplifier’s input level. Don’t forget that cleaning the tape head (use methylated spirits and a cotton bud) and using a new tape can also appreciably lift the sound quality. Finally, don’t skimp on the quality of the message. For example, in the case of a burglar alarm warning, there’s nothing to stop you adding police sirens and running foot-steps as background audio to the warning message. That’ll really scare ‘em! SC Issues Getting Dog-Eared? Keep your copies safe with these handy binders. REAL VALUE AT $13.95 PLUS P & P Available Aust, only. Price: $A13.95 plus $7 p&p per order (includes GST). Just fill in and mail the handy order form in this issue; or fax (02) 9939 2648; or call (02) 9939 3295 and quote your credit card number. 86  Silicon Chip siliconchip.com.au Have you been watching the 2006 Ashes Cricket series? If so, you are unlikely to have missed the TV advertising promotion of “Boonanza” and the “Battle of the Tashes”. The idea is that you purchase two figurines of David Boon and Ian Botham, set them up in front of your TV and they will then make comments during the televised cricket matches. So how do they do it? The technical story of By LEO SIMPSON siliconchip.com.au January 2007  87 T his must be one of the greatest marketing ploys of all time. You go and buy a couple of “slabs” of VB (Victoria Bitter beer for the uninitiated) and this gives you the codes you need to buy a pair of plastic figurines of popular ex-cricketers David Boon and Ian Botham. Set up in the room where you watch television, these will then make loud comments pertaining to cricket and VB. In other words, you pay money to buy a pair of dolls that will then advertise beer! There’s even a web-site (www.boonanza.com.au) to promote the promotion and newsgroups have sprung up to log Boony’s and Beefy’s (Botham’s) comments and remarks. Their remarks are apparently spontaneous and they do interact. For example, if Boony asks Beefy to “Throw me a VB”, Beefy answers, “Nah, you’ll only drop it”. We saw a press story on these figurines which indicated that the figurines were reacting to data signals sent during the TV broadcasts using a proprietary technique developed by US company Veil Interactive Technologies Inc. (www.veilinteractive.com) “Very interesting,” we thought – and we set out to find out more. Our first step was to contact the Nine network to see if they would give us the inside story on this technology – but we could not get any comment. So we did the logical thing: obtain a pair of figurines. But no, we didn’t get them from the local liquor shop – we already had enough VB! Instead, we purchased ours on eBay. Well there is more than one way to skin a cat so we thought we would observe the TV screen when ever Boony or Beefy was moved to make a comment. This would give the clues to the signal being used in the Veil Technology method and we could even use our 200MHz digital scope to analyse the recorded signal. The scope can display any line of a TV frame and so it should be an easy matter to recognise a data stream. Possibly we could even duplicate the signal and send it to Boony to get him to speak. In more detail, the “veil” in Veil Technolgy stands for “video encoded invisible light” and we thought that this might also be a useful clue as to how the data signal 88  Silicon Chip might be incorporated into the TV picture. So perhaps the signal is modulated straight into the picture and not in the blanking interval and is done in such a way that it is invisible to the normal viewer. After watching many hours of the second Ashes cricket match in Adelaide (all done in the interests of science, of course), we came to the conclusion that a “veil” was indeed being rapidly wiped across the whole screen at the beginning and end of each action replay in the match broadcast. These wipes are very rapid and consist of three of four diagonal white stripes of differing widths – presumably 100% peak video modulation and thus most readily picked up via any optical sensor within the figurines. Was this the method being used? What a great scheme! Presumably the Nine Network could send a different data stream each time there was an action replay and Boony and Beefy could then make comments as to whether someone was out, whether it was great bowling and so on. Well that was the theory but in practice Boony and Beefy never responded to these great cricket moments. In fact, their remarks never seemed to relate to the game or the picture on-screen. Furthermore, they Boony and Beefy. They talk to each other – but is there a TV trigger? seemed to make comments just as frequently if the TV was off! So what was going on? Was this a likely explanation for Veil Technology and was it not being used during the Adelaide Test? Or is something entirely different going on? It was time to take the screwdriver to these locquacious little loudmouths! And they didn’t protest one little bit. Upturning the base of the figurine reveals one small screw which retains the lid of the battery compartment which holds three AA cells. Another four screws retain the base of the green plastic pedestal. Inside is a small blue PC board measuring about 40 x 40mm and an 8W loudspeaker about 30mm in diameter. Components on top of the PC board include a button cell (presumably for memory backup when the AA cells are flat or being replaced), a watch crystal (at 32kHz?), two electrolytic capacitors, a momentary contact switch and what appears to be a 455kHz ceramic resonator (marked 455E). Significantly, there is what appears to be a 3-lead infrared receiver/decoder chip (similar to that used in our infrared Remote Control Extender project featured in the October 2006 issue) and a companion clear LED – presumably also an infrared emitter. These two infrared components “look out” through the dark infrared filter window on the side the base – so the figurines can talk with one another. On the other side of the PC board is a host of surface-mount components which evidently include a microcontroller, amplifier circuitry and so on. Also present is another momentary contact switch (used in production setup perhaps?). Incidentally, this board is quite different in component count to those used in Boony for the 2005 Ashes series. Some details of this previous Boony are to be found on a number of newsgroups. One other piece of evidence is that our Boony’s PC board was labelled “Ocean Unicorn Ver A Jul 11 06”. Ocean Unicorn, as far as we can ascertain, is a small Hong-Kong siliconchip.com.au The only way (at least that we can see in our Boony and Beefy figurines) for the two to communicate with the outside world is via a small infrared window moulded into their bases. This was further borne out when we disassembled both and found what was lurking behind those windows. . . It’s an infared receiver, with an infrared LED alongside, (seen here right in the front centre of the PC board). There’s no microphone here, so it’s not picking up audio signals, as has been suggested on various websites. (Incidentally, last season’s Boony did have a microphone). No great surprises on the underside of the PC board either! The black blobs hide the CPU and presumably some form of ROM, while other devices of interest have had their markings removed. You can also see the small 8W speaker up inside the base of the figurine in this shot. based electronics design house/manufacturer. So what are our conclusions? Based on the fact that the main sensor appears to be an infrared receiver/decoder, the figurines seem unlikely to be able to respond to any data embedded in the TV pictures being broadcast during cricket matches or at any other time. This seems borne out by the fact that the figurines never sounded at critical times and could just as easily sound when the TV was off. Nor do the instructions accompanying the figurines make any mention of them being placed near a TV set. So much for Veil Technology in this particular case. The remarks made by Boony and Beefy are probably in response to a time/date counter in the microcontroller – hence the particular date code on the PC board and the need for a backup battery which would be necessary to maintain time-keeping. So if you have been intrigued by the “Battle of the Tashes” and “Boonanza”, you probably should not spend too much more time wondering how it is done. However, you cannot help admiring what must be one of the greatest marketing ploys ever. Not that we were taken in by it for a minute. After all that, I am feeling pretty thirsty. I wonder if there is any cold VB left in the fridge? SC TAKE YOUR PIC Picaxe.com.au DISTRIBUTOR: MicroZed.com.au Developed for students, & professional performance makes PICAXE the most easy-to-use micro ever: PICAXE “programmer" is two resistors and a 4.5V battery! PHONE (02) 4351 0886 8.30-4.30 AEST Mon-Fri FAX (02) 4351 0889 24 Hours ALL PICAXE ITEMS ON OUR SHELVES! STOCKISTS siliconchip.com.au In AUSTRALIA: altronics.com.au (Retail and Mail Order) oatleyelectronics.com School Electronic Supplies In NEW ZEALAND sicom.co.nz surplustronics.co.nz (School orders only – John - 03 8802 0628) January 2007  89 PRODUCT SHOWCASE World’s fastest USB Oscilloscope from PICO Pico Technology has unveiled the PicoScope 5204, a dual-channel PC Oscilloscope with a bandwidth of 250MHz, a memory depth of 128 million samples and a real-time sampling rate of 1 GS/s. All other oscilloscopes in this price range force you to compromise on one of the three key specifications: sampling rate, bandwidth or memory depth. The PicoScope 5204 excels in all three of these areas, making it a no compromise oscilloscope at a price every engineer can afford. The PicoScope 5204 connects to the USB port of any Windows laptop or desktop PC and offers an array of highend oscilloscope features, including advanced triggering and an equivalenttime sampling mode that can boost the sampling rate to 20 GS/s for repetitive waveforms. Other advanced functions include a built-in 250 MHz spectrum analyser and a 12 bit, 125 MS/s arbitrary waveform generator. The PicoScope 5204 is supplied with PicoScope 6, the latest release of Pico’s oscilloscope software, which takes advantage of the power of a modern PC to offer high-end oscilloscope features with an easy-touse Windows interface. New features include a waveform buffer that automatically records the last 32 waveforms and a “probe manager” that includes support for custom probes such as current clamps and allows users to define their own probes, even those requiring nonlinear corrections. With its USB streaming capability at speeds of up to 6 MS/s, the oscilloscope is ideal for high-speed data acquisition, as it can record huge sequences of gap-free data limited only by the memory of the PC. Pico- Multi-channel UHF Radio Modem The Radiometrix TDH2 is a 9600 baud half-duplex multichannel OEM radio modem with a power output of 25mW. This product acts as an intermediate-level OEM radio modem which fits between a raw FM radio module and a highly-sophisticated OEM radio modem device. Taking care of the preamble, synchronisation, bit balancing and error checking stages of development to provide a transparent serial cable to an attached host, it is a 100% pin-compatible drop-in replacement for the company’s TDL2A. It can be used as an alternative to its predecessor in application areas where greater levels of radiated power are likely to be desired. The modem’s default operating frequency is set at 433.925MHz. The adjacent channel rejection is 60dB at ±320kHz. It has a transmit power of +14dBm (25mW), and a receive sensitivity of -105dBm (for 1% BER). It is capable of supporting up to five Contact: user-programmed RF Modules Pty Ltd wideband chan- PO Box 1957, Launceston Tas 7250 nels, with channel Tel: (03) 6331 6789 Fax: (03) 6331 1243 widths of 320kHz. Website: www.rfmodules.com.au 90  Silicon Chip Scope 6 can also display automated measurements that range from a simple multimeter style voltage readout to advanced statistical and monitoring functions. Contact: Emona Instruments Pty Ltd 86 Parramatta Rd Camperdown NSW 2050 Tel: (02) 9519 3933 Fax: (02) 9550 1378 Website: www.emona.com.au “MERLIN” Safe External Switchmode Power Supply Practical and Versatile Mini Broadcast Audio Mixer Broadcast Quality with Operational Features and Technical Performance identical to full sized Radio Station Mixing Panels Permanent Installation is not required, the “Merlin” is as easy as a Stereo System to “Set Up”,all connections via Plugs and Sockets The “Merlin” originally designed for Media Training use in High Schools and Colleges is a remarkably versatile Audio Mixer Applications: Media Training - Basic Audio Production - News Room Mixer - Outside Broadcasts - Radio Program Pre Recording On-Air Mixer in small Radio Stations - “Disco Mixer” The “Merlin” is an Affordable Professional Audio Product Buy one for your School, College, Community Radio Station, Ethnic Radio Broadcast Association or for yourself For Details and Price, please contact us at ELAN Phone 08 9277 3500 AUDIO Fax 08 9478 2266 2 Steel Court. South Guildford email sales<at>elan.com.au www.elan.com.au Western Australia 6055 siliconchip.com.au New Jaycar NSW store and new SA location Jaycar Electronics has opened its latest store at Machinery Drive, Tweed Heads South, N.S.W. The store is over 200 square metres and has ample off street customer parking right outside the door. Like other Jaycar stores there is a wide range of electronic products available including home, car and commercial alarms, audio and video accessories, a fantastic range of car audio include subwoofer and amps, electronic components, test and measurement equipment, tools, leads and cable. For the summer season there is an extensive range of camping and outdoor products including power inverters, solar panels, batteries and accessories. If you’re travelling these holidays make sure your home or office is secure with an easy to install and maintain digital video surveillance system or alarm. Jaycar stores are staffed by local electronics enthusiasts who understand their products and can provide excellent technical service and this new store in Tweed Heads is no different! In addition, this year Jaycar celebrates 25 years in retailing and has many great in-store promotions. Definitely worth a visit! Jaycar have also relocated their Clovelly Park, SA, store because staff found conditions a little too hot to handle . . . the new (temporary) store is located at 2/1156 South Road, just 39m down the road from the old (burnt out!) store. Contact: Jaycar Electronics PO Box 6424, Silverwater NSW 1811 Tel: (02) 9741 8555 Fax: (02) 9741 8500 Website: www.jaycar.com.au Tektronix appoints TekMark as Australian distributor TekMark Australia Pty Ltd has been appointed by Tektronix as the authorised Australian distributor for its general purpose instruments business. This partnership gives customers uninterrupted accessibility to latest technology and will enable Tektronix and TekMark Australia to address and satisfy the needs of mutual customers in Australia. The Tektronix range of products will be a key component of TekMark Australia’s portfolio of test & measurement solutions and includes oscilloscopes, logic analysers, real-time spectrum analysers, signal sources and video test equipment. The TekMark Group of companies offers advanced test, measurement and monitoring instruments as well as integrated best-practice solutions and services to support the growing needs of high-tech industries. siliconchip.com.au In the November issue we reported that RS Components Ltd was a finalist in the Elektra 06 Awards in Europe. As we went to press it was announced that the company had beaten strong competition from Datec Technologies, Farnell InOne, and Samsung to win the Environmental Award. The judges awarded the trophy to RS in recognition of the work the company has done in preparation for the RoHS directive, which came into effect in July of this year. As well as providing a host of services to help customers understand and meet with the legislation, the company also worked with over 700 suppliers to obtain product compliance information. Its range of services includes compliance seminars, an online Knowledge Centre (www.rsaustralia.com/rohs), and the Notify Me service, where customers are emailed with the compliance status of unconfirmed products. RS has also kept customers up-to-date by introducing product compliance flags throughout the online order process and the introduction of printable certificates of compliance. The award was presented to RS at the 2006 Elektra European Electronics Industry Awards, held in Munich. Contact: Contact: RS Components Pty Ltd TekMark Australia 302/18 Orion Rd, Lane Cove NSW 2066 Tel: (02) 9911 3888 Fax: (02) 9418 8485 Website: www.tekmark.net.au Central Coast Field Day: it’s only a month away! One of the “most-looked-forward-to” days on the amateur and technology calendar, the Central Coast Field Day, is on again at the Wyong Race Course on Sunday, February 18th. The Central Coast Field Day is Australia’s largest Amateur Radio exhibition, with plenty of new and used radio and communication equipment on offer. There are always bargains to be had at the flea market where, along with individuals trading their treasures, many suppliers unload excess stocks, samples and other goodies at prices you will never find in their retail stores. RS Components wins Environmental Award You can also view exhibits by amateur and communications clubs and groups with interests ranging from vintage radio through to satellite communications – and everything in between. Wyong Race Course is a one-hour drive north of Sydney (with a good train service too!) and gates open at 8.30am. If it’s anything like previous years, there will be a queue at the gate waiting to rush in and bag the best bargains! For more information (and possibly even late stall bookings?) contact the Central Coast Amateur Radio Club on (02) 4340 2500 or via their website, www.ccarc.org.au SC PO Box 6864, Wetherill Park NSW. 1851 Tel: 1300 656 636 Fax: (02) 9681 8614 Website: www.rsaustralia.com TOROIDAL POWER TRANSFORMERS Manufactured in Australia Comprehensive data available Harbuch Electronics Pty Ltd 9/40 Leighton Pl. HORNSBY 2077 Ph (02) 9476-5854 Fx (02) 9476-3231 January 2007  91 Vintage Radio By RODNEY CHAMPNESS, VK3UG The Philips RF5 Stereogram Now considered to be relics of a bygone era, stereo radiograms (or stereograms) were common during the 1960s. The Philips RF5 stereogram was typical of this new breed of entertainment systems. I T WASN’T UNTIL towards the end of the valve era that manufacturers finally introduced stereo audio equipment. This resulted in the development of the stereogram, which typically comprised an AM radio receiver, a stereo turntable and stereo power amplifier stages, all built into a stylish wooden cabinet. The Philips RF5 is typical of many stereo radiograms of the 1960s. As with other units, it featured an AM radio section with a standard converter stage and one stage of IF (intermediate fre- quency) amplification and detection. From there, the audio signal is split two ways and fed to identical power amplifier stages which in turn drive the left and right speakers to give the “stereo” effect. Of course, when radio signals are selected, the effect is actually 2-channel mono rather than true stereo. True stereo signals could only be derived by playing 33 RPM stereo microgroove records on the turntable. In most cases, the speakers were located at opposite ends of the cabi- net and so were quite close together. However, some units used a “normal” mono radiogram cabinet and put the second speaker system into a satellite speaker box. This meant that the second speaker could be moved further away for better stereo effect. Stereo LPs sparked tremendous interest when they were introduced. In fact, older readers will remember the demonstration records that were used to sell the stereo effect. Some even had a recording of a steam train, complete with whistle, thundering through the lounge-room from one side to the other. Another common demonstration effect was a recording of a game of table tennis, in which you could hear the ball being hit first in one speaker then in the other. We thought that such demonstrations were marvellous at the time. Now they seem old-fashioned and quaint The Philips RF5 stereogram featured an AM radio and an automatic turntable that could play 33, 45 & 78 RPM records. 92  Silicon Chip siliconchip.com.au in the face of modern 5.1 channel (or more) home-theatre systems with surround sound. Circuit details Let’s now take a look at the circuit for the Philips RF5 – see Fig.1. It used five valves in total, with two in the radio front-end – a 6AN7 converter and a 6N8 IF amplifier/detector. The stage based on the 6AN7 converts the received broadcast band signal to the IF (intermediate frequency) which is at 455kHz. This stage is a little unusual in that tuning is accomplished using an inductance tuner instead of the more usual variable capacitor system. The following 6N8 functions as a combined IF amplifier, detector and automatic gain control (AGC) system. From there, the signal is fed to a 2-section pushbutton-type switch which selects between “Radio” and “Gram” (or gramophone). A third pushbutton switch provides power On/Off selection. In the “Radio” position, both audio amplifiers have their inputs connected in parallel. By contrast, in the “Gram” position, the two amplifiers are connected to the respective left and right channel outputs from the pick-up cartridge. The amplifier stages are each capable of about 3.5W (RMS) output power. The two audio amplifier stages are identical and use two 6GW8 triode/ pentode valves – one for each channel. The volume control (R51 & R52) is dual-ganged and each section has a tapping which is connected to an RC network. This modifies the tone of the output according to the volume setting. Potentiometer R18 functions as the balance control, while dual-ganged potentiometer R30/R31 functions as the tone control. Note that each amplifier stage has an unbypassed cathode resistor on pin 7 of the output valve. This gives a small amount of negative feedback for that stage, with additional feedback for the whole amplifier taken from the speaker transformer and applied via C25, R25 & R13 in the right channel and C26, R24 & R14 in the left channel. It’s fair to say that the audio amplifiers in the Philips RF5 stereogram are a cut above the amplifiers used in the mantel receivers of the era. Apart from the two feedback loops, a decentlysiliconchip.com.au This view shows the Garrard record changer and its instruction manual. Not many manuals survive this long. The inbuilt microphone can be seen at the bottom left of the photograph. sized audio output transformer is used in each channel and the speakers are reasonably well baffled. If you have one of these units and a speaker or output transformer develops a fault, you may have trouble getting a replacement. The reason for this is that the speakers are highimpedance 800W types, rather than the more popular 15W units. Power supply The power supply is quite conventional and uses a 6V4 rectifier to provide a HT rail of around 255V DC. The filtering is better than normal, with a 3-stage filter made up of C20 (24mF), C21 (50mF) and C22 (50mF). Karaoke ain’t new The stereogram has another couple of features that a few manufacturers, particularly Kriesler, often incorporated. Karaoke is not just a recent phenomena, as this receiver also had a built-in microphone so that you could sing along with your records. When operated, the microphone switch places the unit into the mono mode and a preset volume control adjusts the volume to prevent amplifier feedback. In addition, the set has a socket so that a stereo reel-to-reel tape recorder could be connected into the audio line before the volume controls. This means that tape recordings could be made from either the record player or the radio, depending on which of these two sources was selected. 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 1043 Email: evatco<at>pacific.net.au www.evatco.com.au January 2007  93 upwards or indicates an open circuit when the lead is flexed. That done, the set was connected to power and turned on. The dial lights and the valve heaters worked but nothing else. A quick check with a multimeter revealed HT voltage on capacitor C22 but there was nothing on C21. It wasn’t hard to find the reason – series resistor R23 was completely open circuit. A replacement resistor was quickly fitted and that fixed the problem – HT voltage now came up across C21 and the set burst into life. It sounded good too and the overall sensitivity of the receiver was quite reasonable. Cleaning the valves This radio chassis, shown here before restoration, is accessed by removing the top wooden cover from the cabinet before restoration. Note that the terminal block at bottom right catered for the 240VAC leads to the record changer, as well as the antenna and speaker leads. This means that care must be taken to rewire it correctly if any leads are removed during servicing. These two features were cheap to provide but just how often such facilities were used is debatable. In practice, they were probably rarely used, just like the shortwave section of most dual-wave radio receivers. Getting it going As shown in the lead photo, this particular unit’s cabinet is in quite good order. However, the electronic circuitry wasn’t working (the set was as dead as a dodo) and the record changer had a few mechanical problems. In fact, the record changer would not go through any of its automatic routines and stayed running until it was manually switched off. I began by giving the chassis and all other parts a good clean with a brush, to remove the dust. That done, I then had to work out how to get at the electronic circuitry. Initially, I tried to get the chassis out through the back of the cabinet but this proved unsuccessful. I could get at a few plugs, sockets and leads but not at the chassis itself, as it was mounted on top of a shelf. After looking around the set, I eventually spotted a screw which went from the record changer section and into the side of the section housing the circuitry. I removed it and found that I could then lift the top timber panel 94  Silicon Chip up and unhook it from two lugs on the inside of the side panel. This showed that the circuitry is mounted on two brackets rather than on a conventional chassis. The RF section can be removed but this also means that the dial drive assembly has to be dismantled. As a result, I decided to leave it in place and work on it using a small-tipped soldering iron. The audio amplifier and power supply are similarly difficult to work on but again I decided to leave it in place. A general check with my highvoltage tester did not reveal any excessive leakage or shorts anywhere that would stop me from trying to run the set. Once it was going properly, I could then replace any leaky capacitors in critical places. That said, this set has quite a sprinkling of polyester capacitors and these rarely show signs of leakage resistance. The set has a 3-core power lead and it’s always a good idea to first check that the earth wire in particular is not broken. That’s done simply by connecting a multimeter (set to a low ohms range) between the set’s chassis and the earth pin of the 3-pin plug. If all appears OK, try flexing the lead, particularly around the plug which is where breaks often occur. Replace the lead if the multimeter reading “flicks” Now that the set was working, I switched it off, removed all the valves and washed them in soapy water. This has to be done carefully, so that you don’t rub the type numbers off the valves. They were then rinsed in clean water and allowed to dry standing upright. Next, the valve sockets were sprayed with Inox (a cleaning lubricant), as were the variable controls and the switches. The dial mechanism was then oiled with light machine oil, after which the valves were replaced and the set put through its paces. All appeared well, so the set was left running to make sure no intermittent faults were lurking in the works. This set uses polyester capacitors in most critical areas but not for the AGC bypass capacitor (C10). Instead, this was a paper capacitor and it tested leaky (5MW), which meant that it had to be replaced. This involves undoing three screws on the underside of the RF sub-assembly and then tilting the assembly sufficiently to gain access to the capacitor’s leads. However, this must be done carefully, as the dial assembly is also attached to this subassembly. A 50V ceramic capacitor was installed in place of the original unit. Record changer The record changer used in the Philips RF5 is a Garrard Autoslim unit. As mentioned above, it would not go through any of its automatic operations and the reason for this was quite simple. Over time, much of the oil and grease that’s used to lubricate the mechanical parts had either congealed into sticky “globs” impregnated with siliconchip.com.au siliconchip.com.au Fig.1: the circuit is conventional and uses five valves in total – two in the radio front-end (a 6AN7 converter and a 6N8 IF amplifier/detector), two 6GW8 triode/pentodes for the audio amplifier stages & a 6V4 rectifier. dust or had disappeared altogether, leaving a lot of moving parts without lubrication. In order to clean away the old lubrication, the mechanism must first be removed from the cabinet and placed on a servicing jig so that its operation can be observed. Fortunately, it’s not difficult to get the changer out. First, you unplug the audio leads and disconnect the mains power lead from a terminal block at the rear of the receiver chassis plate. That done, the toggles that keep the changer in the cabinet are twisted so that they lay along the axis of the screw through the changer baseplate. The changer can then be lifted straight out of the cabinet and placed onto the servicing jig. Having done this, I removed the platter and turntable. The latter is released by first sliding off the retaining circlip, then twisting the turntable gently clockwise while lifting it upwards until it clears the centre post. There is virtually nothing that can go wrong with this and it was simply cleaned and the phosphor bronze bearings oiled. Next, I removed the motor from its resilient mounts by removing the three circlips holding it in place. The motor freely rotated, so there was no problem here. However, the felt wicks which hold oil for the phosphor bronze motor bearings were dry so I filled them with oil using a syringe-type “oiler”. The motor was then reinstalled. That done, a drop of oil was applied to the top of the phosphor bronze bearing on the idler (jockey) wheel. This is the large rubber wheel on the left of the photograph on the following page. Its purpose is to make contact with the inside rim of the turntable, to drive the turntable at the appropriate speed. In operation, the speed control varies its position vertically against a stepped-diameter pulley attached to the motor, depending on the speed of the record to be played (ie, the speed of the turntable depends on the pulleydiameter selected by the idler wheel). Next, a large gear on one side of the mechanism was removed, again by removing its circlip (this is the gear on the righthand side of the photograph of the turntable’s “works”). In this case, the grease on the cam on the underside of the gear had congealed and one of the small ancillary levers had seized due to lack of oil. I soaked this gear assembly in household kerosene, then cleaned the muck off and removed the small lever from its shaft by removing two more circlips. I then cleaned and oiled the shaft and replaced the lever, which now operated freely. Finally, I greased and oiled the remaining cams as appropriate and reassembled the unit. The turntable and platter were the last parts to go on. The turntable is installed by carefully lowering it over the centre post/ shaft while rotating it clockwise, until it settles into position. It’s important to only rotate it clockwise, otherwise damage can be done to the idler wheel. Final adjustments Once the turntable was back in January 2007  95 The Garrard record changer is shown here mounted on a simple servicing jig, with its turntable platter removed to give access to part of the mechanism. The servicing jig is nothing more than a drilled wooden base which accepts wooden dowels to support the turntable’s base. This underneath view of the pickup arm shows the locations of the stylus weight adjustment and the stylus drop position adjustment. A turnover cartridge is used so that both 33/45 RPM records & 78 RPM records can be played. place, I gave it a quick checkout on the test jig, to ensure everything was working properly. First, I adjusted the tracking weight of the stylus (this is done by adjusting a spring under the tonearm), then checked that it tracked a record correctly without skating. That done, the operation of the changer was observed in automatic mode. In particular, I checked that the stylus dropped down onto the record in the correct position; ie, in the middle of the run in track (if it doesn’t, this can be corrected by adjusting a horizontal screw near the tonearm pivot). I also checked that the tonearm lifted off correctly when it reached the run out at the end of the record and returned to its stand. By the way, most automatic record changers are designed to play up to six records in a stack. As a result, there is a cam adjustment under the turntable which sets the height to which the tonearm rises to ensure it will clear a complete stack on the platter. This rarely gets out of adjustment, so I didn’t bother to check it. Finally, I decided to replace the two styli for the turnover cartridge. Microgroove records require a 1 mil (.001-inch) radius stylus, while 78s require a 2.5 mil stylus. Unfortunately, I’m having trouble tracking down the 78 RPM stylus, so I’ve simply replaced the microgroove (33/45 RPM) stylus for the time being. Summary The Philips RF5 stereo radiogram is typical of the era. It delivers reasonable quality from the audio section and the RF section has good sensitivity if used SC with a fairly short antenna. Photo Gallery: Eclipse Monarch AN (1946) MANUFACTURED BY Eclipse Radio, Melbourne in 1946, the Monarch AN is a 5-valve superhet and is similar to the companion Astor model that uses the same chassis. It was housed in a stylish bakelite cabinet with a large circular dial towards the right and the three control knobs spaced along the bottom. The valve line-up was as follows: 6A8-G frequency changer; 6U7-G IF amplifier; 6B6G, audio amplifier/detector/ AVC rectifier; 6V6-G audio output; and 80 rectifier. Photo: Historical Radio Society of Australia, Inc. 96  Silicon Chip siliconchip.com.au 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 Pic-Toc clock questions I would like to build your PicToc clock, as described in the July 2001 issue. When comparing the schematic with the PC board layout, a few things are not clear to me. Why are 4-pin pushbutton switches on the PC board, while the schematic only shows 2-pin switches? Are 2-pin switches sufficient? I cannot follow the circuit logic: which pins on the switches should be closed when the switch is in neutral position (if any)? Pin 17 of the PIC is connected to pin 8 of DISP4 but not with pin 3 of this same DISP4, as it is shown on schematic. I don’t understand where the common pins of all four switches on the PC board are connected? (V. B., Rijeka, Croatia). • The pushbutton switches are single-pole momentary contact types. The four pins on the switches are necessary in this project because the top set are internally connected and so are the bottom set of pins. The interconnections then make links for the PC board connections so that they can straddle tracks. When the switch is pressed it makes contact between the top and bottom contacts. The displays have two common pins (3 & 8). Only one needs to be connected as they are internally wired together in the display. DISP4 shows pins 3 & 8 connected because they must be connected on the PC board as the internal connection between pins 3 & 8 is used as a link. FM receiver wanted for transmitter kit I was wondering if you could tell me of any suitable receivers for the Oatley K222 FM stereo transmitter kit. I plan to use it for a wireless microphone but I need a receiver that will have a line level output so I can plug headphones into it to monitor the sound and a microphone level output to plug into the video camera. I wouldn’t know how to modify an FM radio to have both levels of output so if you have any suggestions they would be much appreciated. I figured tapping into the signal before it’s amplified would do for the mic level, with the line level as per normal, but I wouldn’t know where the preamp signal would be. (D. W., via email). • Virtually any FM/AM radio with headphone outputs can be made to do the job. You would just need a voltage divider across each headphone output channel to derive the microphone signal. Each channel would require two resistors in the voltage divider, say 1kW and 22W to deck (0V). The microphone signal would be taken across the 22W resistors in each channel. Zapper needs a crook battery for testing I bought the Battery Zapper Mk.II kit as featured in the May 2006 issue and have put it together. I do not have a bad or dead battery, so to test it I connected it to my good car battery. All the LED indicators function as detailed in your test section, however the output voltage sits at around 13V. According to your test section, the output voltage should be around 30V and reduce slowly as the battery “recovers”. Am I getting a reading of 13V because the battery I have connected the Zapper to is good? I can hear a lowlevel buzzing noise which I assume is the sound created by the inductors No Support For ATtiny13 Or ATtiny2313 I recently built the AVR ISP serial programmer from the October 2002 issue of SILICON CHIP and I was curious to why it doesn’t support more devices like the ATtiny13 or ATtiny2313. Is there a way to program these other devices? (T. H., via email). • The ATtiny13 and ATtiny2313 were released well after the original AVR ISP project which is based on Atmel’s application note AVR910. Several hobbyists have updated the AVR ISP firmware to support faster programming and some newer devices. You might like to try the V3.8b firmware update from this site: www.mikrocontrollersiliconchip.com.au projekte.de (this is a German site, so use one of the on-line web page translators to access it). Note that to use this particular firmware update, you must adjust the crystal frequency and MOSI/MISO pin assignments to suit the programmer hardware. Unfortunately, Atmel no longer officially supports the AVR ISP. This means that they’re not updating AVRprog to support newer devices. The latest version available is V1.40, as supplied with AVR Studio V4.11. This version should allow you to program the ATtiny13, once you’ve updated the firmware in the AVR ISP as described above. Unfortunately, AVRprog V1.40 lacks support for the ATtiny2313. We’ve heard that the older V1.37 (as supplied with AVR Studio V3.56) does support the ATtiny2313, although we haven’t tried it. Alternatively, if you don’t mind using a command-line interface, try AVRDude v5.1 or later from http:// download.savannah.gnu.org/releases/avrdude Another option would be to purchase a genuine AVR-ISP MKII programmer, which supports all in-system programmable devices. You can get one of these from JED Microprocessors at www.jedmicro. com.au/avr.htm January 2007  97 Bridging Studio 350 Amplifier Modules I want to build an amplifier system into my JBL JRX 115 speaker, which has an 8W impedance and is rated at 250W RMS. I note that your Studio 350 develops only 200W into 8W. Can I use two amplifiers in bridge mode to get more power? (B. L., via email). • Building such an amplifier system would be a major undertaking and would require significant audio-related electronics experience but yes, it is possible. As a bare minimum, you’d need a set-up like that shown in the accompanying block diagram. As shown, a preamplifier boosts signal level ahead of a bridge adapter, which drives a pair of and implies that the unit is working. (S. P., via email). • Your relatively low voltage reading is probably due to the battery being “too good”, with virtually no sulphating and hence a very low impedance for the zapping pulses. The low-level buzzing sound is a good sign and indicates that the zapping is probably working correctly, as you suggest. No error in circuit I noted an error in the Suppressed Zero Meter circuit on page 7 of the November 2006 issue. The +Vin is connected to the 7905’s GND pin and 98  Silicon Chip amplifiers via its complementary signal outputs. Power for the preamplifier can be conveniently picked off from the bridge adapter’s ±16V supply, which is generated by on-board zener regulators fed from the amplifier’s DC power rails. With the speaker “bridged” between the two amplifier outputs, you can expect about twice the rated 4-ohm output power, so for the Studio 350, this amounts to about 700W RMS. Note that as each amplifier “sees” only half the loudspeaker impedance, you can only use an 8-ohm speaker in this configuration. Getting rid of the heat will be a its input is connected to 0V. Could you please confirm this as I would like to build this one and not blow up anything? (R. N., via email). • The circuit is correct. The 7905 is a negative 5V regulator and therefore its input and output terminals must be negative with respect to its GND terminal. Questions on the Mighty Midget I was looking at the Mighty Midget 70W amplifier (SILICON CHIP, March 2002) and was thinking of building two for a stereo set-up. I am thinking of running both off a toroidal transformer challenge for a powered speaker application. We expect that the amplifier enclosure would need to be built on to the speaker, rather inside it. It’s also a very good idea to include speaker protection (not shown) for any high-powered amplifier. Without protection, amplifier failure can easily destroy an expensive speaker in seconds. All modules are still available as kits. Check out Altronics for the preamp (K-5512), bridge adapter (K5565) and amplifier (K-5815). Jaycar also stock the preamp (KC-5159) and amplifier (KC-5372). with a suitable rectifier and filtering capacitors. How much current does the amplifier draw and what is the maximum voltage? The toroidal is a 12-0-12V 160VA unit capable of 13.33A when the secondaries are wired in parallel. Can you suggest capacitors for filtering the power output? Also, if both of the amplifier chips are installed on the same heatsink, do they have to be insulated from each other? (N. K., via email). • The TDA1562Q can accept a supply of up to 18V DC (maximum). The capacitors on the PC board should be rated at 25V if you give it more than 16V DC. siliconchip.com.au RF Modules Australia Suppliers of Low Power Wireless Connectivity Solutions throughout Australia, New Zealand & S.E Asia Radiometrix - Low Power Radio Modules. SENA - Bluetooth. WideCast - ZigBee. EmbeddedComms - Radio Modems. TM BiM1 VHF Transceiver 151.300MHz 100mW 173MHz for NZ Industrial i9600 Controller TX1H/RX1 TX2H/RX2 SIL Modules BiM2 (10mW) BiM2A (25mW) UHF Transceiver EmbeddedComms RMX232 Radio Modem VHF & UHF Parani-SD100 Parani-ESD100 Parani-ESD110 Antennas Telemetry IO Control RFMA Bluetooth Serial Bluetooth Adapters RoHS Compliant Bluetooth OEM Modules igBee EZBee-001 (10mW) Short Range (30m) Internal Chip Antenna Parani-SD200* *with optional battery pack Parani-ESD200 Parani-ESD210 EZBee-100 (100mW) Long Range (600m+) External Antenna ZigBee EZB-001EK Professional Evaluation Kit Applications: OEM Equipment Industrial control Building automation Personal area networks Wireless remote control sales<at>rfmodules.com.au www.rfmodules.com.au Low Power Wireless Connectivity Specialists Ph: 03-6331-6789 P.O. Box 1957, Launceston, TAS. 7250. Ph: 03-6331-6789. Fax: 03-6331-1243 RF Modules Australia The 12VAC transformer may deliver more than 18VDC (after rectification and filtering) when unloaded. Make sure that this is not the case even with a high mains voltage. Ideally, the transformer should be rated at 10V AC rather than 12V AC. The supply filter capacitors should be rated for a ripple current of at least 8A. Typically 4000mF 63V canister type electrolytics have a ripple rating of about 4A, so two or three of these would be suitable. Alternatively, use three or four 4700mF 25V PC-mount electrolytics. Use a 35A bridge rectifier. The TDA1562Q amplifier package is isolated from its pins and so you do not need to insulate between them or the heatsink. Re-using a notebook LCD as a monitor I am enquiring about the possibility of utilising an old notebook’s LCD as a standalone monitor, say for a desktop computer, with a VGA input or even better, with an RCA plug input. My actual use is for my multimedia siliconchip.com.au player monitor so I can build an MP3 jukebox without having to use a notebook. (A. M., via email). • Many recent notebooks include an external video input but we cannot see how it would be economically viable to add a video input to those that don’t. LCD panels often employ custom-designed, low-voltage digital interfaces (ie, they are not analog compatible). This means that you’d need an LCD controller (with VGA input) capable of driving your particular model of LCD panel. Such devices are available but will probably cost more than the price of a cheap LCD monitor. Noisy reception on AM car radio My car radio gives me clear reception on FM but gives me noisy static with AM. Is there a way I can clear this noise or reduce it? (F. S., via email). • This is not a topic we have dealt with in a magazine article but there are a number of questions you need to resolve. First, if you are plagued with ignition noise and alternator whine while the engine is running, it suggests that you need suppression components installed to eliminate this problem. AM radios are usually more sensitive to this problem than FM radios. A car radio installer can fix this. Second, if there is no engine noise but the sensitivity is poor, perhaps the antenna peaking capacitor for the radio has not been adjusted for optimum reception. Finally, it must be said that most AM radio sections in today’s car systems are pretty poor and nowhere near as good as they were when the radios were designed and manufactured in Australia. Priority switching for two amplifiers I was wondering if there was a circuit that exists (or could be modified) to allow a pair of speakers to be connected to two amplifiers with one having an “override” on the signal. For example, the speakers would receive the signal from amplifier 2 but as soon as a signal was detected from amplifier 1, then 2 would be cut off January 2007  99 VCRs For Security Systems The article by Murray Downes on page 46 of the September 2006 issue initially looked like the answer to my prayers, as I want to use a video recorder on my home and at my weekender to record each time the system at either property was triggered. Unfortunately, though, this article didn’t solve the problem in my case. The problem is using a video recorder as a security recorder. I’ve tried several methods of starting and stopping both Beta and VHS recorders, mainly using relays. However, I find that loading and unloading the tape each time the unit is activated is a waste of time and a potential cause of mechanical failure, even if the unit is left turned on permanently (waste of power also). I’m now sorry I gave away my and you would hear only what was broadcast on 1. I know various PAs do this at an input level but I’ve never seen it done at the output end. (P. I., Carlton North, Vic). • You could achieve this “priority” function quite easily by modifying the VOX circuit we featured in the September 1994 issue. This monitored the signal from an electret microphone and it closed a relay whenever a signal above a certain threshold was received by the microphone. You could adapt it by substituting a 10kW resistor for the microphone and couple the signal from your ampli- original piano key Sanyo Beta machine, as it may have filled the role. Scots-byterians like me can’t see why security recorders or cards for computers should be so expensive. I’m sure an article describing how to disarm the loading/unloading procedure so that VCRs can be used for this purpose would be of value to a lot of readers (or am I out of step?). I have a number of Beta (mainly Sony) and VHS recorders that I would like to fire up to record when the surveillance cameras fire up. (J. P., Epping, NSW). • We do not see how you can hook up a VCR in any security system without using relays in the way you describe – that will naturally involve loading and unloading the tape each time an event is to be re- fier via a 1kW resistor into the 0.1mF capacitor feeding diodes D1 & D2. Make sure you disconnect the 0.1mF capacitor from pin 1 of IC1a. You will need a DPDT relay to do the switching from one amplifier to the other. Using the slave trigger with two flash units I have successfully built the Slave Flash Trigger featured in the July 2003 issue. Is there a simple way in which it can be made to trigger two electronic flashes at the same time? I was think- corded. The only way to avoid that would be to modify the recorder so that the tape is always loaded (around the drum) but then you would presumably need a special tape-unloading procedure so that the cassette could be ejected from the machine when you want to do that. Such a modification could be very tricky since the whole tape loading/unloading procedure is normally under microprocessor control. Even if such a modification was successful, the VCR would still need to be permanently powered, otherwise short “events” might be missed. Hard disc video recorders get around this problem but they also need to be permanently powered. ing of connecting two identical flash units to it by combining their trigger cables into one with a simple adaptor, or possibly incorporating a diode into each flash lead to stop them interfering electrically with each other. (E. J., via email). • You might be able to trigger two flash units with the Slave Flash Trigger using an isolating diode in each flash lead, as you suggest. If this doesn’t work reliably, try fitting a second C106D SCR and diode bridge, to drive the second flash. The gate of the second SCR can be connected to the emitter of Q2, in parallel SC with the existing SCR’s gate. 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. 100  Silicon Chip siliconchip.com.au MARKET CENTRE Cash in your surplus gear. Advertise it here in Silicon Chip. CLASSIFIED ADVERTISING RATES Advertising rates for these pages: Classified ads: $27.00 (incl. GST) for up to 20 words plus 80 cents for each additional word. Display ads: $49.50 (incl. GST) per column centimetre (max. 10cm). Closing date: 5 weeks prior to month of sale. To book your classified ad, email the text to silicon<at>siliconchip.com.au and include your credit card details, or fax (02) 9939 2648, or post to Silicon Chip Classifieds, PO Box 139, Collaroy, NSW, Australia 2097. _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ Enclosed is my cheque/money order for $­__________ or please debit my o Bankcard   o Visa Card   o Master Card Card No. Signature­­­­___­­­­­­­­__________________________ Card expiry date______/______ Name _________________________________________________________ Little Devil Antennas Street _________________________________________________________ Suburb/town ______________________________ Postcode______________ Phone:______________ Fax:______________ Email:___________________ www.ldantennas.com.au Office: 03 62652148 Mobile: 0409136268 High Performance Antennas FOR SALE More control solutions for you! NEW Netiom UDP: a budget priced Ethernet card ($225) which you can use for control and monitoring. NEW Protocol Gateways: Lonworks to Modbus, Profibus to Modbus, Can(J1939) to Modbus, AB-DF1 to Modbus and more NEW Range of serial LCD displays and touch screens. Easily connected to a range of PLCs. NEW Low Cost Dual DC Amplifier Kit: perfect for Data Acquisition. Amplify signals from 1.5 to 10 or reduce signals by a factor of 0.7 to 0.1 siliconchip.com.au Serial Stepper Motor Controller card will now control motors up to 7500pps Motor Controllers from Pololu: we have a range of DC motor and servo motors.These motor controllers have been designed for robotic applications. Electronic Thermostats with digital temperature display; 2 control relays can be used in heating and cooling. NTC thermistor or J T/C or Pt100 sensors. Isolated and Non Isolated RS232 to RS485 converters. USB to RS422/RS485 converter with 1500V Isolation, RTS or Auto Data Flow control. Signal Conditioners non isolated and isolated: convert thermocouples, RTDs to 4-20mA or 0-10V. Fully programmable. Stepper Motors: we have a selection of stepper motors for hobby and high torque CNC applications. DC Motors for both hobby and high torque applications. DC, Stepper and Servo Motor controller kits. Serial and Parallel Port relay controller cards. PIC MicroProgrammers: serial and USB port operated. Switch Mode, Battery Chargers and DC-DC converters. Full details and credit card ordering January 2007  101 VIDEO - AUDIO - PC distribution amps - splitters digital standards converters - tbc's switchers - cables - adaptors genlockers - scan converters bulk vga cable - wallplates DVS5c & DVS5s High Performance Video / S-Video and Audio Splitters CLEVERSCOPE USB OSCILLOSCOPES 2 x 100MSa/s 10bit inputs + trigger 100MHz bandwidth 8 x digital inputs 4M samples/input Sig-gen + spectrum analyser Windows 98/Me/NT/2k/XP More frequent updates – every 2.5 seconds! More alarm settings – over 70 parameters! More highs, lows and graphs – over 80 in all! QUEST ® VGA Splitter VGS2 HQ VGA Cables AWP1 A-V Wallplate Come to the specialists... ELNEC IC PROGRAMMERS High quality Realistic prices Free software updates Large range of adaptors Windows 95/98/Me/NT/2k/XP EVER! MD12 Media Distribution Amplifier Quest AV® Best Home Weather Station . . . ® Quest Electronics® Pty Limited abn 83 003 501 282 t/a Questronix Products, Specials & Pricelist at www.questronix.com.au fax (02) 4341 2795 phone (02) 4343 1970 email: questav<at>questronix.com.au With the Vantage Pro2 Weather Station you get incredibly detailed information on: Wind – direction and strength Rainfall – current, recent patterns etc. Temperature – current, wind chill, etc. Barometric pressure – current and trends Humidity & dewpoint – current and 24 hrs And your own local forecast. You’ll be more accurate than the weather bureau! Available in wired or wireless models (wireless transmission up to 300m!) IMAGECRAFT C COMPILERS ANSI C compilers, Windows IDE AVR, TMS430, ARM7/ARM9 68HC08, 68HC11, 68HC12 GRANTRONICS PTY LTD www.grantronics.com.au Satellite TV Reception Unit 5, 17 Southfork Dve Kilsyth, Vic 3137 SPK360 3/5/06 1:10 PM Page 1 Tel: (03) 9761 7040 Fax (03) 9761 7050 hardware and software products available from over 40 world wide manufacturers, and authors. Olimex Development Boards & Tools: ARM, AVR, MAXQ, MSP430 and PIC. Atmel Programmers And Compilers: STK500, Codevision C, Bascom AVR, FED AVIDICY Pro, MikroElektronika Basic and Pascal, Flash File support, and boot loaders. PICmicro Programmers And Compilers: microEngineering Labs USB programmers, adapters, and Basic Compilers, DIY (Kitsrus) USB programmers, MikroElektronika Basic, Pascal, DSpic Pascal Compilers, CCS C, FED C, Hi-Tech C, MikroElektronika C, disassembler and hex tools. CAN: Lawicell CANUSB, CAN232 FTDI: USB Family of IC ‘s. FT232RL, FT2452RL, also BL and others. 4DSystems LCD/Graphics: Add VGA monitor, or OLED LCD to your micro. Simple Serial I/F. Heaps And Heaps Of USB Products: TTL, RS-232, RS-485, modules, cables, analyzers, CRO’s. Popular Easysync USB To RS-232 Cable: Works when the others fail. Only one recommended by CBUS. Money back guarantee. www.dontronics-shop.com 102  Silicon Chip 20 years experience! 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 HI-FISPEAKER REPAIRS YOUR EXPERT SPEAKER REPAIR SPECIALISTS Specialising in UK, US and Danish brands. Speakerbits are your vintage, rare and collectable speaker repair experts. Foam surrounds, voice coils, complete recone kits and more. Original OEM parts for Scan-Speak, Dynaudio, Tannoy, JBL, ElectroVoice and others! TAIG MACHINERY Micro Mini Lathes and Mills From $489.00 SPK360 www.dontronics.com has 300 selected 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°. tel: 03 9647 7000 www.speakerbits.com 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 available at www.oceancontrols.com. au Helping to put you in control. CENTRAL COAST FIELD DAY, Sunday 18th Feb. Don’t miss Australia’s biggest Amateur Radio exhibition and sale of new and used radio and communication equipment at Wyong Race course, just 1 hour north from Sydney. Gates open 8.30am. Special Field Day bargains from traders and tons of disposals gear in the flea market. Exhibits by clubs and groups with interests ranging from vintage radio, packet radio, scanning, amateur TV and satellite. www.ccarc. org.au. Ph (02) 4340 2500. AMPLIFIER BUILDERS; ezChassis® pre-punched cabinets make all your DIY amplifier projects easier and professional looking. Matching heatsinks, handles and sockets. www.designbuildlisten.com siliconchip.com.au Do You Eat, Breathe and Sleep TECHNOLOGY? Opportunities for full-time and part-time positions all over Australia & New Zealand Jaycar Electronics is a rapidly growing, Australian owned, international retailer with more than 39 stores in Australia and New Zealand. Our aggressive expansion programme has resulted in the need for dedicated individuals to join our team to assist us in achieving our goals. We pride ourselves on the technical knowledge of our staff. Do you think that the following statements describe you? Please put a tick in the boxes that do: Knowledge of electronics, particularly at component level. Assemble projects or kits yourself for car, computer, audio, etc. Have empathy with others who have the same interest as you. May have worked in some retail already (not obligatory). Have energy, enthusiasm and a personality that enjoys helping people. Appreciates an opportunity for future advancement. Have an eye for detail. Why not do something you love and get paid for it? Please write or email us with your details, along with your C.V. and any qualifications you may have. We pay a competitive salary, sales commissions and have great benefits like a liberal staff purchase policy. Send to: Retail Operations Manager - Jaycar Electronics Pty Ltd P.O. Box 6424 Silverwater NSW 1811 Email: jobs<at>jaycar.com.au Jaycar Electronics is an equal opportunity employer and actively promotes staff from within the organisation. Applications: NEW! BiM2A Rural UHF FM Transceiver Multichannel Radio Modem Utilities Stock Arriving In Stock NOW! Industrial Range: 500m+ Range: 200m Power: 25mW Power: 10mW Commercial Data rate 64kbps TTL Serial 9600 baud Government 33mm x 23mm x 4mm 5 Channels. Addressable Meter Reading RADIOMETRIX: Low Power, Licence Exempt Radio Modules TDL2A-433-9 RF Modules Australia. P.O. Box 1957 Launceston, TAS., 7250. Ph: 03-6331-6789. Email: sales<at>rfmodules.com.au. Web: rfmodules.com.au PCBs MADE, ONE OR MANY. Any format, hobbyists welcome. Sesame Electronics Phone (02) 9593 1025. sesame<at>sesame.com.au www.sesame.com.au SWITCHMODE 5V reg. module kit just $6, or $7 built. 10.5 inch 7-segment display kit from $30. LEDs, nixies, kits, lots of other stuff. www.ledsales.com.au WANTED WANTED: EARLY HIFIs, AMPLIFIERS, Speakers, Turntables, Valves, Books, Quad, Leak, Pye, Lowther, Ortofon, SME, Western Electric, Altec, Marantz, McIntosh, Tannoy, Goodmans, Wharfedale, radio and wireless. Collector/ siliconchip.com.au Altronics.................................. 72-75 Amateur Scientist CDs............. OBC Alternative Technology Assoc. ....... 7 Av-Comm................................... 102 BitScope Designs......................... 27 Dontronics.................................. 102 Low Power Wireless Connectivity Specialists 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 555 Electronics............................. 47 Dick Smith Electronics............ 16-21 RFMA RF Modules Australia CLEARING ALL STOCKS of throughhole ICs for free. You pay $2.00 for post & pack. Limit 10 per customer. Go to www.lazar.com.au Advertising Index Parallax Basic Stamps The awesome simultasking 8-core Propeller Chip. Lots of sensors and Development kits + Robots. Ultrasonics, PIR accelerometer. Serial LCD display, serial keypads. Stepper Motor Controllers & Motors Micro stepping up to 25,600 fully protected industrial grade controllers at incredible prices. PCB mount units with full 32 bit indexer capability. DIN rail mount controller for factory applications. See our website for details and PDF file. Call or email us for application assistance. ron<at>nollet.com.au R T Nollet: Ph (03) 9338 3306; fax (03) 9338 4596; mobile 0407 804 712. www.nollet.com.au Hobbyist will pay cash. (07) 5471 1062. johnmurt<at>highprofile.com.au KIT ASSEMBLY NEVILLE WALKER KIT ASSEMBLY & REPAIR: • Australia wide service • Small production runs • Specialist “one-off” applications Phone Neville Walker (07) 3857 2752 Email: flashdog<at>optusnet.com.au Ecowatch.................................... 102 Elan Audio.................................... 91 Evatco.......................................... 93 FreeNet Antennas...................... 101 Grantronics................................. 102 Harbuch Electronics..................... 90 Instant PCBs.............................. 102 Jaycar ....................... IFC,49-56,103 JED Microprocessors..................... 5 Little Devil Antennas.................. 101 LN Marketing................................ 85 Microgram...................................... 3 MicroZed Computers.................... 89 Ocean Controls.......................... 101 Oatley Electronics........................ 83 Quest Electronics....................... 102 RCS Radio................................. 103 RF Modules........................... 99,103 RS Components............................. 6 RTN............................................ 103 Sesame Electronics.................. 103 SC – Radio & Hobbies DVD......... 15 Silicon Chip Binders................ 10,86 Silicon Chip Bookshop........ 104,IBC Silicon Chip Subscriptions........... 57 Speakerbits................................ 102 Taig Machinery........................... 102 Trusys............................................. 7 WES Components........................ 45 PC Boards Printed circuit boards for SILICON CHIP designs can be obtained from RCS Radio Pty Ltd. Phone (02) 9738 0330. Fax (02) 9738 0334. January 2007  103 ALL S ILICON C HIP SUBSCRIBERS – PRINT, OR BOTH – AUTOMATICALLY QUALIFY FOR A REFERENCE $ave 10%ONLINE DISCOUNT ON ALL BOOK OR PARTSHOP PURCHASES. CHIP BOOKSHOP 10% (Does not apply to subscriptions) SILICON For the latest titles and information, please refer to our website books page: www.siliconchip.com.au/Shop/Books PIC MICROCONTROLLERS: know it all SELF ON AUDIO Multiple authors $85.00 The best of subjects Newnes authors have written over the past few years, combined in a one-stop maxi reference. Covers introduction to PICs and their programming in Assembly, PICBASIC, MBASIC & C. 900+ pages. PROGRAMMING and CUSTOMIZING THE PICAXE By David Lincoln (2nd Ed, 2011) $65.00* A great aid when wrestling with applications for the PICAXE See series of microcontrollers, at beginner, intermediate and Review April advanced levels. Every electronics class, school and library should have a copy, along with anyone who works with PICAXEs. 300 pages in paperback. 2011 PIC IN PRACTICE by D W Smith. 2nd Edition - published 2006 $60.00* Based on popular short courses on the PIC, for professionals, students and teachers. Can be used at a variety of levels. An ideal introduction to the world of microcontrollers. 255 pages in paperback. PIC MICROCONTROLLER – your personal introductory course By John Morton 3rd edition 2005. $60.00* A unique and practical guide to getting up and running with the PIC. It assumes no knowledge of microcontrollers – ideal introduction for students, teachers, technicians and electronics enthusiasts. Revised 3rd edition focuses entirely on re-programmable flash PICs such as 16F54, 16F84 12F508 and 12F675. 226 pages in paperback. by Douglas Self 2nd Edition 2006 $69.00* A collection of 35 classic magazine articles offering a dependable methodology for designing audio power amplifiers to improve performance at every point without significantly increasing cost. Includes compressors/limiters, hybrid bipolar/FET amps, electronic switching and more. 467 pages in paperback. SMALL SIGNAL AUDIO DESIGN By Douglas Self – First Edition 2010 $95.00* The latest from the Guru of audio. Explains audio concepts in easy-to-understand language with plenty of examples and reasoning. Inspiration for audio designers, superb background for audio enthusiasts and especially where it comes to component peculiarities and limitations. Expensive? Yes. Value for money? YES! Highly recommended. 558 pages in paperback. AUDIO POWER AMPLIFIER DESIGN HANDBOOK by Douglas Self – 5th Edition 2009 $85.00* "The Bible" on audio power amplifiers. Many revisions and updates to the previous edition and now has an extra three chapters covering Class XD, Power Amp Input Systems and Input Processing and Auxiliarly Subsystems. Not cheap and not a book for the beginner but if you want the best reference on Audio Power Amps, you want this one! 463 pages in paperback. DVD PLAYERS AND DRIVES by K.F. Ibrahim. Published 2003. $71.00* OP AMPS FOR EVERYONE By Bruce Carter – 4th Edition 2013 $83.00* This is the bible for anyone designing op amp circuits and you don't have to be an engineer to get the most out of it. It is written in simple language but gives lots of in-depth info, bridging the gap between the theoretical and the practical. 281 pages, A guide to DVD technology and applications, with particular focus on design issues and pitfalls, maintenance and repair. Ideal for engineers, technicians, students of consumer electronics and sales and installation staff. 319 pages in paperback. by Sanjaya Maniktala, Published April 2012. $83.00 Thoroughly revised! The most comprehensive study available of theoretical and practical aspects of controlling and measuring EMI in switching power supplies. Subtitled Exploring the PIC32, a Microchip insider tells all on this powerful PIC! Focuses on examples and exercises that show how to solve common, real-world design problems quickly. Includes handy checklists. FREE CD-ROM includes source code in C, the Microchip C30 compiler, and MPLAB SIM. 400 pages paperback. By Garry Cratt – Latest (7th) Edition 2008 $49.00 Written in Australia, for Australian conditions by one of Australia's foremost satellite TV experts. If there is anything you wanted to know about setting up a satellite TV system, (including what you can't do!) it's sure to be covered in this 176-page paperback book. See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* PRACTICAL GUIDE TO SATELLITE TV See Review March 2010 ELECTRIC MOTORS AND DRIVES By Austin Hughes & Bill Drury - 4th edition 2013 $59.00* This is a very easy to read book with very little mathematics or formulas. It covers the basics of all the main motor types, DC permanent magnet and wound field, AC induction and steppers and gives a very good description of how speed control circuits work with these motors. Soft covers, 444 pages. NEWNES GUIDE TO TV & VIDEO TECHNOLOGY By KF Ibrahim 4th Edition (Published 2007) $49.00 It's back! Provides a full and comprehensive coverage of video and television technology including HDTV and DVD. Starts with fundamentals so is ideal for students but covers in-depth technologies such as Blu-ray, DLP, Digital TV, etc so is also perfect for engineers. 600+ pages in paperback. RF CIRCUIT DESIGN by Chris Bowick, Second Edition, 2008. $63.00* The classic RF circuit design book. RF circuit design is now more important that ever in the wireless world. In most of the wireless devices that we use there is an RF component – this book tells how to design and integrate in a very practical fashion. 244 pages in paperback. PRACTICAL RF HANDBOOK AC MACHINES By Jim Lowe Published 2006 $66.00* Applicable to Australian trades-level courses including NE10 AC Machines, NE12 Synchronous Machines and the AC part of NE30 Electric Motor Control and Protection. Covering polyphase induction motors, singlephase motors, synchronous machines and polyphase motor starting. 160 pages in paperback. PRACTICAL VARIABLE SPEED DRIVES & POWER ELECTRONICS Se e by Malcolm Barnes. 1st Ed, Feb 2003. $73.00* Review An essential reference for engineers and anyone who wishes to design or use variable speed drives for induction motors. 286 pages in soft cover. Feb 2003 BUILD YOUR OWN ELECTRIC MOTORCYCLE by Carl Vogel. Published 2009. $40.00* by Ian Hickman. 4th edition 2007 $61.00* Alternative fuel expert Carl Vogel gives you a hands-on guide with A guide to RF design for engineers, technicians, students and enthusiasts. the latest technical information and easy-to-follow instructions Covers key topics in RF: analog design principles, transmission lines, for building a two-wheeled electric vehicle – from a streamlined couplers, transformers, amplifiers, oscillators, modulation, transmitters and scooter to a full-sized motorcycle. 384 pages in soft cover. receivers, propagation and antennas. 279 pages in paperback. *NOTE: ALL PRICES ARE PLUS P&P – AUSTRALIA ONLY: $10.00 per order; NZ – $AU12.00 PER BOOK; REST OF WORLD $AU18.00 PER BOOK To Place Your Order: INTERNET (24/7) PAYPAL (24/7) eMAIL (24/7) www.siliconchip. com.au/Shop/Books Use your PayPal account silicon<at>siliconchip.com.au silicon<at>siliconchip.com.au with order & credit card details FAX (24/7) MAIL (24/7) Your order and card details to Your order to PO Box 139 Collaroy NSW 2097 (02) 9939 2648 with all details PHONE – (9-5, Mon-Fri) Call (02) 9939 3295 with with order & credit card details You can also order and pay for books by cheque/money order (Mail Only). Make cheques payable to Silicon Chip Publications. ALL TITLES SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST ALL S ILICON C HIP SUBSCRIBERS – PRINT, OR BOTH – AUTOMATICALLY QUALIFY FOR A REFERENCE $ave 10%ONLINE DISCOUNT ON ALL BOOK OR PARTSHOP PURCHASES. CHIP BOOKSHOP 10% (Does not apply to subscriptions) SILICON For the latest titles and information, please refer to our website books page: www.siliconchip.com.au/Shop/Books PIC MICROCONTROLLERS: know it all SELF ON AUDIO Multiple authors $85.00 The best of subjects Newnes authors have written over the past few years, combined in a one-stop maxi reference. Covers introduction to PICs and their programming in Assembly, PICBASIC, MBASIC & C. 900+ pages. PROGRAMMING and CUSTOMIZING THE PICAXE By David Lincoln (2nd Ed, 2011) $65.00* A great aid when wrestling with applications for the PICAXE See series of microcontrollers, at beginner, intermediate and Review April advanced levels. Every electronics class, school and library should have a copy, along with anyone who works with PICAXEs. 300 pages in paperback. 2011 PIC IN PRACTICE by D W Smith. 2nd Edition - published 2006 $60.00* Based on popular short courses on the PIC, for professionals, students and teachers. Can be used at a variety of levels. An ideal introduction to the world of microcontrollers. 255 pages in paperback. PIC MICROCONTROLLER – your personal introductory course By John Morton 3rd edition 2005. $60.00* A unique and practical guide to getting up and running with the PIC. It assumes no knowledge of microcontrollers – ideal introduction for students, teachers, technicians and electronics enthusiasts. Revised 3rd edition focuses entirely on re-programmable flash PICs such as 16F54, 16F84 12F508 and 12F675. 226 pages in paperback. by Douglas Self 2nd Edition 2006 $69.00* A collection of 35 classic magazine articles offering a dependable methodology for designing audio power amplifiers to improve performance at every point without significantly increasing cost. Includes compressors/limiters, hybrid bipolar/FET amps, electronic switching and more. 467 pages in paperback. SMALL SIGNAL AUDIO DESIGN By Douglas Self – First Edition 2010 $95.00* The latest from the Guru of audio. Explains audio concepts in easy-to-understand language with plenty of examples and reasoning. Inspiration for audio designers, superb background for audio enthusiasts and especially where it comes to component peculiarities and limitations. Expensive? Yes. Value for money? YES! Highly recommended. 558 pages in paperback. AUDIO POWER AMPLIFIER DESIGN HANDBOOK by Douglas Self – 5th Edition 2009 $85.00* "The Bible" on audio power amplifiers. Many revisions and updates to the previous edition and now has an extra three chapters covering Class XD, Power Amp Input Systems and Input Processing and Auxiliarly Subsystems. Not cheap and not a book for the beginner but if you want the best reference on Audio Power Amps, you want this one! 463 pages in paperback. DVD PLAYERS AND DRIVES by K.F. Ibrahim. Published 2003. $71.00* OP AMPS FOR EVERYONE By Bruce Carter – 4th Edition 2013 $83.00* This is the bible for anyone designing op amp circuits and you don't have to be an engineer to get the most out of it. It is written in simple language but gives lots of in-depth info, bridging the gap between the theoretical and the practical. 281 pages, A guide to DVD technology and applications, with particular focus on design issues and pitfalls, maintenance and repair. Ideal for engineers, technicians, students of consumer electronics and sales and installation staff. 319 pages in paperback. by Sanjaya Maniktala, Published April 2012. $83.00 Thoroughly revised! The most comprehensive study available of theoretical and practical aspects of controlling and measuring EMI in switching power supplies. Subtitled Exploring the PIC32, a Microchip insider tells all on this powerful PIC! Focuses on examples and exercises that show how to solve common, real-world design problems quickly. Includes handy checklists. FREE CD-ROM includes source code in C, the Microchip C30 compiler, and MPLAB SIM. 400 pages paperback. By Garry Cratt – Latest (7th) Edition 2008 $49.00 Written in Australia, for Australian conditions by one of Australia's foremost satellite TV experts. If there is anything you wanted to know about setting up a satellite TV system, (including what you can't do!) it's sure to be covered in this 176-page paperback book. See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* PRACTICAL GUIDE TO SATELLITE TV See Review March 2010 ELECTRIC MOTORS AND DRIVES By Austin Hughes & Bill Drury - 4th edition 2013 $59.00* This is a very easy to read book with very little mathematics or formulas. It covers the basics of all the main motor types, DC permanent magnet and wound field, AC induction and steppers and gives a very good description of how speed control circuits work with these motors. Soft covers, 444 pages. NEWNES GUIDE TO TV & VIDEO TECHNOLOGY By KF Ibrahim 4th Edition (Published 2007) $49.00 It's back! Provides a full and comprehensive coverage of video and television technology including HDTV and DVD. Starts with fundamentals so is ideal for students but covers in-depth technologies such as Blu-ray, DLP, Digital TV, etc so is also perfect for engineers. 600+ pages in paperback. RF CIRCUIT DESIGN by Chris Bowick, Second Edition, 2008. $63.00* The classic RF circuit design book. RF circuit design is now more important that ever in the wireless world. In most of the wireless devices that we use there is an RF component – this book tells how to design and integrate in a very practical fashion. 244 pages in paperback. PRACTICAL RF HANDBOOK AC MACHINES By Jim Lowe Published 2006 $66.00* Applicable to Australian trades-level courses including NE10 AC Machines, NE12 Synchronous Machines and the AC part of NE30 Electric Motor Control and Protection. Covering polyphase induction motors, singlephase motors, synchronous machines and polyphase motor starting. 160 pages in paperback. PRACTICAL VARIABLE SPEED DRIVES & POWER ELECTRONICS Se e by Malcolm Barnes. 1st Ed, Feb 2003. $73.00* Review An essential reference for engineers and anyone who wishes to design or use variable speed drives for induction motors. 286 pages in soft cover. Feb 2003 BUILD YOUR OWN ELECTRIC MOTORCYCLE by Carl Vogel. Published 2009. $40.00* by Ian Hickman. 4th edition 2007 $61.00* Alternative fuel expert Carl Vogel gives you a hands-on guide with A guide to RF design for engineers, technicians, students and enthusiasts. the latest technical information and easy-to-follow instructions Covers key topics in RF: analog design principles, transmission lines, for building a two-wheeled electric vehicle – from a streamlined couplers, transformers, amplifiers, oscillators, modulation, transmitters and scooter to a full-sized motorcycle. 384 pages in soft cover. receivers, propagation and antennas. 279 pages in paperback. *NOTE: ALL PRICES ARE PLUS P&P – AUSTRALIA ONLY: $10.00 per order; NZ – $AU12.00 PER BOOK; REST OF WORLD $AU18.00 PER BOOK To Place Your Order: INTERNET (24/7) PAYPAL (24/7) eMAIL (24/7) www.siliconchip. com.au/Shop/Books Use your PayPal account silicon<at>siliconchip.com.au silicon<at>siliconchip.com.au with order & credit card details FAX (24/7) MAIL (24/7) Your order and card details to Your order to PO Box 139 Collaroy NSW 2097 (02) 9939 2648 with all details PHONE – (9-5, Mon-Fri) Call (02) 9939 3295 with with order & credit card details You can also order and pay for books by cheque/money order (Mail Only). Make cheques payable to Silicon Chip Publications. ALL TITLES SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST