Silicon ChipJune 2004 - Silicon Chip Online SILICON CHIP
  1. Outer Front Cover
  2. Contents
  3. Publisher's Letter: Macrovision on DVDs is not "Merchantable Quality"
  4. Feature: Instrument Landing Systems: How They Work by Daniel Field
  5. Review: Microsoft Flight Simulator 2004 by Ross Tester
  6. Project: Dr Video Mk.2: An Even Better Video Stabiliser by Jim Rowe
  7. Review: Encarta 2004 Multimedia Encyclopaedia by Peter Smith
  8. Project: An RFID Security Module by Peter Smith
  9. Project: Fridge-Door Open Alarm by John Clarke
  10. Project: Courtesy Light Delay For Cars by John Clarke
  11. Feature: How Much Power Are Your Appliances Using? by Peter Smith
  12. Project: Automating PC Power-Up by Peter Smith
  13. Project: Upgraded Software For The EPROM Programmer by Jim Rowe
  14. Vintage Radio: Restoration tips and techniques by Rodney Champness
  15. Advertising Index
  16. Book Store
  17. Outer Back Cover

This is only a preview of the June 2004 issue of Silicon Chip.

You can view 17 of the 96 pages in the full issue, including the advertisments.

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Items relevant to "Dr Video Mk.2: An Even Better Video Stabiliser":
  • Dr Video Mk2 PCB [02106041] (AUD $10.00)
  • Dr. Video MkII Video Stabiliser PCB pattern (PDF download) [02106041] (Free)
  • Dr. Video MkII front and rear panel artwork (PDF download) (Free)
Items relevant to "An RFID Security Module":
  • AT90S2313 firmware and source code for the RFID Security Module (Software, Free)
  • RFID Security Module PCB pattern (PDF download) [03106041] (Free)
Items relevant to "Fridge-Door Open Alarm":
  • Fridge-Door Open Alarm PCB pattern (PDF download) [03206041] (Free)
Items relevant to "Courtesy Light Delay For Cars":
  • Courtesy Light Delay PCB pattern (PDF download) [05106041] (Free)
  • Courtesy Light Delay front panel artwork (PDF download) (Free)
Items relevant to "Upgraded Software For The EPROM Programmer":
  • Upgraded Software for the EPROM Programmer (Free)
  • Windows-Based EPROM Programmer PCB patterns (PDF download) [07112021-5] (Free)
  • Panel artwork for the Windows-Based EPROM Programmer (PDF download) (Free)
Articles in this series:
  • A Windows-Based EPROM Programmer (November 2002)
  • A Windows-Based EPROM Programmer; Pt.2 (December 2002)
  • A Windows-Based EPROM Programmer; Pt.3 (February 2003)
  • Upgraded Software For The EPROM Programmer (June 2004)

Purchase a printed copy of this issue for $10.00.
SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.jaycar.com.au Contents Vol.17, No.6; June 2004 www.siliconchip.com.au FEATURES 8 Instrument Landing Systems: How They Work How do commercial aircraft find the right landing point on the right runway in all sorts of weather? – by Daniel Field 18 Review: Microsoft Flight Simulator 2004 Want to learn to fly? You don’t have to leave the ground and you can fly lots of different aircraft – by Ross Tester 35 Review: Encarta 2004 Multimedia Encyclopaedia Latest offering from Microsoft packs more than an equivalent 60-volume printed set onto a single DVD (or four CDs)! 76 How Much Power Are Your Appliances Using? Want to check the power consumption of your appliances? Power-Mate makes it easy and you can check lots of other things as well – by Peter Smith Dr Video Mk.2 – Page 24. RFID Security Module – Page 38. PROJECTS TO BUILD 24 Dr Video Mk.2: An Even Better Video Stabiliser Clean up those copy protection “nasties” and get a rock-solid picture from your DVD player or VCR – by Jim Rowe 38 An RFID Security Module No more codes and no more keys; just wave a key tag to open doors and control security systems – by Peter Smith 59 Fridge-Door Open Alarm It beeps if the fridge door is left open for too long or hasn’t closed properly, to stop food from spoiling. There are lots of other uses as well – by John Clarke 71 Courtesy Light Delay For Cars Simple circuit has an adjustable delay from 7-40s and fades the lights out at the end of the delay period. And the same circuit suits all cars – by John Clarke 77 Automating PC Power-Up Tired of pressing the power switch to boot your PC after mains power has been applied? This simple modification does the job for you – by Peter Smith 82 Upgraded Software For The EPROM Programmer It fixes the bugs and can be downloaded from our website – by Jim Rowe SPECIAL COLUMNS 54 Serviceman’s Log TV sets that buzz and hum – by the TV Serviceman 64 Circuit Notebook Fridge Alarm – Page 59. (1) Voice Bandwidth Filter; (2) Fluoro Ballast; (3) Surveillance Camera Recorder; (4) Experimental Pendulum Clock; (5) Handy Time Delay With Relay Output 84 Vintage Radio Restoration tips and techniques – by Rodney Champness DEPARTMENTS 2 4 53 79 81 Publisher’s Letter Mailbag Order Form Product Showcase Silicon Chip Weblink siliconchip.com.au 90 92 93 96 Ask Silicon Chip Notes & Errata Market Centre Ad Index Courtesy Light Delay – Page 71. June 2004  1 PUBLISHER’S LETTER www.siliconchip.com.au Publisher & Editor-in-Chief Leo Simpson, B.Bus., FAICD Production Manager Greg Swain, B.Sc.(Hons.) Technical Staff John Clarke, B.E.(Elec.) Peter Smith Ross Tester Jim Rowe, B.A., B.Sc, VK2ZLO Reader Services Ann Jenkinson Advertising Enquiries Leo Simpson Phone (02) 9979 5644 Fax (02) 9979 6503 Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Julian Edgar, Dip.T.(Sec.), B.Ed 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: $76.00 per year in Australia. For overseas rates, see the subscription page in this issue. Macrovision on DVDs is not “Merchantable Quality” This month we are presenting a new version of our very popular Dr Video project which was originally featured in the April 2001 issue. The original version proved very effective at removing that bane of many DVD users – Macrovision copy protection signals. But, copy protection is a moving target and Macrovision has since become even more devious and it must be said, even more difficult for ordinary TV sets to work with. So we have produced the Mk.II version of the Dr Video circuit. It works very well in removing Macrovision signals so that all DVDs can once again be watched on normal TV sets and video projectors. Perhaps you have a late-model TV set that does not have a problem when you’re watching DVDs. Then you are fortunate. But if you have a set more than a couple of years old or one of the large-screen TVs that display the picture at 100 fields per second (100Hz) to reduce flicker (or a video projector that performs line and pixel doubling to improve picture clarity), that can be a different matter entirely. Macrovision plays merry hell with them, to the extent that the picture can be unwatchable. If you have one of these sets or projectors, the only way to get a steady picture is to somehow remove these extraneous pulses. The idea is to ‘clean up’ the video signal and let the TV set’s internal sync circuitry do its normal job without interference. That’s exactly what our Dr Video project is designed to do. Note that we are not suggesting that you use Dr Video to enable you to make copies of DVDs. In fact, there are other ways around it. Nor do we think that very many DVDs are being copied – most people just couldn’t be bothered. What we are doing is presenting a way to make DVDs work with normal TVs. But is this the correct remedy for what is effectively a faulty product? Absolutely not. Why should anyone need to build or buy a device to remove Macrovision signals so you can watch a movie that you have legitimately purchased? This proposition is ludicrous but that is what has happened. What consumers should do is to return all such DVDs to the place where they purchased them and ask for their money back. After all, if a DVD cannot be watched it is not “merchantable quality” and not suitable for sale. If enough consumers did return these “faulty” DVDs, Macrovision would soon be a thing of the past. Leo Simpson Editorial & advertising offices: Unit 8, 101 Darley St, Mona Vale, NSW 2103. Postal address: PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 9979 5644. Fax (02) 9979 6503. E-mail: silchip<at>siliconchip.com.au ISSN 1030-2662 * Recommended and maximum price only. 2  Silicon Chip siliconchip.com.au It’s the end of the financial year! TV on your Monitor Just connect the box in series between the computer and the monitor. You can watch TV without turning on the PC or you can watch TV in a window while working on your PC. Cat. 3525-7 $239 (Spend it before the tax man cometh!) Bluetooth GPS PCI Watchdog If your application program locks up, this card will apply a hardware reset to the computer after a selectable period. Cat. 17070-7 $299 CF to IDE Adapter A small adapter that allows a CF card to be plugged straight into an IDE port on your motherboard. Cat. 6771-7 $45 3.3v Printer Card An ECP/EPP/SPP printer card using the PCI BUS for 3.3 Volt systems. Cat. 2871-7 $169 Eprom Eraser Combining good performance and low cost, this EPROM eraser accommodates 4 devices and up to 40 pin packages. Cat. 3104-7 $258 Turn your PDA, Smartphone or laptop into a GPS This GPS is perfect for mobile users. It has a bluetooth connection and works with any bluetooth enabled device that can use GPS software. The unit has a rechargeable Lithium battery that lasts up to 8 hours. Cat. 11433-7 $469 RFID Reader/Controller Fast POS Thermal Printer A very fast thermal printer that literally churns out the receipt at 180 mm/s or 60 lps. Cat. 9178-7 $799 This is an integrated RFID Controller, proximity cardreader and door lock driver. There is also provision for an alarm loop and a push button connection. Cat. 1008081-7 $349 Low Profile USB 2.0 Card USB Gameport Adapter Provides 2 external and 1 internal USB 2.0 port. Cat. 2866-7 $59 Use your favorite game controller, joy stick, etc through your USB port. Cat. 9152-7 $69 15" LCD Terminal 2 way KVM with sound Front Access Video Editing Allows one keyboard, monitor and mouse to control 2 PCs. Switches the sound as well as the KVM. Includes 1.2m cables. Cat. 11669-7 $139 This great capture card comes with a front access bay for easy access. Captures analogue and digital signals. Cat. 23027-7 $399 This innovative unit is a 15" LCD monitor with a Windows Based Terminal built into it. A great look and a great space saving solution. Cat. 1215-7 $1699 PC Share Switch 2.5" HDD External Case This intelligent switch allows two sets of keyboard/monitor/mouse to control one PC. Cat. 11667-7 $139 Turn you laptop HDD into a portable drive with this USB 2.0 external case. Cat. 6710-7 $129 2.2Gb Compact Flash Drive This Type II Compact Flash drive can hold up to 2.2Gb making it a great storage solution for many portable devices. Cat. 6793-7 $459 Laser Barcode Scanner This stylish handheld laser scanner, has a great look at a great price. Cat. 1008039-7 $399 Video Chat Kit This kit comes complete with USB web-cam/microphone, headphones and software. Cat. 3541-7 $149 Thin Client Terminals! We’ve got them for Serial, Ethernet, Windows Based and Linux applications MicroGram Computers Ph: (02) 4389 8444 FreeFax: 1800 625 777 Vamtest Pty Ltd trading as MicroGram Computers ABN 60 003 062 100, info<at>mgram.com.au 1/14 Bon Mace Close, Berkeley Vale NSW 2261 All prices subject to change without notice. For current pricing visit our website. Pictures are indicative only. See all these products & more on our website...www.mgram.com.au SHOREAD/MGRM0604 Dealer inquiries welcome MAILBAG Valve electronics never reached the peak I believe recent discussion about valve amplifiers has been missing several points. Valve technology has never been fully developed and your recent design of a valve preamplifier is a good example of how modern circuit design can be used with valves. Just imagine how far valve design could have been developed if the transistor was not discovered for several more decades. I don’t believe valves were at the peak of their design life when the transistor came in. Electronics was just starting and its growth in complexity still could have happened with valves as its active component. The engineers of that time would have loved to have the cheapness of components, the technology to manufacture small and complex devices that we have now and the test equipment and the Spice programs we have to work with. Valves and transistors both have their good and bad points and should be used to their best advantage. Grahame Macpherson, Redcliffe, Qld. NOAA satellite receiver is excellent Jim Rowe’s articles on receiving NOAA weather satellites in the December 2003 and January 2004 issues are superb and have come at a good time for me. I had been considering assembling economical NOAA weather satellite receiving stations for use in schools but the big sticking point has been an economical suitable wide-bandwidth FM receiver. Jim’s economical kitset receiver has filled the gap. On the subject of suitable software to run a NOAA APT weather satellite receiving station, may I also mention a superb computer program which was absent from Jim’s comprehensive list in his first article. That program is “WXtoImg” which I currently use and which I believe is so exceptionally good that it rates a special mention. WXtoImg has many clever features, including automatic Web page crea4  Silicon Chip tion and upload, optional precision computer clock timekeeping via GPS receiver, and automatic Keplerian element updating. Also WXtoImg displays APT weather images as they are being received, which gives an illusion of actually flying with the NOAA spacecraft and looking down on Earth; quite exciting stuff for a school kid (and big kids!). Any basic Pentium computer, combined with Jim’s receiver and antenna and running WXtoImg would make a very slick little educational or home receiving system. A well-featured version of WXtoImg may be downloaded as freeware from http://www.wxtoimg. com/ Andre Phillips, VK2AAP/ZL3AW, Coonabarabran, NSW. Dual supplies not a big factor in amplifier performance I rather liked the concept of the dual power supply in the Ultra-LD amplifier design (SILICON CHIP, March & May 2000, November & December 2001, January 2002). That is, having a separate regulated supply for the frontend voltage gain stages and a conventional high power/current supply for the driver and output stages. I imagine that this configuration results in near perfect CMRR figures which remain constant even at loud levels. I would like to know how much this contributes to the high performance specs of this amplifier – and if this could be adapted to other designs on the basis that this would improve the specs of these also; including the SC480 and now the Studio 350? Do you think that there would be any advantage in doing this? Grant Saxton, Cambridge, New Zealand. Comment: while the separate power supplies do offer a useful improvement in performance, it is not a major factor. Where they do help is in providing a higher signal voltage from the driver stages before the amplifier runs into clipping. This is why the Ultra-LD has such an abrupt transition from low distortion into clipping, as compared with the more gentle transition with the SC480 and Studio 350 designs. By far the most important factor in the low distortion of the latter two amplifiers has been the PC board layout. We now think that if we applied the same PC board strategy to the Ultra-LD, the performance would be even better. Would the separate power supply rails produce a big improvement in the SC480 and Studio 350? Probably not. Human-power LED torch variant needs no rectifier Here is an idea for another variant of the human-powered LED torch presented in the February 2004 issue. During my initial testing of this great idea, I found that unless the stepper motor was turning fast enough, nothing happened. This is due, I believe, to having to overcome the forward bias voltage drop of two diodes (1.2V). It occurred to me that this is a waste of output, so two pairs of LEDs were connected directly to the motor as inverse-paralleled pairs. The result of this is quite dramatic. The slightest turn of the shaft produces very bright, although flickering light. Of course, the flickering smooths out if you turn fast enough. The motors we initially used are quite small; with large ones, the output is awesome! This application would be ideal for installation on bicycles, etc, since the objective is maximum light for minimum weight. The fact that there is always one LED conducting prevents any possibility of excessive reverse bias, although I have not measured the no-load output. Also, there appears to be a different output sequence depending on the rotational direction. Plugging the LEDs into the connecsiliconchip.com.au tor on the motor cable, in a square arrangement of inverse-parallel pairs, the sequence is diagonally opposite pairs flash together while in the opposite direction, adjacent pairs flash. I have observed this with two different motors. There are probably applications for this such as directional sensing. Geoff Hahn, via email. Of valves and brakes Thank you for the article on antilock braking in the February 2004 issue. I recently did an advanced driver’s course and most of the cars had ABS. Mine didn’t. At the start of the day I was able to out-brake and out-corner most of those using ABS. Sure it doesn’t take much to learn the basics, and once they were shown the importance of seating position and brake pedal use, they outmanoeuvred me with little problem. But it does raise the question of how many people receive the correct instruction in ABS use at the time of purchase. I love the arguments about valves. I do not own a valve amplifier. I tried a few under the $5000 mark but they did not set me alight, however my CD player does have a valve output stage. Specifications can be misleading and lots of preceding zeros in the distortion figures are not necessarily an indication of sound dynamics. I sold a well-known transistor based amplifier with distortion figures of around .002% at 170W and replaced it with a 70W amplifier with distortion of 0.12%. Yet there is a vast difference in what my ears hear. AND shock horror, it has zero negative feedback. Andy Lee, Motueka, New Zealand. Comment: it is safe to say that, in Australia at least, no-one is instructed about a car’s features at purchase and certainly not the best way to use the ABS. Exciting time for DIY loudspeakers Now is an exciting time for do-ityourself loudspeaker construction as many important developments and notable names exist now. For decades the weakest part of the hifi system has been the loudspeaker. By the early siliconchip.com.au 1980s sealed and especially ported manufactured loudspeakers have been accurately and scientifically designed using parameters from the work of Thiele & Small. In addition to properly designed boxes, current drivers can be really quite good and need not easily be the weakest link. For example, Seas Excel range of mid/woofers offer a claimed THD of 0.1-0.3%, a remarkable and also figure (see www.seas.no). It is an exciting era as information can be directly and personally retrieved from the internet. One outstanding source from the web, for example, the DIY Loudspeaker Designer’s Selection Guide (LDSG) lists all recommended drivers (see http:// ldsg.snippets.org), as well as web retailers such as (www.madisound.com) and (www.e-speakers.com). For excellent value for Peerless or Vifa drivers and cheaper varieties one can’t go past the Australian (www. wescomponents.com). E-speakers and LDSG are good to refer to ribbon tweeters, another exciting development due to cheaper production of rare earth magnets and fidelity demands of DVD-audio and SA-CD. Philips now market a consumer DVD surround system featuring their own leaf ribbon tweeters. The web also allows downloading of great freeware to design boxes to one’s desire using Thiele-Small parameters (eg, see winISDbeta on www.linearteam.dk). For ease in building speaker cabinets there are hardware items like the very useful Jasper Jig for routing perfectly round holes and recesses (see soundlabsgroup.com.au/jasperaudio/ index.htm). I recommend buying a router with exchangeable 1/4 and 1/2inch chucks, and perusing a router bit catalog (see www.carbitool.com.au). The hobbyist’s effort in either building a budget or a world-class speaker system is practically the same, as is the cost of tools used and the timber which will more often than not be MDF. By spending hundreds, the hobbyist can build something of only better value than something in the shop. By spending a few thousand, however, the hobbyist can build a world-class system, giving many years of fine listening, and giving a system that would be 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 progamming 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 June 2004  5 Mailbag: continued many times more expensive if sourced commercially. Sadly, this second choice has not been an option from the offerings of electronic magazines. This is a pity. One aspect of speaker building which has not been covered, is the crossover. These are quite tricky for the novice to design and the quality of the passive components in the crossover can be detrimental to the sound, especially for modern high definition drivers and amplifiers, etc. This problem can be completely sidestepped by using active cross­ overs and multiple amplifiers customdesigned for each speaker box. This will actually give the greatest sound quality and is perfectly matched for the realm of electronic enthusiasts. However, active systems dictate an expensive project not suited for budget drivers. Thus a complete feature for an active system, using the classiest drivers has not been featured in magazines, which have robbed enthusiasts of a class project, despite the classiest amplifier modules and active cross­ overs being published. Perhaps the latest & greatest exciting development is a resonant free speaker frame which is boxless and (necessarily) active to give the highest available fidelity without outrageous costs – a perfect project for the electronic audiophile enthusiast (see www.linkwitzlab.com). The credentials for such a design comes ironically from one of the developers of commonly used passive crossover design theory. I predict that this active open-baffle system could be, or should be, the future for home audiophile enthusiasts with electronic skills. Would it be suitable for SILICON CHIP to bring together past articles with fine drivers (eg, Seas) for a fully-featured active speaker system and also perhaps flirt with a Linkwitz-style active openbaffle non-resonant system? Paul R. Rohde, via email. Comment: the major reason why do-it-yourself speaker systems with such elevated prices have not been described is that they are far beyond the budgets of most readers. 6  Silicon Chip Making PC boards with transparency film I use a different technique to that described in your April 2004 issue on circuit board preparation and this yields much better precision then the “iron on” method. I use a 600 dpi laser printer together with Hewlett Packard LaserJet monochrome transparency film (available from the larger stationery suppliers like OfficeWorks). When I set up the printer out of Autotrax, I use the “mirror” setting which puts the image on the film in reverse – this will be explained later. I also use the pre-coated positive-acting laminate from Kalex together with their liquid developer. This system, although photographic, can be used in subdued light, so there is no need for a darkroom. When the transparency is ready, the protective membrane is peeled off the circuit board and the transparency is then laid face down (image towards the board) on the pre-sensitised surface of the board. With the image printed in reverse, the image will now appear “right way around” on the board. The board is then exposed through the film in a light frame (with four 20W UV fluorescent tubes) for about 90 seconds. This time will need to be determined experimentally using scraps of circuit board and depends on the light frame configuration. Once exposed, the transparency is separated from the board and the board then developed in the solution supplied by Kalex. When the image is fully developed, the board is washed off in hot water and then etched as in your article. I prefer to use ammonium persulphate (even though it must be heated) because I find the ammonium much cleaner and more pleasant to use – besides I get into far less trouble from “she who must be obeyed” about stains in the laundry and on my clothes! The image obtained by this method is very sharp and very well defined. I can use tracks down to 10 mil with confidence and making a double-sided board is basically just as easy. You just produce the two sets of artwork (both sides), carefully align them, lay them up together and slip the circuit board in between using adhesive tape to secure the board to the film so that it won’t move when you turn it over to expose the second side. The secret to this method is that you cannot use “just any old transparency film”; it has to be “good” (read, a little more expensive) and be capable of producing a good solid black image, such as the HP film. Once set up, I can produce a double-sided circuit board in about 10 minutes from printer to etched board and be confident about the finished product every time. Jeff Thomas, via email. Comment: we described this method in detail in March 2001, although we suggested that “... the density (of transparency film) isn’t quite good enough for PC board making”. Guess it is, if you have the right film & printer! EGO sensor as kiln monitor Pages 64-65 of the April 2004 issue have a truly excellent description of the operation of an EGO oxygen sensor. I am a potter with a science degree background and a long-time reader of SILICON CHIP. About 18 months ago, I spent time devising an instrument for measuring the degree of reduction or oxidation in the atmosphere of a gas-fired kiln, making use of an EGO sensor mounted at the kiln flue. This was written up as an article featured in the American pottery magazine “Ceramics Monthly”, in their March 2003 issue, under the name “Kiln Exhaust Sniffer”. This was later included in the “must read” pages of their website. The URL is http://www.ceramicsmonthly.org/ mustreads/sniffer.asp Disappointingly, in their editorial wisdom they didn’t include the graphs of EGO readings at various stages in a kiln firing, showing how the millivolt output from the salvaged EGO sensor ($5) compared with that from a commercial oxygen probe ($800) but the whole idea came out plainly enough. Roger Graham, Pottery at Old Toolijooa School, Toolijooa, NSW. Comment: The EGO description was part of the article entitled “A Smart Mixture Display For Your Car”. 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e take it pretty much for granted that almost 400 tonnes of 747-400 screaming along at the best part of 1000km/h manages to find and land at the right point on the right runway, every time . . . but how do they do it so well? Instrument Landing Systems. . . how they work I t was a drizzly, miserable day with a low, grey blanket of cloud, heavy and oppressive. Looking out the airport terminal window, the world seemed to end barely a kilometre away. Vague silhouettes of aircraft moved silently about in the misty rain. I looked up at the arrivals screen to check my friend’s flight from Perth. It had already arrived, five minutes early, of course! Best get to the gate quickly . . . As I walked to the arrivals gate I reflected on what I had just taken for granted. Just a few minutes ago, my friend’s plane had been hurtling towards the ground at 250km/hr with nothing but solid murky grey out all of the windows – including those of the cockpit. In fact, the plane may have descended to as low as sixty metres above runway height with little, perhaps no, outside visibility. We expect planes to land in all 8  Silicon Chip sorts of weather. In Europe and North America, a pilot can land an aeroplane on some runways without seeing the ground at all. Automatic landing and taxying systems are continually becoming more capable. Today it is technically possible to safely and reliably land, slow down and taxi to the correct gate with no outside visibility and hardly any human intervention. tral challenge is navigation. In this article we will look at the Instrument Landing System (ILS), which still provides precision landing guidance 65 years after its invention. We will also see the impact of newer technologies such as GPS, Microwave Landing Systems and ever-increasing on-board digital processing power. But first, some background. The issue is guidance Most readers would be familiar with basic radio direction finding using a loop antenna. You rotate the loop until you find a “null” in the signal. If you point with your hand straight through the loop, you are pointing either directly towards or directly away from the transmitter. Direction finding is the basis of radio navigation. Instead of plotting a visual “fix” to a landmark on a chart, you plot a radio “fix” to a known transmitter. Radio navigation today is quite sophisticated, even before you include So how does all of this work? First, let’s keep in mind what we’re looking at. A modern aeroplane can fly equally well through clear day or foggy night. The challenge with all weather landings is to provide some form of guidance so that the pilot (or an autopilot) can stay lined up with the runway and descend on the correct path without actually seeing the runway. The cen- by Daniel Field Radio Navigation siliconchip.com.au Somewhat stylised diagram of a typical runway with ILS. Not shown here are the inner, middle and outer “markers”. A little trivia: one runway number subtracted from its opposite end number will aways equal 18! GPS. Apart from Instrument Landing Systems, three radio navigation systems have been central to aircraft navigation for several decades. They are: 1. ADF (Automatic Direction Finder). Gives the bearing (direction) to the transmitter relative to the nose of your aircraft. Combined with “magnetic heading” information from the aircraft compass system, it gives the magnetic bearing to the transmitter. 2. VOR (VHF Omnidirectional Range). Tells you what your bearing is from the transmitter, no matter which way you are pointed at the time. These fixed lines of bearing from the transmitter are called “radials” and are commonly followed as “roadways in the sky”. 3. DME (Distance Measuring Equipment). Uses pulse timing techniques to tell your distance in a straight line from the ground equipment. It is usual to co-locate DME and VOR ground equipment to provide range and bearing from the same location. Pilots use these systems to find their position over the Earth’s surface without any visual references. None of them can determine height above the ground: they are all lateral navigation (LNAV) techniques. The problem of landing and approach Using lateral navigation techniques an aircraft can fly clear of obstacles and line up with a runway. This procedure is called a “Non Precision Approach” (NPA). During an NPA the pilot uses an altimeter (which is based on air pressure) for height information. For a variety of reasons, pressure altimeters can theoretically be inaccurate by up to 100 feet (30 metres). So a published NPA must allow plenty of margin for error if pilots of varying skill levels in a wide variety of aircraft are to follow it thousands of times per year. A typical NPA in an area clear of obstacles can get the aircraft down to about 400 feet (120 metres) above the ground. If the pilot cannot clearly see the runway then he can safely “go around” – pulling out of the landing approach and flying in a predetermined pattern to return to the approach path and again line up with the runway. Therefore, without some form of precise vertical guidance, an aeroplane cannot land unless the cloud base is at least 400 feet above the ground. The Instrument Landing System (ILS) As early as 1928 (which, by the way, is only a year after Lindbergh first crossed the Atlantic), engineers and scientists were giving careful attention to the problem of vertical guidance for landing. Teams in different countries developed various solutions. By 1940 a working “Instrument Landing System” had been installed at Indianapolis airport in the United States. The Instrument Landing System (ILS) was a new radio navigation system that provided precise vertical guidance (referred to as the “Glide The heart of the ILS system: at one end of the runway (far end from approach) is the antenna system for the “localiser” beam. This gives the aircraft its left and right guidance signals to help it line up with the runway. Alongside the runway, roughly at the touchdown point (ie the approach end), is the guideslope (or glidepath) antenna which helps the aircraft approach the runway at the right angle and hit the tarmac at the right place. siliconchip.com.au June 2004  9 Path” or “Glide Slope”) as well as precise lateral guidance (referred to as the “Localiser”). Both the glide slope and the localiser worked on the same technique: a radio technique that is still in use today at thousands of ILS-equipped runways around the world. The glide slope carrier signal is in the range of 329-335MHz. The localiser carrier is in the range of 108-112MHz. The glide slope and localizer carriers are each directional radio beams radiated in two parts: one amplitude modulated at 90 Hz, and the other at 150Hz. In the case of the glide slope, a directional antenna array radiates the 90Hz signal just above the correct approach path and the 150Hz signal below it. Right on the approach path, the modulation of both components is 40%. An aircraft anywhere along the correct glide path will receive both the 90Hz and 150Hz components equally. If the aircraft moves above the correct path it moves toward the centre of the 90Hz beam and away from the 150Hz beam. Because they are both on the same carrier, the detected depth of modulation of the two signals is no longer equal. The 90Hz signal will seem to have deeper modulation than the 150Hz signal. While every glide path is adapted for each particular airport, a typical path is at an angle of about 2.5 to 3°. The aircraft’s receiver detects the 90Hz and 150Hz components then separates them using a simple filter network. The two components are full-wave rectified to produce two DC signals: one representing the strength Pilot’s-eye-view of a 747-400, lined up on runway 34R at Sydney International Airport. This amazingly realistic view is actually taken from Microsoft Flight Simulator IV, which we’ll have more to say about shortly . . . of the 90Hz component, and the other the 150Hz. The difference between these DC signals drives a moving coil meter. If the 90 and 150Hz components are equal then there is no difference, so the meter stays in its “at rest” position in the centre of the indicator. If the 90Hz component is stronger, the meter drives down to indicate “fly down”. A deviation of half a degree above or below the glide path gives full-scale deflection of the meter. This corresponds to a difference in depth of modulation (ddm) of 0.175, or 17.5%. In the case of the localiser, a directional antenna array transmits the 90 Hz signal to the left of the runway cen- tre line (from the point of view of the approaching aircraft), and the 150Hz signal to the right. The modulation of both signals is 20% on the correct path. Again, the receiver rectifies the two components and drives a meter movement. Full-scale deflection indicates about three degrees deviation from the centre line, with a ddm of 0.155. How far to go? Assuming that the pilot has no outside visual cues, the Instrument Landing System that I have described still relies heavily on the altimeter. Sure, the pilot knows that he is approaching the runway on the correct path. The beam pattern set up by the glideslope (or glidepath) radio signals. It really is quite simple – fly too high and the 90Hz signal is received; fly below it and the 150Hz signal is received. 10  Silicon Chip siliconchip.com.au Again from Flight Simulator IV, compare the clean, modern instrumentation of the 747-400 to the instrument panel of a Beechcraft King Air, here lined up on runway 29C at Bankstown airport, Sydney (incidentally, the busiest airport in Australia for aircraft movements). But what is to stop him from staying nicely on path until he crashes into the runway? The fact that he crashed right on the touch down point is unlikely to be much consolation. The designers of the Instrument Landing System decided to place various “Markers” along the approach path so that the pilot knows what stage of the approach he is up to. These markers are low power transmitters that radiate in a narrow beam straight up. The carrier is always 75MHz. The AM signal depends on the function of the marker. On a normal instrument approach, the pilot initially uses his altimeter to fly at a particular altitude (say, 2,500 feet above the ground) and various radio navigation aids to intercept the Localiser. The aircraft then flies along the localiser toward the runway, maintaining a particular altitude (using the altimeter). As the aircraft flies along, it is actually below the plane of the glide slope. If you were in the cockpit, you could say that the glide slope is in front of you, slanting down toward the runway, and you are flying level towards it. Imagine for a minute how this works in the cockpit: As the aircraft moves into the lower part of the glide slope signal the indicator shows “fly up”. The pilot continues to hold the same altitude. The glide slope indicator starts to show that the aircraft is coming up to the centre of the glide path. The pilot then initiates a descent to capture the glide slope. As long as the aircraft stays on the glide path, it is safe to descend. This is where the designers used the first marker: The Outer Marker. Right at the point where the pilot should intercept the glide slope the aircraft flies through the outer marker beam. The pilot hears a 400Hz tone (a moderately low pitch) which also causes a blue indicator light to illuminate in the cockpit. The tone and light make a continuous stream of Morse code “dashes” at the slow rate of two dashes per second. If a pilot passes the outer marker and still does not have a glide slope signal then he knows that there is a problem. Australian approaches actually use the Outer Marker at some point along the descent rather than at the glide slope intercept. The intercept point may be directly over some other radio beacon that does not normally form part of an ILS. Sometimes it is not marked at all but can be anticipated a certain distance from the airport using radio distance measuring equipment. Whether or not the outer marker coincides with the glide slope intercept, it is an important indication of the aircraft’s progress along the ILS. The next marker is the “Middle Marker”. This is usually about a kilometre from the runway. The pilot hears alternate dots and dashes at 1300Hz, illuminating an amber light in the cockpit. The middle marker normally And here’s the way the middle and outer markers are set up. They are very narrow beams which are received in a very specific location, telling the pilot the plane has passed through the marker. siliconchip.com.au June 2004  11 indicates that the aircraft is 200 feet (60 metres) above the ground. On basic Instrument Landing Systems (including most systems currently in use around Australia), 200 feet is the “decision height”. The pilot may continue to descend beyond the middle marker only if he sees the runway. Once again, there is some variation from one approach to another. For example, there is no middle marker at Nowra, NSW. The pilot must use DME to determine decision height (at a distance of 0.8 nautical miles from the runway). Perth’s ILS runway 03 has no markers at all. Three of Sydney’s six ILS approaches also have no marker beacons (because of possible confusion with markers for parallel runways). They all use DME distances instead. On more advanced instrument landing systems the decision height can be either 100 feet or zero feet. Those systems can include an “Inner Marker” which gives the sound of rapid dots at 3kHz (high pitch) and causes a white light to flash in the cockpit. The inner marker normally indicates a height of 100 feet above the ground. Note that at this point, the aircraft altimeter could possibly indicate anything from zero to 200 feet above the ground (though, in 12  Silicon Chip siliconchip.com.au reality, almost all altimeters in instrument rated aircraft are likely to be within ten feet of the actual altitude). Three levels of accuracy Instrument Landing Systems are theoretically capable of guiding an aircraft all the way to the ground. But the very high accuracy and reliability required for this task comes at a cost. Installations that can guide an aircraft right down to the ground must be tested and proven over a period of years, then continually monitored, tested and maintained to exacting standards. There is also a paradox that causes more accurate systems to be less capable than less accurate systems: as an aircraft travels through the directional localiser and glide slope beams, it warps them. The signals received by a following aircraft might not be accurate. The most precise instrument landing systems depend on much larger spaces between approaching aircraft than the less precise systems. As a result, less precise systems can handle more than double the number of landings per hour. None of the systems installed in Australia can guide an aircraft all the way to the ground. The majority are “Category One” Instrument Landing Systems (ILS Cat I), with a decision height of 200 feet. A runway will only be open for Cat I approaches if the “Runway Visual Range” is at least 800 metres. The next level of precision is a Category two ILS. In a Cat II system the decision height and visibility (“Runway Visual Range”) requirements are half those of Cat I. That is a decision height of 100 feet and a visibility of 400 metres. Category three systems are installed primarily in North America and Europe. For example, there are 31 Cat III systems installed at 15 airports in Germany. Nearly all of these are “Cat IIIB” (see table). Europe is currently moving away from Instrument Landing Systems in favour of the more capable “Microwave Landing Systems” (MLS). Improving the system The basic ILS with moving coil meters is still used to-day in some private aircraft, older charter planes, and many instrument-training planes. But these systems are practically obsolete. Modern business aircraft and airliners only use mechanical instruments as back-ups, if at all. LCD screens, modular digital computers and data-links are standard fare in today’s new aircraft. Autopilot coupling One of the first refinements of the basic Instrument Landing System was autopilot coupling. A traditional ILS receiver puts out a DC analogue signal that drives a meter movement. If you think of the signal as a command to “fly up/fly down” or “fly left/fly right” then you can use it as an input to an autopilot. The human pilot may manually select “ILS” mode siliconchip.com.au June 2004  13 HF Radio Antenna “NAV” Antenna “NAV” Antenna Above: typical “rabbit ears” VOR/ILS antenna near on the fin of a Piper Navajo Chieftain, with the longer wire HF antenna at top. The ILS receiver normally has separate transmission line inputs, one for LOC (~110MHz) and one for GS (~330MHz). Some aircraft have a separate GS antenna (typically dipole, mounted inside the nose), while many have just one antenna with a splitter. Right: a more aerodynamic nav antenna used on aircraft above about 250km/h. on the autopilot, telling the autopilot to follow the ILS output commands. Future displays Several companies are experimenting with new ways to display ILS information. One major source of inspiration is the video game industry. Current prototypes display a 3D graphic of the actual surrounding landforms and hazards such as masts and towers. The colours on the display indicate potential hazard, from red (land at or above the level of the aircraft) through yellow to green (land far below). Contours are shaded to give an easy to interpret depiction of the actual surrounding area. The display is based on a computer model of the actual terrain (yes, every aircraft might carry a detailed digital model of the entire world in the near future). Developers and promoters of these systems often call them “Synthetic Vision Systems”. During a landing in cloudy or foggy Aircraft and video games designers might seem to be strange bedfellows but they have a lot in common. One tries to make games simulate the real thing as much as possible, the other is incorporating much of the graphics of the games into the real thing, as this “Synthetic Vision” screen grab shows. 14  Silicon Chip conditions, a Synthetic Vision System can display the surrounding area as if it was a clear day. With suitable overlays (such as markers showing the correct approach path, and an aeroplane graphic displaying pitch and roll attitude as well as actual position), an approach and landing in poor weather could become very much like a computer game. On-board digital processing power The rise and rise of digital technology has hugely impacted the field of aircraft avionics. One of the first tasks given to digital processors was to process flight and navigation data using algorithms designed to make the most efficient use of resources. In the area of navigation, this meant keeping the aircraft right on the most direct track, and manoeuvring through standard terminal approach routes as accurately as possible. It wasn’t long before manufacturers started to integrate avionics systems that had previously been independent. As technology developed through to the late 80s, various researchers experimented with the idea of having one central navigation computer. By the mid 90s, the World’s major avionics producers all offered some variation on a central navigation and performance computer: the “Flight Management System” (FMS). Today, practically all new jets and an increassiliconchip.com.au Microwave Landing Systems Europe is moving rapidly away from the Instrument Landing System in favour of its newer rival, the Microwave Landing System (MLS). MLS is not simply an ILS using different carrier frequencies; in fact the operating principles of MLS are completely different. The purpose, though, is the same: to give precise lateral and vertical guidance, as well as distance from the runway. The basic technique used in the Microwave Landing System is a “Time Referenced Scanning Beam”. Without going into too much detail, MLS transmits a narrow beam at around 5GHz that sweeps across the approach area in a set pattern. The aircraft receiver measures the time intervals between sweeps and calculates its lateral position (azimuth) and vertical position (elevation). The “to and fro” azimuth and “up and down” elevation beams both occupy the same carrier frequency, although they are transmitted from two different antenna arrays located similarly to an ILS. The third, essential component of MLS is a precision DME (distance measuring equipment) which gives range accurate to within 30 metres (compared to 360 metres for regular DME). MLS also transmits data to the aircraft by modulating the azimuth signal. Data can include information about the approach, weather, runway condition, etc. There are several advantages of MLS over ILS. Perhaps the greatest advantage is its flexibility – ILS has only one correct path (where the difference in depth of modulation is zero), so its output must always be an error signal: “fly right”, “fly up”, etc. MLS is designed to tell the receiver its precise angle from the runway centre line (to about 40° either side) its elevation above the horizon, as seen from the touch down point (to about 15° up), and range from the runway. The receiver’s output is a position rather than an error. The MLS computer in an aircraft can be programmed with a desired approach path and then guide the pilot or autopilot along that path, comparing the actual position with the desired position to give the standard “fly right”, “fly up” signals. That means that the one MLS installation can precisely guide many different approaches at any glide path angle as well as manoeuvres such as dog-legs or curves around obstacles out to a distance of about 35km. It is reasonable to expect that MLS will completely replace ILS in Europe by about 2020, with only a few ILS installations surviving beyond 2015. The UK has purchased over 40 MLS installations (including options) over the past year alone. However, the rest of the World is likely to stick with ILS for several decades more. ing number of propeller planes come with a Flight Management System as part of an integrated, modular digital system. While different levels of integration are available, a fully functional FMS will have inputs from all of the on-board navigation and flight data systems and outputs to the autopilot computers, digital engine control computers, and various cockpit displays. During an approach in low visibility conditions the FMS can handle many tasks like selecting the frequency on the ILS receiver, continually monitoring how well the aircraft is performing, and commanding the autopilot and engines so that the aircraft follows a pre-defined “Standard Terminal Approach Route” (that’s right: when an aircraft is within about 30km of its destination it is usually “following a STAR”). This centralisation of control and monitoring functions has allowed automation to move into the part of flight that uses practically every system on the aircraft: the approach and landing. system is not too hard to imagine. A computer selects the right navigation inputs and autopilot modes so that the aircraft follows the ILS. A radar altimeter input (giving actual height above the ground, potentially accurate to a few feet), a precision DME (as in a Microwave Landing System), or a suitably augmented GPS controls the timing of the “flare” (the deliberate loss of lift as the plane lands). Weight-on-wheels switches detect the actual landing, and the computer controls deployment of spoilers, reverse thrust and brakes as required to slow the aircraft. GPS combined with a database of the airport layout provides for the aircraft to automatically taxi to its gate. (This ignores taxi clearances and other aircraft – a data link from the airport surface move- ment controllers could provide the required information.) However, technical possibility is not the whole story: If planes full of people are to routinely “autoland” in all sorts of conditions then technically possible is not enough. A reasonable margin of safety must be a part of the system. When a plane is landing itself, the Autopilot system has control of the aircraft. All autoland-equipped aircraft must have a “triplex” autopilot. That means that there are actually three separate autopilot systems installed in the aircraft. There are various ways Automatic landing Technically, an automatic landing siliconchip.com.au This cockpit almost looks like a video game –but it’s not. It’s from the Eclipse Aviation E500, a new mini jet scheduled for release in 2006. June 2004  15 GPS and all-weather landings... “What about GPS?” I can hear you asking. “Doesn’t GPS make the whole instrument landing system obsolete?” The answer is a resounding “not really”. In Europe, ILS should be obsolete by 2015. But that is due to a rival system (Microwave Landing System), not GPS. Outside Europe, ILS will still be around for a few more decades. So why hasn’t GPS taken over the precision approach scene? Since selective availability was switched off isn’t the accuracy down to millimetres? There are several good reasons why aviation has not relied on GPS for precision approaches. The first is political: the U.S. Department of Defence owns and operates the GPS constellation. Five years ago when the Clinton administration announced that they would switch off selective availability, they reserved the right to switch it back on again at any time. Despite formal agreements between the US Dept of Defense and the US Federal Aviation Administration, there has always been a tacit understanding that civil aviation should never rely too heavily on GPS without extra in-built safety. There are other issues with GPS. Accuracy is excellent, but still variable. For just a few minutes per day in any location, the various random errors combine to significantly degrade the accuracy. In the big picture it is hardly significant. But it does mean that you cannot solely rely on GPS if you require very high precision on demand. Another issue is signal availability. The receiver needs at least five satellites to verify the integrity of its position solution. Along the south coast of Australia, for example, there may be fewer than five satellites in view for a total of around 30 minutes out of every 24 hours. Having said all of that, satellite navigation systems are continually improving. Several developments are making GPS more available and accurate. A European consortium is developing a rival system called “Galileo”, which 16  Silicon Chip will have the political advantage of civilian control. The International Civil Aviation Organisation, which sees all of the major Western countries jointly determining policies, has decided that satellite navigation systems will be the basis for future aeronautical navigation systems. So does GPS have a role in all weather landings? Well, yes, it definitely does but not by itself. GPS will be available for precision approaches once suitable methods of “Augmentation” have been developed and tested. One ground-based system, called “Local Area Augmentation System” (LAAS) is basically a GPS receiver fixed to a precisely surveyed point on the ground. A computer compares the actual, known location of the receiver with its “GPS location”. It instantly detects any error. The system then broadcasts information about the error over a data link to all aircraft within a radius of, say, 50 kilometres. If the LAAS site is located near an airport, an aircraft can make a precision approach using GPS data corrected by the LAAS data link. Australia is likely to adopt this system. In the United States a satellitebased “Wide Area Augmentation System” (WAAS) is under development. This is similar in principle to LAAS but on a different scale: In version one of the system there are 25 surveyed “Reference Stations” across the country and two “Master Stations”. The data link to aircraft is via communication satellites. The advantage of covering the entire country is offset by the necessary compromises in accuracy and integrity. As a result, WAAS will only be good for the equivalent of ILS Cat I approaches (Decision Height of 200 feet). Even that will only be under ideal conditions. This limitation ensures the continued use of ILS in North America, at least for a few more decades. Europe is set to adopt a combination of ground based augmentation and microwave landing systems, with the Galileo global navigation satellite system likely to take over from GPS for essentially political reasons. of making a triplex system work: Normally, all three work together. They each gather their data (such as airspeed, attitude, deviation from intended path, etc) and then “vote” on the action (for example, to roll left at a certain rate). As long as all three systems agree, the autopilot is working in its full triplex mode. International standards allow automatic landings only when the autopilot is working in triplex. If one of the three systems fails or produces an error, the aircraft can still fly under the command of the other two autopilots but the safety of the triplex voting system is lost. In that case, the pilot must abandon the automatic landing, but may continue with a regular instrument landing. Instead of having three complete autopilot systems, it is possible to have a “pseudo-triplex” system. A computer model that votes according to the aircraft’s expected movements replaces one of the three autopilot systems. Conclusion Every year around the world, aircraft of all sizes safely make millions of landings in conditions that make a visual landing impossible. The Instrument Landing System has provided precise guidance for landing in these conditions for over sixty years. According to some authorities, ILS is likely to be in use for another fifty years yet. But in aircraft systems, like so many other things, technology is continually advancing as individuals look for better ways and companies look for a competitive edge. Improvements in GPS-related technologies, new capabilities of Microwave Landing Systems, and the almost limitless memory and processing capabilities of digital computers are turning our heads toward the future. Stanley Kubrik’s film “2001, A Space Odyssey” may have proven to be a tad optimistic in its setting. But anyone from that sci-fi mad era transported to the flight deck of a modern airliner as it approaches and lands in cloud and fog would surely think that he could be in a space craft landing on another planet. A crew of two, calmly watching the large, clear, uncluttered displays and checking altitude and system parameters out aloud while the plane lands itself: surely this was the stuff of science fiction not so long ago. siliconchip.com.au Ever looked at an aircraft instrument panel? What are all those meters and things for? For the uninitiated (ie, non-pilots!) an aircraft instrument panel can be a pretty confusing place. To make matters worse, every aircraft is different. But once you recognise what each is for and what it does, it’s not so daunting after all. . . B A C D G E F H This is just a tiny section of what a pilot has to keep his/her eyes on. But apart from radio systems, these are arguably the most important instruments as far as the pilot is concerned. (A) Clock (yep, to tell the time) (B) Airspeed indicator – in knots (C) Attitude Indicator (the plane’s, not the pilots!) (D) Altimeter – how high you are above sea level (E) Turn Co-ordinator (also called “turn & bank” or “turn & slip” indicators). (F) Radio Magnetic Indicator – displays both magnetic and radio compass. (G) Horizontal Situation Indicator – shows the localiser beam (the vertical yellow line) and the glideslope (the two yellow triangles on the edges). That’s the one that this article is most concerned with! (H) Rate of Climb Indicator – tells you how fast you are going up or down. And here’s how the loc/glideslope indicator helps you land... If the receiver is not receiving a strong enough signal, or if the signal is not valid, then a red “NAV” flag on the indicator warns the pilot not to follow the indications. Having used other radio navigation aids for lateral guidance and the altimeter for height, the aircraft is now lined up with the runway centre line, about 25km from the runway. The localiser indicates “on localiser” but there is no glideslope signal yet, so the plane does not descend. Having maintained altitude and followed the LOC, the plane is approaching the GS intercept. There is now a GS signal, indicating that the plane is below the glide path (ie, a “fly up” indication). “Fly Down” half scale ~ 0.25° above glidepath (the two yellow indicators are below the horizontal reference). “Fly Right” one dot (on 5-dot scale) ~ 0.5° left of path (the vertical yellow line is to the right of the vertical reference). “Fly Up”, “Fly Left” “Fly Down”, On LOC Continuing to hold the same altitude and follwing the localiser, the plane is now only about 0.2° below the glide path. The pilot (or autopilot) will start initiating a descent soon. “Fly Up”, On LOC The plane descends along the ILS and simply follows any “fly up”, “fly down”, “left” or “right” indications. By doing so it is flying precisely along the correct approach path. On glidepath, On LOC SC siliconchip.com.au June 2004  17 A quick look at: Microsoft Flight Simulator 2004 – A Century of Flight W hile we were preparing the Instrument Landing Systems article for publication, we were reminded that Microsoft Flight Simulator also caters for Instrument Landings – and is probably the closest thing that many readers would ever come to taking control of an aeroplane. We’d heard that you could “almost” learn to fly a real plane by first learning how to “fly” MFS. There were many news reports not too long after September 11 which stated the terrorists first learnt to fly using MFS. And we’ve seen other reports claiming MFS is not only used in flying schools but is also used by pilots to maintain their skill levels or to learn new skills without spending the sometimes huge amounts of money required to hire a real aircraft. Is that true? And what about the Instrument Landing System? How does that compare? With the quick co-operation of Microsoft, a copy of the latest version of MFS was soon installed in my computer and I went flying. Well, sorta flying. Taking off and crashing would be a more honest description (honest, boss, it was all for research . . .) Microsoft Flight Simulator has been around for twenty years. Somewhere in my software library there’s a copy of the first MFS. I remember thinking at the time that it was a very good simulation, particularly given the standard of computer graphics at the time. I also remember getting pretty frustrated at the time, taking off and crashing (yeah, nothing’s changed). I confess I haven’t looked at MFS in the ensuing two decades. So just how good is the latest incarnation of Microsoft Flight Simulator? (While it’s called MFS 2004, it was released in 2003 to mark the centenary of the Wright Brother’s first flight). In so many ways, it’s very, very good. The graphics, for example, are amazing. Being the parochial type, the first thing I did was load Sydney International Airport instead of one of the Seattle airports (OK, Microsoft designers are allowed to be parochial too!). For a couple of minutes, I thought that Sydney airport wasn’t included – but of course it’s there under its fair-dinkum name, Kingsford Smith International. Incidentally, you can choose 368 airports from Australia or 23,760 fields around the world. Want to fly out of Oshkosh? No problem, b’gosh! 18  Silicon Chip But back to Sydney. I took off (any idiot can take off – all you have to do is apply power and pull the nose up) and banked right. Sure enough, there was the Sydney CBD and Centrepoint tower. I buzzed the city at an impossible illegal height and even flew under the coat-hanger (Harbour Bridge for the geographically challenged). The scenery is amazingly realistic, especially from a reasonable height. “OK”, I thought, “I’m gonna find my house.” Completely ignoring air traffic control rules, I climbed to a thousand feet, followed the harbour down to the heads (well, something like the heads) and turned left up the Northern Beaches. Long Reef is a pretty prominent headland and just happens to mark the edge of controlled air space (I know that because Dick Smith told me that as we flew into Sydney one time). There, on its left, was the “lump” of Collaroy Plateau and immediately beyond Narrabeen Lakes. My place should be pretty easy to spot, between the two. But it’s not there – a high-rise building is. And it was a similar story all the way up to Pittwater and Palm Beach. So while the overall scenery is very good, it’s best viewed from a reasonable height and not taken too literally! Time to get back on terra firma. And here is where the terra started! I decided to head for Bankstown airport because I’d flown in and out of there recently. Let’s say my attempts to land were not quite as successful as take-off (remember I said any idiot can take off). But eventually, I did manage to put it down at Bankstown. Not necessarily on the runway – on any runway – but hey, a landing’s a landing! Flying lessons With a couple of weeks to spare, I would be able to perfect this because one of the most powerful features of MFS is its renowned inbuilt flying lessons. The introductory lessons, by King Schools, are a bit folksy American for me (sorry, John and Martha). The “real” lessons, by very experienced instructor Rod Machado are very good (but the jokes are corny!). You can advance from student, private, instrument, commercial and airline pilot, flying everything from a Cessna Skyhawk SP 172 right up to a Boeing 737-400. But that’s not all you can fly in MFS 2004. It’s not called “A Century of Flight” for nothing. You can fly everything from the 1903 Wright Flyer, through the Curtis “Jenny” (the barnstormer’s favourite), the Vickers Vimy, Lindbergh’s Spirit of St Louis, then through many of the world’s famous aircraft – DC3, various Cessnas, Beechcraft, Lear Jet, right up to Boeing 747 and 777. There’s also a couple of helicopters and even a sailplane – 24 aircraft in all. As you may have deduced, I am no aviator (it was always on my wish list but never got off it!). But I really do siliconchip.com.au believe that given enough time and practice, you could actually learn to fly using these lessons. Well, you’d certainly be a lot more capable of handling the real thing than a novice without any MFS experience. ILS Now for the reason we wanted to look at MFS in the first place: Instrument Landing Systems. Exactly as Daniel Field explained in the ILS article, you can use the glideslope and localiser needles to put your-self on the runway at the right place. It really is that easy. One of the MFS lessons covers this specific item. But there’s much more. MFS includes every electronic aid to flying that is currently available to a “real” pilot. You can even program in weather (including real siliconchip.com.au weather conditions applicable to your local area in real time). The cloud effects included with this edition of MFS have earned it “rave reviews”. For the more adventurous, you can program in gear failure. Want to lose an engine on take-off? How about a lightning strike knocking out all avionics on a 747-400 at 500 feet on final in zero visibility? No pressure! What you need The computer needs to have a bit of grunt. Minimum spec is a 450MHz processor with an 8MB video card and 1.8GB of hard disk space but we’d suggest this is an absolute minimum. Even on a 2.4GHz/32MB machine we noticed a few glitches. Most important, though, you need a joystick. They say you can use Review by Ross Tester MFS with the keyboard but it’s very frustrating. We actually bought a new joystick specifically for MFS. For less than fifty dollars you should be able to get a quality joystick with plenty of controls and, importantly, a throttle. These days, with USB on pretty well every computer, it’s sensible to get a USB joystick. Microsoft Flight Simulator 2004 – A Century of Flight comes on four CDs. One of the frustrating things is that, even with the program (all 2GB of it) loaded on your hard disk you still need to leave No 4 CD in the drive. It’s probably an anti-piracy device but it’s a pain in the proverbial. With a “G” rating, Microsoft Flight Simulator 2004 is available practically anywhere. Recommended retail price is $109.95. SC June 2004  19 N EW N EW June 2004 3m Tape Measure Magnetic end-hook for convenient measuring, anti-slip and shockproof rubber case. T 1210 2 $ 98 NETWORK Cable Tester N EW Identify cable faults such as incorrect connection, open, short, crossover and grounding test. 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Unfortunately, this prevents quite a few TV sets and projectors from displaying a steady picture during legitimate viewing. In particular, the extra pulses can cause problems with large-screen TVs that display the picture at 100 fields per second (100Hz) to reduce flicker, 24  Silicon Chip and also with projectors that perform line and pixel doubling to improve picture clarity. They can cause problems with older TV sets, too. If you have one of these sets or projectors, the only way to get a steady picture is to somehow remove these extra pulses. The idea is to “clean up” the video and let the set’s sync circuitry do its normal job without interference. And that’s exactly what the original Dr Video project described in the April 2001 issue of SILICON CHIP was designed to do. This improved version of Dr Video removes more of the copy protection pulses than the original design, for even more stable viewing. It also handles higher quality S-video signals, in addition to the normal composite video handled by the original stabi- liser. Finally, it also provides a wider video signal bandwidth, so your pictures won’t suffer any degradation. Dr Video Mk2 is housed in the same compact low-profile instrument box as its predecessor and runs from a 9V AC plugpack supply. As before, you should also be able to build it for considerably less than commercial stabilisers. How it works Before we look at the circuit diagram, it may help to explain a little about the copy protection pulses we’re trying to remove. We’ll be talking here about the pulses added to video signals in the Macrovision copy protection system, as this is the one most commonly used. To thwart illegal recording, the siliconchip.com.au Do the pictures on your TV set or video projector jitter and jump around when you’re trying to watch a video movie or DVD? If so, it’s probably caused by hidden Macrovision signals that are added to a lot of pre-recorded video software, to prevent illegal copying. Here’s an improved version of our very popular Dr Video stabiliser design, which cleans up the video even more thoroughly for stable viewing. It now also handles S-video as well as composite video. Macrovision system adds three main sets of pulses into the video signal – two of them essentially combined. First there’s the “dancing” pulses, which are added to as many as 14 of the normally black lines which follow the vertical sync pulse block, in the vertical blanking interval (VBI). This is a group of lines that correspond to the vertical retrace time, when the scanning electron beam in the picture tube is being returned from the bottom of the screen back to the top, to begin the next video field. To each of these 14 or so VBI lines, the Macrovision system adds as many as seven extra fake horizontal sync pulses, each of which is immediately followed by a short fake video bar pulse – which can have an amplitude anywhere between black and peak siliconchip.com.au white. It’s these fake video bar pulses which slowly vary up and down in amplitude (or “dance”), usually in two or three groups. The top traces in Fig.1(a) & Fig.1(b) show the basic idea. Fig.1(a) shows the Macrovision signal “dancing” pulses that are added following the vertical sync block. These pulses are constantly changing in amplitude. Similarly, Fig.1(b) shows the dancing pulses following the colour burst signal. Note that the lower trace shows these pulses completely deleted. In theory, these VBI pulses shouldn’t upset the operation of the sync separator circuit in a TV or projector – but they are intended to play havoc with the sync locking servo and recording level AGC circuitry of a video recorder. In particular, the extra sync pulses should muck up the sync locking, while the dancing video bars should fool the recorder’s AGC circuitry into Where To Buy The Parts Jaycar Electronics has sponsored the development of this design and they own the design copyright. A full kit of parts will be available from Jaycar, Cat. KC-5390. This kit includes a plated-through, solder-masked PC board; all on-board parts; a case with pre-punched front and rear panels with screened lettering; and a 9V AC plugpack supply. June 2004  25 Parts List 1 PC board, code 02106041, 117 x 102mm (double-sided – see text) 1 low-profile plastic instrument case, 141 x 111 x 35mm 2 RCA sockets, 90° PC mounting (CON1,3) 2 4 pin mini-DIN sockets, PC mounting (CON2,4) 1 2.5mm LV power connector, 90° PC mounting (CON5) 2 M3 x 10mm machine screws, with M3 nuts 4 small self-tapping screws, 6mm long 1 100µH RF inductor (RFC1) Semiconductors 2 MAX4451ESA dual video op amps (IC1,IC10) 1 74HC4066 quad analog switch (IC2) 3 74HC00 quad NAND gates (IC3,IC6,IC9) 1 LM1881 sync separator (IC4) 1 74HC14 hex Schmitt inverter (IC5) 1 4040B 12-stage counter (IC7) 1 74HC138 decoder (IC8) 1 7805 +5V regulator (REG1) 1 7905 -5V regulator (REG2) 1 3mm LED, green (LED1) 5 1N4148 signal diodes (D1-D5) 2 1N4004 power diodes (D6,D7) Capacitors 2 2200µF 16V RB electrolytic 2 100µF 10V RB electrolytic 2 2.2µF TAG tantalum 1 220nF MKT polyester 2 100nF MKT polyester 11 100nF multilayer monolithic 1 12nF MKT polyester 1 8.2nF MKT polyester 1 680pF disc ceramic 1 470pF disc ceramic 1 390pF disc ceramic 1 270pF disc ceramic 1 220pF disc ceramic 2 47pF NPO ceramic Resistors (0.25W, 1%) 1 680kΩ 4 510Ω 1 100kΩ 1 470Ω 1 82kΩ 3 100Ω 2 10kΩ 4 75Ω 2 2.2kΩ 2 24Ω 26  Silicon Chip varying the recording gain up and down. All of which they indeed do – but unfortunately the havoc isn’t just restricted to VCRs! EOF pulses The remaining set of pulses that are added into the video signals are the so-called “EOF” or end-of-field pulses. These are a set of narrow positive pulses added to the start of about six lines at the very bottom of the picture and timed to coincide with the colour synchronising bursts (ie, immediately after the horizontal sync pulses). In effect, these pulses push the colour bursts for these lines right up into the peak white region, so the black level and colour locking circuits of a VCR are again tricked. Fig.1(c) and Fig.1(d) show what the EOF pulses look like on an oscilloscope. The EOF pulses are harder to remove than the fake sync and dancingvideo-bar pulses in the VBI group. In fact, we didn’t even try to remove them with the original Dr Video project. However we have now worked out a way to remove them, so this new version of the project removes them as well as the VBI pulses. This should provide even more stable viewing. Now let’s see how it’s done. Circuit description Refer now to Fig.3 for the circuit details. It’s fairly straightforward and is based on 10 low-cost ICs. As shown, the incoming video signal is fed to either input socket CON1 (composite video) or CON2 (Svideo), with the S-video luminance component (Y) then going from pin 3 of CON2 to CON1. The chrominance (C) signal on pin 4 of the S-video socket is then terminated with a 75Ω resistor to give the correct loading, as is the luminance/composite video signal on CON1. From there, the S-video signals are fed into the non-inverting inputs of IC1a and IC1b, the two wideband op amps inside a MAX4451ESA dual video amplifier IC. Note that although the S-video chrominance (C) signal isn’t actually processed by the “filtering” circuitry of the stabiliser (it doesn’t need this), it must be passed through a matching amplifier stage to ensure it stays in phase with the luminance (Y) signal. Alternatively, if the input signal is composite video, it is simply fed to the input of IC1a and IC1b plays no active role; ie, there is no separate chrominance signal). Both IC1a and IC1b are connected as voltage followers with a gain of one, so replicas of the incoming signals appear at their outputs (pins 1 & 7). We’ll ignore the chrominance (C) signal for the time being, because it is simply fed to an output buffer amplifier (IC10b) without any changes. Instead, we’ll concentrate on the composite/Y signal, which is now fed in three different directions from pin 1 of IC1a. First, the video signal is fed via a 100Ω resistor and series 100nF capacitor to the input of IC4, which is an LM1881 sync separator. The 100Ω series resistor is included simply for decoupling, while the 100nF capacitor blocks the DC component. A 680kΩ and a 100nF capacitor from pin 6 of IC4 to ground set the chip’s internal timing circuitry for the most accurate and stable sync separation. The LM1881 provides a number of outputs but we only need three of them. From pin 1, we get a negativegoing composite sync signal, while from pin 3 we get similarly negativegoing vertical sync pulses (about 230µs wide). Finally, from pin 5, we get narrow pulses (again negative-going) that are timed to correspond with the video signal’s colour subcarrier bursts – ie, “burst gating” pulses. IC5d and IC5e invert the latter two pulse trains, to convert them into positive-going form. They are then passed through separate differentiator circuits, to obtain narrow negativegoing pulses from their trailing edges – ie, the vertical sync pulses are differentiated using a 390pF capacitor, 10kΩ resistor and diode D2, while the colour gating pulses are differentiated by a 270pF capacitor, 2.2kΩ resistor and diode D3. These narrow pulses are then used to trigger simple non-retriggerable monostable or “one-shot” circuits, to produce longer pulses of fixed length. These each consist of a flipflop formed by two cross-coupled NAND gate elements, plus an RC timing circuit and a Schmitt inverter. The monostable formed by IC6b, IC6c and IC5b is used to produce a pulse about 1.1ms long, starting at the end of the vertical sync pulse from IC4. The end of the output pulse corresponds closely with the end of the VBI, so it therefore “covers” all of siliconchip.com.au Fig.1(a) Fig.1(b) Fig.1(c) Fig.1(d) Fig.1: these four scope shots show the action of Dr Video Mk2 on Macrovision anti-copying signals from a typical DVD. In each case, the Macrovision signal is the top trace (blue) while the lower trace (yellow) is the cleaned-up (doctored) signal. Also in each case, the top trace is taken from the input at pin 5 of IC1b while the lower trace is the output at CON3, with a 75Ω terminating plug connected. Fig.1(a) shows the Macrovision signal “dancing” pulses that are added following the vertical sync block. These the VBI lines which should ideally be black but can have added Macrovision nasties. Second monostable The second monostable is formed by IC6a, IC6d & IC5a. It is used to produce a much shorter pulse, about 50µs long, starting at the end of each colour burst gating pulse from IC4. This monostable’s output pulse therefore lasts for most of the “active” part of each horizontal line and certainly siliconchip.com.au pulses are constantly changing in amplitude. Fig.1(b) shows the dancing pulses following the colour burst signal. Note that the lower trace shows these pulses completely deleted. Fig.1(c) shows the end-of-file (EOF) positive pulses added to the video line signal at the bottom of the picture. Our circuit drastically differentiates these pulses so they are much shorter. Finally, Fig.1(d) shows the expanded EOF positive pulse on the top trace and the much abbreviated pulse (<200ns) on the lower trace. covers that part of the VBI lines where the “dancing” pulses and fake sync pulses occur. The output of the upper monostable (pin 6 of IC6b) is then fed to IC3a and gated with an inverted version of the vertical sync pulse from pin 3 of IC4. IC3a in turn drives inverter IC5c – ie, IC3a and IC5c together form a positivelogic AND gate. This gating is necessary because the LM1881 can itself be disturbed by the Macrovision pulses, which oc- casionally cause its vertical sync pulse output from pin 3 to begin early. This, in turn, can cause the monostable to trigger early but the gating ensures that if this occurs, the monostable’s output pulse is “blocked” until the end of the vertical sync block. The output from IC5c is a pulse which is high for all of the lines between the end of the vertical sync pulse and the end of the VBI. This is then gated with the 50µs pulses from the lower monostable using IC3b. As June 2004  27 28  Silicon Chip siliconchip.com.au Fig.2: this is the circuit diagram for the Dr Video Mk.2, minus the power supply. Sync separator IC4 and its associated circuits based on IC5-IC9 generate gating signals which operate CMOS switches IC2a & IC2c/d. These switches then strip off any extra sync and dancing pulses on the vertical blanking interval lines, along with the end of field (EOF) pulses, to give a cleaned-up video signal. a result, IC3b’s output goes low for the active part of each line between the end of the vertical sync pulse and the end of the VBI but only for those lines. This signal is called “VBI GATINGbar” on the circuit and is fed to the pin 4 input of gate IC9b. We’ll get back to these pulses shortly. For the moment, let’s turn our attention to gate IC3d. As shown, one input of this gate (pin 13) receives positive-going burst gating pulses from IC5e, while the other input (pin 12) receives negative-going 50µs pulses from the output of IC6d, in the lower monostable. What’s the idea of this gating? Again, it’s needed because of the way the operation of the LM1881 can itself be upset by the Macrovision pulses. In this case, extra burst gating output pulses can be produced during the active part of the VBI lines, at some points in the “dancing pulses” cycle. By using IC3d to gate the burst pulses with the complementary output of the 50µs monostable, we make sure that these unwanted extra pulses are gated out. As a result, the output of IC3d goes low only for the 2.4µs duration of the real colour bursts. These pulses are labelled “CLEANED BG-bar PULSES” on the circuit and drive inverter IC5f. This then turns on CMOS analog switch IC2b during the colour burst period of every video line. And when IC2b turns on, it allows the following 220nF capacitor to charge via a 2.2kΩ series resistor, to the current average value of the composite or Y video signal from IC1a. Black level What’s the idea of this? Well, by convention, the average value of a video signal during the colour bursts is used to establish the signal’s black/blanking level. So, by turning IC2b on only during the burst periods, we ensure that the 220nF capacitor charges to a siliconchip.com.au June 2004  29 first 2.5µs just after the horizontal sync pulses. That’s why this signal line is labelled “EOF GATING-bar” on the circuit. This signal is fed to the pin 5 input of IC9b, which is used here as a low-input OR gate. We’ve seen earlier that the pin 4 input of this gate is fed with the VBI GATING-bar signals. This means that the output (pin 6) of IC9b will go high only at the exact times needed to remove the Macrovision pulses from the video signal – either the dancing pulses and fake sync pulses during the VBI period, or the narrow pulses at the start of the EOF lines in each field. The last step Fig.3: the power supply circuit uses half-wave rectifiers D6 & D7 to drive 3-terminal regulators REG1 & REG2. These in turn produce +5V and -5V supply rails to power the Dr Video Mk2 circuit. voltage which corresponds closely to the video signal’s black level. Removing EOF pulses All of the circuitry we have been discussing so far is almost identical to that used in the first Dr Video project. Let’s look now at the circuitry around IC7, IC8 and IC9, because this is the section that has been added to the new design – to remove those pesky EOF pulses. Because these pulses only occur on the last few lines of each TV field, removing them involves the use of a line counting system. The actual counting is done by IC7, a 4040B 12-stage CMOS binary counter. This is driven by the negative-going “cleaned” BG-bar pulses from IC3d at its CLK-bar input (pin 10), so that its count increments once for each TV line. IC7 is reset by the positive-going vertical sync pulses from IC5d. These pulses are applied to its MR (master reset) input at pin 11, so the counter restarts from zero at the beginning of each new TV field. IC8 is a 74HC138 3-to-8 line CMOS decoder and is used to detect when IC7 has counted 304 lines in each field (ie, about eight lines from the bottom). As well as using the A0-A3 inputs on IC8, this circuit also uses its three additional “enable” inputs to provide what is essentially 6-bit decoding. As a result, the Y7-bar output (pin 7) of IC8 goes low only after IC7 has counted 304 lines. 30  Silicon Chip This pulse is then used to set a simple RS flipflop made up of crosscoupled NAND gates IC9a & IC9d. This means that the pin 11 output of IC9d only goes high on line 305 of each field, where the “active” part of the field has finished and where the EOF pulses are just about to begin. The other input of the RS flipflop is pin 1 of IC9a, which is fed with negative-going vertical sync pulses from pin 3 of IC4. This resets the flipflop at the start of each TV field, taking IC9d’s pin 11 output low again at the same time. The result of all this activity is that pin 11 of IC9d goes high at the beginning of line 305 in each TV field, and then low again at the very end of that field and the beginning of the next. It therefore provides our primary gating signal for removing the Macrovision EOF pulses. IC9c is used to generate the final EOF gating pulses. It does this by gating the signal from pin 11 of IC9d with a differentiated CS-bar output signal from pin 1 of IC4. In this case, the differentiator circuit uses a 680pF capacitor, a 10kΩ resistor and diode D1. The differentiated CS-bar signal consists of narrow (about 2.5µs wide) pulses which begin immediately after the trailing edge of each horizontal sync pulse, so they “cover” the Macrovision EOF pulses. As a result, the output of IC9c pulses low only during the EOF lines and then only for the OK, at this point, we have the 220nF capacitor below IC2b providing a black level voltage, plus some positive-going pulses from IC9b which correspond to the very times when we want to remove VBI and EOF nasties. The final step in cleaning up the video signal is to put these pulses to work. As shown, the pulses from IC9b are fed directly to the gate of analog switch IC2a. This switch in turn connects the 220nF blanking capacitor and pins 8 & 11 of switches IC2c & IC2d. In operation, IC2a is turned on during the critical times for the VBI and EOF lines but left off at all other times. At the same time, IC3c is used to invert the gating pulses from IC9b. It’s output in turn is applied to the gates (pins 6 & 12) of IC2c & IC2d, which are connected in series with the composite/Y video output from IC1a. The end result is that during any of the VBI or EOF gating pulses, IC2c & IC2d are turned off to block the video, while IC2a is turned on instead to clamp the video output to black level. Still with us? Essentially, all of the circuitry around IC3, IC4, IC5, IC6, IC7, IC8 & IC9 is used to produce some fast gating signals which operate switches IC2a, IC2c & IC2d. These then “strip off” any extra sync and dancing video pulses present on the VBI lines, along with any spurious spikes on the EOF lines, and turn these line sections back into innocuous black. So at the junction of pins 1, 8 & 11 of IC2 we get a “cleaned up” video signal. Output amplifiers The “cleaned” video signal is fed to buffer amplifier stage IC10a via a 100Ω resistor. This stage operates with a gain of two and, like the input amplisiliconchip.com.au fiers, is part of an MAX4451ESA dual wideband video amplifier IC. The output from IC10a appears at pin 1 and in the case of a composite video signal, is fed to output socket CON3 via a 75Ω back-terminating resistor. Alternatively, for an S-video signal, the luminance (Y) signal is fed to pin 3 of CON4 (the S-video output socket), again via the back-terminating resistor. Similarly, for S-video signals, the chrominance component is buffered and amplified by IC10b, before being fed to pin 4 of CON4. The 100Ω resistor and shunt 47pF capacitor at the input of IC10a are there to filter out any transients caused by the switching of IC2a and IC2c/d. An identical RC network at the input of IC10b is included simply to provide a matching time delay, so the colour information remains in sync with the luminance. Each output buffer amplifier operates with a gain of 2, to compensate for the 6dB loss caused by the 75Ω back-terminating resistor in series with each output (for cable matching). This gain is set by two 510Ω negative feedback resistors in each of the output amplifier stages. Power supply Fig.4: install the parts on the top of the PC board as shown here. The red dots indicate where component leads and “pin-throughs” have to be soldered on both sides, if you don’t have a board with plated-through holes (top copper shown above; bottom copper shown below). Fig.3 shows the power supply circuit. It’s run from a 9V AC plugpack and uses two half-wave rectifiers (D6 & D7) to produce unregulated ±12V rails. These rails are filtered using 2200µF electrolytic capacitors and fed to regulators REG1 and REG 2 which provide +5V and -5V rails, respectively. The output from each regulator is further filtered using a 100µF capacitor, while the +5V rail also drives LED1 via a 470Ω resistor for power indication. The sync separator (IC4) and all the logic ICs are powered from the +5V rail, while the input and output video amplifiers run from ±5V. Construction Building the Dr Video Mk2 project is very easy, because all the parts (including the sockets) are mounted on a single PC board coded 02106041 (117 x 102mm). Once completed, this board fits snugly inside a standard lowprofile instrument case measuring just 141 x 111 x 35mm. The front panel is even less intimidating than before, since there are no controls at all – just the Power LED to siliconchip.com.au June 2004  31 Fig.5: the two MAX4451 dual op amps (IC1 & IC10) are soldered to the underside of the PC board as shown here. Make sure you install them the correct way around. indicate when the stabiliser is operating. The rear panel provides access to the composite video and S-video input and output sockets, plus the 9V AC input connector. There’s no offboard wiring at all – it’s just a matter of soldering the parts to the PC board. Note that the PC board is doublesided, as the circuit requires a groundplane. However, unless the board is supplied with plated-through holes, you will need to fit short wire “feedthroughs” at various locations on the board, to connect the copper pads on each side. You’ll also have to solder some of the leads of quite a few ICs and other components to both sides of the PC board or, in some cases, to the top copper only. To make this easy, all the wire feedthroughs and “top solder” points are marked with a red dot on the parts layout diagram – see Fig.3. Note: if you buy a complete kit of parts from Jaycar, the PC board supplied will have plated-through holes. This means that you don’t have to fit the wire feed-throughs and that you only have to solder the component leads to the bottom copper pattern. If your board doesn’t have platedthrough holes, begin the assembly by fitting all the wire feed-throughs so you don’t forget them. You can use tinned copper wire or resistor lead offcuts for these. Just make sure that they’re soldered to the copper on each side of the board. That done, install the resistors and the small capacitors, followed by the diodes and electrolytic capacitors. Take care to ensure that the diodes and electrolytics go in with the correct polarity. Table 1 shows the resistor colour codes but it’s also a good idea to check each value using a digital multimeter, before installing it on the PC board. Don’t forget to solder component leads to both side of the PC board (or to the top only if there’s no pad underneath), as indicated by the red dots. pins of each IC to the board pads before the rest of the pins. Again, don’t forget to solder the IC pins on both sides of the board, if this is indicated by a red dot on the parts layout diagram. Next, install the two 3-terminal regulators (REG1 & REG2). This involves bending their leads at right angles so that they lie flat against the Table 2: Capacitor Codes Value 220nF 100nF 12nF 8.2nF 680pF 470pF 390pF 270pF 220pF 47pF Fitting the ICs The next step involves fitting the ICs, again taking care with their polarity. As usual, be careful to minimise the risk of ESD (electrostatic discharge) damage when handling and fitting the CMOS devices – ie, use an earthed iron and solder the supply and ground μF Code EIA Code IEC Code 0.22µF 224 220n 0.1µF 104 100n .012µF 123   12n .0082µF 822   8n2   – 681 680p   – 471 470p   – 391 390p   – 271 270p   – 221 220p   –   47 47p Table 1: Resistor Colour Codes o o o o o o o o o o o No.   1   1   1   2   2   4   1   3   4   2 32  Silicon Chip Value 680kΩ 100kΩ 82kΩ 10kΩ 2.2kΩ 510Ω 470Ω 100Ω 75Ω 24Ω 4-Band Code (1%) blue grey yellow brown brown black yellow brown grey red orange brown brown black orange brown red red red brown green brown brown brown yellow violet brown brown brown black brown brown violet green black brown red yellow black brown 5-Band Code (1%) blue grey black orange brown brown black black orange brown grey red black red brown brown black black red brown red red black brown brown green brown black black brown yellow violet black black brown brown black black black brown violet green black gold brown red yellow black gold brown siliconchip.com.au Silicon Chip Binders REAL VALUE AT $12.95 PLUS P & P These binders will protect your copies of S ILICON CHIP. They feature heavy-board covers & are made from a dis­ tinctive 2-tone green vinyl. They hold up to 14 issues & will look great on your bookshelf. H 80mm internal width H SILICON CHIP logo printed in gold-coloured lettering on spine & cover All the parts mount directly on the PC board, so there’s no external wiring. (Note: the final version differs slightly from the prototype board shown here. H Buy five and get them postage free! Price: $A12.95 plus $A5.50 p&p. Available only in Australia. PC board, as shown. Secure their metal tabs to the PC board using 10mm-long M3 machine screws and nuts before soldering their leads. This mounting method provides a small amount of heatsinking for the two regulators but this is mainly necessary for REG1 (7805), as this device does get warm in operation. By contrast, the 7905 (REG2) runs virtually cold but securing it in this manner is still a good idea. The power LED (LED1) can be soldered in position with its leads straight initially, leaving about 15mm between the LED body and the board. Its leads are then bent forward by 90° about 7.5mm up from the board, so that the LED’s body will later line up with its hole in the front panel. Next, install the 9V AC input connector (CON5) and the two RCA sockets (CON1 and CON3). If necessary, their holes can be enlarged slightly using a jeweller’s needle file, so that the connector lugs all fit correctly. Make sure the connectors are bedded siliconchip.com.au down squarely against the top of the PC board before soldering their lugs to the board pads underneath. Follow these with the two mini-DIN sockets for the S-video connections (CON2 and CON4). Again, make sure that they are seated correctly against the board before soldering their pins. Surface-mount ICs The final step in the board assembly involves fitting the two MAX4451ESA surface-mount ICs (IC1 and IC10). These are in an 8-pin “small-outline” or SOIC-8 package, which is capable of being soldered in place manually – provided you’re careful and use a soldering iron with a fine-pointed tip. Both these ICs mount on the underside of the PC board, as shown in Fig.4. In each case, the IC is installed with its chamfered side towards the front of the board (ie, towards the bottom of Fig.4). Because their leads are only 1.25mm apart, you have to be careful not to create accidental solder bridges between Silicon Chip Publications PO Box 139 Collaroy Beach 2097 Or fax (02) 9979 6503; or ring (02) 9979 5644 & quote your credit card number. Use this handy form Enclosed is my cheque/money order for $________ or please debit my  Bankcard  Visa    Mastercard Card No: _________________________________ Card Expiry Date ____/____ Signature ________________________ Name ____________________________ Address__________________________ __________________ P/code_______ June 2004  33 The rear panel provides access to the S-video and RCA sockets for the video input and output signals. In addition, there’s a power socket to accept the plug from a 9V AC plugpack supply. them during soldering. It’s also necessary to solder each lead quickly, so you don’t damage the IC by overheating! The best way to approach the job is to first lightly tin the IC pads, then tack solder one of the leads to hold the device in position. The remaining leads can then all be carefully soldered and the first lead re-soldered to make the connection permanent. Final assembly The front and rear panels for this project will probably be supplied pre-punched, with screened lettering. These panels can now be fitted to the finished PC board and the entire assembly lowered into the bottom half of the case. The panels slide into the moulded case slots, while the board is secured using four 6mm-long self-tapping screws which mate with matching plastic spigots in the base (one at each corner). Your Dr Video Mk2 is now ready for its final check out. Check-out time There’s no actual setting-up required for this design. However, it’s a good idea to check that the power supply is working correctly before fitting the top cover and putting the 34  Silicon Chip unit to work in your system. First, apply 9V AC to the power input (CON5) from a suitable plugpack. The power LED should light, indicating that the +5V line is present. If it doesn’t, remove the power immediately and investigate because you have a problem. The most likely cause of a “dead” LED is that you’ve installed LED1 with reversed polarity. Check this and if necessary, remove the LED and refit it the correct way around. If the LED is already the correct way around, then you have a more serious problem. One possibility is that the two regulators have been accidentally swapped over, so make sure that the 7805 is in the REG1 position and that the 7905 is in the REG2 position. Neither will work correctly in the other position and they may even be damaged if they have been swapped. The only other likely cause of power supply problems (and a nonfunctioning unit) is that one or more of the electrolytic capacitors have been fitted with reversed polarity. Check the polarity of the two 2200µF electrolytics, the two smaller 100µF units and the two 2.2µF tantalum capacitors. Assuming that LED1 does light, check the +5V and -5V supply rails using your multimeter. Both rails should be within a few tens of millivolts of their nominal values. If so, your Dr Video Mk2 is probably working correctly and should be ready for business. Problems & cures There are only two possible problems that we can envisage, neither of them very likely. One is that if the timing components on pin 3 of IC5b (in the VBI monostable) are all excessively high in value, you may see a few black lines at the extreme top of the picture – and then only with movies in full screen (4 x 3) format, as opposed to widescreen/letterbox. If this happens, it can easily be fixed by reducing the value of the 8.2nF capacitor – eg, to 6.8nF. The other slight possibility is that the same component tolerance problem might occur in the timing circuit for the burst gate monostable – ie, at the input of IC5a. In this case, the pulses from this monostable might be lengthened just enough for switches IC2a & IC2c/d to damage the horizontal sync pulses – causing horizontal jitter or tearing. This is very unlikely to happen but if it does, the remedy is to replace the 220pF capacitor with a lower value SC (say 180pF). siliconchip.com.au Review: Encarta 2004 Premium Suite Multimedia Encyclopaedia Electronic encyclopaedias have been around for a while now and they just continue to get better. This latest offering from Microsoft packs more than an equivalent 60-volume printed set onto a single DVD. It features fast and efficient content searches, built-in report building and rich multimedia content not available in the bound editions. By PETER SMITH E NCARTA 2004 PREMIUM SUITE integrates an encyclopaedia, World atlas, dictionary and thesaurus into one seamless package. It is available in either CD or DVD format and runs on all recent versions of Windows. Multimedia presentation means that along with the facts and figures, you also get sounds, animations and movies. Naturally, this is one of the biggest selling points of what is now the world’s most popular multimedia encyclopaedia. Included in the 2004 edition are 130,000 articles, 25,000+ photos and illustrations, 3000 sound and music clips, 1.8 million atlas locations and over 260 videos and animations. Equally important to content is the ability to be able to pinpoint, extract and organise the material of interest. This is exceptionally easy in Encarta 2004 with the aid of a web-based interface and excellent search facilities. If you’ve used a web browser before, you’ll be able to drive Encarta “out of the box”. Basic features Encarta uses a concept called “centres” to provide casual access to its vast store of information. Each centre is accessible via a drop-down menu on the main toolbar. Available centres include articles, maps, multimedia content, statistics, geographical tours, historical siliconchip.com.au timelines, games and online material. For more than just casual browsing, you can use Encarta’s powerful search facilities to quickly find what you want. A search from the main toolbar draws elements from the encyclopaedia, atlas, dictionary, thesaurus and the Internet and arranges the results in a familiar “web” style page layout. For example, a search for “Albert Einstein” returns a main article on the man, headed with a clickable contents list. A series of related resources appears in the right margin, including links to additional articles, quotations, multimedia content, a sidebar from the Times (in this case, Einstein’s obituary) and links to recommended Internet sites. As you identify content that is pertinent to your work, you can add it to your Favourites list for instant access later. Even better, you can gather text and media “on the fly” using the Researcher tool. This excellent tool also makes it easy to add statistics, charts, tables, notes and more to your reports. Of course, you can also export content to other applications if so desired. Study centre If you’re having trouble getting started on a project, help is available in the Study centre. There you’ll find a Project Starters guide that gives advice on how to write an essay, book report, research paper, lab report and June 2004  35 Fig.1: Encarta opens with the Visual Browser, inviting you to click your way in to its depths. It’s web-based interface means that anyone can use it. Fig.4: Encarta includes a comprehensive World atlas with over 1800 map points. Explore the World using a variety of map styles to learn about populations, climates, politics, economies and much more. You can even place “pins” in the globe, complete with notes for later reference. science project, to name but a few. To help with presentation, you’ll also find a selection of basic templates for use with the Researcher tool. Budding authors will appreciate the Literature Guide, which helps to explain themes, characters and settings from over 120 classics in literature. Also of note is the Curriculum Guide, which is intended as an aid to teachers and parents. Using this guide, you can find information in a range of subjects suitable for secondary and senior secondary levels of study. Internet access Fig.2: a web-based interface and powerful search facilities ensures ease of use. Once you’ve pinpointed what you want, you can add it to your Favourites list for later access or copy desired elements to build your project. The Internet is an important resource for study material, but tracking down relevant information is often a time-consuming task. Encarta’s editors ease the pain somewhat by providing a host of links to recommended material. With its web browser interface, Encarta marries Internet content seamlessly to local CD/DVD content, significantly increasing the amount of information at your disposal. For those concerned about content on the ’net, you can enable the parental controls option to ensure only “family-friendly” hits are returned. Encarta can be updated on-line for one year from date of release at no additional cost. For this edition, the cutoff date is October 2004. Learning can be fun! Fig.3: the Timeline is an intuitive and engaging way of discovering related events in history. Clicking on any hotspot opens a short text description, complete with links to related material. 36  Silicon Chip As well as direct access to information through Encarta’s search facilities, Microsoft has included several other interesting ways of exploring encyclopaedia content. For example, the Interactive Timeline allows you to scroll through time from Earth’s geological beginnings right up to the present. Historical periods and events appear as horizontal strands of time, each clickable to reveal a short text description along with links to related material. Importantly, multiple strands are “overlaid”, allowing you to see how these periods and events interrelate. New to this version of Encarta is the Visual Browser, siliconchip.com.au another way of exploring a particular topic in depth. Essentially, it’s just a series of animated graphical links related to the displayed topic. Nevertheless, it provides a unique way of exploring interrelated information, especially if you’re looking for inspiration or just enjoy browsing. Found in the Tours centre, “Map Treks” are an interesting and informative way of exploring any region on the globe. Based on a variety of map styles from Encarta’s atlas, you can learn all about populations, climates, politics, economies and much more. If all that sounds a little boring, then check out historic cities and places or take a field trip in the 2-D Tours section. Here you’ll find Mount Everest, the Serengeti Plane, Prague, the Kremlin and even the Space Shuttle, to name a few. Each tour incorporates a map of your route, a series of photos and 360° panoramic images that showcase the multimedia content of Encarta. Ancient ruins Fig.5: explore man-made and natural wonders and famous cities in the 2-D Tours centre. 360° panoramic images really bring the experience to life. If that’s not enough, you can visit ancient ruins and landmarks from the past in the 3-D Tours section. With a few mouse clicks, enter tombs in Ramses II’s temple in Abu Simbel, navigate the passages of the Colosseum in Rome or visit Beaumaris Castle in North Wales. Younger students will appreciate the quizzes and interactivities in the Games centre. There you can explore a variety of different topics such as insect structure, world music and natural wonders. As a bonus, the 2004 edition includes 20 high-quality videos from the Discovery Channel. Watch animals in their natural habitat, see where electricity comes from or learn how stars evolve. Note, however, that you’ll need the DVD version of the product to get all 20 videos. Summary This review has focused on the Premium Suite release of Encarta 2004. Cut-down versions with less content are also available but at the recently reduced RRP of $129.95, we think that most will opt for “the works”. At this price, it has to be one of the best educational products on the market. A complete list of system requirements appears below. Note that when installing the product, you have a choice of a minimum or full installation. A full installation copies the entire contents to your hard disk drive, speeding access and eliminating the need to continually switch discs during use. This is by far the preferred method but does require about 2GB of free drive space. Fig.6: interactivities help make the learning experience more memorable. In this anatomy study, any of the 10 body systems can be displayed by clicking on the relevant buttons. The CD version ships on four CDs, whereas the DVD version requires only a single disc. If your PC reads DVDs, get the DVD version. This eliminates potential disk swapping and you get the full complement of SC videos as well. System Requirements • • • • • Windows 98/ME/2000/XP 333MHz or faster processor (500MHz recommended) 64MB of RAM (128MB for Windows 2000 and XP) Super VGA, 16-bit or higher supporting 800 x 600 screen resolution 4MB or more of video memory siliconchip.com.au • • • • • 260MB hard drive space minimum Quad-speed CD-ROM drive (CD version) or DVDROM drive (DVD version) 16-bit sound card with speakers or headphones Internet Explorer 6.0 or later (included on CD, requires 100MB additional hard disk space) Access to the Internet June 2004  37 Open doors & control security systems with this RFID Security Module Tired of fumbling in the dark for your keys? Can’t find the keyhole on a moonless night? Or perhaps you’re just irritated by having to punch in a code each time you want to arm or disarm your security system? End all these little annoyances with a wave of your hand and our state-of-the-art RFID Security Module! By PETER SMITH M ANY HOME SECURITY systems include a keypad situated at the main point of entry or exit. More complex systems may also include a battery-powered remote control device. While these systems have their own merits, they can also be more than a little inconvenient. Having to punch in a code repeatedly can be quite irritating, as can the discovery that the batteries in the remote have finally given up the ghost! This new point-of-entry system solves these problems because it requires no physical contact and no batteries. Essentially, the system consists of a reader module and one or more “tags”. Based on RFID (Radio Frequency Identity) technology, each tag is encoded with a unique identity. 38  Silicon Chip When a tag is brought within range of the reader, it is energised by the reader’s magnetic field. It then transmits its unique code to the reader, which validates the code and arms or disarms the alarm system accordingly. This system also includes the ability to operate an electric door strike. A simple wave of your hand and an “Open Sesame” incantation are all that are required for the door to your castle to spring open! Well – the “Open Sesame” incantation isn’t really necessary. System overview The RFID Security Module is built on a single PC board measuring just 50 x 70mm. In fact, it’s small enough to be concealed behind a standard Clipsal wall plate or similar. It can be operated as a stand-alone keyless entry system or as part of a larger alarm system. Three open-collector outputs and a single digital input are accessible via a 4-way terminal block. One of the outputs is designed to drive a 12V DC solenoid-actuated door strike. These are available from major kit suppliers and most security equipment resellers. The two remaining outputs can be hooked into an existing alarm system to supplement or replace an existing point-of-entry keypad or other remote control device. The digital input can be wired to a tamper switch to detect removal of the cover or the unit from the wall. To cater for varying installations, the module can be programmed to operate in one of four modes, as follows: Mode 1: no alarm features (keyless entry only), door strike energised on tag validation. Mode 2: alarm operation, door strike energised on disarming. Mode 3: alarm operation, door strike energised on arming. Mode 4: alarm operation, door strike energised on arming and disarming. In most cases, the RFID module will be mounted outside the protected perimeter, so you’ll want the strike to be energised on disarming (mode 2). The desired operating mode is selected siliconchip.com.au Fig.1: a hybrid RFID reader module (IC2) from ID Innovations contains all the tag reading electronics. Tag validation and alarm functions are handled by an Atmel AT90S2313 microcontroller (IC1). by performing a simple initialisation procedure, as we’ll see a little further on. Alarm connections Before examining the operation of the module in some detail, let’s take a closer look at the two open-collector outputs and the digital input mentioned above. We’ve labelled the first output “armed”. It is intended for connection to the main control unit to control siliconchip.com.au system arming and disarming. The polarity of this output is jumper selectable to match the control unit’s input requirements (see Table 2). Note: not all commercial alarm systems provide an arm/disarm input, as necessary for use with this system. Consult your alarm system’s manual to determine its suitability. Alternatively, this output can be used to control an engine immobiliser circuit for older vehicles that do not already have such a device. A suitable immobiliser circuit was described in the December 1998 & January 1999 issues of SILICON CHIP. The second output of interest is labelled “alarm”. It can be wired to a normally open input on the main control unit to signal an alarm condition. This output is switched on when the tamper circuit is activated (see below) and also when three consecutive unknown tag IDs are detected. An on-board piezo buzzer beeps and a LED flashes for the duration of an alarm, which is set at five minutes. After the alarm period, the “alarm” output is switched off but the LED continues to flash at a fast rate until June 2004  39 Fig.2: REG1 & diode D2 must be mounted on the copper side of the board, as shown here. Attach REG1 to the board using an M3 screw, nut and washer before soldering its leads. the module is disarmed. For stand-alone use, the “alarm” output can be used to drive a 12V DC siren with a rating of 600mA or less. For larger loads, this output can also be used to drive a 12V relay. Tamper protection If the module is mounted in an accessible location, it’s quite possible that someone may try to detach the assembly or remove a cover in an attempt to bypass security. For this reason, we’ve included a tamper function that can be used to detect such interference. The digital input, which we’ve labelled “tamper switch”, can be wired to one side of a tamper switch, reed Main Features • • • • • • • • • • • • Contactless operation 90-100mm detection range No batteries (in tags) to go flat Stores up to 24 tag ID codes Easy tag addition & removal Works through any nonmetallic material Audio feedback via on-board beeper Tamper detection Arm & alarm outputs Electric door strike output Suitable for home or car use Requires 12V DC <at> 40mA (nominal) 40  Silicon Chip Fig.3: follow this diagram closely when assembling the PC board. The 4-way terminal block (CON2) is made by snapping two 2-way blocks together. Take care with the orientation of all polarised components. switch or mercury switch, depending on the installation. The other side of the switch goes to the ground (negative) input – see Fig.6(d). Either normally open or normally closed switches can be accommodated, as the module automatically configures itself to suit at power up. Obviously, the idea is that if the module is dismounted (or the cover removed), the switch contacts open (or close), changing the state of the switch input. Assuming the module is armed, this generates an instant alarm condition. How it works All of the electronics necessary for tag reading are contained within a single epoxy-encapsulated module from ID Innovations. The ID-12, as it’s named, even includes the field coil, making this an extremely compact and easy-to-assemble project. A continuous 125kHz carrier signal is radiated from the ID-12’s coil while ever power is applied. When a tag is brought within range, its field coil is magnetically coupled to the reader’s coil, inducing an AC voltage across it. Most 125kHz read-only tags contain just a single IC along with the coil itself, which consists of many turns of super-fine copper wire. To reduce overall size, the coils used in miniature glass and epoxy-encapsulated tags are wound on tiny ferrite cores. Included in the IC in the tag are circuits to rectify and filter the voltage from the coil, to provide operating power. Once sufficient power has been stored, the tag transmits its 40-bit ID code by low-frequency modulation of the reader’s carrier signal. For those interested, the data stream is Manchester encoded and transmitted using an ASK (amplitude shift keying) modulation method. To learn more about how this works, refer to the RFID feature in the July 2003 issue of SILICON CHIP. As shown on the circuit diagram (Fig.1), the interface between the ID-12 reader (IC2) and the rest of the circuit is very simple indeed. Whenever the reader receives a tag transmission, it formats the 40-bit code into five 8-bit bytes and adds a few bytes for synchronisation and integrity checking. The entire “frame” is then transmitted in serial format from pin 9. Three different industry-standard transmission formats are supported, selectable by connecting pin 7 to various points. By grounding this pin, our design uses a 9600 bps (bits per second) ASCII format. Atmel microcontroller Serial data from pin 9 of the ID-12 You can easily make 2-way and 4-way pin headers for JP1 and JP2-3 by cutting down a longer strip. siliconchip.com.au is pumped into pin 2 of an Atmel AT90S2313 microcontroller (IC1). Essentially, the program running in this IC is responsible for receiving the data and deciding what action to take. Under program control, the incoming data is reassembled back into byte-sized chunks and a check is made to see if the ID code matches any of the codes stored in the on-board memory (EEPROM). What happens next depends on the selected operating mode. Three output bits (PD4-PD6) drive the base circuits of switching transistors Q1-Q3. If an ID match is found, the microcontroller can switch Q1 on or off to arm or disarm a main alarm system. In addition, it can switch Q3 on for a short period to energise a door strike. Alternatively, if the ID code is not recognised, then an alarm might be triggered by switching Q2 on. The exact sequence depends on the operating mode and the current alarm state, as described previously. Diodes D2 & D3 are included to protect transistors Q2 & Q3 from the back-EMF spike induced by relay and door strike solenoids. The two remaining outputs (PB1 & PB7) used in this design drive LED1 and a piezo buzzer to provide user feedback. On the input side, tamper detection is provided by sensing a level change on the PD3 input bit. During power up, the microcontroller reads this input and stores its state. This method allows either normally open (NO) or normally closed (NC) tamper switches to be used. If the tamper switch changes state while the system is armed, Q2 is switched on to signal an alarm. Three input bits (PD1, PD2 & PB0) allow user selection of various program options (see Table 2). Like the PD3 input, these inputs are pulled high internally. Therefore, installing a jumper shunt changes the respective pin state from a logic high (5V) to a logic low (0V). Parts List Power supply 1 PC board, code 03106041, 51mm x 71mm 3 2-way 5mm/5.08mm terminal blocks (CON1, CON2) 1 6-way 2.54mm DIL header (JP1 - JP3) 3 jumper shunts 1 20-pin IC socket 4 M3 x 10mm tapped nylon spacers 5 M3 x 6mm pan head screws 1 M3 nut & washer EM4001 compatible 125kHz RFID tags to suit (see text) 1 miniature PC mount piezo buzzer (PZ1) (Altronics S 6104 or equivalent) The unit can be powered from any 12V DC power supply (eg, a plugpack) and this is applied to the module via CON1. Series diode D1 prevents damage to all components except Q2, Q3, D2 & D3 in the case of reverseconnected power leads. A 10Ω resistor and 16V zener diode (ZD1) protect the regulator’s input from the high-voltage transients that typically occur in an automotive environment. A 7805 3-terminal regulator (REG1) converts the input to a wellregulated 5V output with the aid of two 100µF filter capacitors. Finally, an under-voltage sensing circuit based on IC3 holds the microcontroller’s reset pin low whenever the supply voltage is below about 4.6V. This prevents inadvertent writes to the on-board EEPROM during power up and power down. Semiconductors 1 AT90S2313-4 (or -10) microcontroller, programmed with RFID.HEX 1 ID Innovations ID-12 RFID module (IC2) (Adilam Electronics) 1 MC34064P-5 under-voltage sensor (IC3) (Altronics Z-7252) 1 4MHz crystal, HC49 package (X1) 2 BC337 NPN transistors (Q1, Q2) 1 BD681 NPN Darlington transistor (Q3) 3 1N4004 diodes (D1-D3) 1 1N4745A 16V 1W zener diode (ZD1) 1 3mm high intensity red LED (LED1) Construction In order to minimise the module’s overall size, two components (REG1 & D2) are mounted on the bottom (copper) side of the PC board. These must be installed first, as shown in Fig.2. Bend the leads of the regulator (REG1) at 90° about 5mm from the body so that, when it is installed, the hole in its mounting tab lines up with the hole in the PC board. Attach the regulator firmly to the board with an M3 x 6mm screw, nut & washer before soldering the leads. Diode D2 must be installed with its banded (cathode) end oriented as shown. With both REG1 & D2 in place, turn the board over and cut off the protruding component leads flush with the PC board surface. Next, on the top side of the board, install all the low-profile components first, starting with the resistors and diodes. Again, the diodes (D1 & D3 and Capacitors 2 100µF 16V PC electrolytic 2 100nF 50V monolithic ceramic 2 22pF 50V ceramic disc Resistors (0.25W 1%) 2 10kΩ 1 150Ω 2 1kΩ 1 10Ω 1W 5% 1 220Ω Table 1: Resistor Colour Codes o o o o o o siliconchip.com.au No.   2   2   1   1   1 Value 10kΩ 1kΩ 220Ω 150Ω 10Ω 4-Band Code (1%) brown black orange brown brown black red brown red red brown brown brown green brown brown brown black black brown 5-Band Code (1%) brown black black red brown brown black black brown brown red red black black brown brown green black black brown brown black black gold brown June 2004  41 This view of the copper side of the PC board shows how REG1 and D3 are installed. zener diode ZD1) must go in with the banded ends around the right way. Install the ID-12 module next. Note that because of the gap between pins 10 & 11, it can only go in one way. On our module, one row of pins were slightly out of line and needed “tweaking” to get an easy fit into the PC board holes. Make sure that it’s sitting square on the PC board before soldering it in place. The ID-12’s pins are spaced on 2mm centres, which means that there’s very little space between the pads. After soldering, use your multimeter to do a continuity test between adjacent pins, to eliminate the possibility of fine solder bridges. The remaining components can now be installed, with attention to the following points: (1) When fitting the IC socket, be sure to align the notched (pin 1) end towards the closest edge of the board. When inserting the microcontroller (IC1) in the socket, note that it also has a notched end that must line up with the notch in the socket. (2) Before installing the crystal (X1), bend its leads at 90° about 2mm from the body. Position it flat on the PC board surface before soldering the Fig.4: check your board against this full-size etching pattern before installing the parts. leads. That done, its metal can should be affixed to the board with a blob of hot melt glue, contact adhesive or similar. (3) Be careful not to confuse the BC337 transistors (Q1 & Q2) with the MC34064-5 under-voltage sensor (IC3), as both devices are supplied in TO-92 packages. The “flat” sides of these devices must go in as shown. For transistor Q3, the metallised (collector) side must face the power-input connector (CON1). (4) The two 100µF capacitors and piezo buzzer (PZ1) are polarised devices and must be inserted with their positive leads aligned as indicated by the “+” markings on the overlay. (5) The mounting arrangements for LED1 will vary, depending on the chosen enclosure. If its lead length is sufficient for it to extend all the way through the front panel, it can be soldered directly in position. Alternatively, it can be attached to the board via short lengths of lightduty hook-up wire and glued into place in the enclosure. Twist the wires tightly together to minimise noise pickup from the ID-12 module. Note the orientation of the flat (cathode) side, which is shown facing JP1 on the overlay diagram. Microcontroller firmware If you’re assembling this project from a kit of parts, then the microcontroller (IC1) will already have been programmed. On the other hand, if you’ve sourced all the parts yourself, then you’ll also need to program this device. The necessary code (RFID. HEX) is available from the download area of the SILICON CHIP web site at www.siliconchip.com.au Initialising the module Before using the module, the desired operating mode must be set and at least one ID programmed. Let’s see how this is achieved. The operating mode is selected by installing a jumper shunt on JP1 and connecting a wire link between two terminals of CON2. Fig.5 shows which terminals to link for each of the four modes. No link should be installed if Mode 1 operation is desired. Once the link (if needed) and jumper are in place, connect 12V DC to the power input terminals (CON1). Be particularly careful that you have the Fig.5: a temporary wire link must be inserted in the 4-way terminal block as part of the initialisation procedure, in order to select Mode 2, 3 or 4. If you don’t need the door strike function, then it’s not important which alarm mode you choose. 42  Silicon Chip siliconchip.com.au Fig.6(a): an electric door strike can be connected for easy access to your home. Fig.6(c): basic alarm functionality can be achieved by connecting a siren directly to the “alarm” output. Alternatively, this output can drive a 12V relay. Fig.6(b): the “arm” and “alarm” outputs can be used to interface the module to an existing alarm system. The “arm” output can also be used with an engine immobiliser circuit in a car. The SILICON CHIP Engine Immobiliser requires a 2.2kΩ pull-up resistor (shown in grey) to +12V, with JP2 removed to select a low output when armed. positive and negative leads around the right way, otherwise transistors Q2 & Q3 (and perhaps diodes D2 & D3) will self-destruct! Assuming all is well, the module will immediately “beep” to indicate the chosen mode. For example, with a link between the “door strike” output and the “tamper switch” input, the module will beep four times to indicate that Mode 4 has been selected. This operation also erases all of the microcontroller’s EEPROM, so if you’ve decided to switch modes after programming some tags, you’ll need to program them again. Now power off and remove the jumper wire, as well as the shunt on JP1. The module is now ready to be programmed for tag recognition. Master tag programming The very first tag that is detected by the module after the initialisation procedure is assigned special status. This “master” tag, as we’ll refer to it, will be needed when ever you want to add or remove other tags. siliconchip.com.au Fig.6(d): a tamper switch in mandatory unless the unit is completely inaccessible. Here’s how to connect one. Fig.6(e): a battery-backed 12V supply is required to power the module. Existing alarm systems will already have such a supply. For standalone use, you’ll need to wire up your own battery and charger as depicted here. A great little SLA float charger was described in the March 2003 issue of SILICON CHIP. Power up again and swipe the tag that you want to be assigned as the master. Once the tag is within about 90-100mm of the top or bottom of the module, it will beep once to indicate that the ID code has been received and stored. Now, when ever you swipe the tag, it’s unique ID code will be immediately recognised. For keyless operation (Mode 1), the module beeps once and energises the door strike each time the tag is swiped. For alarm operation (Modes 2-4), the alarm state is toggled each time the tag is swiped. One beep indicates system arming whereas two beeps indicate disarming. You’ll also note that when Table 2: Jumper Functions Jumper IN OUT JP1 Erase all IDs, set mode Armed output low when disarmed Enable ID add/ remove Normal operation Armed output low when armed Disable ID add/ remove JP2 JP3 armed, the LED flashes at 2-second intervals. The door strike is energised as appropriate for the specific mode. Adding & removing other tags Up to 24 tag ID codes can be stored in the microcontroller’s memory. To enable the addition or removal of tag codes from memory, first install a jumper shunt on JP3. With the jumper in place, swipe the master tag. The module will perform the usual arm or disarm, depending on the operating mode. In addition, detection of the master tag starts an internal 4-second timer. Within that 4-second period, any tag that is swiped will be added to memory if it does not already exist and the module will beep once. Conversely, any tag that already exists in memory will be removed and the module will beep twice. If you try to add more that 24 tags or if the microcontroller fails to successfully add or remove a tag code for any reason, the module will beep four times. Each time a tag is swiped, the June 2004  43 Where To Get The Parts (1). Kits and “key fob” style tags for this design will be available from Altronics and Dick Smith Electronics. (2). The ID-12 RFID module is available from Adilam Electronics, who also stock a range of Sokymat RFID tags. Contact Adilam on (02) 9704 9200 or point your browser to www.adilam.com.au (3). Electric door strikes are available from Altronics, Dick Smith Electronics and Jaycar. The unit pictured at left is typical and came from Altronics. 4-second timer is restarted. If no tag is swiped within the timing period, the timer expires and the module beeps once, returning to normal operation. It’s then necessary to swipe the master tag again before more tags can be added or removed. If you install the module in an inaccessible location (such as inside a wall), you may wish to leave the “add/ remove” jumper (JP3) in place. Note that, in some instances, this could pose a security risk. If the master tag is “borrowed” by a would-be intruder, they may be able to add their own tag to the system and return the master without your knowledge! Installation & wiring The low operating frequency of this system enables operation through non-metallic materials. This means that it can be installed behind walls and inside consoles, for example. The main limitation here is the maximum operating range. Our prototype operates at up to 95mm, although large metal objects nearby tend to reduce this range. When in doubt, test before reaching for your hammer and chisel! As previously mentioned, the module is also small enough to fit behind a standard Clipsal wall plate or similar. For brick walls, a stand-off box will be required as well. Fig.6 shows several basic hook-up schemes, covering both stand-alone operation and use with a more comprehensive alarm system. It’s up to you to choose the scheme that best suits your application. If using the door strike option, the ground return wire (back to battery negative) should be run using heavyduty cable, especially for long runs. If using multi-core alarm cable, combine two cores in parallel to achieve similar results. A separate wire from the battery positive to the door strike solenoid is also advisable. When used with an engine immobiliser in a car, the module can be either powered permanently or only when the ignition is switched on. The latter method eliminates battery drain as well as the need to arm the module each time you exit the vehicle. However, it does mean having to swipe your tag after inserting the keys in the ignition. Which ever method you choose, the positive power lead must be wired via This photo shows a sample collection of tags, including the key fob and “credit card” styles mentioned in the article. 44  Silicon Chip the fuse box. The negative lead simply connects to chassis ground. How secure is it? Each tag is factory-encoded with a unique 40-bit number. This means 240 possible combinations – a very big number indeed. It’s therefore extremely unlikely that someone will have a tag with the same code as yours. It’s also impossible to use a scanning device to “crack” the code because the module generates an alarm as soon as three consecutive unknown IDs are detected. Not only that, but the very low tag to reader transmission speed means that it would probably take years to run through all of the possible combinations. As with lock and key security, it might be possible to “borrow” a tag and copy it. This could be achieved by reading the ID and programming it into a read/write tag, effectively duplicating the original. Note, however, that this requires specialised equipment not typically found in an intruder’s toolkit! It’s the wiring from the module to the main alarm (if used) and to the power supply that’s probably the most vulnerable. It’s therefore important that all wiring is well concealed and completely inaccessible without first triggering an alarm. Note that some alarm systems can be set up to detect cut wires and other forms of tampering. Of course, even simple alarm systems must have a well-maintained battery backup supply to continue operating in a blackout. Tag compatibility The RFID reader module used in this system will work with any “EM4001” compatible read-only tags. A large range of tag styles is available (see www.sokymat.com) but due to minimum order requirements, kit suppliers will probably only carry a couple of different types. The most useful tag for this project is probably the “key fob” style. It isn’t much thicker than your typical automotive fob and it’s virtually indestructible. Best of all, there are no batteries to go flat! The credit-card sized tag might also be popular. There’s no need to open your purse or wallet with one of these – just swipe the whole thing past the SC reader for instant access! siliconchip.com.au S T O C K TA K E SA LE! •New model better than ever! •Clean up video signals for better copies and playback. •Removes piggyback signals causing interference. •Works up to Macrovision 4. •Includes PCB, case, electronic components and mains plugpack •Some SMD soldering required. or +65°C heating. •Powered from 12VDC. •Peltier device for reliable operation. •Holds 6 x 375ml cans. Cat. GH-1376 $ .95 •Large LCD for superior picture clarity. •Optional electronic door strike control. •Quality colour CMOS camera. •Supplied with mounting and wiring Cat. QC-3612 hardware. $ .00 44 499 OUR APOLOGIES 1W Luxeon LED Hand Torch •Superior brightness. •100,000 hour LED life. •210 L) x 18(W) x 25(dia)mm. Cat. ST-3333 $ .95 59 GH-1375 - 4L 12VDC / 240VAC Cooler / Warmer Due to our stringent safety requirements, the previously advertised 12VDC/240VAC version of this unit has been deemed unsuitable for use in Australia, and withdrawn from sale in all Jaycar Electronics stores. Alternatively, the 12VDC powered unit shown above is available (Cat. No. GH-1376) at a competitive price. Jaycar apologises for any inconvenience caused. NEW STORE IN ADELAIDE 1168 South Rd. Clovelly Park. SA. 5042. Ph: (08) 8276 6901 1W Luxeon LED Head Torch •3 level selectable brightness. •Water resistant case. Cat. ST-3321 •Strobe function. $ .95 We’ve Moved 69 You can still call us on (02) 9439 4799 2004 OUR MASSIVE 424 PAGE CATALOGUE IS NOW AVAILABLE! You can find it in store for just $3.95 Tiny FM Radio •Automatically scans for stations. •44(L) x 44(W)mm! Cat. AR-1770 $ .95 9 AA Kingcell 40 Pack Remote Control Clown Fish •High quality alkaline batteries. •Almost half the price of small pack equivalents. •Realistic looking fish with full manoeuvrability. •Chase the fish in your fish tank! Cat. GT-3225 $ .95 29 19 •Supports the most common memory cards including XD •High speed USB 2.0 data transfer. Cat. XC-4853 $ .95 59 18 0 0 0 2 2 8 8 8 Freecall For Orders •1.5-30VDC <at> 1A. •Voltage and current LCD display. •Over voltage/current and short circuit protection. Cat. MP-3095 $ .00 199 Mini Keyring Stud Finder •Locates studs quickly and easily. •LED indication. Cat. QP-2284 $ .95 8 Anti Fog Shaving Mirror with Radio •Water resistant case. •Hangs on the shower head. •Actual model is white Cat. GH-1059 $ .95 Anti-Glare Monitor Filter Surplus •Quality multi-layer glass filters. •Ltd qty availiable. Filter to suit 16”-18" monitors XC-4647 Filter to suit 20”-22" Both Types monitors XC-4648 $ .95ea 39 Digital Map Distance Calculator 12 in 1 USB 2.0 Card Reader 99 29 GRAB YOUR COPY NOW Cat. SB-2332 $ .95 Cat. KC-5390 $ .95 Switchmode Lab Power Supply NOW OPEN Our Gore Hill Store has moved to: 96 Pacific Highway, St. Leonards. NSW. 2065 June 2004 WE ARE EMBARRASINGLY OVERSTOCKED ON MANY ITEMS! WE MUST MOVE THESE TO MAKE ROOM FOR NEW UNITS. WE LOSE - YOU WIN! SPECIALS START NEXT PAGE. Colour Video Doorphone Dr Video Kit MkII 4 Litre Cooler / Warmer with 5.6" LCD Monitor •Ref: Silicon Chip June 2004. •Up to -25°C cooling •Converts map scale to real distance. •Selectable kilometres or miles. •Easy scale calibration. Includes clock, timer, compass, and light. Cat. XC-0375 $ .95 19 No rainchecks on items marked Ltd Qty. BARGAIN USB Radio and Remote Control •FM playback and recording. •Remote control can be used for many PC functions. Cat. XC-4880 $ .95 79 Can even co ntrol MS Powerp oint presentatio ns LED Message Display Board SAVE $15 Rear View Mirror with Hands Free Kit Car Boot Extender •Up to 60 character messages. •Bright LED display. •Ltd Qty. Was $59.95 •Built in 60 second voice recorder. •Loudspeaker or earpiece operation. Was $89.00 Cat. GG-2120 $ .00 SAVE $15 •Great for transporting large objects. •Includes blade and LED warning light. Was $24.95 Cat. GH-1100 $ .95 SAVE $10 Cat. XC-0190 $ .95 44 74 14 Handheld Metal Detector Rear View Mirror with Parking Sensor Illuminated Mini Fogger •Beeps when metal is detected. •400mm long, 140mm diameter sensor area. Was $69.95 Cat. QP-2272 SAVE $ .95 $20 •No more ‘bump parking’. •Voice recording and hands free. Was $189.00 •Great mystical effect. •Built in Halogen light. •Ltd Qty. Was $79.95 49 SAVE $30 Cat. YH-5425 $ .95 SAVE $30 49 Cat. GG-2122 $ .00 159 Swivel Bases for TV’s and Pot Plants Ioniser Pet Brush Aqua Dome •Ensure optimum TV viewing. •Rotate plants into the sunlight. •Ltd Qty. 12” XC-4644 Was $14.95 $ .45 •Repels dirt and odours. •Adds volume and lustre as you brush. Was $19.95 •Realistic swimming fish. •Random movement from rotating magnet. •Ltd Qty. Was $24.95 Cat. GH-1210 $ .95 SAVE $5 16” XC-4646 Was $19.95 7 9.95 $ Glowing Halloween Badges - Buy Now and SAVE! •Electroluminescent (EL) glowing. •Great for Halloween. •Ltd Qty. Scream Badge GG-2110 Fish Badge GG-2112 Cemetery Badge GG-2114 Happy Halloween Badge GG-2116 Was $14.95 7 SAVE $5 Cat. GH-1200 $ .95 19 14 Hand Held Body Fat Analyser Power Jump Rope Phone Style Intercom •Calculates your body fat content. •Keep track of your weight. •Ltd Qty. Was $29.95 Cat. QM-7252 $ .95 •Automatically counts the number of jumps. •Ltd Qty. Was $19.95 •Ergonomic handset. •Mains powered, 30m interconnecting cable. Was $79.95 14 HALF PRICE SAVE $5 Cat. AM-4320 $ .95 Cat. YS-5550 $ .95 59 14 60CD Storage Drawer 32 Disc DVD Wallet CD-R Pen 4 Colour Pack •Holds DVDs and inserts. •Leather look finish. •Ltd Qty. Was $29.95 Cat. AR-1491 SAVE $ .95 $5 •Black, green, blue and red. •Great value! Was $9.95 4 Sound Activated Cot Light Surge Protector Fold Up Solar Charger •Dual mains and telephone protection. •Protects valuable equipment. •Ltd Qty. Was $29.95 •3, 6, 9, and 12V output. •354(W) x 230(H) x 15(D)mm unfolded. •Ltd Qty. 2003 Cat. Price $59.95 SAVE $12 Cat. ST-3029 $ .95 SAVE $10 9 UV Glow Pen •Refills available. •UV LED illuminates the barrel. •Ltd Qty. Was $14.95 SAVE $5 Cat. ST-3063 $ .95 9 HALF PRICE Battery Bank for Digital Cameras Cat. TM-3040 $ .95 24 19 •Illuminates when your baby cries. •Clips to cot or cradle. •Ltd Qty. Was $19.95 SAVE $10 Cat. MS-4028 $ .95 19 •High capacity Ni-MH batteries. •Allows longer run time. •Ltd Qty. Was $79.95 SAVE $20 Cat. MB-3590 $ .95 47 Cat. MP-3070 $ .95 59 Flashing and Dimming Torch Ultimate Utility Tool LED / Halogen Hand Torch •Superbright 10mm LED. •Microprocessor controlled. •Ltd Qty. Was $49.95 •A must for camping and handymen. •Includes pouch. Was $24.95 •Strong aluminium with rubber grip. •Selectable Halogen or LED use. •Ltd Qty. Cat. ST-3328 Was $39.95 $ .95 SAVE $10 Cat. ST-3330 $ .95 34 SAVE $15 SAVE $10 Cat. TH-1907 $ .95 14 29 5 in 1 Pen Multi Colour Flashing Pen 8 in 1 Octopus Screwdriver Electric Corkscrew •Stylus, magnet, screwdrivers, & a pen. •Very versatile. •Ltd Qty. Was $14.95 •Multi coloured LED in the barrel. •Refills available. •Ltd Qty. Was $24.95 •Integrated torch. •All tools neatly fold into the body. SAVE •Ltd Qty. $5 Was $24.95 •Effortless cork removal. •Rechargeable. •Ltd Qty. Was $84.95 SAVE $20 Cat. ST-3097 $ .95 9 SAVE $5 SAVE $20 •Soft inserts for protection. •Easy slide drawer. 2003 Cat. Price $24.95 SAVE Cat. AR-1495 $5 $ .95 HALF PRICE All Types (ea) $ .45 HALF PRICE SAVE $10 Cat. ST-3092 $ .95 14 Cat. TD-2054 $ .95 19 No rainchecks on items marked Ltd Qty. Cat. YS-5525 $ .95 64 www.jaycar.com.au Online Internet Ordering 960Hr Time Lapse VHS Recorder •40 days recording on an E-180 tape. •Four head recording. 2003 Cat. Price $899.00 Cat. QV-3053 $ .00 SAVE 00 $2 699 Glass Breakage Alarm ID Wallets and Lanyards Cat 5 Audio/Video Balun •Sounds loud siren when triggered. •Can also be used as an entry alarm. •Ltd Qty 2003 Cat. Price $15.95 Cat. LA-5008 $ .95 SAVE $6 •Ideal for security and ID tags. •Ltd Qty SAVE Wallet Pk10 Cat. LA-6001 $2 $ .95 Was $8.95 •Transmit A/V signals over very long distances. •One required at each end. Was $95.00 SAVE $35.00 4mm Auto-Iris Lens •Aperture f1.4 to f88. •Camera must have Auto-Iris controlling ability. Was $349.00 •High quality for best realism. •Flashing LED. Was $69.95 Cat. LA-5313 $ .95 49 SAVE $60 Digital Camera Pen •320 x 240 pixel images •2MB memory. •RS-232 download - lead supplied. 2003 Cat. Price $119.95 Cat. QC-3380 $ .95 Cat. LA-5488 $ .00 849 Cat. QC-3320 $ .00 Panning Base and Controller •Suit all of our pro style cameras. •Ltd Qty 4mm QC-3340 6mm QC-3342 8mm QC-3344 Was $14.95 SAVE All Types (ea) $ .95 $5 •Manual and automatic pan control. •IR remote control, 500g maximum load. SAVE •Ltd Qty $60 Cat. QC-3208 2003 Cat. Price $ .00 $179.00 •420 TV Lines. Was $149.00 •420 TV Lines. Was $319.00 129 B&W CCD, Infrared Colour CCD Dome •380 TV Lines. Was $99.95 •480 TV Lines. Was $299.00 SAVE $20 Cat. QC-3468 $ .95 Cat. QC-3498 $ .00 10" B&W 4 Channel Switching Monitor 12" B&W 4 Channel Quad Monitor Was $259.50 SAVE $40 Cat. QM-3403 $ .50 279 Was $599.50 SAVE $100 Cat. QM-3407 $ .50 499 219 18 0 0 0 2 2 8 8 8 Freecall For Orders 2.4GHz Wireless Modules 34 Economy C Mount Lenses SENSOR INSIDE Cat. QC-3473 SAVE $ .00 $20 SAVE $50 119 •Utilise wireless communication between your AV appliances. •Small power supply circuit and hardware required. Transmitter Was $34.95 Receiver Was $49.95 PIR Night Light •6 LEDs, PIR activated. •1 minute switch off delay. Was $24.95 SAVE $5 Cat. QC-3309 $ .00 Cat. LA-5160 $ .95 19 Security Keypad 269 B&W CCD Dome, Infrared •380 TV Lines. •Ltd Qty 2003 Cat. Price $209.00 SENSOR INSIDE SAVE $70 219 Cat. QC-3338 $ .95 289 Standard Lens model shown. 159 •B&W CMOS camera, 4.5" monitor. •Up to 100m SAVE transmission $60 Cat. QC-3254 distance. .00 Was $279.00 $ •240 TV Lines. Was $59.95 84 Colour CCD Cat. QC-3260 $ .00 2.4GHz Wireless Camera /Monitor Pro Colour CCD, Auto Iris, Audio SAVE $15 Was $199.00 Roof Mount Camera Bracket B&W CCD Pinhole, Audio 49 60 •Designed to mount large housings up to 30kg. •Total length 700mm. SAVE •Ltd Qty $15 Was $49.95 B&W CMOS Pinhole, Audio SAVE $10 Cat. QC-3424 $ .00 129 B&W CMOS Was $229.00 9 99 GREAT PRICES ON CCTV EQUIPMENT! Cat. QC-3442 $ .95 SAVE $5 9 •The simplest way to set up video surveillance. •Transmitting camera, receiver, and power supplies all included. SAVE Cat. QC-3255 $70 •Ltd Qty $ .00 •Protect your home from intruders. •Contains all hardware to get operational. •See website for contents. •Ltd Qty. SAVE $150 Was $999.00 269 Dummy Surveillance Camera 6 Cat. LA-6002 $ .95 AV-GAD 8 Zone Home Alarm Deal 2.4GHz Wireless Cameras / Receivers AEI 6 Zone Home Alarm Deal SAVE $20 Was $14.95 9 •Protect your home from intruders. •Contains all hardware to get operational. •See website for contents. •Ltd Qty Was $319.00 Cat. LA-5364 SAVE $ .00 $50 SAVE $20 Lanyard Pk10 SAVE $90 Cat. QC-3443 $ .00 119 14" Colour 4 Channel Monitor with Audio Was $699.00 SAVE $150 Cat. QM-3414 $ .00 549 No rainchecks on items marked Ltd Qty. •Fully programmable 1-8 digit code. •Single relay output. Was $66.95 SAVE $15 Cat. LA-5355 $ .95 51 Electric Door Strike •Electronic access. SAVE •Requires $10 12VAC/DC <at> 800mA pulse. Was $49.95 Cat. LA-5078 $ .95 39 SAVE $5 SAVE $10 Cat. QC-3590 $ .95 29 Cat. QC-3592 $ .95 39 Two Zone Alarm Controller •Ideal for boats, caravans etc. •Entry and exit delay. •Ltd Qty Was $39.95 Cat. LA-5590 $ .95 SAVE $10 29 6 Core Alarm Cable - 30m Roll •ACA approved. •5mm OD, white insulation. Was $34.95 SAVE $10 Cat. WB-1596 $ .95 24 Combined Siren/Strobe •120dB dual piezo sirens. •Rainproof ABS enclosure. Was $32.50 Cat. LA-5308 $ .50 SAVE $7 25 Notebook HDD Adaptor USB 2.0 to Ethernet Converter USB PC Security Key Multi Transfer Panel •Full speed Ethernet connection. •Ideal for notebooks without network card. •Ltd Qty Was $64.95 •Secure PC authentication. •Protects files, email and more. •Ltd Qty Was $199.00 •Peripheral connection from the front of PC. •Infrared support and thermocouple. •Ltd Qty SAVE 2003 Cat. XC-5171 0.95 Cat. $ .00 Price $99.95 $3 Cat. YN-8065 $ .95 SAVE $15 49 ATA-100 IDE Cables •Round 600mm, 3 socket. •Ltd Qty Cat. PL-0962 - Blue Cat. PL-0964 - Black Was $19.95 Both Types (ea) $ .95 SAVE $12 7 GSM Data Bank 149 Cat. XC-5103 $ .95 29 69 CPU Fan Alarm PC Ventilator •Protection against overheating. •Sounds buzzer if fan stops. •Ltd Qty Was $13.95 •Better cooling to avoid overheating. •Adjustable fan direction. •Ltd Qty Was $43.95 Cat. XC-5034 $ .95 7 SAVE $6 Cat. XC-5045 $ .95 29 •Ensure cooling after shutdown. •Selectable run time. •Ltd Qty Was $39.95 49 19 •Dual scroll wheel. •PS/2 connection. 2003 Cat. Price $49.95 Cat. XC-5058 $ .95 HALF PRICE •Transform your PC. •Great used with lighting effects. Was $24.95 Cat. XC-4638 SAVE $ .95 *case not $5 included Optical Scroll Mouse Fan Cool-down Timer •Multi format media card support. •Dual USB port. •Ltd Qty •May be display model. Was $99.95 Cat. XC-4769 SAVE $ .95 $50 7 Perspex Window Kit SAVE $14 Card Reader / USB Hub •Complete SIM card data management. •Portable and reliable .•Ltd Qty 2003 Cat. Price $49.95 SAVE $20 Cat. XC-4838 $ .00 SAVE $50 •2.5" to 3.5" kit with mounting bracket and screws. •Same as our regular model, but you can only get two fasteners into thebracket. Cat. PL-0755 $ .50 •Ltd Qty 19 Cat. XM-5125 $ .95 39 SAVE $10 USB Media Card Readers Internal Card Reader USB Repeater Cable 5 Port USB Hub •Compact flash, smart media, IBM micro drive. •Two models, •Ltd Qty Cat. XC-4812 Was VE $ .00 $69.00 SA $30 •Supports CF, SM, MEM stick, SD, MMC cards. •Suits 3.5" bay. •Ltd Qty Was $54.95 SAVE $15 •Full speed USB up to 20m (using multiple cables). •5m long. Was $34.95 •Internal suits 3.5" bay. •LED port status. 2003 Cat. Price $59.95 39 Was $79.95 SAVE Cat. XC-4770 .00 $40.95 $ 39 Cat 5 Punch Down Tool •Internal impact mechanism. •Blades not supplied (see 2004 cat pg 187). Was $29.95 Cat. TH-1741 $ .95 24 SAVE $5 Cat. XC-4855 $ .95 39 Adjustable Punch Down Tool USB Notebook Camera •100k (352 x 288) pixels. •45(L) x 29(W) x 16(H)mm. Was $59.95 44 •RJ-12/RJ45/USB testing. •13 status LEDs. Was $119.00 SAVE $20 Cat. XC-5075 $ .95 49 Network Cable Tracer •Multi tone test signal. •Inductive pickup. Was $199.00 SAVE $80 Cat. XC-5083 $ .00 119 Cat. XC-5077 $ .00 79 Cat. QC-3225 $ .95 49 SAVE $40 SAVE $80 Cat. XC-4825 $ .95 39 4 Port USB Hub •Will store in a dual PCMCIA slot when not in use. •Ltd Qty 2003 Cat. Price $59.95 SAVE $20 Cat. XC-4816 $ .95 39 Remote Control Alarm Clock Dynamo IR Remote Control •Performs an IR function at preset time. •Blue EL backlight. Was $29.95 SAVE $10 Cat. AR-1732 $ .95 •No batteries required. •Pre-programmed. •Ltd Qty Was $59.95 SAVE $15 19 Cat. AR-1718 $ .95 44 Changeable Face Plates Remote Coffee Table Remote Smart Network Cable Tester •4 identifiable terminators. •2 line LCD, soft carry case. Was $239.95 SAVE $10 SAVE $20 24 •Adjustable impact SAVE $11 mechanism. •Blades not supplied (see 2004 cat pg 187). Cat. TH-1740 Was $55.00 $ .00 NETWORK CABLE TESTERS SLASHED! Budget Cable Tester Multi Cable Tester •UTP/STP/coaxial testing. •Twisted pair status LEDs. Was $69.95 Cat. XC-4839 $ .95 SAVE $10 Cat. XC-5086 $ .95 159 •Preprogrammed, Teletext feature. •2 face plates supplied. •Ltd Qty 2003 Cat. Price $49.95 No rainchecks on items marked Ltd Qty. SAVE $20 •Huge range of functions. •320(W) x 185(D) x 48(H)mm. •Ltd Qty Was $129.00 Cat. AR-1705 $ .95 29 SAVE $30 Cat. AR-1716 $ .00 www.jaycar.com.au 99 Online Internet Ordering 50W Adjustable Strobe 4 Way Light Chaser Koss / Ford Headphones •Variable flash rate. •240(W) x 220(H) x 170(D)mm. •Ltd Qty Was $129.00 Cat. SL-2991 $ .00 SAVE $40 •240VAC up to 300W per channel. •Control module only. Was $56.95 •Branded by Ford, made by Koss. •2 pairs included. •Ltd Qty Was $39.95 Cat. AA-2046 $ .95 SAVE $10 SAVE $12 89 Cat. AA-0312 $ .95 29 44 Mirror Mat Colour Wheel •Ideal for home, car, and nightclubs. •400 x 400mm, adhesive backing. •Ltd Qty HALF Was $14.95 PRICE •Suits PAR 36 can lights. •230mm dia, mains powered motor. Was $31.50 Cat. SL-2961 $ .50 SAVE $5 Cat. AX-3670 $ .45 7 •Perfectly matched electret elements. •Excellent stereo separation. SAVE $10 Was $39.95 Cat. AM-4070 $ .95 29 Earphones / Inline Microphone •1.8m lead to 2 x 3.5mm plugs. •Black pouch included. •Ltd Qty Was $19.95 •Extends to almost 2m. •45kg capacity, ideal for PA. Was $109.00 Cat. CW-2860 $ .00 SAVE $20 89 Pro Dynamic Microphone Stereo Microphone 17 Heavy Duty Speaker Tripod 26 •Ergonomic Zinc-diecast case. •Unidirectional dynamic type. Cat. AM-4094 •Ltd Qty $ .95 Was $59.95 SAVE $20 39 10" 120W Powered Subwoofer •High and low level inputs. •Auto on, phase reversal, level adjustment. •Ltd Qty Cat. CS-2454 2002 Cat. .00 SAVE $ Price $499.00 $150 349 Phono / Mic Preamp HiFi Preamp 150WRMS Sub Amp Module •5% RIAA EQ capacitors. •70 x 60mm board. •Ltd Qty 2003 Cat. Price $26.95 Cat. AA-0234 $ .95 •Flat frequency response. •Vol, bass, mid, treble, and more. •Ltd Qty 2003 Cat. Cat. AA-0315 Price $89.95 $ .95 SAVE $25 •Adjustable crossover frequency. •150WRMS <at> 4 ohms, •100WRMS <at> 8 ohms. •Ltd Qty Was $319.00 SAVE $80 19 SAVE $7 64 6W Amp Module Front / Rear Fader 5 Input DJ Mixer •Great for discman, MP3 player etc. •High and low level inputs. SAVE •Ltd Qty $6 Was $23.95 Cat. AA-0340 $ .95 •RCA input / output. •No power required. Was $19.95 •Cross fade, LED VU meters. •Talk over function, mains powered. Was $169.00 Cat. AM-4210 $ .00 SAVE $20 Cat. AA-0485 $ .95 SAVE $5 14 17 High to Low Level Converter Car Super Tweeters •Wire speaker outputs to RCA inputs. •Adjustable levels. Was $23.95 •Built in crossover capacitor. •40WRMS power handling. Was $7.95 22 3" Magnetically Screened Woofer •15WRMS, 8 ohm impedance. •Ltd Qty 2003 Cat. Price $27.95 Cat. CW-2103 $ .95 22 SAVE $5 12" Titanium Coated Subwoofer •150WRMS, 4 ohm impedance. •Ltd Qty Was $129.00 SAVE $55 Cat. CS-2276 $ .00 74 18 0 0 0 2 2 8 8 8 Freecall For Orders 17 Cat. CS-2218 $ .00ea 5 4.5" VIFA P11 Mid/Woofer 6" All Purpose Speaker •60WRMS, 8 ohm impedance. •Ltd Qty Was $39.95 •4 WRMS, 4 ohm impedance. •Ltd Qty Was $7.50 SAVE $10 Cat. CW-2150 $ .95 SAVE $2 29 5 •300WRMS, 4 ohm impedance. •Ltd Qty Was $309.00 •200WRMS, 4 ohm impedance. Was $159.00 SAVE $50 Cat. AS-3012 $ .50 15" Double Magnet Subwoofer 12" Carbon Fibre Subwoofer SAVE $40 Cat. CS-2350 $ .00 Cat. CS-2246 $ .00 109 No rainchecks on items marked Ltd Qty. 269 9 •Suits 5AG fuses. •4G in, 2 x 8G out. •Ltd Qty Was $34.95 SAVE $15 Cat. SZ-2072 $ .95 19 239 Electronic Sub Crossover SAVE $2.95 Cat. AA-2029 $ .95 Cat. AA-0500 •3 digit LED display. $ .00 •4 individually fused outputs. 149 Cat. AA-0480 $ .95 HALF PRICE 4 Way Gold Power Distribution Block Gold Distribution Blocks with Voltage Display •Adjustable crossover freq. •RCA connection, 9-16V supply. Was $32.95 Cat. AA-0475 SAVE $ .95 $10 SAVE $6 Hands Free Headset •Adjustable boom. •Ideal for hands free two way communication. •Ltd Qty Was $22.95 Cat. AA-2019 SAVE $ .95 $5 Wafer Fuse Style SZ-2076 5AG Fuse Style SZ-2077 Was $49.95 Both Types (ea) $ .95 34 SAVE $15 Speaker Cabinet Corners Pk 8 •Great for PA cabinets. Was $11.75 Cat. HM-3830 $ .75 6 SAVE $5 10" Profile Polycone Subwoofer •200WRMS, 4 ohm impedance. •Ltd Qty Was $99 Cat. CS-2360 $ .00 SAVE $15 84 6.5" Coax / Split Speaker Combo •40WRMS, 4 ohm impedance. •Ltd Qty 2002 Cat. Price $119 SAVE $50 Cat. CS-2296 $ .00 69 40MHz Dual Trace Oscilloscope •Alternating triggering. •Practical panel layout. •Strong metal case. •Quality lab style knobs. •Comprehensive user manual. •398 x 324 x Cat. QC-1901 132mm. $ .00 Was $999.00 1000W (2000W Surge) Pure Sine Wave Inverter SAVE $100 •12VDC to 230VAC. •Electrically isolated. •Short circuit & overload protection. •400x 240x 80mm. •Optional remote control MI-5086 $49.95 SAVE $70 Was $799 899 6.5" Stainless Steel Cable Shears •Cuts up to 10mm cable. •Hardened cutting edge. Was $16.95 Cat. TH-1898 $ .95 11/13mm Ratchet Spanner SAVE $5 •Makes light work of fiddly jobs. •205mm long. •Ltd Qty Cat. TD-2141 Was $39.95 SAVE $ .95 $10 29 11 GREAT SAVINGS ON RECHARGEABLE BATTERIES AAA 650mAh Ni-MH Was Cat. SB-2444 $2.95 AAA 800mAh Ni-MH Cat. SB-1720 $3.59 AA 600mAh Ni-Cd Cat. SB-2452 $2.15 AA 1650mAh Ni-MH Cat. SB-1700 $3.95 AA 2000mAh Ni-MH Cat. SB-1706 $5.25 C 2500mAh Ni-Cd Cat. SB-2464 $6.95 C 4500mAh Ni-MH Cat. SB-2429 $12.95 D 5000mAh Ni-Cd Cat. SB-2465 $12.95 D 9000mAh Ni-MH Cat. SB-2460 $24.90 9V (8.5V) 200mAh Ni-MH Cat. SB-2467 $12.95 12V Auto Worklight •13W fluorescent. •4.5m power lead, cigarette lighter socket. Was $16.75 SAVE Cat. ST-3032 $ .75 $5 11 Backlit Travel Alarm Clock •Battery powered. •Clock, alarm, calendar, temp. Was $39.95 SAVE $10 Cat. XC-0227 $ .95 29 Matrix Alarm Clock •A clock in portrait, a calendar in landscape! •113(L) x 62(W) x 32(D)mm. •Ltd Qty Was $24.95 Cat. XC-0140 SAVE $ .95 $5 19 3-15VDC <at> 40A Lab Power Supply Now $2.60 10+ $2.30 20+ $2.00 $3.15 $2.75 $2.35 $1.90 $1.70 $1.50 $3.45 $3.15 $2.85 $4.75 $4.25 $3.75 $6.25 $5.50 $4.75 $11.35 $10.35 $9.35 $11.35 $10.35 $9.35 $22.35 $19.70 $17.70 $11.35 $10.35 $9.35 Cat. ST-3302 $ .95 Audible Reversing Sensor SAVE $25 Cat. LR-8868 $ .95 74 SAVE $50 Screwdriver Helper 4m IR Light Barrier •Dramatically increases torque reducing wear. SAVE •14g plastic $3 bottle. Was $13.95 Cat. NM-2830 $ .95 •N/O 25V <at> 3A relay output. •Up to 4m range. •Ltd Qty Was $49.95 10 SAVE $10 Cat. MP-3090 $ .00 349 Cat. AA-0342 $ .95 39 Cable Tidy Reel Pk2 30m IR Light Barrier •Control excess cabling. •Easy to use, two supplied. Was $9.95 •N/O 24V <at> 3A relay output. •Up to 30m range. •Ltd Qty Was $69.95 Cat. AA-0344 $ .95 SAVE $20 Cat. HP-1295 $ .95 49 4 LED Map Light Jumbo LCD Clock Module •Ideal for long trips at night. •Cigarette lighter powered. Was $9.95 •Displays time, date, day and temp •180(W) x 145(H) x 18(D)mm. •Ltd Qty Was $39.95 SAVE $10 Cat. ST-3059 $ .95 7 Cat. XC-0127 $ .95 29 Low Profile 12V Strobe Knightrider LED Scanners •Great car alarm addition. •65(L) x 70(W) x 25(H)mm. •Ltd Qty Was $14.95 •7 LEDs, multiple scan patterns. •12VDC powered. •Ltd Qty Red - Cat. LA-5090 Blue - Cat. LA-5091 Was $24.95 SAVE $5 34 •No more ‘bump parking’. •Flush mount sensors, drill bit included! Was $99.95 729 SAVE $2 •Amazing brightness. •Mains and car charger supplied. Was $49.95 SAVE $15 Cat. MI-5088 $ .00 HALF PRICE 2,000,000 Candle Power Spotlight •Lightweight switchmode design. •LED voltage and current displays. •Overload, temp, and voltage protection. •220(W) x 300(L) x 110(H)mm. •Weighs only 3.5kg! Was $399.00 Cat. ST-3149 $ .95 SAVE $10 9 Both Types (ea) $ .95 14 4PDT FUJITSU Relay 12V Battery Guard •Cuts load when battery voltage is low. •Max 8A load. •Ltd Qty Was $29.95 SAVE Cat. AA-0350 $ .95 $7 •12VDC. •3A NO/NC contacts. •Ltd Qty Was $14.95 SAVE $3 22 Cat. SY-4012 $ .95 11 Desk Clock/Thermo/Hygro Hiking Altimeter Electronic Compass •Quality metal construction. •Stylish analogue dials. •Ltd Qty Horizontal version - Cat. XC-0240 Vertical version - Cat. XC-0242 •Rugged aneroid mechanism. •Doubles as a barometer. Was $49.95 •Doubles as a stopwatch with lanyard. •Large liquid crystal display. Was $49.95 GREAT PRICE! Both Types (ea) $ .95 SAVE $10 29 Cat. QM-7280 $ .95 SAVE $10 Cat. QM-7282 $ .95 39 39 No rainchecks on items marked Ltd Qty. www.jaycar.com.au Online Internet Ordering Kotelyzer Gas Soldering Iron Gas Powered Glue Gun Super Drill / Engraver •1 hour fuel capacity. •High quality Japanese made. •Ltd Qty Was $69.95 Desk Lamp with Exhaust Fan •Use butane gas Cat. NaA-1020 •Uses 11mm glue sticks. SAVE $10 •Ltd Qty •High speed drill with plugpack. •Plastic drill and accessories case. Was $109.00 Cat. TD-2470 SAVE $ .00 $20 •22W circular fluorescent. •Independent lamp and fan switches. •Ltd Qty Was $139.00 SAVE $20 Was $59.95 Cat. TS-1280 $ .95 49 Antistatic Soldering Station 229 Antistatic Floor Mat 49 89 Clamp-On Automotive Tacho Cat. TH-1786 $ .00 139 •Up to 12,000 RPM, 1-8 cylinders. •LCD readout, SAVE $20 data hold. •Ltd Qty Cat. QM-1442 2003 Cat. Price $ .95 $49.95 109 16 69 Clamp Meter / DMM 12" Stainless Steel Tools •Open jaw AC clamp meter. •Basic Autoranging DMM functions. •Ltd Qty Was $94.50 Cat. QM-1545 $ .50 SAVE $15 •High quality #316 marine grade stainless steel. •Ltd Qty 12" Adjustable Spanner Cat. TH-2316 12" Slip Joint Plier Cat. TH-2324 Was $29.95 79 29 Cat. QM-3540 $ .00 •Great for component storage. •2295(W) x 355(H) x 125(D)mm overall. •Ltd Qty Was $26.95 Cat. HB-6321 $ .95 SAVE 0 $1 SAVE •0.1pF to $29.55 20,000uF range. •Includes holster. •Ltd Qty 2003 Cat. Cat. QM-1572 Price $99.50 $ .95 44 SAVE $30 33 Drawer Parts Cabinet Digital Capacitance Meter PCB Etching Tank •Suits PCBs up to 200 x 250mm. •Thin design means less SAVE $5 solution is Cat. HP-9530 required. $ .95 Was $49.95 •Temperature controlled. •Digital display. SAVE •Lightweight pencil. $40.95 •Large LED readout. Cat. TS-1440 •Japanese made. .00 2003 Cat. Price $269.95 $ •A must for static sensitive handling. •2m x 1m x 2mm thick. Was $169.00 SAVE $30 Cat. TH-1998 $ .95 SAVE $10 Both Types (ea) $ .95 19 19" Rack Panels Modular Tool Kit 7.2VDC 168g/cm Motor Stepper Motor - PC Interface •Ideal for building patch bays and more. •Ltd Qty SAVE 2U $4 Was $21.25 SAVE 3U $6 Was $27.00 •Includes crimp tool, wire cutter, punch down tool, many modular plugs and boots. •Ltd Qty Was $84.95 Cat. TD-2090 $ .95 SAVE $20 •11,000RPM. •1/8" (3.175mm) drive shaft. •Ltd Qty Was $12.95 •Suits 4 pole motors between 5-18VDC <at> 2A. •Control via parallel port. •Ltd Qty Was $49.95 SAVE $10 Cat. HB-5405 $ .25 17 Cat. HB-5403 $ .00 21 NEW HARDCORE ELECTRONICS! Thermoelectric (Peltier) Modules Orange White Cat. ZD-0401 $14.95 Light Dimmer •400VA, inc wall plate. DIY Coax Tool Cat. TH-1875 $ .95 19 Screw Type F Connector Tool for RG6 Backlit Dot Matrix LCD Module •Make light work of twist on F connectors. •Also separates shield from insulation. •2 lines, 16 characters. •Display size 64 x 16mm. Cat. QP-5516 $ .95 28 Cat. TH-1876 $ .95 9 Cat. ZD-0403 $16.95 Cat. ZD-0404 $16.95 Desk Grommet •60mm cut out, black. Cat. PS-4082 $ .95 29 18 0 0 0 2 2 8 8 8 Freecall For Orders Cat. HP-1228 $ .95 9 39 •Cutter, stripper, crimper. •Suits RG6, RG58, RG59. •Intermittent use only. 2 1W Luxeon LEDs Cat. AA-0352 $ .95 You may see a few gadgets on the front page, but this section is dedicated to what’s new for the Hardcore Enthusiast. Cat. PS-4165 $ .95 •Up to 120 Lumens per LED! •100,000 hours life expectancy. •Fully dimmable. •Superior ESD protection. •New Luxeon 1W LED Green driver kit on back page! Cat. ZD-0402 $16.95 Cat. ZD-0400 $14.95 7 •2 pin oval to alligator clips to suit POWERTECH plugpacks. 11 14 17 Blue Cat. YM-2714 $ .95 Alligator Lead for Plugpacks •Solid state devices that can cool -27°C or heat +100°C to ambient. •Require heatsinks, fans, and 12-15VDC. $ .95 Cat. ZP-9100 33W 4A $ .95 Cat. ZP-9102 54W 6A $ .95 Cat. ZP-9104 68W 8A Red SAVE $5 64 Covered Screw Terminals •Clear covers protect from shorting. •300V <at> 25A rating, 12-22AWG cable size. •9.5mm pitch. PCB Mount 4 Way - HM-3162 Panel Mount 4 Way - HM-3166 PCB Mount 6 Way - HM-3164 Panel Mount 6 Way - HM-3168 12VDC Reversible Gearhead Motors •4.5-18VDC operating voltage. •Forward or reverse operation. 2.1kg/cm Torque <at> 70RPM 4 Way (ea) $ .40 3 6 Way (ea) $ .70 No rainchecks on items marked Ltd Qty. 4 Cat. YG-2732 $ .95 12 12kg/cm Torque <at> 36RPM Cat. YG-2734 $ .95 19 3V to 9VDC Converter Kit Interior Light Delay Kit MkII •Ref: Silicon Chip March 2004. •Use AA, C and D cells in place of 9V batteries. •Includes PCB and electronic components. •Ref: Silicon Chip June 2004. •Light fade-out, simple wiring even for modern cars. •Includes PCB, case and electronic components. ‘Smart’ Fuel Mixture Display Kit for Cars •Ref: SC April 2004. •10 LED indication with lean out alarm. Cat. KC-5374 $ .95 Digital Instrument Display Kit Emergency Brake Light Trigger Kit •Ref: SC March 2004. •Triggers brake lights with quick throttle lifts. Pro Series III Stereo Power Amplifier Kit Mono Power Amp Kit Cat. KC-5201 $ .95 69 $4 •Trips a buzzer at preset low voltage. Was $13.95 Cat. KF-4010 $ .95 Ultrasonic Proximity Detector Kit •Save $$$ over commercial equivalents. Was $24.95 SAVE $6 Cat. KA-1760 $ .00 549 •Ref: SC Aug 2003. •Controls software via the serial port with universal remotes. Was $39.95 SAVE $8 PIC Programmer / Checking Board Kit •Ref: SC March 2001. •Ideal for developers. Was $99.95 Cat. KC-5307 SAVE $ .95 $30 Fibre Optic Communication Kit •A great introduction to fibre optics. Was $45.95 Cat. KF-4810 SAVE $ .95 $14 31 9 Cat. KG-9158 $ .95 18 Smart Slave Flash Trigger Kit •Ref: SC July 2003. •Automatically trigger an external flash. SAVE Cat. KC-5364 •Ltd Qty $7 $ .95 Was $29.95 22 2A DC - DC Converter Kit IR Remote Control Kit for PCs 69 12V Low Voltage Alarm Kit SAVE 39 49 24 •Ref: SC April 1996. SAVE •175WRMS <at> 4Ω, $26 •115WRMS <at> 8Ω. •Heatsink not supplied. Was $95.95 10 Ch IR Receiver Kit •Ref: SC Feb 2002. •10 low current outputs, works with universal remotes. •Ltd Qty SAVE Cat. KC-5326 $10 Was $49.95 $ .95 •Ref: SC Aug/Sept 2003. •Digital readout of an analogue sensor. •Ltd Qty Was $59.95 Cat. KC-5365 $ .95 SAVE $10 Cat. KC-5373 $ .95 •Ref: Electronics Australia Feb/Mar 1994. •185WRMS <at> 8Ω continuous. •255WRMS <at> 4Ω continuous. •0.005% THD <at> 100WRMS into 8Ω •>100dB signal to noise <at> 100WRMS into 8Ω •Includes FREE soldering iron! •Includes PCBs, case, silk screened and punched panels, SAVE toroidal transformers, and all wiring hardware. $50 Was $599.00 NEW SOUTH WALES Albury Ph (02) 6021 6788 Bankstown Ph (02) 9709 2822 Bondi Junction Ph (02) 9369 3899 Brookvale Ph (02) 9905 4130 Campbelltown Ph (02) 4620 7155 Erina Ph (02) 4365 3433 Newcastle Ph (02) 4965 3799 Parramatta Ph (02) 9683 3377 Penrith Ph (02) 4721 8337 Silverwater Ph (02) 9741 8557 St. Leonards Ph (02) 9439 4799 Sydney City Ph (02) 9267 1614 Taren Point Ph (02) 9531 7033 Wollongong Ph (02) 4226 7089 VICTORIA Coburg Ph (03) 9384 1811 Frankston Ph (03) 9781 4100 Geelong Ph (03) 5221 5800 Melbourne Ph (03) 9663 2030 Ringwood Ph (03) 9870 9053 Springvale Ph (03) 9547 1022 QUEENSLAND Aspley Ph (07) 3863 0099 Brisbane - Woolloongabba Ph (07) 3393 0777 Gold Coast - Mermaid Beach Ph (07) 5526 6722 Townsville Ph (07) 4772 5022 Underwood Ph (07) 3841 4888 AUSTRALIAN CAPITAL TERRITORY Canberra Ph (02) 6239 1801 TASMANIA Hobart Ph (03) 6272 9955 SOUTH AUSTRALIA Adelaide Ph (08) 8231 7355 Clovelly Park Ph (08) 8276 6901 WESTERN AUSTRALIA Perth Ph (08) 9328 8252 NEW ZEALAND Newmarket - Auckland Ph (09) 377 6421 Glenfield - Auckland Ph (09) 444 4628 Wellington Ph (04) 801 9005 Christchurch Ph (03) 379 1662 Freecall Orders Ph 0800 452 9227 29 99 27 YOUR LOCAL JAYCAR STORE Cat. KC-5389 $ .95 Cat. KC-5388 $ .95 18 14 •Ref: Silicon Chip May 2004. •Power 1, 3, and 5W LEDs from 12V. •Includes PCB and electronic components. •Ref: Silicon Chip May 2004. •Get the best possible picture from your home theatre. •Includes PCB, case, screened & punched panels, plugpack & electronic components. Cat. KC-5392 $ .95 Cat. KC-5391 $ .95 Luxeon Star LED Driver Kit Component Video to RGB Converter Kit Raucous Alarm Kit •Ref: SC Jan 2002. •Emits an extremely loud tones when triggered. •Ltd Qty Was $34.95 Cat. KC-5327 $ .95 SAVE $10 24 •Ref: SC June 2003. •Steps 12V up to 13.8-24V <at> up to 2A. Was $49.95 Cat. KC-5366 $ .95 31 SAVE $10 Cat. KG-9196 $ .95 39 39 AV Distribution Amp Kit AVR ISP Serial •Ref: SC Nov 2001. Programmer Kit •6 way split with no loss. Was $139.95 SAVE $40 Cat. KC-5320 $ .95 99 •Ref: SC Oct 2002. •Program in circuit with downloadable software. Was $45.00 Cat. KC-5340 $ .00 35 1W Audio Amp Kit Infrared Floodlight Kit •32 IR LEDs for night viewing with CCD cameras. Was $24.95 Cat. KG-9068 SAVE $ .95 $6 Cat. KG-9032 $ .95 SAVE $2 5 Mini Voice Operated Relay Kit Knight Rider LED Scanner Kit MkII •Ref: SC May 1996. •16 LEDs scanning back and forth. Was $22.95 SAVE $5 Cat. KC-5204 $ .95 17 •Allows you to hear noises far away. Was $24.95 SAVE $5 18 •Ref: SC Sept 1994. •3 second release time. Was $14.95 Cat. KC-5172 SAVE $ .95 $3 11 Super Ear Kit Cat. KG-9024 $ .95 19 •Ref: EA May 1998. •Assists people who have trouble hearing high frequencies. Was $24.95 Cat. KA-1809 SAVE $ .95 $5 19 MAIL ORDERS - FREE POST TO: Reply Paid 6424. Jaycar Techstore Mail Orders. PO Box 6424, Silverwater NSW 1811 RAINCHECKS: If a currently advertised item is sold out or unavailable, we will gladly issue you with a 'raincheck'. You can then buy the item at the advertised price as soon as it is available. Naturally, rainchecks to not apply to discontinued, limited stock, or clearance items. See in store for full details. No rainchecks on items marked Ltd Qty. SAVE $10 •1W <at> 8Ω on a board 28mm squared. Was $7.95 50m IR Light Barrier Kit Parabolic •Triggers relay Mic Kit when beam is broken. Was $49.95 Cat. KC-5358 $ .95 SAVE $10 www.jaycar.com.au Online Internet Ordering PRICES VALID TO 3OTH JUNE 2004 SILICON CHIP siliconchip.com.au YOUR DETAILS NEED PCBs? Order Form/Tax Invoice You can get the latest PCBs and micros direct from SILICON CHIP! See p100 for full details . . . Your Name_________________________________________________________ Silicon Chip Publications Pty Ltd ABN 49 003 205 490 PO BOX 139, COLLAROY NSW 2097 email: silicon<at>siliconchip.com.au Phone (02) 9939 3295 Fax (02) 9939 2648 This form may be photocopied without infringing copyright. 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SILICON CHIP MAGAZINE BINDERS q OR FAX (24/7) This form (or a photocopy) to (02) 9939 2648 with all details AMATEUR SCIENTIST CD NEWEST Version 4.0............................................. $62.00 AUDIO POWER AMPLIFIER DESIGN – SELF ................................................. $81.00 BUILD YOUR OWN ELECTRIC MOTORCYCLE ... ............................................ $40.00 DVD PLAYERS AND DRIVES ........................................................................ $71.00 ELECTRIC MOTORS AND DRIVES.................................................................. $51.00 NEWNES GUIDE TV & VIDEO TECHNOLOGY................................................. $49.00 OP AMPS FOR EVERYONE.......................................................................... $100. 00 PIC IN PRACTICE........................................................................................... $60.00 PIC MICROCONTROLLERS - KNOW IT ALL................................................. $83.00 PIC MICROCONTROLLER - PERSONAL INTRO COURSE............................... $60.00 PRACT. 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Books: Aust. $10 per order; NZ: $AU12 per book; Elsewhere $AU18 per book OR PAYPAL (24/7) OR Use PayPal to pay silicon<at>siliconchip.com.au PHONE – (9-5, Mon-Fri) Call (02) 9939 3295 with your credit card details *ALL ITEMS SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES IN AUSTRALIAN DOLLARS AND INCLUDE GST WHERE APPLICABLE. OR MAIL This form to PO Box 139, Collaroy NSW 2097 June 2004  53 6/04 SERVICEMAN'S LOG TV sets that buzz and hum This month has been fairly routine, with lots of little repairs, for which I was grateful. It meant that I could plough along and make a little money for a change, without testing the grey matter too much. One of the few interesting jobs this month was a Philips 29PT5683/79R TV set, which uses the A8.0 chassis. The client was complaining that the set was dead and buzzing! Well, to me, that’s a contradiction in terms – the set can be either dead or buzzing but not both. Or perhaps it was buzzing first and then died? Anyway, it was the latter. The usual 2200pF 2kV ceramic capacitor (C2168) on the collector of the output transistor had burnt out and after negotiating the all-encompassing plastic framework, I replaced it with a 6kV version. However, the set was still dead, with the red LED flashing error code 1. This meant that the protection mode was on and that there was a fault in the x-ray, east-west correction and/ or vertical deflection circuits. The earthy end of C2618 went to the EW panel via pin 4 of M61/E61 and then via a collection of coils to FET7680 (STP16NE06FP). Access to this module wasn’t easy and it had to be removed completely before I could remove the FET which was indeed short circuit. Ordering and fitting a replacement FET was the easy part. Reassembling the plastic frame was the difficult bit and took most of the time. And that fixed the fault. All that remained was to reset the fault codes via the EEPROM and the set was ready to go home. The humming National An ancient National TC2086 with a PBA-M14 chassis came into the workshop. It’s only sign of life was a humming noise, so I removed the back and began checking voltages. After establishing that the B+ rail was OK, I soon discovered that the horizontal drive transistor collector voltage was all over the place. And this turned out to be due to dry joints on the horizontal drive transformer (T501). This in itself is unremarkable but had this identical fault occurred in something like a Sony BG-1S or G3F, it would have destroyed the line output transistor. The fact that it survived is probably due to the fact that many older sets were “over-designed”. For the same reason, I also wonder how many current sets will last as long as the older designs, such as the Rank Arenas, etc of 1975. The SSB strikes again I have written before about the Philips A10 chassis TV sets and the problems with their Small Signal Panel Board. Well, it seems that the problems with this board can also extend to the later EM1A chassis! For example, I had an 18-month old 29PT8419/79R come in with no less than six faults: no colour off air (but OK with AV), no pincushion correction, no Teletext, no picture-in-picture or double window, intermittent no remote control, and intermittent no control functions on the set itself when it got hot. Ironically, the set showed no error codes at all! Replacing the SSB fixed all the problems. However, it should be said that the SSB for this set is much sturdier than its predecessors. It’s mounted inside a metal cage and the connector is the same type as used for SDRAM modules in modern PCs, only with additional plastic supports to suit its much larger size. After fitting the exchange module, all the geometry and other controls, plus various options, have to be reset. This all takes time of course and is fiddly. The Service Alignment Mode, by the way, is still accessed by keying in 062596 plus the OSD Index i+ button on the remote. A simple repair We recently had a 2003 Indian-made Panasonic TC-21Z88A television using an MX-5Z chassis come in under 54  Silicon Chip siliconchip.com.au Items Covered This Month • • • • • • • • • Philips 29PT5683/79R TV set (A8-0 chassis) National TC2086 TV set (PBAM14 chassis) Philips 29PT8419/79R TV set (EM1A chassis) Panasonic TC-21Z88A TV set (MX-5Z chassis) Toshiba 289D8A TV set Philips 29PT2152/79 TV set (L01.1A chassis) Philips Flat TV 17PF9945T2 (LC03 chassis) Panasonic TC-68GS90A TV set (M19 chassis) Philips 32PW8807/79R TV set (EM3 chassis) warranty. This set had an east-west fault with excessive width and it was showing the CHk mode symbol in the top righthand corner. In the adjust mode, the width could change its value on the On-Screen Display (OSD). However, the width itself wasn’t changing geometrically. I replaced the EEPROM (IC1103, C3EBFC000025) and then realigned the controls to complete a fairly simple repair. The blue Toshiba A customer dropped off a Toshiba 289D8A TV set, complaining of a blue screen but no picture. This 1990 set was different from the more usual 289X8M models we used to see but it took some time for me to realise this. The reason why the raster was blue was because the greyscale was so far out. This was soon corrected to a black raster by making the appropriate adjustments. However, there was still no picture – at least not initially. Vibrating or tapping the set seemed to make no difference but then the picture appeared as the set warmed up. In fact, once it had completely warmed up, it was very hard to get it to play up at all. I examined the main chassis very carefully, changing any well-known troublesome capacitors such as C303 (1µF) and C317 (2.2µF) in the vertical timebase (hopefully affecting the blanking and muting circuits) and siliconchip.com.au soldering any suspicious dry joints. Unfortunately, nothing I did was having any effect. Anyway, to cut a long story short, I found that the difference between this set and the 289X8M models was that this one had a Teletext module. And, as I quickly discovered, the three large ICs and the connection socket were riddled with dry joints (and well hidden by a shielding plate). The Teletext module had to be desoldered to get it out for access but once the job was done, the fault was fixed. A weird picture Another Philips 29PT2152/79 TV (L01.1A chassis) came in with the weirdest looking picture. As far as the client was concerned, the picture was “all broken up” but it really was hard to describe. However, it looked as though it had a line interlace problem – there were multiple irregular lines all over the two-thirds scanned screen, with vertical foldover. A quick check with an oscilloscope showed that the vertical drive output from the jungle IC (IC7200) was distorted. Unfortunately, the service manual is hard to use, because you constantly have to look up “Diversity Tables” to find the values of the components for your model (if fitted). Anyway, after replacing IC7200 (TDA9565H/N1/4), the waveforms from pins 16 & 17 (S3 & S4) were OK all the way to pins 1 & 3 of the vertical output stage (IC7471, TDA8359J). I replaced this IC as well but it made no difference. I then checked the two voltage rails to pins 3 & 6. The former (13V) was OK but the latter (Vlot Aux +50V) was low at 45V, with significant ripple. Next, I checked C2487 (47µF) and swapped L5472 from another chassis. This made no difference, so I concentrated on the IC itself, especially around the vertical output circuitry. In particular, I checked the components around pins 7, 9 & 4, along with the waveforms, but it was hard to pinpoint the culprit. June 2004  55 Serviceman’s Log – continued In the end, it was the output waveforms that provided the vital clue. They were quite distorted, with significant ringing, which led me to suspect resistors R3477 and R3478 (150Ω) in series across the deflection yoke. They both measured high and replacing them fixed the fault! Philips LCD TV One difficult problem we faced recently involved a Philips Flat TV – model 17PF9945T2 with an LC03 chassis. According to the client, this beautiful 17-inch LCD TV was taking a very long time to come on and was taking even longer to give sound and picture though it was quicker when connected to a digital set-top box (or digibox). The problem was getting it to play up for us. Heating, cooling and vibration tests produced no measurable effects. However, being an authorised Philips Service Centre, we are privileged to receive Service Information Updates and we had no less than three such updates for similar symptoms. The first update says to check that the wires from CN2, CN3, CN4 and CN5 on the Inverter Board are well connected via the four connectors to the LCD panel. The second update says to check the flexible cable for pin damage. And the third update lists two modifications: (1) R49 (10kΩ) is 56  Silicon Chip changed to 3kΩ (bias to Q8); and (2) R29 (0.33Ω) is changed to a link (5V supply to IC U1). We tested it for a another week and it is now back with the client. A frustrating job Of course, there’s always one job that goes wrong when everything else seems to be going so swimmingly. The set concerned was a 1999 Panasonic TC-68GS90A using an M19 chassis and it came in DOA (as in “dead on arrival”). Apparently the cause was due to a power surge during a storm. It wasn’t hard to diagnose the basic problem – there was no voltage to the power standby relay (RL801) and diode D871 had been blown apart, with black marks going to capacitor C803 which had also blown. I hadn’t seen this chassis before and was grateful to have the service manual – that is, until I discovered that the guy who drew the circuit must have been half-asleep at the time because of all the glaring errors in it. For example, the bridge rectifier (D801) is not shown at all, while D809 is only partially shown and the circuit around it is incorrect. Fortunately, this didn’t really concern me at this stage, as I was concerned only with a simple standby switchmode power supply that controlled the relay. What did concern me was what voltage to expect from this power supply. The circuit keeps referring to an “RMCN-8v”, which I initially took to read as an 8V supply for the remote control receiver on the front panel (ie, the G Board and there is another switched 12V rail to this). However, relay RL801 is a 12V relay (or at least, this is what is stamped on the component casing), so it cannot be an 8V rail. Delving further into the service manual, I found on page 12-70, under adjustment procedure, that TPD35 (the output from this standby supply) is normally 12V but can range from 10-14V. Things were beginning to get foggy already but not to worry, as my DMM read 0V, so all I had to do was improve on that! This power supply is very simple, with a maximum of 35 components. It consists of a negative half-wave supply which is fed into transformer T801 and from there to a 3-pin IC (FET IC881, MIP0210SYITV). Pin 2 of this device goes to –ve, while pin 1 (control) is supplied by a rectified voltage from a separate winding on the transformer. The secondary of the transformer feeds diode D890 which is turn supplies the voltage to relay RL801. It also feed an optocoupler which uses an 8.2V zener diode (D892) and diode D891 to give a 9V (approx.) reference. The feedback to the control pin is first via the separate power supply winding and then the optocoupler. What could be easier than that? A few quick checks showed that antisurge resistor R881 (1.2Ω, 2W) was open circuit, while C803 and the IC FET were both short circuit. I replaced all three, expecting an easy result but not so. The circuit just wouldn’t do its thing and although I did a thorough check of the 35-odd components using siliconchip.com.au a multimeter, I couldn’t fault it at all. By now, I suspected that transformer T881 was the culprit. I mentioned this to two other colleagues and they both checked the circuit out too. In the process, all the electrolytics were changed, along with the optocoupler, but we were getting nowhere. In the end, a new transformer was ordered in and duly fitted. This was a good move, as the power supply now began to pulsate slowly, but it didn’t have enough “herbs” to trip the relay. We tried a variety of other loads and almost every part was either retested out of circuit or replaced but it had us beaten. Between us, we have about 80 years worth of experience on TV repairs, so this was particularly galling. I’m beginning to think I’m getting “past it”. Anyway, the set was temporarily put aside while we got on with jobs until, by accident, I discovered another D Board (TNPH0165) half-stripped of components in a corner of the workshop. All I needed was another identical board to make comparisons – this was the answer to a maiden’s prayers (well, to my prayers, anyway)! I reinstalled the missing parts on the board just to make this circuit work, which fortunately it did. Now I could measure the voltages I should expect at various points and hopefully I would be home and hosed. Well, it was not to be. Comparing the voltages between the pulsating circuit and this one really only highlighted one difference – one was pulsating and the other wasn’t. The voltages were almost the same except, of course, that they were varying in the faulty one. Disgusted with myself, I tried to make sense of the figures. The only slight clue I had was the voltage supply for the optocoupler on the primary (hot) side. Before the transformer was changed, there was no DC voltage on the cathode of D883. Afterwards, it was pulsating at about 6V but on the good supply, it was rock steady 7.38V. This diode (D883) has an 820pF capacitor (C877) in parallel with it, along with a 0.1µF smoothing capacitor (C887). This arrangement then directly feeds the transistor inside the optocoupler (D884). I decided to replace the lot with new components and see if anything happened. If it did, I could then analyse the parts afterwards to find out which one was faulty. Of course, nothing changed – the parts were all OK. And then it hit me! In mitigation, I have to say that the circuit board labelling (the layout isn’t shown in the service manual) is not the best. It’s done in shellac white paint and it’s all too easy to confuse the numbers C877 and C887 at the best of times. Yes, that was it – I was comparing the two boards together, side by side, when it suddenly dawned on me that the 0.1µF and the 820pF capacitors had been interchanged when they were replaced earlier on. Switching them back made all the difference and the set burst into life, with the relay operating correctly. Now I don’t want to point the finger but I’m sure it wasn’t me who was responsible! Let the sound be with you We had another late model Philips TV come in under warranty, with what looked like a simple fault. It was a 2001 32PW8807/79R employing an EM3E chassis and the siliconchip.com.au June 2004  57 Serviceman’s Log – continued fault was no sound. I started by measuring the righthand loudspeaker and it was OK at 8Ω. I then checked the sound signals into the Small Signal Board and found it was there all the way to pins 10 & 18 of the audio output IC (IC7700, TDA7490). Before replacing the now suspect audio output IC, I checked all the 58  Silicon Chip voltages on all its pins against those shown on the circuit diagram. Everything, including the supply rails, was spot on except for the “Standby-Mute” pin (pin 6), which measured 0V. This pin is controlled by six transistors, which are in turn controlled by “Sound-Enable” (from the SSB), “POR” Power-On-Reset (from the 11V line deflection power supply), “Protection 1” (from IC7700’s output) and “Standby-Mute” (from pin 6 of IC7702). I started checking this circuit by desoldering pin 6 of IC7700 and measuring the voltage that was coming in – it was still 0). Similarly, I tried desoldering pin 6 of IC7702. I then checked all six surface-mounted transistors with an ohmmeter in circuit and these measured OK. Next, I turned my attention to transistor 7707 (BC847B). This was switched on by transistor 7706 (BC857B) via R3714 (47kΩ). However, there was no voltage on the collector of this latter transistor – so where was the 0.6V on transistor 7707’s base coming from? I tried shorting out the base and emitter of 7707 and the sound was restored. I then removed transistor 7707 and sound was still there. A quick check showed that this transistor was leaky and replacing it fixed the sound – well, nearly! Sound was now only coming out of one speaker – the righthand one. However, it was distorted and substituting another speaker showed that the distortion was coming from the IC7700. I also checked the lefthand loudspeaker and it was open circuit. Replacing the lefthand loudspeaker restored sound to that channel, while replacing the IC, which I originally suspected, fixed the distortion as well. I guess I should have gone with “the SC force” earlier on! siliconchip.com.au Is your fridge or freezer door often left open for too long? Or does it sometimes not close properly? Ensure it’s closed when it should be by building this nifty Fridge Alarm. FRIDGE DOOR-OPEN ALARM By JOHN CLARKE A REFRIGERATOR OR freezer door that is left open or ajar may cause the food contents to spoil. In some cases, the internal temperature of the fridge or freezer will be maintained if the refrigeration system can cope with the open door. But without the door sealing in the cold air, it may be a losing battle. Running costs will certainly rise. Typically, refrigerators and freezers are in constant use in the summer months and so it is important to ensure that the door is not open for any longer than is necessary. Otherwise the fridge or freezer will not be able to keep the siliconchip.com.au contents cool. And it will cost more money to needlessly run the fridge’s compressor in a futile effort to keep the contents cool. Even the most diligent fridge user may sometimes leave the door of the fridge or freezer open without realising it. And tilting the fridge or freezer slightly backward so that the door will fall shut is not completely fool proof as there may be an obstruction inside the door. The obstruction could be because an item inside the compartment has moved or fallen over or because the compartment is too full. This is where the Fridge Alarm is useful. It warns when the door of the refrigerator or freezer is left open for longer than a preset time period. It is great for indicating when someone is standing with the door open for too long and a real asset in warning when the door looks shut but is still partially ajar. The fridge alarm operates by detecting when any light enters the compartment area. Therefore it is just as useful for freezers (which normally do not have a light) as it is for fridges (which normally do). As long as there is some ambient light which the alarm can react to, it will operate. June 2004  59 door is left ajar since the internal light is switched off via the door switch before the door closes. The circuit You don’t have to house it in a transparent box, as we did . . . but if you don’t, you’ll need another hole in the appropriate place on the box wall so light can strike the LDR inside. The alarm will sound if the light is present for longer than the preset period and will continue to sound until the door is closed. In practice, the preset period is adjusted so that in normal use the alarm will not sound. It will sound when the door is left wide open for too long or if left slightly ajar. Commercial coolrooms and freezers While the Fridge Alarm is primarily intended for domestic fridges, it has its applications for large (ie walk-in) commercial coolrooms and freezers. If you think that your fridge at home costs a lot of money to run, try paying the bill for one of those walk-in models that clubs and restaurants use. And in a busy club or restaurant, it is very common for staff to leave the door open. Because the door is so large, bulk cold escapes very quickly. If the walk-in coolroom or freezer has a door-operated light, the Fridge Alarm will work in exactly the same way as in a domestic fridge. If the light switch is manual (as many are), it will warn that the light has been left on. And if it doesn’t have a light inside, you could set it up near the doorway and have the alarm triggered by natural light from outside. Note that the alarm cannot be used 60  Silicon Chip with display refrigerators or freezers that have a glass door. Does the light really go off? Do you or members of your family have doubts whether the fridge light really goes off when the door is closed? Does the little man in the fridge really do his job? Or is he sitting in there goofing off? This Fridge Alarm will finally dispel any doubts on this score. If you open the door and can hear the alarm sounding immediately, it means that the light has remained on while the door was closed. Disbelievers will say it’s a fault in the alarm unit itself rather than the light remaining on. Perhaps we will never know. The Fridge Alarm is battery operated and so does not need to be connected to any wiring inside the compartment. It comprises a small transparent box with the alarm circuit and battery housed inside. The box is placed within the freezer or refrigerator near to the door opening. In this way it can monitor both the light from the internal lamp and also light entering from the outside. Monitoring light from the outside is important since it allows detection of the door being left only slightly ajar. Monitoring the internal light only will not indicate when the Circuitry for the Fridge Alarm comprises a single IC package, a Light Dependent Resistor (LDR), a siren plus a few resistors, diodes and capacitors. The low temperature operation has meant that all components need to be rated for sub zero temperatures. The IC is rated to –40° C, while the piezo siren is rated to –20°C. Other components such as the capacitors, diodes, LDR and resistors will operate to below -20°C. The battery is specified as an alkaline type to provide the necessary current at lower temperatures. And current drain is not very high. When the circuit is in the dark, quiescent current is typically less than 6µA and this low current will prevent the battery discharging before the end of its shelf life. Current consumption when the alarm is sounding is a mere 2mA. Operation of the alarm relies upon light detection using the LDR. This device has low resistance below 10kΩ when there is sufficient light on its surface and a high resistance of more than 1MΩ when in darkness. We use this change in resistance in a voltage divider with a 1MΩ trimpot and a 150kΩ resistor across the 9V supply. Voltage across the LDR is monitored at the pin 1 input of Schmitt trigger IC1a. IC1a has two threshold voltages which are nominally 1/3rd the supply and 2/3rd the supply. These thresholds are 3V and 6V with a 9V supply. If voltage at pin 1 is 6V or more then the output at pin 2 will be 0V. If the pin 1 voltage falls below 3V, then the output at pin 2 will be at 9V. In the dark When the fridge or freezer door is closed, the LDR is in complete darkness and so it has a high resistance. The total resistance of the 150kΩ resistor and VR1 is now smaller than the LDR resistance and this causes the voltage at pin 1 to rise above the upper threshold of the Schmitt trigger. As a result, the output at pin 2 will be at 0V. Capacitor C1 is held at 0V via diode D1 and the series connected 2.2kΩ resistor. Schmitt trigger IC1b monitors the voltage across C1 at its pin 3 input. Since pin 3 is at 0V, pin 4 is at 9V. siliconchip.com.au Fig.1: the circuit is basically a light trigger, timer, oscillator and piezo driver. It’s all based on one low-cost IC. Diode D2 and the series 2.2kΩ resistor pull the pin 5 input to IC1c close to 9V and so pin 6 is at 0V. The output of IC1c drives paralleled Schmitt triggers IC1d, IC1e and IC1f and since IC1c’s output is at 0V, the paralleled Schmitt outputs are at 9V. Outputs of IC1d, IC1e and IC1f at pins 8, 10 and 12 respectively drive the (-) side of the piezo siren. At this stage the siren will not be driven since the (+) terminal of the piezo siren connects to the 9V supply and the (-) terminal is at 9V. This is the Fridge Alarm’s normal state when in darkness. Current drain from the battery is very low and is caused by several current paths. The first is the current flow through the LDR, VR1 and the 150kΩ resistor. The LDR will be about 2MΩ or more in darkness and the current will be less than 4.5µA for this part of the circuit. Another current path is through diode D2, and the series connected 2.2kΩ resistor and the 10MΩ resistor connected between pins 5 and 6 of IC1c. Current flows because pin 4 of IC1b is at 9V and the pin 6 output of IC1c is at 0V. Current drain here is less than 1µA. The final current drain is the supply to IC1 itself and the 100µF capacitor across the supply (after D4). For that reason we specify that both 100µF capacitors should be low-leakage types. IC1 is a CMOS device that has a very low supply current of typically below .05µA. The total current drain is therefore expected to be around 6-7µA. Door open When the fridge or freezer door is opened, the resistance of the LDR drops and this pulls pin 1 of IC1a below its lower threshold and pin 2 goes to 9V. Diode D1 becomes reverse biased and so capacitor C1 now begins to charge via the 9V at pin 2 and through the 100kΩ resistor and VR2 trimpot. Charging time for C1 can be adjusted using VR2 which allows timing values from around 10s through to 100s. When the capacitor voltage reaches about 6V, the voltage becomes more than the positive going threshold for IC1b, and the output goes to 0V. Diode D2 is now reverse biased and the already charged capacitor C2 now discharges via the 10MΩ resistor between pin 5 and pin 6. When C2 discharges to about 3V, it reaches the lower threshold voltage for Schmitt trigger IC1c and its output at pin 6 goes to 9V. Capacitor C2 now charges Fig.2: there’s not much you can get back-to-front on the PC board – just the IC, diodes, electrolytic capacitors and the piezo siren (and of course the battery snap wires). The LDR is not polarised. Use this component layout along with the photo at right when putting it together. siliconchip.com.au June 2004  61 Power for the circuit is obtained from a 9V battery. Diode D4 provides reverse polarity protection if the battery is connected in reverse. A 100µF capacitor decouples the supply and provides energy for the piezo siren when it draws bursts of current. Construction The plastic box needs to have two holes drilled in the bottom (for the mounting pillars) and one in the top (to let the sound out). Here’s how it all goes together in the box. It’s a nice snug fit with the battery held in place by the PC board. up via the 1MΩ resistor and diode D3. This charge time is about 10 times faster than the discharge time and when the voltage reaches the upper threshold of IC1c’s input the output at pin 6 goes to 0V. IC1c thus forms a burst oscillator where the output is at 9V for only a short time compared to its low output period. When IC1c’s output is at 9V, the resulting 0V output of IC1d, IC1e and IC1f drive the piezo siren with a 9V supply and the siren sounds. When IC1c’s output goes to 0V, the IC1d, IC1e and IC1f inverter outputs are at 9V and the siren is off. This sequence of signal drives the siren with bursts of sound. When the refrigerator or freezer door closes again, the LDR goes to a high value of resistance. Thus pin 1 of IC1a 62  Silicon Chip rises toward the upper threshold of the Schmitt trigger. This may take several seconds because the dark resistance of the LDR slowly increases over time until it reaches its ultimate value. It is a rather slow responding device to low ambient light levels. VR1 is included to adjust the sensitivity to darkness. It is adjusted so that the alarm will still operate even with very low light levels which are typical when the door of the fridge or freezer are left ajar. Ultimately, when in complete darkness, pin 1 of IC1a will reach 6V and the IC1a output will go low to discharge C1. The resulting 9V at pin 4 of IC1b charges capacitor C2 via D2 and the 2.2kΩ resistor. This holds the burst oscillator off with the pin 6 output at 0V. Parts for the Refrigerator Alarm are assembled on a PC board coded 03206041 and measuring 78 x 32mm. The PC board is mounted inside a translucent box measuring 83 x 54 x 31mm. The box can either be uncoloured or tinted. We used the new blue style case available from Jaycar and Altronics. Begin construction by checking the PC board for any shorts between tracks or breaks in the copper. Check hole sizes and file out the corner section of the PC board on two corners if not already removed. These cutouts are required to allow access for the internal pillars in the box. The mounting holes need to be 3mm in diameter. Now install the resistors, diodes and IC1. This IC and the diodes must be oriented as shown. Resistors are marked with a colour code and these are shown in the accompanying resistor code table. You can use this table as a guide to selecting each value. Also it is a good idea to check the value with a digital multimeter. Install the two trim pots VR1 and VR2. These have a 1MΩ resistance and may have a 105 marking on the side. The two 100μF electrolytic capacitors should be low leakage types, as previously mentioned, and must be oriented with the polarity shown in the overlay diagram. Place the PC stakes at the 9V battery lead connection points and in the holes allocated for the piezo siren. The siren is mounted by soldering its leads to the PC stakes. Note that the PC stakes and siren leads will need to be shortened so that when installed the top of the siren is 14mm above the top of the PC board. The LDR is mounted by inserting its leads into the PC board leaving a 10mm length between the LDR and PC board. After soldering, the LDR is carefully bent over at right angles to face the edge of the PC board. The PC board is mounted within the case using two 10mm long spacers to support the outside edge of the PC siliconchip.com.au Parts List 1 PC board coded 03206041, 78 x 32mm 1 UB5 translucent box, 83 x 54 x 31mm 1 panel label 1 piezo siren, 12mm diameter, 7.6mm pin spacing (-20°C operation) (Jaycar AB3459) 1 9V alkaline battery 1 9V battery clip lead 1 LDR with greater than 1MΩ dark resistance (Jaycar RD3485, Altronics Z1619 or similar) 2 10mm M3 tapped spacers 2 M3 x 6mm countersunk screws 2 M3 x 6mm pan head screws 4 PC stakes Semiconductors 1 MM74C14, CD40106BC (-40°C to 85°C) hex Schmitt trigger (IC1) 4 1N914, 1N4148 diodes (D1-D4) Capacitors 2 100µF 16V low leakage electrolytics 1 220nF MKT polyester (code 224 or 220n or 0.22µF) Resistors (0.25W, 1%) 1 10MΩ (10%) 1 1MΩ 1 150kΩ 1 100kΩ 2 2.2kΩ 2 1MΩ horizontal trimpots (VR1, VR2) board while the edge that have the pillar cutouts is held within the integral side supports on the case. Place the PC board in the case with its edge pressed into the side supports and mark out the hole positions for the outer edge mounting holes. Drill out these holes in the base of the case and countersink them from the underside of the box suitable for countersunk screws. The side supports on the other side of the case need to be removed to provide space for the battery to mount between the box side and PC board. Full-size etching pattern for the fridge door-open alarm PC board. These are removed with a pair of pliers twisting them sideways until they break out. Alternatively side cutters could be used or a chisel. Use safety goggles when doing this as pieces can fly out as they break. Secure the 10mm tapped spacers to the base of the case with the countersunk screws. The PC board is secured to the top of the spacers using M3 pan head screws. Solder the battery leads to the supply PC stakes as shown on the overlay diagram. Place the lid onto the case and mark out the centre position of the piezo siren. The siren will have a label attached that says, “remove after washing”. This label can be removed now. The hole in the lid needs to be about 6mm in diameter to ensure the full sound intensity can be emitted from the siren. Testing The alarm is now ready to be tested. Adjust VR1 to centre position and VR2 fully anticlockwise. Connect up the battery. The alarm should sound after about 10 seconds giving short bursts of sound. If this does not happen, Make sure you are not working in the dark. Also check that the parts have been correctly placed on the PC board. Also measure the voltage at pin 2 of IC1. This should be close to 9V. Pin 4 of IC1b should be at 0V. Voltage between pin 7 and pin 14 of IC1 should be about 9V. Adjust VR2 for the desired timeout before the alarm sounds. Fully clockwise will provide a nominal 100 seconds before the alarm will sound. The alarm needs to be placed in complete darkness before the siren can be silenced. Simply placing a finger over the LDR is not sufficient. Note also that the alarm may take some 10 to 20 seconds to switch off in darkness as the LDR slowly increases its dark resistance. In a freezer, this time might increase to several minutes! You can test the alarm by placing it inside a drawer instead of the refrigerator. Adjust VR1 so that the alarm sounds if the drawer is opened slightly. Now place the alarm unit inside the fridge or freezer and check that it operates correctly after its temperature has stabilised. You will need to readjust VR1 if the alarm is placed inside the freezer. This is because the threshold voltages for IC1a change with temperature. Also the dark resistance of the LDR does not rise to the same value found at room temperatures. Variations If you want a longer delay time, increase the value of capacitor C1. A 220µF capacitor will double the delay time. If you want to increase the alarm burst rate, decrease C2 in value. The Refrigerator Alarm could also be used as a locker or drawer alarm. In this case, a shorter delay time may be better. Reducing C1 will reduce the time. Also an on and off switch could be placed in the supply to the battery SC to disable the alarm. Resistor Colour Codes o o o o o o siliconchip.com.au No.   1   1   1   2   3 Value 10MΩ (10%) 1MΩ 150kΩ 100kΩ 2.2kΩ 4-Band Code (1%) brown black blue silver brown black green brown brown green yellow brown brown black yellow brown red red red brown 5-Band Code (1%) brown black black green silver brown black black yellow brown brown green black orange brown brown black black orange brown red red black brown brown June 2004  63 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. Voice bandwidth filter This circuit passes frequencies in the 300Hz - 3.1kHz range, as present in human speech. The circuit consists of cascaded high-pass and low-pass filters, which together form a complete band-pass filter. One half of a TL072 dual op amp (IC1a) together with two capacitors and two resistors make up a secondorder Sallen-Key high-pass filter. With the values shown, the cut-off frequency (3dB point) is around 300Hz. As the op amp is powered from a single supply rail, two 10kΩ resistors and a 10µF decoupling capacitor are used to bias the input (pin 5) to one-half supply rail voltage. The output of IC1a is fed into the second half of the op amp (IC1b), also configured as a Sallen-Key filter. However, this time a low-pass function is performed, with a cut-off frequency of about 3.1kHz. The filter component values were chosen for Butterworth response characteristics, providing maximum pass-band flatness. Overall voltage gain in the pass-band is unity (0dB), with maximum input signal level before clipping being approximately 3.5V RMS. The 560Ω resistor at IC1b's output provides short-circuit protection. M. Sharp, Berala, NSW. ($35) El-cheapo fluoro ballast This simple circuit can start small (15W or less) fluorescent tubes such as those used in PC board exposure and EPROM ultraviolet erasure boxes. As you can see, the tube’s filament heaters are not used. Instead, ignition is provided by a voltage tripler formed by diodes D1-D3 and the two 6.8nF 2kV capacitors. At switch on, C1 charges up via R1 until the gas in the tube breaks down (around 700V). C1 then discharges through the tube, lowering the resistance enough to sustain continual AC current flow. C1 then continues to act as the ballast, with R1 included to prevent 64  Silicon Chip the three diodes shunting the tube on positive mains half-cycles. Adrian Kerwitz, via email. ($30) siliconchip.com.au Listing 1 Surveillance camera recorder This idea originated from the need to record video from a surveillance camera on a standard VCR, without wasting hours of tape. The circuit waits for a trigger signal before starting the VCR, which then runs for a predefined period. Virtually any mechanism could be used to trigger the circuit, including the output from a PIR (passive infrared) sensor, door switch, alarm panel, etc. The circuit is based on the popular Picaxe-08 microcontroller and is programmed to simulate the normal key presses used to set a VCR into record and stop modes. Control of the VCR is achieved by connecting the normally open contacts of two relays (RLY1 & RLY2) across the “record” and “stop” buttons. Some VCRs also need the “play” button to be pressed at the same time as the “record” button to start recording. In this case, a double-pole relay is needed for RLY1, as indicated on the circuit. The trigger input is interfaced via an optocoupler (OPTO1) to give complete isolation. This allows the entire circuit to be powered from an internal VCR supply rail, if available. Alternatively, it can be powered from an external 12-18V DC source. When the Picaxe (IC1) detects a trigger input, it switches on transistor Q1 to energise relay RLY1. The relay is held on for a second or so to simulate finger operation of the button(s). After the programmed time has elapsed (10 minutes), transistor Q2 is switched on to energise RLY2, stopping the VCR. The necessary Picaxe program is shown in Listing 1. It is easily modified for different times and applications. Important: do not attempt to modify your VCR unless you know exactly what you’re doing. Always use relays to connect to the record/play/stop switches, as these switches are “floating” in most VCR’s (ie. not connected to either the positive or ground rails). Also, keep switch lead lengths as short as possible. Darren Michell, Coraki, NSW. siliconchip.com.au 'picaxe 08 'PORT 0 = NOT CONNECTED 'PORT 1 = START RELAY OUTPUT 'PORT 2 = STOP RELAY OUTPUT 'PORT 3 = TRIGGER INPUT 'PORT 4 = LED OUTPUT Darren is this mMichell winner onth’s Peak At of the las L Meter CR pins=0 b3=0 MAIN: pause 300 if pin3=0 then start pulsout 4,500 goto main START: high 1 wait 2 low 1 TIMER: for b0 = 1 to 60 pause 950 pulsout 4,10000 next b0 let b3 = b3 + 1 if b3>=10 then stop goto timer STOP: high 2 wait 2 low 2 b3=0 goto main end ‘detect input goto start ‘flash LED1 (indicates running) 'start relay on 'delay seconds 'start relay off 'this sets VCR into record mode 'sets 60x1 sec =1min 'waits 1 sec 'flash working led 'loop until 60 reached 'count up 1 min 'goto stop sequence 'stop relay on 'delay seconds 'stop relay off 'resets time variable June 2004  65 Circuit Notebook – continued Experimental pendulum clock Using this design, you can construct an electromagnetically impulsed pendulum clock with a 1-second beat. On the prototype, the pendulum rod is 115cm long with a bob adjusted to make it beat every second. It is suspended on a short piece of mainspring from a watch, which is attached to a vertical backboard with a 6mm screw. The rod extends some 15cm below the bob and is fitted with large washes at the lower end. Note that for a pendulum to beat in seconds, there must be 99.4cm distance between the support and the centre of mass of the pendulum. Between the bob and the lower end is a 5mm wide white reflector facing back. Below the rod and 15mm to the left is the impulse solenoid, with a core but no actuator attached. The circuit comprises of four parts: (1) the sensor; (2) the counter and solenoid driver; (3) the clock driver; and (4) the clock. The sensor is built on its own small piece of strip board and is located on the centre line of the backboard behind the reflector. It utilises a Sharp IS471F infrared modulated detector (Farnell cat. 414- 2860) to eliminate interference from external light sources. The infrared emitter (IRLED1) must be mounted near to the detector (IRDET1) but be masked from it. The emitter radiates a coded signal toward the reflector. As the pendulum passes the centre line it reflects the signal back to the detector, which then gives a negative-going output pulse on pin 2. This makes the surface-mount LED (LED1) flash once. It also sends a signal to the counter and clock driver circuits on the main circuit board. Pulses from the sensor are fed into IC1, a 4020 14-stage ripple counter. The counter’s output (pin 6) goes high every 128 counts (seconds). These long duration pulses are inverted by transistor Q1 and differentiated by the 10nF capacitor and 22kΩ resistor, providing a narrow trigger pulse for a 7555 CMOS timer (IC2). The 7555 is wired as a monostable, driving the base of transistor Q3 with a relatively short pulse width suitable for energising the impulse solenoid. LED2 flashes in unison with solenoid pulses, and can be mounted right on the solenoid as a visual aid. Pushbutton switch S2 is used to provide gentle starting pulses to get the pendulum swinging smoothly at the outset. Switch S1 resets the coun- ter to zero. With this arrangement, the pendulum is set swinging and when it is to the left of centre, S1is pushed. Thus, the pendulum moves right to left on even numbered counts. At the 128th count, the solenoid gives a shot pull to the left just as the pendulum is passing through the centre line and moving right to left. The distance of the solenoid below the pendulum is adjusted so that it does not jerk the pendulum but adds a gentle nudge. The clock driver circuit also derives its timing from the output of the sensor. Negative-going pulses from the sensor are inverted by Q4 before being fed into a 4013 flipflop. On the output side, pins 12 & 13 go high in turn for one second. These pulses are too long to directly drive the clock coil, so they’re logically “anded” with the short pulses from the sensor using two gates of a 4093 NAND Schmitt trigger (IC4). The outputs from these gates then drive an adapted quartz clock movement. A suitable clock can be made from a standard quartz movement by isolating the coil and removing the battery. See SILICON CHIP, Dec. 1996, page 38 for full instructions or October 2001 page 37 for brief notes. This is an experimental clock so you may have to try various solenoids to find one that works for you. If necessary, the solenoid pulse duration can be changed by varying IC2’s timing components. If the Handy time delay with relay output This circuit is designed to provide delayed relay switching action at power on. The delay is a function of the time constant produced by the combination of R1 and C1. At power on, C1 charges slowly via R1 and the coil of the relay. When the voltage across C1 exceeds both the base-emitter voltage of Q1 and the gate trigger voltage of the SCR, gate current flows. This fires the SCR and switches on the relay. At power off, diode D1 rapidly discharges C1 through the 100Ω resistor, so ensuring that every time the circuit is restarted, as in a temporary outage, 66  Silicon Chip siliconchip.com.au suspension is too stiff, try impulsing at 64 beats from pin 4 of IC1, but note that the aim is to get the freest pendulum movement possible. The Synchronome and Hipp clocks were impulsed at 30-second intervals, so your clock could be even better. In the prototype, the reflector was the delay time is maintained. Just about any NPN transistor can be used for Q1, since after SCR1 fires, it is effectively out of the circuit. In fact, the only part that’s still active after SCR1 turns on is the relay. You can’t get much simpler than that! This circuit can be used to delay speaker turn-on, so avoiding the “thump” that occurs in some stereo systems at power on. A 5-second delay is enough for this application, requiring approximately 560kΩ for R1 and 10µF for C1. Another application might be as a motor protector in a short power outage. R. Besana, Henderson, New Zealand. ($30) siliconchip.com.au made from the back of an adhesive cable clip snapped on to the pendulum rod. The white back was masked to give a 5mm wide central vertical strip, giving clean, short pulses as the pendulum passes. Current drain is several milliamps, so the prototype was powered from an SLA battery fed from a float charger. A pendulum beating in seconds is called a Royal pendulum. Its length is the same as one in a typical long case (grandfather) clock. A. J. Lowe, Bardon, Queensland, ($45) CONTRIBUTE AND WIN! As you can see, we pay good money for each of the “Circuit Notebook” contributions published in SILICON CHIP. But now there’s an even better reason to send in your circuit idea: each month, the best contribution published will win a superb Peak Atlas LCR Meter valued at $195.00. So don’t keep that brilliant circuit secret any more: sketch it out, write a brief description and send it to SILICON CHIP and you could be a winner! You can either email your idea to silchip<at>siliconchip.com.au or post it to PO Box 139, Collaroy, NSW 2097. June 2004  67 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/ Universal circuit fits all vehicles: Courtesy light delay for cars Give your car that luxury feel by extending the time that your cabin lights remain on once the car doors have closed. For that extra touch of class, the lights fade to darkness at the end of the time period. By JOHN CLARKE A COURTESY LIGHT DELAY is a great feature for your car. It enables you to see to insert the ignition key and find your seatbelt when it is dark outside, without having to leave the door open. However, many cars lack this feature, particularly older models. When the car door is opened, the cabin lights do light up but as soon as the door is closed, the lights go out. This happens just when you are about to get settled into the seat. Of course you can fumble around and find the interior switch but wouldn’t it be nice if the lights stayed on automatically for a short time instead? And wouldn’t it be classy if the lights faded out at the end of the timing period instead of a sudden switch off? Another feature that would be useful is to have the courtesy light(s) automatically switch off whenever the parking lights are switched on. This would allow you to drive off if ready to go, before the courtesy lights had timed out. The final feature of this new design is its ease of installation. Past courtesy siliconchip.com.au light delay circuits have presented real problems for installation because of the various wiring combinations for courtesy lights in modern cars. In presenting this new design, we particularly wanted solve the connection problems presented by the popular “Electronics Australia” design from the April 1997 issue. This design needed to be built in one of four versions, meaning that it was a game of chance if the car’s wiring configuration was not known. By contrast, in our new design, the same circuit will work in all cases. Courtesy light circuits The automotive industry is renowned for its lack of standardisation when it comes to car wiring and this is certainly revealed when it comes to lighting circuits. Fig.1(a) and Fig.1(b) show how the courtesy lights can be wired. Some cars will have the lights connected to the +12V supply rail and the door switches connecting to the car chassis, while other cars will have the opposite connection, with the courtesy lights connecting to chassis and the door switches connecting to the +12V rail. Note that we have shown only two lights and two switches. Some cars will have more switches (one in each door plus a manual courtesy switch inside) and more lights. The switches are all wired in parallel and extra lights are also wired together in parallel. All of the courtesy lights switch on whenever one of the door switches is closed. This occurs when a door is opened. When all doors are closed, all the switches will be open and the courtesy lights will be off. Similarly, the two possible tail light connections are shown in Fig.1(c) and Fig.1(d). The tail lights are on when the lights switch is closed. This switch would also power the parking lights at the front of the car but this is not shown in this circuit. Main Features • • • • • • • Adjustable delay period from 7-40s Lights fade out at end of time period Courtesy lights switch off if parking lights switched on No standby current drain from battery when lights are off Universal circuit works with any 12V car system Low parts count Easy to install June 2004  71 Fig.1(a) Fig.1(b) Fig.1(c) Fig.1(d) Fig.1: the two possible wiring configurations for the courtesy lights are shown at Fig.1(a) and Fig.1(b), while Fig.1(c) and Fig.1(d) show the alternative tail light wiring configurations. For our Courtesy Light Delay circuit to work, we simply need to connect it across one of the door switches. We also need to connect it to the tail light wiring, so that the courtesy lights are immediately switched off if the tail lights are switched on during the timing period. In practice, this means that the Courtesy Light Delay requires just four connections to the car’s wiring. Two wiring leads connect across the door switch, while the other two connect directly across one of the tail light filaments. How it works Fig.2 shows the full circuit details of the Courtesy Light Delay. It comprises a Mosfet (Q1), an optocoupler (OPTO1), a diode (D1), a diode bridge (BR1) and a few capacitors and resistors. Q1 acts as a switch. It’s effectively wired in parallel with the door switches and switches power to the courtesy lights during the timing period, when all door switches are open. Fig.2: the circuit uses Mosfet Q1 to switch power to the courtesy lights when the car’s door is closed (ie, the door switch opens). Trimpot VR1 sets the time delay, while bridge rectifier BR1 monitors the tail lights and switches off Q1 via optoisolator OPTO1 if the tail lights are switched on. 72  Silicon Chip Note that the door switches are marked with plus and minus signs in Fig.1(a) and Fig.1(b). The positive rail of the delay circuit connects to the plus side of the door switch, while the negative rail connects to the minus side. In operation, the circuit derives its power from the vehicle’s 12V battery via the courtesy lamp filaments. As a result, the lamps act as low-value resistors in series with the supply. However, because the circuit draws so little current when it is operating, there’s very little voltage drop across the lamp filaments and so the circuit operates from almost the full battery voltage. Note that the current flows via the courtesy lamp filaments– it doesn’t matter whether the lamp filaments connect directly to the +12V supply as shown in Fig.1(a) or to ground as in Fig.1(b). The circuit operation is as follows. When a car door is opened, one of the door switches closes and the courtesy lights switch on as normal. During this time, the switch shorts out Mosfet Q1 and so there will be no voltage across the courtesy light delay circuit; ie, between its plus and minus terminals. As a result, capacitor C1 will be discharged via R1, while C3 will be discharged via resistors R3 and R4. Subsequently, when the door switch opens again (ie, the door is closed), the courtesy lights will go out and there will be close to 12V across the drain and source of Q1. This voltage also immediately appears across a series connected network consisting of capacitor C1, diode D1 and capacitor C2. Initially, C1 has a much lower impedance than C2, since it has 10 times greater capacitance – ie, 470µF vs 47µF. As a result, C2 is rapidly charged via C1 and so has almost the full supply voltage across it soon after power is applied to the circuit. In practice, if we ignore the voltage drop across diode D1, capacitor C1 will initially have about 1.1V across it and C2 will have 10.9V across it. What happens now is that C1 charges to the 12V supply via resistor R1. During charging, the voltage on the negative side of C1 gradually drops to the negative supply rail. At the same time, diode D1 prevents C2 from discharging since it is reverse biased. As a result, C2 remains with about 10.9V across it. At this point we need to understand siliconchip.com.au how Mosfet Q1 works. These devices have three terminals, called “gate”, “drain” and a “source”. When the gate voltage is at the same voltage as the source, the Mosfet is off and no current flows. However, when the gate voltage rises to its threshold of around 3-4V, the resistance between the drain and source suddenly goes low and so current can flow between these two terminals. In practice, the drain-source resistance depends on the gate voltage and is at its lowest (about 0.1Ω) when the gate voltage is more than 10V above the source. Now take a look at the circuitry involving capacitor C3, resistors R3 & R4 and the optocoupler (OPTO1). When power is first applied (ie, when the door is closed), C3 initially behaves like a short circuit (since it is discharged). As a result, current flows via R3 and switches on the transistor inside the optocoupler, thus clamping Q1’s gate at its the source voltage. At this point, C2 has about 10.9V across it (as already stated) but is prevented from quickly discharging since it is isolated from the optocoupler by resistor R2 (100kΩ). Capacitor C3 now quickly charges via resistors R3 & R4 and removes the base drive to the optocoupler’s transistor about 1ms after power is applied. However, this time period is so short that it does not allow C2 to discharge to any extent. Now that the optocoupler’s transistor is off, Q1’s gate voltage will be equal to the voltage that’s across C2. As a result, Q1 switches on to drive the courtesy lights. From this, it might appear that the courtesy lights will briefly switch off when the door is closed, before the circuit switches them back on again. In theory, this is true but the “offtime” is so short that it is virtually unnoticeable. So why do we use the optocoupler to briefly hold Q2’s gate low (ie, for Fig.3: install the parts on the PC board as shown here, taking care to ensure that the polarised parts are all oriented correctly. that 1ms period)? The answer is that without this feature, Q1 would switch on as soon as C2’s voltage reached the Mosfet’s conduction threshold of 3-4V. This would effectively “kill” the supply to the circuit and prevent C2 from charging any further. C2 would then quickly discharge via VR1 and the 220kΩ resistor to below Q1’s gate threshold and so the courtesy lights would go out again almost immediately. By contrast, by using the optocoupler to hold Q2’s gate low for 1ms, C2 charges to above 10.9V before Mosfet Q1 switches on. And that means that C2 must then discharge from 10.9V down to below 4V before Q1 switches off (and switches off the courtesy lights). The time it takes to do this gives us the delayed on period for the lights. VR1 allows this delay period to be adjusted by varying the discharge resistance for C2. At the end of the timing period, the lamp fades out as Q1’s resistance rapidly increases as its gate voltage falls below about 5V. This means that the voltage across Q1 gradually rises from about 0V when it is fully on to 12V when it is off. As a result, capacitors C1 & C3 slowly charge to the 12V supply, via R1 and R3 & R4 respectively. This slow rate of charge prevents C1 from recharging C2 and stops C3 from switching the optocoupler’s transistor on again. Tail light circuit As mentioned earlier, the circuit turns the courtesy lights off immediately if the parking lights (or the headlights) are turned on. This is achieved using bridge rectifier BR1 and the optocoupler. In practice, we don’t monitor the parking lights or the headlights directly. Instead, the circuit monitors the tail lights, since these are always on with both the parking lights and the headlights. As shown, the bridge rectifier is connected directly across the tail lights (ie, in parallel with one of the lamps). When the tail lights are on, there is 12V across them and this is applied to BR1, which then drives the LED inside the optocoupler via a 680Ω current-limiting resistor. This in turn switches on the transistor inside the optocoupler and so Q1 switches off and the courtesy lights go out. So the optocoupler performs a dual function: (1) it forms part of the initial 1ms delay circuit and (2) it plays a vital role in switching off the courtesy Table 1: Resistor Colour Codes o o o o o o o siliconchip.com.au No.   1   1   1   1   1   1 Value 220kΩ 100kΩ 22kΩ 10kΩ 680Ω 470Ω 4-Band Code (1%) red red yellow brown brown black yellow brown red red orange brown brown black orange brown blue grey brown brown yellow violet brown brown 5-Band Code (1%) red red black orange brown brown black black orange brown red red black red brown brown black black red brown blue grey black black brown yellow violet black black brown June 2004  73 they fit into the allocated holes. This device is fitted with a small U-shaped heatsink and the assembly is secured to the PC board with a screw and nut. The PC board is mounted inside the case by simply clipping it into the mounting clips. Before doing this, you will have to mark out and drill two holes in one end of the case, to allow for wire entry to the screw terminals. These holes are located 11mm down from the lip and 18mm in from the outside edge of the case and are made using a 6mm drill. Note: for 24V operation, change both C1 and C2 to 470µF 25V and change the 680Ω resistor to 1.2kΩ. Installation The completed PC board clips into the side pillars of a standard plastic case. Note the small heatsink fitted to Mosfet Q1, to keep it cool. lights when the tail lights are switched on. Note that the connections to the tails-lights can be made without any regard as to the polarity. That’s due to BR1, which ensures that the positive voltage rail is fed to the anode of the Parts List 1 PC board, code 05106041, 78 x 46mm 1 front panel label 1 plastic box, 82 x 54 x 31mm 1 mini heatsink, 19 x 19 x 10mm 2 2-way PC board mount screw terminals, 5.08mm spacing 1 M3 x 10mm screw & nut Semiconductors 1 MTP3055E 14A 60V Mosfet (Q1) 1 4N28 optocoupler (IC1) 1 W04 1.2A bridge rectifier (BR1) 1 1N914, 1N4148 diode (D1) Capacitors 1 470µF 16V PC electrolytic (C1) 1 47µF 16V PC electrolytic (C2) 1 100nF MKT polyester (C3) Resistors (0.25W 1%) 1 220kΩ 1 10kΩ 1 100kΩ 1 680Ω 1 22kΩ 1 470Ω Miscellaneous Automotive wire, connectors, mounting brackets, etc. 74  Silicon Chip optocoupler’s internal LED. The wiring arrangement of the tail light circuit is also unimportant since the circuit simply monitors the voltage across the lamps. Construction All the parts for the Courtesy Light Delay are mounted on a PC board coded 05106041 (78 x 46mm). This then clips into a standard plastic case measuring just 82 x 54 x 31mm. Fig.3 shows the assembly details. Begin by checking the PC board for any shorts between tracks or breaks in the copper. That done, remove the corners of the PC board if this hasn’t already been done, so that the board clears the four pillars inside the case. Now for the parts assembly. First, install the resistors in the positions shown, followed by diode D1 and the optocoupler (OPTO1). Table 1 shows the resistor colour codes but it’s also a good idea to check each one using a digital multimeter before installing it on the board. Take care when installing D1 and OPTO1 – they must be oriented as shown (see also Fig.1 for the device pinouts). Next, install trimpot VR1 (this may be coded 105), then install the three capacitors, bridge rectifier BR1 and the two 2-way terminals. Again, check to make sure that BR1 and the two electrolytic capacitors (C1 & C2) are oriented correctly. Finally, install Mosfet Q1 by bending its leads at right angles so that The Courtesy Light Delay can be mounted in any convenient location under the dashboard. It’s up to you how you secure it, since the circumstances will vary from vehicle to vehicle. To connect the unit, you will need to access one of the car door switches and the tail light connections. Note that some door switches will have two wires, while others will only have a single wire connection. In the latter case, one contact is connected directly to chassis at the switch mounting position. Note also that it’s important to get the door switch connections to the unit the right way around – ie, the positive door switch connection must go to the positive rail of the Courtesy Light delay. You can quickly determine which is the positive door switch connection by using your multimeter to measure the voltage across the door switch when it is pushed open. If there’s only a single wire running to the switch, this will be the positive (the chassis connection is negative). It’s a good idea to disconnect the vehicle’s battery before running the wiring, to prevent any inadvertent short circuits. Note that all wiring should be run using proper automotive cable and connectors. The “Tail lights” terminals on the Courtesy Light Delay are simply connected across one of the tail lights. You can access this wiring either directly at the tail lights or at the lights switch or the fusebox. Alternatively, you can connect these terminals across one of the parking lights at the front of the car. It doesn’t matter which way around you connect siliconchip.com.au Fig.4: here are full-size artworks for the PC board etching pattern and for the front panel. them, since the bridge rectifier automatically caters for both polarities (as explained previously). Once the wiring is complete, reconnect the battery and check that the courtesy lights remain on after the door is closed. Now turn the parking lights on – the courtesy lights should immediately go out again. You can now trigger the courtesy lights again and set the “lights-on” delay period using VR1. Turning VR1 clockwise will increase the delay period. Troubleshooting If the courtesy lights are always on, it may be because the door switch terminals have been connected with reverse polarity. If that happens, the courtesy lights turn on via the intrinsic reverse diode inside Q1. Simply swapping the leads to the door switch will fix this problem. If the lights do not remain on after the door is closed (and the connections are correct), check that there is no voltage applied to the “Tail light” terminals on the PC board. If there’s no voltage here, the problem will be on the PC board itself. The first step is to carefully check the copper side of the board for missed solder joints and solder bridges between adjacent tracks. That done, check that all components are oriented correctly and that they are in their correct positions. Finally, check that there is 12V between the drain and source terminals of Q1 when the door switches are open (ie, with the doors closed). If there is no voltage here, check your wiring back to the door SC switch. siliconchip.com.au June 2004  75 Check power consumption, costs, greenhouse gas emissions and more . . . How MUCH POWER are your appliances using? Despite international efforts to reduce the standby power requirements of appliances, this modern phenomenon continues to be a real problem. Virtually every mains-powered device is now in on the act, or soon will be. Standby power increases your energy bill and adds to the greenhouse effect. By PETER SMITH T V SETS, STEREOS, VCRs and the like have long relied on standby power. More recently, “convenience” electronics have been grafted into up-market household items such as dishwashers, coffee makers, cordless telephones and washing machines, all of which are designed to be permanently powered. Don’t think that these devices use much power when “off”? Well, you might be surprised to discover that 10-15% of all household power is consumed by devices in “standby” mode. According to a 2001 study by “Choice” magazine, appliances not performing their main task drew a constant total of 87W, on average. That works out to 760kWh in a year, for a cost of almost $100. And standby power consumption certainly hasn’t 76  Silicon Chip decreased since then. Consider the 100 million homes in the United States, for example. In total, they consume roughly 5GW of standby power. According to one source, this equates to about 8GW after distribution losses and generation reserves, or about the output of eight power plants. And that’s just for the domestic sector! With this in mind, you may wish to save some money and the environment by switching off appliances at the power point when not in use. Of course, it’s simply not practical to power off all devices. For example, microwave ovens and VCRs include a real-time clock that would need to be programmed at every power up, while cordless phones need to be on all the time. However, other devices such as PCs and their peripherals can be switched off. Measuring power usage Before you can make informed decisions about power usage, it’s necessary to know how much each device consumes, both during normal operation and in standby mode. Typically, the power rating printed on the label of a product indicates maximum input only, accounting for things like surge current at power up, motor start, etc. Real power usage is likely to be quite different. How you use an appliance will also have a major impact. For example, if you normally run your fridge in the middle of its temperature range, it will obviously consume less average power than on the cooler settings. The answer is to connect each device in turn to an electronic power meter. That way, you can determine the average power consumption, in line with actual usage. To help with this, a South Australian company, Computer Control Instrumentation, has come up with a great little handheld meter called the “Power-Mate”. It can measure instantaneous power use, accumulated energy consumption and more. Power-Mate, mate The Power-Mate is supplied in a 150 siliconchip.com.au Automating PC Power-Up Powering off your PC and associated peripherals from the mains will eliminate standby power usage and save you some money. It also reduces the PC’s exposure to mains-borne surges and may prolong power supply life. However, a recent email from one of our readers points out that when powered up from the mains, all late-model PCs simply enter standby, or “soft power” mode. You then need to push the front-panel power switch to boot up. Not content with having to perform this extra step, he went on to describe a simple means of “pushing” the button electronically, so that his PC powers up as soon as mains power is applied. On all late-model (ACPI-compliant) PCs, the power switch is connected to an I/O controller chip on the motherboard. This chip is powered from the 5V standby supply, so it’s always powered when mains power is present. Pressing the switch closes a circuit to ground, signalling the I/O controller to electronically switch power to all other circuits and thus boot up the machine. As shown in Fig.1, a large value capacitor can be connected across the switch to simulate a switch press. At power up, the capacitor charges slowly via a pull-up resistor internal to the I/O controller chip. If the capacitor is large enough, the I/O controller sees a valid logic low level on the switch input line after the power supply outputs have stabilised. We’ve also included a 100Ω resistor in series with the capacitor to limit discharge current into the I/O controller at power off. Several motherboards we’ve examined have a resistor in series with the ground line, which would achieve the same result. However, as we can’t be sure that they all do, it’s wise to include the resistor anyway. The capacitor and resistor can be soldered directly to the power switch pins. Insulate all leads with tubing as necessary to prevent short circuits. Note that the polarity of the capacitor is important. Use your meter to determine which of the two wires from the motherboard is the ground wire. The ground wire will measure between zero and about 500Ω to case ground, whereas the I/O controller input will measure much higher. The suggested value of 470µF for the capacitor should work in most cases. However, differences in power supply design may mean that you’ll need to increase this value for your particular PC. Silicon Chip Binders REAL VALUE AT $12.95 PLUS P & P H SILICON CHIP logo printed in gold-coloured lettering on spine & cover H Buy five and get them postage free! Price: $A12.95 plus $A5.50 p&p. Available only in Australia. Just fill in the handy order form in this issue; or fax (02) 9979 6503; or ring (02) 9979 5644 & quote your credit card number. Important: always disconnect AC power from your PC before opening the case! Note that old “XT” & “AT” type PCs do not consume standby power; the front-panel power switch physically switches mains power to the power supply input. KALEX • High Speed PCB Drills • PCB Guillotine Laser Labels • PCB Material – Negative or Positive Acting • Light Boxes – Single or Double Sided; Large or Small • Etching Tanks – Bubble • Electronic Components and Equipment for TAFEs, Colleges and Schools • Prompt Delivery We now stock Hawera Carbide Tool Bits Fig.1: a 470µF capacitor and a 100Ω resistor connected to the front-panel power switch are all you need to make your ATX computer boot as soon as mains power is applied. siliconchip.com.au 718 High Street Rd, Glen Waverley 3150 Ph (03) 9802 0788 FAX (03) 9802 0700 Website: www.users.bigpond.net.au/kalex Email: kalexpcb<at>bigpond.net.au ALL MAJOR CREDIT CARDS ACCEPTED June 2004  77 Special Offer Table 1: Power-Mate Specifications Measurement/Calculation Range Watts 0 - 2500W Volts 170- 270V RMS Amps 0.000 - 10.000A RMS Cost & cost per hour 0 - 99.9999 ($) Cost per quarter & year 0 - 9999.99 ($) Energy 0 - 999.999 kWh Greenhouse gas 0 - 999.999 kg Run time (max). 99 hrs, 59 mins, 59 secs Basic accuracy: better than 1% for all measurements x 80 x 30mm plastic case. It features a bright red 7-segment display and includes a four-button tactile keypad. A 1-metre cable exits from the case, terminated in a combination mains plug and “piggyback” style socket. Hooking up an appliance for testing couldn’t be easier. The Power-Mate plug goes into the mains outlet first and the appliance simply plugs in on top. Maaaate! In all, seven primary measurements and calculations can be displayed. Repeatedly pressing the “Mode” button cycles through each of the possibilities, as well as the “Setup” and “Clear” functions that we’ll come back to shortly. There are also 15 additional display functions, accessed by pressing one of the other three colour-coded keys, labelled “Enter”, “+” and “-”. It’s easy to determine what information is available in a particular mode by referring to the matching colour-coded table below the keypad. Measurements include line voltage (volts), current drain (amps) and the power consumed (watts), all in real time. A simple press of the “+” or “-” buttons momentarily displays the maximum or minimum readings taken since power on. These measurements would be handy for service technicians, who often need to measure things like start-up and surge currents. The real power of this unit (pun intended) is to be found in its energy consumption and cost calculation functions. At power up, the PowerMate immediately begins to show the accumulated energy used by the appliance in kWh units; this is the default display in “Energy” mode. You can also see the projected hourly energy usage based on measurements thus far by pressing the “Enter” button. Pressing the “-” and “+” buttons extrapolates the measurements over quarterly and yearly periods, respectively. Hit the “Mode” button again and you can immediately see how much it’s costing you to run the appliance. Once again, you can have the option of displaying current, hourly, quarter or yearly costs. It surely doesn’t get The Power-Mate is designed, manufactured and approved for use in Australia. It is available from the Alternative Technology Association, on the web at www. ata.org.au or phone (03) 9419 2440. Currently, the unit is priced at $346 plus GST in one-off quantities, which includes a 12-month warranty. Computer Control Instrumentation is making 25 units available to SILICON CHIP readers at the special price of $315 plus GST. To take advantage of this special offer, e-mail Mike Russ at mike<at> c-c-i.com.au or write to PO Box 195, Goodwood, SA 5034. Note that only bank cheques, money orders or bank transfers will be accepted for this offer. any easier than this! For the environmentally conscious, the unit also calculates the equivalent amount of greenhouse gas liberated, based on the ratio of energy consumed to a constant. By default, this is calculated at 1.2kg of CO2 per kWh, which is the accepted value for fossil-fuelled electricity generators. Both the cost of electricity per kWh units and the constant used for greenhouse gas calculations can be programmed in “Setup” mode. Entered values are retained in memory at power off. Finally, a “Clear” function allows you to reset the accumulated values of time, energy, cost and greenhouse gas emissions without having to turn SC the unit off. COMING NEXT MONTH How Many Watts? For those who prefer to build their own, watch out for our Energy Meter in next month’s issue. It features a multi-function digital readout that will tell you energy usage, actual power cost and much more for the various appliances in your home. It’s easy to build and is based on a PIC microcontroller. 78  Silicon Chip PROTOTYPE SHOWN siliconchip.com.au PRODUCT SHOWCASE Philips launches new LCD Monitor range Ranging from 15-inch to 30-inch, plus a 23-inch widescreen model, Philips new 2004 range of LCD monitors offers a wide choice of styles and performance as well as size. In the popular 15, 17 and 19-inch models, the range has been further sub-divided into S-line (standard), B-line (business) and P-line (professional) models. Professional models incorporate Philips’ “LightFrame” technology which enhances brightness, sharpness, contrast and colour. A viewing angle of up to 176° is available on some models and the contrast ratio is as high as 700:1. Prices of the new range, available this month, start at $749 for a 15-inch up to $3299 for the 20-inch. The widescreen 23-inch model has an RRP of $3999. The 30-inch display model is priced at $6999. A Kensington anti-theft lock is fitted to the widescreen model and is available as an option on the other LCDs. Resolution of the 17 and 19-inch models is 1280 x 1024 (SXGA); the widescreen model 1920 x 1200. All models feature high quality speakers integrated into the screen surround. Contact: Philips Electronics Locked Bag 30, North Ryde NSW 1670. Tel: (02) 9947 0000 Fax: (02) 9947 0474 Website: www.philips.com.au New LabVIEW 7.1 graphical development software extends Express technology National Instruments’ LabVIEW 7 has had a significant upgrade with the release of version 7.1, extending Express technology to automated instrumentation and real-time applications. Last year, LabVIEW 7 Express introduced a revolutionary way to create test, measurement and control applications with configuration-based development and code-generation tools. By extending Express technology to the broad spectrum of NI automated instrumentation, LabVIEW 7.1 simplifies development for all users, regardless of their hardware platforms (LabVIEW is available for Windows, Mac, Sun siliconchip.com.au Solaris and Linux operating systems). LabVIEW 7 continues to advance automated instrumentaion for hardware platforms ranging from high-performance modular instruments to real-time data acquisition systems and handheld devices. With five n32 Express VIs for NI Digitisers, signal generators and high-speed digital I/O, engineers can configure sophisticated measurements and acquire data with just a few mouse clicks. “Smart” AM-FM Monitor Receiver The SMR-01 “Smart” Monitor Receiver from Elan Audio is a professional broadcast device, designed to be installed in a remote location such as a provincial or country town having one or more unattended broadcast transmission services. It can be installed on a temporary basis to remotely listen to local AM or FM services, or installed permanently to monitor and report transmission fault conditions. Its primary purpose is to sequentially monitor up to eight broadcast services in the area where it is installed and report carrier, program audio and pilot tone failure. Ordinary fax is, for reliability reasons, the preferred method although the SMR-01 can be programmed to report to a mobile phone or a TAM where the calling number will be registered on the Caller ID facility as a missed call. Contact: Elan Audio 2 Steel Ct, Sth Guildford WA 6055 Tel: (08) 9277 3500 Fax: (08) 9478 2266 Website: www.elan.com.au STEPDOWN TRANSFORMERS 60VA to 3KVA encased toroids Contact: National Instruments (Australia) PO Box 382, North Ryde NSW 2113 Tel: 1800 300 800 Fax: (02) 8572 5290 Website: www.ni.com Harbuch Electronics Pty Ltd 9/40 Leighton Pl. HORNSBY 2077 Ph (02) 9476-5854 Fx (02) 9476-3231 June 2004  79 A Quick Visit to CeBIT Australia 2004 There are five CeBIT shows held around the world: Sydney’s turn was in early May, with the largestever Australian show occupying three halls at Darling Harbour Exhibition Centre. We made a flying visit to the show as this issue went to press to see what the latest and greatest was in ICT. “More of the same but different” is one phrase which springs to mind. It’s not hard to get “boggled” by all that’s on offer. And at the big shows, it’s not hard to get lost! Several companies were claiming “world’s firsts” or “technology breakthroughs” – D-Link was one I recall offering several new speed breakthrough products, especially in wireless technology. D-Link weren’t the only ones with wireless – it was of course everywhere – whatever you wanted in wireless, at every level, was available. We had the opportunity to talk to several wireless suppliers and hope to look at some of the more unusual (or newest) wireless products in the coming months. Broadband applications were also a big feature, both in hardware and software. And combining the two, wireless broadband was a very popular topic. SMS tools were also in abundance. Very little product selling was occuring off the stands; one company which was had people queued five and six deep to buy USB equipment that was keenly, but not bargain, priced. One thing that did catch our attention was the number of exhibitors offering ways to silence noisy computers. You would think CPU manufacturers would look after this important area themselves but on speaking to several people, we found the problem is much more widespread than we imagined (and I thought it was just my computer that was noisy!). Again, we plan to do something with this in a future issue of SILICON CHIP There was a plethora of applications software covering the whole gamut. Very interesting if you’re in the market for that particular 80  Silicon Chip application, otherwise not quite so noteworthy. One product which did catch my eye, having been involved in clubs and volunteer organisations most of my life, was the ClubsInc Governance and Risk Management program, designed to take the guesswork out of running a not-for-profit organisation. (www.clubsinc.com). It was good to catch up with our old friends, Microgram, who had a whole stand of new and innovative products. Manager Ian Watts has promised to let readers see some of those goodies in the near future. I just had to include the photo below, taken on one exhibitor’s stand, simply because it was so “out there” – a 2.0GHz Pentium running at 3.45GHz, with water cooling to keep it under control. And don’t forget the tricked-up, lit-up case. There was more pipeware in this PC than at Bob’s Plumbing Store! I resisted the temptation to deposit my business card in the ubiquitous goldfish bowl on just about every stand, though each offered me the chance to win a prize (and some were quite significant/valuable). My email is spammed enough already, thank you very much! Solar 12V trickle charger Even brand new lead acid cells can discharge to a point of permanent damage or decreased life span if not regularly charged. Altronics are now stockists of a handy solar trickle charger which can keep a 12V lead acid battery powered up even when it’s not used for months at a time! The portable solar charger provides a constant charge for free, provided by the sun! It’s an absolute must for yachts, RVs/ caravans, boats, cars, etc. It can plug into a cigarette lighter socket or clips directly to your battery. Contact: Altronics PO Box 8350, Perth Business Centre 6849 Tel: 1300 797 007 Fax: (08) 9428 2187 Website: www.altronics.com.au New edition of popular satellite TV guide The Practical Guide to Satellite TV is now in its fourth edition, with over 2000 copies sold. It’s a mine of information for anyone interested in this fascinating subject which, as author Garry Cratt says, didn’t exist until the late 20th century! His company, Av-Comm, is one of the leaders in the field of professional satellite TV – now that information is available to the layman in one easy-to-read 156-page manual which explains everything from history to what you need for satellite TV. Priced at $49 inc GST, it’s available at many bookstores and electronics stores or direct from Av-Comm. Contact: Av-Comm PO Box 525, Brookvale NSW 2100 Tel: (02) 9939 4377 Fax: (02) 9939 4376 Website: www.avcomm.com.au siliconchip.com.au SILICON CHIP WebLINK How many times have you wanted to access a company’s website but cannot remember their site name? Here's an exciting new concept from SILICON CHIP: you can access any of these organisations instantly by going to the SILICON CHIP website (www.siliconchip.com.au), clicking on WebLINK and then on the website graphic of the company you’re looking for. It’s that simple. No longer do you have to wade through search engines or look through pages of indexes – just point’n’click and the site you want will open! Your company or business can be a part of SILICON CHIP’s WebLINK . For one low rate you receive a printed entry each month on the SILICON CHIP WebLINK page with your home page graphic, company name, phone, fax and site details plus up to 50 words of description– and this is repeated on the WebLINK page on the SILICON CHIP website with the link of your choice active. Get those extra hits on your site from the right people in the electronics industry – the people who make decisions to buy your products. Call SILICON CHIP today on (02) 9979 5644 A 100% Australian owned company supplying frequency control products to the highest international standards: filters, DIL’s, voltage, temperature compensated and oven controlled oscillators, monolithic and discrete filters and ceramic filters and resonators. Hy-Q International Pty Ltd Tel:(03) 9562-8222 Fax: (03) 9562 9009 WebLINK: www.hy-q.com.au We specialise in providing a range of Low Power Radio solutions for OEM’s to incorporate in their wireless technology based products. The innovative range includes products from MK Consultants, the world-renowned specialist manufacturer. Our website is updated daily, with over 5,500 products available through our secure online ordering facility. Features include semiconductor data sheets, media releases, software downloads, and much more. TeleLink Communications JAYCAR JAYCAR ELECTRONICS ELECTRONICS WebLINK: telelink.com.au WebLINK: www.jaycar.com.au WebLINK: www.jaycar.com.au Tel:(07) 4934 0413 Fax: (07) 4934 0311 Tel: Tel: 1800 1800 022 022 888 888 . For everything in radio control for aircraft, model boats and planes, etc. We also carry an extensive range of model flight control modules including GPS, altitude and speed, interfaces, autopilot and groundstation controllers. More info on our website! Silvertone Silvertone Electronics Electronics Tel:(07) 4639 1100 Tel/Fax: (02)Fax: 9533(07)4639 3517 1275 WebLINK: www.silvertone.com.au WebLINK: silvertone.com.au SILICON CHIP available at WIA VK2 Bookshop Along with an extensive range of technical books, from this month, SILICON CHIP will be available from the VK2 Divn. Wireless Institute of Australia Bookshop at 109 Wigram St, Parramatta, NSW; Tel (02) 9689 2417; fax (02) 9633 1525. More information is available from www. wiansw.org.au/bookshop siliconchip.com.au JED designs and manufactures a range of single board computers (based on Wilke Tiger and Atmel AVR), as well as LCD displays and analog and digital I/O for PCs and controllers. JED also makes a PC PROM programmer and RS232/RS485 converters. Jed Microprocessors Pty Ltd Tel: (03) 9762 3588 Fax: (03) 9762 5499 WebLINK: jedmicro.com.au We endeavour to provide a range of technical books of interest to the Radio Amateur as well as electronics enthusiasts, at competitive prices. Special discounts are offered to WIA members. We are the only bookshop of this type in Australia. Wireless Institute of Australia (VK2) Tel:(02) 9689 2417 Fax: (02) 9633 1525 WebLINK: wiansw.org.au/bookshop/ · Hifi upgrades & modification products - jitter reduction and output stage improvement. · Danish high-end hifi kits - including pre- amps, phono, power amps & accessories. · Speaker drivers including Danish Flex Units plus a range of accessories. · GPS, GSM, AM/FM indiv. & comb. aerials. Group Soundlabs Group Syd: (02) 9660-1228 4627-8766 Melb: Melb: (03) (03)9859-0388 9859-0388 Syd: (02) WebLINK: WebLINK: soundlabsgroup.com.au soundlabsgroup.com.au Stunning new Mordaunt-Short Avants The new UK-designed Avant 900 from Mordaunt-Short has completely new drive mechanisms, redesigned cone to surrount joins, new radially asymmetric drive point, new vented structed steel chassis . . . and are housed in completely new honey-maple finish cabinets. Prices range from $499 pair for bookshelf monitors to $1599 each for Contact: the Avant 909W powered subwoofer. QualiFi For more information, distributors, etc Tel: 1800 24 24 26 Website: www.qualifi.com.au visit the QualiFi website. June 2004  81 Upgraded software for the Windows-based Eprom Programmer The Windows-based EPROM Programmer design published in the November 2002 February 2003 issues has been very popular but since then a small number of bugs have been discovered in the software. These have been fixed and the upgraded software is available on our website. By JIM ROWE W HEN I PRESENTED the software for the EPROM Programmer back in the February 2003 issue of SILICON CHIP, I had spent quite a bit of time writing and debugging it. So when we published it, we thought it was pretty free of bugs. Well, it’s probably not surprising that once people began to use the software, the first version turned out to have a few minor bugs. I discovered one myself, when I went to program a bunch of 512KB EPROMs recently. So there was nothing for it but to fire up Visual Basic 6.0, track those bugs down and fix ’em. While I was at it, I also took the opportunity to make a few small improvements to the program. So we have now been able to put an updated and revised Version 1.3 of the software on the SILICON CHIP website, ready to be downloaded and installed by anyone who has built the EPROM Programmer. You’ll find it in a single 1.7MB zippedup file called EPROMProgV13.zip but if you’d like to look at a copy of the VB6 source code, this is also available as a 82  Silicon Chip PDF file (EPROMProgV13.pdf). What’s changed Probably the most irritating bug in the first version was one in the EPROM verify routine. It was a missing variable type conversion in the statement which works out the original address of a data byte read back from the EPROM in the program’s storage array, so it can compare the two. Because one of the array address variables was in integer form, the statement produced an overflow error as soon as the verify routine reached the first EPROM address beyond 32,767. So the bug didn’t show up if you were programming and verifying EPROMs of 256Kb (32KB) or smaller, but the program would crash with an “Overflow Error 6” when you tried to verify larger EPROMs. The annoying thing is that this same overflow error had originally shown up in the program’s main EPROM reading and programming routines, for the same reason, and I had fixed them by adding a variable type conversion (integer to long) in the appropriate statements. I thought I had fixed the verify routine at the same time but apparently not. The type conversion is definitely in that routine now, so you can now verify the larger EPROMs without an overflow problem. By the way, you could still read and program larger EPROMs with the first version; the error occurred only during verifying. The other main bug was that the program would often get “confused” about where its configuration file had been stored by the last session and would not be able to find the config file when it started up – forcing you to feed in things like the Programmer’s port address all over again. This turned out to be due to not specifying the full path for the config file in the program’s config file save and load routines – just the file’s name. So in version 1.3, the full path is specified in both routines, to ensure that the program always saves the config file where it can find it again next time. Improvements As well as fixing these bugs, an “About” item has been added to the main menu of the program. This allows you to easily check at any time which version of the software you’re running. When you click on this menu item, the program displays a small dialog box with the version details and so on. A couple of small changes have also been made to the main programming routine, so if you’ve indicated at the start of programming that you want it to verify after programming, it doesn’t siliconchip.com.au Fig.1: the latest version of the EPROM Programmer software includes an “About” item, which allows you to check which version you have running. give you a “Programming Completed” dialog at the end of programming – it just proceeds automatically with verifying. This is a little more convenient than with the first version, where you had to click the “OK” button in the dialog each time before it started to verify. It also speeds up the combined operation. Still one problem So the new version 1.3 fixes the known bugs in the EPROM programming software and is also easier to use. But note that there’s still one problem remaining: with some newer PCs, it seems to be almost impossible to get the software to communicate correctly with the EPROM Programmer hardware. In the February 2003 article, we mentioned that with some of the newer PCs fitted with “integrated” on-board EPP or ECP printer ports, you would very likely have to experiment with different port configurations in the machine’s BIOS before you’d get correct operation. This was based on my experience, where I had great trouble getting correct software-hardware communication on some machines until I tried changing the printer port’s BIOS configuration. However, even this doesn’t seem siliconchip.com.au to solve the problem with some machines. In fact, some of them seem to be extremely unwilling to allow any direct communication between the EPROM Programmer software and hardware – so you can’t even get the software to light the hardware’s LED3 in the Test dialog. I still haven’t been able to find out whether this is due to Windows simply not allowing direct communication with the printer port or if there’s some other cause like an extra “security feature” in the BIOS or chipset firmware of these machines. So at present, all I can suggest is that to use the programmer with these machines, you might have to add an extra printer port via a PCI card and use this instead of the integrated port. Hopefully, an add-on port won’t be quite so firmly in the iron grip of the BIOS and Windows and will allow the programmer software and hardware to talk to each other more readily. But if this still doesn’t happen, you might have to use the programmer with a different PC. It’s possible that the final solution will be to come up with new hardware for the programmer, using a USB interface instead of the printer port. That is a project which will have to wait for SC another time. Want really bright LEDs? We have the best value, brightest LEDs available in Australia! Check these out: Luxeon 1 and 5 watt LEDs All colours available, with or without attached optics, as low as $10 each Lumileds Superflux LEDs These are 7.6mm square and can be driven at up to 50mA continuously. •Red and amber: $2 each •Blue, green and cyan: $3 each Asian Superflux LEDs Same size and current as the Lumileds units, almost the same light output, but a fraction of the price. •Red and amber: Just 50 cents each! •Blue, green, aqua and white: $1 each. Go to www.ata.org.au and check out our webshop or call us on (03)9388 9311. June 2004  83 Vintage Radio By RODNEY CHAMPNESS, VK3UG S Restoration tips & techniques It’s not surprising that many vintage radio enthusiasts don’t come from an electronics background. In fact, prior to taking up the hobby, most never got closer to the subject than using the external controls on various pieces of electronic equipment. 84  Silicon Chip OONER OR LATER, a vintage radio enthusiast must decide which technical areas to become competent in so that they can at least carry out some restoration work. Some will simply do the cabinet work and clean the chassis but leave the electronics restoration to someone else. By contrast, others will want to do the lot. The problem is, electronic circuitry is a complete mystery to many newcomers. So how can a novice learn how to check and restore electronic circuits? Well, we all have to start somewhere and that’s the aim of this article – to provide a basic introduction. Of course, it won’t take you from knowing nothing about electronics to being an electronics wizard but at least it will be a start. Reading a circuit diagram As an example, the Kriesler 11-90 AC mantel receiver is used as the “guinea pig” for this article, as it has a relatively simple circuit. It is a broadcast-band receiver with four valves, one of which (the 6GV8) is a dual valve – ie, it has a triode and a pentode in the one glass “envelope”. As a result, the Kriesler 11-90 is functionally equivalent to a conventional 5-valve receiver. The circuit diagram is shown in Fig.1. As can be seen, it is well labelled, which makes checking things within the circuit relatively easy. A schematic circuit diagram is a “shorthand” method of showing how the parts are connected in a piece of equipment. For this reason, it’s essential that you become familiar with what the various symbols mean, in order to understand how the circuit works (if only at a basic level). siliconchip.com.au Fig.1: the circuit diagram for the Kriesler 11-90 AC mantel receiver. It uses four valves and covers the broadcast band. Let’s start with valves. These are usually drawn with a heavy oval shape which contains the various elements. We will use the 6N8 as an example – see Fig.1. Pin 3 is attached to the “cathode” of the valve and this element emits electrons when it is heated. Pin 2 is the control grid and is shown as a dashed line – it’s simply a grid of wires. The electrons from the cathode pass through the grid and are attracted towards the positively-charged “plate” which is attached to pin 6. Pin 1 is the “screen” grid (it screens the grid from the plate), while pin 9 is the “suppressor” grid. The latter “captures” electrons which bounce off the plate and takes them to earth (chassis). Pins 7 & 8 are the cathodes of the two detector diodes, which are located close to the main cathode at pin 3. Note that the heater connections for the valves are not shown in Fig.1. In practice, these are connected between pins 4 and 5 for most 9-pin miniature valves (it is assumed in most diagrams that you know this). So basically, the shorthand drawing of the valve is relatively close to what the internals of the valve are really like. Of course, the description here is a simplistic version of what really happens inside a valve. Identifying valve pins How do you identify which pin is which? Simple, the valve socket as viewed from below has a wider gap between two of its pins. This is the reference point and the pin numbers start from the left as number 1 and progress clockwise to number 9. Other valve sockets are similar in concept. For example, small 7-pin sockets are read in the same way, while octal sockets are read clockwise from the keyway pin on the spigot. The valve base diagrams usually make this clear. Other older valve socket types have different layouts. Checking through a valve data book will assist in identifying which pin numbers relate to which pins on their bases. Resistors & capacitors Resistors are the items with the “zig-zag” lines. For example, R10 is a 1MΩ (one megohm) resistor. The zigzag symbol always reminds me of a tortuous path which restricts current siliconchip.com.au flow and in some ways, resistors can be thought of as doing just that. Capacitors, on the other hand, are represented by two parallel lines – eg, C8. The lines can be thought of as being equivalent to the two parallel plates that make up the capacitor. However, this really is symbolic as June 2004  85 up quite well unless it has really been abused in some way or another. Cleaning the set not only improves its appearance but makes it much easier and more pleasant to work on. Fig.1: the Kriesler 11-90 was housed in a plastic cabinet and featured a simple handspan dial. Static tests they may have many parallel plates, with insulation (dielectric) of various sorts between each plate. For example, C3A and C3B are the tuning capacitor sections and they definitely have parallel plates that you can see. The symbol for C3A and C3B means that one series of plates moves while the others remain stationary (this is done to vary the tuning capacitance, so that the set can be tuned to different stations). Similarly, C4 is an adjustable (or variable) capacitor which is used during the alignment of the local oscillator (ie, when the set was manufactured). C12 and C13 are electrolytic capacitors and are different again. They have fixed values (40µF & 20µF respectively) and are also polarised – ie, the positive terminal of each capacitor must go to the positive supply rail (or more precisely, to a voltage rail that’s more positive than that for the negative terminal). Inductors & transformers Inductors and transformers such as L1 appear to look like coils, which of course they are. The three parallel series of dashed lines indicate that it is wound on a ferrite or iron dust core (a ferrite loopstick in this case). Similarly, intermediate frequency transformers IFT1 and IFT2 have adjustable ferrite cores, again used during the alignment of the set. 86  Silicon Chip Note that in both cases, the IFT windings are coupled together in close proximity. Audio and power transformers have the same coil-like symbol but they differ by having two (sometimes three) solid lines alongside each winding. This indicates that they have an iron core. Consider the power transformer (T1), for example. This is a 240V transformer with a primary winding (on the lefthand side of the lines) and two secondary windings (on the righthand side). These secondary windings provide nominal output voltages of 115V AC (for the high-tension or HT supply) and 6.3V AC (for the valve heaters). Note that many parts of the circuit are connected to earth (also called “common” or “chassis”). The most common symbol for this is the one used on the end of the line from pin 3 of all the valves except for the 6V4. This symbol consist of three parallel lines of progressively diminishing length. In this set, all points with this symbol are directly connected to the chassis. Starting restoration The first step in any restoration job is to give the set a thorough clean-up. This involves not only cleaning the cabinet but the chassis and the valves as well. In most cases, the set will come As stated before in this column, I never (or rarely ever) turn a set on before carrying out a number of static tests. It’s not nice having to repair a set that sends up smoke signals as soon as it is turned on. In fact, it really pays to be over-cautious here, to circumvent disasters before they happen. A digital multimeter is all you require for these initial tests, although an analog multimeter is also quite OK provided it has a rating of at least 20kΩ/V (20,000 ohms per volt). In fact, most common receiver faults can be found using just a multimeter. Make sure that the set is disconnected from the power point before starting the test procedure! The first thing to do is to carefully inspect the chassis, the components and all the interconnecting wires. Look for shorts and broken wires, particularly if someone has been there before you. It’s also a good idea to test the soldered joints by moving the wires attached to them where possible, as some may be what are called “dry joints”. These are soldered joints where the solder no longer properly adheres to the leads and/or terminals it is joining. If you do find any bad solder joints, the wires (or terminals) should be cleaned, re-tinned with solder and resoldered together. Next, make sure there are no shorting plates in the tuning capacitors. Shorts can be detected by first disconnecting the leads to the fixed plates. That done, you then connect a multimeter between the fixed and moveable plates and vary the tuning capacitor across its full range. There should be almost infinite resistance between the moving and fixed plates. If the plates are shorting, it should be possible to bend the moveable plates slightly to eliminate the problem. This can be a delicate job but it’s usually not too difficult provided the tuning gang hasn’t been seriously damaged. The next test is to make sure that the power transformer (marked T1 on Fig.1) has no short or partial short from the mains active and neutral wires (ie, the primary side) to chassiliconchip.com.au This under-chassis view shows that all parts are readily accessible. Note that using a knot to restrain the power cord is no longer legal. sis. An ohmmeter on its highest range should not show a reading of less than 10MΩ between points A and B on Fig.1. Most transformers test quite OK but it’s imperative to find the fault (or replace a faulty transformer) if a short is found. A much better test for the power transformer is to use a 1000V highvoltage tester across points A and B. If the high-voltage test is successful, with no apparent leakage, then the transformer is OK (at least as far as leakage to chassis is concerned). If the set only has a 2-wire power lead (and has a transformer), consider fitting a 3-core lead to earth the chassis, as this is a safer option. Of course, this work must only be carried out be someone who knows exactly what they are doing – a mistake here could prove deadly. Make sure too that the new cord is properly anchored – tying a knot in the cord to restrain it (as was commonly done many years ago) is no longer legal! Warning: if you are a novice, stay well away from hot-chassis (trans­ formerless) sets, which have one side of the mains directly wired to chassis. They really are potential death traps for the unwary. If in doubt, ask someone who’s qualified to give advice. Next, check resistor R12 to make sure it is about 120Ω. It should be replaced if it has drifted in value but note that an allowance of ±20% in any resistor or capacitor value is generally siliconchip.com.au OK. However, this doesn’t include electrolytic capacitors, which can have very wide tolerances; eg, +100% and -50% for the very old types. Similarly, check resistor R11 by measuring the resistance between points HT1 and HT2 on Fig.1 – you should get a reading of 3.3kΩ. If it is high, the resistor has drifted high in value and should be replaced if it is beyond the accepted tolerance range. Conversely, if it is low, it’s possible that either or both C12 and C13 are leaky and need replacing. However, before doing this, you could try “reforming” the two capacitors, as described later. The next step is to check the resistance between the HT2 and BIAS points. Initially, the meter should read up the scale then gradually increase in value to in excess of 50kΩ. Also, check the resistance between HT1 and chassis. You should get a similar value to the previous measurement. If either of these reads low – ie, below 50kΩ – it indicates that there is a partial short on the high-tension line. Either C12 and/or C13 could be leaky or there could be a problem elsewhere. This can be diagnosed as follows. First, removing all the valves will quickly indicate whether one or more of them has a problem. Valves rarely develop shorts, although some rectifiers do; eg, the 6X5GT. Next, measure all the resistors with an ohmmeter and if all is well, they will all be within 10% of their marked value. The only exception is R2, which shunts a low resistance winding in IFT1 – it will have to be checked with one lead disconnected from circuit. Similarly, disconnect one lead of each electrolytic capacitor (C12 & C13) and check them using an ohmmeter. Replace them if you get readings of less than 50kΩ. Now measure between pin 6 of the 6GV8 and the chassis and if this shows a short circuit, it is likely that C11 has short-circuited. You should also check capacitors C6 & C7, which are on the HT line near IFT1. If there is no indication of a short but the HT line measures just a few ohms to earth (chassis), then it is necessary to disconnect sections of the circuit until the shorting part is found. Output transformer The audio output (or speaker) transformer is a component that often gives trouble, as the primary winding has a habit of going open-circuit. To check it, measure between HT2 and pin 6 of the 6GV8 – you should get a reading of about 150-200Ω. However, depending on the impedance of the transformer, the resistance can be around 500Ω in some sets. A further quick check of the output transformer can be done using an analog meter. Select a low ohms range and connect the leads between HT2 and pin 6 of the 6GV8 – a click should be heard in the speaker. This indicates that all is probably well with the transformer and loudspeaker. Note: digital June 2004  87 capacitors are all located in parts of the circuit where leakage cannot be tolerated. Capacitors C6, C7 & C11 can be mildly leaky without this being a trouble in the set. However, C11 occasionally shorts in this position and it is a good idea to replace it anyway. If any capacitor gets warm after the set has been running for a few minutes (switch the set off and pull the power plug from the wall socket before testing), it is too leaky and should be replaced. somewhere near 140-150V, as there’s no load on the power supply. Now turn the set off and monitor the voltage at pin 3. It should decrease slowly, unless the electrolytics require “reforming”. To do this, turn the set on, let the rectifier (6V4) warm up, wait a few seconds until the voltage on pin 3 appears to have stabilised, then turn the set off again and let the capacitors discharge. Repeat this several times with a gap of a minute or so between cycles, until the capacitors discharge quite slowly. If the rectifier plates glow red during this procedure, then either the electrolytics are faulty or some other component is breaking down when the voltage is applied. In that case, the set should immediately be turned off. Disconnecting various sections of the set will then help to isolate the defective component. If the HT voltage still “disappears” within 10-15 seconds, it means that one or both capacitors have excess leakage and cannot be “reformed”. By disconnecting one capacitor at a time from the rectifier output, it is possible to determine which capacitor is faulty (ie, the faulty unit will discharge quickly compared to the good one when the power is removed). Note, however, that most modern electrolytic capacitors require little if any “reforming”. Dynamic tests Installing all the valves OK, now for the smoke test! First, remove all the valves, then plug the set into the wall socket and turn it on. The dial lamp is still in circuit so it should light up unless it has blown. Try a new one in its place if it has failed. Now keep an eye on the set while you run it for about 30 minutes. After this time, the power transformer should only be slightly warmer than the chassis. If it gets hot, then you have a faulty transformer. Fortunately, this is rare. If the transformer appears to be OK, the voltages on the two secondary windings can be measured. These will be about 10% higher than the voltages measured when the set is fully operating. Take care when measuring the high-voltage secondary – it’s capable of delivering a fatal shock! The next step is to install the 6V4 rectifier but switch the set off first. Now turn the set on again – the voltage on pin 3 of the 6V4 will probably rise to Once the power supply is working correctly, it is time to fit the rest of the valves. That done, turn the radio on, tune it off-station and measure the voltages at all the various points shown on the circuit. If everything is working correctly, these should all be within about 20% of the indicated values. Note that all voltages are measured with respect to earth, so it’s a good idea to use a clip lead to attach the earth lead of the multimeter to the chassis. If the voltage at HT 2 is much lower than 110V and the BIAS voltage is also low, it indicates that the 6V4 is low in emission and should be replaced. Conversely, if the HT 2 voltage is appreciably higher than 110V and the BIAS is noticeably less than -5V, this may indicate that the pentode section of the 6GV8 has lost emission and should be replaced. The voltage on pin 1 of the 6GV8 should be around 30V when checked It’s a good idea to thoroughly clean the chassis before checking the parts and starting restoration. Be sure to make a note of the valve positions before removing them from their sockets. multimeters usually don’t have much current flowing through their test leads, so a click may not be heard. All of the wound components (coils and transformers) should have continuity with reasonably low resistance. For example, the aerial, oscillator and IF transformers should not have more than a maximum of 100Ω across any winding and quite often are less than 10Ω. Paper capacitors Now let’s look at those components that often give trouble but are not easily detected using a multimeter. First, Ducon and UCC paper capacitors (from the 1960s) became renowned for problems. The Ducons became leaky and the UCCs often became intermittent and sometimes leaky. By “leaky”, I mean that they had relatively low resistance across them compared to a good capacitor – eg, a few megohms for a faulty one compared to 200-1000MΩ or more for a good one. Unfortunately, a “normal” multimeter will not normally detect this leakage, as it usually does not become apparent until a considerable voltage is applied across the capacitor in question. Note that some leakage can be tolerated in some capacitors but C2, C9 & C10 should all be replaced with modern polyester or similar capacitors of the same ratings. In fact, this should be done without question, unless you have a high-voltage tester. These 88  Silicon Chip siliconchip.com.au with a digital multimeter. If it is lower and resistor R8 is the correct value, the valve may be drawing too much current. If it is higher, the valve may be low in emission. Once again, try replacing the valve. By the way, the circuit indicates that this voltage is measured with a 1000Ω/V analog meter. However, this is probably a mistake as 20kΩ/V analog meters were common in 1962. On my set, I measured 22V with a 1000Ω/V meter and 26V with a digital multimeter. Resistor R8 is within tolerance and as both readings are below the indicated voltage, it would appear that the valve in my receiver is drawing more current than others of the same type. However, the receiver’s performance is quite satisfactory so replacement of the 6GV8 is not warranted. Both the 6AN7 and the 6N8 should have plate voltages of about 80V, while the screen grids should be at approximately 45V when the set is tuned “off-station”. What if it doesn’t work? By now, it is quite likely that the receiver is showing signs of life and you may even be able to tune stations in. In fact, at this stage it’s not unusual to find that the receiver is performing quite well. But what if it isn’t? Here are a few tests that can be conducted now that normal voltages are appearing around the circuit. First, turn the volume control fully up and put your finger on the top terminal of the volume control (but DO NOT do this with a live-chassis set). Be careful here, as the back of the volume control in this set carries terminals which are connected to the 240V AC mains (the pot functions as a combined volume control/on-off switch). If the audio output stage (based on the 6GV8) is functioning correctly, a healthy “blurt” will be heard from the loudspeaker. If not, you’ve got a problem in the audio stages. If you’ve carried out all the tests suggested previously, then it is likely that the valve is defective and another should be tried in its place. If there are still no stations to be heard after getting the audio section working, the next thing to check is the local oscillator. This can be done by lifting the “earthy” end of R1 and connecting a multimeter (set to milliamps) between it and earth. When the set is turned on, the meter should show a siliconchip.com.au Photo Gallery: 1937 Healing 447M Manufactured by Healing in Melbourne in 1937, the Model 447M was housed in a stylish timber cabinet and tuned both the medium-wave broadcast band and the 6-18MHz shortwave band. The valve line-up was as follows: 6A8-G frequency changer, 6D6 IF amplifier, 75 audio amplifier/detector/AVC rectifier, 42 audio output and 80 rectifier. Photo: Historical Radio Society of Australia, Inc. reading of about 0.2mA and this reading should change slightly as you tune the set across the band. If this happens, it indicates that the local oscillator is working. Conversely, if there is no reading, it is likely that the 6AN7 is defective or there are shorted turns in the oscillator coil(s). If necessary, a 6AN7A valve may be substituted for a 6AN7 with no circuit changes. Don’t forget to resolder resistor R1’s lead to earth after removing the multimeter. If the local oscillator is working but the set still refuses to operate, try changing the 6N8. It’s worth noting that I find very few faulty valves and I probably average less than one replacement per set. Note too that some valves can become microphonic and you can quickly track down the culprit(s) by gently tapping each valve in turn with a pencil or the plastic handle of a screwdriver. If a valve is microphonic, it will produce a noise (possibly a “ringing” noise) when tapped. Valve sockets can also cause problems, For example, the contacts may be dirty or they may be loose and not making proper contact with the valve pins. In addition, the sockets and switches may need to be lubricated and cleaned with a proprietary contact cleaner. Other problems If someone before you has twiddled with the cores of the various coils, it may be necessary to re-align the set using a signal generator before it will operate. Other possible problems include faults inside the RF, oscillator and IF coils that cannot be determined by pure resistance measurements. Another trap to be aware of is that someone else may have replaced parts with incorrect values, or even installed parts in the wrong locations. As a result, simply checking the components may not show where the problem is. The way around this is to carefully check the receiver against the circuit diagram. Finally, more complex receivers can also be tested using the same techniques described here – it will just take longer. However, it’s best to start with the simpler broadcast-band radios first and then work your way up to more complicated units as you SC gain experience. June 2004  89 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 TV signal strength meter wanted I would like to know where I can buy a kit or a ready-made meter to measure signal strength for TV channels. My neighbour used one from his work to help me locate the best position for my TV antenna. It was quite a whizz-bang gadget, preset for all the TV channels, and he could tell me immediately the dB for all the channels. Have you people had experience with a simplified version of one of these? Also, where can I get the carrier frequency settings for all the TV channels? (G. B., Melbourne, Vic). • We have not produced a TV signal strength meter. Many installers find that a portable TV is more convenient. Not only does it give an indication of signal strength but it also shows the presence of ghosting and enables the antenna to be oriented for best reception. TV station frequencies can be found as a PDF file at: http://www.aba.gov.au/ broadcasters/television.htm Power reduction to derated transformers I want to ask if it is possible to use 40-0-40V 300VA transformers for the Mosfet amplifier published in SILICON CHIP, August 2001. This amplifier is essentially a revamp of the old EA Pro One amplifier. In both articles (EA & SILICON CHIP), the design specifies a 45-0-45V 300VA transformer. I have an old EA Pro One and want to restore with it 40-0-40V 300VA transformers. Can you estimate the output power with these transformers and if the 0.8V quiescent current set-up would be the same? (E. Z., via email). • Power is a square law. Since you are proposing to reduce the supply voltages by a factor of 12% (40/45 = 0.88), the power output will be reduced by 21% (0.79). This will be a barely audible difference of -1.02dB. The biasing will remain the same. Sniffer probe avoids crystal loading I have just successfully built the Low-Cost 50MHz Frequency Meter from the October 2003 issue (from a Jaycar kit). May I suggest a follow up article on using this meter, describing probes and servicing techniques for higher frequencies. In conversation with Bob Young (one of your contributors), I learnt that Bob described the construction and use of a “sniffer” probe for use around radio control transmitters that allows Phono Preamp For Surround Sound Amplifier I recently purchased a surround sound receiver amplifier and using it to watch and listen to movies and music DVDs is a real pleasure. My request relates to the missing phono input on the amplifier. I have a reasonable collection of LPs that I would like to occasionally listen to, even if only to amaze my two sons with the big black disks. Do you have any plans to design a phono preamplifier for a magnetic cartridge which would feed a line input on a hifi amplifier? For some 90  Silicon Chip reason, many hifi equipment manufacturers no longer include this in their designs and a project like this would be fun to make and extend the use of most modern hifi equipment. (J. C., via email). • Three designs are relevant: the Universal Preamplifier in April 1994; the RIAA Preamplifier in March 2002 (these are essentially the same circuit but have different PC boards); and the LP Doctor (includes click suppression) in January & February 2001. frequency measurements to be made without connection to the circuit under test, avoiding loading circuits that could give an invalid reading. Another useful probe would be an “active” probe that would increase both the input impedance and sensitivity, especially at the high end of the unit’s range. I am using a CRO probe with the Frequency Meter but have found that on probe setting ‘x1’ it loads the crystal oscillator circuit in the radio control receiver, causing it to cease operating while on ‘x10’ the reduced sensitivity means the meter reads “Await Signal”. (J. K., Broulee, NSW). • We showed how to make a sniffer coil on page 27 of the December 2003 issue. Also you might like to look at the active sniffer probe described in June & September 1988. When checking crystal oscillator circuits with a CRO probe, try connecting it via a 1kΩ or 2.2kΩ resistor. This can be enough to stop the probe capacitance from loading the crystal, while still letting enough signal through to let you make the measurement. It can be useful when using a scope too. Line level switcher wanted Has your magazine ever described a Line Level Switcher? I have purchased a mini stereo system and it only has one line input and no line output. I have a VCR, DVD, CD recorder, tape deck and a Mini-Disc recorder; as you can see, too many for one input. I would like these devices to go to the mini stereo system and also be able to record from one device to the other. (R. M., via email). • Have a look at the Video Switcher in the June 1992 issue. It can handle A/V signals from three sources. LEDs for an LCD video projector I was intrigued by your article on human-powered LED torches in the siliconchip.com.au February 2004 issue. I have been contemplating building a LED-based home LCD projector. Traditional projectors use very expensive and hot running lamps, necessitating special power supplies and cooling. LEDs seem an ideal solution, if they can be made bright and focused enough. Using this technology, it should be possible to build a projector for much less than current commercial units. Is this something that SILICON CHIP magazine could investigate? (J. H., via email). • LEDs have a very long way to go before they can replace the halogen lamps used in projectors. We doubt if they will ever be bright enough for that application. DIY humidity sensor for PICAXE datalogger I was very interested to read your project on the PICAXE Datalogger in the February 2004 issue. I have made enquiries about various types of sensors from some companies but have found that they are expensive and high end. Do you know of any publications for the enthusiast that explain how to make your own sensors – eg, relative humidity, leaf wetness, etc? (M. H., via email). • We do not have any information on DIY sensors although some clothes dryers have a humidity sensor based on horse hair. It may be possible to use such a sensor although we are inclined to think that it would be fairly imprecise in its action. Bigger bass for school PA system I have a question involving a 100V line PA system that is installed in a school sports hall with speakers down one side. A team wants to use them to play up-tempo music for warm-ups and maintaining training intensity. As the speakers are evenly spaced up and down the wall on one side of the courts, evenness of volume is OK but they lack the needed bass punch. So I would like to install a subwoofer that can be taken away when not required. Is it possible to insert a passive subwoofer crossover directly into the 100V line, feed the high-pass signal to the existing speakers and have the siliconchip.com.au Crossover Wanted For 2-Way Loudspeaker I have recently purchased a JV-80 loudspeaker kit from Jaycar Electronics and would like to know if it is possible to make a 2-way speaker using one of the tweeters (D26 NC15-06) and one of the woofers (P22 WP- 01) in a 35-litre enclosure. If so, can you tell me if it’s possible to use the crossover network (CS-2580) supplied with the kit, with suitable modification for a one tweeter and one woofer combination, or do I need to use a completely different circuit? Also, would one of the ports recommended for the JV-80 kit (ie, 66 x 140mm) be suitable for a 35-litre enclosure? (L. J., via email). low-pass signal feed a 100V to 8-ohm transformer and onto the sub? For a 100W amplifier, what size transformer would you recommend for the sub tap? Will different taps change the impedance and so the crossover frequency? Or do I need two 100V to 8-ohm transformers; one stepping down from 100V to ‘speaker level’, then through the crossover and, on the high-pass side, a second stepping it back up to 100V? Or is it best to have an electronic crossover at signal level and bi-amp it – one feeding the existing speakers and the other feeding the sub? Is there any problem with the sub amplifier output being stepped up to 100V and then back again at the subwoofer speaker? Are there any traps for someone who has enough knowledge to think they know what they are doing but not ELAN Audio The Leading Australian Manufacturer of Professional Broadcast Audio Equipment • It is certainly possible to build a 35-litre system with one of the woofers and a tweeter. It would then be a 4-ohm system, which may or may not be a problem for your amplifier. However, you cannot use the existing crossover since it is optimised for an 8-ohm system. As a stopgap, you could try connecting the woofer right across the full signal but still connect the tweeter via the existing crossover components. Nor can you just use one of the ports as is. The enclosure needs to be designed using a software program such as BassBox to calculate the port size. enough to know they actually don’t? Being a school, cost is going to be a factor so I’d like to go with the least expensive option that works. By the way, have you considered doing an article on 100V line-distributed PA systems? Ideally the article would at least cover the background of why 100V and why there are 70V and other voltage standards. (T. H., Calwell, ACT). • We would not try any passive subwoofer system. It would be better to take the 100V signal and feed it to a separate powered subwoofer. This would be much easier to set up and disconnect. You might like to have a look at the subwoofer controller project in the December 1995 issue. Thanks for your suggestion for an article on PA standards, etc. We have already briefly covered the subject in 2 Steel Court South Guildford Western Australia 6055 Phone 08 9277 3500 Fax 08 9478 2266 email poulkirk<at>elan.com.au www.elan.com.au RMA-02 Studio Quality High Power Stereo Monitor Amplifier Designed for Professional Audio Monitoring during Recording and Mastering Sessions The Perfect Power Amplifier for the 'Ultimate' Home Stereo System For Details and Price of the RMA-02 and other Products, Please contact Elan Audio June 2004  91 Notes & Errata SuperCharger, November & December 2002: with some 16VAC plugpacks, a high mains voltage condition may cause the transient voltage suppressor (TVS1) to conduct, blowing the fuse. To prevent this occurring, replace the SMCJ24A with the higher voltage SMCJ30A (Farnell Cat. 421-3580). Also, reduce the value of R19 from 9.1kΩ to 2.7kΩ and R20 from 1.3kΩ to 300Ω. A microcontroller firmware upgrade is necessary to accommodate these changes. An updated version (V1.1) is available from the SILICON CHIP website. Also, when charging six 16001800mAh cells in high ambient temperatures, the unit may overheat. The component most at risk is bridge rectifier (BR1). To reduce the temperature of the bridge, replace an article entitled Plastic Power PA Amplifier in the March 1997 issue. Bypass capacitors for Multi-Spark CDI I have a problem with the MultiSpark CDI system featured in “Electronic Projects for Cars, Volume 2”. Here in Thailand I cannot get the 10µF 63V MKT capacitors for decoupling the DC supply to the transformer (see page 82, Fig.2). Is it OK to change these to 1µF 63V MKT? (P. A., Amper Muang, Thailand). • 10µF capacitors must be used rather than 1µF. These are MKT types the KBL404 device with a GBU4D (Farnell Cat. 330-7256). The GBU4D has a hole in the centre that allows attachment of a small “micro U” style heatsink (eg, Altronics Cat. H-0630). Secure the heatsink to the bridge using an M3 x 10mm screw, nut and washer. Note that you’ll need to cut or file off the lower left fin of the heatsink so that it clears the AC input socket. Use heatsink compound on all surfaces to aid heat transfer. Note also that when in position, the heatsink will obscure the fourth lamp position on the rear panel, so if you’ve yet to build the unit, omit the fourth (innermost) lamp. Finally, to further decrease heat sensitivity, we recommend replacing the 2.5A polyswitch (PTC1) with a higher current, 3A device. A suitable replacement is the RUE300 (Farnell Cat. 608-956 or Altronics R-4561A). and are necessary for correct bypassing of the high frequency switching artefacts on the DC supply. Alternatively, low-ESR 10µF 25V electrolytics could be used. Farnell Electronics sell these MKT capacitors, Cat. 814-155. Refer to: www.premierfarnell.com Dimmer for 900W incandescent lamp load I have a 900W incandescent lamp load and I wish to place a dimmer on the circuit. The existing switch is on a multi-gang plate so the bulky commercial dimmers are not an option. My local electronics retailer in Adelaide suggested using a linear pot and a 15A Triac. I purchased these parts along with a heatsink but I am confident that more components are needed. So I need a circuit diagram and parts list to do the job. (S. H., via email). • A 15A Triac is not robust enough for such a load as lamp failure will cause the Triac to blow. Have a look at the High Power Dimmer in the August 1994 issue. Increased rating for electronic load In the 50W Electronic Load (SILICON CHIP, September 2002), could the addition of an extra MOSFET in the output stage increase the current capability to 20A? (B. P., Palmerston North, New Zealand). • Increasing the power handling capability of the electronic load (while maintaining reliability) is a little tricky. A second MOSFET in parallel with the existing device will increase power handing. However, it’s not easy to get the two devices to share the load equally. In fact, we built a 100W prototype using multiple devices but eventually had to scrap the idea, as very large (and expensive) source resistors were required to force equal current sharing. Having said that, you could try one of these ideas: (1) use a much larger MOSFET (such as one of the “DICE” packaged devices); (2) try MOSFETS specified for audio use. These are designed for use in their linear regions, so are likely to work better in this application; and (3) use matched SC MOSFETs. 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. 92  Silicon Chip siliconchip.com.au MARKET CENTRE Cash in your surplus gear. Advertise it here in Silicon Chip. CLASSIFIED ADVERTISING RATES Advertising rates for this page: Classified ads: $20.00 (incl. GST) for up to 20 words plus 66 cents for each additional word. Display ads: $33.00 (incl. GST) per column centimetre (max. 10cm). Closing date: five weeks prior to month of sale. To run your classified ad, print it clearly in the space below or on a separate sheet of paper, fill out the form & send it with your cheque or credit card details to: Silicon Chip Classifieds, PO Box 139, Collaroy, NSW 2097. Alternatively, fax the details to (02) 9979 6503 or send an email to silchip<at>siliconchip.com.au Taxation Invoice ABN 49 003 205 490 _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ Enclosed is my cheque/money order for $­__________ or please debit my  Bankcard    Visa Card    Master Card Card No. Signature­­­­­­­­­­­­__________________________ Card expiry date______/______ Name _____________________________________________________ Street _____________________________________________________ Suburb/town ___________________________ Postcode______________ Phone:_____________ Fax:_____________ Email:__________________ siliconchip.com.au FOR SALE UNIVERSAL DEVICE PROGRAMMER: Low cost, high performance, 48-pin, works in DOS or Windows incl. NT/2000. $1100. Universal EPROM programmer $374.00. Also adaptors, (E)EPROM, PIC, 8051 programmers, EPROM simulator and eraser. Dunfield C Compilers: Everything you need to develop C and ASM software for 68HC08, 6809, 68HC11, 68HC12, 68HC16, 8051/52, 8080/85, 8086, 8096 or AVR: $198 each. Demo disk available. ImageCraft C Compilers: 32-bit Windows IDE and compiler. For AVR, 68HC­08, 68HC11, 68HC12, 68HC16. from $330.00 Atmel Flash CPU Programmer: Handles the 89Cx051, 89C5x, 89Sxx in both DIP and PLCC44 and some AVR’s, most 8-pin EEPROMS. Includes socket for serial ISP cable. $220, $11 p&p. SOIC adaptors: 20 pin $132.00, 14 pin $126.50, 8 pin $121.00. Full details on web site. Credit cards accepted. GRANTRONICS PTY LTD, PO Box 275, Wentworthville 2145. (02) 9896 7150 or http://www.grantronics.com.au PCBs MADE, ONE OR MANY. Any format, hobbyists welcome. Sesame Elec­tronics (02) 9593 1025. sesame777<at>optusnet.com.au http://sesame_elec.tripod.com MAGGYLAMPS: We have a full range of magnifying lamps, ex-stock, Australianmade and imported. Ask for catalogue. Ph 1300 788 239. VALVE TESTER: would the person from NSW who answered my ad in the February issue please contact me again. Lost contact data. Alan 03 9460 3091. 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 June 2004  93 New New New Mark22-SM Slimline Mini FM R/C Receiver • • • • • Satellite TV Reception International satellite TV reception in your home is now affordable. Send for your free info pack containing equipment catalog, satellite lists, etc or call for appointment to view. We can display all satellites from 76.5° to 180°. AV-COMM P/L, 24/9 Powells Rd, Brookvale, NSW 2100. Tel: 02 9939 4377 or 9939 4378. Fax: 9939 4376; www.avcomm.com.au 6 Channels 10kHz frequency separation Size: 55 x 23 x 20mm Weight: 25gm Modular Construction Price: $A129.50 with crystal JACKSON BROS JACKSON OF THE UK IS BACK Highest quality products made by UK Craftsmen Electronics PO Box 580, Riverwood, NSW 2210. Ph/Fax (02) 9533 3517 email: youngbob<at>silvertone.com.au Website: www.silvertone.com.au Coax Cable & Connectors   Variable and trimmer capacitors, reduction drives, dials, ceramic stand-offs Cable OD (mm) dB/m 150 MHz 2400 MHz $/m N-Type RPSMA or RGTNC Pigtails Web: Email: Tel: CFD-200 5 0.130 0.550 $2.50 ($1.50 *) CHARLES I COOKSON PTY LTD GPO BOX 812, ADELAIDE, SA 5001 Tel: (08) 8235 0744 Fax: (08) 8356 3652 FreeFax: 1800 673355 (Within Australia) Email: jackson<at>homeplanet.com.au ALL MAJOR CREDIT CARDS ACCEPTED SOLE AGENTS FOR AUSTRALIA AND NEW ZEALAND CFD-400 10 0.050 0.220 $4.00 ($2.00 *) Connectors $7.00 $7.00 ($3.00 *) ($4.00 *) $10.00 n/a ($5.00 *) email * = bulk price www.freenet-antennas.com sales<at>freenet-antennas.com +61 (8) 9319 1720 MINIWATT TECHNICAL DATA VALVES BOOK and valves 6BM8 12AX7 12AU7 6U8 6DX8 and more $120.00 the lot. Ben 03 5775 1174. USB KITS: Stepper Motor Controller, USB PIO Interface, DTMF Transceiver, Thermometer, DDS HF Generator, 94  Silicon Chip The Most Flexible Development board around. Based on the PIC16F877. The development board can be used with a wide variety of PIC Micros including the PIC18F452. Adaptors avaliable to use the 8, 18, 28-pin PIC Micros. ICD 2 connector allows In-circuit programming / Debugging with Microchip’s ICD2. Uncommited I/O ports allow for your own connection configuration to each device and also to external circuits. Onboard parallel port programmer allows programming of the PIC while still connected to the circuits. Other optional extras available.Connection to each circuit module or extrenal circuit is made via 10-way IDC cables provided. The possibilities are endless. Student/School discounts available. For more information . . . Visit: www.microbyte.com.au Phone: (03) 9378 4288 Email: info<at>microbyte.com.au Full range now available off the shelf in Australia CATALOGUES AND PRICE LISTS NOW AVAILABLE     Type Development / Training Board For the PIC Micro Compass, 4-Channel Voltmeter, I/O Relay Card. Also available: Digital Oscilloscope, Temperature Loggers, VHF Receivers and USB Active X (and USBDOS.exe file) to control our kits from your application. www.ar.com.au/~softmark sPlan Windows electronic schematic software and Sprint Layout Windows PCB layout software are feature packed but low in price. Pixel Programmable Controller with 4 analog inputs, 8 digital inputs and 8 relay outputs. Can use a 28A or 28X Picaxe. Programmed in Basic or Flow chart. Labjack USB Data Acquisition Mod- & MADE TO ORDER PCBs For more details: www.acetronics.com.au Phone (02) 9600 6832 email: acetronics<at>acetronics.com.au ule features 8 12bit analog inputs, 20 digital I/O, 2 analog outputs and high speed counter. Free software, Labview driver and ActiveX component. DAS005 Parallel Port Data Acquisition Module features 8 12bit Analog inputs, 4 Digital I/Ps & 4 Digital O/Ps. Free windows software and source code. Dual Relay Modules suitable for TTL and Open Collector Outputs. Programmers for Atmel and PIC microcontrollers. Stepper Motor and Servo Motor controller kits. Switch Mode and Linear Power Supplies and DC-DC convertors. Full details and credit card ordering available at: www.oceancontrols.com.au S-Video . . . Video . . . Audio . . . VGA distribution amps, splitters, standards converters, tbc’s, switchers, cables, etc, & price list: www.questronix.com.au WEATHER STATIONS: windspeed & direction, inside temperature, outside temperature & windchill. Records highs & lows with time and date as they occur. siliconchip.com.au Do You Eat, Breathe and Sleep Technology? Management & Sales Positions We are a rapidly growing, Australian-owned international retailer with more than 30 stores in Australia and we have a growing expansion program to open many more, so we need dedicated individuals to join our team to help achieve our goals. If you are customer focused, have an eye for detail, empathy for the products we sell and have an interest or qualifications in electronics, we want to meet you. Career opportunities with full training are available now if you have the drive and ambition to make your future with Jaycar. We offer a competitive salary, sales commission and many other benefits. To apply for these positions please send your C.V. indicating the role you are interested in to the address shown below. Retail Operations Manager Jaycar Electronics Pty. Ltd. P.O. Box 6424 Silverwater NSW 1811 Fax: (02) 9741-8500 Email: jobs<at>jaycar.com.au Advertising Index Acetronics....................................94 Jaycar Electronics is an equal opportunity employer and actively promotes staff from within the organisation. Altronics................................. 68-70 ATA...............................................83 Av-Comm.....................................94 Carba-Tec Tools...........................95 Dick Smith Electronics........... 20-23 Eco Watch....................................95 Elan Audio....................................91 Elexol...........................................57 FreeNet Antennas........................94 Gadget Central...........................IFC Grantronics...................................93 Foam surrounds,voice coils,cones and more Original parts for Dynaudio,Tannoy and others Expert speaker repairs – 20 years experience Australian agents for products Trade welcome – email for your user ID Phone (03) 9682 2487 speakerbits.com.au Building speaker boxes? Mounting electrical components onto solid timber? You may need the Carba–tecTOOLS FOR WOOD catalogue!! We have Australia’s largest range of woodworking handtools & machinery. Please contact us for your FREE 220 page colour catalogue or come in & see us at: 113 STATION RD, AUBURN 2144 NEW ADDRESS! PH: 9648 6446; FAX 9648 6443; www.carbatec.com.au Amazing LEDs at amazing prices! • Superbright 5mm LEDs from $0.35 each • 2-chip, 5mm, 40mA megabrights from $1.10 each • 4-chip, 80mA megabrights from $1.25 each LED torches • pet flashers • lithium batteries • other stuff www.ledsales.com.au TAIG MACHINERY Micro Mini Lathes and Mills From $489.00 Harbuch Electronics.....................79 Hy-Q International........................81 Instant PCBs................................95 Jackson Bros................................94 Jaycar .......................... 45-52,81,95 JED Microprocessors................5,81 Kalex............................................77 MicroByte Electronics...................94 Microgram Computers....................3 MicroZed Computers....................58 Newtek Sales...............................57 Oatley Electronics..........................7 Ozitronics.....................................83 Prime Electronics.........................19 Quest Electronics....................81,94 RCS Radio...................................96 Optional rainfall and PC interface. Used by government departments, farmers, pilots and weather enthusiasts. Other models with barometric pressure, humidity, dew point, solar radiation, UV, leaf wetness, etc. Just phone, fax or write for our FREE catalog and price list. Eco Watch phone: (03) 9761 7040; fax: (03) 9761 7050; Unit 5, 17 Southfork Drive, Kilsyth, Vic. 3137. ABN 63 006 399 480. KITS KITS AND MORE KITS! Check ’em out at www.ozitronics.com 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 siliconchip.com.au RF Probes....................................77 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 Silicon Chip Binders.....................33 Silicon Chip Bookshop..........96,IBC SC Car Projects Book..............OBC Silicon Chip Subscriptions...........53 Silicon Chip Silvertone Electronics..................94 Do you have a good circuit idea? If so, sketch it out, write a brief description of its operation & send it to us. Provided your idea is workable & original, we’ll publish it in Circuit Notebook & you’ll make some money. We pay up to $60 for a good circuit so send your idea to: Taig Machinery.............................95 Circuit Ideas Wanted Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. Soundlabs Group.........................81 SPLat Controls.............................75 Telelink Communications.............81 WIA..............................................81 ____________________________ PC Boards Printed circuit boards for SILICON CHIP projects are made by: RCS Radio Pty Ltd. Phone (02) 9738 0330. Fax (02) 9738 0334. June 2004  95 ALL S ILICON C HIP SUBSCRIBERS – PRINT, OR BOTH – AUTOMATICALLY QUALIFY FOR A REFERENCE $ave 10%ONLINE DISCOUNT ON ALL BOOK OR PARTSHOP PURCHASES. CHIP BOOKSHOP 10% (Does not apply to subscriptions) SILICON For the latest titles and information, please refer to our website books page: www.siliconchip.com.au/Shop/Books PIC MICROCONTROLLERS: know it all SELF ON AUDIO Multiple authors $85.00 The best of subjects Newnes authors have written over the past few years, combined in a one-stop maxi reference. Covers introduction to PICs and their programming in Assembly, PICBASIC, MBASIC & C. 900+ pages. PROGRAMMING and CUSTOMIZING THE PICAXE By David Lincoln (2nd Ed, 2011) $65.00* A great aid when wrestling with applications for the PICAXE See series of microcontrollers, at beginner, intermediate and Review April advanced levels. Every electronics class, school and library should have a copy, along with anyone who works with PICAXEs. 300 pages in paperback. 2011 PIC IN PRACTICE by D W Smith. 2nd Edition - published 2006 $60.00* by Douglas Self 2nd Edition 2006 $69.00* A collection of 35 classic magazine articles offering a dependable methodology for designing audio power amplifiers to improve performance at every point without significantly increasing cost. Includes compressors/limiters, hybrid bipolar/FET amps, electronic switching and more. 467 pages in paperback. SMALL SIGNAL AUDIO DESIGN By Douglas Self – First Edition 2010 $95.00* The latest from the Guru of audio. Explains audio concepts in easy-to-understand language with plenty of examples and reasoning. Inspiration for audio designers, superb background for audio enthusiasts and especially where it comes to component peculiarities and limitations. Expensive? Yes. Value for money? YES! Highly recommended. 558 pages in paperback. Based on popular short courses on the PIC, for professionals, students and teachers. Can be used at a variety of levels. An ideal introduction to the world of microcontrollers. 255 pages in paperback. PIC MICROCONTROLLER – your personal introductory course By John Morton 3rd edition 2005. $60.00* A unique and practical guide to getting up and running with the PIC. It assumes no knowledge of microcontrollers – ideal introduction for students, teachers, technicians and electronics enthusiasts. Revised 3rd edition focuses entirely on re-programmable flash PICs such as 16F54, 16F84 12F508 and 12F675. 226 pages in paperback. AUDIO POWER AMPLIFIER DESIGN HANDBOOK by Douglas Self – 5th Edition 2009 $85.00* "The Bible" on audio power amplifiers. Many revisions and updates to the previous edition and now has an extra three chapters covering Class XD, Power Amp Input Systems and Input Processing and Auxiliarly Subsystems. Not cheap and not a book for the beginner but if you want the best reference on Audio Power Amps, you want this one! 463 pages in paperback. DVD PLAYERS AND DRIVES by K.F. Ibrahim. Published 2003. $71.00* OP AMPS FOR EVERYONE By Bruce Carter – 4th Edition 2013 $83.00* This is the bible for anyone designing op amp circuits and you don't have to be an engineer to get the most out of it. It is written in simple language but gives lots of in-depth info, bridging the gap between the theoretical and the practical. 281 pages, A guide to DVD technology and applications, with particular focus on design issues and pitfalls, maintenance and repair. Ideal for engineers, technicians, students of consumer electronics and sales and installation staff. 319 pages in paperback. by Sanjaya Maniktala, Published April 2012. $83.00 Thoroughly revised! The most comprehensive study available of theoretical and practical aspects of controlling and measuring EMI in switching power supplies. Subtitled Exploring the PIC32, a Microchip insider tells all on this powerful PIC! Focuses on examples and exercises that show how to solve common, real-world design problems quickly. Includes handy checklists. FREE CD-ROM includes source code in C, the Microchip C30 compiler, and MPLAB SIM. 400 pages paperback. By Garry Cratt – Latest (7th) Edition 2008 $49.00 Written in Australia, for Australian conditions by one of Australia's foremost satellite TV experts. If there is anything you wanted to know about setting up a satellite TV system, (including what you can't do!) it's sure to be covered in this 176-page paperback book. See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* PRACTICAL GUIDE TO SATELLITE TV See Review March 2010 ELECTRIC MOTORS AND DRIVES By Austin Hughes & Bill Drury - 4th edition 2013 $59.00* This is a very easy to read book with very little mathematics or formulas. It covers the basics of all the main motor types, DC permanent magnet and wound field, AC induction and steppers and gives a very good description of how speed control circuits work with these motors. Soft covers, 444 pages. NEWNES GUIDE TO TV & VIDEO TECHNOLOGY By KF Ibrahim 4th Edition (Published 2007) $49.00 It's back! Provides a full and comprehensive coverage of video and television technology including HDTV and DVD. Starts with fundamentals so is ideal for students but covers in-depth technologies such as Blu-ray, DLP, Digital TV, etc so is also perfect for engineers. 600+ pages in paperback. RF CIRCUIT DESIGN by Chris Bowick, Second Edition, 2008. $63.00* The classic RF circuit design book. RF circuit design is now more important that ever in the wireless world. In most of the wireless devices that we use there is an RF component – this book tells how to design and integrate in a very practical fashion. 244 pages in paperback. AC MACHINES By Jim Lowe Published 2006 $66.00* Applicable to Australian trades-level courses including NE10 AC Machines, NE12 Synchronous Machines and the AC part of NE30 Electric Motor Control and Protection. Covering polyphase induction motors, singlephase motors, synchronous machines and polyphase motor starting. 160 pages in paperback. PRACTICAL VARIABLE SPEED DRIVES & POWER ELECTRONICS Se e by Malcolm Barnes. 1st Ed, Feb 2003. $73.00* Review An essential reference for engineers and anyone who wishes to design or use variable speed drives for induction motors. 286 pages in soft cover. Feb 2003 BUILD YOUR OWN ELECTRIC MOTORCYCLE PRACTICAL RF HANDBOOK by Carl Vogel. Published 2009. $40.00* by Ian Hickman. 4th edition 2007 $61.00* A guide to RF design for engineers, technicians, students and enthusiasts. Covers key topics in RF: analog design principles, transmission lines, couplers, transformers, amplifiers, oscillators, modulation, transmitters and receivers, propagation and antennas. 279 pages in paperback. Alternative fuel expert Carl Vogel gives you a hands-on guide with the latest technical information and easy-to-follow instructions for building a two-wheeled electric vehicle – from a streamlined scooter to a full-sized motorcycle. 384 pages in soft cover. *NOTE: ALL PRICES ARE PLUS P&P – AUSTRALIA ONLY: $10.00 per order; NZ – $AU12.00 PER BOOK; REST OF WORLD $AU18.00 PER BOOK To Place Your Order: INTERNET (24/7) PAYPAL (24/7) eMAIL (24/7) www.siliconchip. com.au/Shop/Books Use your PayPal account silicon<at>siliconchip.com.au silicon<at>siliconchip.com.au with order & credit card details FAX (24/7) MAIL (24/7) Your order and card details to Your order to PO Box 139 Collaroy NSW 2097 (02) 9939 2648 with all details PHONE – (9-5, Mon-Fri) Call (02) 9939 3295 with with order & credit card details You can also order and pay for books by cheque/money order (Mail Only). Make cheques payable to Silicon Chip Publications. ALL TITLES SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST ALL S ILICON C HIP SUBSCRIBERS – PRINT, OR BOTH – AUTOMATICALLY QUALIFY FOR A REFERENCE $ave 10%ONLINE DISCOUNT ON ALL BOOK OR PARTSHOP PURCHASES. CHIP BOOKSHOP 10% (Does not apply to subscriptions) SILICON For the latest titles and information, please refer to our website books page: www.siliconchip.com.au/Shop/Books PIC MICROCONTROLLERS: know it all SELF ON AUDIO Multiple authors $85.00 The best of subjects Newnes authors have written over the past few years, combined in a one-stop maxi reference. Covers introduction to PICs and their programming in Assembly, PICBASIC, MBASIC & C. 900+ pages. PROGRAMMING and CUSTOMIZING THE PICAXE By David Lincoln (2nd Ed, 2011) $65.00* A great aid when wrestling with applications for the PICAXE See series of microcontrollers, at beginner, intermediate and Review April advanced levels. Every electronics class, school and library should have a copy, along with anyone who works with PICAXEs. 300 pages in paperback. 2011 PIC IN PRACTICE by D W Smith. 2nd Edition - published 2006 $60.00* by Douglas Self 2nd Edition 2006 $69.00* A collection of 35 classic magazine articles offering a dependable methodology for designing audio power amplifiers to improve performance at every point without significantly increasing cost. Includes compressors/limiters, hybrid bipolar/FET amps, electronic switching and more. 467 pages in paperback. SMALL SIGNAL AUDIO DESIGN By Douglas Self – First Edition 2010 $95.00* The latest from the Guru of audio. Explains audio concepts in easy-to-understand language with plenty of examples and reasoning. Inspiration for audio designers, superb background for audio enthusiasts and especially where it comes to component peculiarities and limitations. Expensive? Yes. Value for money? YES! Highly recommended. 558 pages in paperback. Based on popular short courses on the PIC, for professionals, students and teachers. Can be used at a variety of levels. An ideal introduction to the world of microcontrollers. 255 pages in paperback. PIC MICROCONTROLLER – your personal introductory course By John Morton 3rd edition 2005. $60.00* A unique and practical guide to getting up and running with the PIC. It assumes no knowledge of microcontrollers – ideal introduction for students, teachers, technicians and electronics enthusiasts. Revised 3rd edition focuses entirely on re-programmable flash PICs such as 16F54, 16F84 12F508 and 12F675. 226 pages in paperback. AUDIO POWER AMPLIFIER DESIGN HANDBOOK by Douglas Self – 5th Edition 2009 $85.00* "The Bible" on audio power amplifiers. Many revisions and updates to the previous edition and now has an extra three chapters covering Class XD, Power Amp Input Systems and Input Processing and Auxiliarly Subsystems. Not cheap and not a book for the beginner but if you want the best reference on Audio Power Amps, you want this one! 463 pages in paperback. DVD PLAYERS AND DRIVES by K.F. Ibrahim. Published 2003. $71.00* OP AMPS FOR EVERYONE By Bruce Carter – 4th Edition 2013 $83.00* This is the bible for anyone designing op amp circuits and you don't have to be an engineer to get the most out of it. It is written in simple language but gives lots of in-depth info, bridging the gap between the theoretical and the practical. 281 pages, A guide to DVD technology and applications, with particular focus on design issues and pitfalls, maintenance and repair. Ideal for engineers, technicians, students of consumer electronics and sales and installation staff. 319 pages in paperback. by Sanjaya Maniktala, Published April 2012. $83.00 Thoroughly revised! The most comprehensive study available of theoretical and practical aspects of controlling and measuring EMI in switching power supplies. Subtitled Exploring the PIC32, a Microchip insider tells all on this powerful PIC! Focuses on examples and exercises that show how to solve common, real-world design problems quickly. Includes handy checklists. FREE CD-ROM includes source code in C, the Microchip C30 compiler, and MPLAB SIM. 400 pages paperback. By Garry Cratt – Latest (7th) Edition 2008 $49.00 Written in Australia, for Australian conditions by one of Australia's foremost satellite TV experts. If there is anything you wanted to know about setting up a satellite TV system, (including what you can't do!) it's sure to be covered in this 176-page paperback book. See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* PRACTICAL GUIDE TO SATELLITE TV See Review March 2010 ELECTRIC MOTORS AND DRIVES By Austin Hughes & Bill Drury - 4th edition 2013 $59.00* This is a very easy to read book with very little mathematics or formulas. It covers the basics of all the main motor types, DC permanent magnet and wound field, AC induction and steppers and gives a very good description of how speed control circuits work with these motors. Soft covers, 444 pages. NEWNES GUIDE TO TV & VIDEO TECHNOLOGY By KF Ibrahim 4th Edition (Published 2007) $49.00 It's back! Provides a full and comprehensive coverage of video and television technology including HDTV and DVD. Starts with fundamentals so is ideal for students but covers in-depth technologies such as Blu-ray, DLP, Digital TV, etc so is also perfect for engineers. 600+ pages in paperback. RF CIRCUIT DESIGN by Chris Bowick, Second Edition, 2008. $63.00* The classic RF circuit design book. RF circuit design is now more important that ever in the wireless world. In most of the wireless devices that we use there is an RF component – this book tells how to design and integrate in a very practical fashion. 244 pages in paperback. AC MACHINES By Jim Lowe Published 2006 $66.00* Applicable to Australian trades-level courses including NE10 AC Machines, NE12 Synchronous Machines and the AC part of NE30 Electric Motor Control and Protection. Covering polyphase induction motors, singlephase motors, synchronous machines and polyphase motor starting. 160 pages in paperback. PRACTICAL VARIABLE SPEED DRIVES & POWER ELECTRONICS Se e by Malcolm Barnes. 1st Ed, Feb 2003. $73.00* Review An essential reference for engineers and anyone who wishes to design or use variable speed drives for induction motors. 286 pages in soft cover. Feb 2003 BUILD YOUR OWN ELECTRIC MOTORCYCLE PRACTICAL RF HANDBOOK by Carl Vogel. Published 2009. $40.00* by Ian Hickman. 4th edition 2007 $61.00* A guide to RF design for engineers, technicians, students and enthusiasts. Covers key topics in RF: analog design principles, transmission lines, couplers, transformers, amplifiers, oscillators, modulation, transmitters and receivers, propagation and antennas. 279 pages in paperback. Alternative fuel expert Carl Vogel gives you a hands-on guide with the latest technical information and easy-to-follow instructions for building a two-wheeled electric vehicle – from a streamlined scooter to a full-sized motorcycle. 384 pages in soft cover. *NOTE: ALL PRICES ARE PLUS P&P – AUSTRALIA ONLY: $10.00 per order; NZ – $AU12.00 PER BOOK; REST OF WORLD $AU18.00 PER BOOK To Place Your Order: INTERNET (24/7) PAYPAL (24/7) eMAIL (24/7) www.siliconchip. com.au/Shop/Books Use your PayPal account silicon<at>siliconchip.com.au silicon<at>siliconchip.com.au with order & credit card details FAX (24/7) MAIL (24/7) Your order and card details to Your order to PO Box 139 Collaroy NSW 2097 (02) 9939 2648 with all details PHONE – (9-5, Mon-Fri) Call (02) 9939 3295 with with order & credit card details You can also order and pay for books by cheque/money order (Mail Only). Make cheques payable to Silicon Chip Publications. ALL TITLES SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST