Fullscreen HTML5Med Res (??MB)HTML4

SILICON CHIP Australia’s World-Class Electronics Magazine! MARCH 2005 7 $ 90* INC GST NZ $ 8 75 INC GST PRINT POST APPROVED - PP255003/01272 ISSN 1030-2662 03 9 771030 266001 Serious training . . . or just for fun! POOL LAP COUNTER Pro Sports Scoreboard siliconchip.com.au Tuned Loop AM Antenna Dirt Cheap UV Eraser March 2005  1 SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.jaycar.com.au Contents Vol.18, No.3; March 2005 www.siliconchip.com.au FEATURES    8 The Revolution In Car Instruments Find out what’s in store for future dashboards – by Julian Edgar 32 The Start Of Colour TV In Australia, Pt.1 Colour TV is now 30 years old in Australia. Here’s a nostalgic look at the way things were back in 1975 – by Keith Walters 83 Build Yourself A Windmill Generator, Pt.4 Fourth and final article looks at propeller and mast options and describes further refinements for the alternator – by Glenn Littleford Professional Sports Scoreboard – Page 14. PROJECTS TO BUILD 14 Build A Professional Sports Scoreboard, Pt.1 It features big, bright LED displays and is controlled by an easy-to-operate wireless console. Modular construction makes it easy to build – by Jim Rowe 38 A Lap Counter For Swimming Pools Do you swim laps to keep in shape? This simple Picaxe-powered counter will keep track of the number of laps you’ve done – by Rick Walters 64 Inductance & Q-Factor Meter; Pt.2 Second article has all the construction details – by Leonid Lerner Lap Counter For Swimming Pools – Page 38. 74 Shielded Loop Antenna For AM Radios Dramatically improve your AM reception with this tuned loop antenna. It’s just the shot for remote areas & for minimising interference – by David Whitby 80 A Cheap UV EPROM Eraser An “anti-bacterial” toothbrush holder, a single capacitor and a simple IC carrier are all you need for a fully-functioning EPROM eraser – by Barry Hubble 92 Sending Picaxe Data Over 477MHz UHF CB Interested in sending digital data over UHF CB? That’s just one more thing you can do with a Picaxe – by Stan Swan SPECIAL COLUMNS 48 Serviceman’s Log Just knock but do it quietly – by the TV Serviceman 70 Circuit Notebook (1) Headlight Reminder; (2) El Cheapo Cable Tester; (3) Aviation Intercom; (4) Touch Lamp Remote Pad; (5) Simple Under-Voltage Cutout; (6) Reverse Polarity Protector; (7) Picaxe-Based Freezer Thermostat Shielded Loop Antenna For AM Radios – Page 74. 88 Salvage It! A $10 lathe & drill press tachometer – by Julian Edgar 96 Vintage Radio The Astor AJS: an economy universal car radio – by Rodney Champness DEPARTMENTS   2   4 13 46 61 Publisher’s Letter Mailbag Order Form Book Review Product Showcase siliconchip.com.au 102 105 108 111 Ask Silicon Chip Notes & Errata Market Centre Ad Index $10 Lathe/Drill Press Tachometer – Page 88. March 2005  1 SILICON CHIP www.siliconchip.com.au Publisher & Editor-in-Chief Leo Simpson, B.Bus., FAICD Production Manager Greg Swain, B.Sc.(Hons.) Technical Editor Peter Smith Technical Staff John Clarke, B.E.(Elec.) Ross Tester Jim Rowe, B.A., B.Sc, VK2ZLO Reader Services Ann Jenkinson Advertising Enquiries Phil Benedictus, Laurence Smith Benedictus Smith Pty Ltd Phone (02) 9211 9792 Fax: (02) 9211 0068 info<at>benedictus-smith.com Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Julian Edgar, Dip.T.(Sec.), B.Ed, Grad.Dip.Jnl Mike Sheriff, B.Sc, VK2YFK Stan Swan SILICON CHIP is published 12 times a year by Silicon Chip Publications Pty Ltd. ACN 003 205 490. ABN 49 003 205 490 All material copyright ©. No part of this publication may be reproduced without the written consent of the publisher. Printing: Hannanprint, Noble Park, Victoria. Distribution: Network Distribution Company. Subscription rates: $83.00 per year in Australia. For overseas rates, see the subscription page in this issue. Editorial office: Unit 8, 101 Darley St, Mona Vale, NSW 2103. Postal address: PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 9979 5644. Fax (02) 9979 6503. E-mail: silchip<at>siliconchip.com.au Publisher’s Letter Desalination a sensible approach for Perth’s water supply This summer has certainly highlighted the ongoing water shortages faced by most Australians, whether they live in the cities or rural areas. One way or another, we need more fresh water, whether it is obtained by more careful use of our existing limited water resources or by obtaining new sources. For the cities, the problems are possibly more urgent than in rural areas which are always subject to periods of drought. Perth has the most pressing problems, followed by Sydney, Melbourne and Adelaide. Perth has had declining rainfall over the last 30 years or so and has much reduced run-off into its dams. So Perth is taking the immediate approach of building a sea-water desalination plant, located next to the Kwinana power station. This makes sense, since it is close to the sea and the power source. The plant will use the reverse osmosis process whereby sea-water under high pressure is applied to semi-permeable membranes to remove salt and other dissolved solids. Reverse osmosis is the favoured process because it is one of the most energy efficient, although all desalination processes use large amounts of energy – hence the need to site the plant next to a power station. Perth’s proposed plant has an annual capacity of 45 gigalitres or 130 million litres/day. It is estimated to cost $346 million to build and $24 million a year to run. That sounds like a lot of money but it pales into insignificance compared to the much higher cost to build the mooted pipe-line or canal from the Kimberley region in the north of Western Australia down to Perth. Not only will it cost billions to build such a pipeline but it will need some very big pumping stations to get the water from the Kimberley down to Perth. Projections by Perth’s Water Corporation indicate that the energy cost for water from the desalination plant will be 5kWh/litre while that via the pipeline will be 15kWh/litre. Compare that with the price typically charged to domestic consumers in Australian cities – around $1 per thousand litres – and you wonder if our water shortage problems would suddenly disappear if the present water price was doubled! Really, when you think about the large energy cost of our present water supplies, for pumping, filtering, chlorination (don’t forget the high energy cost of chlorine production), fluoridation and so on, we should be making every attempt to be frugal in water use. And maybe the water authorities could do much to foster this by increasing the price! No doubt there will be many people who would be opposed to any increase in price for water but let’s face it, it is the most effective measure, requiring no new technology, no heavy consumption restrictions and no need for draconian policing – you use the water, you pay. Leo Simpson ISSN 1030-2662 * Recommended and maximum price only. 2  Silicon Chip siliconchip.com.au Amazing March Mega-Specials from 12v Mini PC A tiny barebones PC that is perfect for the boat, car, or any space critical situation. MicroGram f NEW! FireWire 800 Card RAID Unit Guard against hard drive failure. Provides hot-swap and auto-rebuild of failed drives without downtime. Cat 2874-7 $779 PCMCIA to Serial Add two serial ports to your notebook. Cat 2726-7 $269 Add high speed FireWire B to your PC with this PCI card. Also has a legacy FireWire 400 port. Cat 2998-7 $129 This mini barebones PC is based on the VIA Eden processor and motherboard. It can operate on 12v or 240v making it ideal for use in boats or cars. A fanless design ensures silent operation. The case measures only 49 x 220 x 165mm. It can take a 2.5" laptop hd or CF card, other devices such as a CDROM can be attached via USB. The integrated motherboard includes VGA and LAN. Cat 1150-7 $729 Macro Stick Fingerprint Reader Provide secure access to a PC by using fingerprints for authentication. Connects to the PC via USB. Cat 9237-7 $199 Hard Disk Restore Card Restore the PC hard disk to its previous state on restart. Perfect for Internet cafes, schools, etc. Cat 17079-7 $139 16 programmable keys that store up to 1000 keystrokes. It is designed to sit above the function keys on a standard keyboard. Cat 15131-7 $299 RFID Controller Suitable for RFID security applications. RFID readers, electronic door locks, alarms, can all be attached to this unit. Cat 1008179-7 $269 USB to 5.1 Sound xD Card Reader An 8 in 1 memory card reader that reads the most common cards used today. Cat 6786-7 $49 Extend USB 50m $999 Use inexpensive network cable (not included) to extend any USB 1.1 device up to 50m from a PC. Cat 11666-7 $105 Video to VGA Display any Composite or S-Video signal onto a CRT monitor. Cat 3479-7 $199 Removable SATA Rack Backup your data onto a SATA HD and keep it offsite. Easy to use and install. Cat 6787-7 $139 KVM Switch Control two PCs with one keyboard, monitor, and mouse. Comes with 1.2m cables. Cat 11668-7 $129 NEW! NEW! NEW! Wireless Hotspot Allow users to access the Internet over a secure wireless link. Great for cafes, libraries, conference rooms etc. Cat 11451-7 $1199 Holds up to a 17" LCD screen. Uses standard VESA mounts and can be mounted on a wall or desk. Cat 4666-7 $99 NEW! Omni-directional Barcode Scanner An affordable, vertically mounted small footprint, omni-directional laser scanner which is ideally suited to super market checkouts and the like. Cat 1008085-7 LCD Monitor Arm Perfect for use on a PC or Notebook. Has a 3.5mm and SPDIF connection. Cat 23025-7 $99 12.1" LCD Monitor Great for use in a car, boat, or for POS applications. Runs off 12v or 240v. Cat 4658-7 $969 RS232 to RS485 Convert RS232 to RS485. Runs up to 1200m and works in half or full duplex. Cat IC485S-7 $129 Cordless Mini Keyboard A black 88key keyboard, includes a pointing device. Great for when space is an issue. Cat 8750-7 $179 USB to PS/2 Attach a PS/2 keyboard and mouse to a USB port. Multiple units can be attached to one PC or Notebook. Cat 15094-7 $159 Bluetooth Barcode Scanner A CCD cordless scanner that uses Bluetooth. Comes with Bluetooth dongle. Requires AA batteries (not included) Cat 1008178-7 $799 Wireless LAN Equipment! We’ve got the lot - antennas, cards, pigtails, converters, cables! MicroGram Computers Ph: (02) 4389 8444 FreeFax: 1800 625 777 Vamtest Pty Ltd trading as MicroGram Computers ABN 60 003 062 100, info<at>mgram.com.au 1/14 Bon Mace Close, Berkeley Vale NSW 2261 All prices subject to change without notice. For current pricing visit our website. Pictures are indicative only. See all these products & more on our website...www.mgram.com.au M 2005  3 siliconchip.com.au arch SHORE AD/MGRM0305 Dealer inquiries welcome MAILBAG Prawnlite protection not required A thought came to mind when looking at the schematic of the Prawnlite in the January issue. There is no reverse polarity diode in the power supply line. Fitting one might just keep the smoke inside the components when someone accidentally connects the power leads to the battery “about face” in the dark. Is there another form of reverse polarity protection in the circuit that I’m overlooking? As an aside, my experience with white high-brightness LEDs has been less than favourable. Over time they tend to fade in brightness or just fail completely. They are far less uniform/reliable than single colour equivalents. Brad Sheargold, Collaroy, NSW. Comment: there is no reverse protection diode in the circuit but if the supply is reversed, it is unlikely to do any damage to the components. In fact, we inadvertently reversed the supply during the night-time photo shoot – as you suggested might happen. No damage occurred. Cheap electronics & TVs with digital tuners I have read the Publisher’s Letter and the letter entitled “TVs should have digital tuners”, in the January 2005 issue of SILICON CHIP. Currently, there is legislation in North America requiring new TV sets over a certain size to have an integrated digital TV tuner. If the Australian authorities follow suit, this would certainly promote the awareness of digital TV. Also, I think publishers of TV guides should include indications of programs available in digital widescreen, high definition and those which have multiple camera angles. This would also further promote the availability of digital TV. For the last few years, I have been seeing audio equipment with outrageous power output claims (particularly on eBay). My Pioneer C-2000 valve amplifier/tuner has an RMS power output of 11W, with an 4  Silicon Chip EIA music output of 34W, which is measured to an industry standard. I think all amplifiers should have music output power measured under EIA test procedures. Also, I have begun to notice shifting trends in the composition of equipment dumped in landfill. On occasions, I buy some of it from a junkyard very cheaply and I then carry out a Build Quality Investigation (BQI) on them. Do you think the low cost of such equipment could be a result of unfair trade practices? I think such poor quality equipment could be an environmental problem, because the chemicals used are often not identified, because the manufacturer could not be identified. My 20-year old Thorn TV set (Japanese made) is still working well and it never needed repair. I think such sets are very well-made. Bryce Cherry, via email. Critical comment on the November issue I have a number of questions and comments on things I have spotted in the November 2004 issue. In “Circuit Notebook” on page 81, Tarek Helland made a slight mistake: pin 12 is not +12V; it’s -12V (blue wire -12V, orange wire +12V). Although this has nothing to do with the PS_ON wire on the ATX plug, it might cause a problem if someone used the diagram for another purpose. In “Ask SILICON CHIP” on page 108, in the answer to the letter on the Playmaster 300W amplifier, touching the audio input will cause your body to act as an antenna for 50Hz mains hum. Also, touching an earthed item (RCA socket shield or amplifier case) will reduce this 50Hz voltage induced into the amplifier. On a similar note, if touching the shield (cold side of an amplifier input) causes hum, there is either an open-circuit resistor between signal ground to main ground, or the mains earth wire is disconnected from the amplifier. This has come from my own experience. Also in “Ask SILICON CHIP” on the same page, in the letter on the Micromitter’s faulty filter, the GWFB3 filter pins are wrongly marked; the dot is pin 1 which is the 1nF capacitor, so you have the filter orientated the wrong way around. I discovered this by measuring between pin 2 to pins 1 and 3 with an Ohmmeter. Of course, a capacitor will read open circuit and an inductor nearly a short circuit. Also the circuit of the GWFB3 is in the construction article, so it should not be hard to figure that out. Finally, I have quick question on the 3-Step Charger for deep-cycle 12V batteries. Is there protection if the battery is too cold or even frozen? This is bad for the battery’s life but not necessary fatal as long as the case does not crack. A frozen battery should be left to thaw out before attempting to charge it, so the question is: “is there a low temperature cut out?” If not, it will be a simple matter to add to the code but what temperatures should be used? I buy your magazine every month and I enjoy reading it. The only problem is when I finish reading it I’m after more. Keep up the good work. Danny Rawlins, Portland Vic. Comment: Tarek Heiland did not make the mistake – it was a drawing error on our part. You are right about the induction of hum into the input of amplifiers but we still think that the Pro Series is quite prone to oscillation at around 100MHz, leading to the motor-boating symptoms described. As far as the Micromitter is concerned, our prototype was never fitted siliconchip.com.au with the CFWB3 filter even though we made provision for it. We were not able to source it during the development. Having said that, hindsight says that reversing the in-line 3-pin device could cause the fault – we did not think of it when the answer was prepared. Thanks for the tip. We did not make provision for prevention of charging of frozen batteries and it would not be easy to do so with the specified thermistor. In any case, how many people would attempt to charge a frozen battery and how likely is it to occur in this country? To be frozen, the battery would have be very deeply discharged and extremely cold. We agree that there may be people “out there” who would attempt to do it, in which case they could certainly cause damage to the battery. Glad you like the magazine. Battery refinements for Energy Meter I’ve recently built your Appliance Energy Meter (July & August 2004) from an Altronics kit and have one concern and one suggestion. I’ve included a rechargeable battery and note that the battery runs the full electronics when the mains is disconnected which flattens the battery during storage. I suggest that a switch is required to isolate the battery – to save having to unscrew the lid each time. This is even more important if one is using a primary battery. I’ve also come up with an easier way to secure the battery within its steel clip that saves having any holes in the side of the case. Aside from the two Nylon spacers mounted through the lower PC board at either end of the battery, I’ve added a 15mm Nylon spacer on the end of the centre top screw in the display PC board. Into the end of this spacer I’ve screwed a Nylon M3 bolt, leaving it protruding about 4mm. This just touches the battery when the lid is in place. Much neater! Clive Woodward, Perth WA. Comment: thanks Clive. These are worthwhile improvements. Confusion about instantaneous power The Appliance Energy Meter article siliconchip.com.au in the July 2004 issue has mistakes. Is John Clarke aware of them? The caption for Fig.1 says this is an in-phase example. It’s not; it’s a 90° current lag example. Looks like Figs 1 & 3 need swapping. This really “threw” me. I understand that the required power to drive a purely reactive load is very high but your 90° V/I case says that the power is lower than the 0° and 45° cases. Maybe this is the power dissipated by the load; ie, perfect inductors or capacitors do not dissipate power. However, the power company would have a problem if all loads were purely reactive since the power required is huge. Nice little box he built. Mike Peters, Colorado Springs, Colorado, USA. Comment: the Fig.1 and Fig.3 current and phase diagrams are correct. There is no error. Fig.1 shows both current and voltage in phase. Fig.3 shows the current lagging the voltage by 90°. Instantaneous power (green curve) has the same excursion in all three cases (Fig.1 to Fig.3) but average power is different in each case due to the power factor. The 90° lag example in Fig.3 shows the average power as zero and this is correct. It is true that high power factor loads do cause serious problems to the distribution system but this is not a problem for the consumer. About DVD background music I have just a short note regarding a problem a gentleman wrote in about in the January 2005 issue (page 98). He had problems with the balance between the background music and dialog on DVD films. This may solve his problem. The sound effects and music on the film sound tracks is encoded on the front left and right channels behind the screen, while the dialog is encoded on the centre channel behind the screen. If he hooks up one channel of his stereo amplifier to the centre channel of his DVD player and the other channel of his amplifier to either the left or right channel (or both) outputs of the DVD player, he should then be able to balance the dialog and music with his amplifier balance control. I have not tried this but as a long-time pro- Atmel’s AVR, from JED in Australia JED has designed a range of single board computers and modules as a way of using the AVR without SMT board design The AVR570 module (above) is a way of using an ATmega128 CPU on a user base board without having to lay out the intricate, surface-mounted surrounds of the CPU, and then having to manufacture your board on an SMT robot line. Instead you simply layout a square for four 0.1” spaced socket strips and plug in our pre-tested module. The module has the crystal, resetter, AVR-ISP programming header (and an optional JTAG ICE pad), as well as programming signal switching. For a little extra, we load a DS1305 RTC, crystal and Li battery underneath, which uses SPI and port G. See JED’s www site for a datasheet. AVR573 Single Board Computer This board uses the AVR570 module and adds 20 An./Dig. inputs, 12 FET outs, LCD/ Kbd, 2xRS232, 1xRS485, 1-Wire, power reg. etc. See www.jedmicro.com.au/avr.htm $330 PC-PROM Programmer This programmer plugs into a PC printer port and reads, writes and edits any 28 or 32-pin PROM. Comes with plug-pack, cable and software. Also available is a multi-PROM UV eraser with timer, and a 32/32 PLCC converter. JED Microprocessors Pty Ltd 173 Boronia Rd, Boronia, Victoria, 3155 Ph. 03 9762 3588, Fax 03 9762 5499 www.jedmicro.com.au March 2005  5 Mailbag: continued jectionist, I sometimes have problems with the mix on the soundtracks. Unfortunately, in the cinema we cannot adjust the balance in this manner but it should work in a domestic environment. The result will not be stereo but it should give good wide bandwidth sound for the hard of hearing. With the advent of cheap DVD players with 5.1 decoders built in, this option can be had even if a new DVD player has to be purchased. Graham Johnston, Port Pirie, SA. Radiator fan running after engine turn-off I too have my radiator fan wired to come on at will as does F. W. of Airport West, Vic, “Fan cooling does not work” (page 97, January 2005) and I believe that it is beneficial (especially as the vehicle isn’t young) to help dissipate the heat with the aid of the thermosyphoning effect and the thermostat being open. B. G., Kempsey, NSW. Comment: we have doubts about whether there will be much thermosyphoning in modern cars, with their quite shallow radiators, the tortuous water path through the stationary water pump and hoses and the very high setting of today’s car thermostats. On the other hand, if you can hear the radiator fans running when you are about to turn the engine off, it is probably good practice to wait until they stop running before switching off. Listening to TV channel audio This is to comment on the question and answer on page 97 in “Ask SILICON CHIP”, January 2005. The easiest way to listen to analog TV audio is to get a VHF/UHF scanner with a wideband FM demodulator. I use an Icom IC-Q7A. The TV audio carrier frequencies are in memory. The least expensive way is to get an inexpensive FM radio (almost anything goes) and build a simple pre-converter. That is one dual-gate MOSFET and one crystal oscillator module. The oscillator can be anything 6  Silicon Chip from around 7.5MHz up to 20MHz. Oscillator harmonics cover all TV frequencies. An 8MHz oscillator puts channels 1MHz apart on the FM radio tuning dial but any module from a discarded computer would be OK. Some calculations are needed, so that the converted TV sound would not overlap with a strong local FM station nor other TV sound channel. A simple LC filter is needed to select proper harmonics of the crystal oscillator module. The crystal oscillator module needs 5V but works happily with a 6V battery and two voltage dropping diodes, 1N4148 or similar. For better sensitivity, a one-transistor RF amplifier could be used between the oscillator and the mixer. Common FM radio chips won’t go over 200MHz but it is not too difficult to build the whole receiver using a MOSFET mixer and an FM radio chip (TDA7000) as the IF strip, operating with an intermediate frequency of around 70MHz. Sakari Mattila, VK2XIN, Canberra University, Bruce, ACT. Current transformers can be dangerous Please contact the writer of the letter entitled “Current Transformer for Appliance Measurement” on page 98 of the January 2005 issue, before someone gets killed. For example, a thousand turns on the secondary winding of a current transformer makes a 1000:1 transformer. This can and will generate lethal voltages. Bought devices include a shorting device built into the secondary winding to prevent this. It usually consists of a relatively low-value calibration or shunt resistor. Its value is chosen so that when it is connected in parallel with the meter, the voltage generated by the secondary current gives a correct reading on the meter. Incidentally, passing the wire through the core represents not half a turn but one turn precisely. Certainly that turn goes via the appliance and the transformer outside somewhere. It is still precisely one turn. I have built a current transformer like the one this person seems to require. It was about 25 years ago using an old TV horizontal line transformer. From memory, I used something like 470 turns on the secondary and a 4.7W shunt. The simple maths tells you that this gave 10mV per ampere with a high impedance meter or scope connected to it. One ampere of primary current will produce 1/470 of an ampere of secondary current. 4.7W is the secondary voltage per ampere of secondary current. Thus 4.7/470 = 0.01V/A. Incidentally, the insertion loss is approximately 0.01/470 = 0.0000213 ohms. As you can see, there is no need for an empirical calibration. David Millist, Toowoomba, Qld. Comment: we fail to see how a current transformer can generate lethal voltages unless it has a significant voltage across its primary winding. In a typical current monitoring application, this is not possible because virtually all the voltage is across the load being monitored. That accords with your figure for insertion loss. Nor can we agree that a wire passing through a toroid constitutes a full turn. Considering the magneto-motive force (ampere.turns) generated by the wire, it can only be a half turn, at best. Tsunami warning system via email not workable Your editorial in the February 2005 issue on the recent Tsunami is clearly noble in intent, though I believe flawed in a few points. Specifically, the suggestions on how to warn people of impending disaster – to expect those most affected by such a disaster, those living a subsistence life on the ocean’s edge, to have access to phones of any sort (land-line or mobile), let alone the Internet, is a fallible view. The concept of using the Internet (web, email) is, alas, impossible. As you know, little on the Internet can be trusted and it is all too easy for a vandal or miscreant to impersonate a trusted entity. Basically, if email were an official channel for advising of disasters, guess what every second spam message’s subject line would read? Even for the recent tsunami, a number of low-lifes tried to capitalise via spam or fake “donation” websites (http:// siliconchip.com.au google.com/search?q=tsunami%20 spam%20site). Of course, in a world that has equal access to technology and a secure infrastructure (eg, http://en.wikipedia. org/wiki/S/MIME), it would be a great disaster advisory channel. Ben Low, Perth, WA. Solar hot-water controller P. B. writes from Queensland (page 98, January 2005) asking about a DIY solar HWS. 17 years or so ago I designed and built a controller for the circulator pump on a 450-litre HWS. The controller included a circuit that turns on the pump if the collector temperature approaches zero, as it occasionally does, here in the Adelaide Hills. The HWS has a copper, gravity-feed tank and I made my own collector panels. My installation required the panels to be at the same level as the tank so a pump was required. The pump and controller have been very reliable, not having needed any attention in the 17 years unlike most of the stuff you buy off-the-shelf these days. Keith Gooley, Adelaide, SA. Implantable RFID tags have many drawbacks The editorial on RFID tags in the December 2004 issue got me thinking and I would like to offer my thoughts on the whole idea of chipping. Lest I be considered a Luddite, I should preface my remarks by saying that I work in the IT industry so I appreciate technology. Oh, and I like gadgets. I don’t think that the introduction of implantable RFID chips is the solution it claims to be. Rather, it raises more questions than it answers, the first being: are they really necessary? While they may allow patients to be identified in a hospital, that necessitates some sort of central database which contains a record of every patient to whom a chip has been issued and that every hospital has a connection to that database and permission to view the patient records. Would this be feasible for small country hospitals? What about when you are travelling overseas? Would siliconchip.com.au there be a worldwide database or would each country maintain its own? If a worldwide one, what language would the patient records be stored in? What safeguards would there be to ensure privacy of information? Who would have permission to update the records? How could its security and confidentiality be assured? And so on. I would argue that there already is sufficient technology for identifying patients for treatment in an emergency. For example, patients could elect to have medical information attached to their Medicare number. This is subject to many of the questions I raised above, however it is a system that is already in place. Alternatively, they could carry a card or wear a bracelet, etc which was coded in human readable format (colours, letters, digits, etc) to indicate allergies to drug families. While this would not indicate the full patient history, it would prevent a medical practitioner administering penicillin, for example, to someone who was allergic to it. Also, do we have any statistics on the number of people who are unable to advise doctors of their sensitivities in an emergency? Of these people, do none of them have spouses or family members who could be called on? If the chipping is to be an elective option when one is admitted to hospital, what is wrong with having a bar-coded bracelet instead? This could provide access to the same information that would be available by a chip but would remove the need to be exposed to yet another RF device. And I believe the chips don’t react favourably to NMR/NMI scanners so even in a hospital they could only be used in limited ways. Would it assist identification of people? No more so than existing techniques. Each of us already has a number of unique identifiers, the most obvious being fingerprints. Rather than implant a chip in a newborn baby, why not fingerprint it? This is less invasive, much less painful and just as effective. Sure, the search technology for fingerprints is more processor intensive but it is not an insurmountable problem (and surely its resolution would encourage our different law enforcement bodies to work more closely together). I don’t believe that an implanted chip would prevent or reduce identity fraud, even assuming that a “clean” database of identities could be established and maintained. Most people are basically honest and aren’t out to defraud anyone. Those who are dishonest will always find ways to do so. Let’s consider a few ways in which this can be done. If everyone has a chip implanted, what is to stop another person obtaining an RFID scanner, scanning one or more selected individuals and having chips made with these IDs? The chips do not even have to be the same type as the “official” ones – all they have to do is return the desired code when scanned. These fake chips do not even have to be implanted. There is nothing to stop someone carrying any suitable ID when opening a bank account. I can’t imagine a bank teller requiring a customer to roll up the sleeve of his suit in order to verify that the scan is from an implanted chip – but even then it’s not guaranteed. What happens when the chips fail? The expected life is 20 years, more or less. If identity is determined by a chip, when it fails would a person have access to any of his assets or bank accounts? How would he prove who he was? There is a lot more to discuss but I suspect I’ve used up my quota of words (and I haven’t even touched on the social engineering aspect). I wonder whether perhaps we are becoming too reliant on technology to solve all our problems? Michael Byrne, Morayfield, Qld. AWA Radiola model number The text adjacent to the photo of the Radiola 120 on page 96 of the February 2005 issue refers to the table model companion as a model 120; this should be model 110. Looks like the typing gremlins sneaked in somewhere along the line. Warwick Woods, President, Historical Radio Society of Australia, Inc www.hrsa.asn.au March 2005  7 By Julian Edgar The Revolution in Car Instruments New car instruments no longer use just electromechanical gauges and pointers C ARS HAVE PROGRESSED a long way from the time when a humble eddy-current electromechanical speedo was the only instrument in view. These days, many instrument panels feature LED, LCD and TFT displays – and even conventional-looking dials have stepper-motors driving the needles. Instrument clusters Fig.1: block diagram of a typical current-model instrument cluster. A microcontroller dominates and is used for signal acquisition, filtering, diagnostic functions and for driving warning lights and stepper motors. It also performs the calculations that allow the display of speed, service intervals and oil quantity. [Bosch] 8  Silicon Chip Rather than displaying just fuel level, coolant temperature, speed and engine RPM, instrument panels can now display literally hundreds of discrete parameters. These include trip computer information, GPS navigational information, time, outside temperature, selected radio station, cruise control action, gear position, date, door openings, service intervals, siliconchip.com.au oil level and quality, warning lights and text messages. Fig.1 shows the block diagram of a typical current model instrument cluster. As can be seen, a microcontroller dominates and is used for signal acquisition, filtering, diagnostic functions, and for driving warning lights and stepper motors. It also performs calculations that allow the display of speed, service intervals and oil quantity. At first glance, it would seem that a micro isn’t needed for some of these functions – but think again! Consider, for example, illuminating a low oilpressure light – surely that wouldn’t need to be controlled by a micro? But while the oil-pressure light in modern cars may look to have much the same function as in older cars, some oil-pressure lights are now intelligent in their operation. They monitor the relationship between oil pressure and engine speed, switching on the warning light only when the pressure is lower than it should be for those revs. Service interval indicators, which are used to show when the next service is due, use input data including throttle position, engine RPM and instantaneous fuel economy. From these inputs, a picture of how the car is being driven can be built up – for example, lots of short trips will result in a reduced indicated service interval. Some instrument panels are also being used to perform a hidden function – that of a communications gateway. Because so much information is needed by the instrument panel, it makes sense to position “bridges” between different bus systems (eg, between the engine CAN bus and the body CAN bus) at this location. The stepper motors used to drive needles allow a dramatic reduction in thickness over other electronic approaches. Stepper motor gear ratios of 60:1 and a power of about 100mW allow fast and accurate positioning of needles, with 720 steps available over a 300° needle sweep. Types of display The most common form of advanced display used today is TN-LCD – that is, twisted nematic liquid crystal display. The display can be used over a broad temperature range (typically -40°C to +85°C) and can be configured in either positive or negative contrast forms. Positive contrast means dark siliconchip.com.au The BMW 5 and 6 Series cars use a Head-Up Display system manufactured by Siemens VDO. The information is displayed in a 150 x 75mm field which is located within the driver’s line of sight, in line with the end of the bonnet. The display data is produced by LED light that is reflected across four mirrors positioned behind the instrument cluster. The windscreen is specially modified to reflect the display to the driver’s eyes. [Siemens VDO] characters on a light background, while negative contrast means light characters on a dark background. STN (Super Twisted Nematic) and DSTN (Double-layer STN) LCDs are also being used, with colour provided by the use of LED backlighting. However, TFT (Thin-Film Transistor) LCDs are making rapid inroads into the instrument panel market. TFTs can provide high-resolution colour with video capability. Display monitors that measure 10-18cm (diagonal measurement) are now being widely placed in the centre of dashboards and even larger devices (25-36cm) are expected to be implemented in the form of programmable instrument clusters. The first production car instrument The First Eddy Current Speedometer The eddy current speedometer was invented just over 100 years ago by Otto Schulze. Schulze used a flexible shaft to transmit the rotational speed of the wheel or transmission to the speedometer. Inside the speedo, a permanent magnet was rotated by the shaft and this induced eddy currents in a metal disc or cup located close by, causing it to be rotated against a spring. As the spinning magnet increased in speed, the disc rotated to a greater degree, thereby indicating the speed on the dial via an attached needle. March 2005  9 on Head-Up Displays (HUD). While these have been mooted for years (and one model of Nissan Bluebird was sold in Australia with a HUD projected into the lower corner of the windscreen), advances in technology are likely to lead to more widespread adoption. HUD basics The Mercedes Benz E-Class uses an instrument panel that incorporates many of the new technologies. So that the information display mounted in the middle of the speedo dial is unobstructed, the speedo needle is attached to a revolving ring which is fixed to a magnesium base. The base is gear-activated and driven by a small stepper motor. As a result, the ‘needle’ moves around the perimeter of the speedometer which is illuminated with electroluminescent foils. The central display incorporates both dot-matrix and segment displays. Segments are used around the inner periphery of the speedo to show the speed setting of the Adaptive Cruise Control. The dot matrix display is capable of over 240 warnings in seven languages. A 32-bit micro controls the gauges and displays. [Siemens VDO] cluster incorporating a TFT is the current Audi A8. The 320 x 240 pixel full-colour 125mm screen is located between the speedo and the tachometer and can display information from the on-board computer, navigation system, radio, telephone and adaptive cruise control. The navigation instructions are displayed in a pseudo 3D effect, with perspective, flowing colour changes and moving shadows all used. For the navigation displays alone, 1MB of data has been programmed in, with 35 different scenarios and turn-off instructions composed from over 300 bitmaps. In addition to this navigational information, the TFT screen can show several hundred pictograms and moving animations. Three hundred lines of text can also be displayed – in seven languages! The display is controlled by a dedicated 32-bit processor running 2MB of software. Much work is also being carried out Fig.2 shows the basics of a HUD. It uses an activated display to generate the image, a backlight, an optical imaging system and a “combiner” that reflects the image towards the driver. The windscreen can be used as the combiner. The most common displays used in HUDs are the cathode ray tube (CRT) and the vacuum fluorescent display (VFD), although LEDs can also be used. HUDs tend to display only simple information – eg, speed and navigation. This is to avoid overloading the driver with information that is always within his/her field of view. The advantage of a HUD is that the driver doesn’t need to refocus his/her eyes from infinity to 0.8-1.2 metres in order to read the instruments. This refocusing normally takes up to 0.5 seconds – that’s half a second when the driver cannot see what is happening on the road ahead. The recently released BMW 5 and 6 Series cars use a HUD system manufactured by Siemens VDO. In these cars, important information is displayed in a 150 x 75mm field which is located within the driver’s line of sight, appearing to the driver to be in line with the end of the bonnet. The amount of display data that is shown on the HUD can be configured by the driver or alternatively, the driver can switch it off. The display is produced by LED light that is re- A measure of the internal complexity of the BMW 7-Series instrument panel can be gained in this exploded schematic view. [Siemens VDO] The BMW 7-Series instrument panel uses stepper motor driven needles and back-lit negative liquid crystal displays. Note the navigation information shown on the face of the tachometer. [BMW] 10  Silicon Chip siliconchip.com.au (1) Initially, three conventional-looking round instruments appear on the display – from right to left: tachometer, speedometer and a combination gauge that shows hybrid power status, fuel level and battery voltage. [DaimlerChrysler] (2) The driver can elect – via a pushbutton – to change the instrument display to the one shown here – again from right to left: navigation, speedometer, trip computer (and other things we can’t read in German!). [DaimlerChrysler] Adaptive Instrument Display from Daimler Chrysler The DaimlerChrysler F 500 MIND concept vehicle takes instrument panel displays to the next step. Rather than have fixed instruments, a completely flexible display is used – different instruments can be displayed as the situation requires. (3) Alternatively, at night the driver can bring up the unit’s night-vision system, which uses infrared lasers integrated into the headlights to illuminate objects up to 150 metres away. [DaimlerChrysler] flected across four mirrors positioned behind the instrument cluster. The windscreen is specially modified to act as the combiner. Instrument lighting It is at night that modern instrument panels look most impressive – their display lighting is second to none in the mass-produced instrumentation world. Originally, instruments were frontlit, either by bulbs positioned in the cowl above and ahead of the instruments, or by edge illumination where light was reflected off individual instrument surrounds. Even relatively siliconchip.com.au The Visteon instrument cluster used in the 2003 Renault Megane features LED backlighting. [Visteon] March 2005  11 Fig.2: the main components of a of a Head-Up Display: (1) virtual image; (2) reflection in windscreen; (3) display generator; (4) optical system; (5) electronic control unit. [Bosch] The first production car instrument cluster incorporating a TFT is the current Audi A8. The 320 x 240 pixel full-colour 5-inch screen is located between the speedo and the tachometer and can display information from the on-board computer, navigation system, radio, telephone and adaptive cruise control. For the navigation displays alone, 1MB of data has been programmed in, with 35 different scenarios and turn-off instructions composed from over 300 bitmaps. In addition to this navigational information, the TFT screen can show several hundred pictograms and moving animations. Three hundred lines of text can also be displayed in seven languages! The display is controlled by a dedicated 32-bit processor running 2MB of software. [Siemens VDO] simple instrument lighting of this sort often used acrylic mouldings that acted as “light-pipes”, channelling illumination around the display. Incandescent filament lamps were universally used, with dimming by a current-reducing rheostat. These days, backlighting is becoming widely adopted. Light bulbs have been replaced by LEDs – their smaller size, lower power consumption, ruggedness and longer life having clear advantages over incandescent bulbs. Sources of illumination also now being widely used in instrument pan- els include electroluminescent film and cold-cathode lamps. Electroluminescent (EL) film features very uniform lighting distribution and is most appropriate for illuminating dial faces and displays. Typically, EL film requires 100V AC at a frequency of 400Hz. Cold Cathode Fluorescent Lights (CCFL) are mainly used for backlighting “black screen” instruments – those that appear black when deactivated. In Australia, Lexus has long used this approach. Because a heavily tinted cover (one source suggests the cover typically has a transmissibility of only 25%) is required, very bright lights are required. LCDs also require intense backlighting if they are to retain adequate contrast in daylight. CCFLs meets these requirements, with an efficacy of 25 lumens/watt – approximately 10 times that of the incandescent lamps used in instrument panels. CCFL lighting requires a power supply of 2kV AC at a frequency of 50-100kHz. Incandescent bulbs have a quoted life (based on a 3% probability of failure) of 4500 hours. However, the other three light sources have a minimum life that would usually equate to the life of the car – 10,000 hours or more. Conclusion As car systems become increasingly sophisticated, new techniques need to be found to communicate that information to the driver. The flexibility of electronic displays means that more and more will be found in car instruSC ment panels. The LED-illuminated instrument panels in the current Honda Accord and Accord Euro models feature 3-stage operation. At first, when the driver opens the door, the instrument panel lights with just the gauge markings, as shown in the photo at left. Then, as the driver inserts the key in the ignition, the display brightens further. Turning the key to start the motor brings up all the panel legends before the display settles down to show just the relevant information. 12  Silicon Chip siliconchip.com.au SILICON CHIP Order Form/Tax Invoice Silicon Chip Publications Pty Ltd ABN 49 003 205 490 www.siliconchip.com.au PRICE GUIDE: SUBSCRIPTIONS YOUR DETAILS (Note: all subscription prices include P&P). (Aust. prices include GST) Your Name________________________________________________________ (PLEASE PRINT) Organisation (if applicable)___________________________________________ Please state month to start. Australia: 1 yr ....................$A83 1 yr + binder .....................$A96.50 NZ (air): 1 yr .....................$A89 Overseas (air): 1 yr ...........$A135 2 yrs .....................$A160 2 yrs + 2 binders ..$A186 2 yrs .....................$A178 2 yrs .....................$A260 Address__________________________________________________________ PRICE GUIDE: OTHER PRODUCTS __________­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­___________________­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­____________________________________ Postcode_____________ Daytime Phone No. ( )_____________________ Email address (if applicable) ___________________________________________ Method of Payment: (all prices include GST on Aust. orders) *SILICON CHIP BACK ISSUES in stock: 10% discount for 10 or more issues or photocopies. Australia: $A8.80 ea (including p&p). Overseas: $A10 each (including p&p by air). *ELECTRONICS AUSTRALIA: project photocopies, limited back issues. 10% discount for 10 or more issues or photocopies. Australia: $A8.80 each (including p&p). Overseas: $A10 ea (including p&p by air). o Cheque/Money Order o Bankcard o Visa Card o Master Card *BINDERS: BUY 5 or more and get them postage free.   (Available in Aust. only): $A12.95 each plus $7 p&p per order. Card No. *ELECTRONICS PROJECTS FOR CARS, VOL.2: Aust. $A14.95; NZ/Asia/Pacific $A18.00 including p&p (air); elsewhere $21.50. (All prices include p&p). Card expiry date: Signature_____________________________ *PERFORMANCE ELECTRONICS FOR CARS: Aust. $A22.50; Overseas $A26.00. (Prices include p&p & GST where applicable). SUBSCRIBERS QUALIFY FOR 10% DISCOUNT ON ALL SILICON CHIP PRODUCTS* * except subscriptions/renewals Qty Item Price Item Description Subscribe to SILICON CHIP on-line at: www.siliconchip.com.au Both printed and on-line versions available Total TO PLACE YOUR ORDER siliconchip.com.au P&P if extra Total Price BUY MOR 10 OR ISSU E BACK ES A 1 0 & G ET DISC % OUN T $A Phone (02) 9979 5644 9am-5pm Mon-Fri Please have your credit card details ready OR Fax this form to (02) 9979 6503 with your credit card details 24 hours 7 days a week OR Mail this form, with your cheque/money order, to: Silicon Chip Publications Pty Ltd, PO Box 139, Collaroy, NSW, March 2005  13 Australia 2097 03-05 Build Your Team A Professional Sports Scorebo 14  Silicon Chip siliconchip.com.au Pt.1: By JIM ROWE oard Here’s a build-it-yourself electronic scoreboard that you can put together for a tiny fraction of what you’d have to pay for a commercial scoreboard. It offers large, easy-to-read displays, a convenient wireless console and modular construction which makes it especially easy for a group of people to build. It’s mainly designed for basketball but can be used for other games as well. C OMMERCIALLY AVAILABLE bas- ketball scoreboards have price tags starting at about $2500 and zooming upwards into the stratosphere if you want features like a wireless control console. That means they’re generally out of the question for amateur and school sports teams with plenty of enthusiasm but almost no budget. If you’re in that position, what would you say to a scoreboard you can build yourself for a fraction of the cost of a commercial model? Not only that but it boasts features like big, bright digits 130mm high and a wireless console that can be up to 50 metres or so from the scoreboard itself. It also offers modular construction, so it can be built up easily by a group of siliconchip.com.au people – as long as they have a modest amount of experience assembling electronic projects and some basic woodworking skills. Sounds like a pretty good project for school technology classes, doesn’t it? Especially if the school has some keen basketballers but very little money to spend on luxury facilities like a scoreboard. As you can see from the features box and the photos, the scoreboard offers most of the features found on the majority of commercial units. It has a 2.5-digit display for each team’s score, able to show scores up to 199. It also has a single digit display for the current game period, able to show 1/2/3/4 or an “E” for extra time. And finally, March 2005  15 16  Silicon Chip siliconchip.com.au Fig.1: the Control Console circuit is based on a PIC16F84A-04 microcontroller and a 2.4GHz transmitter module. The PIC scans the control key switches and generates the corresponding command codes which are then transmitted to a receiver in the Scoreboard. there’s the 4-digit countdown timer display, which shows the remaining time in the current period in minutes and seconds for all except the last minute, when it automatically swings over to showing seconds and tenths of a second. A colon is displayed between the minutes and seconds, while a single “decimal point” appears during the final minute – so it’s always easy to see which mode it’s in. The countdown timer automatically resets at the start of each new game period, when you press the “Start Next Game Period” button on the console. The Period display also changes automatically when this button is pressed. Similarly, the timer stops when you press the “Time Out” button and restarts again (from where it stopped) when you press the “Time In” button. To allow easy updating of the score for each team, the console has separate +3, +2 and +1 buttons for them both. It also provides -1 buttons for both teams, so their scores can be decremented easily in the event of scoring disputes or penalties. How do you reset the Scoreboard for the start of a new game? Simply by pressing the two Reset buttons on the console, at the same time. However, to reduce the risk of anyone doing this accidentally in the middle of a game (which would have disastrous consequences), all that happens the first time you press these buttons is that the console flashes a LED on its own front panel marked “Confirm Reset”. It only sends the actual reset command to the scoreboard if you then respond by again pressing the two buttons. Otherwise the reset command will be ignored. The circuitry for the scoreboard itself is built on five PC boards: four for the various display modules and the remaining board for the controller that runs it all. These boards are all mounted in a timber frame, designed to be hung up on a wall, with a 26-way ribbon cable linking all of the boards and providing the displays with power and display data. The control console circuitry is built on two somewhat smaller PC boards, which are mounted in a compact plastic case. The data link between the console and the scoreboard is via 2.4GHz microwave radio signals. By the way, this Scoreboard project has been developed in conjunction siliconchip.com.au Electronic Scoreboard: Main Features • Four separate displays for Home and Away team scores (0-199), current game period (1-2-3-4-E) and the period countdown timer. • Display digits are all 130mm high and are formed using high-brightness 10mm LEDs (four per digit segment). The team score displays are in green, the current period in orange and the timer displays in red for easy reading. • The period countdown timer display shows minutes and seconds during most of each game period but automatically changes over to seconds and 1/10 seconds during the last minute of play. The end of each game period is also signalled by a brief burst of sound from a piezo siren. • All scoreboard functions are controlled by a small wireless console which can be located at almost any convenient location inside the court. • Console buttons allow easy addition of 3, 2 or 1 points to the score of either team, along with the ability to subtract 1 from either team’s score in the event of penalties and scoring disputes. There • Console features extra buttons to start the next game period, stop the countdown timer (Time Out) or restart it again (Time In) – plus a pair of buttons which must be pressed together to reset the scoreboard for a new game. This last pair of buttons must be pressed together twice, to confirm that you really do want to reset the board (which should prevent you accidentally wiping the scores and timers clean. • Unit can be set up to play according to either NBA, FIBA (International) or NCAA basketball rules. This is done by setting DIP switches inside the console. • Both the scoreboard and the control console operate from 12V DC – eg, from either 12V plug pack supplies or 12V batteries. There are no dangerous voltages anywhere inside. This also means they can be used in areas where there is no mains power. with Jaycar Electronics, which holds the design copyright for both its hardware and firmware. As a result, kits for the project will only be available from Jaycar stores. OK, so that’s a quick rundown on what the new scoreboard does and how it’s used. Now let’s look at how it works. Console operation Like the scoreboard itself, the control console is based on a preprogrammed low-cost PIC16F84A microcontroller – see Fig.1. In the case of the console, the PIC operates at a clock frequency of 4MHz, giving a machine cycle of 1ms. The main functions performed by the PIC in the console are scanning the control key switches and generating the corresponding command codes for the scoreboard. As you can see from the circuit, the keys are connected in a matrix configuration to seven of the PIC’s Port B I/O pins, with the three main rows connected to pins RB5-RB7 (configured as outputs) and the four columns connected to pins RB0-RB3 (configured as inputs). The scoreboard command codes generated by the PIC in response to the various buttons being pressed are fed out via Port A I/O pin RA0, configured here as an output. The two Reset buttons are connected in series so that both must be pressed simultaneously, in order to link RB7 and RB0. When this event is sensed by the PIC, it first places a logic high on I/O pin RA4, also configured here as an output. This turns on transistor Q7 which then turns on LED2 – the “Confirm Reset” LED. If you subsequently press the two Reset buttons again, the PIC turns off Q7 and LED2, generates the scoreboard reset command code and sends it out via pin RA0. If, on the other hand, you’ve made a mistake in pressing the Reset buttons and don’t press them again – but press some other button instead – the PIC merely turns off Q7 and LED2 and sends the command March 2005  17 18  Silicon Chip siliconchip.com.au Fig.2: the coded signals from the transmitter are picked up by the receiver in the Scoreboard Controller, decoded and fed to the RB0 input of PIC microcontroller IC1 (PIC16F84A-20P). The microcontroller then sequentially drives the displays via IC2, IC3 and power Mosfets Q2-Q8. code corresponding to the newly pressed button. Another function performed by the PIC is checking the DIP switches (S2) used to set which basketball code you want the scoreboard to use: FIBA, NBA or NCAA. As you can see, the DIP switches are connected to I/O pins RA1-RA3, configured as inputs. All three pins are also connected to ground via 10kW pulldown resistors, so that only the pin corresponding to the switch that is “on” will be taken to logic high level (+5V). Note that the PIC is programmed to check the status of the S2 DIP switches only when it first powers up. That’s because the DIP switches are inside the console and can’t be changed without turning it off and opening the case (changing the rules is not something you’d want to do during a game, anyway). So these switches are only scanned during the console’s power-up sequence and the appropriate control code sent to the scoreboard then. The rest of the console circuitry is used to process the control codes generated by the PIC and sent out via pin RA0, so they can be transmitted to the scoreboard via the AWM609TX data transmitter module. This operates on one of four frequency channels in the range 2.40 - 2.483GHz, as selected by the four DIP switches marked S1. The AWM609TX module and its matching AWM608RX receiver module (as used in the scoreboard itself) were originally designed for transmitting video and stereo audio signals, using frequency modulation and demodulation for both the video and audio. We use all three signal channels here to transmit our digital scoreboard control codes by using the circuitry around IC2, IC3 and transistors Q1-Q4 to pre-encode the digital codes into audio tones, using a simple synchronous phase-shift keying (SPSK) system. This works as follows. First, clock oscillator IC2b generates a continuous square wave clock signal of approximately 10kHz. This is then fed to flipflop IC3b, which toggles back and forth to produce two 5kHz square wave signals at its Q and Q-bar outputs – locked in phase but of opposite polarity. Then one of these 5kHz signals is fed to the clock input of flipflop IC3a, which produces a locked 2.5kHz signal at its Q output. siliconchip.com.au Here is a sneak preview of the main PC board inside the Control Console. The assembly details will be published next month. The 2.5kHz signal from IC3a is then fed through buffer transistors Q1 and Q2, and fed to the video input of the AWM609TX transmitter module. This then sends it to the scoreboard, where it’s used as the clock signal for the SPSK demodulator. On the other hand, the two locked complementary 5kHz signals from IC3b are fed to gates IC2c and IC2a, where they are effectively used to encode the digital control code signals from pin RA0 of IC1. IC2d is used to produce an inverted version of the digital signals and this is fed to IC2c together with one 5kHz signal. The uninverted digital signals are fed to IC2a, along with the other 5kHz signal. As a result, when the digital signal from IC1 is high (1), the 5kHz signal from pin 8 of IC3 is gated through IC2a. Conversely, when the digital signal is low (0), the opposite polarity 5kHz signal from pin 9 of IC3 is gated through IC2c instead. Since the outputs from IC2a and IC2c are effectively combined via diodes D2 and D3, this means that although a 5kHz square wave signal always appears at the anodes of the two diodes, the signal’s polarity or phase at any instant depends on the digital logic level coming from IC1. In other words, the digital control codes are encoded on this 5kHz square wave signal as SPSK modulation. To ensure reliable transmission of this SPSK signal, we feed it through transistors Q3 and Q4 which act as complementary buffers. This produces two versions of the same 5kHz signal with opposite polarity, which are then fed to the two audio signal inputs of the AWM609TX transmitter module. As a result, we not only make use of all three signal channels of the AWM609TX but also achieve maximum link redundancy and noise rejection. But what’s the purpose of the circuitry around transistors Q5, Q6, diode D4 and LED1? These provide a poweron indicator for the console – but a power indicator with a difference. Because the base of Q5 is fed with the buffered 2.5kHz clock signal from Q1, it therefore switches on and off with this signal. The resulting 2.5kHz signal at its collector is fed to the base of Q6 through a simple rectifier/ clamp circuit using the 220nF capacitor, D4 and the 100kW resistor, so Q6 is only turned on during the positive half-cycles of the 2.5kHz signal. As a result, when LED1 glows, it indicates not only that power is applied to the console circuitry as a whole but also that the 2.5kHz signal from IC3a is present – and hence that oscillator IC2b and flipflop IC3b are working. Scoreboard controller Fig.2 shows the circuit details for the Scoreboard Display Controller. March 2005  19 Fig.3: the Scoreboard Display 1 (or Period) board is driven by the control board and uses 28 10mm yellow LEDs to form a single digit. Once again, all functions are under the control of a PIC16F84A microcontroller, which in this case runs at a clock speed of 10MHz (giving a machine cycle time of 400ns). This PIC responds to the control codes from the console, keeps the 20  Silicon Chip scores for the two teams, runs the countdown timer and looks after displaying all of the information via the display board modules. It also handles the important job of sounding the piezo siren briefly at the end of each game period. The control codes from the console arrive at the controller board via the AWM608RX receiver module. This module can operate on any one of four 2.4GHz channels like the transmitter module, as selected by the Channel Select DIP switches (S1). Naturally, the receiver must be set to work on the same frequency channel as the transmitter module, for correct operation of the data link. All of the scoreboard controller circuitry around transistors Q9-Q11, IC4 and IC5 is used in decoding the output signals from the AWM608RX receiver module, to reconstruct the digital control codes sent from the console. These are then fed to the PIC via its RB0 input pin. The decoding is more or less the reverse of the SPSK encoding procedure used in the console. When the 2.5kHz decoding clock signal emerges from the video output of the receiver module, it is first squared up by passing it through a clamp and buffer circuit using diode D4 and transistor Q11. It’s then passed through gate IC4b, used here as a noninverting buffer. From IC4b, it is then fed to the clock inputs of flipflops IC5b and IC5a and also to the base of transistor Q12 via a 10kW resistor. This causes Q12 to conduct during the positive half cycles of the 2.5kHz signal, drawing current through LED1 and making it glow. This allows LED1 to function as a “Carrier Present” indicator. The two complementary 5kHz signals containing the SPSK information from the console emerge from the stereo audio outputs (Ro and Lo) of the receiver module. They are then fed through clamp and buffer circuits similar to those used for the 2.5kHz signal. In this case, one signal is passed through Q10 and IC4a, while the other passes through Q9 and IC4d. One is then fed to the D (data) input of IC5b, while the other is fed to the corresponding input of IC5a. So the two 5kHz data signals are fed to the data inputs of the flipflops, while the phase-locked 2.5kHz clock signal is fed to their clock inputs. This means that on each low-to-high transition of the 2.5kHz signal, the logic level of the two 5kHz signals will be clocked into the flipflops. And as the two signals are the complement of each other, this means that one flipflop should be driven into the set state (Q output siliconchip.com.au Fig.4: the Scoreboard Display 3 board (for Home/Away scores) uses 67 10mm green LEDs to form two complete 7-segment digits and a leading “1” digit. There are two of these boards, each showing a maximum score of 199. high) when the other is driven into the reset state (Q output low). As a result, they toggle back and forth in complementary fashion, in time with the digital control code information coming from the console. siliconchip.com.au To complete this decoding, we feed the Q-bar output of IC5b and the Q output of IC5a to AND gate IC4c, which therefore provides an output high only when both of these complementary flipflop outputs are high simultane- ously. The output of IC4b therefore delivers a clean reconstruction of the original digital control code sent by the console PIC, with a high level of reliability and noise rejection. This decoded control code signal is made March 2005  21 22  Silicon Chip siliconchip.com.au Fig.5: the Scoreboard Display 4 board carries the LEDs and switching transistors for the countdown timer. It has four 7-segment digits plus a colon and these are made up using 120 10mm red LEDs. Five separate PC boards make up the main display panel: a receiver/controller board, one period display board (yellow LEDs), two score display boards (green LEDs) and one countdown timer board (red LEDs). We show you how to build them next month. available at test point TP1 as well as being fed to the RB0 input of IC1. Inside IC1, the PIC’s firmware program responds to the control codes to perform all of the functions in controlling the scoreboard – updating the team scores, operating the countdown timer and keeping the various displays operating. There are 12 display digits in all: three for each team score display, one for the current period display and five for the countdown timer – although the centre digit of the timer display module is dedicated to displaying only a colon or a decimal point. All of the displays are based on the standard 7-segment digit format but use discrete highoutput LEDs rather than dedicated 7-segment display devices. We do this using four seriesconnected 10mm LEDs in each digit segment, in order to get large 130mm high digits. Display multiplexing The 12 displays are all driven sequentially by the PIC controller in standard multiplexed fashion, with one complete display cycle taking place every 25ms. This means that the displays are refreshed 40 times each siliconchip.com.au second (except for very short breaks when the PIC is processing command codes from the console). To turn on each display digit, the PIC outputs a digit code via pins RA0-RA3. This information is decoded by transistor Q1 and by IC2 & IC3, which then feed a logic high to the appropriate digit display circuit via the corresponding line of 26-way cable connector CON1. At the same time, the PIC makes the current 7-segment display code for that digit available via output pins RB1-RB7. These outputs are used to drive power MOSFETs Q2-Q8, which are the power switches for the display segment control lines of all the displays. So as each display is turned on, the appropriate segments are also switched on to display the correct digit or other character. The only remaining function performed by IC1 is to turn on a piezo siren briefly at the end of each game period. It does this by allowing its RA4 output pin (an open collector output) to be pulled high by the 10kW resistor, for three seconds at the end of each game period. This logic high is used to turn on power MOSFET Q13, which in turn switches on a piezo alarm connected to CON3. All the scoreboard controller’s circuitry operates from +5V, derived from the +12V input by regulator REG1. Although the PIC micro and the rest of the CMOS circuitry draw very little current, the AWM608RX data receiver draws over 200mA – bringing the total drain from the +5V rail to nearly 250mA. To allow the regulator to cope with this, diodes D2 and D3 are used to reduce its input voltage, while the regulator is also fitted with a heatsink to help it dissipate the remaining 1.5W of power without overheating. The display modules As mentioned earlier, all the scoreboard displays are on separate boards, which connect to the controller board in daisy chain fashion via a 26-way ribbon cable. This connects to CON1 on the controller board and delivers +12V to the display boards, along with their digit and segment drive signals. All the displays use the same basic circuitry, the operation of which can be understood quite easily by looking at the circuit for the single digit “Period” display (Scoreboard Display 1) – see Fig.3. The digit drive signal from the conMarch 2005  23 Par t s Lis t – Sports Scoreboard 1 900 x 600mm sheet of 12mm plywood 2 900mm lengths of 30 x 15mm DAR maple wood 2 570mm lengths of 30 x 15mm DAR maple wood 5 26-way IDC line sockets (Jaycar PS-0987) 1 piezo alarm, 12V (Jaycar LA5256) 1 1600mm length of 26-way IDC ribbon cable 2 16-way IDC line sockets (Jaycar PS-0985) 1 70mm length of 16-way IDC ribbon cable 1 12V 1A DC plugpack (Jaycar MP-3137) 1 12V 300mA DC plugpack (Jaycar MP-3011) 2 31mm lengths of 1mm diameter brass wire Woodworking glue, 25mm long 1.5mm diameter nails, etc. Main Controller Board (x1) 1 PC board, code BSBCONTR, 127 x 190mm 1 Airwave AWM608RX 2.4GHz receiver module (Jaycar QC-3592) 1 TO-220 heatsink, 6021 type 30 x 25 x 13mm (Jaycar HH-8504) 1 4-way DIP switch (S1) 1 10MHz crystal (X1) 1 PC-mount 26-way DIL socket (CON1) 1 PC-mount 2.5mm concentric DC socket (CON2) 1 2-way PC-mount terminal block (CON3) 4 25mm x M3 tapped metal spacers 13 6mm x M3 machine screws, round head 4 15mm x M3 machine screws, csk head 9 M3 nuts and star lockwashers Semiconductors 1 PIC16F84A-20P microcontroller programmed with SCORDISP. HEX (IC1) 2 4028B CMOS decoders (IC2,IC3) 1 74HC08 quad AND gate (IC4) 1 74HC74 dual D-type flipflop (IC5) 4 PN100 NPN transistors (Q1,Q9, Q10,Q12) 24  Silicon Chip 8 MTP3055 power MOSFETs (Q2Q8,Q13) 1 PN200 PNP transistor (Q11) 1 7805 +5V regulator (REG1) 1 5mm red LED (LED1) 3 1N4004 1A diode (D1-D3) 3 1N4148 signal diode (D4-D7) Capacitors 1 2200mF 16V RB electrolytic 1 100mF 16V RB electrolytic 1 10mF 16V tantalum 3 4.7mF 16V tantalum 5 100nF multilayer monolithic 1 100nF MKT metallised polyester 2 33pF NPO disc ceramic Resistors (0.25W 1%) 1 100kW 1 4.7kW 2 47kW 1 470W 1 22kW 8 47W 6 10kW 7 10W Period Display Board (x1) 1 PC board, code BSB-D1, 102 x 190mm 1 PC-mount 26-way DIL socket (CON1) 4 25mm x M3 tapped metal spacers 5 6mm x M3 machine screws, round head 4 15mm x M3 machine screws, csk head 1 M3 nut & star lockwasher Semiconductors 1 PN100 NPN transistor (Q1) 1 BD136 PNP transistor (Q2) 28 yellow 10mm LEDs, high brightness or standard Capacitors 1 1000mF 16V RB electrolytic Resistors (0.25W 1%) 2 4.7kW 1 120W Team Score Display Boards (x2) 1 PC board, code BSB-D3, 218 x 190mm 1 PC-mount 26-way DIL socket (CON1) 6 25mm x M3 tappers metal spacers 9 6mm x M3 machine screws, round head 6 15mm x M3 machine screws, csk head 3 M3 nuts & star lockwashers Semiconductors 3 PN100 NPN transistors (Q1,Q2,Q3) 3 BD136 PNP transistors (Q4,Q5,Q6) 67 green 10mm LEDs, high brightness or standard Capacitors 1 1000mF 16V RB electrolytic Resistors (0.25W 1%) 6 4.7kW 1 22W 3 120W Timer Display Board (x1) 1 PC board, code BSB-D4, 380 x 190mm 1 PC-mount 26-way DIL socket (CON1) 6 25mm x M3 tapped metal spacers 11 6mm x M3 machine screws, round head 6 15mm x M3 machine screws, csk head 5 M3 nuts & star lockwashers Semiconductors 5 PN100 NPN transistors (Q1-Q5) 5 BD136 PNP transistors (Q6-Q10) 120 red 10mm LEDs, highbrightness or standard Capacitors 2 1000mF 16V RB electrolytic 1 4.7nF 50V greencap Resistors (0.25W 1%) 10 4.7kW 5 120W Control Console 1 console case, 189 x 134 x 32/55mm (Jaycar HB-6094) 1 PC board, code BSBKYBD1, 178 x 111mm 1 PC board, code BSBKYBD2, 163 x 100mm 1 Airwave AWM609TX 2.4GHz transmitter module (Jaycar QC3590) 1 TO-220 heatsink, 6073B type 19 x 19 x 9.5mm (Jaycar HH-8502) 2 4-way DIP switch (S1, S2) 1 4MHz crystal (X1) siliconchip.com.au 13 PC-mount pushbutton switches, 17.5mm square (2 x red, 2 x yellow, 2 x black, 2 x grey, 3 x white, 1 x green and 1 x blue keytops) 1 2.5mm concentric DC socket (CON1) 1 16-way DIL socket, vertical PCmount (CON2) 1 16-way DIL socket, 90 PC-mount (CON3) 9 4g x 9mm self-tapping screws Semiconductors 1 PIC16F84A-04 microcontroller programmed with SCORKYBD. HEX firmware (IC1) 1 74HC132 quad Schmitt NAND gate (IC2) 1 74HC74 dual D-type flipflop (IC3) 5 PN100 NPN transistors (Q2, Q4-Q7) 2 PN200 PNP transistors (Q1,Q3) 1 7805 +5V regulator (REG1) 1 1N4004 1A diode (D1) 3 1N4148 signal diodes (D2-D4) 1 5mm green LED (LED1) 1 5mm red LED (LED2) Capacitors 1 2200mF 16V RB electrolytic 1 100mF 16V RB electrolytic 1 47mF 16V RB electrolytic 2 470nF MKT metallised polyester 1 220nF MKT metallised polyester 4 100nF multilayer monolithic 1 10nF MKT metallised polyester 2 33pF NPO ceramic Resistors (0.25W 1%) 2 100kW 1 2.2kW 2 22kW 1 470W 15 10kW 1 390W 1 6.8kW 1 180W 4 4.7kW Where To Buy A Kit Jaycar Electronics has sponsored the development of this project and they own the design copyright. A full kit of parts will be available from Jaycar in due course – Cat. KC5408. This kit includes a pre-built wooden display frame with screenprinted lettering and individual Perspex covers for the displays; screen-printed and solder-masked PC boards; all on-board parts; and a control console case with a prepunched front panel and screened lettering. siliconchip.com.au Basketball Rules: The Main Differences RULE Duration of Game Extra Time Duration Timeouts Shot Clock Game Clock Stops After Successful Field Goal FIBA NBA NCAA 4 x 10 min periods 4 x 12 min periods 2 x 20 min halves 5 minutes 5 minutes 5 minutes 1 x 60 sec in each of 6 x 60 sec, 1 x 20 sec 4 x 75 sec, 2 x 30 sec the first 3 periods; 2 x per half per game 60 sec in 4th period 24 seconds 24 seconds 35 seconds Last 2 minutes Last 2 minutes Last minute of 2nd of 4th period & of 4th period & half & last minute extra time extra time of extra time troller board arrives via the appropriate pin on cable connector CON1 – in this case, pin 3. It’s then fed to the base of NPN transistor Q1 via a 4.7kW series resistor, so that Q1 is turned on when the controller takes that digit drive line high. When Q1 turns on, this conducts base current for PNP transistor Q2, which immediately switches on as well. This connects the +12V supply line to the anode ends of all seven display segments, so they’re all potentially able to conduct current and light up. Of course, which segments do actually draw current and light up depends on what happens at their cathode ends, which are each connected to one of the seven segment-drive lines in the 26-way cable, accessible via CON1. So if the controller PIC has turned on only segment control switches Q8, Q6 and Q3, only these three lines will be connected to earth during this digit’s display time and only segments “c”, “b” and “a” will conduct current and light up, to display a “7”. Fig.4 shows the circuit of the Scoreboard Display 3 board. It uses the same basic arrangement for each of its three (strictly 2.5) digits. In fact, the circuit for the two full digits is identical to the Period display, apart from the way their digit drive lines are driven from different pins on CON1 (more about this in a moment). The circuit for the leading “1” digit on this board is very similar too, the main difference being that this display digit is only provided with three segments – ie, segments “b” and “c”, plus three more LEDs which are used to fill in the gaps. These are connected to segment line “d”, via a series 22W resistor to match their current to that of the other segments. Note that each of the three digit drive circuits for this board can be connected to either of two lines on CON1. This is because two versions of the board are used in the Scoreboard, one for the Home team score and the other for the Away team score. So the board used for the Home team display has Q3 driven from pin 4 on CON1, making that digit become D2. Similarly Q2 is driven from pin 6 on CON1 and Q1 from pin 8, so these digits become D3 and D4 respectively. On the other hand, the board used for the Away team score display has Q3, Q2 and Q1 driven from pins 10, 12 and 14 on CON1, so the three digits become D5, D6 and D7. The circuit for Scoreboard Display 4 (the Countdown timer display board), is again very similar – see Fig.5. In fact, the four full digits are wired up in exactly the same manner as the Period display. The only one that’s a little different is the centre “digit” D10, which is used only to display a colon or a decimal point. It only has two sets of four LEDs (one set for each dot) connected, as if they are segments “b” and “c” of that digit. We display a colon by turning on both segments, while turning on segment “c” only produces a decimal point. There is only one other small difference in the circuit for the Countdown timer display, involving the addition of a 4.7nF capacitor between the base and emitter of Q1. This capacitor forms a low-pass filter with the 4.7kW series resistor, filtering out a small amount of multiplexing hash which tends to appear on this digit drive line of the cable. Without this capacitor, digit D12 can glow weakly when it’s not supposed to be glowing at all. Next month That’s all we have space for this month. Next month, we’ll move on to building each of the various modules which make up the Scoreboard. SC March 2005  25 SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: dicksmith.com.au A nostalgic look Colour TV in Aus Although a sizeable proportion of readers will have never known anything else, it’s incredible to think that March 1st, 2005 marks the 30th anniversary of the commencement of full-time colour television broadcasting in Australia. What is even more remarkable is the number of colour sets that were there for particular milestone and are still working, in many cases still with superb picture quality! I personally have a 5-set “working museum” of 30-year old sets “billeted” at various relatives’ houses, still in everyday use. And I’d have more if I had the room… In the early 70s, we were piously informed that the maximum working life of a colour picture tube was “about seven years”! In many ways the advent of Colour TV in Australia is a bit like the Second World War: for people like myself, born after 1945, WWII is an event that has always “been there” – but mainly in the sense of the lingering effect it has had on people who lived through that time. Just as there are still plenty of people alive who can remember a dramatically different time before there had ever been a Second World War, there 32  Silicon Chip are plenty of older electronics technicians who remember what it was like when there were no colour TV sets! As with WWII, a staggering number of things changed beyond recognition in just a few short years and there were many casualties left by the wayside. I’ve watched the average 67cm colour TV that needed two people to lift it, had just a mechanical channel selector (usually VHF-only) and no remote controls, evolve into today’s comparatively feather-light equivalent with a window-flat, absolutely rectangular screen, full remote control and multiple video inputs. The average 1974 product cost by Keith Walters around ten weeks of the average worker’s net wages; you can typically pick up today’s version for 3 days net wages . . . or even less if you opt for an old-fashioned curved screen! And people may baulk at the price of today’s Plasma sets but in real terms they work out considerably cheaper than the first colour sets. Right place, right time I started my electronics career in early 1972 at the Brisbane branch of a well-known nation-wide TV service company, so I was right there at the transition to colour. In those days, many electronics enthusiasts my age were keen to make some kind of career in electronics, often for no other reason than working for some sort of “official” organisation siliconchip.com.au k at the start of stralia was about the only practical means of getting any regular access to the electronics “real world”. You have to understand that this was long before the advent of nationwide Dick Smith and Jaycar type specialist electronics supermarkets. Things may have been easier in Sydney and Melbourne but for the rest of Australia, obtaining parts for magazine projects was an expensive and often frustrating business. Electronic component sales were often seen as a relatively unimportant sideline for electrical wholesalers. Buying even fairly run-of-the-mill (by today’s standards) semiconductors often entailed long trips out to obscure industrial estates on the other side of town! I was certainly in the right place at the right time, as the early seventies were an exciting time for electronics in this country and elsewhere. Up until then, apart from the proliferation of “transistor” radios, solidstate circuitry had made relatively little headway in consumer applications. Solid-state technology had certainly been advancing at an incredible pace but most of the activity was in more “serious” fields like the military and computers. siliconchip.com.au Computer manufacturers had started abandoning valves at least 15 years before – out of sheer necessity – but even here the seeds of the future were being sown; in March 1972 the robot space probe Pioneer 10 set out on its history-making mission to Jupiter and beyond. Its on-board computer was based on Intel’s (and the world’s) very first microprocessor, the 4-bit 700kHz 4004, the direct ancestor of today’s multi-GHz Pentium CPUs! The mission was supposed to run for just two years but as it turned out, most of it was still working (computer and vidicon TV camera included) when the probe finally moved out of radio range in 2003! Back on Earth, ICs were becoming steadily cheaper and more plentiful. In Australia in particular, changes in tariff policies were making imported electronic parts cheaper and more accessible, as decades of “stone wall” tariff protection were steadily wound back. Electronics retailing changes A now long-defunct company called Kitsets Australia (remember Kit: “Keep your irons hot, boys . . .”) had just opened the first tiny “Dick-Smith- style” retail outlet in Brisbane. (Dick Smith was operating his first store in Sydney at the time but he didn’t open in Brisbane until quite a bit later). It was quite a big deal to be able to actually see what a magazine project looked like and speak to people who actually knew what we were talking about! And for the first time, parts became a lot easier to get. They even offered mail order for those in the sticks. Servicing changes Those were interesting days in the servicing field too; transistors were finally beginning to catch on with TV manufacturers. Prior to that, apart from portable sets, they had obviously seen little reason to change from the valves that had served them so well for the previous 15 years. “Electronics service” then was pretty much “TV service”. It’s hard to imagine it now but in those days there were no DVD players, no personal computers, no microwave ovens and, apart from portable record players and AM radios, not all that much in the way of sound equipment. If a household boasted any sort of “music system” at all, it was usually March 2005  33 two types of picture tube: the older, wide-necked 90° deflection type with the bakelite base, or the more modern, all-glass, 110° narrow-necked type. If a set had to go to the workshop, it was more usual to simply “pull” the chassis and leave the tube and cabinet behind. Most workbenches were equipped with one of each type of tube on a special stand, a loudspeaker and an audio output transformer combination terminated with crocodile clips and an orientable mirror. An oscilloscope was considered a luxury and it was more often a case of “one per workshop” than “one per tech”! The winds of change My late father’s pride and joy: his 34cm AWA colour portable – probably the reason I started writing this history in the first place! When I bought it for him in 1975 he didn’t expect to be with us much longer and so he kept remarking that the little set would “see him out!” However he got over that illness but true to his word, when he finally passed on 28 years later in September 2003, aged 98, the set was still going, with the picture tube as good as the day we bought it! a radiogram (an AM-only radio, perhaps with shortwave, plus a turntable – itself often capable of playing only 78 RPM records), or if they were really well-off, a “Three-in-One” TV and radiogram combination. FM radio and CDs were still more than a decade in the future and even audio-cassette decks weren’t all that common (reel-to-reel tape recorders were becoming popular). The nearest thing to a mobile phone was a (very expensive) dash-mounted two-way radio! Philips had demonstrated “proof of principle” versions of both home VCRs and videodiscs even back then, but commercial versions were still some years off. The 1960s serviceman A typical field serviceman’s tool kit consisted of a soldering iron (as often as not a “Scope” quick-heating type which could do a great job on guttering but not quite so good on delicate components!), some basic hand tools (side cutters, long-nose pliers and a few screwdrivers), a “20K per volt” analog multimeter, a small selection of plastic ferrite slug twiddling tools and most important, a “quarter inch” nut driver! 34  Silicon Chip A large percentage of the woodencabinet TV sets had their backs fastened on with special screws that could only be removed with this particular tool, presumably to deter idle twiddling by the uninitiated handyman! On my first day on the job I was assigned a vacant bench and amazingly, its previous occupant had cleared its drawer of every item, except for one of these esoteric and hard-to-get tools… I still have it too! The rest of a travelling serviceman’s accoutrement usually consisted of a briefcase full of the more common valves, some 100mF high voltage electrolytic capacitors, a selection of 600V polyester capacitors and usually, the full “E12” range of 1W resistors. There was also usually a small box of odds and ends, germanium and silicon diodes, a few common knobs and so on. The more progressive tech might have carried a CRT “Zapper” (rejuvenator), often home-made and of dubious efficacy! There was a reasonable degree of standardisation in Australian TV set manufacturing, which meant that there weren’t too many different valve types used. There were really only So until about 1970, setting up a TV workshop wasn’t a particularly costly nor involved undertaking but the winds of change were starting to whistle around the door frames. By the end of the decade they would reach hurricane force but we weren’t to know that. It all started in a modest enough way. With the prospect of all-solidstate colour TV receivers on the horizon, some of the manufacturers obviously thought they should get in some “practice” by experimenting with all-transistor large-screen monochrome sets. Actually, since the late ’60s, most manufacturers had been flirting with “hybrid” designs of one sort or another, made from a mixture of valves, transistors and occasionally, even (the then dreaded) ICs! The “grunt” sections (horizontal/ vertical deflection and audio output) were handled by traditional valve circuitry, with transistors (and occasionally, ICs) in the low-power signal processing. It’s interesting to note, though, even when colour TV set sales were well underway, some local manufacturers were still manufacturing and selling all-valve large-screen monochrome sets! From this distance, it’s really hard to see what the point of a lot of this “hybrid” nonsense was. The simple replacing of a valve with a transistor in the low-power signal processing sections had no real cost advantage. And since the bulk of the set’s power was still consumed by the valve audio, vertical and horizontal output stages, there was little or no cost saving in siliconchip.com.au manufacture or electricity consumption either. Apart from this, most valves used were multi-function, most usually a triode and a pentode in the same envelope, so you needed at least two transistors to replace most valves. Maybe the engineers were merely trying to get some solid-state design experience under their belts – but if they were, they were fiddling with the least problematic parts of TV design! This was an even more eccentric approach when you consider the case of European sets which usually didn’t have power transformers. (AWA and Thorn made localised versions of the British Thorn “R” chassis but fitted them with power transformers). In valved signal-processing stages the bulk of the power consumed is simply used by the valves’ heaters. However, since all the heaters in a “transformerless” set were normally connected in series and fed from the 240V mains through a dropping resistor, to maintain the correct heater current in a hybrid set extra resistance had to be added, to substitute for the replaced valves. So practically the same amount of power is used, regardless! (Of course it’s an entirely different story with a colour set, because there’s a lot more signal processing involved). Just about all the major manufacturers produced monochrome portable sets and you’d think, well here at least is a reasonable justification for going for all-solid-state designs. But ironically, two of the most popular “12 inch” portable designs were those made by AWA and General Electric and they were all-valve! At the same time, AWA was making “Hybrid” large-screen sets and all-valve 12 inch portables! (It was also something of an industry joke toward the mid-70s that only remaining manufacturer of valve portables was National/Panasonic, whose slogan went: “Just slightly ahead of our time!”). Of course, if you wanted AC/DC operation, transistors were the only way to go, and although most manufacturers also produced all-solid-state designs, by far the most popular were the HMV models, starting with the infamous “Z1”. Popular? Well, I don’t know if “popular” is siliconchip.com.au Here’s the rear view of the AWA set shown on the opposite page. It only broke down once in 28 years (actually after 22 years) when the damper diode suddenly went short-circuit. And at the time I happened to be staying there, with my tool kit, and with a suitable replacement on hand… Probably just as well, when you look at the way everything was shoe-horned in! the right word but we certainly saw a lot of them. I don’t know what sort of people they had in their design departments either but it appeared that none of them understood anything about RMS dissipation in rectifier circuits, because they all used the same cheap 1A power diodes in a bridge passing about 2.2A! This gave the diodes a life expectancy that could best be described as “toasty, brutish and short”… They also nearly all used the same 11V regulator circuit based on a PNP germanium power transistor. This frequently went short-circuit, often taking out the high voltage germanium horizontal output transistor and/or the selenium EHT rectifier. Then there were the dreaded “green lollies”, a popular type of high-value polyester horizontal yoke coupling capacitor which was forever going short-circuit. All in all, they were certainly a reliable meal ticket for the few technicians willing to put aside their technical insecurities and “have a go”. Kriesler were probably the most serious about large-screen all-transistor sets, with their (in)famous 49-7 chassis. Overall, the 49-7 wasn’t a bad design and I believe there are still a few of them out there! It featured a regulated 35V power supply based on a BDY20 (2N3055) power transistor, a horizontal output stage that used one of the new BU105 1500V silicon power transistors running from a boosted HT line of about 120V, another BDY20 for the vertical output, and a BF177 high-voltage video amplifier stage. Valve jockeys Why “infamous”? Well, all this hightech stuff was good news for brighteyed 19-year-olds like me, raised on a diet of EA/ETI magazine projects, but not so hot for the generation of “valve jockeys” that preceded us. And there were a lot of these somewhat pathetic individuals (often exmilitary with no real theoretical background), who one way or another, had learned to recognise the common faults that plagued old valve TV sets (usually the valves themselves) and could eke out a living armed with a screwdriver and case of spare valves! Most of them eventually learned to recognise other common faults like dried-up electrolytics and leaky paper capacitors. I suppose as long as there was a competent workshop to back them up, they March 2005  35 could usually be relied upon to put in a reasonable day’s field work. The new solid-state techniques changed all that, with the triplewhammy of all-soldered-in, all-solidstate components, mounted on printed circuit boards. Imagine how one of those guys would have felt, the first time he took the back off a sparkling new Kriesler all-solid-state chassis! A new breed of technician was required, able to wield multimeter, oscilloscope and solder sucker with equal facility – and there weren’t too many of those around! (Not for a while, anyway). Well, I guess we should make that a “quadruple-whammy”, what with colour looming on the horizon! When I started, colour TV was still a few years away and so all the sets I encountered were monochrome, many of them dating back to 1959 when TV first started in Brisbane. (A few were even older, having “migrated” up from Sydney!) Incredibly, until at least the early 1990s they still had some of these “originals” under service contract! It seems as long as the customers kept paying the money (and they could get the parts; mostly just valves and other common “generic” items), it wasn’t considered any big deal to make a service call every two years or so! And it’s not all that surprising, really; some of those old sets were incredibly well made; most of them got the chop simply because they were replaced with colour sets! About 15 years ago I helped in the restoration of an original Australianmade 1956 Admiral 21-inch TV. By an extraordinary stroke of luck we managed to locate a working reconditioned picture tube and some of the “oddball” valves that Admiral used. It still works, the printed circuit boards being in perfect condition after nearly 50 years! So in 1972 the vast majority of day-to-day service work consisted of mostly elderly all-valve jobs, with a sprinkling of the “hybrid” types and the occasional all-transistor model. In the case of the older all-valve sets, as with vintage radios, most of the problems were caused by the old style paper capacitors and other passive components. If you have any notions about the new hybrid designs being more reliable, I can assure you, in those there 36  Silicon Chip One of the “newer” Rank Arena sets – basically, a re-badged NEC. Legend has it that a consortium of local manufacturers was offered the choice of the Britishdesigned “true” Rank chassis or a badge-engineered NEC chassis. They took one look at the British effort and took the NEC option! were far more transistor failures than valves. At least with a valve it’s just a matter of plugging in a new one! (Anybody remember those awful black “Anodeon” transistors?) Chroma locked colour TVs Colour TV sets actually began to appear in Australia on a peculiar sort of “grey market” basis in the early 1970s, taking advantage of a technological quirk peculiar to the PAL system. Although there were no official colour broadcasts (and no colour production or playback equipment in the studios), many TV programs sourced from the UK and Europe were supplied on colour videotape. And although they were never designed for it, most of the more recent monochrome studio video recorders could reproduce the colour subcarrier to a certain extent. The Government wasn’t happy about some sections of the community jumping the colour gun, so to speak. So the TV stations were required by law to suppress the colour burst so that any PAL colour sets would only display the pictures in monochrome. But “those in the know” discovered that by the use of an add-on gadget called a “chroma lock” this lack of burst could be overcome (with certain limitations) and quite often, excellent colour fidelity was obtained. Sometimes the chroma lock locked the colours out-of-phase so that all colours were negative of what was expected (the “green face” syndrome often experienced on NTSC pictures those days). A tap of the chroma lock button usually fixed that little problem. AWA imported and sold a few hybrid German Telefunken sets with this facility built in and most technicians with access to colour sets experimented with this technique, often sitting up until the wee hours to watch English Soccer in colour! My first colour TV The first colour TV I ever got to actually lay my hands on was a 26-inch all solid-state “Decca” (actually made by HMV), specially imported from the UK for training purposes in 1973. It was a pretty conservative design, with an SCR-regulated 125V HT line, a 66cm 90° delta-gun picture tube, and mostly discrete components in the signal processing sections. It was a fascinating piece of kit to those of us who’d never set eyes on a colour TV set before but as it turned out, it didn’t have all that much in common with the designs that were siliconchip.com.au eventually manufactured and/or imported here. Fitted with a chroma lock board borrowed from HMV, it did the rounds of a series of beer and prawn evenings held in various technicians’ homes when certain programs known to be in colour were on. The management obviously hoped that curiosity would overcome their abject fear of the Technicolor monster! There usually wasn’t much on during the day. In fact, the first time we saw anything really significant was the 1973 Melbourne Cup. I remember I had the devil of a time dragging the office workers away from the old Pye B&W TV they were crowded around to show them this new marvel. This from a company whose offices were plastered with posters proclaiming their “Engineered for Colour” range of TV antennas! Then we realised that the upcoming live-by-satellite telecast of the wedding of Princess Anne in November 1973 was not only sure to be in colour but also on in the early evening (as it would be morning in London then). Unfortunately a lot of other people realised this too and a few days before the blessed event, HMV wanted their chroma-lock board back! Luckily, I’d already been working on one of my own and I managed to get it ready in time for the big event. But as Murphy would have it, we couldn’t find a single piece of colour material to test it on. “Oh well”, we thought, “we’ll just stay back and see what happens anyway” but around 7pm other people started to arrive. Lots of people – managers and their wives, people carrying cartons of beer and real food! Soon they were everywhere, dragging chairs out of the offices, sitting on boxes, whatever they could find, and eventually the whole loading dock was packed with slavering Royal watchers. Did it work? Yes, thank God, it was actually the best colour broadcast we’d ever seen! State stupidity Of course, no amount of beer and prawns was ever going to substitute for proper technical training but at least it got some of the older guys to actually consider the possibility that they might possibly be of some use when colour came for real! siliconchip.com.au In Queensland at any rate, our quadruple-whammy was really a quintuple-whammy: the state-run technical colleges announced that their colour TV training courses would only be available to people who had undergone official apprenticeships. This probably excluded about twothirds of the Brisbane technical staff, and for that and other reasons, our parent company decided to set up its own in-house training program. A jaundiced view In mid-1972 I was fortunate enough to be struck down with a severe case of hepatitis, requiring a six-week stay in hospital. Why “fortunate”? Well, it worked out rather well for me as I had just bought G.N. Patchett’s excellent textbook: “Colour Television With Particular Reference to the PAL System”. With nothing else to do I applied myself to the subject diligently and came out of hospital something of an expert in the field! We also had the usual assortment of people with “overseas” experience who naturally made out they knew all there was to know about colour TV but when our Decca training set was finally unboxed with an enormous purity error, not one of them seemed to have any idea what to do about this common problem! Yet the procedure given in Patchett’s book couldn’t have been much simpler: “Display a red screen. Loosen the two wing nuts attached to the deflection yoke and slide it backward; this should produce a circular red patch at the centre of the screen. Manipulating the purity magnets as you would picture centring magnets, centre the red spot on the screen, push the yoke back forward until the red fills the screen, and re-tighten the nuts.” Which I did . . . and it worked! Training the untrainable? At this point the management realised that there was a long way to go – they hadn’t even gotten their technicians up to speed on solid-state technology and there was colour TV staring them in the face! It was a very long, arduous and thankless process I can tell you. The only training material available was mostly from the US and the UK and although it covered the basic theory well enough, the descriptions of “typi- cal” colour set designs were years out of date. So we basically had to write our own, using whatever technical information we could scrounge from the local manufacturers and technical colleges. There was also a severe discipline problem, typical of any situation where you’re trying to teach a group of middle-aged people anything! Every time we got a group of technicians together for whatever reason, the discussion would always degenerate into a discourse about how all their problems would be solved if the company simply stopped renewing service contracts on sets more than say, 10 years old. In the end the managers got jack of this and in the first hands-on example I’d ever seen of the awesome power of computer technology, they ordered a special printout of the last three years’ “activity” of a couple of thousand of their service contracts. The printout showed the year of manufacture, the make, and the number of service calls for each of the three years. I can still remember the General Manager laying down the law, too: “Look: There! ‘Year of Manufacture: 1959; Service Calls: 1971 – none!; 1972 – none!; 1973 – none!’ Look at this one: ‘Year of manufacture: 1961’: no calls! Here’s one with just one call! I mean, all these people are paying us $39 year, mostly for doing nothing. Even if we do make a call, how much does that cost us? Half the time you don’t even use any parts, and even if you do, most of them cost next-to nothing!” I don’t recall his closing comments but they were the 1972 equivalent of: “There’s still money in it, guys; deal with it!” If it had been me, I might have also added something to the effect that getting rid of a lot of the old sets would allow them to get rid of a lot of the “dead wood” in the company, whether this was actually true or not… SC NEXT MONTH: In the second part of this feature, we’ll have a closer look at the good, the bad and the downright ugly: the TV sets that ushered in the colour TV era in Australia. March 2005  37 A LAP COUN for Swimming Pools By RICK WALTERS Do you swim laps of the pool to keep in shape? It is a great form of exercise but you’ll know how easy it is to lose count of the number of laps you have done. This PICAXEpowered counter will keep track of the number of laps completed, leaving you to get on with the swimming. 38  Silicon Chip siliconchip.com.au NTER T HOSE FORTUNATE ENOUGH to swim in a 50-metre pool don’t have to count very many laps in order to cover a reasonable distance. For example, just 20 laps means that you have swum a kilometre. But even then, as you plough up and down the pool, it is pretty easy to get distracted and lose count. Some people cope with the problem by swimming five laps freestyle, five breast-stroke, five back-stroke and so on. The problem is worse if you’re swimming in a 25-metre pool (as many top-level swimmers regularly train in) and much worse if you’re swimming in your home pool, which may be only 10 or 15 metres long. For a 10-metre pool, you need to do 100 laps to cover a kilometre. Believe us, trying to keep track of that many laps in a home pool while you swim back and forth is practically impossible. This is where our Pool Lap Counter comes to the rescue. It will display the number of laps you have completed on a 2-digit or 3-digit readout, so you can let your mind wander, do mental arithmetic or compose your new symphony while you swim up and down. The Pool Lap Counter consists of two small plastic boxes. One, the “main” box, contains the Picaxe counter circuit and 2-digit readout, while siliconchip.com.au the other contains a large air-switch pushbutton which connects to the main box via a thin air hose and actuates a microswitch when pressed. This is to avoid an electrical connection (even in a battery-powered, low voltage device) around the very damp(!) chemical-laden pool environment. If you swim more than 99 laps, you will have to add 100 to the count or add the third 7-segment LED display. Two ways of counting The way it works is as follows. You place the air-switch at the far end of the pool (from where you normally start). You then dive in (or gingerly wade in), swim to the other end and push the button, whereupon the display indicates “01”. Congratulations, you have completed one lap. When you swim up and back and press the button again, the display will indicate “03”. In other words, the display increments by two each time the button is pressed. As an alternative, because this Pool Lap Counter uses the intelligence of a Picaxe, you can start and finish your laps at the same end of the pool. In this case, you push the button to start and it displays “00”. You then swim up and back, press the button and it displays “02” and so on, until you are exhausted! Eight AA cells (12V) power the counter. To obtain a reasonable battery life, the 7-segment displays are lit for just five seconds each time the button is pressed. Of course, the counter ICs are powered while ever the unit is switched on but this amounts to only a couple of milliamps. How the circuit works Looking at the circuit of Fig.1, IC2 is a 4553 3-digit counter (normally, we only utilise two digits) with a multiplexed output. IC2 internally selects digit one, two or three and places the BCD data for this digit on outputs Q0Q3. These feed IC3, a 4511 7-segment decoder, which energises the segments of the two digits, corresponding to the BCD code. At the same time, output DS1 or DS2 (pin 2 or pin 1) turns on transistor Q4 or Q5 to power the corresponding LED display. The 10mF capacitor and the 100kW resistor on pin 13 of IC2 reset the count to zero when power is applied. The 1nF capacitor between pins 3 & 4 sets the display multiplexing frequency. All this is fairly straightforward. The tricky bits are carried out by IC1, a Picaxe-08 microcontroller. Among other things, the Picaxe needs to cater for people who place the Lap Counter at their start end or at the far end. As noted above, if you place it at the far March 2005  39 Here’s what it looks like close up. The box at left is merely the lap sensor – hit the switch and it sends a burst of air via the clear hose to the main box, right. This actuates a microswitch which in turn increments the count by two. You can set the count for odds or evens, depending on which end of the pool you mount the unit. The air hose can be quite long. end, the Lap Counter should count to one the first time you touch the button and then increment by two for each subsequent touch. We cover both contingencies by fitting jumper J2 for odd increments and omitting it for even. SK1 is arranged to allow programming of the chip “in circuit”. Jumper J1 has to be removed to do this although with the 47kW base resistor for Q1, it is probably unnecessary. This method means you must remove jumper J1 (thus removing any load from pin 7) before you can reprogram the chip. We also use IC1 to debounce the pushbutton microswitch S1. This achieves two things. First, it stops multiple counts from being recorded because of contact bounce within the microswitch itself. Second, it prevents a miscount if you accidentally push the button twice within five seconds. You could easily do this if you come to the end of a lap, touch the button (or plate or whatever) and then press it again as you push off for another lap. Each time the Picaxe registers the closing of the microswitch, it gener- ates two clock pulses to increment counter IC2. If you look at the Picaxe listing (LAPCOUNT.BAS), you will probably be able to glean what it does but let’s just briefly outline the procedure. Each time you push the button, several things happen. First, IC2 is incremented by two counts (or one count if it is the first time) and then it is disabled, preventing it from registering multiple counts. At the same time, the display is unblanked for five seconds so that you can see the count. Three outputs from IC1 are used to achieve this procedure. Pin 6 disables the counter by going high (for five seconds) to turn on transistor Q2 which then pulls pin 11 (DIS) of IC2 low. Pin 5 of IC1 provides the clock pulses which are inverted by transistor Q3 before being fed to pin 12 (CLK) of IC2. Finally, pin 7 of IC1 unblanks the display by turning on transistor Q1 to pull pin 4 (BL-bar) of IC3 low for five seconds. The three transistors (Q1-Q3) also provide level translation between the 5V signals from IC1 and IC2 & IC3 which run from the full 12V provided by the eight AA cells. Regulator REG1 is fitted to provide the 5V rail for the Picaxe. As noted in previous issues, there is a great deal of confusion over the way the Picaxe ports are numbered, for what they call pin 3 is actually pin 4 on the IC and so on. We have taken the liberty of renaming them in the more conventional manner as P0, P1, P2, etc.We have used the decimal point (pin 8) of the units display as a power indicator to remind you to turn the Lap Counter off. This stays illuminated even when the lap count is blanked. Air-switch S1 is an all-plastic “air-switch” which is normally used in spas and other areas where water and power don’t mix. We got it from our local pool shop, along with a matching microswitch and a metre of 5mm clear plastic connecting tube. The length of tube can be much longer – depending on your requirements, it could be as much as several metres. We use it here mainly because any electrical switch put near a pool with (Left) the air-powered switch we used to actuate the counter. It’s normally used in spas and should be available from most pool shops. (Right): the switch fitted in an open UB3 case. The switch just fits in this case but you might need to perform minor surgery on the ridge inside the lid to make sure it doesn’t foul the switch nut. The length of 5mm plastic air hose can be as long as required. 40  Silicon Chip siliconchip.com.au salt and chlorine would not last very long. When the air-switch button is press­ ed it compresses small bellows which transmit the pressure along the plastic tube to the microswitch mounted in the Lap Counter case. If you don’t wish to go to the added expense of the air-switch, you could use a standard pushbutton in the actuator box and run a piece of light duty figure-8 flex to the Lap Counter case. Construction All the circuitry for the Pool Lap Counter is mounted on a PC board measuring 141 x 83mm and coded 08103051. It has a notch at one end to accommodate the microswitch and chamfers on the four corners. Even though most people will only use two 7-segment displays, we have made provision for a third display (DS3), together with its driving transistor (Q6). If you fit the third display, you will have to install another 10 machined pins for DS3 as well as fitting Q6. We have shown the jumper, which connects IC2 to the base of Q6 Fig.1: the circuit consists of two basic parts – the Picaxe-08 which senses the input from S1 and a display circuit, consisting of IC2, IC3 and giant LED displays. Display DS3 is optional and is only required if you want to count more than 99 laps. Who do you think you are, Grant Hackett? The main box end-on, showing the connection for the air hose to the pushbutton lap counter switch. Here are the giant LED displays we used – they’ve visible for miles kilometres a long way! We’ve turned one upside down so you can see the pin arrangement. Take care: you can get them upside down. siliconchip.com.au March 2005  41 DS2 DS1 CON2 220Ω 220Ω 220Ω 220Ω IC3 4511B 100k Q2 BC549 220Ω 47k 1n 47k 220Ω J2 ODD 100 µF 47k 10k 10 µF 220Ω TO S1 1 1 1 IC2 4553B CON1 + 47k 10k IC1 PIC-08 PROG E ROF TUOTUC 22k POWER CON3 HCTIWSORCIM 10k Q4 Q6 BC327 BC327 DS3 Q3 BC549 47k 100nF REG1 78L05 47k Q1 BC549 1.5k Q5 BC327 Fig.2: the component overlay shows the position of all components. Note that the sockets for the LED displays are mounted on the track side of the PC board. 5002 C 15030180 RETNUOC PAL This is the completed “main box” immediately before the PC board is folded over and mounted upside down on the four tapped pillars. The battery holders are held in place with our highly technical (and patented) battery holder holder. on the overlay so this link will already be in place. The board assembly is reasonably straightforward but as usual, first 42  Silicon Chip check the board for open circuit tracks and etching faults, particularly where the tracks go between IC socket pins. You will most likely have to make the cutout for the air-switch yourself. Use a small hacksaw to make the cuts parallel to the longer board edges then use a large pair of bullnose pliers to break the fibreglass away in small pieces. If you scribe a deep line, you will get a clean break but if it’s a bit ragged, a quick rub with a file will give you a neat edge. The first components to mount are the LED display sockets which mount on the copper (ie, solder) side of the PC board. To get the spacing exact, we use the displays themselves to hold the pins while we “tack” the pins in. Cut the pin strip into four pieces of five pins and carefully align the LED pins with the strips and push them on. Now place the LED sockets on the track side of the PC board – not the component side – in the DS1 and DS2 (units & tens) positions. That done, place the PC board on a flat surface and solder the outside pins on each pin strip on both the top and bottom of the display. There is no need to worry about the display orientation at this stage. Now carefully remove the displays and solder the remaining pins. A pointed tip on your soldering iron will make the job easier but we managed with the usual spade tip and a lot of care. Cut about 2mm off each pin on each display so that it fits flush against the pin strip. Now turn the board over to the component side and fit the seven siliconchip.com.au Fig.3: there’s not much wiring required – most is on the PC board and what’s left uses plugs and sockets for convenience. Power is switched between the batteries simply to make the wiring simpler – this way there are only two wires to go to the PC board. CON2 1 2 3 4 CON3 JUMPER SHUNT S1 PRESSURE SWITCH 4 x AA CELL HOLDER 4 x AA CELL HOLDER S2 POWER links, then the resistors, followed by the IC sockets, jumper, transistors, electrolytics and the three polarised connectors. Make sure you insert the electrolytics with the correct polarity – and note that the 10mF electrolytic must lie flat on the PC board to prevent it fouling the batteries. The 3-pin header must also lie flat on the PC board. As right-angle connectors are rare, put a dob of glue on the flange and use cut-off resistor leads to connect it to the board. Only the outside pins need to be connected. The mating header has pin 1 marked on it when you come to connect wires. Next, fit the mini-shunts to J2 and, if you are using a pre-programmed PIC, to pins 3 & 4 of SK1. Power switch S2 is wired between the two AA battery holders to simplify the wiring. Solder one lead from each battery holder to the switch (one red, one black) and then the other battery wires got to connector PL3: black to pin 3 and red to pin 1. Plug PL3 in. Resistor Colour Codes o o o o o o o siliconchip.com.au No. 1 6 1 3 1 7 Value 100kW 47kW 22kW 10kW 1.5kW 220W 4-Band Code (1%) brown black yellow brown yellow violet orange brown red red orange brown brown black orange brown brown green red brown red red brown brown 5-Band Code (1%) brown black black orange brown yellow violet black red brown red red black red brown brown black black red brown brown green black brown brown red red black black brown March 2005  43 Parts List – Swimming Pool Lap Counter 1 PC board, code 08103051, 141 x 83mm 1 plastic case, 158 x 95 x 53mm; Jaycar UB1 or equivalent 1 plastic case, 130 x 67 x 43mm; Jaycar UB3 or equivalent 2 16-pin IC sockets 1 8-pin IC socket 1 air switch (S1) – see text 1 SPST miniature toggle switch (S2) 2 flat battery holders to suit 4 AA cells; Jaycar PH-9204 or equivalent 8 AA cells 20/32 of IC socket strip; Jaycar PI-6470 or equivalent 1 2-pin strip 0.1-inch spacing (J2) 2 mini-shunts 1 2-pin polarised male connector 1 2-pin header (with pins) 1 3-pin polarised male connector 1 3-pin header (with pins) 1 4-pin polarised male connector (for PIC programmer cable) 4 25mm threaded hex spacers 1 10mm threaded hex spacer 2 3mm x 20mm countersunk head bolts (air switch) 5 3 x 6mm countersunk head bolts 1 3 x 10mm countersunk head bolt 4 3 x 6 mm cheese head bolts 7 3mm nuts 6 3mm star washers 1 65 x 20mm aluminium or fibreglass (battery clamp) Suitable length hookup wire for air switch Semiconductors 1 Picaxe PIC-08 programmed with LAPCOUNT.BAS (IC1) 1 4553 3-digit counter (IC2) 1 4511 BCD to 7-segment decoder (IC3) 3 BC549 NPN transistors (Q1-Q3) 2 BC327 PNP transistors (Q4-Q5) 1 78L05 5V regulator (REG1) 2 70mm 7-segment displays (DS1-2; Jaycar ZD1850 or equivalent) 1 70mm 7-segment display (optional) Capacitors 1 100mF 16V PC-mount electrolytic 1 10mF 50V RB low leakage electrolytic 1 100nF (0.1mF) 50V monolithic ceramic (code 104 or 100n) 1 1nF (.001mF) MKT polyester (code 102 or 1n0) Resistors (0.25W, 1%) 1 100kW 3 10kW 6 47kW 1 1.5kW 1 22kW 7 220W Now fit the batteries, turn the switch on and measure the voltage between pins 16 & 8 on both IC2 & IC3 (the meter’s red test lead goes to pin 16 in each case). It should be slightly more than +12V. Similarly the voltage between 44  Silicon Chip ; PICAXE-08 CODE for LAP COUNTER ; using 4553 and 4511 to drive 2 ZD1850 displays ; ;Define inputs and outputs ; symbol msin = pin4 symbol evenodd = pin3 symbol blankdisp = 0 symbol addcount = 2 symbol odd = 1 ; ;Set output states ; high blankdisp high odd low addcount ; ; wait 3 ;allow IC2 to reset ; init: if evenodd > 0 then initeven ;if jumper missing start at 0 & inc by 2 if msin = 0 then initodd goto init ; ; initodd:low odd ;else jumper fitted, IC2 pin 11 high pause 10 ;hold high for 10 mS high odd ;then take low, 1 clocked into counter goto unblank ;(Q2 inverts logic) ; initeven:if msin = 0 then inccount ;wait for microswitch to close goto initeven ; ; inccount:high addcount ;2 counts must be added to the display pause 10 ;take IC2 pin 12 low for 10mS (Q3 inverts) low addcount ;then high for 2 mS pause 2 ; high addcount ;then low for another 10 mS pause 10 ; low addcount ;then high again goto unblank ;now show the new count ; unblank:low blankdisp ;take IC3 pin 4 high for 5 seconds wait 5 ;(Q1 inverts logic) high blankdisp ;turn display off goto initeven ;wait for next closure of microswitch pins 1 & 8 of IC1 should be within 10% of 5V. Once these voltages are correct, turn off the power, insert the three ICs and if you intend to program your own PIC, do it now. Then fit J1 between pins 3 & 4 of SK1. Turn the power on and after a second, the decimal point on the righthand display should light. So far so good. Run two twisted wires from the microswitch NO and C(ommon) contacts to the 2-pin header (PL2). The polarity is immaterial. Plug it in and after connecting the tubing from the airswitch pushbutton to the microswitch connector, each push of the button should advance the counter by two counts. After five seconds, the count should blank. Note: the count will only advance after the 5-second delay when the display is blank. If everything is operating correctly, you can drill the siliconchip.com.au Left: this view shows the PC board mounted inside the case before the 7-segment LED displays are fitted. Note that the display sockets are fitted to the track side of the PC board. At right is the same shot but with the displays inserted. The decimal point goes to the bottom, as shown here 08103051 holes in the plastic case and fit the four 25mm spacers, first fitting a 3mm nut on each of the countersunk screws. The nut brings the front of the displays flush with the rear of the perspex, thus holding them firmly in place. Mount the air-switch and power switch, fit the batteries into the battery holders and drop them into the case, then sit the PC board on the spacers. Adjust the spacers until the four of them align with the board holes. A Spintite and a little gentle leverage will do the trick. Place the clamp strip on top of the batteries to prevent them moving, then secure the PC board using four cheese-head machine screws and star washers. The front panel cutout may prove a challenge. We obtained a small piece of 3mm neutral tint perspex from a plastics supplier and took it to an engraver who cut it to size with a chamfer on all four sides. We carefully cut the hole in the case lid with the reverse chamfer, thus allowing the perspex to almost sit flush with the lid. A few drops of superglue held it firmly in place. C 2005 LAP COUNTER + CUTOUT FOR siliconchip.com.au MICROSWITCH The pushbutton switch we used is great for keeping water and chemicals away from the “works” but is not particularly convenient as far as the swimmer is concerned. Our swimmer found it a real drag (no pun intended) to have to stop at the end of each lap and press the button. With a little thought, we’re sure you can come up with a much better arrangement. One possibility is to use a reasonably-sized hinged flap which the swimmer merely has to make slight contact with at the end of each lap. Given the mechanical advantage such an arrangement could produce, a small movement of the flap could translate into a very positive movement against the air-switch via a suitable actuator. Such an arrangement could also be used for swimmers making tumble-turns. As long as the flap was anchored securely at the end of the pool, the swimmer’s feet could do all the switching as he/she pushed off at the end of each second lap. Whatever you do, just make sure that it is suitably anchored so that there is no danger of injury to the swimmer. We also mentioned before that you could run a much longer air hose than the length our photos show (merely for a convenient photo!). The pressure system is quite E The lap “sensor” Fig.4: full-size PC board artwork. sensitive, so we assume several metres would not be a problem. That’s it: a lap counter that will keep track for you whether you are swimming for fitness. . . or in training for the Beijing Olympics. SC March 2005  45 BOOK REVIEW By GREG SWAIN Complete reference for Red Hat Linux Red Hat Enterprise Linux & Fedora Edition: The Complete Reference, by Richard L. Peterson. Published 2004. Soft covers, 800+ pages, DVD, 185 x 230mm. ISBN 0-07-223075-4. $89.00. While there’s a wealth of information about Linux in its various guises on the Internet, the information is scattered like confetti. And of course, individual articles are often incomplete, disorganised or out of date. In short, you can waste an awful lot of time trying to track down that vital how-to information for a special Linux project or just to learn how Linux works. This comprehensive reference book fixes that problem, at least as it applies to recent Red Hat Linux Enterprise and Fedora editions. But don’t be put off if Red Hat doesn’t happen to be your favourite Linux flavour – the bulk of the information in this handy volume applies to other Linux flavours as well. This reviewer has long been a fan of Linux for its stability, its massive range of applications and its low cost. Indeed, most applications are open source and can be downloaded from the Internet for free. And no matter which flavour of Linux you buy, a vast range of applications will be included with the operating system on the CD or DVD (unlike Windows, where you have to pay extra). Puzzled already? Just think of Linux as an alternative operating system to Windows (complete with a graphical interface) and you have the basic idea. This book includes detailed information on just about any subject involving Red Hat Linux you care to nominate. It’s divided into seven parts with 38 chapters and it doesn’t make the mistake of assuming that 46  Silicon Chip you’re an experienced user or a guru. Instead, it begins by explaining what Linux is, then describes the installation procedure for Red Hat and Fedora Core Linux. From there, it moves on to describing how the interface works, particularly as it relates to the two main graphical environments, KDE and Gnome. It then gives details on command line basics, system configuration and network set-up. This information includes setting up a small local area network (LAN), setting up a virtual private network (VPN), and making a DSL (digital subscriber line) or wireless connection to an Internet Service Provider. Although it’s also suitable for beginners, most people interested in this book will have at least some knowledge of the capabilities of Linux. Want to set up an FTP server for your business or even for use at home? Chapter 21 shows you how, with detailed descriptions on deploying the alternative VSFTP and ProFTPd FTP server applications. How about a web server? Chapter 22 has that covered. Or maybe you want to set up a DNS server, or a DHCP server, or a file and print server – it’s all there. Or how about a mail server? Chapter 24 has the goods here, with detailed descriptions on deploying the alternative Postfix and Sendmail MTAs (Mail Transfer Agents). But that’s all just the tip of the iceberg. Other sections of this book detail network security, network administration tools, user management, journaling file systems, software and file system management, system and user administration (including configuration files and permissions), hard disk management (eg, creating RAID and LVM volumes) and firewalls. Indeed, Linux is an excellent choice when it comes to creating secure firewalls. It’s also easy to configure for network address translation (NAT) and IP masquerading, so that users on a private network can share an ADSL or cable Internet connection. Chapter 19 has all the details on this. As a matter of interest, many people with broadband Internet access now use a Linux box at home to act as a firewall and to provide access sharing. Once set up, the box is typically left running 24 hours a day. A Linux system also makes a great workstation, whether it be for basic office work, multimedia, email or just browsing the net (and the necessary applications are all included on the CD). As such, there’s lots of information on office and database applications (including OpenOffice, Koffice and SQL database systems), plus descriptions of popular Linux-based web, FTP, email and newsreader clients. These applications, along with the abovementioned server applications, are all automatically installed when you install Linux (or they can be installed later). As mentioned above, the book is logically divided into seven parts, with separate chapters in each part. These parts are: Part 1 – Getting Started; Part 2 – Environments; Part 3 – Applications; Part 4 – Security; siliconchip.com.au Part 5 – Red Hat Servers; Part 6 – System Administration; and Part 7 – Network Administration. The individual chapters are as follows: Chapter 1 – Introduction to Red Hat Linux; Chapter 2 – Installing Red Hat and Fedora Core Linux; Chapter 3 – Interface Basics; Chapter 4 – Red Hat System Configuration; Chapter 6 – Red Hat Network Configuration; Chapter 6 – Gnome; Chapter 7 – The K Desktop Environment (KDE); Chapter 8 – The Shell; Chapter 9 – Shell Configuration; Chapter 10 – Managing Linux Files, Directories and Archives; Chapter 11 – Office and Database Applications; Chapter 12 – Graphics Tools and Multimedia; Chapter 13 – Mail and News Clients; Chapter 14 – Web, FTP and Java Clients; Chapter 15 – Network Tools; Chapter 16 – Security; Chapter 17 – Internet Protocol Security (Ipsec); Chapter 18 – Secure Shell and Kerberos; Chapter 19 – Network Firewalls (Netfilter); Chapter 20 – Server Management; Chapter 21 – FTP Servers; Chapter 22 – Web Servers (Apache); Chapter 23 – Proxy Servers (Squid); Chapter 24 – Mail Servers (SMTP, POP and IMAP); Chapter 25 – Print Servers; Chapter 26 – News and search servers; Chapter 27 – Basic System Administration; Chapter 28 – Managing Users; Chapter 29 – Software Management; Chapter 30 – File System Management; Chapter 31 – Raid and LVM; Chapter 32 – Devices and Modules; Chapter 33 – Kernel Administration; Chapter 34 – Domain Name System; Chapter 35 – DHCP Server; Chapter 36 – NFS and NIS; Chapter 37 – Samba; Chapter 38 – Administering TCP/ IP Networks; Appendix A – About the DVD-ROM. Finally, the book includes a comprehensive index and comes with a bonus DVD that contains the Red Hat Fedora Core distribution, plus over 1500 applications (and the corresponding source code). In short, this is a book for both novices and advanced users alike. It contains a wealth of information and will prove particularly invaluable to anyone involved in looking after a Linux system or network. It’s available from SILICON CHIP Publications – see advert this issue. (G.S.) siliconchip.com.au Issues Getting Dog-Eared? Keep your copies safe with these handy binders H Heavy board covers with mottled dark green vinyl covering H Each binder holds up to 12 issues REAL VALUE A T $12.95 PLUS P& P H SILICON CHIP logo printed on spine & front cover H 80mm internal width H Buy five and get them postage free! 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. Silicon Chip Publications, PO Box 139, Collaroy 2097 Car Projects, Volume 2 THE PROJECTS: High-Energy Universal Ignition System; High-Energy Multispark CDI System; Programmable Ignition Timing Module; Digital Speed Alarm & Speedometer; Digital Tachometer With LED Display; Digital Voltmeter (12V or 24V); Blocked Filter Alarm; Simple Mixture Display For Fuel-Injected Cars; Motorbike Alarm; Headlight Reminder; Engine Immobiliser Mk.2; Engine Rev Limiter; 4-Channel UHF Remote Control; LED Lighting For Cars;The Booze Buster BreathTester; Little Dynamite Subwoofer; Neon Tube Modulator Mail order prices: Aust: $14.95 (incl. GST & P&P); NZ/Asia Pacific: $18.00 via airmail; Rest of World: $21.50 via airmail Available from SILICON CHIP Or order by phoning (02) 9979 5644 & quoting your credit card number; or fax the details to (02) 9979 6503; or mail your order with cheque or credit card details to Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. March 2005  47 SERVICEMAN'S LOG Knock, knock – but do it quietly! Some customers really can be a pain in the you-know-what. Unfortunately, I need the money and in any case, I’ve become largely immune to their sometimes illogical behaviour. I don’t like house calls in apartment buildings – especially if there are lots of stairs. I didn’t mind once but not now. I guessed that Mrs Machon’s telly sensed this as I climbed up to her unit on the top floor and knocked quietly on the door (in order not 48  Silicon Chip to wake the 2-year old, as per instructions). Well, of course she didn’t hear me until I turned the knocking level up to “waking-child level”, which then woke mum up. She then angrily answered the door, asking “why didn’t you knock quietly like I asked?” I ignored her question and bit my tongue. “And just where is madam’s set?”, I replied rather sarcastically. She had previously told me that her Teac CTM686SR had no sound or picture. In fact, the sound was fine; it was just the picture that had failed. I began by removing the trillion back-cover screws and about three hours later, the back was finally off (I exaggerate just a tiny bit). Quickly connecting a crocodile cliplead between one of the CRT cathodes and ground momentarily flashed a brightly-coloured horizontal line on the screen. Yep, just as I thought – no vertical deflection. Now the universal story with smaller Teacs of this age group (early nineties) is that two electros dry out in the switchmode power supply, causing the voltage to go high. This in turn pops electros right through the set, also taking out a few zener diodes, fusible resistors and possibly the vertical output IC in the process. However, this problem rarely occurs in the 68cm version. Anyway, considering the logistics of the set, the 2-year old and his mother’s disposition, I decided to take just the chassis back to the workshop. It would be much easier to work there, even if I was taking a chance that I could fix everything without testing. Back on the bench, I replaced the TDA3654 (IC401) and capacitors C910 (47mF 50V) and C908 (10mF 100V) with higher voltage EXR types. I then checked all the fusible 0.68W resistors and checked carefully for dry joints and any suspicious-looking electros. Finally, feeling fairly confident that everything was “schmicky mouse”, I phoned to quote and arranged an acceptable time to return the set the next afternoon. Unfortunately, things didn’t look siliconchip.com.au good when I arrived on time, as Mum had decided in her wisdom to pop out for a couple of hours, leaving Grandma in the unit without any money to pay the bill. Rather than waste time, I refitted the chassis and switched the set on, only to find that it was stuck in the standby mode and would not start. However, after flicking the mains switch a few times, it suddenly came on with everything looking perfect. The remote worked and I could operate every function, including switching the set on and off. Annoyingly, mum still hadn’t returned by the time I had finished so I was forced to go and do another job and return later to pick up the money. At least she had the good grace to apologise and I thought no more about it until a fortnight later, just before the Christmas holidays, when she left a message on my answering service complaining that the set had no sound. Unfortunately, I wasn’t quite prepared to take time off from my well-deserved holiday to attend to this problem. After all, I knew that she had a spare set which no doubt the 2-year old could trash in the meantime. When I finally did get back to the Machon’s, I wasted no time in taking the entire set back to the workshop – despite having to carry it all the way down the stairs to the car. And when I tested it, I was mortified to see that the set was intermittently not coming on and that when it did, there was no vertical deflection again. I changed IC401 again, then switched the set on and checked the main HT rail to find it was spot-on at +143V on the separate switchmode power supply board. The low voltage rail was also correct at 18V. However, in standby mode, these two voltages dropped substantially, to just 100V and 12V respectively. Not being familiar with this model (and only having a poor photocopy of the circuit diagram for the CTM 715S), I thought that perhaps the power supply was meant to behave like this in standby mode. However, to be safe, I decided to change all the remaining electros in the power supply but this didn’t help. My next task was to find out why the set wouldn’t always turn on. The +143V relay – which is situated on the power supply board – is controlled by a series of transistors (Q905, Q605 & Q604) and by microprocessor IC601 (pin 41). These are all fed with +5V by regulator IC901 and this rail was also spot on. Despite the low standby voltages, I could switch the set on every time by shorting pin 41 to ground. However, while the voltages would rise to their correct levels, there was no sound or picture. On the other hand, if I flicked the on/off switch (S612), which has two extra momentary switch contacts, the picture and sound would come on perfectly. It seemed to me that the problem had to involve the microprocessor and so I started looking for some sort of protection circuit that might be closing the set down (particularly from the vertical timebase). However, I couldn’t find any such circuit. I was getting nowhere and needed to have a plan to get to the bottom of this. At this stage, a friend of mine who used to be a Teac agent lent me a circuit for the CTM686STR which is the Teletext version of this set. However, I soon found that it had important differences, particularly around the poweron micro switch S612. On the CTM686STR circuit, it wasn’t siliconchip.com.au March 2005  49 Silicon Chip Binders Serviceman’s Log – continued 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 H Buy five and get them postage free! Price: $A12.95 plus $A7 p&p per order. Available only in Aust. 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_______ 50  Silicon Chip connected while on the CTM715S circuit, it fed Q604 which in turn was connected to pin 41 of IC601. On the other hand, in Mrs Machon’s set, Q604 went only to pin 11 of IC03 and seemed only to be a sound muting circuit. There was no connection to the standby/power-on circuits. Well, I then spent a huge amount of time replacing microprocessor IC601, the EEPROM (IC602), the 10MHz clock crystal (X601) and numerous transistors and electros without result. In addition, no-one I knew had any clues and there was no-one else to ask. I was stumped – the damn set had got the better of me. But not all was lost. By sheer good fortune, another Teac came in, a CTM5928. This is a 59cm silver cabinet TV with Teletext but at least the chassis was almost identical to Mrs Machon’s set. So, after repairing a faulty main power switch, I checked the voltages from the power supply both in standby and power-on modes. Interestingly, the voltages in standby mode were higher than in the power-on mode, which was the opposite to the power supply in Mrs Machon’s set. Suitably encouraged, I switched the two power supply boards over and noticed that Mrs Machon’s set not only now came on immediately but that the vertical output IC had failed again. It was also at about this time that the “battery-low” sign started to show on my digital multimeter, which I temporarily ignored. This proved to be very foolish because when this warning shows on this particular meter, it starts giving inaccurate readings. This development put a spanner in the works for quite a while, as I was constantly monitoring the two voltage rails with it, until it dawned on me what was happening. At this stage, I decided to replace the two brand new electros I had fitted in the power supply right at the beginning. And would you believe it, just as I was desoldering C908, one of its pigtails fell out! I have had problems before with these particular electrolytics from my supplier. But, hey, what can you do? If you whinge about it, the only comment you’ll get back is “we have sold x trillion of these and yours is the first that’s caused any problems”. It’s just not worth the phone call but it really was frustrating that a cheap brand-new component had caused so much expensive time wasting. The faulty capacitor had been causing intermittent output voltage levels. In standby mode, the output was too low to operate the relay, while in siliconchip.com.au power-on mode, the output level was too high and destroyed the vertical output IC. A new capacitor fixed all the problems. The Turkish Teac Another Teac, this time a model EU68ST employing a Vestel 11AK19 chassis made in Turkey, also recently came into the workshop. This is an entirely different animal to its Chinese-made forerunners. The set was dead, probably due to a power surge from a storm the night before. I soon found that the MTW8N60E FET was short circuit and this had also taken out R817, a 2.2W 5W resistor. I don’t really understand why this surge resistor – which feeds the bridge rectifier – always fails instead of the mains fuse but it is very common in switchmode power supplies. Because IC802 (MC44604P) is so closely coupled to the FET, I felt it wise to replace that too, in case of a repeat failure (there is no safe way to test it). Anyway, I ordered the parts from Speedy Spares who lived up their name, the parts turning up the very next day all the way from Melbourne! They advised that the FET is Items Covered This Month • • • • • • Teac CTM686SR TV set Teac EU-68ST TV set Philips A10A chassis TV set Sony KV-EH36M31 FD Series Trinitron TV set (AE-5A chassis) LG MT42PZ41V TV set LG RT23LZ40 TV set now replaced by a 2SK2545, TEC part number 30001388. Unfortunately, that wasn’t the end of the story because after replacing all the parts, the set was still dead. As a result, I checked the line output transistor which measured OK, then kept on making DC resistance checks until I found that mains diode D816 (BYM26D or UF5407, part number 30007681) was leaky. Now, I never know what to substitute for these diodes and can’t find any specifications for them. However, I’ve been around long enough do know that “diodes ain’t diodes” and so I ordered the genuine part from Speedy. I replaced it the next day, along with the two ferrite beads on each end, and resoldered the dry joints to resistor R828. The set now fired up, the B+ rail measuring +149V which is correct. I left it to soak test but an hour later, it decided to bite me again. This time there were intermittent pincushion and width problems. After another hour of careful heating and freezing, I finally nailed it down to a dry joint on L602 which feeds the east-west correction circuitry. Bread & butter The Philips A10A chassis is still putting bread on the table with its troublesome SSB board. And although others are game to replace the surfacemounted micros, I’m not – particularly when it comes to warranty claims. I had a case recently when the complaint was the usual intermittent no remote control and then dead, which an exchange SSB board fixed. But then, three weeks later, it started cutting out, giving “error 4” messages on the flashing red LED. This usually indicates no +5V rail or Superbright Lumileds - Indoor & Outdoor LED light fitting range D HIGH BRIGHTNESS D LONG LIFE D FULLY DIMMABLE D ENERGY EFFICIENT The range of LUMILED downlight fittings shown here have been designed for domestic, display, marine, mobile home and caravan applications. All fittings use Lumileds, which are: - Long life (typical 100,000 hours) - High efficiency, low power, low voltage - Vibration proof The OPLLGW series White powder coated. This series is a ceiling type gimballed fitting and require a 57mm diameter cutout (MR11 size). The OPLLBL series Black powder coated. This series is a standalone type for use indoors or outdoors, are fully weatherproof and able to be fully submerged for pond application. The OPLLBR series Solid Brass. This series is a standalone type for use indoors or outdoors, are fully weatherproof and able to be fullysubmerged for pond application. Visit us at: www.prime-electronics.com.au PRIME ELECTRONICS siliconchip.com.au The OPLLFG series Gold outer rim with chrome inner finish. This series is a ceiling type fixed fitting and require a 51mm diameter cutout (MR11 size). The OPLLGC series Brushed Stainless Steel finish. This series is a ceiling type gimballed fitting and require a 57mm diameter cutout (MR11 size). The OPLLGG series Brushed Gold Finish This series is a ceiling type gimballed fitting and require a 57mm diameter cutout (MR11 size). Email us: sales<at>prime-electronics.com.au BRISBANE SHOWROOM 22 Campbell Street Bowen Hills QLD 4006 Telephone: (07) 3252 3762 Facsimile: (07) 3252 5778 SOUTHPORT SHOWROOM 11 Brickworks Cntr, Warehouse Rd Southport QLD 4215 Telephone: (07) 5531 2599 Facsimile: (07) 5571 0543 SYDNEY 185 Parramatta Road Homebush NSW 2140 Telephone: (02) 9704 9000 Facsimile: (02) 9746 1197 March 2005  51 Serviceman’s Log – continued that a 5V protection circuit is active, so I ordered and replaced the 5-pin IC regulator. This didn’t fix the problem but what I did discover was that flexing the main board (LSB) would cause a blue screen before bringing on this fault. Gradually, I found that the problem was more sensitive near the lefthand edge of the board and freezer finally managed to pinpoint the problem to a dry joint on L5262. This is almost under the plastic edge rail and feeds 5V to the SSB. A sick Sony A Sony KV-EH36M31 FD Series Trinitron (AE-5A chassis) was thankfully delivered to my workshop bench. It was supposed to be intermittently dead, which I had hoped would allow me to get it into the Service Mode and 52  Silicon Chip let me read the error code. Unfortunately, I didn’t have the service manual to find out how to do this and the Service Mode couldn’t be accessed by the usual display, 5, vol+, power on. By the time I discovered that you had to press both program “+” and “-” together while turning the power on, the set was permanently dead! With the aid of the service kit for this set (a complete set of boards), I found that the Digital Microprocessor M Board, Part No. A1304230R, had failed. An exchange board from Sony fixed the problem (repairing this to component level was not an option). Three warranty jobs Three state of the art televisions from LG came in under warranty. The first was the largest size plasma set in their range and its problem was a tiny strip of light, one pixel wide, on the righthand side running from the top of the screen to about half way down. Unfortunately it was the display itself that was at fault and so it was beyond economic repair. Writing off a set worth in excess of $20,000 really got me thinking – I reckon I could live with this fault if the price was right. However, that’s something I’ll never know – the set went back to LG and the customer got a new one. The second set was an LG model MT42PZ41V which was dead. Its power supply had failed and R101, a 10W 10W resistor, had melted despite having a thermocouple circuit attached to it that’s supposed to monitor its heat and close the set down. Instead, two FETS – Q503 and Q504 (both 2SK3255) – had also been destroyed. After replacing these parts, the set still wouldn’t start and LG insisted that the power supply be replaced as it was under warranty. The new board then had to be set up so that VA = 45V (RA402), VS = +178V (RV401), VY = -70V (RV403), VS set-up = +220V (RV404), RV201 = 5V and RV202 = 12V. The chopper frequencies are fortunately preset at the factory, so that 12V FMIN = 65kHz, VA = 75kHz and VS = 79kHz. The third set was an LG RT23LZ40, which has a 58cm LCD digital Flatron screen. This had no sound or picture . The back light was OK but there was no screen or OSD (On Screen Display). Removing the back and the shielding, I found that there was 15V going into the 12V “stabiliser” IC (a 5-pin device) but only 1.4V coming out – and it was getting very hot. Replacing the 12V IC regulator fixed this but unfortunately, because it was so close to the screen drive circuitry, it had damaged that as well. Opening the back cover to the screen drive board revealed only surface mounted components. However, there was a square hole with another circuit board marked DC1 in the middle, connected via five legs to each side (DIL). A surface-mounted transistor on this sub-board measured short circuit. The service manual had no circuit diagram for this module and there were no circuit references written on it. Nor was there anything in the parts list. In the end, the whole module had SC to be ordered and replaced. siliconchip.com.au MEGA MARCH SALE Mini Digital Video Camera 199 Laser Pointer with Presentation Control PC interaction! Eliminate timing hassles when giving PC assisted presentations. It has a regular laser pointer as well as a wireless IR transmitter / receiver to control the PgUp / PgDn functions on your computer. Works Cat. ST-3108 over $ .95 15m! 49 Laser Pointer with Variable Display Very versatile! Just twist the end of the barrel to change from a dot, to a line, to an arrow. It allows greater ways of highlighting objects or text when giving presentations, and a Cat. ST-3106 whole lot more. $ .95 29 OGGZ - Colour Morphing Mood Lights Set a romantic atmosphere! These rechargeable wireless lights slowly change from one colour to the next, and have a soft glow for romantic or mystical effects. They are charged on their base, and run for up to 6hrs. 1 Piece Set Cat. GH-1047 Includes 1 OGGZ, charging base, and mains adaptor. 3 Piece Set Cat. GH-1048 Includes 3 OGGZ, charging base, and mains adaptor. 14 17 New Store in Hamilton, New Zealand 90 - 92 Commerce St Franktown, NZ Ph: (07) 846 0177 Opens late March USB 2.0 High Definition Terrestrial TV Tuner for PCs Top quality reception! Watch superior quality digital TV on your PC, with the flexibility of time shifting, real time recording, picture-in-picture, and a whole lot more. It operates in enhanced 16:9 format with software supplied for DVD making and manipulation. See our website for system Cat. XC-4814 .95 requirements. $ 249 KIT OF THE MONTH Micromitter Stereo FM Transmitter Kit Transmit quality audio to your FM stereo! Ref: Silicon Chip December 2002. Connect your iPod™/CD/MP3 player to this Micromitter, and then tune into it on your FM stereo system. It uses a surface mount BH1417F processor to provide a compact and reliable FM transmitter design. It is crystal locked to eliminate frequency drift, and the reproduction is great. Kit supplied with PCB, case, silk Cat. KC-5341 $ .95 screened front panel, and all electronic components. Interactive Plasma Disk Cat. GH-1047 $ .95 34 Cat. GH-1048 $ .95 69 Cooling and entertaining! Each fan features 5 super bright LEDs. When they spin, they display 64 incredible patterns and effects. The blades are made from soft foam, so they are safe for kids. Three types available: Desktop Fan GH-1077 Requires 2 x AA batteries. Car Fan with Suction Base GH-1078 Powered by car’s 12V supply. Gooseneck Fan GH-1079 Requires 4 x C and 4 x AA batteries. Cat. GH-1078 $ .95 Cat. GH-1079 $ .95 24 A great light show! This flat panel plasma disk produces an amazing display of blue light which will respond to your touch, voice or music. It measures 152(dia)mm, Cat. GH-1530 and includes a mains adaptor. $ .95 49 Stadium Supertool Precision Drill / Engraver Set High power!Using a robust 10 watt motor that operates up to 7,500 revolutions per minute, this Stadium Supertool is ideal for drilling, shaping, cleaning, grinding, and erasing. Supplied in a handy carry case with a range of attachments. Cat. TD-2464 $ .95 60Pc Drill Accessories Set Versatile attachments! Suitable for drilling, polishing, engraving, grinding, sanding and cutting. Housed in an 8 compartment mini storage case it includes many parts to get the job done. Cat. TD-2404 $ .95 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 2005 49 Animated Lightshow Fans Cat. GH-1077 $ .95 ? Our new 2005 400+ page Catalogue is available next month! Get it with April Silicon Chip Magazine or at your local store! INTERNET> www.jaycar.com.au 69 Dr Video Kit MkII An even better video stabiliser! Ref: Silicon Chip June ‘04. Movie companies deliberately tamper with the video signal to restrict copying, but this robs you of the true high quality picture your system is capable of and you deserve. Get the picture you paid for and strip out these annoying signals from composite or S-video. Kit includes PCB, case, panels Cat. KC-5390 $ .95 and all electronic components. 30 Min Super Fast AA/AAA Battery Charger 99 March 2005 Fantastic price! New This easy to use camera fits improved model with 32MB in the palm of your hand! internal memory The recorded video can be transferred to a computer for editing, or simply viewed directly on any TV with AV inputs. Supplied with camera bag, cables and software. •3.1 mega pixel software resolution for stills. •1.5" colour LCD screen. •5 layer glass lens. •32MB internal memory SAVE Was $249 •SD/MMC expansion slot $50 Cat. QC-3230 •4x digital zoom $ .00 •Internal microphone and lots more! Need to charge fast? How about half an hour! It charges 2 x AAA or 4 x AA, Ni-MH or Ni-Cd Batteries not batteries. Automatic included switching to trickle charge with a microprocessor keeping an eye on things. An array of safety features are included Cat. MB-3538 $ .95 and mains plugpack is supplied. 79 Corner Mounting Dome Dummy Camera Extremely realistic! The metal, triangular shaped bracket mounts into a corner for the impression of wide angle surveillance. The 70mm dome houses a dummy Cat. LA-5312 camera, so you could replace it with a $ .95 working camera for genuine applications. 29 Dome Dummy Camera with Right Angled Bracket Versatile mounting! This dummy camera is designed to mount onto a vertical wall or panel for high visibility and improved deterrence. The 70mm dome houses a dummy camera, so you could replace it with a working camera for genuine applications. Cat. LA-5311 $ .95 19 Rechargeable 40 Channel UHF Transceiver Deal Great range, great features! Since the outstanding success of our popular DC-1010 transceiver, it only seemed logical to refine the design, adding a few enhancements along the way. It is a lot more compact, measuring just 53(W) x 95(H) x 32(D)mm. It uses a small rechargeable battery pack, and is supplied with a dual charging cradle. You can still of course use AAA batteries as a backup. Four step scrambling is also provided for private communications, making this transceiver just plain fantastic! Supplied with one transceiver and a charging SPECIAL OFFER! cradle. Cat. DC-1025 Buy a DC-1025 pack $ .95 & an Extra Transceiver (DC-1028) for just $129.90 Extra Rechargeable Save $30 Batteries Cat. DC-1029 89 $9.95 19 1 Motorcycle Alarm Stop thieves dead in their tracks! It has an ear piercing 120dB siren, and is triggered by a number of events. Supplied with electronic black box controller 90(W) x 32(H) x 75(D)mm, two slimline key fob remote controls, wiring looms, red flashing LED warning light, and siren. Cat. LA-9020 $ .95 69 Microwave Sensor for Car Alarms Extra security! Microwave sensors send out ultra high frequency sound waves, and detect the reflections. It has an effective range of 3m, sensitivity adjustment, and relay output. CCD Colour Dome Camera with Pan / Tilt Function Versatile monitoring! Few surveillance devices can match the versatility of a pan/tilt camera. Wether you want to concentrate on particular areas, or have a large area to cover, the control is at your fingertips. This camera is integrated into a weatherproof dome housing, suitable for ceiling mounting. Just use the remote control to follow the action. It uses a 1/3" Panasonic Colour CCD Sensor to provide quality 420TV line Cat. QC-3497 resolution $ .00 video. 499 Cat. LA-9030 $ .95 29 2 Channel Video Web Server with Email Alert Remotely monitor your system! IP (Internet Protocol) surveillance has revolutionised the way we monitor and record in many surveillance situations. This web server can be connected to an existing setup, and transmits up to 12fps at 640 x 480 resolution. It has two video inputs and four alarm inputs to email you when one is triggered. Cat. QC-3394 $ .00 399 LED Map Reading Light SAVE $2 Don’t get lost in the dark! Great for map reading in the dark, it features a 300mm adjustable Cat. ST-3059 gooseneck and $ .95 cigarette lighter plug. Was $9.95 7 Car Super Tweeter Bargain Fantastic value! They have a frequency response of 6 to 20kHz and 40WRMS power handling. Cat. CS-2218 $ .00 ea 5 Cat. AS-3190 $ .95 34 Colour Video Doorphone Top quality! The colour camera, and LCD screen give you excellent clarity to the picture. Supplied with all mounting hardware and wiring. Expand the system! Buy an extra colour Cat. QC-3606 receiver QC-3607 with your video $ .00 doorphone for just $199. Save $150! 399 Automotive Battery and Alternator Tester Power Window Closers Let your alarm wind up your windows! This unit interfaces with your car alarm to automatically wind up electric power windows when you arm your alarm. It can be used with positive or negative triggered windows, and of course you do need to have power windows Cat. LR-8851 already fitted. Two models available: $ .95 Two Door Version Cat. LR-8851 Cat. LR-8853 Four Door Version Cat. LR-8853 $ .95 8 49 59 Non-Slip Dashboard Mats Roof Mount 7" Monitor Great versatility! It offers wide viewing angles, image reverse, and more! Was Cat. QM-3752 $399 $ .00 299 2 SAVE $100 Ideal for rear seat viewing! It has integrated dome lights in the console, so you can replace your factory interior light. Was $419 Cat. QM-3751 $ .00 379 SAVE $40 Wireless Colour CMOS Camera with Infrared Illumination SAVE $100 Buy an additional camera 119.00 Cat. QC-3275 for just $ Cat. QC-3274 $ .00 199 SAVE $60 B&W Video Doorphone See who’s at your door before you let them in! The 4" screen lets you see your visitors, and you can talk to them through the handset. Supplied with all mounting hardware and wiring. Expand the system! Buy an extra B&W Receiver QC-3603 with your video doorphone for just $99. Save $80! Simple tester for a simple problem. Don’t get caught with a faulty spark plug. Bright neon illumination indicates spark presence. 19 Cat. QC-3602 $ .00 199 Cat. TS-1530 $ .95 14 Cat. QP-2264 $ .95 5 3 - 28V Wireless Auto Tester Cat. GG-2250 $ .95 5 7” Widescreen TFT LCD Monitors for Cars Standard Mount 7" Monitor 89.00 Cat. QC-3271 for just $ Neon Spark Plug Tester Stay safe on the roads! Incorrect tyre pressures can have adverse affects on handling and stopping distance. Keep check on your tyre pressures easily. 0 to 150PSI range. Cat. GG-2310 $ .95 Great on the dash! They will keep small items in place such as mobile phones or sunglasses. Their uses are endless, and they are washable. Measures 170 x 100mm, supplied as a pair. Buy an additional camera A quality portable iron! Make roadside electrical repairs, or just avoid running mains extension leads when doing automotive work! 2.5m lead with cigarette lighter plug. Digital Tyre Pressure Gauge Or 2 for $8 169 12VDC 60W Soldering Iron Keep an eye on your car battery! This tester will check battery condition, and that your alternator is charging properly. Was $13.50 Cat. QP-2262 SAVE $ .95 $4.55 $80 Covert surveillance made easy! You can monitor the transmitting camera from up to 100m away, complete with audio. The camera can be mains powered using the supplied adaptor, or with a 9V battery. Cat. QC-3270 Ltd qty. .00 Was $249 $ Night vision! The camera features 12 IR LEDs that automatically switch on in low light conditions. The strong metal construction offers durability, and the camera can be mains powered using the supplied adaptor, or with a 9V battery. Ltd qty. Was $299 5 x 8" Horn Speaker Ideal for alarms! This attractive unit in high impact white plastic features a special bracket for maximum flexibility in mounting. Ideal for any outdoor application including marine. 20WRMS power handling with 8 ohm impedance. Mini Wireless CMOS Colour Camera with Audio SAVE Safe and easy voltage detection. When positive voltage is detected, it will buzz, vibrate, and light up. It is safe to use with ECUs, air bags, sensors, and transducers etc. Cat. QP-2212 $ .95 29 See our website for full features & specs SAVE $40 Dash Mount 7" Monitor Retractable! This unit folds down to store into a single DIN space (standard car stereo space) so it will go unnoticed. Cat. QM-3753 Was $ .00 $449 SAVE $50 399 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au 64MB USB 2.0 Flash Disk with Built-In Card Reader Extremely versatile memory device! As well as having 64MB of on-board storage, this flash disk also has a card reader for use with SD, MMC, and Memory Stick (including Pro and Duo). Full speed USB 2.0 data transfer and a Cat. XC-4768 compact 28(W) x 80(H) x 20(D)mm $ .95 package. 64 300k Pixel SurfCam USB Web Camera Video conferencing and more! It uses a 300k pixel colour CMOS sensor with auto exposure and white balance for optimum performance. Software included for creating Cat. QC-3223 greeting cards and $ .00 photo albums. 35 19 World Renowned Media Verbatim media is top quality, with reliability recognised worldwide. High Performance 700MB/ 80Min CD-R Cat. XC-4707 CD-RW Rewritable 700MB 80Min 12X 5Pk Cat. XC-4701 Dual Layer 8.5GB 2.4X DVD+R Cat. XC-4744 Cat. XC-4744 $ .95 EA 11 9 USB Phone Charger / Mini Massager 12 Featuring 1.5" micro speakers, & an internal amplifier, they sound great. It all folds up to a neat 286g package when not in use too. Powered by 4 x AAA batteries. •iPod not included. Was $2.95 $3.59 $3.95 $5.25 $12.95 $24.90 $12.95 89 1 Now $2.45 $2.79 $2.95 $3.95 $9.95 $19.95 $9.95 Save $0.50 $0.80 $1.00 $1.30 $3.00 $5.00 $3.00 Cat. MI-5100 $ .95 44 150W (450W Surge) 12VDC to 230VAC Electrically Isolated Inverter SAVE $31 Cat. MI-5102 $ .95 48 Switchmode Dual Stage Lead-Acid Battery Chargers Suits sealed or unsealed Lead-Acid batteries! These fully automatic chargers use switchmode technology to efficiently charge high capacity batteries. They are housed in a robust metal frame, can be powered from 110 or 240V, feature fan cooling, and include 700mm fly leads with heavy duty battery clips. The two larger models also feature an LED bargraph to indicate charging status. See website for full details & specs. 12V <at> 6A Cat. MB-3610 $ .95 79 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 Cat. XC-5163 $ .95 Great Prices on These Modified Square Wave Inverters MI-5102 Was $79.95 INTERNET> www.jaycar.com.au 12V <at> 12A Cat. MB-3612 $ .95 99 Simple, but effective! This cable connects to two USB A ports, effectively doubling the current available to the peripheral device. It has a USB B plug on the end, and is 1m long. Cat. WC-7750 $ .95 14 2.4GHz Wireless Yagi Antenna Boost your wireless range! This antenna is suitable for a range of 2.4GHz uses, and provides around 8dB of gain. It has an SMA socket for connection. Cat. AR-3272 $ .95 Image Media Player 3 SAVE $15 49 129 Great for short runs! They are only regular Cat 5, but work fine. Blue in colour. Ltd qty. 1m Pk5 YN-8181 1.5m Pk 5 YN-8182 2m Pk 2 YN-8183 3m Pk 2 YN-8184 Cat. YN-8183/4 Was $6 Cat. YN-8181/2 Was $4 $ .50 $ .00 Save Save $2.50 $3 MI-5100 Was $59.95 Save a bundle! By using rechargeable batteries, you not only reduce waste, you save yourself money! Ni-MH capacities now rival alkaline counterparts, so you get long run times from each charge. See our website for battery chargers. Cat SB-2444 SB-1723 SB-1700 SB-1706 SB-2429 SB-2460 SB-2467 No more fading memories! Transfer all of you VHS, Betamax, and camcorder tapes to DVD using your computer’s DVD burner. It includes powerful editing software to add colour and transitional effects, as well as sound tracks if desired. Cat. XC-4809 Supports composite and S-Video $ .00 inputs, and PAL or NTSC sources. 100W (300W Surge) 12VDC to 230VAC Electrically Isolated Inverter Cat. GG-2268 $ .95 Massive portable storage! Instantly add gigabytes of storage to your PC or notebook. You can use any 2.5" IDE HDD, and then plug it into your USB 2.0 port for super fast backup, transfer, and Cat. XC-4678 $ .95 storage. Includes carry pouch, cable, and drivers (only required for Win98). USB Power Booster Cable USB 2.0 DVD Maker Great for small appliances! Suited for low demand devices like battery chargers, incandescent lamps, fax machines etc. See our website for full details. Great Savings on Rechargeable Ni-MH Batteries Type AAA 650mAh AAA 900mAh AA 1650mAh AA 2000mAh C 4500mAh D 9000mAh 9V 200mAh` 19 Save on Panduit Cat 5 Cables Cat. XC-4701 $ .75 PK No flat batteries, no sore muscles! Charge your mobile phone from your USB port, or ease away the stress of the day. It suits Nokia, Siemens, Samsung, and Sony Ericsson phones. Cat. XC-5028 $ .95 Portable iPod / MP3 Player Dock and Speakers Utilise USB power and take the strain off your eyes. A 50mm diameter glass lens provides great magnification while a built in lamp Cat. ST-2809 $ .95 lights your work. 1 Highly efficient cooling! Achieve up to 14°C better cooling by using this air duct to pipe fresh cool air to your CPU. It is flexible and extendable between Also 90 and 300mm suitable for long. Suitable Amplifiers! for 80mm fans. 149 USB Magnifier Lamp Cat. XC-4707 $ .65 EA 2.5" IDE - USB 2.0 Hard Disk Drive Case CPU Ventilation Duct 24V <at> 6A Cat. MB-3614 $ .95 99 Digital slide shows on your TV! Just insert your memory card and plug it into the composite input on your TV! Cat. XC-4857 It also acts as a card reader when $ .00 connected to your PC. SAVE Was $149.00 119 $30 USB Radio and Remote Control Radio on your PC! Receive, play, and record FM radio stations through an ultra-stable phaselocked-loop (PLL) tuning system for superior reception. Includes an IR remote control which can also be used with software such as MS PowerPoint. Cat. XC-4880 $ .95 79 Remote Controlled Mains Switch Remote switching of appliances! This wireless mains system can support up to five outlets, each with their individual On/Off buttons on the remote control. They are rated at a maximum of 1000 Watts, so please check the power consumption of high current devices. Supplied with one remote control, and one mains switch. SAA APPROVED. Extra mains switches Cat. MS-6102 $29.95ea. Cat. MS-6100 $ .95 39 20A Solar Charging Controller with LCD Protect your batteries! This microprocessor controlled unit is capable of handling all of your solar charging requirements. It has an array of features including adjustable charging voltage, automatic dusk-till-dawn on/off, overload protection, and a whole lot more. See our website for full details. Cat. MP-3129 $ .95 169 3 Air Powered Jet Hawk Glider LED Velcro Safety Band Flea Exterminating Pet Comb Launch it like a rocket and watch it soar like a hawk! Pump up the air powered launcher and send your Jet Hawk glider soaring 500 feet (150m) into the wild blue skies! It includes a safety feature to disable launching in horizontal or vertical positions. 610mm wing-span. Be safe, be seen! Use this LED safety band when you are out jogging, walking the dog, on your bike, and more. It consists of four red LEDs in an adjustable 30mm wide Velcro band that can be set to flashing or Cat. ST-3026 steadily on. Battery included. $ .95 Chemical free Flea killing! The comb emits an electronic charge to kill fleas on contact. It is suitable for use on cats and short-haired dogs, and requires 2 x AA batteries. Measures 155(L) x 45(D) x 90(H)mm. Cat. GT-3440 59 $ Remote Controlled Secret Farter The new millennium’s whoopee cushion! Activated by a remote control, it has three realistic fart sounds. Cat. GH-1088 19.95 $ High Resolution 5kg Hanging Scales Ideal for the kitchen or tackle box! The EL backlit LCD display indicates weight with a resolution of 1g and accuracy of +/-2g. They are highly sensitive and suited to a wide range of Cat. QM-7230 applications. $ .95 39 Cat. XC-0195 Great for the car or home! Here is a great way to enjoy movies, music, and picture slide shows on your TV or PC monitor. It accepts many common memory cards so all you need to do is load the files on the card, pop it in and you're away! The IR remote control operates all functions, including great features such as image zoom, image rotate, slide shows, and various other great functions. It supports MPEG4 encoded files in MPG, DAT, and AVI format, and Cat. XC-4865 can also play music $ .00 and image files. See our website for full details. Measures 125(W) x 22(H) x 83(D)mm. Alcohol Breath Tester with LCD Readout Stay safe and under the limit on the roads! This unit is very compact & features an integrated LCD to give you an actual readout of your blood alcohol content.. While providing a good indication of BAC, it should not be relied on for precise results, and you should never drink and drive. 199 Cat. QM-7294 12VDC Electric Blanket Slimline 3 LED Book Light MPEG4 Media Player 19 69.95 $ 29.95 $ Stylish and functional! It acts just like a normal running message display, but is only the size of an ordinary name tag! It can be programmed with a message of up to 50 characters, with adjustable scroll speed. 39.95 A great gag for all occasions. They make a fart sound when tipped upside down. Cat. GH-1080 Great for parties! $ .95 Cat. GH-1202 Electronic Name & Message Badge $ Farting Salt n Pepper Shakers Compact and portable! While providing adequate light for reading, it is soft enough to not disturb your sleeping partner. It measures just 40(W) x 105(L) x 10(D)mm, and Cat. ST-3980 requires two $ .95 CR2450 batteries. 9 Marvin the AutoScan FM Radio Robot A great radio! Touch his head to scan for stations and it will lock on to the first one found. Stands 140mm tall. Cat. AR-1772 Requires 4 x AA $ .95 batteries. 19 PLANNING A TRIP OVER THE EASTER BREAK? Keep warm on long car trips! It is made from 100% Terylene fabric and contains a safe, low voltage electric element that heats the blanket and keep you warm. Measures 1.5m x 1.1m. Heated Travel Mug with Temp Display Cat. GH-1205 49.95 $ 12 / 240V Heated Foot Massager Hard day at work? Give your feet some tender loving care. Slip them into the boot shaped massager & soothe those aching feet. Supplied with a mains and car voltage adaptor, it measures 304(L) x 304(W) x 190(H)mm. Multi-Voltage Car Adaptor Very versatile! It has 7 different voltages between 1.5 and 12V at up to 1.5A. 7 plugs are included for use with many common devices. Suitable for use on 12V or 24V systems. Hot coffee all trip long! Four temperature settings between 29°C and 71°C allow you to set the ideal temperature to Cat. GH-1302 keep your drink at. $ .95 Requires 12VDC. 39 Cat. GH-1755 39.95 $ A must have for every recreational fisherman! It includes a 14 in 1 multi tool, 0 - 6kg scales, and an LED hand torch, all in a convenient Cat. TD-2053 belt pouch. $ .95 Pocket Knife with Removable LED Torch Ideal for fishing or camping! The half serrated 70mm blade locks into place to prevent it from slipping, and the bright LED torch can be removed for Cat. TH-1902 use.100mm long when folded. $ .95 Must be over 16 years old to purchase. 9 24.95 $ Floats if dropped in water! It is completely waterproof, and stands about 160mm tall. Was $12.95 How far is the next turn off? Automatically convert a map’s scale distance to real distance by rolling the small wheel along the desired route. It works with any map scale and displays in kilometres or miles. Cat. XC-0375 19 $ .95 Cat. ST-3033 9 $ .95 SAVE $3 1W Luxeon LED Head Torch 12V Camping Shower 29 Cat. MP-3014 Mini Waterproof Camping Lantern Digital Map Distance Calculator Fishing Tool Set 4 9 .95 A touch of luxury! Wash away the cares of the day no matter how far from civilisation you are! The camping shower allows you to take a shower wherever you are. Cat. YS-2800 Powered by your $ .95 vehicle’s 12V battery. 19 8L Collapsible Bucket No need for wasted storage space! This bucket collapses down to just 255 x 35mm when not in use. Measures 255 x 230mm Cat. GH-1260 $ .95 open with an 8 litre capacity. 14 Ultra bright! This compact little beauty will light up like no other. It produces extremely bright, super white light, all from a lightweight and compact package. Requires 3 x AAA Cat. ST-3321 $ .95 batteries. 69 5W Luxeon LED Hand Torch Blinding white light! If you need a super bright torch, this one’s for you. It houses a super bright 5W Luxeon LED which is the brightest on offer at 120 Lumens. Requires Cat. ST-3338 SAVE $ .95 6 x AA batteries. $20 Was $149.95 129 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au Camera and Equipment Cases A worthwhile investment! Protect your valuable camera, mobile phone, or PDA with a tough carry case. The outer case is made from semi-hard PVC with soft fabric lining, this case is able to be attached to almost anything using the carabineer. Three sizes available: Small: 85(L) x 37(H) x 115(D)mm $8.95 Cat. AR-1440 Medium: 80(L) x 35(H) x 131(D)mm $8.95 Cat. AR-1442 Large: 105 (L) x 60(H) x 130(D)mm $9.95 Cat. AR-1444 Neck Cooling System Beat the heat! Keep cool and comfortable while wearing this device around your neck. A quiet motor drives a tiny fan to create an evaporative cooling system. Add a few drops of water to the neck cooler and Cat. GH-1759 $ .95 away you go. Supplied with a water bottle for evaporating. 29 Novelty Dripping Sound Box Select your victim! Just hide it in a someones bedroom, and it will make a sound like a dripping tap until they turn on the light. It will infuriate them while they try and find it, only for it to stop when exposed Cat. GT-3280 tolight again! $ .95 49.95 Get a great massage on the go! It fits over most seats with the use of elastic straps, and the built in heater has three different heating levels. Three independent motors target the upper back, lower back, and thighs. Cat. GH-1753 Supplied with car and $ .95 mains adaptors. 49 Anti-Fog 5" Shaving Mirror with FM Radio The Amazing Flygun! Cat. GT-3282 14.95 $ Electric Shock Reaction Game $ Optional Voice Cards 34.95 Love to hate it! It sounds just like a mosquito when hidden in a dark spot. It will infuriate someone while they try and find it, only for it to stop when exposed to light again! Cat. GH-1095 Remote Controlled Massage Seat Cover Pad with Built in Heater 29 $ Novelty Buzzing Mosquito Box Keep the kids entertained! The Amazing Flygun is a safe, fun, and effective method of killing flies and mosquitoes. Launch the spring powered swatter at your target! It is safe, fun and really does work! Cat. YS-5545 KILLS $ .95 COCKROACHES TOO! 7 Shocking Lie Detector Liar liar, pants on fire! Your mates will tremble as you question them about the size of fish they say they caught. If they lie, they will receive a mild shock. Great fun at your next party. HONEST! As seen on Channel 9’s Merrick and Rosso Unplanned, dubbed... The Pain Machine! Great fun for the whole family! The missiles launch spectacularly into the air with the use of the hand pump. They launch Cat. GT-3006 over 30m into $ .95 the air! 29 44.95 Shocking Tank Battle Set Novelty Boss Voodoo Doll 19.95 $ Show your boss what you really think! Twist his arms, break his legs, and he will be begging for you to Cat. GT-3104 $ .95 come back to work with a pay rise. Great fun for every one. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 English, French, & German English, Spanish, & Italian Mandarin & Japanese INTERNET> www.jaycar.com.au $24.95 $24.95 $19.95 XC-0187 XC-0188 XC-0189 Talking Digital Watch with Alarm Don’t be late! This watch announces the time at the touch of a button. It is great for young children to help read the time, or the vision impaired. It has various alarm sounds to get you out of bed including a rooster crow. Cat. XC-0258 19.95 $ Noise Cancelling Headphones Sleep soundly! They are designed for use in noisy environments such as an aircraft or cars reducing background noise by as much as 15dB. Powered by two AAA batteries (included), they come with a Cat. AA-2054 1.8m lead terminated $ .95 with a 3.5mm stereo plug. 49 Portable Plasma Ball A sphere of magical plasma light that you can take anywhere! It creates a dramatic display of multicoloured light under a handblown glass dome. Requires 2 x AA batteries and measures Cat. GH-1527 135(Dia) x 145(H)mm. $ .95 39 Plasma Clock Stylish and functional! With the option of table or wall mounting, the cool electric blue glow of the plasma will add a new dimension to your décor. It measures 291(H) x 177(W) x 107(D)mm, and a mains adaptor is included. Cat. GH-1525 59.95 $ 4 in 1 Mars Rover, Boat & Submarine This thing will go anywhere! Whether it is driving over rough terrain, crossing water, or diving deep into it, this great craft will do it. It uses a skid steer drive system, or detach the wheels for full use of the props. Cat. GT-3420 Approx 180mm long. $ .95 49 99.95 $ BOTH COLOURS 29.95 $ $ Cat. GH-1099 Electronic Toy Safes Ideal protection against… siblings! Features an illuminated keypad and programmable combination, with voice or sound effects. Pink Cat. GH-1310 Blue Cat. GH-1311 •185(H) x 135(W) x 125(D)mm. Cat. GH-1093 Remote control battles with a twist! These futuristic looking remote control tanks have IR cannons to fire at each other.Look out though, if you get hit, you will receive a mild shock! Great fun. •Supplied as a pair. Air Powered Rocket Launcher and Pump 11 Language Talking Translator Over 700 phrases! It can cross translate between eleven languages on its own, and by using the optional voice cards, it can play them at the touch of a button. It has a host of other functions and is a must-have for overseas Cat. XC-0186 travellers. Shave in the shower and save time! This 'anti-fog' mirror won't get steamed up, has a digital clock, and an AM/FM radio. Supplied with handy razor holder, suction cups, screen hook and hanger cord. Cat. GH-1057 14 How quick are you? Wait for the light to change from red to green, then hit the button. If you are the last, you will receive a mild shock, but don’t jump the gun or you will get one too! Bookmark Electronic Dictionary So slimline it’s a bookmark! Holding a vocabulary of over 50,000 words, this dictionary’s vocabulary is about five times better than the average human. The flexible keypad fits neatly between pages, and it even has calculator Cat. XC-0185 and alarm functions. $ .95 24 Novelty Animated "Fat Bastard" Doll A must for Austin Powers fans! The Scottish-accented, repulsive character from the movie is a barrel of laughs. He will belch, fart, or say one of eight hilarious Cat. GT-3106 phrases. $ .95 Ltd qty. 29 5 Piezo Pocket Gas Torch Compact size! It is ideal for heating small objects, camping, and more! It has an adjustable flame up to 1300oC, and uses standard Butane gas. Was $14.95 SAVE $5 Cat. TS-1662 $ .95 9 Solder Flux Pen Ideal for SMD rework! Applying the flux to solder joints will aid re-flow when heating to remove components, or it can be applied to tracks for excellent Cat. NS-3035 SAVE solder-ability. Was $12.95 $ .95 $3 9 Surfboard SMD Soldering / Handling Trainer Kit SMD made easy! It consists of a PCB with many different pad sizes, which SAVE $5 conform to standard SMD component dimensions. It even includes components and instructions to Cat. KJ-7000 make a working twin LED flasher – all $ .95 with SMD! Was $24.95 Vacuum Bench Vice 18W Professional Soldering Iron Die-cast aluminium construction! Great if you only occasionally need a vice on your workbench. It attaches and detaches without leaving a mark. Was $57.95 Cat. TH-1766 $ .95 SAVE Perfect for precise soldering! It offers rapid heat up, instant recovery, stainless steel barrel, and iron clad chrome plated tip. $10 Was $34.95 Cat. TS-1551 $ .95 DURATECH Soldering Iron 40W Bench-top Work Mat Protect your bench! This durable A3 (450 x 300mm) PVC cutting mat is just the thing to protect your work bench from damage. You can cut, solder, write, and not risk damage to your bench-top. Was $9.95 SAVE $5 29 47 SAVE $2 Cat. HM-8100 $ .95 7 Ideal for hobbyists and handy-work! Stainless steel barrel, and an orange cool grip, impact resistant handle. Mains powered, fully approved. Cat. TS-1475 SAVE Was $16.95 $ .95 $4 12 PCB Etching Kit 60W SMD Soldering Tweezers An ideal kit to get started! Includes an assortment of copper boards, etching solution, tweezers, a photosensitive PCB and developer. Cat. HG-9990 Was $24.95 $ .95 The best way to SAVE solder SMD. $30 Solder and desolder small components or large flat pack ICs. Tips available from 2 to 20mm. 2mm Cat. TS-1700 tips supplied. $ .95 Was $99.95 SAVE $5 19 69 19 SAVE THIS MONTH ON SELECTED TEST EQUIPMENT! Low Cost DMM •10A current. •Transistor test. •Diode test. Was $9.95 SAVE $2 Data Hold DMM •10A current. •Low battery indicator. •Includes holster. Was $14.95 SAVE $4 Cat. QM-1520 $ .95 Cat. QM-1500 $ .95 Frequency DMM •Temperature. •Capacitance. •Auto power off. Was $49.95 SAVE $10 Cat. QM-1320 $ .95 Inductance DMM •Capacitance. •Temperature. •Transistor test. Was $49.95 SAVE $10 True RMS Auto Ranging DMM •Frequency. •40M ohm resistance. •Duty cycle. Was $79.00 SAVE $10 Cat. QM-1536 $ .00 69 IDEAL True RMS DMM •High speed analogue bargraph. •Relative measurement. •Duty Cycle. •Cat III 600V. •Limited lifetime warranty. Was $449.00 Cat. QM-1625 $ .00 399 6 SAVE $50 RS-232 Auto Ranging DMM Auto Ranging DMM •Capacitance. •Bargraph. •Frequency. Was $59.95 •Duty cycle. •Relative measurement. •Frequency. Was $69.95 SAVE $15 Auto Ranging RS-232 DMM •Dual temperature. •Cat III 1000V. •4000 count. Was $139.95 Cat. QM-1460 $ .95 129 SPECIAL BONUS! Buy an Ideal multimeter and receive a mini Ideal bottle opener FREE! While stocks last. SAVE $10 Cat. QM-1530 $ 95 44 SAVE $10 Cat. QM-1290 $ .95 Cat. QM-1628 $ .00 299 Cat. QM-1440 $ .95 49 199 •200A AC current. •Vibrating AC voltage detection. •Audible dangerous voltage. •Cat III 1000V. •Limited lifetime warranty. Was $349.00 59 •RPM •15A current. •Dwell angle. Was $59.95 •20A current. •Recording. •Bargraph. Was $229.95 IDEAL True RMS Clamp Meter Cat. QM-1538 $ .95 Dwell Tacho DMM Protek 506 - Auto Ranging DMM SAVE $30 Cat. QM-1535 $ .95 27 19 39 SAVE $10 SAVE $7 Cat. QM-1526 $ .95 Cat. QM-1445 $ .95 39 •Capacitance. •Relative measurement. •Frequency. Was $34.95 SAVE $5 10 7 Auto Ranging DMM Backlit Temp DMM •Professional look. •Continuity tester. •Data hold. Was $24.95 10MHz Velleman Handheld Oscilloscope •True RMS. • dB measurement. •10MHz sampling rate. •High resolution LCD. •Screen hold. Was $349.00 SAVE $50 SAVE $50 Cat. QC-1916 $ .00 299 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au NEW HARDCORE ELECTRONICS! Temperature Controlled Soldering Station Great value! It features a high quality ceramic heating element for accurate temperature control, adjustable between 200 and 480°C. The soldering pencil is lightweight, (45g excluding cable), so it is comfortable for long periods. It is a great station, so check out our website for details. In Stock Cat. TS-1560 $ .00 Now 99 High Quality CAT III Multimeter Probes A must for the professional! They are made from strong silicon rubber for durability and flexibility, with adequate strain relief and finger guards. Rated at CAT III to pass 15A of current. 900mm Cat. WT-5335 Cat. WT-5335 120mm Cat. WT-5337 $ .95 24 This section is dedicated to what’s new for the Hardcore Enthusiast. High Power Luxeon LEDs Multi Function ESD Safe SMD Rework Station The brightest LEDs in the world! •Up to 25 Lumens per 1W LED. •Up to 80 Lumens per 3W LED. •Up to 120 Lumens per 5W LED. •100,000 hours life expectancy. •Fully dimmable. •Superior ESD protection. Complete SMD working at your fingertips! This robust unit features a soldering pencil, and hot blower for all rework applications. The soldering pencil and hot blower have individual temperature adjustment, and the air flow can also be varied. It is ESD safe for sensitive components, and is ready to tackle a myriad of tasks. See our website for details. Cat. TS-1570 $ .00 449 In Stock Now 29 Quick and easy! Checks AAA, AA, C, D, and 9V(N) type batteries, and indicates their power level on the easy-to-read, colour-coded analogue display. Also checks bulbs and fuses giving a "good" Cat. QP-2252 or "replace" indication. $ .95 150mm long. 9 IDEAL Non-Contact 60 - 400VAC Tester Red Orange Green White Royal Blue 5W White LED ZD-0440 Cat. QP-2274 $ .95 29 Digital PH Meter with LCD Simple but effective! It uses three LEDs to indicate battery voltage, and another three to indicate over-voltage, max voltage, and charging status. It includes 600mm leads and a magnetic base to secure it while testing. Cat. QP-2258 $ .95 55Pc Computer Service Tool Kit For the serious serviceman! Housed in a soft leather case, it contains a range of tools suitable for computer servicing. It is a must for service people and anyone who does their own computer servicing. Was $65 Cat. TD-2051 SAVE $ .00 $15 SAVE $3 Super Torque Driver Ratchet Torque transfer compound. It dramatically increases the amount of torque you can apply to a screw head without slipping. 14g bottle. Was SAVE Cat. NM-2830 $13.95 $3 $ .95 Comfortable driving! It accepts standard driver bits, adjustable and lockable head angle, with a rubber grip handle. Was $13.95 10 Teletaper - Telephone Audio Tool 49 SAVE $30.05 INTERNET> www.jaycar.com.au Cat. ZD-0420 $ .95 9 Cat. ZD-0422 $ .95 9 SAVE $4 Industrial quality on a budget! This fantastic unit has a FULL cast iron bed, frame, and head stock assembly, just like industrial lathes. It bristles with safety features including a plastic chuck cover which must be down for the machine to operate. This prevents you from starting the lathe with the chuck-key in! We have not seen a product of this quality, at this price. See website for details. The cutting tools, drill chuck, and live centre and all usually sold extra, costing over $100 more, but are included in $107.80 the price! worth of parts Was $899 already included! 9 Cat. TL-4000 $ .00 799 The ULTIMATE driver bit set! It contains just about every driver bit you will ever use! They are all made from strong tool steel, and are built to last. See our website for the full list of what’s inside. Was $16.95 Cat. TD-2038 SAVE $ .95 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 Luxeon LED Lenses Wide and narrow beams! These lenses are used to evenly distribute light in the desired way. Wide beam lens Cat. ZD-0420 Narrow beam lens Cat. ZD-0422 Cat. TD-2033 $ .95 100Pc Driver Bit Set 13 1+ $29.95 10+ $26.90 25+ $20.70 Precision Mini Metal Lathe Deal 50 Screwdriver Helper Record phone conversations! It is designed for use in call centres where a supervisor can listen to, or record the conversation. NOT AUSTEL APPROVED. Cat. QC-1990 Was $80 $ .95 ZD-0439 149 No toolbox should be without one. Strips wire from 0.9mm to 5.5mm, made from a hardened Cat. TH-1825 alloy steel with rubber $ .25 handles. Was $12.25 1+ $17.95 10+ $15.95 25+ $12.35 3W White Side Emitting Extremely bright! This laser module consists of a 10mW laser diode, lens, and driver PCB. Simply connect a 3VDC supply, and you have a great high power laser. Datasheet included. Cat. ST-3117 $ .95 •Measures 65(L) x 11(dia)mm. Wire Stripper / Cutter Pliers 9 ZD-0407 10mW Green Laser Module 79 1+ $69.95 10+ $62.95 25+ $48.90 1W White Side Emitting 9 Simple and accurate! Useful for checking pH levels in water, fish tanks, swimming pools, and more! It is great in a chemical lab for testing and checking solutions, and the large LCD is easy to read. It has a range of 1 – 14pH, 0.1pH resolution, and +/-0.2pH accuracy. Cat. QM-1670 $ .95 $14.95 $14.95 $16.95 $16.95 $16.95 White ZD-0430 Red ZD-0432 Orange ZD-0434 Green ZD-0436 Blue ZD-0438 3W LEDs 1+ $29.95 10+ $26.90 25+ $20.70 Battery / Charger / Alternator Tester Great for every tradesman’s pocket! Gives an audible and visual indication on energised circuits. It has an unlimited lifetime warranty, and is rated at CAT III 600V ZD-0400 ZD-0401 ZD-0402 ZD-0404 ZD-0406 3W LEDs Battery Bulb and Fuse Tester Cat. WT-5337 $ .95 1W LEDs $3 SAVE $100 Digital Vernier Caliper No more eye strain taking readings! Cat. TD-2082 $ .95 79 The clear LCD shows the exact measurement in millimetres or inches, so there is no guesswork involved. •Accurate to 0.01mm. 7 IR Remote Control Tester Kit Includes auxiliary output! Ref: Silicon Chip January 2005. It lights an LED and sounds a buzzer if an IR code is detected. It also features an output for further analysis on an oscilloscope. Kit supplied with PCB, case, and all electronic components. Operating Fuel Cell Powered Model Car 20W "Schoolies Amp" Kit Contains an actual working fuel cell! You are provided with the equipment to make the Oxygen and Hydrogen fuel (by electrolysis) and then burn it in the fuel cell to make electricity! The package comes with an illustrated 90+ page text with suggestions for 30 experiments, and all model parts. Cat. KC-5407 $ .95 19 29 V8 Sounding Doorbell Kit A Jaycar Exclusive Cat. KT-2500 $ .00 299 A must for car enthusiasts! Ref: SC Jan 2005. Be the envy of your mates as they hear the rumble when they press your doorbell. You may have seen commercially available units, but nothing like this. It sounds just like a V8, and has variable background noise for tappets and valves etc, for an even more realistic effect. 2 versions available: Quick and easy! Ref: SC Dec ’01. Adapts to PC motherboards that have provisions Cat. KC-5323 for on-board IR support. Includes .95 PCB and all electronic components. $ 21 Supplied with PCBs, silk-screened & machined case, push button bell switch, speaker, hook-up wire, & all electronic components. Includes the Cat. KC-5405 optional 120mm length of 100mm $ .95 diameter pipe for that extra rumble! Luxeon Star LED Driver Kit 79 Short Form V8 Doorbell Kit Contains the working electronics only. Supplied with PCBs, and all electronic components. No Cat. KC-5406 .95 case, speaker, or pushbutton etc supplied. $ YOUR LOCAL JAYCAR STORE NEW SOUTH WALES Albury Ph (02) 6021 6788 Bankstown Ph (02) 9709 2822 Bondi Junction Ph (02) 9369 3899 Brookvale Ph (02) 9905 4130 Campbelltown Ph (02) 4620 7155 Erina Ph (02) 4365 3433 Hornsby Ph (02) 9476 6221 Newcastle Ph (02) 4965 3799 Parramatta Ph (02) 9683 3377 Penrith Ph (02) 4721 8337 Silverwater Ph (02) 9741 8557 St. Leonards Ph (02) 9439 4799 Sydney City Ph (02) 9267 1614 Taren Point Ph (02) 9531 7033 Wollongong Ph (02) 4226 7089 VICTORIA Coburg Ph (03) 9384 1811 Frankston Ph (03) 9781 4100 Geelong Ph (03) 5221 5800 Melbourne Ph (03) 9663 2030 Ringwood Ph (03) 9870 9053 Springvale Ph (03) 9547 1022 QUEENSLAND Aspley Ph (07) 3863 0099 Brisbane - Woolloongabba Ph (07) 3393 0777 Gold Coast - Mermaid Beach Ph (07) 5526 6722 Townsville Ph (07) 4772 5022 Underwood Ph (07) 3841 4888 AUSTRALIAN CAPITAL TERRITORY Canberra Ph (02) 6239 1801 TASMANIA Hobart Ph (03) 6272 9955 SOUTH AUSTRALIA Adelaide Ph (08) 8231 7355 Clovelly Park Ph (08) 8276 6901 WESTERN AUSTRALIA Perth Ph (08) 9328 8252 NORTHERN TERRITORY Darwin Ph (08) 8948 4043 NEW ZEALAND Hamilton Ph (07) 846 0177 Newmarket - Auckland Ph (09) 377 6421 Glenfield - Auckland Ph (09) 444 4628 Wellington Ph (04) 801 9005 Christchurch Ph (03) 379 1662 Freecall Orders Ph 0800 452 9227 8 USB Power Injector Kit *This kit is not a toy. It is more a formal learning instrument than a kit for home consumption. PC Infrared Transceiver Kit Full V8 Doorbell Kit 49 A great low cost amplifier! Ref: SC Dec 2004. It uses a simple but effective design to give 20WRMS into a four or eight ohm load. Kit supplied with PCB, and all electronic components. Requires +/- 25V power supply, use KC-5347. Cat. KC-5403 .95 Heatsink not included. $ Power 1W, 3W, and 5W Luxeon LEDs from a 12V source! Ref: Silicon Chip May ‘04. Save $$$ off purchasing pre-built drivers. Kit includes PCB, and all electronic components. Fuel Mixture Display Kit Is your car running right? Ref: SC Nov ’95. It gives an indication of fuel mixture via 10 LEDs. Kit includes PCB and all electronic components. 29 Cat. KC-5399 $ .95 29 SMS Controller Kit Control appliances from anywhere! Ref: Silicon Chip Nov 2004. The SMS controller kit works with Nokia 3210, 3310, 5110, and 6110 models to control electronic outputs, and gives you a host of control options. The possible uses are almost endless! Kit includes PCB, preCat. KC-5400 programmed micro, and all electronic $ .50 components. Requires Nokia data cable. 49 The SHORT CIRCUITS LEARNING SYSTEM The Short Circuits learning system is a great way to learn electronics. It is fun, informative, and you build great projects along the way. Here is just one from Short Circuits 3… Guitar Practice Amplifier Kit Cat. KC-5195 $ .95 14 Universal +/- 15V Power Supply Kit Great for preamps! Ref: SC Aug ’88. Allows you to obtain +15V, -15V, and +/15VDC depending on configuration. Includes PCB and electronic components. Cat. KC-5389 $ .95 A power boost for your USB port. Ref: SC Oct 2004. This project allows full current to be drawn from USB peripheral devices. Kit includes PCB, case, silk screened and punched panels, and all electronic components. Don’t annoy the neighbours! It has a guitar type input socket, small speaker, and volume control. It sounds great! Kit supplied with PCB, speaker, socket, and all electronic components. Instructions are in the Short Circuits 3 book. Theremin Synthesiser Kit Cat. KC-5038 $ .95 13 Temperature Switch Kit Simple design! Offers a range between -30 to +130°C, set via a small trimpot with a relay output. Includes PCB, NTC thermistor, Cat. KG-9140 and electronic components. $ .95 21 Far cheaper than commercial units! Ref: SC Aug ’00. The Theremin Synthesiser produces those familiar science fiction movie sound effects when you move your hand between the metal plate and antenna. It has an amazing range from shrieks to growls, and is not just entertaining. The Beach Boys used a Theremin Also available prein their classic hit built and tested "Good Vibrations"! Cat. AM-4025 Kit supplied with $99 PCB,silk-screened and machined case, metal plate, Cat. KC-5295 antenna, speaker, and all $ .95 electronic components. Excellent functionality! This kit indicates via LED when the beam is broken. Includes PCB, IR RX/TX diodes, magnifying lens, and all electronic components. 11 Less emissions! Ref: SC June ’98. A high energy 0.9ms spark burns fuel faster and more efficiently to give you more Cat. KC-5247 power! Includes PCB, case, $ .95 and all electronic components. 52 Car Turbo Timer Kit LED Duty Cycle Meter Kit PRICES VALID TO END MARCH 2005 Cat. KG-9094 $ .95 High Energy Ignition Kit Performance Electronics for Cars Book Includes relay output! Operate an extra injector or water pump etc. when they reach a set duty cycle and a whole lot more! Includes duty cycle generator for testing. Kit includes PCB, and all electronic components. 14 5m IR Light Barrier Kit 44 Over 160 pages! The Performance Electronics for Cars Book from Silicon Chip publications has chapters on modification and theory, as well as the 16 projects. Here is just one… Cat. BS-5080 $19.80 Cat. KJ-8092 $ .50 Cat. KC-5375 $ .95 54 Save your turbo! It idles you car for a set time after ignition switch-off to aid in turbo cooling. Includes PCB, case, relay, and all electronic components. Cat. KC-5254 $ .95 29 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au PRODUCT SHOWCASE Hot stuff from DSE . . . Dick Smith Electronics have submitted some of their “Iroda” range of butane gas-powered tools. Three such items are shown above. On the left is the Solderpro 70k kit, a versatile 4-in-1 device which offers conventional soldering (equivalent to a 25-80W iron), hot knife, blow torch and heat blower functions, all in one handy package. Applications include electronics, light gauge welding, brazing, light plumbing, model building, arts and crafts, thawing locks and much more. The T-1105 Solderpro 70k kit has a recommended retail of $78.86. There is also a lower power version, the T-1103 Solderpro 50k (30-70W equivalent), which retails for $64.98. Both of these irons in these kits are also available as separate items: the Solderpro 50 iron (T1102) is $39.98, while the Solderpro 70 (T1104) is $49.96 Other products shown above are the T-1101 Pro Torch (centre) which sells for $49.94 and has many applications including brazing, plumbing, vehicle repairs . . . even a chef’s torch! It is refillable with butane. At right is the T-1100 Micro Jet, a nifty little torch which is powered by a refillable butane gas lighter (supplied, shown in front). This has a flame temperature up to 1300°C and has a windproof flame and waterproof ignition system. As such it also has applications in survival kits, camping and first aid. Recommended retail is $24.97. Note: due to the fact that these devices contain combustible gases, they are classed as a hazardous shipping item and therefore cannot be purchased on line or by mail order. They are only available to personal shoppers at Dick Smith Electronics or PowerHouse stores. Contact: Dick Smith Electronics (all stores) Aussie product wows ’em at Las Vegas CES The innovative “Infusion” Portable Wireless Internet Radio was short-listed as one of three finalists for the Best of CES 2005 Awards (“Audio To Go” category). The Las Vegas Consumer Electronics show is the world’s largest consumer electronics exhibition, attracting over 2600 exhibitors. Exhibited by Torian, a small Australian IT company, Infusion allows users to listen to any radio station in the world that streams through the World Wide Web, without the need of a computer. It’s around the size of a business card and allows travellers and those stationed abroad to stay in touch with local news, sports, and music. Torian believes it is the first Australian company to be short-listed for a major CES show award. Contact: Torian 204 Johnston St Collingwood Vic 3066 Tel: (03) 8415 1994 Fax: (03) 8415 1982 Website: www.torian.com.au STEPDOWN TRANSFORMERS 60VA to 3KVA encased toroids Reply Paid 500, PO Box 500, Regents Park DC NSW 2143. Tel: 1300 366 644 Fax: (02) 9642 9155 Website: www.dse.com.au New 400W Wind Generator from Oatley Following our featuring the 200W Wind Generator kit from Oatley Electronics (SC Dec 2004) and our current Windmill series, Oatley have advised that a new 400W Wind Generator is now available, priced at $599.00. With a 1.4m rotor diameter and a high-quality cast-aluminium body, this very efficient wind generator has siliconchip.com.au a very low start-up and cut-in windspeed. Further details are available from the Oatley Electronics website. Contact: Oatley Electronics PO Box 89, Oatley NSW 2223 Tel: (02) 9584 3565 Fax: (02) 9584 3561 Website: www.oatleyelectronics.com Harbuch Electronics Pty Ltd 9/40 Leighton Pl. HORNSBY 2077 Ph (02) 9476-5854 Fx (02) 9476-3231 March 2005  61 Ozitronics www.ozitronics.com Tel: (03) 9434 3806 Fax: (03) 9011 6220 Email: sales2005<at>ozitronics.com 4-Channel UHF Remote with Resets K180v3 - $82.50 Modified & improved version of original K180 kit. Now with individual resets on each channel when used in 'toggle' mode. Rolling code for high security. Pre-built 'keyfob' style transmitter. Prices include GST – shipping extra. Full documentation available from website. Jaycar Electronics opens in Hornsby Jaycar has opened a new store in the northern Sydney suburb of Hornsby, to service the needs of local professionals and electronics enthusiasts. Located on George Street, just 300m from Hornsby railway station, the store has plenty of room to display Jaycar’s full range of products and is staffed by enthusiasts who understand the products they sell. Products include car alarm systems, test equipment, video surveillance equipment, car audio, electrical and electronic tools, wire, cable, accessories and kits. Parking is plentiful with a number car spaces available at the front of the store as well as and on the roof-top car park. The store will employ up to five local staff and is located at 130 George St Hornsby and can be contacted on 9476-6221. Denon’s “ultimate” 10-channel home theatre amp “be·he·moth n. Something enormous in size or power.” It’s a term which aptly describes Denon’s most technologically advanced surround sound Home Theatre amplifier to-date, the AVC-A1XV. Boasting no less than 16-channels of output capability, (with 10 x 170W fully assignable channels), it can accommodate both audio and video from up to four independent sources and distribute them to four separate zones, with independent volume control to each. It is able to deliver a full 9:1 channel surround sound system or two discrete 5.1 channel systems in different rooms or a 7.1 channel system in the main room, 2.1 channel system in a second room and a mono system in a third. In addition, power to any or all of the zones can be turned on or off independently in order to reduce power consumption. The new Denon amplifier is compatible with every 6.1 and 5.1 channel surround sound format currently available, including Dolby, DTS and Dolby Pro-Logic II to THX Ultra2 Cinema and Music, as well as THX surround EX decoding. It also features THX 4.0/5.1/6.1 post processing and offers additional and useful DSP modes, making it the most technologically featured Home Theatre A/V amplifier on the market. The AVC-A1XV also boasts the widest range of video connections, including three HDMI, one DVI-D digital video port and no less than six high-bandwidth HDTV compatible component video inputs, plus IEEE – 1394 (Firewire) and RS232. SILICON CHIP WebLINK For the best in audio, the AV C - A 1 X V also boasts a total of 14 audio/video inputs and connections for up to two high-resolution sources such as DVDA or SACD. The AVC-A1XV also debuts Denon’s latest LINK III technology that allows a direct ‘link’ to accept digital SACD data from future Denon source units. A built-in Ethernet facilitates TCP/IP control capability and can accommodate any future software/firmware upgrades. The AVC-A1XV is the world’s first receiver to include twozone video conversion capability and HDTV switching with on-board video up-conversion that automatically converts S-Video or composite video input signals from DVD players, VCRs or camcorders to a high quality component video signal. This is an invaluable feature when using high-resolution plasmas, LCD TV monitors and projection Contact: systems. Audio Products Group The AVC-A1XV is 67 O’Riordan St, Alexandria NSW 2015 available at authorised Tel: (02) 9669 3477 Fax: (02) 9578 0140 Denon retailers. Website: www.audioproducts.com.au How many times have you wanted to access a company’s website but cannot remember their site name? Here's an exciting new concept from SILICON CHIP: you can access any of these organisations instantly by going to the SILICON CHIP website (siliconchip.com.au), clicking on WebLINK and then on the website graphic of the company you’re looking for. It’s that simple. 62 Silicon 62  S ilicon C Chip hip Our website is updated daily, with over 5,500 products available through our secure online ordering facility. Features include semiconductor data sheets, media releases, software downloads, and much more. JAYCAR JAYCAR ELECTRONICS ELECTRONICS Tel: Tel: 1800 1800 022 022 888 888 WebLINK: WebLINK: www.jaycar.com.au www.jaycar.com.au siliconchip.com.au Implantable body transceiver for medical applications Imagine a heart pacemaker (or other medical implant) that can radio data to a receiver . . . such things as device faults, even body abnormalities that might signal, for example, a looming heart attack or stroke? Or a pill you can swallow which will show your doctor (by video) what’s wrong inside you? It’s all possible, right now, thanks to an intelligent radio transceiver designed by Cambridge Consultants (UK & US). The design is intended for system-on-chip (SoC) solutions and provides control and communications suitable for implantable medical devices – a market currently growing at double-digit rates. The device will operate in the 402405MHz ‘MICS’ (Medical Implant Communications Service) frequencies – the band now emerging as a global standard – and offers a communications range of 2m when implanted under the skin. A key attribute of Cambridge Consultants’ design is exceptional power economy, consuming an average current of less than 1mA (less than 1.7mA peak), for a 0.05% duty-cycle, 400kbits/second bi-directional communications application. This would provide more than 10 years of activity from a lithium cell in a typical pacemaker application. However, the radio design also allows the chip to be used for other systems with short-term, high data rate communications requirements, such as swallowable video imaging. The low-IF (Intermediate Frequency) radio receiver architecture employed in this design, adapted from high-efficiency pager technology, also offers better immunity to interference than direct conversion receivers. The tiny device requires just 10 compo- Test Instruments Catalog Emona Instruments, the Australiawide electronic and electrical test instruments supplier, has released their 2005 Test Instruments Catalog. Australia’s only dedicated Test and Measuring Instruments catalog, it is available in hard copy or online. Covering 72 pages of instrumentation and equipment for electronics and electrical design, manufacturing, service and maintenance and education, the catalog lists thousands of products from acclaimed instrument and equipment manufacturers including Tektronix, GW, Rigol, TTi, Kikusui, Pico, Seaward, ProTag, Escort, Stag, to name Contact: a few and contains Emona Instruments hundreds of new PO Box 15, Camperdown NSW 1450 products for 2005. Tel: 1800 632 953 (for free copy) Website: www.emona.com.au nents, enabling subcutaneous radios to be the size of a button using systemon-chip technology. Applications include pacemakers, defibrillators, remote telemonitors, orthopaedic devices, pump controllers, nerve stimulators and swallowable imaging and diagnostic systems. Contact: Cambridge Consultants 451 D St, Boston, MA 02210, USA Tel: (0011 1 617) 532 4700 Website: www.cambridgeconsultants.com Output from a PC to a TV or projector Want to display you PC output on a TV or projector? Microgram can help with a solution which is totally external and does not require software drivers (hence no software clashes!). It supports resolution up to 1152 x 864 with a refresh rate of 60Hz, 1024 x 768 at 75Hz etc, in both PAL and NTSC systems. There is a VGA HD DB15M input connector and the following output connectors: VGA HD DB15F, Composite RCA, S-Video and RGB (for SCART). VGA MF, RCA MM and S-Video MM cables are included as is an IR remote control. SECAM is also supported on the Contact: RGB output. Rec- Microgram Computers ommended retail 1/14 Bon Mace Cl, Berkeley Vale 2261 price is $349.00 Tel: (02) 4389 8444 Fax: (02) 4389 8388 (Cat No. 3102-13) Website: www.microgram.com.au This valuable WebLINK Space for Rent! JED designs and manufactures a range of single board computers (based on Wilke Tiger and Atmel AVR), as well as LCD displays and analog and digital I/O for PCs and controllers. JED also makes a PC PROM programmer and RS232/RS485 converters. Jed Microprocessors Pty Ltd Tel: (03) 9762 3588 Fax: (03) 9762 5499 WebLINK: jedmicro.com.au siliconchip.com.au A 100% Australian owned company supplying frequency control products to the highest international standards: filters, DIL’s, voltage, temperature compensated and oven controlled oscillators, monolithic and discrete filters and ceramic filters and resonators. Hy-Q International Pty Ltd Tel:(03) 9562-8222 Fax: (03) 9562 9009 WebLINK: www.hy-q.com.au We specialise in providing a range of Low Power Radio solutions for OEM’s to incorporate in their wireless technology based products. The innovative range includes products from MK Consultants, the worldrenowned specialist manufacturer. TeleLink Communications Tel:(07) 4934 0413 Fax: (07) 4934 0311 WebLINK: telelink.com.au Want to be NOTICED? Without costing you a fortune? To reserve your place in SILICON CHIP WebLINK, email BENEDICTUS SMITH Pty Ltd info<at>benedictus-smith.com December 2004  63 MM arch 2005 63 arch 2005  63 Virtually all the parts for the Inductance & Q-Factor Meter are mounted on a single PC board, so building it is easy. Here’s how to assemble it, check it out and use it to make inductance and Q-factor measurements. Inductance & Q-Factor Meter Pt.2: By LEONID LERNER B UILDING THE INDUCTANCE & Q-Factor Meter is quite straightforward. Fig.9 shows the parts layout on the single PC board. Begin by installing the wire links. All of the links except one can be formed from 0.7mm tinned copper wire or similar. The link situated to the right of Q1 must be fashioned from light-gauge insulated wire instead. Follow up with the resistors and then continue with all remaining components in order of height. Note that the high-profile components must be mounted as far down on the PC board surface as possible, so as not to inter64  Silicon Chip fere with the keypad and LCD when they are installed in the case later. In fact, the tip of REG3’s metal tab had to be removed on the prototype, to clear the rear of the keypad. This can be done using a hacksaw (with the device held in plastic vice jaws) and then carefully filing the job to a smooth finish . Alternatively, you may be able to bend the regulator to achieve sufficient clearance. When installing the IC sockets, be sure to align the notched (pin 1) ends as indicated in the overlay diagram. Also, check that you have the banded (cathode) ends of the diodes (D1-D8) and the positive leads of the four polarised capacitors around the right way. The keypad and LCD are connected via lengths of 7-way and a 10-way ribbon cable respectively. On the prototype, an 8-way header is used at the keypad end, while two 6-way headers are soldered to the first six and last six contacts of the LCD module. We’ve not included these headers in the parts list because there are several ways the keypad and LCD ends of the cable can be terminated, as well as several types of LCD modules with varying pinouts. You could even solder the ribbon cables directly to the PC siliconchip.com.au Fig.9: follow this diagram when assembling your meter. In particular, make sure that all the high-profile components are seated as close to the board as possible. boards, leaving out the connectors. Trial fit the assembly in the enclosure first to gauge the required ribbon cable lengths. Wire up in accordance with the circuit diagram (Fig.5), noting that the pins of the LCD and keypad will not be in the same order as the wires on the ribbon cable. Finally, in preparation for testing, temporarily fit the three binding posts directly to the PC board in the large holes marked “A”, “B” and “E” on the overlay. The posts must be removed after testing and installed in the top of the case as described later. Basic checks & programming The unit requires a 7.5-9V DC, 200mA power supply. Care needs to be taken here as some 9V DC plugpacks supply much higher voltages when lightly loaded. This extra voltage translates to power dissipation in the 7805 regulator, which may cause it to overheat and shut down. If you’re using an unregulated plugpack with selectable output voltages, you may find that the “6V” or “7.5V” setting is sufficient. As the first step, apply power and check that the +5V and -5V supplies are present on pins 7 and 4 of the AD8055 (IC4) respectively. Also, check for -1.8V on pin 2. Next, adjust siliconchip.com.au This view shows the fully assembled prototype PC board. Note that the final version shown in Fig.9 differs slightly from this unit. March 2005  65 the data entry screen should appear on the LCD. To make measurements using an external tank capacitor, first remove the link between the “A” and “B” terminals if installed earlier. Next, connect a capacitor of a few nF in parallel with an inductor of a few mH between the “A” and “E” terminals. You can now enter the capacitance value. For example, if you’ve chosen an 8.2nF capacitor, press “8” and then “2”. The display will show “8.2” followed by “100pF”, which is the default multiplier. Pressing any key except “*” has the effect of rotating the choice between the 100pF, 1nF, 10nF, and 100nF multipliers. As we’re using an 8.2nF capacitor in this example, press any key once to select the 1nF multiplier. Press “*” once you’re satisfied with the two parameters. If you make a mistake, pressing “*” at any stage lets you enter a choice or abort a measurement. The display should now show the inductance, Q factor and test frequency. To make measurements using the internal capacitor bank, insert a link between the “A” and “B” terminals. Repeat the procedure above but note that only choices of 1.0 x (1nF or 10nF or 100nF) make sense here since only these values are present internally. Q readings with the internal capacitor bank suffer due to the 0.5W (approx.) dynamic series resistance of the transistors, which do the bank switching. This mode is to be used if you’re not interested in the Q and just want to make inductance measurements. After the range is chosen, the micro starts sampling at the maximum rate. The first few acquisitions are used to optimise the sampling rate and set a sampling delay if required. The latter occurs when the ringing saturates ABOVE: the LCD is glued in place behind the display window and is connected to the PC board via ribbon cable – see text. Note that the diode shown connected to the DC socket here is on the PC board in the final version (D9 in Fig.9). the potentiometer (VR1) for optimum contrast on the LCD screen. All you’ll probably see at this point are faint grey blocks of pixels, as the micro is yet to be programmed; simply adjust the pot to get the darkest possible pixels. An ISP programmer can now be connected and the program files LQMeter128.HEX and LQMeter128.EEP Table 1: Capacitor Codes Value 100nF 82nF 8.2nF 4.7nF 1nF 820pF 680pF μF Code 0.1µF .082µF .0082µF .0047µF .001µF   NA   NA EIA Code   104    823   822   472   102   820   680 IEC Code   100n       82n   8n2   4n7   1n    820p    680p loaded into the Flash and EEPROM memories, respectively. These files are available from the SILICON CHIP web site in a file named “LQMeter. ZIP”. If you don’t already have a suitable programmer, then check out the “AVR ISP Serial Programmer” project described in October 2002. Kits for the programmer are available from Jaycar Electronics (Cat. KC-5340). The microcontroller program occupies most of the available memory space. It is quite complicated but should you have the inclination, you can follow its operation in detail in the documented source code included in the download. You can get a top-level understanding of program operation from the flow chart in Fig.10. Operation Power up and assuming all is well, Table 2: Resistor Colour Codes o o o o o o o o o o No. 1 10 2 3 1 9 1 1 2 66  Silicon Chip Value 10kW 4.7kW 1.2kW 1kW 120W 100W 82W 56W 47W 4-Band Code (1%) brown black orange brown yellow violet red brown brown red red brown brown black red brown brown red brown brown brown black brown brown grey red black brown green blue black brown yellow violet black brown 5-Band Code (1%) brown black black red brown yellow violet black brown brown brown red black brown brown brown black black brown brown brown red black black brown brown black black black brown grey red black gold brown green blue black gold brown yellow violet black gold brown siliconchip.com.au This close-up view shows how the three 10mm tapped spacers are fitted to the binding posts (after first snipping off the non-threaded tips). The PC board is secured to these spacers using M3 x 6mm screws and star washers (see text). the input amplifier in the immediate aftermath of the pulse. After a valid sample is acquired the micro performs an FFT and the centre frequency is estimated. During a period of eight cycles, centre frequency and bandwidth measurements are performed and the average taken. Finally, the inductance, Q factor and centre frequency are calculated and displayed on the LCD. A complete acquisition, averaging and display period takes about 0.1s for the 10MHz micro. You may find that the large binding posts are useless when testing physically small inductors. This is easily addressed by making up two short test leads to plug into the binding posts. Each lead consists of an uninsulated crocodile clip soldered to a 4mm banana plug via a very short length of large diameter single-strand copper wire or similar. Housing The completed meter will fit neatly into a console-style instrument case. This should be done after it has been tested and found to be operating corsiliconchip.com.au Fig.10: this diagram gives a very basic idea of how the microcontroller program works. For specific details, check out the fully documented source code, which is available for download from the SILICON CHIP website. rectly, as the keypad and LCD are glued in place and will be difficult to remove later. An opening for the keypad must be cut out and holes for the DC socket and binding posts should be drilled as shown in the various photographs. Note that the binding post holes must be positioned accurately otherwise it will be impossible to assemble the unit later. This can be achieved by using the PC board as a template when marking out the holes. To give the finished unit a professional appearance, a faceplate can be cut from thin aluminium sheeting and fitted around the keypad. The easiest way to achieve this is to lightly mark out the contour of the keypad on the aluminium sheet using a scribe or needle and then drill four 8.5mm holes at the corners. Next, use a straight edge and Stanley knife to score the sheet front and back, joining the four holes at their perimeters. Cut away the centre of the piece to be removed, then place the sheet in a vice and bend along the scored marks. Work the metal back and forth at March 2005  67 Another view inside the completed prototype. The keypad and LCD are secured to the case using epoxy adhesive. Fig.11: check your PC board against this full-size etching pattern before installing any of the parts. 68  Silicon Chip siliconchip.com.au the bend and it will break off, leaving a clean edge. The LCD, keypad and faceplate can then be glued to the case using two-part epoxy adhesive. To achieve a good bond to this plastic, the mating surfaces should first be sanded to a rough finish. Make sure that the LCD is centred left to right when you glue it, otherwise some of the characters will not be visible. Note that even when centred, the entire display width is not visible through the case cutout. This is not a problem, as the program uses only 12 of the available 16 character positions. Binding posts The binding posts are first attached to the case using the supplied nuts and spring washers. Next, snip off the very tip of the binding posts, leaving just the threaded portion. The non-threaded part is not needed and would otherwise obstruct the PC board mounting screws. Now remove the two small M3 nuts and replace them with M3 x 10mm tapped metal spacers, tightening firmly. The PC board can then be held in place by attaching it to the three spacers using M3 x 6mm screws and star washers. Note that the screws and washers must also make good electrical contact with the copper on the PC board. If there is a problem attaching the PC board to the spacers on the binding posts, check for interference between the components and the rear of the keypad. Some minor component repositioning may be necessary to fix this problem. Final word In addition to L and Q measurements, some interesting physical phenomena can be investigated with this meter. First, wind a small choke with a few turns of enamelled copper wire around a Philips screwdriver and check its inductance and Q factor with the meter. Next, insert a small HF ferrite bead into the coil and observe that the inductance and Q factor increases, as expected. Now replace the bead with the blade of the screwdriver and observe that the inductance hardly changes and may even decrease, while the Q drops markedly. Ordinary iron is not a useful core siliconchip.com.au Par t s Lis t – Inductance & Q-Factor Meter 1 PC board, code 04102051, 139.7mm x 86.4mm 1 150mH miniature ferrite choke (L1) (Farnell 432-090) 1 black 4mm binding post (Jaycar PT 0454) 1 blue 4mm binding post (Jaycar PT 0450) 1 green 4mm binding post (Jaycar PT 0455) 1 6-way 2.54mm pitch header (for ISP connection) (Jaycar HM-3416) 1 2.1mm or 2.5mm panel-mount DC socket 1 20-pin IC socket 1 16-pin IC socket 2 14-pin IC sockets 2 8-pin IC sockets 1 16-character x 2-line LCD module (DSE Z 4170 or equivalent) 1 numeric keypad (DSE P 7810) 1 console style plastic case, 150 x 95 x 28.5/49.5mm (Jaycar HB-6090) 1 ribbon cable (see text) 1 miniature 10kW trimpot (VR1) 3 M3 x 10mm tapped metal spacers 3 M3 x 6mm screws & star washers Semiconductors 1 AT90S2313-10 microcontroller (IC5), programmed with LQMeter128.HEX & LQ-Meter128. EEP 1 74HC00 quad NAND gate (IC1) 1 74HC390 dual decade counter (IC2) 1 74HC4066 quad analog switch (IC3) 1 AD8055AN high-speed op amp (IC4) (Farnell 283-976) 1 MAX635ACPA switching regulator (IC6) (Futurlec or RS 655-442) 2 2N4250 or PN4250 PNP transistors (Q1, Q2) (Wiltronics) 6 2N2222A or PN2222A NPN transistors (Q3-Q8) 1 40MHz crystal oscillator module (OSC1) (Farnell 571-830) 1 LM334Z adjustable current source (REG1) 1 7805 +5V regulator (REG2) 1 LM337 adjustable negative voltage regulator (REG3) 1 1N60 germanium diode (D1) (DSE Z 3040) 7 1N4148 diodes (D2-D7) 1 1N4004 diode (D8) Capacitors 2 470mF 16V PC electrolytic 1 220mF 10V PC electrolytic 1 47mF 6.3V tag tantalum 11 100nF 50V monolithic 2 82nF 50V MKT polyester 1 4.7nF 50V MKT polyester 1 1nF 50V MKT polyester 1 820pF 50V ceramic disc 1 680pF 50V ceramic disc Resistors (0.25W 1%) 1 10kW 8 100W 10 4.7kW 1 82W 2 1.2kW 1 56W 3 1kW 2 47W 1 120W 1 130W Note 1: parts shown with catalog numbers can be obtained from the indicated distributor(s). Contact details for all distributors mentioned are as follows: (1) Dick Smith Electronics (DSE): www.dse.com.au (2) Farnell InOne (1300 361 005): www.farnellinone.com.au (3) Futurlec: www.futurlec.com (4) Jaycar Electronics: www.jaycar.com.au (5) RS Components (RS) (1300 656 636): www.rsaustralia.com (6) Wiltronics Research (1800 067 674): www.wiltronics.com.au Note 2: the 40MHz crystal oscillator module could also be obtained from an old 386/486 PC motherboard. material at RF. This is because its magnetic domains cannot keep pace with the fast changing RF field. Rather they vibrate ineffectively and generate heat, introducing nothing but losses SC into the tuned circuit. March 2005  69 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. Headlight reminder With the storm season recently upon us, it’s not uncommon to switch car headlights on during the daytime. Unfortunately, it’s easy to forget to turn them off again when parking, with the result being a flat battery. This circuit will sound an alarm if the ignition switch is moved to the “off” position while the car lights are on, reminding you to turn the lights off before leaving the vehicle. The circuit is simple but effective. A 555 timer (IC1) is configured as a free-running oscillator to drive a small piezo transducer. The pitch of the transducer is set by the resistor and capacitor connected to pins 2 & 6. Power for the 555 is derived from the dashboard lighting circuit. However, the piezo does not sound during normal operation, because the 555’s reset input (pin 4) is held low by transistor Q1. This transistor is switched on whenever accessory power is present, pulling its collector towards ground (0V). If the ignition is switched off but the lighting circuit remains powered, the loss of accessory power results in Q1 switching off and releasing the reset signal to IC1, sounding the alarm. A 220W resistor in series with the piezo protects the 555’s output (pin 3). Although most piezo elements have relatively high impedance, this drops as the frequency increases due to their capacitive nature. The square-wave output on pin 3 includes many harmonics, some extending well into the ultrasonic range. The unit fits easily into a small plastic box. I spliced mine into the wiring running to the cigarette lighter, which includes both accessories and panel lamp circuits as well as a chassis ground wire. The result fits neatly behind the ashtray, with no chassis bashing required! Bruce Colledge, Ferny Hills, Qld. ($30) data cable terminated with D-9 connectors is to be tested. Connect 0V to pin 5, +9V to pin 1, and four resistors in between. Plug in a 9V battery and then probe the connector at the other end of the cable with a multimeter as indicated. Broken, shorted or incorrect connections are all quickly evident using this method. Grant Walker, Lutana, Tas. ($25) El Cheapo cable tester Many cable testers have been published before, some quite complex, but here’s a cheap and simple alternative. It uses only a 9V battery, two mating connectors and a few resistors, as well as a multimeter for voltage measurements. Begin by soldering the leads of a 9V battery clip between the two pins furthest apart on one of the test connectors and then add a ladder of resistors between them for each of the other required pins. Any junkbox resistors will do but values between 1kW and 50kW are best. In the example shown, a five-core 70  Silicon Chip siliconchip.com.au Aviation intercom Before its move offshore, I was lucky enough to be involved in developing the avionics system for the Flightship Ground Effect FS8 craft (see www.pacificseaflight.com/ craft.shtml). Although officially classed as a boat, it has wings and can travel at 180km/h some three metres above the water. The communications system was adapted from an aircraft unit and was a particular problem. It was expected to allow speech between the two pilots and radio, as well as receive audible warnings from the onboard computers and feed sound to the onboard data logger. Initially, the system was very noisy due to ground loops and incompatibility problems. A circuit similar to that shown here was the solution. Although optimised to suit Softcom brand headphones with active noise reduction, it should be suitable for most aviation sets. The plugs indicated are standard aviation types but are insulated from the instrument panel to eliminate earth loops. The inputs from the two pilots' microphones are summed and amplified by transistors Q1 & Q2. When one pilot presses his or her transmit key (mounted on the yoke), the transmit relay (RLY1) closes, muting the other pilot’s microphone via the optocoupler (OPTO1). The outputs from the microphone preamp, computer audio transformer (T1) and radio speaker transformer (T2) are summed via 10kW resistors and applied to the input of IC1, an LM386 audio amplifier. Note that transformers are used here to avoid creating additional earth loops. The output of the LM386 drives the pilots’ headphones via transformers T3 & T4, which are needed for impedance matching. Each audio source has its own level control (VR1, VR3 & VR4). The main volume control (VR5) is included to allow for ambient noise level. VR2 is used to set the signal level for the data logger. Gary Smith, Montrose, Tas. siliconchip.com.au Gary S is this m mith o winner nth’s o Peak At f the las LCR Meter March 2005  71 Circuit Notebook – Continued Touch lamp remote A bedside table touch lamp can be awkward to reach in the dark. However, its very easy to position one or more additional “touch pads” wherever you desire, using just a length of insulated wire and any suitable metal object. How? Well, simply strip both ends of a length of insulated wire, attaching one end to the touch surface of the lamp and the other end to a conductive surface. That’s it! The touch pad can be almost any conductive surface that is not earthed and is safe to touch. You could even use a metal bed head but this is not recommended – I found the lamp kept being switched on by accidental touches to the bed head. I’ve used a small metal costume jewellery broach but you could even use a thumbtack. Caution: don’t push the wire inside the lamp, as contact with the internal 240VAC wiring may prove fatal! Andrew Hicks, Harris Park, NSW. ($20) Simple under-voltage cut-out Sensitive low-current relay coils often operate at much lower voltages than their typical ratings. This can be undesirable in some applications, where low supply voltages can result in erratic system behaviour. In some instances, this problem could be overcome simply by inserting an appropriate value zener diode in series with the relay coil. This reduces the voltage seen by the relay coil, so causing it to drop out earlier. If desired, a LED could be included when a spare set of “normally closed” contacts are available to indicate relay dropout. Jay Williams, Baldivis, WA. ($20) Reverse polarity protector A series diode is often used as a means of protecting equipment from accidental power supply reversal, particularly in battery-powered equipment. Due to forward voltage losses, this is sometimes impractical. One solution is to use an enhancement mode P-channel power Mosfet (Q1) in series with the positive supply rail. A device with low drain-source “on” resistance can be selected to minimise voltage losses, which in turn extends battery life 72  Silicon Chip and reduces heat dissipation. Zener diode ZD1 must be included to protect against excessive gate-source voltage, while a 100kW resistor limits zener fault current. A second 100kW resistor across the output ensures that the gate doesn’t float when the input is disconnected. A series fuse and bidirectional transient voltage suppressor (TVS1) could be included to provide overvoltage protection, if desired. If common input & output grounds are unimportant, then a version of this circuit employing an N-channel power Mosfet in series with the negative (0V) rail could also be employed. Bruce Griffiths, Hamilton, NZ. ($25) siliconchip.com.au PICAXE freezer thermostat We have a portable 12V 18-litre freezer that’s had a chequered career as the boat’s freezer. Its innards were replaced about 18 months ago but then the thermostat failed in the “on” position. Being part Scottish, I was loath to throw it away. I was sure I could get a PICAXE-08 to make it work so I bought a thermistor from DSE and proceeded to experiment. The circuit shown was constructed and the trimpot (VR1) initially set to about 100kW. The freezer was then switched on and the voltage at pin 6 of the PICAXE was recorded at 5-minute intervals, along with the values from the readadc command. After the freezer reached about -14°C, power was switched off and more readings were taken to determine the warm-up rate. From this data and after some experimentation, I decided to run the compressor for five minutes if the temperature was above a certain threshold or three minutes if below. Once the temperature reached a lower limit, it would stay off for five minutes. This method adds hysteresis into the system, preventing rapid on-off cycling. It also helps ' Thermostat for Waeco 18-litre freezer symbol LED = 0 symbol relay = 4 symbol voltage = b1 symbol on_time = b2 symbol off_time = b3 symbol minute = b4 start: high LED wait 2 low LED wait 2     'show program is running main: readadc 1, voltage    'read from thermistor debug voltage if voltage <= 43 then relay_off if voltage > 43 and voltage <=64 then relay_on2 if voltage > 64 then relay_on1 goto main relay_on1: high relay siliconchip.com.au on_time = 5 for minute = 1 to on_time high LED wait 60 next minute goto main to minimise current drain on the batteries. As a result, the unit runs to about -11°C and with the 5-minute off period, it comes back to about -5°C or -6°C; enough to make ice cubes for the Scotch. More importantly, it should also keep any frozen meat in good condition for our trips! The freezer will eventually get down to -21°C if allowed to run continuously but with the law of diminishing returns, it takes far more energy to get down that far and of course, it warms up more quickly. Paul Rodenhuis, Port Bundaberg, Qld. ($40) CONTRIBUTE AND WIN! relay_on2: high relay on_time = 3 for minute = 1 to on_time high LED wait 60 next minute goto main relay_off: low relay low LED off_time = 5 for minute = 1 to off_time wait 60 next minute goto main As you can see, we pay good money for each of the “Circuit Notebook” contributions published in SILICON CHIP. But now there’s an even better reason to send in your circuit idea: each month, the best contribution published will win a superb Peak Atlas LCR Meter valued at $195.00. So don’t keep that brilliant circuit secret any more: send it to ILICON CHIP and you MS arch 2005  73 could be a winner! A SHIELDED ANTENNA FO RECEPTION This new tuned and shielded loop antenna can dramatically improve AM reception and is ideal for use when camping, caravanning or when you’re in remote areas where signals are very weak. It will help you chase far-away stations when closer ones are on the same frequency. It can also help where there is a lot of electrical interference. T he loop antenna goes back to the early days of radio when every ounce of signal you could get was needed. Long wire antennas picked up more signal but they also picked up all the static and other interference, often resulting in bad reception. The loop antenna improved the situation in being both tuneable and directional, thus maximising the wanted signal and minimising the unwanted signals and noise. The end result was a greatly improved signal-to-noise ratio and the possibility of digging almost unreadable signals out of the noise. A loop antenna of reasonable size will pick up far more signal than the more modern ferrite rod antenna which was introduced mainly because it was smaller and fitted in with re74  Silicon Chip ceiver miniaturisation. This new loop antenna, called the Techniloop MS1, supersedes the model PX1 which was described in the June 1989 issue of SILICON CHIP. The new model has contemporary styling plus the addition of shielding (Faraday shield) to further reduce noise and give a deeper directional null of interfering signals. The loops used in early radio typically took the form of a square timber or Bakelite frame wound with many turns of insulated wire to form a large coil which was tuned with an airspaced tuning capacitor. This worked well but was cumbersome and not too pretty (except perhaps to today’s collectors who often pay big prices for these vintage items). The Techniloop MS1 is much better looking and uses modern IDC ribbon cable and connectors mounted on a PC board to produce a highly repeatable loop coil of consistent performance. Tuning is by means of a speciallysourced 500pF variable capacitor and the whole of the circuitry is enclosed in an aluminium (therefore non-magnetic) shield, arranged so as not to form a shorted turn around the circumference of the loop coil. The diagram of Fig.1 shows the circuit of the Techniloop MS1, while Fig.2 is a more graphical depiction showing how the strands of the ribbon cable are connected to form the loop. The effect of shielding the loop is to cause the loop to respond only to the magnetic field component of the radio signal and not to the electric field. This enables virtually complete canceling of a signal when the loop siliconchip.com.au LOOP OR DX AM By David Whitby siliconchip.com.au March 2005  75 500pF 500pF SHIELDED TUNED LOOP ANTENNA Fig.1 (above): the circuit of the tuned antenna could hardly be simpler: a tapped coil with a variable capacitor across it. That forms a “tuned circuit” and at one particular frequency, which depends on the setting of the tuning capacitor, the tuned circuit becomes resonant. Fig.2 (right): a more stylized view of the circuit showing how the individual wires of the ribbon cable are connected together to form a continuous coil (or, more correctly, two coils). R,T & S stands for the plug ring, tip and shield. is at 90° to the station direction and often makes it possible to separate stations that are on the same or close to the same frequency but in different directions. Shielding the loop antenna also helps to improve the signal-to-noise ratio. Historically, shielded loops were (and still are) used on shipboard and aircraft radio direction finding equipment, mainly to provide deep nulls for accurate direction-finding and particularly in the case of aircraft, to eliminate what is known as” rain noise”. (Rain hitting an unshielded loop at high speed causes electrostatically-generated noise). Improves AM reception The Techniloop MS1 can dramatically improve AM radio reception over long distances both on receivers that have inbuilt ferrite rods or small loops and those that have external antenna connections. It will have particular appeal to country listeners, travellers/ caravaners, DX enthusiasts and flat dwellers and others in locations where AM reception is poor. Interstate reception at night is greatly enhanced. Even during the daytime, in Melbourne for example, many Tasmanian stations have been received strongly when without the loop they were just above the noise and even Sydney stations have been received in the late afternoon. A common application is with retirees or others who have moved a long way from their home town and found to their dismay that they can no longer An alternative arrangement, allowed for in the design, is for direct (ie, wired) connection where the radio receiver has external antenna and earth terminal(s). This allows the loop antenna to be remotely mounted in a better position for RF pickup (on a caravan roof, perhaps?). 76  Silicon Chip siliconchip.com.au Putting it together . . . step-by-step 1) Mount the seven tapped hexagonal spacers to the inside of the diecast case lid, using the 3mm countersunk screws supplied. Try to get the flats of the spacers parallel with the long sides of the lid, to allow maximum room for the loop frame to fit between the two rows of spacers. 2) Remove the protective paper backing from the supplied black adhesive foam rectangle and place it, adhesive side down, into the bottom of the housing lid, between the two rows of spacers. 3) Using the thin tinned copper wire supplied, make two long links on the non-track side of the PC board. Pull the wire tight and solder it to the PC board pads and trim. These wires form contacts to ensure that one end of the loop shield frame is firmly connected to the diecast case and to the PC board. The silver-coloured tape at the other end of the frame provides insulation to prevent the frame from becoming a shorted turn around the loop coil. siliconchip.com.au 4) Solder the tuning capacitor and the output jack socket to the PC board, using the hookup wire supplied. 5) Take the pre-assembled loop element and the PC board and carefully insert the IDC connector pins into the board as shown in the photographs (silver coloured tape end of loop to MS1 end of PC board. The track side of the PC board should be facing inside the loop). Do not remove the tape holding the loop element closed until the IDC connector pins are pushed fully into and soldered to the PC board, otherwise movement of the mitered corners of the loop shield may cause it to break. Before proceeding to the next step, check your soldering carefully – both visually, using a magnifying glass if possible, and electrically, using your multimeter switched to the Ohms range. Ensure that all pins of the IDC connectors have been correctly soldered to the PC board. Also check that no solder splashes are shorting out the closely spaced PC pads. There should be a couple of Ohms or so between adjacent pads. If less than this (especially zero!) the chances are you have a solder bridge shorting out pads. If more than this (especially infinity!), you have either a non-soldered pin or a dry joint. Correct any problems before moving on. 6) Gently lower the loop element/PC board assembly down onto the housing base between the spacers and onto the black foam pad. Line up the board mounting holes with the spacers and fasten with the 3mm screws supplied. 7) Fit the tuning capacitor and output socket to the case and tighten the screws. Gently lower the case/loop assembly down onto the lid (base) and fasten from underneath with the countersunk self-tapping screws supplied. Tightening these screws ensures the electrical connection between the two wire links on the PC board and the scraped section of the aluminium frame. 8) The protective felt pads should be fitted under the base after testing. March 2005  77 hear their old favourite station. In many cases, the Techniloop MS1 can solve the problem. Another situation common today is people moving into high-rise apartments and finding that AM reception is almost non-existent. Again, the Techniloop can usually solve the problem. Finally, if you wish to receive stations in the Australian AM Extended Band, in the range 1611kHz to 1701kHz, you need the Techniloop MS1. It is designed to tune over this range, as well as the normal AM band, so that you can more easily receive these low power stations. By the way, if you want the full list of stations in the Extended AM band, check them out at http://www.ardxc.fl.net.au/ stationlists/ Operating the Techniloop is simple. First, you tune in the station on your radio and align it for best signal pickup even if it is only faintly audible. You then bring the Techniloop close to the radio or if it is a portable, sit the radio right inside the loop as shown in the photographs. Then carefully tune the knob on the Techniloop to get the strongest signal. When you get the maximum pickup you will find that the tuning is very sharp. The increase in signal is magic! For radios with external antenna connections, a cable is supplied for direct connection to the set and sometimes this will give even better results. If we have made out that the Techniloop is a universal panacea for AM reception problems, that’s because it virtually is. Sure, it won’t give you Sydney radio stations in the Antarctic but it really does turn poor reception into good reception. We are very enthusiastic about it. The original Techniloop PX1 used a 300mm circular loop of 16 turns while the new MS1 model uses a 210mm square loop of 20 turns. In side-by-side comparison tests, the output from both loops was found to be virtually identical but the smaller size and sleek styling of the MS1 is much preferred, especially in the domestic environment. The Techniloop MS1 is available as a kit or fully built. Building the kit Building the kit is pretty straightforward because a lot of the really tricky work has already been done. 78  Silicon Chip Parts List – Shielded Loop Antenna 1 pre assembled loop element with fitted IDC connectors 1 diecast housing – drilled and powder coated 1 PC board 1 tuning capacitor & knob 1 3.5mm stereo jack socket 1 3.5mm stereo plug 1.5m figure-8 cable Hardware kit – bolts, nuts, spacers, felt pads & black foam rectangle Hookup & tinned copper wire Solder The Techniloop MS1 is available as a kit or fully built from: Gless Audio, 26 Park Street, Seaford, Vic 3198. Phone/fax: (03) 9776 8703; Mobile: 0403 055 374 Email: glesstron<at>msn.com Price for the kit is $110.00 plus $10.00 packing & postage*. Price for the fully built and tested version is $139.00 plus $10.00 packing & postage*. *Within Australia and New Zealand. The loop frame itself is already assembled. It consists of a folded square of powder-coat enamel finished aluminium extrusion which has been mitre-cut and has the ribbon cable already inserted and fitted with two IDC connectors. As supplied, it is taped up to hold its square shape. Don’t, whatever you do, unfold it because the corner hinge sections could easily break if they are flexed back and forth. The diecast aluminium case also is supplied drilled, machined and finished in powder-coat enamel to match the loop. All you need to do is to assemble the parts together and do the soldering. We suggest you follow the procedure shown in the separate panel. Testing & operation The most important testing is part of the assembly process: ensuring that you haven’t missed any solder connections to the coil nor shorted any adjacent pads out when soldering the coil. Be warned: the pads are very close together and you will need a fine soldering iron, a steady hand and (preferably) a strong magnifying glass and light to work under. Once checked and assembled according to the step-by-step instructions overleaf, it’s time to turn it on and see if it works. Hey, just kidding: there’s no switch to turn on because there’s no power! That’s why it’s called a “passive” antenna. It’s easiest to check without connecting the antenna to a radio. Simply place the radio on the metal box at right angles to the coil. Tune a radio station towards the bottom of the band – a distant one if you can find one. Rotate the antenna tuning knob and at one particular point you should find a significant increase in output from the transistor radio. Leaving the knob in this position, rotate the entire antenna/radio until you find maximum performance. Just as a point of interest, your transistor radio should now be end-on to the radio station – so you know its direction one way or the other! Repeat this for a station at the top end of the band. The peak will obviously be in a different position on the tuning capacitor but it should nevertheless be there. Directly connecting a radio For most people, using the antenna as described above will be more than satisfactory. But if you want to experiment with really pulling in those longdistance stations or separating adjacent ones, you may want to try connecting the antenna to your radio electrically. Or for instance, you may have a metal caravan which effectively blocks radio signals – placing the loop antenna outside might be the only practical approach. Note that this can only be done if your radio has an antenna and earth connection – you could try wrapping a piece of bare wire around the whip antenna but the results are seldom anywhere near as good. In fact, you might find the results are disappointing anyway – it has a lot to do with the impedance of the antenna circuit of the radio and yours might not be a good match. If you want to try this, simply connect a suitable plug (or plugs, depending on the radio connections) to the loop antenna socket and plug in. SC siliconchip.com.au LASERS **WARNING: Only qualified persons should use these components as the dangers of high voltage and high intensity laser energy both apply!!! Death and blindness are both potential dangers if used and handled or installed incorrectly. LS1 (NEW) 40mW+ GREEN LASER HEADS: These heads are supplied with a small matching switched mode power supply module: PCB assembly only. The power supply module is powered from 240Vac, 90-240V / 50-60Hz input. Dimensions: laser 34 x 34 x 80mm; 240vAC power supply module 95 x 52mm. Weight: 220g. $270 LS2 (NEW) 40mW+ RED LASER HEADS: Supplied with a small switched mode power supply (mains wiring required). Input voltage: 100240VAC / 50-60Hz. Output 5VDC / 500mA. Wavelength 635nm - 650nm. Dimensions: 21mm (DIA) x 56mm (L).** $200 LS3 (NEW)BLUE laser diode 20mW: $1300 FLY1 LS2 LASER LS1 FLY1 (NEW) laser light show: LDS1 (NEW) 2 colour laser light show: This professional quality light show features: Solid Uses 2 lasers, red and green...$640 state laser diode, and emits a powerful 30mW at a LDS2 (NEW) 3 colour laser light show: wavelength of 532nm, emerald green(DPSS). It is Uses 2 lasers and mixes the 2 for the third housed in a quality built housing with mounting colour...$700 bracket Cooling: air cooling, Power supply: 240Vac (Some 240VAC mains wiring may be required), Output: 30mW, Control: sound / autoplay, dimensions: 340 X 116 X 119mm, Weight: 3.5Kg. ..$380 POWERFUL DC MOTORS / GENERATORS: SC250G (NEW) 250W DC GEARED MOTOR: 200W & 100W motors as used in our scooters. 4 brush, 4 magnet, 16 pole. 11 tooth sprocket to suit a chain pitch around 7mm. Double ball bearing for long life. Mounting bracket with 4 treaded holes 6mm X 1mm (M6) 100mm Dia. x 80mm L (+ shaft) Shaft: 27mm x 8mm (8mm x 1.25mm. (M8) 2kg. 200W 24VDC, 11.0A, 2750 RPM, $30 (SC200) 300W 24VDC, 16.4A, 2650 RPM, $36 (SC300) CFL1 (NEW) 10W COMPACT FLUORESCENT LAMP: Crompton brand, pn 17347. In original packaging. 220240 Volts, 10 Watts, Edison screw base, 5000°K (white), Up to 6000 hrs, Double PLC. Dim. 44mm x 137mm. 1x 10W LAMP: (CFL1) $3 6x 10W LAMP: (CFL1PK) $12.50 Special!!! One CFL Inverter Kit + 4 CFL1 for only $30 NEW 250W DC geared motors: Can be used to drive electric bicycles etc. Specifications: 250W / 24V, No load RPM: 400, With Load: RPM 320, Torque: 7.46, Chain: 12.7, Sprocket: Z9. These motors would be illegal to attach to a bicycle in Australia, as the legal limit is 200W, although the voltage could be limited to reduce the motors output to the legal 200W. Measures 110mm Dia. x 115mm L (+shaft). Shaft 20mm x 8mm. $79 (NEW) 100W DC MOTOR: $22 (SC100) See throttles on our website SPEED CONTROLLERS TO SUIT FROM $14 PB12 (NEW) 12V / 12AH GELL CELL BATTERY: $35 (NEW) 240Vac - 12V / 24V CHARGERS: 12VDC: (SCC12) $17 24VDC: (SCC24) $17 CRYSTAL LOCKED STEREO FM TRANSMITTER KIT: Based on a small pre-assembled FM Transmitter module that uses 1 of 6 different frequencies. Frequencies are selected by a pushbutton & range from 106.7MHz 107.7MHz. With variable gain it can accept microphone or line level audio signal levels. Simple to build as the module only needs to be wired to a larger PCB which has the audio preamplifier circuitry...Audio response: 20Hz15KHz, Channel separation: 40dB, Total Harmonic Distortion: 0.1%, Pre Emphasis: 50uS, Supply voltage range: 3-12VDC, 30mA<at>9V. Includes PCB, transmitter module, two unidirectional electret microphones and all on-board components. K222. $29 EW N KIT STEREO FM TRANSMITTER MODULE: Frequency range: 106.7MHz to 107.7MHz. Specifications: Audio response: 20Hz15KHz, Channel separation: 40dB, Total Harmonic Distortion: 0.1%, Pre Emphasis: 50uS, DC supply voltage range: 3-12V, Supply Current: 30mA <at> 9V. Dimensions: 32mm x 45mm x 16mm. (FMOD1) $22 NEW 400W WIND GENERATOR: This is a very efficient machine and is designed to run maintenance free even in marine environments. Precision injection molded blades. Consistent aerodynamic outline and mass distribution guarantees the rotors operate at nearly no noise and minimal vibration. Very low start-up/cut-in wind speed, high wind energy coefficient. Designed to prevent blades from feathering. High quality permanent magnet design. Winding and axle are designed to reduce start-up torque, allowing unit to generate at very low wind speeds. High quality aluminum casted body, ensures efficient cooling and is aesthetically pleasing. Designed to operate under severe conditions. Rotor diameter 1.4m, Start up wind speed 2.4m.s-1, Cut-in wind speed 3.0m.s-1, Rated wind speed 12.5 m.s-1, Turbine Rated output 400W,AC12V, Survival wind speed 60 m.s-1 NOTE: There is no mast included in the kit. (WG2) $1050 Mast kit special: Our 4.5M 3 section mast comes with steel guy wires, turnbuckles, ground anchors, nuts and bolts.....all the hardware you will need. $120. NOTE: If used with our new 400W Wind Generator you will need to make a suitable adaptor as the pipe size is not the same. NOW ON SALE FOR ONLY $599 (NEW) 200W WIND GENERATOR: These are serious three phase 200W wind generators with blades spanning 2.2M. They are designed to start operating in low air speeds (around 11kph) while being robust enough to withstand strong gales. These generators are rated at 200W <at> 25kph with a maximum of 250W, output voltages 12V or 24V. Our optional new charger will enable you to charge banks of batteries. Each generator is supplied with mounting plate, three blades, tailfin, nosecone, heavy duty cable, stainless steel guy wires, turnbuckles, ground anchors, nuts and bolts.....all the hardware you will need to build your own wind generator. Also included is a three phase rectifier unit with voltage and amperage metering. These wind generators come in two boxes: Box 1 is 45kg (720 x 440 x 230mm), Box 2 is 27.5kg (1540 x 220 x 110mm). For more information and instructions see our web site. HL1 (NEW) 12V / 50W HALOGEN DICHROIC LAMP: In original packaging. 12 Volts, 50W, 60° beam, Std MR16 glass face, 3000°K (colour temp.), 3500 hours (ave. life). 50mm Dia. x 38mm. 1x 50W HALOGEN DICHROIC LAMP: (HL1) $2.50.... 10x 50W HALOGEN DICHROIC LAMP: (HL1PK) $16 For more info on these and other lasers check out our web site. K K BP PAC 1 1 K1 AIN RG BA CFL2 (NEW) 17W COMPACT FLUORESCENT LAMP: Crompton brand, pn 17408. In original packaging. 220240 Volts, 17 Watts, Edison screw base, 5000°K (white), Up to 6000 hours, Double PLC. Dimensions: 44mm x 165mm. Suitable for use in indoor and outdoor fittings. 1x17W LAMP: (CFL2) $4... 6x17W LAMP: (CFL2PK) $18 CFL3 (NEW) 10W COMPACT FLUORESCENT LAMP: Crompton brand, pn 17348. In original packaging. 220240 Volts, 10 Watts, Bayonet base, 2700°K (warm white), Up to 6000 hrs, Double PLC. Dim.: 44mm x 137mm. 1x10W lamp:(CFL3) $3.50...6x10W lamp:(CFL3PK) $15 ELECTRIC BIKES These fantastic bikes can be ridden under electric power, peddle power or both at once and can be folded in half to transport or store. Features include inflatable tyres. front and rear wheel brakes, lights and more. Motor power: 200W Max speed: 20km/h Max load capacity: 100kg Charging period: 6 - 8 hours Distance: 15km Battery capacity: 12V/12Ah x 2 Weigh: 27kg (SC4) Size: 1130 x 390 x 1000mm Brake: hand brake, rear wheel drum brake. Battery capacity: 12AH, 24V. Battery charger: 240V Motor power: 200W. Charging period: 4-5 hours. Speed: 20km/h. Range: 15km. Wheels: inflatable. Frame: painted steel. Weight: 21kg. Maximum load: 100kg. Forget waiting for trains and busses that don't come, the regulations on the NSW RTA website indicate that they can be ridden under the same rules as a bicycle. Come complete with batteries, lights and charger. $300 (SC3) 0 0 $3 NEW E-BIKES www.oatleyelectronics.com Suppliers of kits and surplus electronics to hobbyists, experimenters, industry & professionals. Orders: Ph ( 02 ) 9584 3563, Fax 9584 3561, sales<at>oatleyelectronics.com, PO Box 89 Oatley NSW 2223 OR www.oatleye.com major credit cards accepted, Post & Pack typically $7 Prices subject to change without notice ACN 068 740 081 ABN18068 740 081 SC_MAR_05 The Jaycar “UV Anti-bacterial Cleaner” kills germs on toothbrushes and shavers and with a small modification can also erase EPROMs. A 1000mF capacitor is connected in parallel with the onboard 220mF capacitor, extending tube run time from a few minutes per session to over 15 minutes. Due to space restrictions, the capacitor is connected to the PC board with flying leads, which are fashioned from light-duty hook-up wire. It can then be held in place with hot melt glue or non-acetic silicone sealant. A cheap UV EPROM eraser A recent gimmick in toothbrush holders proves to be just the ticket for erasing EPROM-based ICs. One additional capacitor and five minutes of work are all that’s required to perform the transformation . . . and you can still use it to sterilise your toothbrush! By BARRY HUBBLE Not too long ago, enthusiasts developing microprocessor-based projects needed access to an ultra-violet (UV) eraser. Unlike current technology devices that can be electrically erased in seconds without even removing them from circuit, older EPROM-based devices have to be exposed to ultra-violet 80  Silicon Chip light to erase their contents. With the advent of electrically erasable memories (EEPROMs), the requirement for a UV eraser has gone by the wayside and it is unlikely that most hobbyists will have one in their kit. However, if you need to modify or repair older equipment that uses EPROMS or want to dabble with any of the microcontrollers that use EPROMbased program memory (such as the PIC16C745/65), then an eraser is still a “must have” item. Dedicated UV erasers are available but at around $300 or more, they would be considered too expensive by most experimenters. Even homebuilt units could prove expensive with tubes costing around $70. Of course, exposure to sunlight for a week or so may erase the chip but don’t hold your breath! A cost-effective solution lies in the Jaycar GH1507 toothbrush holder ($24.95). In its intended use, the UV light from the fluorescent tube in this product kills germs in your toothbrushes and shavers. As luck would siliconchip.com.au Tektronix TPS2000 The New Isolated Channel Battery Operated Scope. Here’s a close-up of the rear of the board showing the two connection points. In this example, the black (bottom) wire goes to the negative capacitor terminal. have it, the light spectrum used for germ eradication also works well for erasing EPROMs. Modifications Whenever the door of the toothbrush holder is closed, it closes a switch, turning on the tube and starting a timer. After a few minutes, the tube is automatically switched off. All that’s required is a modification to the timing circuit to extend the operating time of the tube to something more suitable for EPROM erasure. In its simplest form, the modification consists of adding a 1000mF capacitor in parallel with the existing 220mF capacitor in the timing circuit. This larger total capacitance gives an exposure time of about 15-20 minutes. I have erased four chips at a time with this exposure and have encountered no problems. However, due to the spread of the lamp specifications (0.75 - 1.5mW/cm2), it may be necessary to alter the value of capacitance by trial and error to achieve reliable erasure. To modify the unit, carefully remove the rear cover and identify the 220mF timing capacitor (the largest The existing toothbrush rack is easily removed, allowing up to four EPROMs to be erased at a time. Do you face these Power Measurement Challenges? • Make multi-channel floating measurements • Measure current and voltage distortion and their spectral content • Measure harmonics, instantaneous power, power factor, switching loss to characterise power electronics circuitry • Measure 3-phase currents & voltages • Validate compliance to regulatory standards • Work in an environment without AC Power • Document and Save your measurement results For more information about the TPS2000 family... Talk to NewTek Instruments: Ph: 02 9888 0100 email: info<at>newtekinstruments.com NewTek Instruments Pty Ltd - Sydney - Melbourne www.newtekinstruments.com siliconchip.com.au March 2005  81 Fig.1: a simple IC carrier can be made up from a piece of scrap plastic and some wooden dowels if the unit is to be wall-mounted. You will also need to affix a strip of conductive (anti-static) foam to the opposite side of the plastic to hold the EPROMs in place – see photos below. one). Solder a 1000mF 25V electrolytic capacitor in parallel with this capacitor, ensuring that the correct polarity is observed. Due to lack of space to add the capacitor directly, it should be attached with flying leads and secured with hot melt glue or similar in a position where it doesn’t foul the case. Before screwing on the cover, double check the polarity! Warning: never operate the unit in a disassembled condition or without the plastic door fully closed. The UV rays produced by this type of tube could damage your eyesight! Scottish special? With a little planning, the cost of this project may well be less than a dollar (for the capacitor). How? Well, consider the possibilities were you to give your spouse or friend a toothbrush holder for his/her birthday. Then using our special IC carrier, you can substitute your EPROMs for the usual line-up of toothbrushes when he or she is out mowing the lawn! Perfect! All jokes aside, the unit can easily do both jobs with a couple of simple additions. First, a switch can be inserted in series with the 1000mF capacitor, allowing it to be switched out of circuit for toothbrush cleaning duty. This helps to maximise battery life. Second, a clip-in IC carrier can be installed to allow the unit to operate in its normal position (on a wall). In this case, the chips must be aligned length-ways on the carrier to prevent fouling the toothbrush rack. The carrier can be fashioned out of scrap materials and is held in place by the toothbrush rack. I used a piece of 2.5mm thick plastic from a jiffy box cut to the dimensions shown, with some 9mm dowel off-cuts held in place by 4g x 12mm countersunk screws. A piece of conductive foam is then glued to the face. Power If used frequently, you may wish to dispense with the batteries and power the unit from a 9V DC plugpack. We found that maximum light output occurs at about 8.5V input, so if using a multi-voltage plugpack, try one of the lower settings. We found that the “6V” position on our 1A plugpack produced 9.2V when supplying the modest (110mA) current demands of the holder. A 1N4004 diode is series with the supply brought this back to the desired 8.5V. SC ABOVE: the EPROMs to be erased are attached to the holder simply by pushing them into the conductive foam. RIGHT: the IC holder is then clipped into place in the toothbrush holder with the EPROMs facing down, ready for erasing. Note that the lid must be closed for the unit to operate. 82  Silicon Chip siliconchip.com.au BUILD YOURSELF A WINDMILL GENERATOR Part 4: the nuts and bolts . . . by Glenn Littleford* In our final article of the series, we look at a couple of propeller options, the mast and further refinements of the alternator. This set of tim ber blades w ere carved by Dennis La th and they are am. Length is 1150mm performing w ell on the F&P windmil l. reduce visual They’re painted blue to impact. siliconchip.com.au March 2005  83 T he propeller is the engine of the windmill, taking the power of the wind and converting it into rotary force to drive the alternator. It gets its power from the wind by effectively changing the wind direction and slowing the wind down as it passes through the propeller. The air behind the windmill has lost most of its forward direction and is instead “swirling” in a spiral, until it regains its forward direction some distance downstream. There is a lot of science and maths involved in this process and I’ll only touch on the basics here – you could write a book on the subject and still not cover everything. Fig.2: a blade can be thought of as a series of “stations”. Note the twist in this blade. The blades Each blade has a flat or concave front surface and a curved rear surface. As the wind passes over the blade it provides Lift, driving the blade forward. Our blade has an angle of attack, calculated to provide the most lift without stalling and is usually around 5-10°. So if we know the blade speed, angle of attack and wind speed we can calculate the best overall angle for our blade to provide the best lift, as well as the chord, or width, of the blade (see Fig.1). We also need to allow for the fact that the blades tips are travelling much faster than the blade root (the point closest to the center), so the tips must have a different angle with respect to the blade root. We call this the twist of the blade. The blade angles are calculated at set points along the blade, called “sta- The propeller blades need to extract as much energy from the wind as possible and provide as must rotational speed as possible. Propellers used in power generation are designed to rotate faster than the wind speed. This is called the TSR, or Tip Speed Ratio. A propeller with a TSR of five means the tips of the propeller are travelling at five times the wind speed, so if the wind speed is 25km/h, the tips are travelling at 125km/h. A good TSR for power generation is between four and seven. A TSR of over eight is achievable but at these speeds the tip velocity is so high that blade wear and noise become a serious problem. Modern blades are designed like aerofoils and need to factor in angle of attack, lift, drag and stalling. Fig.1: modern windmill blades are shaped like the wings of an aircraft and use the same principle of operation. 84  Silicon Chip tions” (see Fig 2). On a 1m long blade you might have 10 stations at 100mm intervals so we need to calculate the angle for each station. Fortunately there are free calculators available on the internet that do all the maths for us – we just type in the basic figures and the calculator will give us the best angles and chord widths for each station. Making it with wood The windmill kit described last month includes an adapter plate to suit a set of timber blades, plus an adapter to allow you to fit commercially available blades. The timber blade adapter was designed to suit blades carved from 140mm wide by 45mm thick timber planks, a common size in treated pine. Why use timber? Carved timber blades can offer excellent performance, as we can achieve a near perfect blade profile and have good strength ( trees are very good at bending in the wind without breaking ). But there is a catch: carving timber blades is a very time consuming process, and you need patience and wood working skills to produce a good set of blades (The first blade is easiest, it’s getting the other two exactly the same as the first that’s hard). If you have the time then I would recommend making a set of timber blades, as their performance is exceptional. But if you are like me and couldn’t cut a straight line if you life depended on it, then factory-made blades are another option. You can purchase high quality extruded plastic blades for about $35 each. The adapter in the siliconchip.com.au of PVC is a bit of an unknown. UV light will weaken PVC and it could shatter, sending sharp splinters in all directions, so a safe operating life of two years or less is expected. Currently experiments are been carried out by windmill hobbyists in UV-protective paints and blade mounting, so time will tell if PVC is a viable alternative to timber as a material for home-made blades. Balancing PVC is another windmill blade option, but the long term reliability is yet unknown and there is the fear of them shattering under load. windmill kit will allow you to fit three or six blades, depending on your own needs and location – six blades for low wind areas and three for high wind or costal windmill sites. At the end of the this article are a few links to websites about carving timber blades and sources for factory made blades. There has been some development in using large-diameter PVC pipe as blade material. By cutting a PVC pipe lengthways and reshaping the leading and trailing edge with a file, you can achieve a near perfect blade profile, and the process is so simple you could make a complete set of blades in a few hours. You would need some large diameter (250mm), 10mm wall thickness pipe. A concern is that the durability Once you have made your blades and mounted them on your windmill you will need to balance them. I can not stress how important balancing is. An unbalanced blade will vibrate at high speed and cause bearing failure or worse, blade breakage. At low speed an unbalanced blade will cause the windmill tower to wobble and strain guy wire supports. Balancing is best done in a windfree workshop with the windmill mounted level, as it would be on top of the mast. To check the balance of your propeller, check for a heavy blade; the blade that always wants to turn down. Add weight to the light-side blade/s until there is no noticeable heavy blade. Once done, give the blade several gentle spins and again see if there is a heavy blade. Add weight to the light sides until balance is best. Weight can be added by drilling and adding lead into the blade tips, the lead glued in place with 24-hour epoxy. To test if the weight is correct The windmill kit includes these adjustable plates, used to get the best propeller balance possible. before drilling, sticky-tape the weights to the blade tips until you have the correct balance, then permanently fit the weights. Make sure the weights are properly glued in - at high speed there will be a lot of centrifugal force on the weights and you don’t want them coming out. The windmill kit described last month includes a set of adjustable weights that are secured to the blades with the boltholes at the blade roots. The weights have slots that make fine adjustment easy. Decogging When you rotate the alternator by hand you will notice a cogging action, or a stiffness in rotation at certain points. This is caused by the interaction of the magnets and the stator Fig.3: decogging involves rounding off the stator poles to make the windmill easier to start in light winds. Far left is the standard stator with square ends, creating a stiff magnetic resistance to overcome. Rounding off the stator, as shown alongside, sacrifices some power but reduces cogging. The photo at right shows a decogged motor. siliconchip.com.au March 2005  85 poles. This can make the windmill hard to start in light winds, as the propeller needs to push the alternator past the first cog. Once started, cogging has little effect on the windmill performance - and in fact the windmill can continue to operate in much slower winds than was needed to get it started. If you live in a high wind area, the cogging effect is not a problem. But in a low wind area, your windmill may spend most of the time just sitting there, doing nothing. You could argue that if there is not enough wind to get the windmill started, then there is not really enough wind to generate any useful power anyway so it’s better to have the windmill stationary to save on wear and tear. But if you do live in a low wind area and want to extract as much power as possible, even if it’s only an amp or so, you might want to consider de-cogging. You can modify the F&P armature to reduce cogging, at the expense of a small amount of output power. Decogging involves reshaping the stator poles with a power file (or hand file if you have the time and strength). From the factory the poles have a square edge and are spaced about 0.5mm from the magnets as they rotate past. This square corner gives a sharp rise in magnet flux through the pole producing more power but also increases cogging. If we round off the corners we introduce the magnetic Folding tower flux slowly into the pole and reduce cogging (Fig 3). But as I said before, this will also reduce output power slightly. While cogging can’t be eliminated completely, we can reduce it to a point where the windmill will start in lighter winds. Another way to reduce cogging is to space the magnet hub out from the stator. You can try this by un-doing the plastic hub retaining nut, effectively sliding the hub off the stator. A more permanent solution would be to fit spacer washers onto the drive shaft before fitting the magnet hub. Again performance is lost, so you need to find a compromise. The Mast Its not much good having a windmill unless you can mount it in on something – the mast. As a rule, the higher, the better. You want to get the windmill up into a clean breeze without any turbulence from trees or buildings. While a 20m mast would be great, it’s just not practical for most of us. We do need to consider two things, maintenance and safety. You will need to get the windmill down from time to time to do maintenance and modification, especially in the early days while you are experimenting. Once you have the windmill sorted and making power, you would only need to take it down ever year or so to apply a little oil, check connections, and remove bugs and frogs. Fig.4: two common mast types are folding towers and tilt towers. Each have their advantages but in all cases, use as many guy wires as practical. Tilt tower 86  Silicon Chip siliconchip.com.au Yeah, frogs! Up here in the tropics I had little green tree frogs climb the mast and crawl into the stator at night, only to get centrifuged the next day when the wind picked up. A little grease smeared around the base of the mast put a stop to that. The other consideration is safety. In good winds the tips of your propeller could be doing over 200km/h and should be considered lethal. Your mast should at LEAST be high enough so it’s not possible for anyone to reach the propeller blade from ground level (even jump up and reach), plus a safety margin – say another metre or so. Other things can and do go wrong: blades can come off and towers can fall over. My first tower fell over after days of heavy rain had soaked the ground around the guy wire supports and then a storm pulled one guy wire support (a star picket embedded in concrete) right out of the ground. So you want to make sure your windmill is placed in a position where such a failure could not do any harm to people or property. As a general rule most towers require council approval and such approval is rarely given if your tower could fall onto your next-door-neighbour’s property. I highly recommend you talk to an structural engineer when designing your windmill mast. Consideration will need to be made of soil type, tower height, weight (about 25kg for a completed windmill) and wind loading, based on the diameter of the windmill blade. I use a folding mast for my own windmill. The mast pivots in the middle and I use a small hand winch to raise or lower the windmill. It takes about three minutes and the design means I can work on the windmill without any assistance. The mast pole is 70mm diameter 5mm wall galvanised pipe, and is 7m high when upright. The base is bolted to a buried concrete block 500mm round x 500mm deep. There are three 8mm guy wires, each attached to concrete blocks 300mm round by 700mm deep. So far this new mast has performed well and survived several storms with no problems. For higher masts you would need to look at a gin bar setup and use more guy wires. The more guy, wires the siliconchip.com.au better – they stop mast wobble and give you peace of mind (see Fig 4). Some Useful Links . . . Battery Charger Hugh Picket at www.scoraigwind. co.uk has detailed instructions on windmill building and in particular timber blade design and carving. Once your windmill is up and going you need some way to regulate the output. Most windmills are used for charging battery banks, so a charge controller must be able to switch the windmill over to a load once the batteries are fully charged or battery damage is likely. A commercial controller available is the Plasmatronic range of solar/wind charge controllers, and feature programmable switch over voltages and logging. Or you could build your own. My own charger is based on a PICAXE chip and uses power mosfets to handle all the heavy current switching. The design is a work in progress but the circuit diagram and program listing is available on my web site. (Also see the note below). I have a couple of 12V car batteries wired in parallel as storage. The system powers a string of garden lights modified to take 5W 12V light bulbs, a 50W 12V bed side lamp and a DC water pressure pump. I also have a small 300W inverter on standby to power the TV when the power goes out. Shutting down the windmill. The windmill kit described last month includes a furling system that will turn the windmill out of the wind safely if the wind speed or alternator load are excessive. But if you’re expecting a storm, or plan to go away for a few days it’s always a good idea to shut down the windmill. Once a windmill is shut down the propeller is stopped or only spinning slowly and therefore presents less area to the wind. Only when a propeller is at operating speed will it reach its maximum wind load and exert the maximum force against the tower (a stationary propeller has a relatively small wind loading). We can shut down the windmill in two ways. If you have a rope attached to the tail you can pull the windmill out of the wind and tie the rope to one of the guy wire anchors. Another option is to short out the windmill by connecting the output leads together. This will usually slow the windmill down to a safe speed unless the wind speed is too high, in which case the windmill will con- Michael at www.ecoinn.co.nz has been using F&P motors as generators for many years and sells F&P parts, water wheels and complete windmills using F&P motors. He also sells high quality blade sets suited to our windmill kit. www.otherpower.com has a collection of windmills made from car parts and scrap materials. OtherPower also hosts the FieldLines message board, a great place to share idea’s and ask questions. Plus my own web site at www.thebackshed.com has more information on the F&P windmill, as well as other windmill creations and ideas. tinue to run and possibly burn out the stator. In finishing, there has been a great deal of interest in home made windmills in the last few years and recently in using the F&P Smartdrive motor as an alternator. Windmills offer a very cheap source of power compared to solar, You can build a 300W windmill for less than $300 with a bit of workshop activity and scrounging around – that’s $1 per watt compared to solar cells at close to $10 per watt. And there is a lot of satisfaction is generating your own power from something you built yourself. On the internet you can find a wealth of knowledge on home made windmills. I’ve included some links which you should find useful but there are a whole lot more on the ’net. SC COMING NEXT MONTH While this practical Windmill series from Glenn Littleford has now concluded, next month we plan to bring you a Wind Turbine Regulator and Dummy Load, developed independently by Oatley Electronics. This design will suit virtually all of the wind generation systems in use today as well as many hydro-electric, solar and other “alternate” energy sources. March 2005  87 Salvage It! BY JULIAN EDGAR A $10 lathe & drill press tachometer In essence, this tacho is a simple frequency-to-voltage converter driving a moving coil meter. The standard adjustment pot is shown at top right. Want to know the chuck speed of a lathe or drill press? A car tachometer can easily be adapted to do the job for less than 10 dollars. A read-out of chuck speed on variable-speed drill presses and lathes can be very useful. That particularly applies if you use an electronic speed controller but even if you have to swap gears or pulleys, it’s still good to have a display showing the tool’s rotational speed. In fact, wouldn’t it be good if you could have a big dial displaying revs per minute? Hmm, cars have one of those – it’s called a “tachometer”. And all modern tachos are driven by a simple pulse input, so it’s quite easy to adapt one to do the job. It’s easy and cheap to make a tachometer that measures the rotational speed of your drill press or lathe. The project uses just a few low-cost components and a re-scaled tachometer from a car. 88  Silicon Chip The components To make this speed display you’ll siliconchip.com.au need to scrounge a tacho from a car. When sourcing many secondhand parts, you don’t want to go along to a wrecking yard and ask for the tacho from a specific model – not unless you want to pay top dollar, anyway. No, what you want is an orphan that’s going cheap or perhaps it’s part of a dash display that’s been discarded because the faceplate is scratched. The Australian-built Nissan tacho used to make this display was sourced from the shop at the local tip. In fact, I got the whole instrument panel for just a few dollars. My guess is that it is from a mid-80s Australian-built Nissan Skyline or Pintara but that doesn’t really matter. In addition to the tachometer, you’ll also need a 12V DC plugpack, a reed switch (eg, from the speedo of the same instrument panel), a small magnet, a 10kW trimpot, a 33kW resistor, a 1000mF capacitor and a box to mount it all in. To make a new scale, you’ll need a PC, scanner and printer. By the way, many older Nissans use reed switches to transmit road speed from the mechanically driven speedo to the ECU. However, if you don’t get a reed switch with the speedo, it can be picked up quite cheaply from electronics stores. Building it Fig.1 shows how it all goes together. A reed switch is briefly closed each time a magnet mounted on the driven pulley passes by. This reed switch is fed with a nominal +5V at one end, derived from potentiometer VR1 which is across the +12V supply. Therefore, each time the reed switch Fig.1: the drill press tacho uses a tachometer that’s been scrounged from a car. As shown, a reed switch is fed with +5V DC, derived from trimpot VR1 which is across the 12V plugpack supply. The reed switch briefly closes each time a magnet attached to the machine tool’s output shaft passes close by and feeds an input pulse to the tacho’s input terminal. The 33kW pulldown resistor ensures that the signal input is low when the reed switch is open, while a 1000mF capacitor smooths the signal that’s fed to the meter. closes, a +5V pulse is fed to the tacho’s signal input. Conversely, when the reed switch opens, the tacho’s input is pulled to ground by a 33kW resistor. Note that the tacho assembly shown here has a separate PC board for the electronics, which is actually a frequency-to-voltage converter. This particular one uses an LM2917N as The reed switch was salvaged from an old film processor at the local tip. Here it can be seen mounted directly above the output pulley of the drill press. siliconchip.com.au the frequency-to-voltage converter chip and the datasheets for this are available on the web. As calibrated from the factory, it’s likely that the speed range will be too high for the new application – there aren’t many cases where you want the lathe or drill press doing 8000 RPM! This means two things: first, The reed switch is triggered by this magnetic washer which is glued to the pulley. This washer was extracted from a salvaged stepper motor. March 2005  89 Here’s the original instrument panel and an early draft of the scanned and rescaled drill press tacho scale. It’s printed out 1:1 and so is a perfect size match for the original instrument. a small “washer-shaped” magnet taken from the middle of a salvaged stepper motor. Once the magnet is installed, wire up the rest of the circuit as shown in Fig.1. Trimpot VR1 should then be adjusted to provide a nominal +5V to the reed switch. Don’t forget to install the pull-down resistor. The capacitor across the meter’s drive damps the jerky movement that occurs when the input frequency is lower than it would normally be in a car. Note the polarity of the capacitor – you can work out the meter’s polarity by disconnecting it from its drive circuit and applying a low voltage (eg, 1V) to its leads. When it’s connected so that the needle moves in the right direction, take note of the polarity of the supply. Testing the frequency input range of the tacho will have to be altered; and second, a new scale will need to be made for the meter. In our case, the on-board pot gave plenty of adjustment. In fact, with just one input pulse per revolution of the drill-press, the needle could be adjusted for full scale deflection even at the slowest drill press speed. However, we’re getting ahead of ourselves. Tacho connections The tacho should have three connections: +12V, ground and signal (frequency) input. If you buy the tacho with the whole instrument panel intact (the best approach), look very closely at the tracks on the flexible PC board on the back of the panel. In many cases, +12V and ground (earth) will be marked, leaving only the third pin which must then be the signal input. Conversely, if the board isn’t marked, you may need to seek the help of an automotive instrument repairer to get the pin-outs right. Alternatively, you can usually figure it out by tracing the supply connections. Once the wiring connections are sorted, it’s best to do some experimentation. Use good quality glue to hold the magnet in place on the driven pulley or gear and mount the reed switch so that the magnet passes close by it on each rotation of the shaft. We used The revised and modified scale, printed out on orange paper and covered in clear contact. But just who is behind the “JE Instruments” company? 90  Silicon Chip Once you’ve wired up the circuit, start the machine tool and make sure you get at least some needle deflection on the tacho. If you don’t get any, experiment with the value of the pulldown resistor. This is easily done if you use a 10kW pot wired as a variable resistor and adjust it up and down. If there’s still no joy, try increasing the voltage going to the reed switch. Finally, if you still get no needle movement, add a second magnet directly opposite the first so that there are more pulses per revolution. Once the needle is registering something, run the machine at its fastest speed and try adjusting the on-board pot to get full-scale deflection. If you A reed switch from a speedo was initially used but some dummy bent a lead too close to the glass envelope and broke it! Another salvaged component was then used instead – the reed from a float switch. siliconchip.com.au Silicon Chip Binders REAL VALUE AT $14.95 PLUS P & P The rear of the modified assembly. At left is the pot providing the +5V reed switch supply, at top-right is the new smoothing capacitor, and at right is the PC-board from the original tacho. The 33kW pull-down resistor is just visible at far right and connects the signal input to ground. can’t get there with the built-in adjustment, add more magnets to the shaft of the drill-press or lathe. Calibration If you know the fastest and slowest speed of the machine, you can calibrate the scale to those revs – everything in between will then fall into place since the meter response is linear. You can use your PC and a printer to make a new scale. First, scan in the original car tacho scale and use image manipulation software (eg, Photoshop or Paintshop Pro) to alter the numbers and to delete other markings you don’t want. Of course, at this stage you can also add whatever labels are suitable. Finally, print it out at full size and it’s then just a case of sticking it over the original. We used clear adhesive film SC to protect the paper scale. Alternative Calibration Another good way of calibrating the unit is to first use a frequency measuring multimeter to measure the speed of the tool. The meter will measure in Hertz (cycles per second), so to calculate the tool’s rotational speed in RPM, just multiply by 60. Note: this assumes that you have just the one magnet on the output pulley. If the meter jumps around a lot, try temporarily adding small value capacitors in parallel with the reed switch to dampen the bounce that occurs when the switch closes. Alternatively, if you have a scope, it’s ideal for reading the frequency. Rat It Before You Chuck It! Whenever you throw away an old TV (or VCR or washing machine or dishwasher or printer) do you always think that surely there must be some good salvageable components inside? Well, this column is for you! (And it’s also for people without a lot of dough.) Each month we’ll use bits and pieces sourced from discards, sometimes in mini-projects and other times as an ideas smorgasbord. And you can contribute as well. If you have a use for specific parts which can siliconchip.com.au easily be salvaged from goods commonly being thrown away, we’d love to hear from you. Perhaps you use the pressure switch from a washing machine to control a pump. Or maybe you salvage the high-quality bearings from VCR heads. Or perhaps you’ve found how the guts of a cassette player can be easily turned into a metal detector. (Well, we made the last one up but you get the idea . . .) If you have some practical ideas, write in and tell us! 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 12 issues & will look great on your bookshelf. H 80mm internal width H SILICON CHIP logo printed in gold-coloured lettering on spine & cover H Buy five and get them postage free! Price: $A14.95 plus $A10.00 p&p per order. Available only in Aust. Silicon Chip Publications PO Box 139 Collaroy Beach 2097 Or call (02) 9939 3295; or fax (02) 9939 2648 & quote your credit card number. Use this handy form Enclosed is my cheque/money order for $________ or please debit my  Visa    Mastercard Card No: _________________________________ Card Expiry Date ____/____ Signature ________________________ Name ____________________________ Address__________________________ __________________ P/code_______ March 2005  91 PUTTING THE PICAXE TO WORK . . . PICAXE DATA OVER 477MHz UHF CB We’ve used the PICAXE to do a whole range of things since it first came out. Now let’s do something really useful: send digital data over a UHF CB radio. Yes, it’s legal! by Stan Swan T here’s perhaps no finer recent example of remote communications than the Huygen space probe pictures direct from Saturn’s moon Titan. Even at the speed of light, these ultra-weak digital signals took about half an hour to reach Earth, yet were astoundingly clear! Although such data signalling is naturally associated with the computer age, its basics date back well over a century to Morse code and Baudot teletype. Data communication has had a rich history pre-dating even early electrical technology, with smoke signals, flashing mirrors, semaphore flags, marks in the sand, “1 if by land – 2 if by sea”, green go/red stop lights and so on. But back in the 21st century and terra firma, the cheap, licence-free 40-channel UHF CB sets mentioned last month have two channels (22 & 23) reserved for data transmission. Australian/NZ regulations originally specified this data to have a duty cycle of just 3 seconds per hour, which presumably allowed for diverse services to timeshare the two channels, since three parts in 3600 is a very low 92  Silicon Chip siliconchip.com.au ratio indeed. It was probably envisaged that much data would be simplex (one way) as occasional telemetry (measurement at a distance), indicating reservoir levels or telecommand (remote control) irrigation information, open farm gates, etc where changes over an hour would not be too dramatic. However, in light of recent traumatic tsunami sea water level changes this looks far too conservative – in the real world many things may change horrifyingly fast, with the lack of such localised digital-age warning devices in stark contrast to Titan monitoring over a billion kilometres away. Incidentally, www.manuka.orcon. net.nz/cbdata.htm links to data references and ACA UHF CB regulations. Which data protocol? The type of UHF CB data allowed is not specified. So as well as classic RS232 serial techniques (to be covered later), various DIY schemes and local protocols could be organised. Encoding and decoding, often readily addressed now by software, may lead to technical or practical limitations. Communication issues that contend with weak signals, slow speeds, error correction, interference and limited bandwidth arise as well. Hence it may be tempting to send classic human readable Morse code but that’s now officially an obsolete signalling technique and few people can understand it without considerable training. (Please, no correspondence from irate brass pounders!) Consequently, given their ease of generating serial data and assorted audio tones, it’s no contest to use a Picaxe microcontroller approach. For this initial UHF CB data treatment, a 3-lead (Maxim) Dallas Semiconductor DS18B20 temperaturemeasuring device is simply read at regular intervals by a Picaxe 08M using its inbuilt ‘readtemp’ command. The DS18B20 can read temperatures accurate to 0.5°C between -10° and 85° but can handle -55° to +125° with reduced accuracy. This Celsius value is then converted to a simple audio tone sequence relating to temperature, under a scheme where longer tones mean “tens” and shorter tones “units”. With only a brief explanation even a child could decode the temperature, as of course can any listening audience with a UHF CB receiver – no computer siliconchip.com.au IO PINS (CHANNELS) (TO PC CON2 DB9 SERIAL PORT) CHANNEL 0: PROG OR OUT CHANNEL 3: IN ONLY 2 4.7kΩ 22k 3 10k 5 1 2 3 IC1 PICAXE-08M 4 LEDS 7 0 6 1 5 2 8 3 K A 4 DS18B20 V+ 8 +4.5V (3xAA) 4 1 +V GND DATA SC 2005 PIEZO 100nF WHITE LED λ DATA DS18B20 λ LDR TO UHF CB TRANSCEIVER MIC SOCKET* 1kΩ GND (* JAYCAR DC-1030 USES 3.5mm STEREO PLUG TIP AND BASE) UHF CB DATA MODULATION While this circuit uses the 08M (as distinct from the earlier 08) connections are pin-for-pin compatible and the vast majority of functions are identical. It’s just that the 08M has more grunt in certain areas! The white LED and LDR provide an isolated means of “keying” the transmitter (ie, turning it on). or software necessary to monitor that heatwave! The temperature is preceded by pleasant attention-getting audible sliding tones (based upon a cat’s greeting in fact!), then long and short tones to suit, similar to radio time signals or PC boot error beeps. As an example, 23°C would sound as long, long, short, short, short with a tropical 31°C long, long, long, short and a cool 4°C as just short, short, short, short. Negative temperatures have a higher “frosty” tone, with zero a drawn out “l-o-n-g”. Your local conditions will readily attune your ear to a sequence (you 3.5mm STEREO PLUG TO UHF CB TRANSCEIVER PLUG BODY won’t be having many subzero values in Darwin!). Calibration, against a known temperature standard, can be made by placing the unit in the fridge, freezer or (for elevated values) a car parked in the hot sun. Extending the leads on the DS18B20 is quite feasible but avoid direct contact of exposed terminals with water, of course – cover them with neutral silicone sealant or heatshrink tubing perhaps if monitoring your home beer fridge, via UHF CB, when at work some kilometres away! Given the range of these CB sets with an external antenna (as detailed PLUG TIP PIEZO 0V 100nF 4.5V PICAXE08M 10kΩ D A 22kΩ 5 3 2 (RS232) 10kΩ 4 3 2 1 0 LDR LED +V DS18B20 K GND D 4.7kΩ +V This layout on proto-breadboard should look pretty familiar to anyone who has been following our PICAXE series (it first started back in 2003!). It’s not exactly the same as the photo opposite – follow this one if there is any confusion. March 2005  93 February 2005 SILICON CHIP), of course the opposite application may appeal – did your public building air conditioning/heating get turned on well before the attendants arrived? Connecting to the CB The Jaycar DC-1030 UHF CB set shown here comes fitted with a single 3.5mm stereo socket. This does multiple duty – internal battery charging as well as external microphone and earphones. Experimentation revealed that external audio could be fed in via the tip end and body of a matching 3.5mm stereo plug but that the transmitter would only be keyed on if a resistance, in parallel across this input, fell below around 1kW. Such a solid state transceiver switching technique is rather in contrast to historic “ker-chunk” relay or big switch action but apparently is becoming the norm on hand-held 2-way radios. The budget Dick Smith D-1793 models, however, use a smaller 2.5mm socket and may need VOX transmitter switching instead. Opto-coupled transmission A neat Picaxe way to provide this resistance is to illuminate, at the right time, a light-dependent resistor, or LDR, with a nearby white LED. A typical LDR has a “dark” resistance of some (sometimes many) megohms, dropping to the low hundreds of Ohms in bright light or sunshine. 94  Silicon Chip An offcut of dark plastic sleeving allows the opto-coupled pair to switch the transmitter when a high signal comes from output 2. A series 1kW resistor dims the LED sufficiently to reduce battery drain while still ensuring reliable switching and the optical isolation helps keep possibly confusing RF from the sensitive Picaxe circuitry. To avoid overdriving the transmitter, audio from the Picaxe output 0 is passed via a series capacitor – 100nF (0.1mF) was found suitable. A local piezo sounder attached to this channel allows the outgoing sounds to be also conveniently heard, and of course the glowing of the white LED indicates that the transmitter is being keyed on. Powering-down the sensor The DS18B20 sensor can normally draw several milliamps, even when not being read. If an extended “sleep” is underway, with attendant microamp level power drain on the Picaxe itself, it’s wasteful to “keep its motor running” by supplying such an extra component. As the 08M has a spare output channel, a technique suggested on the Picaxe forum (www.picaxe.com) is used to greatly reduce current drain. The DS18B20 is itself controlled by Picaxe output 4 which only switches it on just before it needs to be read. No significant sensor warm up time was noted, although a brief settling period was provided in the code. Abundant code space is still available on the 08M and extension for interrupts (to flag an unexpected value), or data logging is feasible. Even a store and forward scheme could be used, so that a whole package of values could be sent at a predetermined interval – akin to checking your mailbox perhaps? Construction It’s recommended once again you make up this circuit on solderless prototyping breadboard, as we’ve used in earlier Picaxe articles. If you’ve made up any previous Picaxe projects on breadboards, wiring this one should be a cinch. Note in the photo we have stuck a tiny label around the DS18B20, to avoid confusion with deceptively look-alike BC547 transistors! We’ll be using almost exactly the same layout for an extended UHF CB data approach employing faster machine readable encoding. Naturally more specialised machine decoding will then be needed too – as Morse diehards will testify, human readable data may be slower but it does have some practical benefits! Footnote: Although a well established and highly respected IC, manufacturing problems lead to DS18B20 supplies being globally very erratic in mid 2004. Hopefully this has now sorted itself out, to ensure reliable supplies for this circuit. siliconchip.com.au UHFCBDS listing (also available for download: www.picaxe.orcon.net.nz/uhfcbds.bas) ‘=> uhfcbds.bas <= 477MHz licence free UHF CB & DS18B20 combo- Ver 1.0 Boxing Day 2004 ‘For Silicon Chip Picaxe article (March 2005) via Stan. Swan => s.t.swan<at>massey.ac.nz ‘UHF CB sends audible Ch.22/23 temperature data via Dallas Semi.DS18B20 & Picaxe-08M ‘interfaced (as human readable audio tones) to a Jaycar DC1030 UHF CB 1/2W transceiver. ‘NOTE: ACA/RFS regs.say “UHF CB data Ch.22/23 max. duty cycle just 3 seconds an hour”... ‘Temp range tested from subzero freezer (~-4C) to high 30s C, but OK even higher ~55 C? ‘DS18B20 draws ~9mA,so Ch.4 used to just switch on as needed & thus enhance battery life ‘Many audible ways to pass data of course,but our simple approach suits kids & oldies! ‘Morse involves *#%<at>^! training,while technique here just involves listening & counting ‘Considerable enhancement scope as 08M memory barely half used! Store & forward EEPROM? ‘See David Lincoln’s Vol.2 ‘Expts in Mechatronics’ P.18-25 for number massaging insights ‘Refer circuit layout => www.picaxe.orcon.net.nz/uhfcbds.jpg & program .../uhfcbds.bas ‘ -------------------------------------------------------------------------------------‘b0 = direct Celsius temp value read from 3 lead DS18B20 temperature IC ‘b1 = 10s values (heard as longer pulses ) obtained by integer division ‘b2 = units value (shorter beeps up to 9 in value) by isolating remainder ‘b3 = loop multiplier for 10s- thus 20 C will have 2 longer beeps ‘b4 = loop multipier for units- so 17 C will have 1 long & 7 short beeps ‘b5 = -ve temps subzero correcting factor ‘b6 = -ve temps subzero loop multiplier to give “urgent” beeps ‘--------------------------------------------------------------------------------------tempds: wait 2 ‘transmitter “tail” hold on to avoid click confusion with beeps low 2:low 4 ‘ensure ch.2 LED & ch.4 supply (to DS18B20) are both off sleep 2 ‘master delay -alter to suit (units 2.3 sec)for other intervals high 2: high 4 ‘turn on LED/LDR combo & also DS18B20 wait 1 ‘transmitter & DS18B20 settling time before reading sound 0,(95,3,0,3,100,3,0,3,105,3,0,3,110,3) ‘ warble alert pre data arrival wait 1 ‘1 sec pause to allow listener attention for data readtemp 1,b0 if b0=0 then zero if b0>128 then subzero We have the best value, brightest LEDs available in Australia! Check these out: Luxeon 1, 3 and 5 watt All colours available, with or without attached optics, as low as $10 each Low-cost 1 watt Like the Luxeons, but much lower cost. •Red, amber, green, blue and white: Just $6 each! Lumileds Superflux These are 7.6mm square and can be driven at up to 50mA continuously. •Red and amber: $2 each •Blue, green and cyan: $3 each Asian Superflux Same as above, but much lower cost. •Red and amber: Just 50 cents each! •Blue, green, aqua and white: $1 each. Go to www.ata.org.au or call us on (03)9419 2440. ‘Picaxe 08M (or perhaps 18X) command to read ch.1 DS18B20 ‘test if DS18B20 at zero Celsius (water freezing point) ‘test for DS18B20 sensor subzero correction as b0 values >128 b1= b0/10 ‘divide original b0 temp to get 10s value b2= b0//10 ‘divide original b0 temp so remainder yields units value if b0<10 then units ‘bypass tens sounds if temps below 10 Celsius ‘debug ‘suitable spot to note b0 etc variable values when fine tuning? ‘--------------------------------------------------------------------------------------tens: for b3=1 to b1 sound 0,(100,50,0,50) ‘ longer beeps for 10s. Thus 20 Celsius = 2 long beeps next b3 ‘--------------------------------------------------------------------------------------units: if b2=0 then tempds ‘units nulling factor if temps are exact multiples of 10C for b4=1 to b2 sound 0,(100,5,0,50) ‘shorter beeps for units, so 9 C = 9 short beeps next b4 goto tempds ‘read sensor again ‘--------------------------------------------------------------------------------------zero: sound 0,(100,500) ‘prolonged tone to indicate zero Celsius goto tempds ‘read sensor again ‘--------------------------------------------------------------------------------------subzero: b5=b0-128 ‘correcting factor for DS18B20 when reading subzero for b6=1 to b5 sound 0,(120,5,0,50) ‘more alarming ‘frosty’ beeps,since now below freezing ! next b6 goto tempds ‘read sensor again siliconchip.com.au Want cheap, really bright LEDs? SC March 2005  95 Vintage Radio By RODNEY CHAMPNESS, VK3UG The Astor AJS – an economy universal car radio Designed as an economy model, the Astor AJS car radio used six valves and could be used with both positive and negative earth vehicles. It also employed a vibrator power supply and was an excellent performer. A FRIEND WAS disposing of his collection of old radios and various bits and pieces and “threw” them in my direction. Amongst them was a rather battered old car radio – an Astor AJS. Unfortunately, its front panel escutcheon was broken and I initially had no idea as to how I might fix it. As a result, the set was put to one side until a friend suggested that a product called “Knead It” from Selleys may be suitable for the repair. As it turned out, this was just the shot for remaking the missing section of the escutcheon but more on that Looking quite smart – the old Astor AJS car radio with its repainted cabinet and its fully restored escutcheon. 96  Silicon Chip later. Now I had no excuse for not restoring the old Astor radio. Universal radio The AJS is a 6-valve, universal, vibrator-powered car radio that runs off 12V DC. What do I mean by universal? Well, this set is an economy model and was designed to fit any car of the 50s and 60s by being screwed to the underside of the steel dashboard. It has an integral speaker, no RF stage and can be used with both positive and negative earth vehicles (many English vehicles in particular used positive earth at that time). Sets of this type were a joy to install, taking under half an hour from the time the vehicle arrived in the workshop until it was driven out. I remember fitting car radios with a firm in Adelaide back in the late 1950s and we could fit and adjust a car radio in a Holden FE, complete with a separate speaker behind the dash, in about 20 minutes. A really switched on installer could probably fit one of these AJS models in under 15 minutes. Try that with the latest vehicles! Astor made many different car radio models from the 1930s until about 1970, when imported car radios sank that part of the domestic radio manufacturing industry. Along with other Australian manufacturers, they made many high-performance receivers that could pick up stations over long distances. These sets were often limited only by the effectiveness of the ignition interference suppression and the amount of noise generated by the highvoltage power lines that run alongside many of our roads and streets. Cleaning up As it came to me, the old Astor siliconchip.com.au VALVES AUDIO HI-FI AMATEUR RADIO GUITAR AMPS INDUSTRIAL VINTAGE RADIO We can supply your valve needs, including high voltage capacitors, Hammond transformers, chassis, sockets and valve books. WE BUY, SELL and TRADE SSAE DL size for CATALOGUE This top-chassis view emphasises the compact nature of the unit. Note the vibrator supply components at the top of the photo. receiver was in a rather sorry state. The first step was to give it a thorough clean-up. The case was given a good scrub in warm soapy water, then rinsed in clean water and allowed to dry – I didn’t want it to rust any more than it already had! I then masked the escutcheon area and gave the case several coats of rust inhibiting paint from a spray can. That done, I turned my attention to the broken front panel escutcheon. As had been suggested, I used Selley’s “Knead-It” (available from hardware stores) to make a new piece to replace the missing section. However, I decided that the “Knead It” might also need reinforcing, so I obtained a short length of thin high-tensile wire and ran it along the area where the escutcheon would be. First, a small hole was drilled into one end of the remaining escutcheon. One end of the wire was then placed in the hole and the other end was wedged under the other end of the escutcheon. That done, I then glued (with Araldite) the wire in several spots to the receiver case, along where the escutcheon would normally be. Finally, I got out the “Knead It” and laid it along and around the wire. I initially found it a little difficult to knead but warming up the material makes it more pliable siliconchip.com.au and easier to work. After about half an hour, it had set and using a knife and file, I was able to shape the hardened material to match the profile of the missing section. Once it had fully hardened, I spray-painted the whole escutcheon in the nearest colour available in a spray paint can. ELECTRONIC VALVE & TUBE COMPANY PO Box 487 Drysdale, Vic 3222 76 Bluff Rd, St Leonards, 3223 Tel: (03) 5257 2297; Fax: (03) 5257 1773 Email: evatco<at>pacific.net.au www.evatco.com.au Cleaning the inside With the outside of the set now looking the part, it was time to tackle the chassis. The first step was to draw a diagram of the valve locations, as this information is not marked anywhere on the set. That done, the valves were all removed, cleaned with soapy water, rinsed and stood on their pins to dry. When doing this, you have to be careful not to rub the type numbers off the valves. If you do rub a type number off or damage it, a black fine-pointed marker pen can be used to remark the glass envelope. It might not be as neat as the original marking but a least it will help prevent the valves getting mixed up and possibly plugged into the wrong sockets. For a car radio, this set was remarkably clean. A small paintbrush was used to get rid of loose dust and other debris from the chassis, although an air-compressor can also be used (with care) to do this job. The more “caked-on” muck was removed using a strip of a kitchen scouring pad moistened with kerosene. In this case, some gentle scrubbing got rid of most of the muck and the set with its cleaned valves now looks quite smart. The more awkward spots on the chassis are cleaned by using a pencil or screwdriver to push the scourer back and forth to get the muck off. In this set, the dial scale has become a bit brittle and has yellowed with age. It was cleaned carefully with soapy March 2005  97 Photo Gallery: Genalex Model 610 the set on. The power lead and the fuseholder were in very poor condition. The power lead was replaced with 3mm automotive cable, while the badly corroded fuseholder was replaced with a more modern plastic unit. This new fuseholder was spliced into the line using crimp connectors. I fitted a 5A 3AG fuse although the circuit diagram says to use a 15A fuse. That may be OK for the 6V version but for the 12V version of the receiver, a 5A fuse is perfectly adequate. After all, the set only draws 3.25A on 12V according to the service data. Personally, I like to fit a fuse with a rating that’s not much higher than the maximum operating current. If too high a value is fitted , the set could be virtually on fire before the fuse blows – if it blows at all. Buffer capacitor Manufactured by the British General Electric Company Ltd, Sydney in 1939, the Genalex Model 610 was a dual-wave superheterodyne set that covered both the medium-wave and the 6-18.75MHz shortwave bands. An extra large dial was fitted to the front of the receiver, while the speaker faced upwards, the sound exiting from the top of the receiver. The valves fitted were as follows: 6K8-G frequency changer, 6U7-G IF amplifier, 6G8-G audio amplifier/detector/AVC rectifier, 6V6-G audio output and 5Z4-G rectifier. Photo: Historical Radio Society of Australia, Inc. water and a soft brush and came up reasonably well. What’s more, the printing is all still attached to the scale – a lot better than in some sets where the printing falls off if you just so much as look at it (or so it seems). Before cleaning any dial scale, always test a small area that is hidden by the escutcheon or is of little value, to see how firmly the lettering is attached. The value of a set with a ruined dial is much lower than a similar set with a good dial scale. 98  Silicon Chip Unlike the chassis, the knobs were extremely grotty. They were thoroughly cleaned in a basin with soapy water and a nail brush and came up looking almost like new. However, one knob is a two-section unit and it had broken apart. It was glued together using Araldite and the set was now looking rather spick and span. Parts replacement As is my normal policy, I did all the routine fault-finding before turning Astor car radios with vibrator power supplies had one component that caused considerable trouble and that was the 8.2nF (.0082mF) 2kV paper buffer capacitor across the plates of the rectifier valve. If this capacitor is not replaced, the vibrator may break down after only a few hours of operation. By contrast, some models used 4nF (.004mF) mica buffer capacitors which gave very few problems. More information on vibrator power supplies can be found in the Vintage Radio columns for September and October 2003. In addition, the October and November 2004 columns highlighted the problems that paper capacitors suffer. It’s always a good idea to take a good look at the wiring before replacing any components in car radios, as there are usually lots of parts packed into a relatively small space. As a result, it will usually take you longer to replace components in a car radio than in a normal mantel or console receiver. Lead dress is often important too, otherwise you may not get all the parts in. In addition, the stability of the receiver may be compromised as car radios are high gain receivers and the inputs are not that far away from the outputs. The best advice is don’t take any shortcuts with wiring – instead, rewire it exactly as it was originally. Note that any earths to chassis around the vibrator supply should always be made to the same spot as before. The wiring around the vibrator supply is often critical, otherwise siliconchip.com.au interference (vibrator hash) may be generated which gets back into the antenna and thus into the receiver. However, this isn’t usually a problem as the whole set is within a metallic shield and the antenna is mounted outside the car and connected to the set via a shielded lead. This shielded lead also keeps out vehicle-generated interference (eg, ignition noise). Another feature used to reduce interference into and out of the receiver is the “HASH PLATE”, as seen on the lower left of the circuit. In this receiver, it consists of a metal strip along the side of the chassis, near the vibrator power supply, and is about 80mm long and 12mm wide. In practice, it is mounted between the chassis and another metal plate, with a strip of insulation on either side of it so it does not short to either the chassis or the other earthed plate. The 12V supply comes in at one end of this plate and out the other end. In effect, the two plates form a very low inductance capacitor which helps prevent interference from the car’s electrical system getting into the sensitive RF stages of car radios. It also helps prevent interference from the vibrator circuit going out along the power supply line. Such plates are not used today as more effective filters are now made, such as coaxial capacitors, etc. Finally, I checked all my usual suspect components and found that most were leaky. These were replaced, along with the buffer capacitor mentioned earlier. Basically, those components numbered (5), (20), (24) and (27) were replaced. Powering up By now, all the critical components had been checked and all appeared to be in good working order. Power was then connected and the set switch on. No unpleasant smells or noises came from the receiver and the vibrator was humming away quite happily. This was a bonus, as I had expected that the vibrator might not function as most had only limited lives. In fact, the high-tension (HT) voltage was close to normal, which was very pleasing. The set itself was showing signs of life so I put a screwdriver into the antenna socket and touched the shaft so that I acted as an aerial. The set then pulled in stations quite strongly as I tuned across the band. siliconchip.com.au Fig.1: the circuit uses six valves but unlike many other car radios of the era, has no RF stage. Despite this, the set has very good performance. I checked the front-end alignment and all appeared to be spot on so I left it alone. Similarly, I left the IF alignment alone as the IF transformer adjustments are usually well and truly locked in place with sticky core locking compound. It doesn’t mean that you cannot adjust them but it’s best March 2005  99 This under-chassis view of the old Astor AJS (after restoration) shows the crowded component layout. Care is required when fitting the chassis back in its case. to leave them if you can. In this case, the set’s performance meant that there was no need to align it. However, once the receiver is installed into a vehicle, the antenna circuit coil will need adjustment at around 1400kHz for best performance. In fact, all car radios of this era need this after installation or service. The adjustment control is on the back apron of the receiver, alongside the antenna socket. Reassembly Reinstalling the chassis into the case proved to be quite a task. That’s because the set is crammed into the available space and there is very little clearance between the chassis components and the cabinet. In practice, I had to flex the cabinet so that I could slide the chassis in. Unfortunately, when I tried the set out, the oscillator wasn’t working so there were no signals. I dismantled it again and tried to find out if any components had shorted but couldn’t really find anything wrong. In the end, I moved a few parts around to make sure that the clearances were adequate. The set was working out of the cabinet so I shoe-horned it back in and tried it again. This time, it worked so I had obviously shifted the right item to stop it from shorting. This sort of problem is not uncom100  Silicon Chip mon in tightly-packed units such as car radios. Circuit details The circuit for this receiver is somewhat different to most car radios of the era. That’s because it has no radio frequency (RF) stage. Instead, the received signal feeds straight into the converter – a 12AN7 (or 6AN7 in the 6V version). Note that the 12AN7, 6AN7, 6AE8, 6AJ8, 12AH8 and other miniature valves of the general triode-hexode family are much quieter converters than the more popular 6BE6 and other pentagrid converters. If a 6BE6 had been used in this position, it’s likely that the receiver would have been quite “hissy”, which would have been annoying and would have restricted its ability to pick up weaker stations. Because they have only small antennas, car radios are almost always working with weak signals. I have a number of receivers which use triode-hexode converters as the first amplifying valve in the receiver and many of these are quite good performers on both the broadcast and shortwave bands. I cannot say the same about receivers using a pentagrid converter, although sets using pentagrids are more common than those with triode-hexode converters. The IF amplifier stage in this re- ceiver is also rather unusual, in that it has two valves (V2 and V3) between the two IF transformers. These valves are both 12BA6s (or 6BA6 for 6V) and are resistance-capacitance coupled. In fact, the circuit looks a bit like an audio stage except that the component values are different. It uses a 10kW plate resistor, a 47kW grid resistor and a coupling capacitor of just 50pF. This coupling method is not particularly efficient at intermediate frequencies (IF) such as 455kHz. However, a variant of the normal audio amplifier inter-stage coupling method is used in valve (and transistor) video amplifier circuits which will amplify signals quite effectively to at least 5.5MHz. It appears that Astor wanted more gain than could be obtained using just one 12BA6 but less than that obtained using two valves in a conventional 2-stage IF amplifier. By adjusting the values of the coupling components, the designers were able to tailor the two stages to get the maximum gain possible, consistent with stability and low cost. Delayed AGC The signal detector and AGC diode both have a small delay before they operate. This means that the receiver is slightly muted between stations, as the diode detector has bias on it due to the fact that V4’s cathode is a siliconchip.com.au fraction of a volt positive compared to the detector plate. This delay also provides the delayed AGC. The audio amplifier stages are quite conventional and similar circuits are used in many mantel radios. Back bias is provided for the 12AQ5 by the voltage drop across resistor 48. Negative feedback is provided from the secondary of the speaker transformer to the cathode of V4 via resistors 51 and 52. These two resistors form a voltage divider, so that just the correct amount of negative feedback is applied. The audio top-cut filter/IF signal bypass capacitor (27) is wired from plate to screen, which reduces the voltage across this capacitor. The power supply is a standard vibrator circuit, as used in almost all Astor vibrator car radios. Compared to those used in household vibrator power supplies, the filtering in this set is minimal. To reduce interference from this supply, the antenna is connected via a shielded cable as mentioned previously. In addition, the wiring between various stages within the set has been kept short to minimise pick-up from the supply. A valve rectifier is used to convert the square wave AC from the vibrator into DC. The advantage of having a valve rectifier is that the active power lead from the set can be connected to These are the components that were replaced, including the 12V power lead. either +12V or -12V, depending on whether the car uses positive or negative earthing. Components 18 and 16 are the buffer capacitors. As mentioned earlier, capacitor 18 can be troublesome but capacitor 16 rarely gives trouble as it is not highly stressed. Summary I must admit that I didn’t expect this little Astor receiver to be as good as it really is. Despite being an economy design, it does what it is expected to Brand New From SILICON CHIP do and performs very well. On the debit side, it’s not an easy set to service (like most car radios), as the parts have to be mounted precisely or they won’t fit. As an example, the replacement 8.2nF 2kV buffer capacitor was difficult to fit as the original was physically smaller. It may not be the flashiest set around but I’d certainly give Radio Corporation the thumbs-up for this little set. It’s a set that’s well worthwhile collecting, if only to show just how good an SC economy car radio could be. 160 PAGES 23 CHAPTE RS Mail order prices: Aust: $A22.50 (incl. GST & P&P) Overseas: $A26.00 via airmail From the publishers of Completely NEW projects – the result of two years research & development • Learn how engine management systems work • Build projects to control nitrous, fuel injection and turbo boost systems • Switch devices on and off on the basis of signal frequency, temperature and voltage • Build test instruments to check fuel injector duty cycle, fuel mixture and brake and coolant temperatures Available from selected newsagents Intelligent turbo timer I SBN 095852294 - 4 9 780958 522946 $19.80 (inc GST) NZ $22.00 (inc GST) TURBO BOOST & nitrous fuel controllers How engine management works Or order by phoning (02) 9979 5644 & quoting your credit card number; or fax the details to (02) 9979 6503; or mail your order with cheque or credit card details to Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. siliconchip.com.au March 2005  101 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 Tacho connection for a V8 Falcon I am just wondering how does a tachometer for an XC Falcon 4.9l V8 Cleveland work. I am trying to hook the tacho up from the +ve coil and the -ve battery and it doesn’t seem to be working. Any hints? (A. H., Kingaroy, Qld). • If the tacho requires an ignition coil signal, the connection would be from coil (-) and ground (chassis) rather than coil (+) and ground. This is because the primary coil voltage is developed at the switched end – ie, the coil connection to the points or switching transistor. FM transmitter does not work in stereo I have recently built the Micromitter stereo FM transmitter from the December 2002 issue. It works but not in stereo. Turning VR3 clockwise or anti-clockwise adjusts the output volume but I still can’t adjust it for stereo. Do you know how to get it working in stereo? (M. C. Kilsyth, Vic). • Make sure the frequency set by the four switches (S1-S4) matches that on your receiver. You must accurately tune the receiver to the transmitted frequency. Check that the phase lock loop is operating by measuring the voltage at TP1. Does this stay at a fixed voltage of around 2V that changes if the frequency is adjusted with the switches? If not, check the L1 coil winding. The direction of the winding and height above the PC board must be the same as shown in the photo. Energy meter offset quandary I have recently constructed the Energy Meter (SILICON CHIP, July & August 2004), the kit being purchased from Dick Smith Electronics. I was rewarded with immediate success but noted an interesting effect with the offset calibration adjustment. Firstly, with a charged 9V backup battery installed and with mains power and load disconnected, I adjusted the offset setting (+7, I think) so the display indicated 0.00W. However, when mains power was applied and still with no load connected, the display read +0.21W. Secondly, again with no load connected, I tried zeroing the offset setting (-15) while mains power was applied. This time when mains power was disconnected, the display read -0.21W. I am assuming there must be a small amount of AC leakage when mains power is applied. Is a relatively small no load offset of 0.21W within the expected limits for this circuit? (B. B., vie email). • Having AC mains connected without a load and having no mains connected will give different offset requirements. This is because the mains voltage introduces signal into the IC via the voltage input and current inputs. This was minimised as much as possible with the balanced inputs. However, there will always be some difference. Typically, the Energy Meter will be operated with power applied and the battery backup is only used with blackouts where this is expected to be short compared to when power is on. Multi-picture TV program monitor The commercial TV channels are tending to over-run their evening programs. How about a project that could produce two, four or six sub-screens on a standard TV set with selectable Speed Controller For A Golf Buggy I’ve just built the 20A version of the DC Speed Controller, as described in your June 1997 issue. This was to replace an electric golf buggy controller which had ceased to operate. The unit works well but I can’t get the motor to stop completely. The trimpot supplied varies the speed from close to zero to full speed but full speed occurs at just half travel. Can you suggest a way around this? Also the motor emits a highpitched sound, due (I imagine) to the FETs turning on and off. Is there 102  Silicon Chip any way to filter this out or at least minimise it? (D. R., via email). • To get a more realistic adjustment range in your application, try inserting a 3.3kW resistor in series with the positive side of VR1 – ie, the side that connects to pin 14 of IC1. To get zero speed, try reducing the size of the bottom resistor in the 18kW + 4.7kW divider network connected to “MOTOR-”. We suggest a value of 4.3kW instead of 4.7kW. You may be able to reduce harmonics in the switching circuit and therefore the noise from the motor by placing a small capacitor in parallel with the 4.3kW resistor. Start off with about 68nF and test the operation of the circuit. If speed control becomes erratic, try a smaller value. If the above doesn’t help, try reducing the switching frequency of the TL494 by increasing the value of capacitance on pin 5 from 68nF to 100nF. This may make the noise a little less irritating. It’s unlikely that the noise can be completely eliminated. siliconchip.com.au sound. This could be accessed by either a spare channel or AV input. You could then watch the end of one show while keeping an eye on the start of the next show. It could also be used without sound to now and again glance at all channels at once while reading, etc to see if anything worthwhile is on. (J. O., via email). • That’s an intriguing idea but it would basically mean one TV tuner/ IF strip/video processor and picturein-picture chipset for each channel you wanted to watch. In the capital cities, that means at least five channels and many people would want Pay TV as well, making it very complex and expensive. If you’re that keen to watch TV, maybe you should just get an array of small TV sets, each one permanently tuned to one channel. When one comes up with something interesting, switch to your large screen set. LED ammeter for battery charger I am wanting to fit an ammeter to a car battery charger. I am thinking of a 10 LED readout to 5A. Have you published a circuit for this? Could the 25A car LED ammeter (SILICON CHIP, January 1999) be altered to do this? (G. J., Lara, Vic). • The 25A LED meter can be used in your application without any modification. All you have to do is have it monitor a suitably low resistance value in series with the battery charger. You can then calibrate it to display 5A. Mind you, since it will only ever read positive current (ie, charge), only five LEDs of the display will be involved. If you want to use the 10 LEDs, then you will need to remove the offset trim circuitry involving VR2. Eprom programmer doesn’t work I have assembled the Windowsbased Eprom Programmer (SILICON CHIP, November & December 2002, February 2003) and carried out the voltage and frequency checks. I tested the software to toggle the Load PGM* Pulse Duration LED. That works. Everything is OK but I am unable to get a valid EPROM read or write. I set the read for an ST 27C256 using the preconfigured settings provided. siliconchip.com.au Remote Control Volume Via CD Player I recently purchased a Remote Volume Control kit (SILICON CHIP, June 2002) for my hifi amplifier. Your instructions state that it should work with any Philips-based remote control. I also purchased a suitable multi-item remote, recommended by the kit supplier (Altronics) and the default PC board (with no links) should work with a TV code. The red Ack LED flashes but the potentiometer does not move. Ideally, I want to use the volume buttons on my CD player’s remote control. For this, I need to insert a link between pin 14 and ground (LK2). It is nearly impossible to place a solder bridge across this point, so I decided to fit a small wire link to a point on the ground track. With this link in place, the PC board fails to acknowledge any remote control command, regardless of code. My CD player is a Marantz (formerly part of Philips) so am pretty sure it should work. Can you please suggest anything I could try or may have done wrong? (M. G., via email). • First of all, the Remote Volume All I get on the read is FF on all addresses. I know for a fact that the chip contains information because it is used to operate a machine. What could be wrong with the programmer? (D. C., Christchurch, NZ). • It sounds as if you may have either a faulty solder joint on the programmer board or a faulty chip. Either that, or your PC’s printer port is not allowing the software to read data correctly. We suggest that you try checking the clock frequency test points with a scope, to make sure that the clock circuitry is working correctly. You could also try checking at pin 10 of IC18 (74HC02) to make sure that it pulses low during each read operation. Fuse blowing is a warning I am having a problem with my car audio connections. For some reason, my power wire keeps burning fuses so I upgraded to a 100A fuse. Now Control will not work with the Marantz remote – you must use a universal remote, which can also be set up to control your CD player. The linking options on the motorised pot volume control are to select whether you want this item to be controlled by either the TV, CD, SAT1 or SAT2 selection on the remote. The alternatives are there so that there will not be a clash with the codes if, say, you have a TV, CD player or satellite receiver that also operates on one of these codes. The idea is to select either the TV, CD, SAT1 or SAT2 code that does not affect other equipment. So the link installed for your CD player is incorrect. Select either the SAT or TV codes. We did specify the codes that will work using the Altronics handheld unit. These are 651 for CD and 424 and 425 for Sat1 and Sat2. Try to get the pot working with these codes and the correct link. If this does not work, check your soldering for shorts between connections. Also, is there supply between pins 5 and 14 of IC1? Is there 5V between pins 2 & 3 of IRD1? the fuses on my amplifier are blowing. What gives? (M. R., Los Fresnos, California, USA). • Possibly the loudspeaker impedance is too low for your audio amplifier or maybe you have an intermittent short in one of your speaker lines. Always assume that fuse blowing indicates a fault. PowerUp won’t work with STB I purchased the Auto PowerUP (SILICHIP, July 2003) and finally got it to work. I want to use it to power a 240AC cooling fan when my Foxtel and/ or HDTV set-top boxes are turned on. However, I cannot get the adjustment on VR1 right; it is very sensitive! With careful adjustment, I can get it to switch the slave on (fan) but when the STBs are turned off (standby), the relay cycles continuously at six seconds on and three seconds off. The HDTV STB is 8W on Standby CON March 2005  103 75MHz NBFM Receiver For Fire Service I am a volunteer with the local fire department and although I have been issued a handheld radio for communication on the fire service frequencies, I would prefer to have a simple fixed receiver for listening while I am at home when the RT is off (thus saving battery life). FM transmitters are a dime a dozen (though all targeted at the 88MHz-108MHz FM band) but FM receivers are harder to come by. I would very much appreciate it if you could point me in the right direction to build a narrow-band FM receiver for the 75MHz band. I know I could purchase a scanner but I like to build things myself and and 22W on, while the Foxtel PACE box pulls 25W. The unit works well with a heavier current draw but can’t handle the lower power differential. Any suggestions would be much appreciated. (J. D., via email). • For more sensitivity, the 470kW resistor should be made larger, however, this is probably not going to help as there will be noise triggering the circuit. Instead, it may be better to increase the number of turns on the former of L1 former. You could place on 80 or more turns to double the sensitivity for detecting low current appliances. Multiple power supplies in parallel I was wondering if it was possible to connect multiple power supplies together to create a single high current supply? I have four spare notebook computer switchmode power supplies, all able to supply 20VDC <at> 4.5A and was wondering if there was a way of connecting them all together to provide a single output with 18A ability. Once I get to that stage I would throw in a regulator and filter circuit to make a cheap and very small 13.8V <at> 20A power supply to power automotive audio equipment from the mains. (S. R., via email). • It is not really practical because unless they each put out exactly the 104  Silicon Chip scanners are still expensive. The requirements are very straightforward, though I suspect, not simple: receive narrow FM on 75.xxxx MHz (the actual frequency depends on which repeater you use) and be stable enough that it doesn’t drift off frequency. The laws in New Zealand allow listening to these frequencies, so there should be no legal problem with this project. (N. Z., via email). • We described a narrow-band FM receiver circuit in the February & March 1989 issues. While it was intended for the 2-metre band, it should be easy to change the tuning to cover the band you desire. same DC voltage and have the same output impedance, they will not share the load equally. Guitar inputs for preamplifier Regarding the Balanced Microphone Preamp in the August 2004 issue which I want to use as a guitar preamp, could I add a guitar input or change the balanced input? How I could change the circuit to achieve this? (B. G., via email). • The balanced microphone preamplifier is not suitable for guitar use. Instead, you should use the Direct Injection Box from the August 2001 issue. This catered for guitar and had the same features, such as equaliser and powering options. Balanced mic preamp for amateur use I wish to use your Balanced Microphone Preamp (SILICON CHIP, August 2004) design for amateur radio transceivers and was wondering how to move the centre frequencies of the equaliser to better suit HF radio communications. Some commercial designs have 230Hz and 2.3kHz as centre frequencies. (P. N., Cairns, Qld). • The rolloff frequency of the bass control can be lifted to around 230Hz by decreasing the 15nF capacitor across VR2 to 6.8nF. The mid fre- quency can be shifted from 1kHz to 2.3kHz by decreasing the 2.7nF capacitor across VR3 to 1.2nF and decreasing the 12nF at VR3’s wiper to 5.6nF. Dummy C-cell battery wanted In the Circuit Notebook pages for December 2001 you mention a “dummy battery.” I have an exercise bike that requires four C-cell batteries but I would like to power it with an AC to DC multi-voltage adapter instead (which is easier and more economical). However, I can’t find C-cell sized dummy batteries that I could connect to the AC to DC multi-voltage adapter. What might you suggest? (R. S., Rochester, NY, USA). • While we do refer to a dummy battery in the article, in your case the simplest approach would be to just wire your multi-voltage adaptor (we call ’em plugpacks) directly to the appropriate contacts in the battery compartment. Either that or install a suitable socket on the bike battery container so that you easily plug in your adapter. Incidentally, we haven’t seen a dummy battery recently but you could make your own. Acoustic feedback with Champ I recently bought a Pre-Champ preamplifier kit (SILICON CHIP, July 1994) from Jaycar to use with an electret microphone and a Champ amplifier (February 1994). However, despite paying attention to the connections, the results are not satisfactory. If using a 12V source and an electret mic insert at the input, plus a pair of headsets in series at the output, I get good sound. However, when I connect the output of the preamplifier to the input of the Champ amplifier, which is connected to an 8-ohm speaker, the whole system goes into oscillation and produces a high pitch squeal. I tried another amplifier (50W) and got the same result. Please let me know what I should do to get the system working. (L. F. Auckland, NZ). • It sounds as though you have acoustic feedback from the speaker to the electret microphone – they must be kept well separated, as in any public address system. siliconchip.com.au Notes & Errata PICAXE-Controlled Battery Charger, September 2004 (Circuit Notebook): the charger works as described if the battery has not been discharged below the normal terminal voltage range. However, the author has recently modified the program to detect and charge batteries that have been discharged down to 2V. This update can be downloaded from the SILICON CHIP website – see www.siliconchip.com.au Note that the new program ignores input 3 (pin 4), so if building the circuit from scratch, all components associated with this input can be omitted. SMS Controller, October & November 2004: If a large SMS message is present in the “inbox” of the phone connected to the controller, it may fail to initialise. Instead, the “Comms Error” LED will come on for six seconds, go out for two seconds, then come on again, with the cycle repeating indefinitely. This situation is unlikely to occur in normal operation if the controller’s phone number has never been used for any other purpose. However, if the phone number is known to others, there is always the possibility of receiving large, unsolicited messages. Therefore, we’ve modified the microcontroller program so that it can successfully delete even the largest messages. An update is available from the download section of the SILICON CHIP website. Updated controllers can be identified by their response to the “COUNT” command – a reply of “v=01.01” indicates the latest program version. Note that this error condition can be cleared manually by deleting any messages in the inbox. Second, some constructors have reported a higher voltage than specified when measuring the phone power supply output with the 10W test resistor in place. This is due mainly to tolerances in the MC34063 and the 1.5W resistors and will result in a slightly higher charging current. If your measurement is 4.7V or less, it is within operating parameters and can be safely used as is. Alternatively, you can reduce the voltage to specified levels (3.6V 3.9V) by replacing one of the 1.5W resistors with 1.8W. We’ve received numerous reports of the controller not accepting commands after programming. In all cases, this has been due to the use of spaces after command words. As shown in the various examples and described in detail in the text, spaces must not be used immediately after commands (see page 77 of the November 2004 issue). This is not a bug! V8 Doorbell, January 2005: further research has enabled us to improve the characteristic “V8” sound. Some changes to the circuit are involved plus revised software. First, the resistor changes are: (1). The eight 100kW resistors connecting to the RB0 to RB2, RA3 and RB4 to RB7 outputs of IC1 are changed to 2.2kW. This boosts the cylinder output levels. (2). The 47kW resistor between pins 6 & 7 of IC3b is changed to 2.2kW. This reduces the gain of IC3b to compensate for the added cylinder output signal. (3). The 1kW resistor at pin 3 of IC3a is changed to 10kW to increase the engine ambient noise level. (4). The 100kW resistor feeding pin 5 of IC4 from the filtered PWM signal connecting to the top of VR2 is changed to 8.2kW to increase the RPM range. In addition, it is recommended that the 10mF capacitor in series with the 1kW resistor at pin 2 of IC5a be connected to ground rather than to the 5V rail. In addition, capacitor changes have been made to the filter components connecting between IC2b and IC2a. These are larger to provide a smoother sound: (1). The 68nF capacitor at the drain of Q1 is changed to 220nF; (2). The 56nF capacitor at the drain of Q2 is changed to 100nF; (3). The 1nF capacitor connecting between ground and the filter is changed to 100nF. Finally, the software changes alter the revving response and rev build up and decay rates. The revised software is designated ENGINE3.hex and is available on the SILICON CHIP website. WARNING! SILICON CHIP magazine regularly describes projects which employ a mains power supply or produce high voltage. All such projects should be considered dangerous or even lethal if not used safely. Readers are warned that high voltage wiring should be carried out according to the instructions in the articles. When working on these projects use extreme care to ensure that you do not accidentally come into contact with mains AC voltages or high voltage DC. If you are not confident about working with projects employing mains voltages or other high voltages, you are advised not to attempt work on them. Silicon Chip Publications Pty Ltd disclaims any liability for damages should anyone be killed or injured while working on a project or circuit described in any issue of SILICON CHIP magazine. Devices or circuits described in SILICON CHIP may be covered by patents. SILICON CHIP disclaims any liability for the infringement of such patents by the manufacturing or selling of any such equipment. SILICON CHIP also disclaims any liability for projects which are used in such a way as to infringe relevant government regulations and by-laws. Advertisers are warned that they are responsible for the content of all advertisements and that they must conform to the Trade Practices Act 1974 or as subsequently amended and to any governmental regulations which are applicable. siliconchip.com.au March 2005  105 ALL S ILICON C HIP SUBSCRIBERS – PRINT, OR BOTH – AUTOMATICALLY QUALIFY FOR A REFERENCE $ave 10%ONLINE DISCOUNT ON ALL BOOK OR PARTSHOP PURCHASES. CHIP BOOKSHOP 10% (Does not apply to subscriptions) SILICON For the latest titles and information, please refer to our website books page: www.siliconchip.com.au/Shop/Books PIC MICROCONTROLLERS: know it all SELF ON AUDIO Multiple authors $85.00 The best of subjects Newnes authors have written over the past few years, combined in a one-stop maxi reference. Covers introduction to PICs and their programming in Assembly, PICBASIC, MBASIC & C. 900+ pages. PROGRAMMING and CUSTOMIZING THE PICAXE By David Lincoln (2nd Ed, 2011) $65.00* A great aid when wrestling with applications for the PICAXE See series of microcontrollers, at beginner, intermediate and Review April advanced levels. Every electronics class, school and library should have a copy, along with anyone who works with PICAXEs. 300 pages in paperback. 2011 PIC IN PRACTICE by D W Smith. 2nd Edition - published 2006 $60.00* Based on popular short courses on the PIC, for professionals, students and teachers. Can be used at a variety of levels. An ideal introduction to the world of microcontrollers. 255 pages in paperback. PIC MICROCONTROLLER – your personal introductory course By John Morton 3rd edition 2005. $60.00* A unique and practical guide to getting up and running with the PIC. It assumes no knowledge of microcontrollers – ideal introduction for students, teachers, technicians and electronics enthusiasts. Revised 3rd edition focuses entirely on re-programmable flash PICs such as 16F54, 16F84 12F508 and 12F675. 226 pages in paperback. by Douglas Self 2nd Edition 2006 $69.00* A collection of 35 classic magazine articles offering a dependable methodology for designing audio power amplifiers to improve performance at every point without significantly increasing cost. Includes compressors/limiters, hybrid bipolar/FET amps, electronic switching and more. 467 pages in paperback. SMALL SIGNAL AUDIO DESIGN By Douglas Self – First Edition 2010 $95.00* The latest from the Guru of audio. Explains audio concepts in easy-to-understand language with plenty of examples and reasoning. Inspiration for audio designers, superb background for audio enthusiasts and especially where it comes to component peculiarities and limitations. Expensive? Yes. Value for money? YES! Highly recommended. 558 pages in paperback. AUDIO POWER AMPLIFIER DESIGN HANDBOOK by Douglas Self – 5th Edition 2009 $85.00* "The Bible" on audio power amplifiers. Many revisions and updates to the previous edition and now has an extra three chapters covering Class XD, Power Amp Input Systems and Input Processing and Auxiliarly Subsystems. Not cheap and not a book for the beginner but if you want the best reference on Audio Power Amps, you want this one! 463 pages in paperback. DVD PLAYERS AND DRIVES by K.F. Ibrahim. Published 2003. $71.00* OP AMPS FOR EVERYONE By Bruce Carter – 4th Edition 2013 $83.00* This is the bible for anyone designing op amp circuits and you don't have to be an engineer to get the most out of it. It is written in simple language but gives lots of in-depth info, bridging the gap between the theoretical and the practical. 281 pages, A guide to DVD technology and applications, with particular focus on design issues and pitfalls, maintenance and repair. Ideal for engineers, technicians, students of consumer electronics and sales and installation staff. 319 pages in paperback. by Sanjaya Maniktala, Published April 2012. $83.00 Thoroughly revised! The most comprehensive study available of theoretical and practical aspects of controlling and measuring EMI in switching power supplies. Subtitled Exploring the PIC32, a Microchip insider tells all on this powerful PIC! Focuses on examples and exercises that show how to solve common, real-world design problems quickly. Includes handy checklists. FREE CD-ROM includes source code in C, the Microchip C30 compiler, and MPLAB SIM. 400 pages paperback. By Garry Cratt – Latest (7th) Edition 2008 $49.00 Written in Australia, for Australian conditions by one of Australia's foremost satellite TV experts. If there is anything you wanted to know about setting up a satellite TV system, (including what you can't do!) it's sure to be covered in this 176-page paperback book. See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* PRACTICAL GUIDE TO SATELLITE TV See Review March 2010 ELECTRIC MOTORS AND DRIVES By Austin Hughes & Bill Drury - 4th edition 2013 $59.00* This is a very easy to read book with very little mathematics or formulas. It covers the basics of all the main motor types, DC permanent magnet and wound field, AC induction and steppers and gives a very good description of how speed control circuits work with these motors. Soft covers, 444 pages. NEWNES GUIDE TO TV & VIDEO TECHNOLOGY By KF Ibrahim 4th Edition (Published 2007) $49.00 It's back! Provides a full and comprehensive coverage of video and television technology including HDTV and DVD. Starts with fundamentals so is ideal for students but covers in-depth technologies such as Blu-ray, DLP, Digital TV, etc so is also perfect for engineers. 600+ pages in paperback. RF CIRCUIT DESIGN by Chris Bowick, Second Edition, 2008. $63.00* The classic RF circuit design book. RF circuit design is now more important that ever in the wireless world. In most of the wireless devices that we use there is an RF component – this book tells how to design and integrate in a very practical fashion. 244 pages in paperback. PRACTICAL RF HANDBOOK AC MACHINES By Jim Lowe Published 2006 $66.00* Applicable to Australian trades-level courses including NE10 AC Machines, NE12 Synchronous Machines and the AC part of NE30 Electric Motor Control and Protection. Covering polyphase induction motors, singlephase motors, synchronous machines and polyphase motor starting. 160 pages in paperback. PRACTICAL VARIABLE SPEED DRIVES & POWER ELECTRONICS Se e by Malcolm Barnes. 1st Ed, Feb 2003. $73.00* Review An essential reference for engineers and anyone who wishes to design or use variable speed drives for induction motors. 286 pages in soft cover. Feb 2003 BUILD YOUR OWN ELECTRIC MOTORCYCLE by Carl Vogel. Published 2009. $40.00* by Ian Hickman. 4th edition 2007 $61.00* Alternative fuel expert Carl Vogel gives you a hands-on guide with A guide to RF design for engineers, technicians, students and enthusiasts. the latest technical information and easy-to-follow instructions Covers key topics in RF: analog design principles, transmission lines, for building a two-wheeled electric vehicle – from a streamlined couplers, transformers, amplifiers, oscillators, modulation, transmitters and scooter to a full-sized motorcycle. 384 pages in soft cover. receivers, propagation and antennas. 279 pages in paperback. *NOTE: ALL PRICES ARE PLUS P&P – AUSTRALIA ONLY: $10.00 per order; NZ – $AU12.00 PER BOOK; REST OF WORLD $AU18.00 PER BOOK To Place Your Order: INTERNET (24/7) PAYPAL (24/7) eMAIL (24/7) www.siliconchip. com.au/Shop/Books Use your PayPal account silicon<at>siliconchip.com.au silicon<at>siliconchip.com.au with order & credit card details FAX (24/7) MAIL (24/7) Your order and card details to Your order to PO Box 139 Collaroy NSW 2097 (02) 9939 2648 with all details PHONE – (9-5, Mon-Fri) Call (02) 9939 3295 with with order & credit card details You can also order and pay for books by cheque/money order (Mail Only). Make cheques payable to Silicon Chip Publications. ALL TITLES SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST ALL S ILICON C HIP SUBSCRIBERS – PRINT, OR BOTH – AUTOMATICALLY QUALIFY FOR A REFERENCE $ave 10%ONLINE DISCOUNT ON ALL BOOK OR PARTSHOP PURCHASES. CHIP BOOKSHOP 10% (Does not apply to subscriptions) SILICON For the latest titles and information, please refer to our website books page: www.siliconchip.com.au/Shop/Books PIC MICROCONTROLLERS: know it all SELF ON AUDIO Multiple authors $85.00 The best of subjects Newnes authors have written over the past few years, combined in a one-stop maxi reference. Covers introduction to PICs and their programming in Assembly, PICBASIC, MBASIC & C. 900+ pages. PROGRAMMING and CUSTOMIZING THE PICAXE By David Lincoln (2nd Ed, 2011) $65.00* A great aid when wrestling with applications for the PICAXE See series of microcontrollers, at beginner, intermediate and Review April advanced levels. Every electronics class, school and library should have a copy, along with anyone who works with PICAXEs. 300 pages in paperback. 2011 PIC IN PRACTICE by D W Smith. 2nd Edition - published 2006 $60.00* Based on popular short courses on the PIC, for professionals, students and teachers. Can be used at a variety of levels. An ideal introduction to the world of microcontrollers. 255 pages in paperback. PIC MICROCONTROLLER – your personal introductory course By John Morton 3rd edition 2005. $60.00* A unique and practical guide to getting up and running with the PIC. It assumes no knowledge of microcontrollers – ideal introduction for students, teachers, technicians and electronics enthusiasts. Revised 3rd edition focuses entirely on re-programmable flash PICs such as 16F54, 16F84 12F508 and 12F675. 226 pages in paperback. by Douglas Self 2nd Edition 2006 $69.00* A collection of 35 classic magazine articles offering a dependable methodology for designing audio power amplifiers to improve performance at every point without significantly increasing cost. Includes compressors/limiters, hybrid bipolar/FET amps, electronic switching and more. 467 pages in paperback. SMALL SIGNAL AUDIO DESIGN By Douglas Self – First Edition 2010 $95.00* The latest from the Guru of audio. Explains audio concepts in easy-to-understand language with plenty of examples and reasoning. Inspiration for audio designers, superb background for audio enthusiasts and especially where it comes to component peculiarities and limitations. Expensive? Yes. Value for money? YES! Highly recommended. 558 pages in paperback. AUDIO POWER AMPLIFIER DESIGN HANDBOOK by Douglas Self – 5th Edition 2009 $85.00* "The Bible" on audio power amplifiers. Many revisions and updates to the previous edition and now has an extra three chapters covering Class XD, Power Amp Input Systems and Input Processing and Auxiliarly Subsystems. Not cheap and not a book for the beginner but if you want the best reference on Audio Power Amps, you want this one! 463 pages in paperback. DVD PLAYERS AND DRIVES by K.F. Ibrahim. Published 2003. $71.00* OP AMPS FOR EVERYONE By Bruce Carter – 4th Edition 2013 $83.00* This is the bible for anyone designing op amp circuits and you don't have to be an engineer to get the most out of it. It is written in simple language but gives lots of in-depth info, bridging the gap between the theoretical and the practical. 281 pages, A guide to DVD technology and applications, with particular focus on design issues and pitfalls, maintenance and repair. Ideal for engineers, technicians, students of consumer electronics and sales and installation staff. 319 pages in paperback. by Sanjaya Maniktala, Published April 2012. $83.00 Thoroughly revised! The most comprehensive study available of theoretical and practical aspects of controlling and measuring EMI in switching power supplies. Subtitled Exploring the PIC32, a Microchip insider tells all on this powerful PIC! Focuses on examples and exercises that show how to solve common, real-world design problems quickly. Includes handy checklists. FREE CD-ROM includes source code in C, the Microchip C30 compiler, and MPLAB SIM. 400 pages paperback. By Garry Cratt – Latest (7th) Edition 2008 $49.00 Written in Australia, for Australian conditions by one of Australia's foremost satellite TV experts. If there is anything you wanted to know about setting up a satellite TV system, (including what you can't do!) it's sure to be covered in this 176-page paperback book. See Review Feb 2004 SWITCHING POWER SUPPLIES A-Z PROGRAMMING 32-bit MICROCONTROLLERS IN C By Luci di Jasio (2008) $79.00* PRACTICAL GUIDE TO SATELLITE TV See Review March 2010 ELECTRIC MOTORS AND DRIVES By Austin Hughes & Bill Drury - 4th edition 2013 $59.00* This is a very easy to read book with very little mathematics or formulas. It covers the basics of all the main motor types, DC permanent magnet and wound field, AC induction and steppers and gives a very good description of how speed control circuits work with these motors. Soft covers, 444 pages. NEWNES GUIDE TO TV & VIDEO TECHNOLOGY By KF Ibrahim 4th Edition (Published 2007) $49.00 It's back! Provides a full and comprehensive coverage of video and television technology including HDTV and DVD. Starts with fundamentals so is ideal for students but covers in-depth technologies such as Blu-ray, DLP, Digital TV, etc so is also perfect for engineers. 600+ pages in paperback. RF CIRCUIT DESIGN by Chris Bowick, Second Edition, 2008. $63.00* The classic RF circuit design book. RF circuit design is now more important that ever in the wireless world. In most of the wireless devices that we use there is an RF component – this book tells how to design and integrate in a very practical fashion. 244 pages in paperback. PRACTICAL RF HANDBOOK AC MACHINES By Jim Lowe Published 2006 $66.00* Applicable to Australian trades-level courses including NE10 AC Machines, NE12 Synchronous Machines and the AC part of NE30 Electric Motor Control and Protection. Covering polyphase induction motors, singlephase motors, synchronous machines and polyphase motor starting. 160 pages in paperback. PRACTICAL VARIABLE SPEED DRIVES & POWER ELECTRONICS Se e by Malcolm Barnes. 1st Ed, Feb 2003. $73.00* Review An essential reference for engineers and anyone who wishes to design or use variable speed drives for induction motors. 286 pages in soft cover. Feb 2003 BUILD YOUR OWN ELECTRIC MOTORCYCLE by Carl Vogel. Published 2009. $40.00* by Ian Hickman. 4th edition 2007 $61.00* Alternative fuel expert Carl Vogel gives you a hands-on guide with A guide to RF design for engineers, technicians, students and enthusiasts. the latest technical information and easy-to-follow instructions Covers key topics in RF: analog design principles, transmission lines, for building a two-wheeled electric vehicle – from a streamlined couplers, transformers, amplifiers, oscillators, modulation, transmitters and scooter to a full-sized motorcycle. 384 pages in soft cover. receivers, propagation and antennas. 279 pages in paperback. *NOTE: ALL PRICES ARE PLUS P&P – AUSTRALIA ONLY: $10.00 per order; NZ – $AU12.00 PER BOOK; REST OF WORLD $AU18.00 PER BOOK To Place Your Order: INTERNET (24/7) PAYPAL (24/7) eMAIL (24/7) www.siliconchip. com.au/Shop/Books Use your PayPal account silicon<at>siliconchip.com.au silicon<at>siliconchip.com.au with order & credit card details FAX (24/7) MAIL (24/7) Your order and card details to Your order to PO Box 139 Collaroy NSW 2097 (02) 9939 2648 with all details PHONE – (9-5, Mon-Fri) Call (02) 9939 3295 with with order & credit card details You can also order and pay for books by cheque/money order (Mail Only). Make cheques payable to Silicon Chip Publications. ALL TITLES SUBJECT TO AVAILABILITY. PRICES VALID FOR MONTH OF MAGAZINE ISSUE ONLY. ALL PRICES INCLUDE GST MARKET CENTRE Cash in your surplus gear. Advertise it here in Silicon Chip. CLASSIFIED ADVERTISING RATES Advertising rates for this page: Classified ads: $22.00 (incl. GST) for up to 20 words plus 66 cents for each additional word. Display ads: $36.00 (incl. GST) per column centimetre (max. 10cm). Closing date: five weeks prior to month of sale. To run your classified ad, print it clearly in the space below or on a separate sheet of paper, fill out the form & send it with your cheque or credit card details to: Silicon Chip Classifieds, PO Box 139, Collaroy, NSW 2097. Alternatively, fax the details to (02) 9979 6503 or send an email to silchip<at>siliconchip.com.au Taxation Invoice ABN 49 003 205 490 _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ Enclosed is my cheque/money order for $­__________ or please debit my  Bankcard    Visa Card    Master Card Card No. Signature­­­­­­­­­­­­__________________________ Card expiry date______/______ Name _____________________________________________________ Street _____________________________________________________ Suburb/town ___________________________ Postcode______________ Phone:_____________ Fax:_____________ Email:__________________ 108  Silicon Chip FOR SALE PICAXE PROJECT PCB KIT for hobbyist and home automation, POWERMATE energy meter, thermochron temperature logger, ibutton accessories, ULN2803A driver, Luxeon Star LEDs, LED optics. info<at>techbits.com.au www.techbits.com.au ELECTRONIC ENGINEERING CONSULTANTS: Electronic Hardware and Embedded Software for Industrial Control and Commercial Communications. www.furzy.com.au Penguin temperature and humidity dataloggers N1500 universal process indicator. Displays thermocouple, RTD, 4-20mA and 0-5V readings Labjack USB Data Acquisition Module features 8 12bit analog inputs, 20 digital I/O, 2 analog outputs and high speed counter. Free software, Labview driver and ActiveX component. UHF 433MHz and Infra Red remote relay controller cards Serial and Parallel port relay controller cards Pump and Alarm Controller card. Programmers for Atmel and PIC microcontrollers. sPlan Windows electronic schematic software and Sprint Layout Windows PCB layout software are feature packed but low in price DAS005 Parallel Port Data Acquisition Module features 8 12bit Analog inputs, 4 Digital I/Ps & 4 Digital O/Ps. Free windows software and source code. Pixel Programmable Controller with 4 analog inputs, 8 digital inputs and 8 relay outputs. Uses a 28X Picaxe. Programmed in basic or Flow chart. 2, 4 & 8 Relay Cards suitable for TTL and Open Collector Outputs Stepper Motor and Servo Motor controller kits Switch Mode and Linear Power Supplies and DC-DC converters. Full details and credit card ordering available at www.oceancontrols. com.au siliconchip.com.au 2.4 GHz WiFi Antennas New New New  Foam surrounds,voice coils,cones and more Original parts for Dynaudio,Tannoy and others Expert speaker repairs – 20 years experience Australian agents for products Trade welcome – email for your user ID Phone (03) 9647 7000           Web: Email: Tel: Fax: Also Available Panel Antennas Ceiling Antennas Low Loss 50 ohm cable Connectors Pigtails Access Points Masts Amplifiers Power over Ethernet External Enclosures www.freenet-antennas.com sales<at>freenet-antennas.com +61 (8) 9319 3275 +61 (8) 9319 1720 speakerbits.com.au TAIG MACHINERY Micro Mini Lathes and Mills From $489.00 SUPERBRIGHT LEDS, LED testers, nixie tubes and nixie clock kits. New 6-digit nixie clock/panel meter kit coming soon! Lots of other neat stuff, and always more items being added. www. ledsales.com.au WEATHER STATIONS: windspeed & direction, inside temperature, outside temperature & windchill. Records highs & lows with time and date as they occur. Optional rainfall and PC interface. Used by government departments, farmers, pilots and weather enthusiasts. Other models with barometric pressure, humidity, dew point, solar radiation, UV, siliconchip.com.au • • • • • 6 Channels 10kHz frequency separation Size: 55 x 23 x 20mm Weight: 25gm Modular Construction Price: $A129.50 with crystal Electronics 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 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 USB KITS: GPIB Interface, Thermostat Tester, LCD Module Interface, Stepper Motor Controller, PIO Interface, DTMF Transceiver, Thermometer, DDS HF Generator, Compass, 4 Channel Voltmeter, I/O Relay Card, USB via LabVIEW. Also available: Digital Oscilloscope, Temperature Loggers, VHF Receivers and USB ActiveX (and USBDOS.exe file) to control our kits from your own application. www.ar.com. au/~softmark Mark22-SM Slimline Mini FM R/C Receiver PO Box 580, Riverwood, NSW 2210. Ph/Fax (02) 9533 3517 email: youngbob<at>silvertone.com.au Website: www.silvertone.com.au ELNEC IC PROGRAMMERS 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. Mega28 STAMP STARTER KIT, 4k BASCOM Compiler, MicroGUI-L, PSU, LEDs, Switches, Dual 7Seg, 830 Breadboard, introductory price $26 www. rhombus-tek.com PCBs MADE, ONE OR MANY. Any format, hobbyists welcome. Sesame Electronics Phone (02) 9593 1025. sesame<at>sesame.com.au www.sesame.com.au ImageCraft C Compilers: 32-bit Windows IDE and compiler. For AVR, 68HC­08, 68HC11, 68HC12, 68HC16. from $330.00 Atmel Flash CPU Programmer: Handles the 89Cx051, 89C5x, 89Sxx in both DIP and PLCC44 and some AVR’s, 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. Universal and specialised models High quality Realistic prices Large range of adaptors Free regular software updates Windows 95/98/Me/NT/2k/XP GRANTRONICS PTY LTD PO Box 275, Wentworthville. 2145. Ph: 02 9896 7150 www.grantronics.com.au 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 S-Video . . . Video . . . Audio . . . VGA distribution amps, splitters, standards converters, tbc’s, switchers, cables, etc, & price list: www.questronix.com.au CLUBS THE PIC CLUB meets 6pm, 2nd Tuesday each month. We discuss PIC programming and project design. 1st Floor, Sydney Mechanics School of Arts, 280 Pitt Street, Sydney. Phone: 9593 1025. March 2005  109 110  Silicon Chip siliconchip.com.au Do You Eat, Breathe and Sleep TECHNOLOGY? Opportunities for full-time and part-time positions all over Australia & New Zealand Jaycar Electronics is a rapidly growing, Australian owned, international retailer with more than 39 stores in Australia and New Zealand. Our aggressive expansion programme has resulted in the need for dedicated individuals to join our team to assist us in achieving our goals. We pride ourselves on the technical knowledge of our staff. Do you think that the following statements describe you? Please put a tick in the boxes that do: Knowledge of electronics, particularly at component level. Assemble projects or kits yourself for car, computer, audio, etc. Have empathy with others who have the same interest as you. May have worked in some retail already (not obligatory). Have energy, enthusiasm and a personality that enjoys helping people. Appreciates an opportunity for future advancement. Have an eye for detail. Why not do something you love and get paid for it? Please write or email us with your details, along with your C.V. and any qualifications you may have. We pay a competitive salary, sales commissions and have great benefits like a liberal staff purchase policy. Send to: Retail Operations Manager - Jaycar Electronics Pty Ltd P.O. Box 6424 Silverwater NSW 1811 Email: jobs<at>jaycar.com.au Jaycar Electronics is an equal opportunity employer and actively promotes staff from within the organisation. Advertising Index Amateur Scientist CD (House).OBC Alternative Technology Assoc......95 Altronics........................ loose insert Av-Comm...................................110 Dick Smith Electronics........... 26-31 Eco Watch..................................110 Elexol...........................................49 Evatco..........................................97 Excelsior Power............................49 KIT ASSEMBLY Satellite TV Reception 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 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°. WANTED WANTED: EARLY HIFIs, AMPLIFIERS, Speakers, Turntables, Valves, Books, Quad, Leak, Pye, Lowther, Ortofon, SME, Western Electric, Altec, Marantz, McIntosh, Goodmans, Wharfedale, Tannoy, radio and wireless. Collector/Hobbyist will pay cash. (02) 9440 1267. johnmurt<at>highprofile. com.au AV-COMM P/L, 24/9 Powells Rd, Brookvale, NSW 2100. Tel: 02 9939 4377 or 9939 4378. Fax: 9939 4376; www.avcomm.com.au Grantronics.................................109 Harbuch Electronics.....................61 Hy-Q International........................63 Instant PCBs..............................109 Jaycar ..................53-60,63,111,IFC JED Microprocessors................5,63 Microgram Computers....................3 MicroZed Computers....................94 Oatley Electronics........................79 Ozitronics.....................................62 NewTek Instruments.....................81 Nurve Networks...........................95 Prime Electronics.........................51 Quest Electronics..................63,111 RCS Radio.................................109 WANTED: CIRCUIT IDEAS. Make money out of your circuit ideas – see the panel in this month’s Circuit Notebook. NOW AVAILABLE FROM Freenet Antennas.......................109 RF Probes....................................97 Silicon Chip Binders................47,91 Silicon Chip Bookshop....... 106-107 SC Car Projects Book...........47,110 Perf. Electronics For Cars....112,IBC www.siliconchip.com.au Silicon Chip Subscriptions...........13 Silvertone Electronics................109 Speakerbits................................109 Taig Machinery...........................109 Project Reprints – Limited Back Issues –Limited One-Shots If you’re looking for a project from ELECTRONICS AUSTRALIA, you’ll find it at SILICON CHIP! We can now offer reprints of all projects which have appeared in Electronics Australia, EAT, Electronics Today, ETI or Radio, TV & Hobbies. First search the EA website indexes for the project you want and then call, fax or email us with the details and your credit card details. Reprint cost is $8.80 per article (ie, 2-part projects cost $17.60). SILICON CHIP subscribers receive a 10% discount. We also have limited numbers of EA back issues and special publications. Call for details! visit www.siliconchip.com.au or www.electronicsaustralia.com.au siliconchip.com.au Telelink.........................................63 ____________________________ PC Boards Printed circuit boards for SILICON CHIP projects are made by: RCS Radio Pty Ltd. Phone (02) 9738 0330. Fax (02) 9738 0334. March 2005  111 From the publishers of The Lat SILICON s t n e t n o C UND TECH BACKGRO Intelligent turbo timer I SBN 095852294 - 4 TURBO BOOST & nitrous fuel controllers 9 780958 522946 $19.80 (inc GST) NZ $22.00 (inc GST) How engine management works We’ll let the contents speak for themselves: Not a reprint – new projects and articles not published before Learn how engine management works Build projects to control nitrous, fuel injection and turbo boost systems Switch devices on and off on the basis of signal frequency, temperature and voltage Build test instruments to check fuel injector duty cycle, fuel mixture and brake and coolant temperatures P L U S L O T S MORE 112  Silicon Chip t Managemen ng Engine stems work di an st er R 1: Und engine sy 6 CHAPTEhandle on how the various Getting a ement ine Manag anced Eng r ECU functions dv A : 2 R TE he 14 CHAP yond spark and fuel – ot Going be c Systems lled systems in a car er Electroni th O : 3 nically-contro R tro TE 20 CHAP rundown on the other elec A quick Systems pensive as Electronic ex odifying Carstems is not as difficult or M : 4 R TE electronic sy 26 CHAP Understa Systems ur car’s Modifying yo ink you might th n Modificatio Electronic right wires IY D : 5 R TE e 30 CHAP multimeter and finding th Using a ct Kits c circuits ronic Proje lding Elect successfully build electroni ui B : 6 R TE to basic skills 36 CHAP You only need a few , voltage er A Multimet – here’s how to measure eter TER 7: Using 40 CHAP make do without a multim can’t You resistance current and INSTRUMENTS Meter modes art Mixtureal time, see the operating TER 8: Sm 42 CHAP ur car’s fuel mixtures in re -load “lean-out” occurs if a high Track yo d be warned of the ECU an Cycle Meter devices o jector Duty cycles or use it to switch In : 9 R TE P ty 50 CHA monitor fuel injector du Digitally ads nt engine lo ometer off at differe igital Therm perature D to an incredible 1200°C m Te h ig H : re su TER 10 out, can mea mperature 58 CHAP or LED read D et te It uses an LC off at a pres vices on or can switch de SWITCHES AND TIMERS g rnal triggerin Auto Timer : Versatile er with lots of uses and exte 1 1 R TE P A le tim 66 CH se adjustab A multipurpo h – lots r the bonnet ltage Switc : Simple Vog the sensors already unde switching 2 1 R TE P A e in id 72 CH on and off us to nitrous ox es rol Switch devic and fan cont water-spray of uses from y up to ture Switch rk all the wa 3: Temperajustable design that can wo 1 R TE P A H ad 77 C ral-purpose A cheap gene C 5° 24 4 RS ICS FOR CA E ELECTRON PERFORMANC siliconchip.com.au S M test From CHIP off witch equency Syou switch devices on and TER 14: Fr 82 CHAP eap adjustable design lets This ch speed according to Timer ta Throttle on and off, based on how es TER 15: Del 86 CHAP tricky way of turning devic A really iving ally you’re dr enthusiastic ne anding Engi s – p.6 ONTROLLERS MODIFIERS & C Controller LCD Hand – p.105 r rrecto Speedo Co – p.129 r se Adjuste to reduce t : Digital Pul noids in your car – use it extra fuel in 6 1 R TE P A le an l d so ro lse nt 92 CH pu co e or th control of g assistance t Managemen Take eerin ge power st boost, chan r d Controlle Adjuster, Dig 7: LCD Hanprogram the Digital Pulse rcuits 1 R TE P A H r ci r to lle lle ro ro nt nt 105 C Co co t nic Boos is plug-in Use th t Electro Independen Adjuster and daptor d Injector A u need this 8: Peak-Hold fuel injectors? – if so, yolse Adjuster 1 R TE P A H Pu -hol l ak ta gi pe Di 108 C ve , er ha your car Cycle Met Does e Duty tor to use th roller simple adap c Boost Cont ni tro ec El t en nd pe de In or el Adjustered to adjust air/fuel rat 9: Digital Fu 1 be us R -loop TE P A th H r to at can ange closed 112 C ltage intercep or swaps and even ch vo t an illi br A inject or er et m allow air-flow acteristics running char t oject will ge o Corrector tio? – this pr R 20: Speedission or altered the diff ra TE P A H C 129 t the transm tely again Swapped ou speedo reading accura r nic st Controlle your electro ctronic Booost maps at the flick of le E t en nd depe rbo bo tween two tu PTER 21: In 134 CHAine being able to change be just that do u yo Imag ts is project le a switch – th troller even just to s Fuel Con el supply or R 22: Nitrouinjector for the nitrous fu TE P A H C 149 ntrol an extra Use it to co fan speeds vary pump or Timer rd you’ve gent Turbo atch how ha R 23: Intelliengine idle-down time to m TE P A H C 154 er set the This turbo tim been driving Engine Advanced t – p.14 Managemen ture Smart Mix Meter – p.42 Capacitor : Resistor & ENDUM 160 ADD Codes om Jaycar The Kits available fr and. See Ze Where To Buyoject described in this Abousoktralariae an d New al ery pr l over details. Kits for ev d dealers al for further s stores an ck covers ba e id Electronic ts ou front and the inside p.50 cle Meter – or Duty Cy Fuel Inject om.au siliconchip.c r t Controlle Turbo Boos – p.134 Turbo Intelligent 4 Timer – p.15 om.au siliconchip.c Order direct from SILICON CHIP Publications Price: Aust. $A22.50 (inc. GST & p&p); Overseas $A26.00 (inc. p&p via airmail). Silicon Chip Publications Pty Ltd, PO Box 139 Collaroy, NSW, Australia 2097. Phone (02) 9939 3295; Fax (02) 9939 2649. Email silchip<at>siliconchip.com.au siliconchip.com.au March 2005  113