Fullscreen HTML5Med Res (??MB)HTML4

SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings.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.6; June 2005 www.siliconchip.com.au FEATURES   8 Looking At Laptops Laptop computers are growing rapidly in popularity. Here’s a look at what you get for your money – by Ross Tester 14 Getting Into WiFi, Pt.2 Setting up a wireless network? Ad-hoc networks are easy – by Ross Tester 76 PICAXE In Schools, Pt.2 The Mesmeriser LED Clock – Page 26. Writing programs that respond to input signals – by Clive Seager PROJECTS TO BUILD 26 The Mesmeriser: A LED Clock With A Difference This clock is spellbinding. Try taking your eyes of the circular 60-LED array that chases anti-clockwise each second to build up the seconds display – by Scott Melling 38 The Coolmaster Fridge/Freezer Temperature Controller It can turn your spare fridge into a wine chiller, or your old freezer into a very efficient fridge – by Jim Rowe 61 Alternative Power Regulator This simple shunt regulator is perfect for use with solar, wind and mini-hydro power generators and handles 12V or 24V systems – by Ross Tester Coolmaster Fridge/Freezer Temperature Controller – Page 38. 70 PICAXE Colour Recognition System Use a PICAXE micro and a state-of-the-art optoelectronic IC to create a lowcost colour recognition system – by Clive Seager 84 AVR200 Single Board Computer, Pt.1 It’s based on a fast ATMEGA32 microcontroller and can be programmed in both “C” and “BASIC” – by Ed Schoell SPECIAL COLUMNS 46 Salvage It! A voltmeter for almost nothing – by Julian Edgar 48 Serviceman’s Log Every storm has a silver lining – by the TV Serviceman PICAXE Colour Recognition System – Page 70. 66 Circuit Notebook (1) Solar Hot Water Controller; (2) Two Basic Motor Speed Controllers; (3) Op Amp Building Blocks 96 Vintage Radio Signal generators: what they are and how to fix them – by Rodney Champness DEPARTMENTS   2   4 19 92 Publisher’s Letter Mailbag Order Form Product Showcase siliconchip.com.au 106 Ask Silicon Chip 109 Market Centre 111 Ad Index AVR200 Single Board Computer – Page 84. June 2005  1 SILICON CHIP www.siliconchip.com.au Publisher & Editor-in-Chief Leo Simpson, B.Bus., FAICD Production Manager Greg Swain, B.Sc.(Hons.) Technical Editor Peter Smith Technical Staff John Clarke, B.E.(Elec.) Ross Tester Jim Rowe, B.A., B.Sc, VK2ZLO Reader Services Ann Jenkinson Advertising Enquiries Lawrence Smith Benedictus Smith Pty Ltd Phone (02) 9211 8035 Fax: (02) 9211 0068 lawrence<at>benedictus-smith.com Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Julian Edgar, Dip.T.(Sec.), B.Ed, Grad.Dip.Jnl Mike Sheriff, B.Sc, VK2YFK Stan Swan SILICON CHIP is published 12 times a year by Silicon Chip Publications Pty Ltd. ACN 003 205 490. ABN 49 003 205 490 All material copyright ©. No part of this publication may be reproduced without the written consent of the publisher. Printing: Hannanprint, Noble Park, Victoria. Distribution: Network Distribution Company. Subscription rates: $83.00 per year in Australia. For overseas rates, see the subscription page in this issue. Editorial office: Unit 8, 101 Darley St, Mona Vale, NSW 2103. Postal address: PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 9979 5644. Fax (02) 9979 6503. E-mail: silchip<at>siliconchip.com.au ISSN 1030-2662 Publisher’s Letter Photocopying is a huge cost to SILICON CHIP One of the really good aspects of all the emails we get from readers is the positive feedback. Many readers are so positive it almost becomes embarrassing. We try to make the magazine as entertaining and informative as possible, so it is very gratifying when people do write to say they like it. One such letter came in this week from a school teacher, singing the praises of the magazine in general and the PICAXE series of articles in particular. He loves it and so do the students. But there was jarring sentence at the end: “I hope it’s OK to photocopy 20 sets of the article for my students.” You would not believe how much that sentence hurt! Only a few minutes before that I had signed off on this year’s payment from the Copyright Agency Limited. The Copyright Agency is the legal body which oversees all photocopying done in universities, TAFEs, schools and libraries. On the basis of their recording of photocopying, the CAL makes an annual payment to publishers. All very well, you might say. And the amount to be paid SILICON CHIP for the whole of 2004, for all photocopying in all the above institutions? $701.75. Unbelievable. In fact, there is massive under-recording of photocopying in all these institutions and for years publishers have been complaining to the CAL that the whole system is severely inequitable. Some years ago, I spoke to a school teacher about this and given her knowledge of the extent of photocopying of magazine articles in her school alone, I asked her to estimate the annual copyright fee that would accrue to SILICON CHIP. She said it would be huge but when I pressed her for an actual figure, she said $26,000. When I told her the actual fee for that year, she was astonished. And while photocopying is rife in schools etc, what about all the photocopying being done elsewhere, in company laboratories and so on? We cannot put a figure on the lost revenue every year but it would undoubtedly make a large contribution to our costs. All of this is a fact of life and we have no legal recourse. All we can do is point out to all those people so enthusiastically photocopying is that each and every photocopy represents a loss of revenue. The same comment applies to all copying of course, whether it applies to magazine articles, books, CDs, software or whatever. Ultimately, this amounts to theft of intellectual property and it reduces the incentive for publishers of all media to continue in business. The music business is in very dire straits for this reason. So if you really like SILICON CHIP, one of the very few magazines of its type in the world, please remember that it takes a lot of resources to produce this magazine to a high standard. If we are to continue to maintain and raise the standard and to provide the service that you want, we do need your support. Letters of praise are nice but buying the magazine is more effective. And thanks to all those many thousands of enthusiastic readers who subscribe or religiously buy SILICON CHIP every month. Leo Simpson * Recommended and maximum price only. 2  Silicon Chip siliconchip.com.au June Stocktake Clearance We’d rather sell them than count them! LCD Monitor Arm This monitor arm supports 14" 15" and 17" monitors USB Serial Port with standard VESA mounts. No serial port on your new A 3 in 1 mounting system laptop? This mini USB to serial allows for desktop, wall or adapter is the answer! clamp mounting. Cat 2920-7 $54 Cat. 4666-7 $99 PDA Keyboard Adapter Switch your standard keyboard between PDA and PC mode. Cat 9229-7 $69 Analogue to Optical Audio Product of the month Bluetooth Headset - Pendant Style Tired of trying to balance a Bluetooth headset on the side of your head? Our pendant style headset hangs around your neck with a discreet earpiece for the speaker and a microphone embedded in the cable. Cat 11916-7 $129 Digital TV Tuner Watch free-to-air digital television on your PC. Digital TV is now broadcast by all major free-to-air channels. Cat 3564-7 $239 Projector Switch Box Great for the conference room! This eight way projector switch allows up to eight VGA inputs (PC/Laptop) to be switched between the one output (projector). Cat 3538-7 $499 4 Port RS232/422/485 Opto Isolated PCI Card Wireless Hotspot Perfect for conference rooms, cafes, VIP lounges etc. An all-in-one product specially designed for a Hotspot environment. It integrates "access control" and "wireless network access" into one system to fulfill the needs of a Hotspot. It supports 802.11b and 802.11g POS dual wireless transmission Cash Register mode. A thermal receipt printer Affordable ECR for small retail (not included) can be attached and speciality stores. Large to print out users account highly visible operator display. details, login details etc. Cat. 1008129-7 $289 Cat 11451-7 $1199 Broadband Input composite video and Router/Firewall stereo audio and convert Share any broadband connecthem to S-Video, digital audio tion and protect your network and optical audio. with this router/firewall. Cat. 23004-7 $129 Cat 10162-7 $129 What’s New? 12.1" LCD Monitor This tiny LCD screen is great for space critical situations. Cat 4658-7 $969 Provides four asynchronous RS232/422/485 jumper selectable serial communication ports. It has opto isolation, rated at 2500 Volts rms. Cat 2725-7 $595 Serial over Bluetooth Portable Data Terminal Turn any serial device into a wireless device using Bluetooth technology. Cat 11908-7 $459 USB VGA Adapter Add a second monitor and expand your desktop with this USB 2.0 adapter. Cat 15156-7 $199 Luminescent Keyboards Voice Activated A soft, even, blue light behind Remote the keys makes them perfect Replace your remote controls for use in dark or poorly lit with this unit and talk to your areas. technology. Cat 1008170-7 88 Key $69 Cat 1008171-7 105 Key $79 Cat. 9180-7 $239 Cardbus to RS422/485 Add two RS422/485 ports to any laptop. Cat 2999-7 $499 Digital I/O Card Provides 48 digital I/O lines on a PnP PCI interface. Cat 17053-7 $249 VGA Extender Extend VGA up to 130m over inexpensive STP cable. Cat 3441-7 $399 CCD Barcode Scanner This robust scanner is great for basic POS applications. Cat 8698-7 $269 Cable Tracer Single or multi-tone signal, two test leads and a 4-conductor modular cable. Cat 11520-7 $129 1Mb CCD RS-232 portable terminal includes power supply, and a free program generator. Cat 9239-7 $799 Serial to Ethernet Easily web enable your serial devices. Available in 1, 2, 4, and 8 port models. Cat 15141-7 (single port) $259 Mini 88 key keyboard Comes with a laptop style touchpad making it a great space saving solution. Cat 8751-7 $139 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 J 2005  3 siliconchip.com.au une SHORE AD/MGRM0605 Dealer inquiries welcome MAILBAG Defence technicians not all valve jockeys I must take you to task for allowing publication of the snide remarks by Keith Walters in his article on “The Start of Colour TV in Australia”. Maybe he found it necessary to spice up his otherwise very interesting nostalgic article by denigrating technicians from the war-time armed forces by including them amongst his “infamous valve jockeys . . . often there were a lot of these somewhat pathetic individuals (often ex-military with no real theoretical background)” then continuing on with his smug comments right through to “I suppose as long as there was a competent workshop to back them up, they could usually be relied upon to put in a reasonable day’s field work”. I really take exception to these comments as I was an RAAF WW2 Wireless Maintenance Mechanic trained by the RAAF through the Melbourne Technical College by completing the college’s normal 4-year radio mechanics’ course (I still have my course certificate issued by the college). I am not sure where the AIF wireless mechanics were trained or to what standard but as far as I am aware, all of the RAAF and RAN wireless maintenance mechanics did the above extensive training through the Melbourne Technical College (now RMIT). As for the RAAF, after completing this course, we were split up to progress into either wireless or RDF (now radar) maintenance. We then undertook months of practical training in, both HF and VHF, aircraft and ground-based receivers, transmitters and antennas. Some of us were also trained in telephony. Now if Mr Walters as a “bright-eyed 19-year old raised on a diet of EA/ ETI magazines” considered himself better theoretically trained, at the time, in radio theory than those of us who went through the Melbourne Technical College’s training course and then spent years in the armed services maintaining radio equipment, he must have been a very smart fellow. How 4  Silicon Chip would he shape up these days faced with servicing one of the latest hi-tech amateur transceivers? Not quite as easy to service as a TV. As I was involved for many years in TV servicing I am quite aware that, at first, there were many of the so-called “valve jockeys” as Mr Walters points out but at the time someone had to fill the gap until TV technicians could be trained. They soon passed into history. He should have let it go at that and refrained from trying to include or denigrate radio trained ex-servicemen in his slur. Yes many of them would have been struggling to come to terms with the arrival of the transistor age but training courses were available for those interested enough to upgrade their skills. Ron Mills, VK5XW, via email. Tsunami warning systems a problem There is no doubt that the recent tsunami in the Indian Ocean was an enormous tragedy. However, I would like to comment on Mr Simpson’s Publisher’s Letter in the February 2005 issue. In deciding how best to reduce the impact of tsunamis in the future, the economic state of the area must be taken into account. As Mr Simpson pointed out, there are tsunami warning systems currently in place in the Pacific Ocean. However, the countries with these systems (USA, Japan, etc) have the money to maintain these systems. Having been involved with the design and installation of dam flood forecasting systems in The Philippines and in North West Sumatra, I am aware of the harshness of life in these areas. The cost of the installation and maintenance of these systems is very high relative to the average person’s income. What makes these systems feasible is that they are associated with hydroelectric power stations which are a source of income for the maintenance technicians. If elaborate warning systems for tsu- namis are to be considered, the problem of expensive maintenance must be considered. In times of hardship, sometimes a permanent condition, it is very probable that the maintenance of this equipment will be neglected in many areas. The attitude would probably be that “such a disaster couldn’t possibly happen to us again!” I still think warning systems should be considered but I believe that simpler solutions should be implemented first. After the 1998 tsunami in Papua New Guinea, posters were placed around the towns, explaining how to identify an incoming tsunami, and what to do when it came – eg, “climb a coconut tree”. If people were better educated on how to identify a tsunami, people may be less likely to go and pick up fish on the beach, and more likely to run away. Posters are very cheap to maintain! Remember that Australia, a first world country and not so far from the New Zealand fault line, has no warning system in place because it has been considered difficult to justify. So let us proceed with tsunami forecasting but maybe delay a little to consider all the options. Peter Johnston, Coffs Harbour, NSW. Comment: if the reaction of the populace to more recent severe earthquakes is any guide, it will be many years before complacency about tsunamis ever sets in. These regions will be very keen to have any warning systems available. Matching the loop antenna to old radios At the end of the article on the Loop Antenna published in March siliconchip.com.au 2005, you mentioned impedance difficulties with direct connection to a radio. I used a Little Nipper I recently acquired and repaired (it’s the same as in Vintage Radio for September 2004 but with all the original knobs). It has no ferrite rod and presumably a very high impedance input. The loop performed very poorly. I found out that after connecting one end of the variable capacitor directly to the aerial input of the valve radio and not connecting the other end, I had a good signal with a strong peak when the loop is tuned. The radio is earthed through the mains, after following your advice about using a cheap extension lead. The signal was quadrupled when I connected about a metre of wire as a short aerial to the other end of the capacitor, without losing too much selectivity. The Little Nipper can now pick up well over 50 stations at nighttime that way, although some suffer from fading. Before I had perhaps five without disturbance. AM radio listening is now fun. Peter Mendelson, via email. automatic collators contain mainly mechanical parts and are a good source of drive belts. Lids with document feeders always contain a good motor and a PC board with the drive transistors (nearly always an H-bridge) that go with the motor. A bonus for building robots is when you find two identical motors and gearboxes, as this is ideal for building a skid steer base. Often, big companies will upgrade all of their photocopiers at the same time, meaning that if you are lucky you can get two or more identical machines to dismantle, always a good scrounging result! The most useful tool to have when reusing cogs and shafts is a small lathe. I have the Jaycar lathe (Cat TL4000) which is ideal for modifying the parts. Almost all motors in photocopiers run on 24V DC. They are assembled almost exclusively with M2 and M3 screws. Obtaining taps for these allows them to be reused. I hope this is useful to readers, Todd Noyce, RNZAF Whenuapai, NZ. Photocopiers are a treasure trove Current transformers revisited I have found that discarded photocopiers are a treasure trove for hobby robot builders. They contain power supplies that can be boxed up and used as is and one or more PC boards that contain reusable power transistors, hybrid module stepper motor controllers, switches, LEDs, etc. They also contain large quantities of mechanical parts, loads of plain and ball bearings, gears and cogs, toothed drive belts, electromagnetic clutches, DC motors, stepper motors, reduction gear-boxes, many shafts and rollers and a multitude of solenoids. They also make use of a large quantity of infrared vane detectors and a smaller number of infrared proximity detectors. Most of the proximity detectors only have a range of a few millimetres (to detect if paper is present); only really good for line-following robots. However, if you are lucky, you find ones that have a range of about 50mm, ideal for short-range collision avoidance. Photocopier accessories such as siliconchip.com.au I feel I must contribute my tuppence worth to the debate in Mailbag on current transformers. I am 50 years old and have been interested in electronics since I was a teenager. I have learned much from magazines like yours over the years. I have frequently found myself dissatisfied when circuit explanations avoided the finer points because analysis would be considered too complicated for the average reader. I am especially disappointed when the novice reader is left with a confusing and inaccurate analysis when there exists a relatively intuitive explanation, which is not very complicated. The problem with the three responses published in the April issue is that their arguments rely on the idealised transformer model which has infinite inductance and unity coupling between primary and secondary. They then try to explain away the inconsistencies this creates when looking at the transformer used in current mode. David Millist in the March issue correctly calculated that the second- 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 June 2005  5 Mailbag: continued ary load resistor “R” in his current monitoring transformer will appear as a primary load of “R/a2” where “a” is the turns ratio. The problem with this model is that when the secondary is open-circuit, this predicts an infinite resistance, even when reflected to primary side, and consequently no current can flow through the transformer or the primary load which is placed in series with it. Mr Denniss in the April issue brings up this exact point but fails to analyse it further. Mr Spencer in the same issue explains that current transformers operate in a different mode to voltage transformers, a notion I totally reject. After introducing the concept of magnetic flux induced by primary current, he goes on to say that the absence of secondary current means that the normal transformer rules cannot apply. If this was the case, what would one expect the secondary voltage to be on a voltage transformer, when the secondary is open-circuit? I have no doubt that it would be the primary voltage multiplied by the turns ratio and that the primary current could be calculated from the primary voltage, its waveform and the primary inductance. Assuming a sinewave primary voltage, i = v/wL; where w = 2p x frequency One gets a much better feel for the behaviour of transformers if you use a 4-port network model which is composed of an ideal transformer with the appropriate turns ratio and an inductance in parallel with the primary which has the same inductance as the real-world transformer primary. This model assumes that the realworld transformer has a coupling coefficient of unity and ignores other effects such as winding resistance, inter and intra-winding capacitance, losses due to induced currents in the core and core saturation. This model is developed in many text books on circuit theory (Hugh Skilling – “Electric Networks” and Lawrence Huelsman – “Basic Circuit Theory” are two examples). If one looks at the open secondary current transformer using this model, it is immediately apparent 6  Silicon Chip that the secondary voltage is equal to the voltage drop across the primary inductance multiplied by the turns ratio. It should be noted however, that this voltage is dependent on the rate of change of primary current and so harmonics and transients from such things as electric motors may produce secondary voltages which are higher than expected. A short circuit test load would leave the full mains voltage across the current transformer primary until the fuse blew. I would have expected this to be destructive, despite fuse protection. A secondary resistance R will have the same effect on the primary circuit as R/a2 in parallel with the primary inductance. If this is small compared with the inductance at the frequency of interest, it will have the benefit of providing a resistive current monitor rather than an inductive one. In summary: use a secondary resistance as this makes your current measurement insensitive to frequency. You could equally put it in the primary but it will have to be a lower value and will carry more current, perhaps leading to early failure. Peter King, East Doncaster, Vic. Powering devices from DC plugpacks Thomas Scarborough’s use of a diode bridge in his plugpack checker (SILICON CHIP, April 2005) made me realise that this configuration could be used to power equipment from DC plugpacks of either polarity. In this respect, the arrangement is better than the protection diode included in the DC line in many designs. The small voltage drop across the bridge (about 1.25V at low currents) could also be useful, given the poor regulation of many plugpacks. The use of a diode bridge in the DC line seems obvious once one sees it but is not an arrangement which comes readily to mind. I wish the designers of my old Panasonic cordless phone had included some protection against opposite polarity voltages in their design. Some time ago, I inadvertently con- nected the DC plugpack supply from my broadband router into the phone base. A loud splat and a bright flash told me immediately that I had done something wrong. The two pieces of equipment use DC plugpacks with the same voltage and current ratings but opposite polarity. Logic says there should be an agreed standard but apparently not, as I have seen a lot of commercial equipment where the central pin of the plugpack connector is negative rather than the more usual positive. With my Panasonic phone, I did manage to obtain a circuit and found that there is a transistor connected as a voltage regulator in the DC input line. Why a modern design would not use a voltage regulator with built-in protection is beyond me but that is another issue. I did hope that the regulator transistor may have blown before the following components were damaged. Replacing the transistor restored all the voltages to those shown on the circuit but the phone was still dead. At this point, I realised I was fighting a losing battle and bought a new phone. A simple diode or diode bridge in series with the DC line could have avoided $100 down the drain. My only consolation is that I did not connect the phone plugpack into the broadband router; that could have been even more expensive. Brian Knight, via email. Endorsement of High Energy Ignition This is a note of thanks to John Clarke for his Universal High Energy Ignition System published in SILICON CHIP, June 1998. My car is a Datsun 120Y vintage (almost) 1974 and during the winter of 1998 it chewed up a battery, a set of plugs, distributor points, rotor, distributor cap, distributor capacitor and a set of high tension leads. None of this fixed its stubbornness to start on a cold morning and its consumption was climbing to about a $1.00 a kilometre. While I was declaring to my wife, through a haze of blue air, that this car should be given a pension, I read John’s article. I immediately purchased a kit from siliconchip.com.au Dick Smith Electronics – anything was worth a try to stop the dollar haemorrhage. It was easy to build and install and it still functions reliably today. The only tune-up since this time, aside from spark plugs, has been replacement of a set of points whose rubbing block wore out. It is a pleasure not to be adjusting points every three months and driving a lively Datsun that has stopped chewing dollars. Thank you John! I’m a grateful fan, Bob Hammond, via email. Radiator fan running after engine turn off After reading the above letter, I was moved to offer my advice as a qualified mechanic. In modern cars, thermosiphoning just isn’t applicable. That technology hasn’t been in a workable automotive application since about the 1920s (Ford model T & A models) and maybe a few vintage tractors and stationary engines since. Further, aside from high perfor- mance applications, thermo fans and auxiliary fans are just a “band-aid” solution. My advice is for a cooling system overhaul which is really quite simple: full radiator and engine flush (until rusty water becomes clear), thermostat check, fan operation (consider viscous coupling, if fitted). If the radiator is easily dismantled, core check and clean, otherwise consider a new core or radiator. Also don’t forget your heater circuit. Paul M., Ararat, Vic. Basic theory of transformers I want to comment on the discussion about current transformers in the March & April issues. Talk about making transformers complicated; let’s get back to basics. Start by assuming a perfect transformer – no magnetising current, no core saturation, no winding resistance, etc. Now we can apply two simple rules to such a transformer: (a) the voltage on one winding always appears on the other windings, scaled according to the turns ratio; and (b) the current into all windings sums to zero, after applying turns-ratio scaling. Both rules always apply so that a transformer is ALWAYS a current transformer AND a voltage transformer. What differentiates the two in the real world is the intended application and therefore the design compromises. In a CT with an open-circuit secondary, the voltage on the secondary winding will increase until one of the following events occur: (a) an alternative conductive path is found in the secondary winding – usually due to high-voltage-induced insulation breakdown; (b) the full (primary source) voltage appears across the primary winding; or (c) the core saturates and the transformer ceases to behave as a transformer. Because of the way a CT is designed, (a) is far more likely to occur than either (b) or (c). Dale Rebgetz, Belgrave, Vic. LED Ha Gen NEfroW m Drop-in MR16 LED replacements for E standard Dichroic/Halogen Lamps M I PR ICS RON T ELEC Uses 3 Watt LEDs Low power consumption, 300mA <at>12V Input 12-24VDC or 12-18VAC 4 Shades of WHITE available 16 Colours available Up to 60 Lumens light output Wide beam angle 110° Total height 39mm (+ Pins) Long life >10,000 hours Multicolour unit with 3 LEDs (cycles through colour changing routine) Standard 50mm diameter. Fits directly into MR16 lamp housing No UV or Heat radiation (Runs much cooler than standard halogen lights) Conforms to IEC, CE & EN standards Bedlamp type and IP68 housings available soon. Visit us at: www.prime-electronics.com.au PRIME ELECTRONICS siliconchip.com.au Email us: sales<at>prime-electronics.com.au BRISBANE 22 Campbell Street Bowen Hills QLD 4006 Telephone: (07) 3252 7466 Facsimile: (07) 3252 2862 SOUTHPORT 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 June 2005  7 Looking at what you get for your money Toshiba Qosmio G10 There is no doubt that laptops (or notebooks if you wish) have grown in popularity in recent times. We thought it time to have a closer look at what you get for your money these days. W e’re actually looking at two “fairly” similar computers in this review. When we say fairly similar, they’re both advanced laptops offering incredible features. The biggest difference is one is a “big brand name” at or near the top of the price pile; the other was sourced from a supermarket at a (much!) lower price tag. Once, not so long ago, laptop computers were significantly more expensive than desktop models and suffered badly in performance comparisons as well. They’re still more expensive – but now the margins are nothing like as wide – and the gap in performance has reduced to the point where for most users it doesn’t matter too much, if at all. Throw in the convenience factor of laptops and it’s small wonder they have become the computer of choice for a wide range of users – everyone from business people on the go to 8  Silicon Chip students replacing notebooks with . . . notebooks! At SILICON CHIP, when we review equipment such as computers, we’re not so much looking at degrees of performance; we’re more interested in the overall picture, what readers would be interested in, what you get for your money and how well the equipment works in the real world. We generally leave A-B-C comparison tests, particularly when it comes to PCs, to those who are best set up to conduct them. You can find such tests in any of the myriad of computer magazines available in Australia (both local and imported) – or you can also scan the ’net and find report after report. A word of caution on the latter: you need to read these reports carefully because you usually don’t know if the reviewer has a vested interest to report a certain way. The way some reviews read it would appear that there might siliconchip.com.au t Laptops: in 2005! Medion MD 95400 By Ross Tester be some consideration. Of course, there are also straightup-and-down reports on the ’net; just be picky and choosy what you read! Let’s explain where the impetus for this review came from. It was actually at one of the exhibitions we regularly visit (we try to keep abreast of technology!) that one of the sales people showed us their brand new computer with more bells and whistles than you could jump over. “Ho-hum”, I thought. “Another new computer”. I generally don’t get too excited over new models. Maybe they’re a bit faster, maybe they’re a bit cheaper. Maybe they’re more snazzy looking. Maybe they’re . . . But my ears pricked up when the salesman started talking about its major claim to fame: it used the “new” Microsoft Media Centre operating system. He demonstrated some of the capabilities of this new system (at the time it was so new he didn’t really undersiliconchip.com.au stand all it could do; it was mostly the usual salesman “gee whiz” factor). But what I did see intrigued me. Microsoft Media Centre is an integrated system which effectively turns your PC into a multimedia home entertainment centre. It can easily become the heart of a home theatre system or it can be used for personal entertainment. At the time, I’d read a little about Microsoft Media Centre and (wrongly, as it turned out) assumed that it was a product in its own right, available “off the shelf” like Microsoft’s other operating system offerings. So I called Microsoft’s PR agency and asked them for a review copy of the software. The very nice lady at the PR company explained that they couldn’t do what I wanted because Microsoft Media Centre only comes “pre installed” on selected (suitable) computers. “And by the way, its not actually called Microsoft Media Centre” (though that’s what it’s become know as) – “its corJune 2005  9 (Centrino) with 400MHz front-side bus and 2MB L2 EIST), 1024MB DDR Ram (2048MB maximum), a 160GB hard disk, a SuperMulti double layer DVDR-RW, an NVidia Geforce FX Go5700 video “card” and Harmon-Kardon integrated speakers (which, by the way, sound surprisingly good given their obvious size limitations). It comes with 802.11b/g wireless installed, along with Bluetooth, a V.92 modem and a 10/100 LAN (network) card. Sorry about keep referring these things to cards – force of habit – they’re almost always integrated on the mainboard these days – but you get the drift! One nice feature of the Wi-Fi is a switch on the side to easily disable it. Many machines require menu selection or a series of keystrokes to do this – and it’s so easy to forget. If you’re on a plane or in some other area where 2.4GHz wireless is a big no-no, just switch it off. Toshiba also call the Qosmio G10 “compact and portable”. Umm, sort of like a wheelbarrow full of bricks is compact and portable. With that huge screen it’s certainly not too compact. Yes, it is portable but at a weight of more than 4kg you wouldn’t want to lug it too far. The most striking feature of the Toshiba Qosmio G10 is that big, beautiful, clear With a machine like this, we believe screen. It’s a pleasure to work with. We weren’t quite so impressed with having it’s more intended to be used as a deskto plug in the remote control receiver (on right). Shouldn’t that be integrated? top replacement, cable of being moved rect name is Microsoft Windows XP Media Centre edition.” around as required but not really the type of machine Hey, I’m not surprised it’s usually abbreviated! you’d want to bring home from the office each night nor take on holidays. Toshiba Qosmio G10 In fact, due to its size and the A/V features it offers, we’d By good luck or good management, another division of think of it more as the “works” of a home entertainment the same PR company looks after Toshiba, so she offered system. It was more than large enough to sit and watch in to send me one of the new Toshiba Qosmio (koz-mee-oh) its own right – but if you want to, it’s a quick plug-in to G10 laptops fitted, of course, with Microsoft Windows XP your larger TV set, home theatre system, etc. Media Centre edition,when it became available. This is one A 17-inch screen is roughly equivalent in size to a 43cm of Toshiba’s top-of-the-line laptops with a 17-inch screen. TV set which, as readers would know, is larger than many It took some time for one of these new machines to be- people have as their “second” set. And one thing we haven’t come available (they are in big demand amongst reviewers) mentioned yet is the fact that the Qosmio has full VHF and but in due course, arrive it did. UHF TV capability built in – so it can be your second TV To say it was an impressive machine is an understate- set (or even your first in a flat or small living room!). ment! The first thing that strikes you is that huge screen – a superb 17-inch WXGA (1440 x 900) CSV (a widescreen in TV-speak), capable of displaying 16:9 (widescreen) movies perfectly. And when you turn it on you notice just how good that screen is: big, bright and beautiful. (Toshiba claim to have special proprietary graphics chips built in to drive the screen. And it features two backlight tubes instead of the usual one). But computers need to be more than look good and have big screens, so we put the Toshiba to a variety of everyday tasks over the next couple of weeks until that inevitable phone call “We’re sending a courier to pick it up tomorrow . . .” OK, let’s lift the bonnet and have a look at what you get for your money. And it’s significant money, as we will discuss shortly. XP Media Centre edition helps you organise your movies, Toshiba describe it as “the ultimate digital entertainment photos, music etc and then either access them directly or hub”. In a nutshell, it is fitted with a 2.0GHz Pentium M via the remote control, or program them for later viewing. 10  Silicon Chip siliconchip.com.au One criticism you often see about Microsoft Media Centre is its inability handle digital TV. A pity, really: you get so much digital control in this machine but you can’t take advantage of digital television features! With a DVD player/writer/rewriter built in, you aren’t limited to the rubbish the TV channels are throwing at us lately. The TV tuner even has a remote control so couch potatoes need not worry . . . The DVD, incidentally, is a beauty: CD-R and –RW plus DVD-R, +R, -RW and +RW – and even dual layer DVD+R. One negative on the DVD is, like most brand-name DVDs, it is regioned. Personally, I find it offensive that manufacturers dare to tell me that I can only watch a pre-recorded DVD that they say I can watch – that is, one sold for region 4 (Australia/ NZ etc). Yes, you can change the region a limited number of times but once that number is up, you are stuck in that region. If you happen to be Not quite as large a screen on the Medion MD 95400 and you have to plug the TV receiver watching a region 1 (US) DVD in (that’s it on the side). But it does handle digital as well as analog! We found the glidepad at the time, all your Austral- took a bit of getting used to, too. But this computer offers exceptional value for money. ian DVDs are effectively coasters! (For most stand-alone – like a used mouse for $US1.99! No, we’re not kidding! DVD players there are firmware “hacks” available on the Now, while on the subject of price, let’s look at the Toshiba ’net to defeat this ridiculous zoning. So far I haven’t disQosmio G10. List price is $5999 – that’s right, one dollar covered one for the Qosmio but I dare say it will happen change from six thousand hard-to-get ones. You get a very eventually). large, powerful machine with a magnificent screen, with As far as A/V features are concerned, it’s hard to separate just about everything you could want built in or in the box. the “hardware” from the “software”. You get connectivity But we still choke a bit (no, a lot!) on six thousand dollars. for just about every application, in and out. And Microsoft OK, so what’s the alternative? Media Centre allows you to control (remotely if you wish – a remote control is included) every aspect – whether you Medion MD95400 are watching TV, recording hours of TV to hard disk for Readers would know there is a plethora of value notelater watching (no, you wouldn’t do that would you, that’s books available but one in particular caught our eye. illegal) or editing home movies. Around the same time as the Toshiba laptop arrived, we In fact Microsoft Media Centre means a PC retains 100% noticed an advert in our local paper from the German-based of its computer functions for when you need those but it “Aldi” supermarket chain. also turns it into a device which can organise and manage Featured product was a “Medion” laptop computer, selling your music, videos, photographs, etc – and all the devices for $2399. And the list of both features and inclusions was which gather these for you, such as video and still cameras, certainly impressive. Aldi appears to be the only distribution music sources, etc. It’s the ultimate in work and play! outlet for Medion (at least as far as we have noticed). It also effectively turns your PC into a Personal Video A glance at the (limited) information in the advert suggested Recorder (PVR) so, with a large enough hard disk, you don’t that the Medion was one very powerful machine and appeared need to buy another video recorder (digital or otherwise). to compare quite well with the Toshiba we were reviewing We said before that Microsoft Windows XP Media Centre . . . at well under half the price! edition is only available pre-installed on selected PCs – and It’s sold as a “widescreen multimedia entertainment notethe Microsoft Website confirms that. But I have discovered book” – not a Microsoft Media Centre notebook because, a US website where they are selling Windows XP Media naturally, it doesn’t have Microsoft Media Centre – “only” Centre Edition 2005 – “assuming” you are a system builder! Windows XP Home Edition (SP2). Price is usually $US134 but at time of writing (late April) it A lot more information was available on the Aldi website was on special at $US119.99, plus $US38.99 for the remote so we logged on and downloaded the PDF. Boy, was that control if you want one. (See http://shop.store.yahoo.com/ a surprise – apart from the Medion “only” having a 15.4direction/xpedia.html). inch, WXGA (1280 x 800) screen – not too shabby itself – it Oh, they do require you to purchase (at the same time) appeared to offer even more than the Toshiba. some piece of hardware to qualify as a “system builder” So we called Aldi (and that’s no mean feat, believe us!) siliconchip.com.au June 2005  11 and when we finally talked to (PowerDVD 6, Power Cinema, Unlike the Toshiba Qosmio, where the a human, suggested they might TV tuner is built-in, the Medion requires Power Director 3.0SE, Power like to submit one of their mathis plug-in TV and radio tuner module Producer 3, Medi<at>Show and Muchines for a comparison with (included in package). It plugs into the PC sicmatch Jukebox. the Toshiba. We weren’t overly pleased to (PCMCIA) slot on the side of the computer A week or so later Medion and the USB cable plugs into an adjacent see AOL 7.0 pre-installed, having USB port. The whip antenna can be had sad experience with AOL efAustralia contacted us and told replaced by a TV antenna connection. fectively hijacking machines in the us they’d be delighted to send While it’s not quite as convenient as the past and then not letting itself be us a laptop for review. When it Toshiba, the Medion has the advantage uninstalled. That was some time arrived, we still had the Toshiba of being able to handle both analog and – so comparisons were obvious. ago; perhaps AOL has listened to digital TV signals. The Toshiba cannot Yes, the screen is smaller (1.6 handle digital TV (actually, it’s the screams of anguish around inches mightn’t sound like much Microsoft Media Centre that the world. but side-by-side it certainly looks While the Medion HomeCincannot handle digital). that way). On the plus side, that ema might not be quite as tightly makes it a significantly smaller integrated as Microsoft Media machine overall. Centre, there didn’t appear to be It is also lighter – at 3.3kg, too much that you could do with it’s nearly 25% lighter than the one that the other couldn’t. We Toshiba. would have liked more time to One other major difference is play with Medion HomeCentre that the TV “receiver” for the to more adequately determine its Medion is not built-in, as it is full capabilities. But deadlines for the Toshiba. It’s an add-on loom large! device which slides into the PC In use slot on the side of the computer with a separate lead plugging We were very impressed with into the adjacent USB port. On both machines. Both did everythe plus side, this TV tuner does handle digital TV as well thing with aplomb and there were very few negatives. as analog. It’s also an FM radio tuner (watching radio on a We’ve already mentioned DVD zoning (the Medion had computer? Hmmm!). the same “problem” as the Toshiba – the manufacturers Its processor isn’t quite as fast as the Toshiba, with a probably call it a feature!). 1.7GHz Intel Pentium M735 mobile processor. It has 512MB We found the glidepad on the Medion took some getting of DDR RAM. The DVD is similar (8x multi-format with used to – it has a pseudo “wheel” built into the glidepad dual layer support) and there are four USB2.0 ports. which we kept drifting on to and finding we were transLike the Toshiba, it offers in-built wireless (802.11b and ported somewhere else! The glidepad on the Toshiba had g) and Bluetooth but it also offers Firewire (IEEE394).It too different problems for us – it is “intuitive”, reading certain has a 10/100 network controller and a 56K/V.90 modem. actions (such as tapping your finger) and translating them As well as its two integrated speakers they claim it has an into some other function. It’s a lot different to simply movinbuilt subwoofer (I’m not quite sure where!) and 6-channel ing your finger over the pad. You can turn this function audio out (analog and 2x digital) with ATI Mobility Radeon off but as this was a review machine, we thought it best 9700SE sound, itself with 128MB DDR RAM. to leave it set. One feature we found particularly useful is the 8-in-1 In both cases, enough experience would iron those card reader which can handle Compact Flash I and II, IBM minor difficulties out. It’s just that we are used to either a Microdrive, XD Picture Card, SD Card, MultiMedia Card, no-frills glidepad or a button “mouse”. Remember too that Memory Stick and Memory Stick Pro. the Medion does come with a USB mouse for those who, We’ve already mentioned the PC slot (PCMCIA if you’re an like us, might be digit-ally challenged! (Of course you could old timer); other interfaces include a VGA out (also doubles always fit a USB mouse to the Toshiba – these meeces are as DVI out with the adaptor included), TV out, Firewire, pretty cheap these days). LAN, modem, microphone, line-in, speaker rear, audio out Both machines offered the serious computer user virtual (or S/P-DIF optical), digital coax out and infrared out desktop performance but with the advantage of being fully Other hardware included is an infrared remote control, portable. Throw in their multimedia capabilities and they a stereo headset microphone and a USB scroll mouse. really do offer the best of both worlds. It’s when you start looking at what else you get with the “Fantastic” is a hackneyed word these days. But we Medion MD 95400 that the value becomes obvious. Actu- believe that while the Toshiba is a fantastic machine; the ally, it jumps up and screams at you! Medion is not far behind and offers fantastic value for Along with Windows XP Home Edition SP2, you also get money. Microsoft WorksSuite 2005 and MS Flight Simulator 2004; That rather significant price tag of the Toshiba really Nero Burning ROM 6, Nero RECODE 2-SE (DVD copying concerned us. $6000 can buy you almost half a small car software), Videon video and photo presentation software); these days! The Medion, on the other hand, offered seneTrust AntiVirus and Symantec System Recovery. sational value for money at $2399 – so much so that after In addition, there is Medion HomeCinema which itself the review machine went back, we went down to our local contains six programs for video and audio applications Aldi store and bought one! SC 12  Silicon Chip siliconchip.com.au POWERFUL DC MOTORS / GENERATORS: 4 brush, 4 magnet, 16 pole. 11 tooth sprocket to suit a chain pitch around 7mm. Double ball bearing for long life. Mounting bracket with 4 threaded holes 6mm X 1mm (M6) 100mm Dia. x 80mm L (+ shaft) Shaft: 27mm x 8mm (8mm x 1.25mm. (M8) 2kg. 200W 24VDC, 11.0A, 2750 RPM, $30 (SC200) 300W 24VDC, 16.4A, 2650 RPM, $36 (SC300) 450W 24VDC, 24.5A, 2500 RPM, $79 (SC450) WE HAVE SPEED CONTROLLERS, THROTTLES, BATTERIES & CHARGERS FOR THESE MOTORS, CHECK OUT OUR WEB SITE FOR MORE DETAILS. VALVE PRE-AMPLIFIER KIT: This low cost, simple to construct valve preamplifier allows you to experience "valve sound". It is based on a low power consumption sub-miniature pentode: Raytheon 6418: As used in super high quality AudioTechnica AT3060 microphones, Can be used with guitar amplifiers, hi-fi and mixers. Requ. 9V AC or 9-12VDC <at> only 20mA (onboard inverter). Kit includes power adaptor, PCB, & all onboard parts inc. RCA connectors & valve. (K188A) $33 ***NEW KITS***NEW KITS***NEW KITS*** NEW K220 12 or 24V SHUNT REGULATOR KIT. 7 CHANNEL INFRA-RED REMOTE CONTROL KIT Up to 3 kits can be used together to make a 21 Ch. system to operate from 1 remote. Kit inc. PCB & all onboard components to build a 3 Ch. IR remote control including relays & screw terminals. The extra parts required to expand to 7 Ch. are available in the K224E kit. If not used the remaining 4 Ch. section of the PCB can be snapped off to reduce the overall size of the kit. 3 channel kit $25 (K224R) 4 channel expansion kit $11(K224E) Remote control (pre-built)$6 (K224T) Complete package 7 channel kit with remote control $39 (K224P) Ideal for wind generators or solar power systems.It can be expanded for up to 250W operation or more with heatsink. This kit inc. PCB & all onboard parts for a basic 250W regulator kit. $26 9CH UHF REMOTE CONTROL RX AND TX KITS This 9-Channel UHF RX uses a pre-built & pre-aligned 433MHz UHF RX module (RX7). Switches any combination of 9 relays via a long range 9 button remote. Each of the relays has an indicator LED & can be set to momentary or latching mode. Remotely turn lights etc. on or off. Features inc. high security, on-board hi current relays & screw terminals. Req. 9VAC or 12VDC. RX kit inc. PCB & all on-board parts. The TX kit is based on pre-built 433MHz UHF TX module, very easy to build & req. no alignment. Req. 9V batt. (not supplied). TX kit inc. PCB, case, keypad label and all on-board components. (K226R) $55 (K226T) $27 L L L L L L L L L M M M M M M M M M NEW KIT...K221 SERIAL LCD INTERFACE This kit provides an interface between a 2400 baud serial line & common character type LCDs that use a HD44780 interface. It can use inverted or non-inverted data from a PC, PICAXE, or other processor. Features inc. software controlled variable backlight intensity, two auxiliary digital outputs & a "beep" output to drive a peizo speaker. The NEW 400W WIND GENERATOR: layout of this kit allows easy This high quality permanent magnet machine is very connection to 14 and 16 pin efficient, designed to run maintenance free even in single row & double row type 4CH UHF REMOTE WITH 4 LIMIT/RESET INPUTS marine environments. Precision injection molded blades. LCD connections. For more This kit switches any combination Consistent aerodynamic outline & mass distribution details check out our web of 4 relays via a Key-fob 4 button CHIP INCLUDED remote control. Each of the guarantees the rotors almost noise & vibration free. site. The kit includes a PCB, Designed to reduce start-up torque with very low start-up programmed PIC16F628 or ON relays has an indicator SO wind speed, high wind energy coefficient. Designed to similar PIC IC and onboard LED and can be set to NG prevent blades from feathering. High quality aluminum components. $20... momentary or latching MI casted body. Designed to operate under severe Add $10for a DL6 LCD. O mode. Each relay has an C conditions. Rotor diameter 1.4m, Start up wind speed (DL6) 16x2 BACKLIT LCD: input for external limit or 2.4m.s-1, Cut-in wind speed 3.0m.s-1, Rated wind speed Standard Hitachi chipset. Mounted on PCB with LED reset switches etc. to 12.5 m.s-1, Turbine Rated output 400W,AC12V, Survival backlight, onboard piezo buzzer driver and a piezo stop motors etc. when a limit is reached. K180B $44 with wind speed 60 m.s-1 NOTE: There is no mast included in transducer, microswitch, two colour LED. $12 1Key-fob remote. additional Key-fobs TX7 $11 the kit. (WG2) $1050 CLOCK / CALENDAR KIT: ZC0606 AMBIENT TEMPERATURE CONTROLLER This kit is a 12 hour car or home clock, FULLY PRE-BUILT: Mast kit special: This versatile unit could be can be used as a timer. Large(13mm) Our 4.5M 3 section mast comes with steel guy wires, used to control fans, heaters 15 $ turnbuckles, ground anchors, nuts and bolts.....all the Green LED display, AM-PM ) 6 or appliances.Control (K13 hardware you will need. $120. NOTE: If used with our LED, Date, Alarm with output, ventilation and use the outside new 400W Wind Generator you will need to make a sleep timer, Backup battery, Crystal air temperature to heat or cool controlled to 50Hz (20ms). 12V DC. PCB suitable adaptor as the pipe size is not the same. your house and save money. & all on-board parts & piezo speaker kit. NOW ON SALE FOR ONLY $449 Ideal for control of temp8W PET BED HEATER KIT: (NEW) 250W WIND GENERATOR: erature for wine cellars, These are serious three phase 250W wind generators This simple to construct kit will cooling, heating or drying with blades spanning 2.2M. They are designed to start make your pet very comfortable cabinets etc. Brand new in operating in low air speeds (around 11kph) while being this winter. Cheap to run. original packaging. Inc. LED robust enough to withstand strong gales. These Inc. the 9V AC <at> 1A plugpack. display and control unit, temp. generators are rated at 200W <at> 25kph with a maximum (K185) $18 controller unit, and thermistor. Features: Power On/Off of 250W, output voltages 12V or 24V. The charger kit PICAXE AND MICROPROCESSOR - GENERAL button, 3 fan speeds & auto fan mode, up to 5 modes (fan, (included with the generator) will enable you to charge PURPOSE DEVELOPMENT KIT: cool, dry, heat, auto), the option to turn On/Off sweep fan banks of batteries. Each generator is supplied with This kit can be used to program or run motor, freeze function, etc. Also measures room mounting plate, three blades, tail fin, nosecone, heavy PICAXE chips, most of the PIC ICs, temperature over a wide range. Operate from mains duty cable, 3 section galvanised mast , galvanised steel & many other chips. Cheap & easy 240VAC. Can be operated between 7-12V. Dim.: LED guy wires, turnbuckles, ground anchors, nuts & bolts..... to build. The kit includes a 28 pin display: 115x75x40mm, (STD electrical architrave plate all the hardware you will need to build your own wind DIL IC socket, a PC Serial interface, size) controller: 188 (W) x 102 (H) x 30 (D) mm. 0.6kg. $49 generator. Also included is a three phase rectifier unit plugpack KIT PRICE: (K193) $12.50 with voltage and amperage metering. These wind SPOT2 TWO LIGHT BAR SPOTLIGHT: AMAZING LIGHTING BARGAINS generators come in two boxes: Box 1 is 45kg (720 x 440 x 2 head barlight. Dimmable 12V electronic DL240 240V / 50W GIMBLE MOUNT 230mm), Box 2 is 27.5kg (1540 x 220 x 110mm). transformers. Inc. 4X 12V 50W Halogen LAMP HOLDER: DOWNLIGHT: INCLUDES A FREE K220 REGULATOR KIT lamps. Colour: Black. $28 Halogen lamp With one 240V / not supplied. 50W Halogen **WARNING: Only qualified persons should Colour: Brass. use these high intensity lasers!!! Blindness is lamp and $3.70 DL01 lamp holder. a potential danger if used and handled or Colour: Satin Chrome. $7.70 installed incorrectly. THREE LIGHT ROUND SPOT1 LOW VOLTAGE SPOTLIGHT: SPOT5 TRACK FLY1 (NEW) laser light show: PLATE SPOTLIGHT: Single flat head spotlight MOUNTED Three head round This professional quality with twist lock face. With SPOTLIGHT: plate. Dimmable 12V electronic transformer. light show features: Solid Track mounted collar 12V electronic Includes two 12V 50W head spotlight with 12V state laser diode, and emits transformers. Inc. Halogen lamps. electronic transformer. a powerful 30mW at a waveLASER 6X 12V50W lamps. Colour: Black. $14 Track not included. Inc. 2X length of 532nm, emerald green BLACK (SPOT4B) $42. 12V 50W lamps. Colour: Brass. $7 (DPSS). It is housed in a quality built WHITE (SPOT4W) $42 housing with mounting bracket Cooling: air HL1 (NEW) 12V / 50W HALOGEN SPOT3 THREE LIGHT BAR SPOTLIGHT: cooling, Power supply: 240Vac (Some 240VAC DICHROIC LAMP: 3 head barlight. Dimmable 12V electronic transformers. mains wiring may be required), Output: 30mW, In original packaging. 12 Volts, 50W, Inc. 6X 12V 50W Halogen lamps. Colour: Black. $42 60° . 50mm Dia. x 38mm. 1x 50W C o n t r o l : s o u n d / a u t o - p l a y, d i m . : LAMP: (HL1) $2.50. 340X116X119mm, 3.5Kg. ..$279 LAMP: 10x (HL1PK) $16. For more info on these check out our web site. L CIA E P S FLY1 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 BoxJune 89 Oatley NSW 2223 2005  13 major credit cards accepted, Post & Pack typically $7 Prices subject to change without notice ACN 068 740 081 ABN18068 740 081 OR www.oatleye.com siliconchip.com.au SC_JUN_05 GETTING INTO Part 2: setting up an ad-hoc wireless network by Ross Tester With WiFi hardware prices way down and Windows XP virtually doing it all for you, there’s no excuse not to set up a wireless network at home or in the office. The simplest network of all is the ad-hoc network. I n our introduction to practical WiFi last month we looked at the differences between the various wireless networking standards. Fortunately, setting up the two most popular, 802.11b and 802.11g, is pretty much identical. All you have to do is decide which type of wireless network you require. However, there is more to 802.11g than simply faster speed. They also (usually!) offer higher performance than 802.11b (see separate panel, “It’s more than just speed”). To briefly recap, there are two types of basic wireless networking: ad-hoc and infrastructure. For either type, for each computer to be connected to the wireless network you’ll need a Wireless Network Adaptor (they’re also known by a variety of other names, such as a Wireless NIC, or network interface card; Wireless Dongle, Wireless Card and so on). Many computers these days, especially newer laptops, come with the adaptor built in. But even many motherboards today offer integrated 802.11g facilities. If all you want to do is share files between computers, perhaps print a document on one computer via a printer attached to another, that’s all the hardware you will need. It’s called an ad-hoc network. It’s also sometimes called a peer-to-peer or computer-to-computer network. If you want to use your wireless network for more advanced tasks – to connect to the internet or to another network, for example – an infrastructure network may be required. And for that, you need another piece of hardware called an access point (AP). (Again as we said last month, access points can be entirely software – see separate panel, “SoftAPs”). And just to clarify one thing: just now (and last month) 14  Silicon Chip we said that if you want to connect to the internet, you may need an infrastructure network. We also said last month that Windows XP takes much of the hard work out of setting up any form of network (including wireless). Well, Windows XP goes even further than simplifying connection. It also allows you, via the “Sharing a Connection” option, to connect to the internet using an ad-hoc network. The steps are explained elsewhere but it is quite simple. Client, server, host, peer-to-peer . . . Before we get too much further, there are a couple of terms which you will find again and again so we should explain them. We just mentioned a couple of them – peer to peer (which simply means that the routing for the data is taken care of by the computers themselves, not by other hardware). The other terms you’ll often come across are “client” and “host”. Usually, a client is simply the user’s computer which accesses remote services on another, perhaps more powerful, computer. That computer is often referred to as the “host” but can also be known as a “server”. The name comes from the days when PCs were not as powerful as they are today. Organisations usually had one larger, faster, more powerful computer which handled most of the data manipulation – it was known as a server – and the computers which were networked to it relied on it for some, or most, or all, of their operation. In fact, often they weren’t really computers at all; they were dumb terminals which relied totally on the server to do all their “thinking” for them. There were also “print servers” whose sole (or main) job was to drive the printers siliconchip.com.au of the day. The term stuck when these new-fangled personal computers came on the scene! Think of the “host” as the main computer in your network. If you have an internet connection, it will be the computer which has that connection. Think of the “clients” as all the other computers. Why are we mentioning this here? Just to save confusion later . . . Setting up an ad-hoc wireless network The first thing to do when setting up any network – wired or wireless – is to draw a diagram of it. Here’s a tip: use a drawing program on your PC to do it – that way you will have it in the future if you need to refer to it. Yes, you do have a drawing program – “Paint” is more than adequate for the task. Of course, higher level programs will do even better. Give your network a name – a bland name which won’t arouse much suspicion if it is cracked is best – but write it down so that you remember it when it comes to adding the other computers to the network. This name can be something familiar, such as “johns network” – but it’s not wise to use your address (you may end up with more than bandwidth burglars!). As shown in the diagram published last month, an ad-hoc network has each of the computers directly talking to each other. There is no “intermediary” access point as there is in an infrastructure network . The first computer is assumed to be the “host” computer, with all others the “clients”. You need to set up the host computer first. XP or install disk? There are two ways to set up the ad hoc network. One, the way explained here, is to let Windows XP do it for you. It’s quite simple and Windows tries pretty hard to stop you making a mistake. The second way is to use the installation software provided with your wireless adaptor. Some wireless adaptors are pretty specific about NOT using Windows to set it up, probably because the installation program also loads its own drivers and perhaps proprietary software to give more features than Windows. One of the wireless adaptors we obtained from Dick Smith Electronics (NZ) came with a warning to use the installation disk, not Windows. Being the ornery types we are, we tried it both ways on different computers. Guess which method of the two didn’t work? (In fact, the Windows method caused us all sorts of grief which took some time to work through). It’s up to you: if the card documentation specifically warns you about using Windows, we’d probably go with that documentation. If it is non-committal or doesn’t even mention it, we’d go with Windows. 802.11b vs 802.11g – Stan shows it may be more than just speed! Last month, we stated that 802.11“g” offers significant speed advantages over the older 802.11“b” standard – a raw throughput of 54Mbps versus 11Mbps – as well as some advantages in the way it handles the packets of data. But there is even more to it than that. Following further experimentation with USB “b” and “g” adaptors, it is apparent that at least the “g” devices I’ve tried also offer superior weak signal reception. Compare the Netstumbler* graphs below. A Genius GW-7200U “g” (~AU$50) showed about 10dB better signal levels, from an obscured acess point (AP) 100m away, when trialled beside a classic DSE Zydas “b”. When placed at the focal point of a 300mm cookware parabola (see “WiFry”, SILICON CHIP, September 2004) and directed over NZ’s Wellington harbour, the USB Genius “g” later found many previously undetected APs (at approximately -80dBi) some 10km line-of-sight (LOS) away as well. However, the limiting factor now looks to be one’s weak outgoing signal (the Genius is only 16dBm or 40mW), meaning powerful remote access points may be heard but NOT connected to. Argh! Just because you can detect them (via Netstumbler etc) doesn’t mean they can hear YOU, since their reach is greater than yours. Either a costly (and possibly illegal) transmitter booster would now be needed, or improved focusing for your weak outgoing signal via a higher gain antenna. * Netstumbler www.netstumbler.com is invaluable for adaptor testing, AP detection, site coverate auditing and even antenna tweaking, while the Pocket PC “WiFiFoFum” (WFFF) www. aspecto-software.com/WiFiFoFum/ also allows more convenient compact PDA-based monitoring. Both are free downloads. The Windows XP route Turn the computer off and install the wireless adaptor, what ever its incarnation (USB dongle, PC card, etc for a laptop or desktop, internal wireless card for a desktop, etc). Turn the computer on and Windows XP will automatically detect the card and install its drivers. In some cases, Windows might not be able to find the drivers but unless you’ve acquired the card from a dubious source, it will come siliconchip.com.au Using Netstumbler to compare the “Genius” GW7200U WiFi adaptor (“g”) with the Zydas (“b”), with and without the “WiFry” parabolic scoop reflector. They’re looking at the same access point, about 100m away, through trees and buildings. Although the scoop gives around the same gain (~15dB) with each USB adaptor, the (newer) “g” dongle is showing far superior weak-signal performance (and therefore range?). June 2005  15 Fig.1: this computer has accessed a variety of wireless networks in the past – hence the list. Notice the little red “X” through the icon. That means it can’t find them at the moment. Fig.3: now we’re adding the new wireless network – it’s called “Ford Prefect”. At the moment, we’ve disabled encryption to make sure the network gets up and running without hassles. with drivers (usually on a CD). The computer will then look for wireless networks in range and if it finds any, automatically display a list of them in a box called “Wireless Network Connection Properties”. If, by chance, it does display them, don’t connect to any of them – you want it to connect to YOUR wireless network, not someone else’s! We’ll assume that there are no wireless networks in your neighbourhood, so it won’t find any. The “Preferred networks” field should be blank. If your computer previously connected to a nearby wireless network (eg, somewhere else!), make sure you disconnect it (use the disconnect tab). Previously found networks will almost certainly be listed but if they aren’t in range, there should be a small red cross through their symbol, as shown above. Now click on the “Advanced” tab (top of window). Select “computer to computer (ad hoc) networks only, and if the “automatically connect to non-preferred networks” box is ticked, untick it (again, to make sure you connect to your ad hoc network). Now click on the “Wireless Networks” tab again. See the “add” box down below. Click it and type in your network name (the one you wrote down before) in the box marked Network name (SSID). SSID stands for Service Set Identifier – and now that you know that, forget it. Just think of Fig.2: we want this to be an ad hoc (ie, computer-tocomputer) network. Here’s where we select this option. Fig.4: and then we can see that not only is the “Ford Prefect” network available, “320-nile” is also there. But it’s protected. 16  Silicon Chip siliconchip.com.au Fig.5: one of the easiest ways to check that the network is working is to check that packets are received as well as sent. That means another computer can talk to yours. SSID as meaning network name! Just for the moment (and only for the moment!) we’re not going to turn WEP on just yet. Despite our dire warnings last month, it does add one more thing to go wrong when setting up the network. So until we have everything working, leave it off. Your host computer installation is now complete. The SSID should now be displayed in the “Preferred networks” field. But there will be a red “X” displayed, telling you that there are no other computers (yet!) in the wireless network within range. Setting up the client computer Basically, it’s just a matter of repeating the above steps for each computer you want to add to your ad hoc network. The main difference is that you don’t need to put in the SSID because when the two computers are in wireless range, the SSID should automatically come up in the “available networks” window. Select configure, turn off WEP and you should find that the computers can talk to each other. It really is that simple! Turn WEP (or preferably WPA) on . . . Now that it’s all working, it’s time to go back and turn WEP (Wired Equivalent Privacy) on. As we said last month, WEP stops the casual snooper from getting into your system and either using your bandwidth or perhaps doing something nasty. WPA (WiFi Protected Access) is much more robust and, if your hardware will allow it, WPA is much preferred. If using WEP, starting with the host computer, click on the Wireless Network Properties tab and click on “Data encryption (WEP enabled)”. siliconchip.com.au Most modern wireless adaptors support 128-bit encryption – the more bits, the harder it is to break. Older adaptors may only support 64-bit – Windows XP will automatically detect this in most cases and not let you enter 128-bit. Your network key ideally should consist of random letters and numbers (some setups do allow plain English which is then used to generate a key). Don’t be tempted to use birthdays or addresses – you want something that cannot be guessed. And remember to write it down somewhere – on your network plan, for example? Repeat the setup for all computers on the network Remember that if you get a key wrong, the computer will not be able to talk to the others. As mentioned, WPA is definitely preferred – use it if you can. It’s a lot more difficult to hack (vital if using the net for business and/or finance) and has plain word generation of the encryption key. A salutory warning Remember last month I mentioned that I was sharing internet access with my next-door neightbour? A couple of weeks ago, my computer started grabbing a completely unprotected wireless network, giving me full broadband access. At first I thought my neighbour’s AP had somehow reset itself without WEP – but no, it all checked out properly. A few days later, when talking to my neighbour on the other side I asked if he had recently installed a WiFi network. He looked at me as if I had two heads, both speaking Swahili – so I took that as a “no”. But his son, who was listening in, sheepishly said “Umm, yeah, I have . . .” June 2005  17 Fig.6: here’s where you turn on your Windows firewall (essential!) and allow other computers internet access via the Internet Connection Sharing check box. SoftAPs – Winmodems all over again? Need to link several WiFi users with a barebones budget? You may not even need an AP (access point)! We mentioned last month that access points can be “constructed” entirely in software. Suitable programs can convince some WiFi cards to act as a software based “soft AP”, promising instant multi-user laptop based WLANs that suit on-the-road meetings, events etc. Although such programs, especially HostAP and AgileAP, are popular under Linux , Windows versions are still evolving, with PCtel’s US$20 “softAP”(www.pctel.com) perhaps best known. As well as an always-on PC, you’ll still need a wireless card but the approach saves carrying yet another piece of equipment when on the road. Many new Asian-sourced “g” WiFi cards increasingly offer such a “soft AP” option as well as the normal adaptor function. Although this idea has appeal for experimenters and light duty residential users, it rather harks back to hybrid-softwarebased Win98 56K “WinModems” of the late 1990s – the cause of much hair-pulling and teeth-gnashing in dial-up modem days. It also has considerable scope for mischief, since an otherwise innocent-looking laptop may tempt nearby WiFi users to log on (perhaps even automatically) and divulge sensitive password details. Given the rapid fall in hardware-based AP costs, “soft APs” may have limited appeal, although the feature may well come inbuilt with future motherboards and operating systems. (From Stan Swan) 18  Silicon Chip Fig.7: finally, when you’re happy that everything is working as it should, don’t forget to turn data encryption back on again, on all computers on the network. Neighbour then said “I guess we have then!” I think both were a bit shocked when I told them I had full ’net access via their WiFi setup! “Sharing the Connection” under Windows XP This assumes that you have successfully set up the ad-hoc network. 1. Open Network Connections on the host computer. (Click Start, Control Panel, Switch to classic view, and then click Network Connections. 2. Click the connection to be shared and under Network Tasks, click Change settings of this connection. 3. On the Advanced tab, select the “Allow other network users to connect through this computer’s Internet connection” check box. 4. If you are not using a third party firewall and have not already set up the Internet Connection Firewall (ICF), be sure to check the box enabling this feature. 5. Finally, enable the setting to let other users control or enable this connection if you wish that to be possible. Unfortunately, space has beaten us – we had hoped to cover AP infrastructure networks as well this month – but that will have to be another time! SC NEXT PART: We’re going to go for long-distance WiFi, using some high-gain antennas and tricky gear from Freenet-Antennas. Our aim is pretty modest – just a kilometre or so – but there are trees in the way! 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, June 2005  19 Australia 2097 06-05 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 Design by SCOTT MELLING* *Grantronics Pty Ltd. A LED Clock with a difference Here’s a LED digital clock with a difference – a circular 60-LED array which chases anticlockwise each second to build up a count of seconds until it gets to 60, whereupon the chase starts all over again. The effect is mesmerising. Have you even been accused of being a clock-watcher? Whether you have or not, there is a definite risk of being entranced (enchanted?) with this new LED digital clock. You tend to ignore the central 4-digit display and just concentrate on that magical circular LED performance. At the beginning of each minute, each successive LED races anticlockwise around the periphery to take up its position as the seconds count builds up. As the seconds count nears 26  Silicon Chip 30, each new LED only has to traverse half the circle and so each LED makes its circuit slightly slower than the last until finally, as the count approaches 60, the last few LEDs make the transit very slowly indeed. But each LED transit around the circle, whether it covers the whole 360° or just a few, takes exactly one second. So you find yourself wondering: just what fancy machinations have been pulled to achieve that? The answer is, of course, that there is a fancy microcontroller calling all the shots. But even knowing that and having considered all the programming that must have gone into it, you still tend to sit there mesmerised by this clock. You just have to see it but be warned – when you do, you will probably want one! Apart from that magic circular LED array, this wall clock also has a 4-digit readout with 12 or 24-hour operation. It also features an alarm with piezo sound and opto output, a battery backup for time-keeping and alarm functions, AC mains synchronisation and crystal timebase for precise timing, an efficient switchmode supply powered by a 12V AC plugpack and a high quality double-sided, screenprinted and solder-masked PC board with plated-through holes. What more could you want? The hours and minutes display consists of the four large digits in the siliconchip.com.au How The Seconds Chaser Works centre of the clock face. It can be set to display either 12 or 24-hour time, depending on the position of a single jumper link (JP1). On the righthand side of the minutes digits is an AM/ PM indicator LED and this is active for PM hours if the 12-hour display mode is chosen. The timing uses a crystal oscillator for short term accuracy with the chaser control and is synchronised to the mains AC cycles when present for long term accuracy. The clock’s alarm features need explaining. Apart from the piezo buzzer that can be set to sound as an alarm, there is an optocoupler output which allows the clock to trigger an external device. Once both or either of these outputs has been enabled and becomes active, they can be reset by pressing any of the three time-setting buttons on the back of the clock. There is provision to connect a backup battery to the clock for periods when the mains power fails. When running from the backup battery, the LEDs are not illuminated, to enhance battery life. Unlike many other designs, however, the alarm output and opto output will still activate during a mains power failure. The battery backup circuit also includes a charging facility so that NiMH or Nicad cells can be used. There are three buttons on the back of the clock labelled UP, MODE and DOWN. The functions of these buttons vary depending on which “mode” the clock is currently displaying. Four seconds into the minute. At the start of each second, the chase LED starts at the top and travels anticlockwise around the clock face, as indicated by the green arrow. Eighteen seconds into the minute. The chaser LED is shown here travelling anti-clockwise past the 40s mark. Note: the green arrow is not part of the clock display. Thirty seconds into the minute. The chase LED is now really starting to slow down, since it has much less distance to travel in 1s. Forty-seven seconds in and the chase LED is getting slower and slower. It now travels less than 45° of arc in one second. Coming down the straight . . . the chase LED moves very slowly during the last few seconds of the minute. Finished – 60 seconds is up and the minutes digit “ticks” over. The seconds LEDs now go out and the chase sequence starts again. Menus and setup When AC power is first applied, the clock will power up and proceed to run, beginning with a default time of 0:00 and 0 seconds. This is the “run” mode, identified by the standard LED chasing pattern described above. In all other “utility” modes, as set by the MODE button, there is a very different chase sequence to indicate you are not in “run” mode. In the “time-hours set” mode, the hours digits display as “Ch”. You can then press the UP and DOWN buttons to set the clock’s hours. In “time-minutes set” mode, the hours digits display as “C” and pressing the UP and DOWN buttons allow the clock’s minutes to be set. In “alarm/opto enable” mode, the UP button toggles the alarm on and off. When enabled, the hours digits siliconchip.com.au show “AL.” The DOWN button toggles the opto output on and off. When this is enabled, the minutes digits reads “Au.” In “alarm-hours set” mode, the hours digits display “Ah” while in “alarm-minutes set” mode, the hours digits display “A .” Using the UP and DOWN buttons in both modes allows the clock’s hours or minutes display to be set for alarm triggering. The same comments apply to the “opto-hour set” mode (display “Hh”) and “opto-minutes set” (display “H”). June 2005  27 (LD61) is enabled (ie, it lights after 12 o’clock midday). Conversely, shorting pins 2 & 3 with a jumper converts the clock to 24-hour operation and disables the AM/PM indicator LED. Programming header As well as JP1, Fig.1 also shows a 6-way pin header connected to pins 9, 6, 8 & 7 of the microcontroller. This header was included during development to allow for in-circuit programming of the microcontroller and has been retained for those who like to experiment. Most people will not want this facility, in which case the pin header can be left off the PC board. Power supply The LED clock comes as a complete kit of parts and includes a double-sided plated-through PC board with a solder mask and silk-screened overlay. When triggered, both the audible alarm and the opto output are disabled by pressing any of the pushbuttons. Circuit description The brain behind the operation of the clock is an Atmel ATMEGA851516PC microcontroller – see Fig.1. It runs at 8MHz, which gives approximately 8MIPS throughput with a machine cycle of 125ns – eat your heart out Microchip! The PC board layout was actually designed for the now obsolete Atmel AT90S8515, together with its MC34064P-5 under-voltage sensor (U4), but the ATMEGA8515 is a dropin replacement. It also incorporates an on-chip under-voltage detector which has made the MC34064P-5 redundant. The ATMEGA8515-16PC will operate happily down to 2.7V, relying on its own internal brownout detector. The short-term timing of the clock is derived from an 8MHz crystal but this may drift slightly over several months. To help combat the drift problem, the micro samples the AC mains supply, comparing this cycle count every hour to the expected cycle count for the 50Hz (or 60Hz) AC supply. If it is close to being in sync, the assumption is that there has been some small drift and the micro is re-synchronised. If there is a large difference, the assumption is that the AC mains supply 28  Silicon Chip is not present or was not present for a part of the last hour’s operation, and the synchronisation process is skipped for that time around. LED arrays All of the LEDs on the clock face, except the LED that sits in parallel with the buzzer, are in three 5 x 7 matrices. Each LED in each matrix is individually controllable except in the case of the digits where each segment is controllable. Seven bits of ports A, C and D on the ATMEGA8515 are used to drive three ULN2003 7-way Darlington transistor drivers (ie, driving three matrices), allowing the clock to multiplex up to 21 LEDs on at any one time. There are five BD682 PNP transistors on the supply side of the LED arrays, breaking it into parts that can be time division multiplexed with about a 20% duty cycle. The base cycle time used is 1ms, so each LED (if required) is on for 1ms in every 5ms. The associated 220W resistors limit the current in any LEDs that are active. Display format The 3-way pin header labelled JP1 is used to control the display format – ie, whether the clock shows 12-hour or 24-hour time. If pins 2 & 3 are left open circuit, the clock operates in 12-hour mode and the AM/PM indicator LED Power for the clock circuit is derived from a 12VAC plugpack and bridge rectifier DB1. The resulting unfiltered 16-17V rail from DB1 is then fed via diode D1 to a 2200mF filter capacitor and to pin 1 (Vin) of an LM2575 switching regulator, U5. This IC produces a regulated +5.8V rail for driving the LEDs. Schottky diodes D4 & D5 and the associated 47W resistor provide a simple charging circuit for a 4-cell NiMH or Nicad backup battery. It also allows the micro to be powered from the main +5.8V DC rail (via D4) when available and then automatically fall back to the backup supply when the main source fails. The added voltage drop across D4 (about 0.3V) also puts the microcontroller’s supply well below its absolute maximum rating of 6V. During a mains failure, the microcontroller continues to run and power is also available to the opto output and piezo buzzer but the power-hungry LED array is not powered. This allows maximum backup battery life and still preserves operation of the alarm functions. Mains synchronisation signal The unfiltered 100Hz signal from DB1 is also fed to the base of transistor Q7 to derive the mains synchronisation signal. This pulses Q7 on and off at a 100Hz rate, which in turn drives pin 4 (PB3) of the microcontroller (U3). The internal software in U3 processes this signal to derive the mains synchronisation signal for the 8MHz crystal oscillator. In effect, the clock relies on the mains for its long term siliconchip.com.au siliconchip.com.au June 2005  29 Fig.1: an ATMEGA8515-16 microcontroller (U3) is at the heart of the LED clock. It performs all the timekeeping functions and drives the LEDs via Darlington transistors Q1-Q5 and three ULN2003A Darlington transistor arrays (U1, U2 & U6). Fig.2: the circle LEDs are multiplexed by the microcontroller (U3), with Darlington transistors Q1-Q5 used to provide buffering and switching for the individual groups. Q1-Q5 also switch the digit LEDs. 30  Silicon Chip siliconchip.com.au siliconchip.com.au June 2005  31 Fig.3: the four digit displays in the centre of the clock each consist of 28 individual LEDs (ie, four LEDs to each digit segment) Fig.4: the parts layout for the top of the PC board. Install a shorting link on pins 2 & 3 of JP1 for 24-hour operation. accuracy but falls back to the crystal oscillator during a power failure. Alarm outputs When the alarm is triggered, the microcontroller switches its OC1B output (pin 29) high. This logic high then turns on transistor Q6 which sounds a small piezo buzzer and turns on the alarm indicator LED (LD70). 32  Silicon Chip At the same time, PD0 (pin 10) also goes high and this activates the optocoupler (OC1). As mentioned before, its output can then be used to control a low-voltage external device. Assembly Before starting the assembly, it’s a good idea to carefully inspect the supplied PC board and the parts lay- out diagram (Fig.4). In particular, pay special attention to the screw terminals mounted on the rear of the board – the supply and back-up terminals are labelled in copper and are hard to see under the solder mask. The PC board is double-sided with plated-through holes and a solder mask. This makes the assembly easy – there are no feed-through links to siliconchip.com.au Fig.5: the parts layout for the back of the PC board. The capacitors & choke L1 can be secured using hot-melt glue. install and you only have to solder the component leads on one side of the board. Note, however, that a few parts are mounted on the back of the board, which means that soldering takes place on the top (LED side) of the board. The main thing to watch out for with this project is the large number of posiliconchip.com.au larity sensitive parts – particularly the LEDs. And because the board is platedthrough, removing a part that’s already been soldered in will be extremely difficult and risks damaging the board. The rule is: check and double check before soldering. Apart from that, the assembly is quite straightforward and should only take a few hours. Begin the assembly by installing all the resistors on the board. To save any confusion, it’s best to install all those with the same value at a time. It’s also a good idea to install them all with the tolerance band facing the same way, as this makes it easier to check the assembly later on. Once the resistors are in, you can install the diodes, taking care to ensure June 2005  33 Above: the completed PC board is secured to the case using two M3 x 6mm screws and nuts, located at the 3-o’clock and 9-o’clock positions. This view shows the parts on the back of the PC board. Be sure to mount the two electrolytic capacitors exactly as shown, so that they clear the battery compartment. 34  Silicon Chip each device is installed in the correct location and is correctly orientated. D1 & D2 are 1N4007s, while D3-D5 are 1N5819s (don’t get them mixed up). That done, install the two BC547 transistors (Q6 & Q7), the bridge rectifier (DB1), the optocoupler (OC1) and the IC sockets. Push the transistors down onto the board as far as they will comfortably go before soldering their leads and watch the orientation of the bridge rectifier. The IC sockets should all be orientated so that their notched ends match the parts layout (this will make it easier when it comes to plugging the ICs in later on). Note that the socket for U6 (and the IC itself) faces in the opposite direction to the other sockets. Don’t fit the ICs into the socket just yet, though – that step comes later after the power supply has been tested. There’s just one wrinkle when it comes to fitting the socket for the microcontroller (U3) – the 6-way pin header for in-circuit programming mounts on the rear side of the board, directly under this socket. This pin header can be omitted in the vast majority of cases, since the microcontroller comes pre-programmed. If you do need the programming header, it will need to go in before the IC socket – just flip the board over and solder it in. The optocoupler (OC1) solders directly to the board. Be sure to install it with its notched end towards U3, as shown on Fig.4. Once it’s in, install the adjacent 3-pin header (JP1). Next, install the crystal (X1), followed by the five BD682 Darlington transistors (Q1-Q5). The latter are all installed by first bending their leads downwards through 90° about 4mm from their bodies, with the labels facing up. They are then installed so that they lie flat against the PC board, before soldering the leads. The LM2575T switching regulator (U5) is installed in similar fashion. As before, bend its leads down through 90° about 4mm from its body, then mount it in position and fasten its metal tab to the PC board using an M3 x 10mm screw and nut. That done, its leads can be soldered and trimmed in the usual manner. Note: don’t solder U5’s leads before bolting it to the PC board. If you do, the leads may be unduly stressed as the screw is tightened, which could fracture the PC board tracks. siliconchip.com.au Par t s Lis t 1 188mm-diameter double-sided PC board with black solder mask 1 clock case to suit PC board 1 330mH 3A ferrite choke (L1) 1 8MHz crystal (X1) 1 mini piezo buzzer (PC mount) 3 2-way PC-mount screw terminal blocks 4 AAA 1.2V rechargeable cells (NiMH or Nicad) 1 4 x AAA cell holder 3 miniature momentary contact PC-mount switches (SW1SW3) 3 M3 x 6mm screws 3 M3 nuts 1 3-way pin header 1 jumper shunt 1 black cable tie, 150 x 3mm 3 16-pin DIL IC sockets 1 40-pin IC socket The clear plastic bezel is fitted with a dark filter and simply clips into position via a couple of locating lugs. Once it’s in place, the filter is sandwiched between the bezel itself and the 5mm LEDs. The ceramic and monolithic capacitors are the next in line. Follow these with two 10mF tantalum capacitors. The latter are polarised, so make sure their positive leads go towards the top of the board. Installing the LEDs Now the real fun begins – you have to install no less than 176 LEDs. OK, so this job is a bit tedious but if you install them in groups of seven or eight, it won’t take long at all. As mentioned before, you really have to watch the orientation of the LEDs – put them in the wrong way around and the little blighters won’t work. The cathode lead is the shorter of the two (see Figs.1-3) and this corresponds to the flat edge shown on each LED outline in Fig.4. Note that, depending on the manu- facturer, each LED may actually have a flat side to also indicate the cathode. However, the LEDs supplied with the prototype were completely round, so don’t count on this. Basically, it’s just a case of pushing each group of LEDs all the way down onto the PC board and splaying their leads slightly to hold them in place for soldering. Be sure to double-check their orientation before actually applying the solder – get one (or more wrong) and it will be difficult to remove! Flip side Now for the parts on the reverse side of the PC board – see Fig.5. Flip the board over and install the three 2-way screw terminal blocks, followed by the piezo buzzer and the three pushbutton switches (SW1-SW3). Make sure the Where To Buy A Kit Of Parts This project was developed by Grantronics Pty Ltd for Jaycar Electronics and the design copyright is owned by Jaycar Electronics. A kit of parts is available from Jaycar for $A129.00 – Cat. KC-5404. This includes the clock case, the battery holder, the PC board and all on-board parts but does not include a plugpack supply or the rechargeable batteries. The 12VAC plugpack supply (Cat. MP-3020) is available for $22.95. siliconchip.com.au Semiconductors 3 ULN2003N Darlington transistor arrays (U1,U2,U6) 1 ATMEGA8515-16PC microcontroller – pre-programmed (U3) 1 LM2575T-ADJ switchmode regulator (U5) 1 PS2505-1 optocoupler (OC1) 5 BD682 PNP Darlington transistors (Q1-Q5) 2 BC547 NPN transistors (Q6,Q7) 1 WO4 bridge rectifier (DB1) 2 1N4007 silicon diodes (D1,D2) 3 1N5819 Schottky diodes (D3-D5) 164 high-brightness 3mm red LEDs 12 high-brightness 5mm red LEDs Capacitors 1 2200mF 25V PC-mount electrolytic 1 1000mF 10V PC-mount electrolytic 2 10mF 16V tantalum 3 100nF monolithic (code 104) 2 33pF NPO ceramic (code 33) Resistors (0.25W, 1%) 1 100kW 1 1.8kW 1 68kW 7 330W 1 6.8kW 14 220W 5 4.7kW 57 120W 1 3.3kW 1 47W June 2005  35 mount the electrolytic capacitors, the choke or the buzzer on the top of the board. They will interfere with the dark filter when the clear plastic bezel is later clipped into position if you do. Assuming everything is OK, switch off and install the chips into their sockets, taking care to ensure that they are all correctly orientated. Be careful when handling the chips, to avoid damage from static electricity. Don’t touch the pins and be sure to discharge yourself by touching an earthed metal object before touching the ICs. Note that U6 faces in the opposite direction to the others. Note also that pin 9 of U6 must NOT go into its corresponding socket pin. This pin can either be cut off using a pair of sidecutters or splayed out so that it runs down the outside of the socket– ie, this pin must NOT make any connection to the circuit (OK, we admit it – we made a mistake on the PC board). That done, connect the backup battery pack and re-apply power from the AC plugpack. The clock should immediately show 0:00 and the seconds LED should start chasing anti-clockwise. It’s then just a matter of setting the time and checking out all the functions using the pushbutton switches, as described earlier. After that, it’s simply a matter of securing the PC board inside the case using the M3 screws and nuts provided and clipping the front bezel into place. It’s up to you whether or not to use the dark filter material supplied. If you do decide to use it, it must be cut into a neat circle exactly 197mm in diameter, to fit inside the bezel. When the bezel is fitted, the filter is sandwiched between it and the 5mm LEDs and held firmly in position. Leave the filter out if you want the display to be really bright. Finally, if one or more LEDs fails to light, check its orientation. If a group of LEDs fails to light, check the corresponding BD682 driver transistor and its associated base bias resistors. SC Fit the stickers The rechargeable battery pack fits neatly in the battery compartment and can be secured using adhesive tape. Make sure it’s connected the right way around. buzzer goes in the right way around (ie, positive terminal to the left). That done, install the 2200mF and 1000mF electrolytic capacitors and the 330mH choke (L1). Note that, in both cases, the capacitor leads are bent down by 90°, so that their bodies lie flat against the PC board. Pay attention to the polarity of the capacitors and position them exactly as shown in Fig.5, so that they will clear the battery compartment A blob of hot-melt glue or epoxy adhesive can be used to secure them in position. Similarly, use hot-melt glue to secure the choke or you can secure it using a plastic cable tie – just loop the cable tie through the holes on either side. By the way, don’t be tempted to A number of adhesive labels are supplied with the kit and these indicate the switch functions and the connections to the screw terminal blocks. The ones for the screw terminal blocks are affixed directly to the PC board. Be sure to get these correct – if the 12V AC plugpack is connected to the back-up battery terminals, it will blow every chip on the board! The switch function labels are affixed to the back of the case, above the access slot. They are, from left to right: “Down”, “Mode” and “Up”. That’s it – the PC board assembly is complete and you’re now ready for the smoke test. Well, actually there shouldn’t be any smoke but you know what we mean! Testing Before fitting the ICs, it’s best to check that the supply regulator (U5) is working correctly. To do this, apply power from a 12VAC plugpack and check the voltage at the anode of D4 – you should get a reading of close to +5.8V. D4’s cathode should be at about +5.3V and this voltage should also be present on pin 40 of U3’s socket. The tab of the LM2575 regulator makes a convenient ground point. If you don’t get anything at D4’s anode, check the voltage at the cathode of D1 – you should get a reading of about 16-17V DC. Table 1: Resistor Colour Codes o o o o o o o o o o o   No. 1 1 1 5 1 1 7 14 57 1 36  Silicon Chip Value 100kW 68kW 6.8kW 4.7kW 3.3kW 1.8kW 330W 220W 120W 47W 4-Band Code (1%) brown black yellow brown blue grey orange brown blue grey red brown yellow violet red brown orange orange red brown brown grey red brown orange orange brown brown red red brown brown brown red brown brown yellow violet black brown 5-Band Code (1%) brown black black orange brown blue grey black red brown blue grey black brown brown yellow violet black brown brown orange orange black brown brown brown grey black brown brown orange orange black black brown red red black black brown brown red black black brown yellow violet black gold brown siliconchip.com.au THE AMATEUR SCIENTIST Two incredible CDs with over 1000 classic projects from the pages of Scientific American, covering every field of science... Arguably THE most IMPORTANT collection of scientific projects ever put together! This is version 2, Science Fair Edition from the pages of Scientific American. As well as specific project material, the CDs contain hints and tips by experienced amateur scientists, details on building science apparatus, a large database of chemicals and so much more. “A must for every science student, science teacher, science lab . . . or simply for those with an enquiring mind . . .” ONLY 49 $ 00 PLUS $7 Pack and Post within Australia (Overseas orders: please refer to Page 91 of this issue) Just a tiny selection of the incredible range of projects: ! Build a seismograph to study earthquakes ! Make soap bubbles that last for months ! Monitor the health of local streams ! Preserve biological specimens ! Build a carbon dioxide laser ! Grow bacteria cultures safely at home ! Build a ripple tank to study wave phenomena ! Discover how plants grow in low gravity ! Do strange experiments with sound ! Use a hot wire to study the crystal structure of steel ! Extract and purify DNA in your kitchen !Create a laser hologram ! Study variable stars like a pro ! Investigate vortexes in water ! Cultivate slime moulds ! Study the flight efficiency of soaring birds ! How to make an Electret ! Construct fluid lenses ! Raise butterflies as experimental animals ! Study the physics of spinning tops ! Build an apparatus for studying chaotic systems ! Detect metals in air, liquids, or solids ! Photograph an ant's brain and nervous system ! Use magnets to make fluids into solids ! Measure the metabolism of an insect . . . ! and many, many more (a thousand more, in fact!) See the review in SILICON CHIP, October 2004. . . or read on line at www.siliconchip.com.au HERE’S HOW TO ORDER YOUR COPY: BY MAIL:# BY INTERNET:^ BY PHONE:* (02) 9979 5644 9-4 Mon-Fri BY FAX:# (02) 9979 6503 24 Hours 7 Days <at> BY EMAIL:# silchip<at>siliconchip.com.au 24 Hours 7 Days PO Box 139, Collaroy NSW 2097 * Please have your credit card handy! # Don’t forget to include your name, address, phone no and credit card details. siliconchip.com.au 24 Hours 7 Days ^ You will be prompted for required information There’s also a handy order form on page 91 of this issue (SILICON CHIP Bookshop pages). Exclusive in SILICON Australia to: CHIP www.siliconchip.com.au siliconchip.com.au June 2005  37 Turn a fridge into a wine chiller! Or turn a freezer into a fridge! And save $$$$? That’s COOL! Design by Jim Rowe That’s the all-new COOLMASTER! 38  Silicon Chip siliconchip.com.au Enjoy a wine or two? Got a spare fridge? Why not convert it to a wine cooler, to hold your selected tipples at just the right temperature. Or how about converting a surplus chest freezer into a highly efficient refrigerator? M ORE AND MORE PEOPLE are buying a wine cooler for their home. It’s a nice idea – keep the wines on display but at just the right temperature. An ordinary fridge is too cold for wine storage but what if you could convert your spare fridge into a wine cooler? It could be much bigger than a typical bar fridge-style wine cooler and probably more efficient into the bargain. All you need is a precise and adjustable thermostat which will over-rule the existing fridge thermostat. That’s just what the CoolMaster does. In essence, the CoolMaster plugs into the wall power point and the fridge is plugged into it. Then the CoolMaster’s temperature sensor is installed in the fridge, with its two- wire lead brought out under the rubber door seal and it then over-rules the inbuilt thermostat. We’ve had quite a few requests for an electronic thermostat project, to convert a spare fridge into a wine cooler as simply and safely as possible. So that’s how the CoolMaster came to be developed. An article in the January/March 2005 issue of the Alternative Technolsiliconchip.com.au ogy Association’s “ReNew” magazine also featured a conversion of a chest type freezer into a very efficient fridge. Bingo! We realised that the CoolMaster could do exactly the same job and with tighter control than the abovementioned article. This is a very attractive concept, particularly if you have a remote homestead operating on solar power. A chest freezer has much better insulation than a standard fridge and has the benefit that the cold air does not fall out of it as you open the lid. Of course, you do not need to be in a remote location to want to save energy – anyone could employ the same idea to produce a highly efficient fridge at low cost. So there are two applications for the CoolMaster. To convert a fridge into a wine cooler the thermostat needs to maintain the internal temperature at around 9°C to 15°C (48-58°F), while to convert a chest freezer into a fridge it needs to maintain its temperature somewhere between about 4°C and 10°C. Another advantage of the CoolMaster is that if you ever want to run your fridge or freezer in its original mode, all you do is disconnect it from the CoolMaster. Simple! So that’s the story behind this new electronic thermostat project. It’s low in cost and easy to build. Virtually all of the parts, apart from the remote temperature sensor, fit on a small PC board which fits snugly inside a standard UB3-sized plastic utility box. The lead from the remote sensor plugs into one end of the box, while 240VAC mains power enters at the other end via a normal mains power cord. The power cord from the fridge or freezer then plugs into a 240VAC outlet on the lid, so the thermostat can control its operation. It’s that simple. It’s also quite safe – providing you don’t open the box and deliberately touch the mains wiring, of course. Most of the thermostat circuitry (including the remote sensor) runs from a 12V plugpack and is optically isolated from the 240VAC mains. So there’s no risk of shock from accidental contact with the temperature sensor wiring, for example. How it works Fig.1 shows the circuit of the Cool­ Master and its operation is quite straightforward. The heart of the circuit is the remote temperature sensor June 2005  39 +12V DC INPUT D1 1N4004 A REG1 7809 K CON1 GND 2200 µF 16V 100 µF 16V 6.8k 10k A 100nF SET TEMP λ 2 2.2nF 2 3.0k GND TEMPERATURE SENSOR (IN FRIDGE OR FREEZER) 1nF VR1 500Ω 3 LED1 8 6 IC1 LM311 1 5 A 4 47nF 250V X2 Ain TRIAC1 BT137F A2 G λ TS1 LM335Z MAINS EARTH LED LM335Z E K 3.5mm PLUG BROWN ADJ – A COOLMASTER FRIDGE/FREEZER TEMPERATURE CONTROLLER SC N CON2 RED + 2005 N OUTLET TO FRIDGE OR FREEZER 680Ω 4 39Ω 10nF 250V X2 Aout A1 K 7 A 240V AC INPUT A + – 1 K 470Ω IC2 6 MOC3021 33k VR2 5k OUT IN 390Ω 3.3k 100Ω 1N4004 7809 GND WARNING: COMPONENTS & WIRING IN THIS AREA ARE AT 240V MAINS POTENTIAL WHEN THE CIRCUIT IS OPERATING. CONTACT MAY BE LETHAL! +9V OUT IN A1 A2 G BT137F Fig.1: the mains area of the circuit (shown in pink) is isolated from the low-voltage section. But make sure you don’t plug the CoolMaster into a power point while the cover is off: it’s dangerous! TS1, an LM335Z device specifically designed for temperature sensing. The LM335Z acts like a special kind of zener diode, in which its voltage drop is not fixed but varies linearly and quite accurately with its temperature. In fact, its voltage drop is directly proportional to absolute temperature, having a value of 0V at 0K (-273°C) and rising linearly by 10mV for every Kelvin (or °C) rise in temperature. This is shown in the graph of Fig.2. So at a temperature of 0°C (273K), the voltage drop of the LM335Z is very close to 2.73V. Similarly, at 16°C (289K), it rises to 2.89V. It’s this change in voltage that we use to precisely control the temperature of our fridge or freezer, by comparing the sensor’s voltage with a preset reference voltage. Sensor TS1 is connected between the inverting input (pin 3) of IC1 (an LM311 comparator) and ground (0V). A 10kW resistor also connects from pin 3 to the +9V rail, to provide the sensor with a small bias current. The voltage at pin 3 of the comparator is therefore the voltage across TS1 and is directly proportional to the temperature in the fridge or freezer cabinet. To provide the comparator with a preset “set temperature” reference voltage, we connect its non-inverting (+) input (pin 2) to an adjustable voltage divider across the regulated +9V supply rail. Multi-turn trimpot VR1 forms part of the lower leg of the voltage divider, 2.90 Fig.2: this chart shows the relationship between the temperature and the output voltage of the LM335Z sensor. This information can be used to help set up the CoolMaster. 2.89 2.88 SENSOR VOLTAGE 2.87 2.86 2.85 2.84 2.83 2.82 2.81 2.80 2.79 2.78 2.77 4 5 6 7 8 9 10 11 12 13 14 TEMPERATURE – DEGREES CELSIUS 40  Silicon Chip 15 16 allowing the voltage at pin 2 to be adjusted to any value between about 2.75V and 3.06V. These voltage limits correspond to a sensor temperature range of 2.5° to 33°C, so it’s easy to set the thermostat to maintain the fridge or freezer temperature anywhere in this range. The maximum temperature of 33°C does seem a little high (hot!) since the normal wine cooler temperature is around 15°C but since VR1 is a multiturn trimpot which only has to be set once, it is not really a problem. While ever the temperature inside the fridge or freezer remains lower than the temperature set by VR1, the voltage drop across TS1 will be lower than the preset voltage applied to pin 2 of IC1. As a result, the IC1’s output (pin 7) will be high (ie, +9V) and both LED1 and the input LED of the MOC3021 optocoupler (IC2) will be off. But if the temperature inside the fridge/freezer rises to the set temperature level, the voltage drop across TS1 (at pin 3 of IC1) will match the voltage on pin 2, and the comparator output will swing low (0V) to pull current through LED1 and the optocoupler’s LED. LED1 will turn on and the Triac inside the MOC3021 will also be switched on, triggering Triac 1 into conduction as well. This will switch on power to the compressor unit in siliconchip.com.au NYLON SCREWS & SPACERS AT ALL FOUR MOUNTING POSITIONS – SEE FIG.4 CORD GRIP GROMMET 12V IN CON1 REZEERF/EGDIRF LORTNOC PMET 47nF 250VAC 3.0k BROWN WIRE CABLE TIE CABLE TIE BLUE WIRE N A 10nF 250VAC MOC 3021 BT137F 33k 3.3k IC1 LM311 100nF TRIAC1 15060101 VR1 500Ω 2.2nF SOCKET FOR LEAD FROM TEMP SENSOR TS1 1nF CON2 6.8k 10k GND IC2 100Ω GREEN/ YELLOW WIRE Aout 390Ω 39Ω 4004 D1 Ain 470Ω REG1 7809 100 µF BROWN WIRE 2200 µF VR2 5k 680Ω WARNING! ALL PARTS INSIDE THE RED DOTTED LINE OPERATE AT MAINS POTENTIAL. DO NOT TOUCH ANY PART OF THIS CIRCUIT WHEN THE UNIT IS PLUGGED INTO A MAINS OUTLET K A E LED1 REAR OF MAINS SOCKET INSULATE BOTH LED LEADS WITH HEATSHRINK TUBING Fig.3: this combined component overlay and wiring diagram should be all you need to put the CoolMaster together. Secure any mains wires together with cable ties – just in case. Remember that components and tracks inside the dotted red line above are at mains potential when operating – never connect power with the case open. the fridge/freezer, causing it to cool things down again. It runs the compressor only long enough to bring the temperature just below the set level. Feedback We prevent the circuit from oscillating or ‘hunting’ by giving it a small amount of positive feedback, via the 100W resistor in series with the optocoupler and LED1, and the 33kW resistor connecting back to the balance input at pin 5. This lowers the voltage at pin 5 when the LED and Triac are on and means the input voltage from TS1 must drop down to a level slightly lower than the voltage at pin 2, before the comparator will turn off again. In other words, we give it a small amount of “hysteresis”. Trimpot VR2 is used to adjust the balance of IC1, although with most LM311s it can be left in the centre position. The 390W and 470W resistors and the 47nF capacitor are used to ensure that Triac 1 is switched cleanly on and off by the Triac section inside the optocoupler. On the other hand, the 39W resistor and 10nF capacitor across Triac 1 are used to protect it from mistriggering due to ‘spikes’ which may be generated by the inductive load of the fridge/freezer compressor motor. These parts, along with the Triac itself, siliconchip.com.au are at 240VAC mains potential when the thermostat is working. All of the low voltage part of the circuit operates from 9V DC, derived by regulator REG1 from the 12V DC input via CON1 and protection diode D1. The 12V input can come from either a 12V battery or a plugpack supply. The current drain is quite low (about 11mA), so you can use the smallest available 12V DC plugpack. Alternatively, you could use a 9V AC plugpack. This will be rectified by diode D1 and filtered by the 2200mF 16V capacitor. Construction First, a warning: to ensure safety, you must use a plastic case for this project. In addition, because some of the circuitry operates at mains potential (ie, 240V AC), you must mount the PC board on Nylon spacers and secure it inside the case (at the top) using Nylon screws. You must also keep the mains wiring short and bind the Active, Neutral and Earth leads together in several places using cable ties, including one tie directly behind the mains socket and another close to the “Ain” and “Aout” terminals on the PC board. That way, if a mains wire comes adrift, it cannot move and contact other parts. As a further precaution, you should also insulate both leads of the LED using heatshrink sleeving or some other This photo of the assembled PC board shows where everything goes. Be sure to insulate the LED leads using heatshrink sleeving. INSULATE LED LEADS WITH HEATSHRINK TUBING June 2005  41 hand hole (marked A on Fig.3) and the shorter cathode lead through the other hole (K). Pass them down as far as they will go so that the LED body is 15mm above the board and solder them to the board pads underneath. Make sure that the LED leads are completely insulated, with no gaps at either end. Cover the ends with blobs of silicone sealant if necessary. Finally, bend both leads forward by 90° at a point 10mm above the board, so the LED will be ready to protrude slightly through the hole in the front of the box when it’s all assembled later. Your board assembly should now be complete. This view shows everything assembled in the case, immediately before the lid was screwed on. Note that Nylon screws must be used to secure the PC board (not metal as used in the prototype). suitable plastic sleeving and smear the ends with silicone sealant. All of the components used in the CoolMaster circuit except for the remote sensor TS1 and its plug and socket are mounted on a small PC board. This measures 76 x 57mm and is coded 10106051. As shown in Fig.3, all the low voltage circuitry is at one end of the board and the “live” circuitry at the other, with the optocoupler IC2 linking them across the isolating gap which separates the two. Begin wiring up the PC board by fitting the two terminal pins. These go down near the lower left-hand corner of the board, ready for the wires from CON2 later on. Next, fit DC input connector CON1, which goes at upper left. It’s a good idea to fit this early on, because you may find that the board holes need to be elongated slightly to accept the connector mounting lugs, using a jeweller’s needle file. Now fit the various resistors, making sure you fit each one in its correct position. If in doubt, check their values first with a DMM. Then fit the two trimpots, the smaller non-polarised capacitors and the two 250VAC-rated capacitors (which are non-polarised). The last capacitors to be installed are the two electrolytics; take special care with these as they are polarised. Make sure you follow the diagram carefully for their orientation, or you’ll strike trouble later. Take the same care with the semiconductors, starting with diode D1. Follow this with IC1, IC2, REG1 and 42  Silicon Chip finally the Triac. Note that REG1 and the Triac are both in TO-220 packages (don’t mix them up!). They are both mounted horizontally, with their leads bent down 90° some 6mm from their bodies. Both devices are secured to the board using an M3 x 6mm machine screw and nut, passing through the holes provided in their mounting tabs and the board. In the case of the Triac there’s also a 19mm square heatsink between the Triac tab and the board, to make sure the Triac runs cool even during long periods of operation in hot weather. DO NOT substitute for the Triac. You must use an insulated tab device (otherwise the heatsink will be at mains potential). The next step is to fit LED1, which is initially mounted with its leads straight and vertical. First, cut two 15mm-long lengths of plastic or heatshrink sleeving and fit these to insulate the leads. That done, fit the LED in position with its longer anode lead passing down through the right- Wiring the sensor Next we need to wire up the LM335Z temperature sensor and the steps for this are shown in Fig.6. Cut a 60mm length from one end of the two-core ribbon cable that you’ll be using for the remote sensor lead and bare about 4mm at each end of both wires. Solder one end of the two wires to the terminal pins on the end of the PC board, just above VR1. Solder the red wire to the lower pin and the brown wire to the upper pin, as shown in Fig.3. Mains wiring Next, cut a 75mm length off the free (ie, non-plug) end of the mains cord and remove the outer sleeve so the three insulated wires are exposed. Discard the blue and green/yellow wires but bare the ends of the brown wire by about 4mm at one end and 10mm at the other. This will become the “Active” wire connecting the output of the PC board to the Active pin of the mains socket (on the lid). Now carefully push the end bared by only 4mm through the hole in the Extra close-up view of the mains wiring, Note the cable ties around the mains wires themselves which will secure the “bitey” bits in this area of the case should they somehow come adrift. Yes, it’s unlikely . . . but so was the Titanic’s iceberg. siliconchip.com.au 30 5mm DIA. 25 15 10 15 Fig.4: here’s how to secure the PC board to the case. You must use Nylon spacers and screws where specified, to ensure safety. board labelled “Aout” and solder it to the copper pad underneath. For the present, just tin the wire at the 10mm bared end. Now remove another 60mm length of outer sleeving from the free end of the mains cord, to expose the same length of the three insulated wires inside. Take care that you don’t nick any of the insulation on the wires inside. Then bare 4mm at the end of the brown wire and 10mm at the ends of the other two wires. Carefully tin the ends of the longer bared wires but not the end of the brown wire at this stage. Next, fit the cord-grip grommet to the outer sleeve of the mains cord, at a point which leaves about 15mm of sleeving before the removed end. Then push the wires at the end of the cord through the large hole in the end of the box (from outside), align the flat sides of the grommet halves with the flats on the hole sides, and finally push both the cord and grommet into the hole until it all clicks into place. Give the mains cord a firm tug from the outside to ensure it is properly locked in. Now carefully push the bared end of the cord’s brown wire through the remaining “Ain” hole in the end of the PC board and solder it to the pad underneath. Next, secure the four M3 x 6.3mm tapped Nylon spacers to the bottom of the box using the four countersunkhead screws provided. That done, you can lower the board down into the box until it’s sitting on the spacers and fasten it to them using four M3 x 6mm Nylon screws with Nylon nuts used as spacers – see Fig.4. You may have to bend the LED leads inwards a little to lower the board into place but once it is screwed down you should then be able to bend the leads so the LED body protrudes through its siliconchip.com.au 25 22 LID 65 19 3.5mm DIA. BOX FRONT 33 20 18 10 6mm DIA. 26 27 18 3.5mm DIA. 14 LEFT-HAND END RIGHT-HAND END 26 24 8mm DIA. BOX REAR Fig.5: the box drilling details. Note that this is reproduced 80% “life size”. We suggest you photocopy this at 125% if you want to use it as a template. matching hole in the side of the box. Now you can fit the 3.5mm jack socket into the 6mm hole in the centre of the left-hand end of the box and tighten its nut to hold it in place. Then you can solder the ends of the two short wires connected to the board’s PC terminal pins to its two main connection lugs, as shown in the wiring diagram. Note that the brown wire goes to the side lug and the red wire to the end lug furthest from it. Next you should fit the mains outlet socket to the box lid. This is done by first removing the screw from the centre of the outlet’s front plate, which allows the plate to be lifted off. That done, you then hold the rear part of the socket up behind the large hole in the box lid, with the earth connection clip at the bottom. The front June 2005  43 Parts List – CoolMaster Fridge/Freezer Controller 1 PC board, code 10106051, 76 x 57mm 1 plastic jiffy box, UB3 size (130 x 67 x 44mm), grey 1 small U-shaped heatsink, 19 x 19 x 9.5mm (6073B type) 1 2.5mm DC input socket, PC board mounting (CON1) 1 3.5mm mono jack socket, panel mounting type (CON2) 1 3.5mm mono jack plug 1 3-pin mains outlet, flush panel mounting type 1 cord-grip grommet 1 2m 3-core mains cord & 3-pin plug 4 M3 x 6.3mm tapped Nylon spacers 4 M3 x 6mm Nylon screws 4 M3 Nylon nuts 4 M3 x 6mm countersink-head machine screws 2 M3 x 6mm machine screws 4 M3 nuts and star lockwashers 2 PC board pins, 1mm diameter 1 2m length of 2-conductor ribbon cable 2 50mm lengths of 2.5mm heatshrink sleeving 1 50mm length of 5.0mm heatshrink sleeving 1 25 x 50mm piece of 3mm aluminium sheet plate can then be mated with it from the front of the lid and the screw used to fasten them together again. Once the socket is mounted on the lid, bring them close to the box. This will allow you to connect the free ends of the brown wire from the PC board and the blue and green/yellow wires 1 30 x 10mm piece of 1mm aluminium sheet 2 M3 x 9mm countersink-head machine screws Semiconductors 1 LM311 comparator (IC1) 1 MOC3021 optocoupler (IC2) 1 BT137F 600V/8A Triac, insulated tab type (do not substitute) 1 7809 regulator (REG1) 1 3mm red LED (LED1) 1 1N4004 diode (D1) Capacitors 1 2200mF 16V RB electrolytic 1 100mF 16V RB electrolytic 1 47nF 275VAC X2 class metallised polypropylene 1 10nF 275VAC X2 class metallised polypropylene 1 100nF MKT metallised polyester 1 2.2nF greencap 1 1nF greencap Resistors (0.25W 1%) 1 33kW 1 10kW 1 6.8kW 1 3.3kW 1 3.0kW 1 680W 1 470W 1 390W 1 100W 1 39W 1 500W multiturn cermet trimpot (VR1) 1 5kW mini horizontal trimpot (VR2) from the mains cord to their respective receptacles on the mains socket, as shown in the wiring diagram. The brown wire goes to the socket receptacle marked A, the blue wire to that marked N and the green/yellow wire to the one marked E. You need to unscrew each recep- Capacitor Codes Value IEC Code EIA Code 100nF (0.1mF) 100n 104 47nF (0.047mF) 47n 473 10nF (0.01mF) 10n 103 2.2nF 2n2 222 1nF 1n0 102 tacle’s fastening screw a few turns before pushing the wire end inside, and then screw them up tightly again to make sure each wire is held in place securely. Finally, install the cable ties to secure the Active, Neutral and Earth leads to each other – see photos. Making the remote sensor The final stage in building the project is to make up the remote temperature sensor and its lead. You’ll find this is again quite easy if you use the step-by-step diagram as a guide. As you can see, the first step is to clip off the unwanted third lead of the LM335Z sensor, and then solder the ends of the 2-core ribbon cable wires to the other two leads after slipping 25mm lengths of 2.5mm diameter heatshrink sleeving over each one. After the solder cools and you are happy that both joints are good, the sleeves are then moved up until they butt hard against the body of the LM335Z, after which they are heated (a hair dryer on high is usually hot enough) to shrink them in place (step 2). Then a 30mm length of 5mm dia­ meter heatshrink sleeving is slipped along the cable and over the other sleeves, and heated in turn to shrink it in place as well (step 3). Prepare the sensor’s heatsink assembly by drilling two 3.5mm holes on the centre line of the 50 x 25mm Resistor Colour Codes o o o o o o o o o o o No. Value 1 33kW 1 10kW 1 6.8kW 1 3.3kW 1 3.0kW 1 2.2kW 1 680W 1 470W 1 390W 1 100W 1   39W 44  Silicon Chip 4-Band Code (1%) orange orange orange brown brown black orange brown blue grey red brown orange orange red brown orange black red brown red red red brown blue grey brown brown yellow purple brown brown orange white brown brown brown black brown brown orange white black brown 5-Band Code (1%) orange orange black red brown brown black black red brown blue grey black brown brown orange orange black brown brown orange black black brown brown red red black brown brown blue grey black black brown yellow purple black black brown orange white black black brown brown black black black brown orange white black gold brown siliconchip.com.au aluminium plate. They should be 18mm apart and the bottom of each hole should be counter­sunk to accept countersink-head screws. Next make the 30 x 10mm piece of 1mm aluminium into a clamp piece, by bending its central 8mm section into a half-round shape to fit over the LM335Z body snugly. After this drill 3.5mm holes in the flat ends of this clamp piece, 18mm apart again to match the holes in the larger plate. You should then be able to assemble the probe with the LM335Z clamped to the top of the plate (flat side down) and the screws tightened down using M3 nuts and star lockwashers (step 4). Complete the sensor assembly by fitting the 3.5mm mono jack plug to the other end of the two-core ribbon cable, connecting the red wire to the ‘tip’ lug and the brown wire to the ‘sleeve’ lug (step 5). Fig.6: How To Wire The Sensor – Step-By-Step LM335Z (FLAT SIDE DOWN) BROWN WIRE TO THIS LEAD CUT ADJ LEAD SHORT RED WIRE TO CENTRE LEAD 2 x 25mm LENGTHS OF 2.5mm HEATSHRINK 30mm LENGTH OF 5mm DIA HEATSHRINK 3-METRE LENGTH OF 2-CORE RIBBON CABLE 1 SOLDER RIBBON CABLE WIRES TO TEMP SENSOR LEADS 2 SLIDE HEATSHRINK SLEEVES UP AND HEAT TO SHRINK 3 FIT LARGER SLEEVE AND HEAT TO SHRINK OVER ALL LEADS M3 x 9mm LONG COUNTERSINK HEAD SCREWS WITH STAR LOCKWASHERS AND M3 NUTS Setting it up There isn’t much involved in setting up the thermostat for use. Balance trimpot VR2 can be set to the centre of its range, as shown in the photo. Then if you know the temperature you want to set the thermostat to maintain, it’s a matter of adjusting trimpot VR1 to produce the corresponding voltage level at pin 2 of IC1. This can be done by trial and error once the project is finished and working but if you have a digital multimeter it can also be done before the case is closed up (but before the mains cord is connected to the power, of course). If you want to do this, plug the 12V DC cable from your plugpack into CON2 at the back of the box but DO NOT plug the thermostat’s power cord into a power point. Connect the leads of your DMM (set to a low DC voltage range) between pins 2 & 4 of IC1. Read the voltage, which should be somewhere between 2.75V and 3.05V. Now all you have to do is look up the voltage level for the temperature you want from the small graph in this article (Fig.2) and adjust VR1 until the DMM reading changes to this value. After this you can dress the three power outlet wires so they allow the lid and outlet to be lowered down into the box, until the lid is sitting squarely on the top. Then the box assembly is completed by fitting the four 16mm long self-tapping screws provided, to hold siliconchip.com.au 4 CLAMP SENSOR ASSEMBLY TO 25 x 50mm ALUMINIUM HEATSINK PLATE everything together. You might also want to fit the small rubber bungs to the screw holes after the screws are in place, to produce a neat result. All that remains now is to mount the remote sensor inside the fridge or freezer cabinet, attaching its heatsink plate to the side of the cabinet using two short lengths of “gaffer” tape. Some double-sided foam pads may also work but remember that the inside of the cabinet is often moist. Then you can run its ribbon cable outside, holding it down with further strips of gaffer tape so it will pass neatly under the rubber door seal when the door is closed. If you mount the thermostat box on the wall just behind the fridge/freezer, the plug on the end of the ribbon cable can be plugged into CON2 on the end of the box to complete the job. Now you can unplug the fridge/ freezer’s power cord from its original GPO (power point) and plug it instead into the outlet on the top of the thermostat. Then when you plug 5 FIT 3.5mm JACK PLUG TO OTHER END OF RIBBON CABLE (RED WIRE TO TIP) the thermostat’s own mains cord into the original GPO, the complete system will begin working. If you want to make sure that the thermostat is holding the fridge/ freez­er to the temperature you want, this can be done quite easily using a thermometer placed inside the cabinet. Alternatively, you can monitor the sensor voltage across the lugs of the ribbon cable plug and verify that the voltage cycles up and down but is centred on the value for the desired temperature (as shown in the graph). If you need to adjust the average temperature up or down, this is done quite easily by adjusting trimpot VR1 using a small screwdriver. That’s the reason for the small hole in the leftSC hand end of the box. Kit Availability This kit has been sponsored by Jaycar Electronics, who own the copyright. Kits (Cat. KC-5413) will be available from Jaycar. June 2005  45 Salvage It! BY JULIAN EDGAR A voltmeter for almost nothing Want a really cheap voltmeter? Here’s how to adapt a VU meter that’s been scrounged from an old audio cassette deck. R ECENTLY, IN THIS column, we’ve covered both a very cheap leadacid battery charger (made from a plugpack and a resistor) and a variable output switchmode 12V power supply (made from a phone charger). In both cases, it’s useful to also have a meter displaying voltage. In the case of the battery charger, a voltmeter lets you monitor the battery’s voltage as it charges, while in the power supply, it lets you monitor the output voltage. There’s a heap of other uses for a voltmeter as well – especially when you realise that this meter will cost you next to nothing. And it’s easy to customise the scale and the voltage range over which the meter works. Want some more possible uses? Well, in a model railway layout, you could use the meter to display the voltage being fed to the lighting – but instead of having “volts” marked on the scale, you could have “dusk”, “night” and “day” ranges marked. Fig.1: a VU meter is a very sensitive instrument. It can be adapted to measure a wide variety of voltages by installing 100kW a variable resistor in series with the supply voltage. This allows you to easily adjust the Full Scale Deflection to match the peak voltage you need to measure. 46  Silicon Chip Another use is in battery-powered equipment. Because the meter draws very little power, it could be used in many applications to permanently display the battery voltage. That way, you’ll always know if you’ve got a battery that’s nearing the end of it charge (or its life). The Components You’ll need only two components, as well as access to a computer, just about any image manipulation program, a scanner and a printer. You’ll also temporarily need a plugpack, a 10kW pot and a multimeter and to do the calibration, you’ll temporarily.) The two electronic components required are: (1) an analog VU meter from a discarded audio cassette deck; and (2) a 100kW multi-turn trimpot, used here as a variable resistor. Old cassette decks with large illuminated VU meters turn up all the time in garage sales, at the tip and during kerbside collections. It is extremely rare for the VU meters to be dead, so you can be fairly safe in collecting any old cassette deck for this purpose. Try to obtain a deck that has two separate meters (one for each stereo channel), rather than one that has them combined into a single display. VU meters are typically moving coil voltmeters that have a very high sensitivity. This means that it takes very little voltage to move the needle across the full scale – typically, just 0.3–0.4V. Their coil resistance is very high, being around 600-700W. Plug these figures into Ohm’s Law (ie, I = V/R) and you’ll find that the meter current is only about 0.5 Here a multi-turn trimpot has been used as the series variable resistor. This makes calibrating the meter easy. milliamps (0.5mA) for full-scale deflection! Building It If you need to measure a voltage that rises only to about 0.4V, all you need do is connect the meter straight across the supply. However, it’s much more likely that you’ll want to measure a peak voltage of 5V, 12V or even 24V. Fortunately, it’s very easy to decrease the sensitivity of the meter – just wire a variable resistor in series with the meter, as shown in Fig.1. But how do you make the scale match the readings you want the meter to show? Most VU meters use a non-linear movement – that is, the needle moves less for a given voltage increment at the top end of the scale than it does towards the bottom. This means that you can either position the markings closer together as you move up the meter scale or you can space the markings evenly and jump further between numbers. We chose to do the latter. You can use your PC and printer to make the new scale. You could scan in the original scale and modify it but in practice, it’s best to start with the siliconchip.com.au scale from another instrument. The meters shown here use a scale that was originally scanned in from an old speedo. Once you have the arc and the increments, you can use the software to delete the numbers and any other markings you don’t want. That done, measure the width of the scale on the meter and then size the on-screen version to match this and print it out – ie, without any numbers on it. Next, carefully remove the original scale (most meters are held together with tape, with the scale glued in place) and temporarily place your “un-numbered” scale behind the pointer. To provide a variable calibration voltage, use the approach shown in Fig.2. This involves wiring a 10kW potentiometer across the output of a discarded plugpack. By adjusting the pot, you can vary the calibration voltage from 0V up to the maximum voltage provided by the plugpack. The multimeter is included so that you can measure the voltage being fed to the VU meter. So how do you perform the calibration? First, adjust the 100kW trimpot so that the most commonly read maximum voltage is towards the end of the scale. After you’ve set this, don’t touch the trimpot again. Next, alter the input voltage, measure it with the multimeter and work out what each of the other graduations on the modified meter scale should show. Be sure to round off the voltages to the nearest whole volt. For example, on one of the meters shown here, the scale goes: 4, 7, 11, 14, 18, 25, 34V. Once you’ve figured it all out, use On the right is one of a pair of VU meters removed from an old cassette deck. At left is its modified brother, recalibrated and rescaled as a voltmeter reading up to 34V. Fig.2: wiring a 10kW pot across a plugpack provides a variable voltage source, allowing you to calibrate the scale. The multimeter shows what the readings on the new meter scale should be. your graphics software to put the numbers on the scale, along with any other writing you want. Finally, print it out on gloss paper, cut it to shape and stick it in place. Using It Using the meter is as simple as connecting it (and its series 100kW trimpot) across the voltage source that you want to monitor. Note that if the meter needs to be used at night, it’s easy to illuminate the scale. In fact, the cassette deck that you scrounged the meter from probably also had a suitable bulb in it. Make sure that it has the correct voltage rating for your SC application though. Rat It Before You Chuck It! Hmm, “JE instruments” . . . gee, that sounds like a good brand. When you make your own scales, you can put anything you like on them! siliconchip.com.au 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 easily be salvaged from goods commonly being thrown away, we’d love to hear from you. Perhaps you use the pressure switch from a washing machine to control a pump. Or maybe you have a use for the highquality bearings from VCR heads. Or perhaps you’ve found how the guts of a cassette player can be easily turned into a metal detector. (Well, we made the last one up but you get the idea . . .) If you have some practical ideas, write in and tell us! June 2005  47 SERVICEMAN'S LOG Every storm has a silver lining There’s no doubt about it – an electrical storm is good for business. But I never cease to be amazed at the sometimes seemingly random damage that occurs to a TV set. Mr Patrick brought in his dead NEC FS-68T90 (Daewoo CP-785A chassis) just after an electrical storm the night before. As usual, the fuse hadn’t blown and most of the set looked perfectly OK. Powering it up, everything seemed correct except for a low 5V rail. By disconnecting the circuits bit by bit, I soon found that the tuner (Philips) was drawing excess current due to an internal short. Replacing it removed this short and restored the 5V rail. However, there was still no EHT because there was no horizontal drive waveform from the TDA9365 jungle IC. The voltages all looked correct apart from the ones which were dependent on the line output stage working – even the crystal frequency was spot-on. However, the DC voltage on the I2C SCL clock pulse was low, with no data Items Covered This Month • NEC FS-68T90 TV set (Daewoo CP-785A chassis) • Sony TA-EX70 AV Centre Control Amplifier • Sony KP-EF41SN (RG-2 chassis) projection TV • • Denon UDM50 stereo system • • • Loewe 84-100 TV set (Q2100 Chassis) JNL5103 TV set Sharp CX6N5 TV set Blaupunkt IS70-33 TV set 48  Silicon Chip activity showing on the CRO. Once again, by progressively disconnecting all the ICs the SCL pulse went to, the Sound Micron microprocessor IC601MSP3451D was determined to be the culprit. A new one restored almost everything in the set, with good picture and sound. What still didn’t work was the install menu and the service manual didn’t give much of a clue on this. NEC Technical Support thankfully deduced that the set was locked into the “HOTEL” mode. This function is to protect hotel TV installations from the prying hands of inquisitive guests. To release it, you have to press “Delete”, “Move”, “Skip” and “Operate”. Finally, to access the Service Mode, you must first select program 91 and set “Sharpness” to minimum, then very quickly press “Red”, “Green” and “Menu” in turn, then “OK”. In summary, it looked as though Mr Patrick’s TV had suffered a lightning strike via the outside aerial. This damaged the tuner, before sending a transient back up the SCL clock pulse line. Under the circumstances, it could have been much worse. Master tech! A very confident Mr Allen brought in his 1996 Sony TA-EX70 AV Centre Control Amplifier. Apparently, an accident had caused heat to be applied to the front escutcheon, resulting in no display. He had already diagnosed the problem and priced the parts required, namely the fluoro display and driver IC – IC551 (FL501). All he wanted was us (the dummies) to fit them – you know, the easy bit! The job was given to one of our new technicians who did a very professional job of replacing these parts. However, he was very disappointed to find that he still didn’t have a display – especially as there wasn’t much else in the circuit. The -28V and +5V rails were present and the CRO showed there was digital noise on the data line plus 5V on the reset line. As a result, it was decided that John, our very competent senior audio technician, would take a look at the problem. He too could see nothing wrong with the unit and suspected a “horrible” digital problem with the microprocessor. That was when one of our TV technicians said he would have a look. The others all dismissed him as a mere TV man – what could he possibly know about audio equipment? However, he surprised them all by fixing the problem in five minutes flat! He deduced that despite no voltages being shown on the circuit of an equivalent model, the fluoro display filament voltage was low at 1.5V AC. In fact, he had expected it to read somewhere around 4-5V. In practice, this filament is fed via an unusual arrangement of four parallel resistors and one series capacitor in each leg from a mains transformer (T901). He found these on the intermediate Main Board and could see that this board had become discoloured due to heat from these components. This in turn indicated that the two series 100mF 25V electrolytic capacitors (C971 & C972) had dried out, reducing their values to just 3mF and 8mF respectively. Replacing them increased the filament voltage and the fluoro resumed working. John was so impressed that he now calls my Teutonic friend “Master Tech”. God knows his ego doesn’t need this extra praise! Sony projection TV I have a problem with rear projection TVs and that involves logistics. In the main, they are just too big, too siliconchip.com.au awkward and too difficult to repair in comfort – not to mention extremely expensive. Besides that, until just recently, I the picture was poor unless you were directly in front of the screen. Recently though, new technology has improved this out of sight. Nevertheless, you always need no less than two and possibly three people to move the item to a special trolley and to transport it. You then need a large bench to place it on, before trying to disassemble it and reach impossible areas to make the necessary measurements. Add to these problems expensive and sometimes difficult-toget service manuals and you can see why I’m hardly ever thrilled about servicing projection TVs. So having stated where I stand on these monsters, I also have to state that I unfortunately often get involved in servicing them. For example, just recently, my mechanic’s 1998 Sony KP-EF41SN (RG-2 chassis) carked it during yet another thunderstorm (they’re good for business, those thunderstorms). Now it has come to my attention that some people like to whinge about how much TV techs charge but compared to mechanics (and plumbers), I reckon we’re pretty tame! In fact, I was doing my best to earn a few “brownie points” for me and my wheels when I decided to take this project on. Anyway, this set’s power supply board G just wasn’t supplying the necessary volts. As a result, I removed the board and did some DC checks on what looked like a brand new module. The first thing I found was that fusible resistor R6033 (0.1W, 1W) was open circuit. This feeds 292V to two pairs of FETs and Q6015 and Q6014 (IRF1744G-LF SW) were both short circuit. I replaced these, along with the driver IC (IC6007, IR2112) and 20V zener diodes D6046 and D6047. For good measure, I also replaced C6030 (0.039mF 800V), as this often causes a “no-go” situation when it goes open circuit. In order to test it on the bench, you have to bypass the mains power switch by connecting pin 4 of plug CN6006-1 to pin 5 of plug CN6007-1 (be careful). Then, to turn it on, you have to apply 7V from pin 1 of plug CN6008 to pin 3 (Power Control). I used a 100W globe on the +135V rail and pins 1 & 2 of CN6011 for ground. Everything else checked out OK so I refitted the module and prayed before switching on. Fortunately, everything was “cool” – that was all that was wrong and the set now worked flawlessly. Select your microcontroller kit and get started... From $295* RCM3400 Fax a copy of this ad and receive a 5% discount on your order! Feature rich, compiler, editor & debugger with royalty free TCP/IP stack • Prices exclude GST and delivery charges. Tel: + 61 2 9906 6988 Fax: + 61 2 9906 7145 www.dominion.net.au 4007 Ozitronics www.ozitronics.com Tel: (03) 9434 3806 Fax: (03) 9011 6220 Email: sales2005<at>ozitronics.com 4-Channel Temperature Data Logger Continuously logs up to 4 sensors via serial port (one sensor supplied). °C or °F. PCB just K14538x38mm. Powered by serial port. Extra DS1820 sensor - $13.20 $37.95 40 Sec. Message Recorder Record multiple messages as will fit in 40 secs. K146Non-volatile memory. Message looping option. $30.80 Prices include GST – shipping extra. Full documentation available from website. Want cheap, really bright LEDs? We have the best value, brightest LEDs available in Australia! Check these out: Luxeon 1, 3 and 5 watt All colours available, with or without attached optics, as low as $10 each Low-cost 1 watt Like the Luxeons, but much lower cost. •Red, amber, green, blue and white: Just $6 each! Lumileds Superflux These are 7.6mm square and can be driven at up to 50mA continuously. •Red and amber: $2 each •Blue, green and cyan: $3 each Asian Superflux Same as above, but much lower cost. •Red and amber: Just 50 cents each! •Blue, green, aqua and white: $1 each. Go to www.ata.org.au or call us on (03)9419 2440. siliconchip.com.au June 2005  49 Serviceman’s Log – continued problem to begin with, we would have replaced it and charged accordingly in the first instance. However, it wasn’t anything to do with the electronic problem we had already fixed. In any event, we haven’t heard from Mr Riley for the last three months, so hopefully that’s the end of the matter. Loewe TV set I wish I could say the same about my car. Denon stereo unit We repair quite a few Denons and see a lot of UDM50 stereos with CD problems – in particular, the 3-tray stacker which can easily go out of alignment and jump a tooth, thus causing the microprocessor to shut it down. This is normally caused by rough treatment; eg, if the unit it bumped. Recently, Mr Riley brought in his UDM50, complaining that it wasn’t working and that the display was showing a “MEC ERROR”. We began by stripping the unit down on the bench and switching it on. Normally, if it is out of alignment, you can see the loading motor attempt to go in and out in a sequence, before closing down. However, in this case, nothing was happening at all and yet the tray appeared to be perfectly aligned. Next, the voltages to the mechanism were checked and found to be all over the place. The reason for this was easy to diagnose – there was no earth path running to it. The 16-way flexible cable had cracked and hard wiring an extra ground lead fixed the problem. The now working set was demonstrated to Mr Riley when he picked it 50  Silicon Chip up but when he got it home, it had exactly the same fault and so he brought it back immediately. This time, the fault was mostly ours as we had left a CD in one of the trays and when it was transported, the CD jammed in tray 1. It was a 5-minute job to release it and explain it all to Mr Riley. He accepted this gracefully and off he went. But that wasn’t the end of it. One week later, he complained again that there was a “MEC ERROR” but now only on Disc Tray 3. We (stupidly) said this might be due to a warped tray, although this was unlikely as last time it was an electrical problem and not a mechanical one. Mr Riley brought it in again and this time the tray was out of alignment. We stripped it down and realigned the slipped tooth but could find nothing wrong. The tray wasn’t warped and we suspected that Mr Riley had lost his temper with it and banged it, causing the problem. He demanded we put in a new tray as he was now convinced that it was warped but in fact it wasn’t. He was shown it working again but was somewhat disappointed that we hadn’t put in a new tray (worth $41 plus labour) for free. Of course, if the unit had had this A 1999 Loewe 84-100 (Q2100 Chassis) came in with the no picture and no sound. It was also pulsating so I checked all seven secondary rails from the power supply for shorts. I was expecting the line output transistor (Q534) on the +145V rail to be faulty but it was OK. However, the 29V rail (U29) was shorted and this supplies IC I594, the east-west amplifier. This IC is a TDA8030 (=L165), a common audio output device. It was replaced and the set burst into life but there was no east-west control. I then found that resistor R593 (1.5W) from the output to the east-west modulator circuit had been destroyed, so this too was replaced. Unfortunately, when it was switched on again, the set reverted to pulsating and IC I594 and R593 were again destroyed. I checked the whole circuit out again and “blew up” another set of parts before I woke up to the fact that the horizontal deflection yoke was short circuit. A faulty deflection yoke is often the death knell of a TV set, as they are usually only sold as part of the picture tube, which often costs more than the entire set. In this instance, though, the yoke was sold as a separate spare part but it is now no longer available. And so that was the end of the matter and the Loewe went to that great big TV graveyard in the sky. Other problems I have encountered with this chassis include ceramic capacitor C534 (2.7nF) which is across the collector-emitter of the line output transistor. L3366 (4.7mH) and R3366 (100W) also cause problems. When these parts fail,+210V is applied to the CRT socket RGB output ICs and the set briefly displays a bright white raster with retrace lines before shutting down. Why fix an old set? I am still seeing a few JNL televisions, even though the company that imported them has disappeared. But siliconchip.com.au what amazes me is that some people are quite prepared to pay a motza to get their old sets fixed, despite new ones being so cheap. The JNL5103 is a 51cm AV stereo TV that’s broadly based on a Sanyo A3 chassis and isn’t a bad little performer for such a cheap model. The one I have just had in belonged to Mrs Jones and was dead. It had been behaving erratically for quite a while, being difficult to switch on and making noises in the speakers on standby. When I opened it up, I found that most of the electrolytics (C559, C562, C563, C5332, C537) in the secondary of the switchmode power supply had swollen, indicating that the regulation had failed. Furthermore, both sound ICs had failed (N701, N711 AN5265/ CD5265CS), as well as fusible resistor R910 (1W). I replaced these parts and as in the Sanyo sets, I also replaced the preset 110V potentiometer R551. That’s because these presets tend to crack and make intermittent poor contact with the rivets to the legs. I also replaced R555 and R556 (both 47kW) and R554 (150kW), as I have had these go high in Sanyo sets. Thinking everything was sweet now, I left the set switched on for a soak test. It went perfectly all day, so I switched it off to standby for the night. The next day I was surprised to discover that it wouldn’t switch on. Looking inside, I was horrified to see that some of the new electrolytics I had just fitted had blown up and the sound ICs and resistor had failed again. (Actually, to be factual, only one IC at a time goes short circuit, protecting the other by blowing the fusible resistor). OK, I had missed the problem the previous day – the set was working fine when fully on but was failing in standby mode due to the increased voltage. This time I also replaced V551 (2SC949), D551 (a 6.2V zener) and optocoupler VD525 (PC8176). I then left it on standby, with a DVM monitoring the 110V rail. Within an hour, it suddenly started to rise sharply to over 200V. Fortunately, I was there to promptly switch the set off, before any damage occurred. Well, at last I had actually seen the fault happen but as I had already replaced nearly all the feedback circuitry, I was running out of ideas. I concentrated my efforts on the switchmode power supply and applied heat from a hairdryer, followed by freezing, to track down any sensitive components. Finally, I found that transistor V511 (2SA1015) was responding to this treatment and was very slightly leaky. This transistor is in the error detection circuit in the power supply and replacing it and leaving the set on soak test for a very, very long time confirmed my diagnosis. To protect the audio ICs from blowing up again, I fitted a 24V zener after the fusible resistor on the 19V rail. If there are any further problems, the fusible resistor should now blow before the ICs are damaged. A sharp diagnosis Mr Colcraft is an old-age pensioner who owns a Sharp CX6N5 TV set which is only a few years old. The set was dead and he wanted a house call. I agreed to go but I have to admit that I was rather anxious about how to approach a set I had never seen before without a circuit diagram. Fortunately, I soon got the hang of the thing. Power was arriving into the Custom-made Lithium Ion, NiCd and NiMH battery packs Smart Chargers www.batterybook.com (08) 9240 5000 High-capacity 280mAh rechargeable 9V 2400mAh NiMH AA cells siliconchip.com.au High-quality single cell chargers with independent channels. Charge any combination of NiCd & NiMH AA and AAA cells High-capacity 9Ah rechargeable D June 2005  51 Serviceman’s Log – continued switchmode power supply but nothing was coming out of the secondaries. There were no measurable short circuits on the supply rails and the line output transistor was OK. The standby LED wasn’t on but there was 330V on the main electrolytic filter capacitor. Nothing was pulsating, so it looked to me that the start-up circuitry was faulty. I then noticed a small 1.8MW resistor (R5701) from the bridge rectifier to the +330V rail which looked suspicious. I measured it to find it gone very high in value. Replacing it with a high-voltage 0.5W resistor fixed the fault, much to my relief – I really didn’t want to take the set back to the workshop. Blaupunkt Mr Forsythe was persuaded to bring his 1997 66cm Blaupunkt IS70-33 VT PIP(FM310.32 = Grundig CUC5360 chassis) into the workshop, as I couldn’t see myself solving what was an extremely intermittent sound problem in his home. It was just as well, as the fault didn’t show until after three days of continuous running. When it did, it could be persuaded to return if you turned the volume up but not down. I started by looking for dry joints but the only significant one I could find was on one of the deflection plug 52  Silicon Chip pins. Heating and freezing the audio output IC made no difference and all the supply rails checked out OK. The fault seemed to be on the IF module (29504-102.70c) which carries the TDA6610 (IC2250 stereo decoder IC. I unsoldered the IC and fitted an IC socket and the set then started to work and wouldn’t fault again. The remote also didn’t work and after I eventually managed to get the case apart, I found that this was due to a broken ceramic crystal leg. When I quoted Mr Forsythe, I was surprised when he decided not to go ahead with it, especially as the set cost about $2000 eight years ago (this model has picture in picture and teletext). Instead he decided to use a powered loudspeaker set (as used with PCs) connected to his VCR for sound. I guess it takes all sorts. Older sets not wanted I still repair older sets when their owners beg me but I don’t encourage it. A decade is good value for the amount of entertainment people get out of their tellys – much cheaper than reading books. I often hear “I have had this set for 30 years and it is has NEVER broken down”. My response to that is “PLEASE show it to me”, as I have never seen ONE yet. The fact is, peoples’ memories are just not that good. I remember 20 years ago when the National Manager of AWA/Thorn addressed a technical meeting of TETIA (Television and Electrical Technicians Institute of Australia) in Sydney and he started by saying “Gentlemen, you are all out of a job. These new Mitsubishi TVs just won’t break down”. Well, compared to their previous TCE-designed 3K5 (3504) and later 4KA chassis, that might have seemed a sure bet but even so, Mitsubishi sets have given me steady work (as have all other brands, bless them) and helped pay the bills for the last 20 years. And they were excellent sets, well designed and built. The set I was asked to fix was a Philips 28GR6781/75R using a G111.3 chassis of the early 1990s. It was dead but pulsating and after a while showed a dull intermittent blob/line in the centre of the screen. To all intents and purposes it looked to me like dry joints or the flyback transformer and/or possibly a vertical timebase fault dragging the horizontal output down. When I removed the chassis and after measuring and making sure the +320V main reservoir capacitor was discharged, I resoldered a number of rather dry joints to the flyback transformer, the deflection yoke and the East-West transformer. I could “smell the fish” from the leaking 1500mF 35V electrolytic capacitors, so I replaced them and checked for corrosion damage but the fault persisted. By shorting out the base-emitter junction of the horizontal output transistor and hanging a 150W globe on the collector, I could see that the +140V rail was steady. I disconnected the SCR crowbar and tried a new EEPROM, then changed the flyback transformer – all to no avail. I retraced my steps and tried a 60W globe instead of the impromptu 150W globe I had used before. This time, the globe was pulsating and the voltage on the analog meter showed it was bit high. I could get it to stop pulsating by turning down the 140V B+ control but the voltage was still a touch too high. Finally, I located a small 75kW resistor feeding back from the 140V rail to the control circuitry that had gone high resistance. Replacing this resistor and then resetting the B+ control back to where it was fixed all of the SC symptoms. siliconchip.com.au [ June 2005 ] HIGH RESOLUTION Digital TV Tuner Price breakthrough! At last you can enjoy the benefit of fantastic HIGH RESOLUTION Digital TV at the price of standard resolution units. It is fitted with a standard PAL input/output socket, so you can plug your antenna straight in. Also included is a comprehensive remote control and some A/V leads. There are provisions for S-Video, RGB (YCbCr / YPbPr), and composite video, but no Scart output. Console measures 305(W) x 200(D) x 55(H)mm. See in store for more details. 12V Can Cooler Cold drinks on long trips! This great device plugs into your car’s cigarette lighter socket and holds a standard size 375mL can. It is a great way to keep your drinks cold in summer, Cat. GH-1370 $ .95 and on long trips. 29 Roll-Up Electronic Piano For the travelling maestro! Just roll it out and you are ready to play. It has over 100 instrumental sounds, and its built-in amplifier means you can entertain a small crowd. It has 49 keys covering 4 octaves and even an inbuilt recorder. •710(W) x 174(D) x 5(H)mm. Cat. XC-4827 $ .00 299 Note: No demo facilities available in our stores. Not at this price. 99 LCD Virtual Goggles Take the cinema screen with you! Enjoy private viewing of your TV/DVD/VCR or games console with these lightweight goggles. So portable they can be used in a car to enjoy DVD player entertainment, or connect it to a video games console such as PLAYSTATION, XBOX, etc. Supplied with cables and Cat. QM-3790 power adaptor. 800 x 225 (180,000) $ .00 pixel resolution. 399 Wireless Key Finder Never lose keys again! Simply attach your keys to one of the receivers. Then when you press the corresponding button, it will beep so you can find it. There are four receivers supplied, each with their own button on Cat. XC-0352 the keyfob style transmitter. $ .95 49 Multifunction 4 in 1 Pen Stylish and functional! This stylish looking pen looks like an ordinary writing pen but it also includes a laser pointer, torch and PDA stylus. Includes presentation case. Cat. ST-3101 $ .95 Coax Seal Tape KIT OF THE MONTH 24 LED Upgrade Kit for Maglites Better efficiency! Upgrade the bulb in your AA Maglite™ to this unit that has 3 LEDs. Because LEDs are so efficient, you get four times longer battery life, and LEDs don’t blow! This is the Cat. ST-3400 single best upgrade to a $ .75 torch you can make! 14 Monitor your car’s air:fuel ratio in real time. Ref: Silicon Chip Sept/Oct 2000. This brilliant dash mounting unit features a three digit LED display, as well as a bargraph for readings at a glance. It indicates air:fuel in real time of 11.8 - 20.6 for petrol, and 12.7-21.5 for propane/LPG. It has loads of great features, just check out our website. Kit includes PCBs, laser cut panels, Cat. KC-5300 pre-programmed PIC, and all $ .95 electronic components. 62 2.4GHz Wireless Audio Video Sender Watch cable TV all over the house! Send a signal from a DVD player, set-top box etc., to another room, without the use of any cables! You can use as many receivers as you like, without degrading signal quality. Each unit comes supplied with stereo audio and video transmitter and receiver, mains plugpacks & RCA cables. Transmission range is up to 100m, but depends on the type of construction materials used. Was $99 Cat. AR-1832 SAVE $ .95 $29.05 69 Extra receiver to suit Cat. AR-1833 .95 Cat. AR-1833 Was $69 $ 49 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 SAVE $19.05 2.4 GHz Wireless A/V Sender with Remote Control Extender With the addition of an IR remote control repeater you can change the channel of the source device etc from the other room. Cat. AR-1830 $ .95 Was $139 Extra receiver to suit Cat. AR-1831 Cat. AR-1831 $ .95 Was $89 INTERNET> www.jaycar.com.au This clock is hypnotic! Ref: SC June 2005. It consists of a PIC driven clock circuit which drives a 12 or 24hr 8segment display. Also, around the perimeter are 3mm LEDs, and 5mm LEDs every 5 seconds. The clock produces a dazzling display as it counts the EXCLUSIVE seconds, which is so good it can’t TO JAYCAR be properly explained here. Log onto our website and follow the prompts to see it in action. Kit supplied with double sided silk-screened PCB, and all board components, as Cat. KC-5404 $ .00 well as the special clock housing. 129 CHECK OUT THE GREAT PRICE! Digital Fuel Mixture Display Kit Cat. GH-1610 $ .95 "Clock Watchers" LED Clock Kit 89 SAVE $49.05 69 SAVE $19.05 No more water ingress! Seal your outdoor coaxial connections to prevent moisture entering the connectors which hampers signal quality and causes corrosion. Simply wrap it around the connector and cable, and it will turn into a removable water Cat. NM-2828 resistant seal that lasts for years. $ .95 •12mm wide •1.5m length. 9 As used by NASA and the US military Non-Contact Voltage Tester with Adjustable Sensitivity It’s time to upgrade! We have all used contact and non-contact testers before, but here is something new. This one has an adjustable sensitivity so you Cat. QP-2276 can start using the sensor from up to 1m $ .95 away! Also features a small LED torch. 19 Shed / Garage / Boat Alarm Very affordable! The garage or shed can often be neglected when it comes to security, but often there is valuable machinery and tools inside. This unit consists of a reed switch for the main door, and a PIR for general protection. Keyfob arm / disarm. Includes mains Cat. LA-5400 plugpack, 10m cable, and a battery $ .95 backup option. 49 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 12V <at> 12A 24V <at> 6A Cat. MB-3610 Cat. MB-3614 Cat. MB-3612 $ .95 $ .95 $ .95 79 99 99 1 RFID Access Control System No contact required! Control entry to a doorway, or an entire building. The unit can be used in a network of locks administered by a central location, or just to control access through a front door. It is 12V powered, so you can use it in remote locations, and the reader unit is splash proof. 5 RFID cards included. Cat. LA-5120 •N.O. and $ .00 N.C. relay contacts. 199 3 Zone Wireless Home Alarm Kit Ideal for tenants! The system is supplied with a control panel equipped with keypad, and a built-in siren. It also comes with a wireless PIR, reed switch, and panic Cat. LA-5125 $ .00 button which operate within a 50m range. There are also provisions for hard-wired expansion if desired. See our catalogue page 326 for details. 199 GREAT NEW 2.4GHZ WIRELESS SURVEILLANCE EQUIPMENT 2.4GHz 4 Channel Wireless Receiver with Remote Control 2.4GHz Wireless Colour CCD Pinhole Camera High quality picture! A Sharp 1/4" CCD sensor provides clear 420TV line resolution picture, and can transmit it up to 100m to the receiver (use QC-3588). A mains plugpack is included, and there are two channels available: Both Types $ EA Channel 1 Cat. QC-3560 Channel 2 Cat. QC-3561 229 2.4GHz Weather Resistant Wireless Colour CCD Camera with IR LEDs Night vision! As well as 420TV line resolution, this camera has 27 integrated infrared LEDs to see in the dark. It is weatherproof, great for mounting under eaves, and a mains plugpack is included. QC-3588 receiver required. Two channels available: Both Types Channel 3 Cat. QC-3564 $ EA Channel 4 Cat. QC-3565 269 2.4GHz Wireless Colour CCD Rechargeable Camera with Audio The ultimate in portability! This camera features an internal Lithium-Ion rechargeable battery that can operate the camera for up to 5hrs per charge. Channel selectable to use with Cat. QC-3595 .95 QC-3588 receiver, see $ website for details. Fantastic price! Don’t pay thousands, this unit has 420TV line resolution, 350° panning angle, and 90° tilt range. It has 3x optical zoom with 4.2 – 12.7mm focal length. It has many features normally Cat. QC-3500 $ .00 reserved for high priced units. 799 5" B&W Surveillance System Quick and simple! Consisting of a 5" B&W surveillance monitor, two cameras, and two dummy cameras, you can keep an eye on your premises. The real cameras simply plug in with their 10m lead, and the dummy cameras look identical. Great for small shops. Cat. QC-3446 $ .00 149 Cat. QC-3593 $ .95 129 4 Channel B&W Quad Video Processor Great price! At the heart of many surveillance systems is a 2.4GHz 4 Channel Wireless USB Receiver multi-channel processor filtering all the cameras into one channel. This B&W quad unit is far cheaper than Surveillance on your computer! many other available models, with many features. This tiny four channel receiver takes the pain See website for details. out of surveillance. Just plug it into your Cat. QC-3375 PCs USB port and you’re set. You can view $ .00 cameras on the PC, with a composite option for a TV or monitor too. There is a host of 4 Channel Colour Quad Video Processor on-board functions Low cost! such as email alert on Similar to the unit shown above, this colour model is motion detection, and a whole lot more. Cat. QC-3597 low cost with great features. Advanced features such See page 313 of our 2005 catalogue for $ .95 as video freeze, zoom, picture in picture, and motion more info. detection are all there, usually reserved for high priced 2.4GHz Wireless Colour LCD Receiver units. Roam while monitoring! Cat. QC-3377 Now you can take your $ .00 surveillance monitor with you to watch the kids, or keep a lookout for potential thieves. It has a 65cm LCD Two Channel 6" B&W and a speaker for audio. Cat. QC-3596 Surveillance Monitor See 2005 catalogue page $ .00 Small and compact! 312 for compatible cameras. Ideal for small surveillance setups such as shop-front Colour CMOS Pinhole Camera monitoring. It has two video inputs with Audio with a manual switch for input Tiny size! selection. It weighs just 1.5kg, and Cat. QM-3409 Measuring just 20mm2 x 19mm, is powered by an external mains $ .95 this camera can be placed just plugpack. about anywhere you can get the cable to. It can be powered from Downlight Style Colour CCD Camera 6 - 12VDC, and operates in low-light Cat. QC-3491 Unique mounting! $ .95 conditions down to 2.0 Lux. Using a 1/3" Sharp CCD sensor to provide high quality 480TV Check out our June CLEARANCE line resolution images, the Halogen downlight style mount flyer in June Silicon Chip fits in with your décor, as well Magazine and in-store NOW! as allowing 0 - 90° Cat. QC-3503 pivoting. See $ .95 website for details. 4 Input IP Sensor Modules Security over the Internet! 2 Channel Video Web Server This 4 input sensor can be given an IP address with Email Alert Remotely monitor your system! so you can IP (Internet Protocol) surveillance has revolutionised monitor the the way we monitor and record in many surveillance state of the situations. This web server can be connected to an inputs from existing setup, and transmits up to 12fps at 640 x 480 anywhere in the world resolution. It has two video inputs and four with an internet browser. It can be used for PIRs, alarm inputs to email you alarm sensors, lights, and more. Password when one is triggered. protection, polarity protection, and Cat. LA-9040 Cat. QC-3394 more included. $ .00 $ .00 See Cat page 327 for full details. 149 249 299 299 169 USB Pan / Tilt PC Camera with Remote Access This is one of the most SAVE useful PC based cameras $100 we have seen! It has full functionality as a pan/tilt camera, with motion controlled via the serial port! You can log onto a preset IP address, and actually take control of the pan/tilt functions. Software and drivers are supplied on CD-ROM, and it is compatible with Windows 98,SE,ME,2000, and XP. •640 x 480 pixels resolution. •Colour CMOS sensor. Cat. QC-3395 •111(L) x 97(W) x 86(H)mm approx. $ .00 Was $399 299 Long Range 120m Twin Beam Driveway Monitor 240m range indoors! Now you can reliably monitor an entryway of up to 240m indoors, or 120m outdoors. Installation is easy thanks to built-in laser guides, and dual beams help eliminate false Cat. LA-5199 alarms from birds or debris $ .00 etc. See website for details. 299 2 Audio and video! Receiving up to four 2.4GHz cameras (any of the cameras shown left), you can switch between cameras manually, or set it to automatic. Composite video output allows display or recording on any device. A mains plugpack and RCA cables are also supplied. Pan / Tilt / Zoom Dome Camera 89 49 249 129 399 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au 1 Farad 20V Capacitor with Voltage Display Carbon Fibre Subwoofers New range! Featuring high quality Carbon Fibre cones and dual voice coils, these new subwoofers offer great performance and durability. •See website for full details. Car audio enthusiasts please note! This massive capacitor will help stabilise the voltage levels in a high power stereo installation. A voltage display keeps you informed of voltage Cat. RU-6750 $ .95 levels, and mounting hardware is included. 128MB MP3 Player with LCD Screen 79 6.5" Kevlar Split Speakers Fantastic sound! A new design of our previous Kevlar split speakers, they sound great. They have a great sounding 25mm soft dome tweeter, as well as separate crossovers for optimum performance. •250WRMS power handling. •Dual 4-ohm voice coils. CS-2278 •87.1dB sensitivity. $ .95 •2 x 80WRMS <at> 4 ohms. •2 x 100WRMS <at> 2 ohms. AA-0420 •1 x 200WRMS <at> 4 ohms. $169.95 12" Subwoofer 4 x 50WRMS 179 Very portable! Take your music with you wherever you go, without a bulky player. This MP3 player stores up to 2hrs of music on its internal memory, and you can also use it to transfer data between computers. It has a screen to tell you what track is playing, as well as the track progress. •83(L) x 32(W) x 21(H)mm. Cat. GE-4001 SAVE Was $149 $ .00 $70 •300WRMS power handling. •Dual 4-ohm voice coils. CS-2279 $ •88.2dB sensitivity. 219.00 •4 x 50WRMS <at> 4 ohms. •4 x 80WRMS <at> 2 ohms. •2 x 160WRMS <at> 4 ohms. Kevlar Cone Coaxial Speakers Fantastic quality! This new range of coaxial speakers offer high performance and great looks. They retain the large super tweeter that made last year’s range great, but the new Kevlar cones take them into a realm of their own. Check out our catalogue page 229 for full details. 4" Kevlar 2 Way Cat. •40WRMS power. CS-2320 •86.5dB sensitivity. $99.95 Cat. CS-2329 $ .95 pr 149 Coaxial Speakers Cat. •50WRMS power. CS-2322 •89.5dB sensitivity. $109.95 •75WRMS power. •91.3dB sensitivity. 24.95 •30WRMS power handling. •88dB sensitivity. CS-2332 29 $ 6" 2 Way .95 •35WRMS power handling. •89dB sensitivity. CS-2334 6" x 9" 5 Way •45WRMS power handling. •90dB sensitivity. CS-2336 49.95 $ Speaker / Source Control Wall Plates Control the music around your home! With these inexpensive units, you can control volume, select speakers, and even sources! It allows you to wire your home with sound, while maintaining flexibility. See website for full details. Source and Speaker Switch Select between two sources Cat. AC-1677 $ .95 and distribute to one or both pairs of speakers. 19 2 Way Speaker Switch Switch between two speaker Cat. AC-1679 $ .95 pairs quickly and easily. 19 70W 12 Step Stereo Loudspeaker Attenuator Attenuates by up to 46dB on an 8-ohm system for tailored listening Cat. AC-1685 levels. $ .95 39 54 A great mounting solution! If space is limited, or you simply don’t want free standing speakers, then these are a great option for you. 8 ohm impedance allows them to be used in an array of applications. Supplied with attractive white baffle covers. 2 Way Cat. CS-2440 $99.00 3 Way Cat. CS-2442 $149.00 INTERNET> www.jaycar.com.au 4 x 100WRMS •4 x 130WRMS <at> 4 ohms. •4 x 190WRMS <at> 2 ohms. •2 x 380WRMS <at> 4 ohms. AA-0426 299.95 $ Secure Clip-On Earphones Enjoy the surround sound experience. The centre speaker contains a screened 4" mid/woofer, and 2" tweeter with a 6 ohm impedance. The two rear speakers contain a 4" full range with Cat. CS-2465 SAVE $ .95 a 4 ohm impedance. $45 2004 Cat Price $99.95 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 .95 3 Piece Surround Sound Add-On In Wall Speakers 249.95 399.95 199 39.95 $ AA-0424 $ AA-0428 Great for the car or home! Here is a great way to enjoy movies, music, and picture slide shows on your TV or PC monitor. It accepts many common memory cards so all you need to do is load the files on the card, pop it in and you're away! The IR remote control operates all functions, including great features such as image zoom, image rotate, slide shows, and various other great functions. It supports MPEG4 encoded files in MPG, DAT, and AVI format, and Cat. XC-4865 $ .00 can also play music and image files. See our website for full details. Measures 125(W) x 22(H) x 83(D)mm. $ 5" 2 Way •2 x 150WRMS <at> 4 ohms. •2 x 255WRMS <at> 2 ohms. •1 x 500WRMS <at> 4 ohms. $ MPEG4 Media Player •25WRMS power handling. •88dB sensitivity. CS-2330 2 x 150WRMS Cat. CS-2324 $ 199.95 $ •1 x 400WRMS <at> 4 ohms. •1 x 700WRMS <at> 2 ohms. •1 x 820WRMS <at> 1 ohm. 5" Kevlar 2 Way 6.5" Kevlar 2 Way AA-0422 800WRMS Class D 119 This new range of budget coaxial car speakers offer great sound and value for money. Cat. They have low-profile magnets for versatile mounting, 6" x 9" 2 Way •80WRMS power. CS-2328 $ .95 and spoke grill covers for show. •93.5dB sensitivity. 139 4" 2 Way Great value! Even with very affordable prices, these amps don’t offer any less than major brand models available on the market. There is an amp to suit every application, just take a look. See our website for all the great features. 2 x 80WRMS 10" Subwoofer 99 NEW CAR AMPLIFIER RANGE Won’t fall out when you’re jogging! They are comfortable to wear, sound great and will give you hi-fi performance from the Neodymium Cat. AA-2023 speakers. 3.5mm $ .95 stereo plug. 12 7” Widescreen TFT LCD Monitors for Cars See our website for full features & specs Standard Mount 7" Monitor Great versatility! It offers wide viewing angles, image reverse, and more! Was Cat. QM-3752 $399 $ .00 299 SAVE $100 Roof Mount 7" Monitor 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 SAVE $ .00 $90 329 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 $80 369 3 Mini LED Torches Great on a keyring! Light the way with these tiny LED torches. They are lightweight and will fit on your keyring. •45(D) x 10(W) x 10(H)mm 3 colours available. Blue Cat ST-3380 White Cat ST-3382 All Types EA 3 $ Red Cat ST-3384 .95 Proximity Security Beeper Never lose valuables again! The Proximeter transmitter attaches to your valuables, and you keep the receiver in your pocket. If you walk away from the transmitter, it will beep, reminding you to grab your possessions. Cat. GG-2375 29.95 $ Very versatile! Not only does this dynamo powered device have an AM/FM radio and incandescent lamp, there is a host of other functions. There is a 3, 6, 9, and 12VDC output socket to provide emergency power, and a plugpack can also be used to charge the internal battery. It also has two-way charging; wind the Cat. ST-3370 $ .95 handle to charge your car battery, or let you car battery charge it! 59 Farting Salt n Pepper Shakers A great gag for all occasions. They make a fart sound when tipped upside down. Great for parties! Cat. GH-1080 Cat. XC-0248 24.95 $ Time flies when you're exercising! This pedometer has a built-in MP3 player which stores up to two hours of music. More than enough for most fitness programs! Pedometer functions include calorie counting, distance monitor, as well as a clock. Supplied with USB cables and earphones. •68(L) x 39(W) x 22.5( H)mm Cat. GE-4012 119.95 $ Pedometer with FM Radio and Calorie Counter Keep track of your calories! You can input the food you have eaten, and it will count down how far to go until you have walked it off. Many other functions, see our website. Cat. XC-0267 19.95 $ Multi-Currency Coin Bank Count your savings! The counter can be set to one of 37 different countries, including the European Union. It then displays the total amount of money on the LCD screen. Measures 125(H) x 95(Dia.)mm. 14.95 Hand Held Farting Keyring Every practical joker should have one! Cat. GH-1082 $ .95 Makes a great farting sound when the button is pressed. 9 Remote Controlled Secret Farter Colour Master Colour Changing LED Lighting Kits Fun and funky! Mount them in laminate or wooden floors, walls, or even ceilings for great mood lighting. They can be changed from red, blue, or green, auto changing or static. Supplied with controller and mains plugpack. Lights measure 80(Dia) x 6(H)*mm. *6mm protruding from mounting Includes 4 x round LED fittings, 12.5m of cable, and controller. Eight Light Pack Cat. GH-1088 Includes 8 x round LED fitting, 22.5m of cable, and controller. 19 .95 $50 •4x digital zoom •Internal microphone and lots more! Cat. QC-3230 199.00 $ 34 Remote Controlled Massage Seat Cover Pad with Built in Heater 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. Supplied with car Cat. GH-1753 and mains $ .95 adaptors. Cat. ST-3882 139.95 $ 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 Cat. GT-3420 wheels for full use of the props. $ .95 •Approx 180mm long. Remote Controlled Battle Submarines - Pair SAVE $5 24.95 Radio Controlled Submarines SAVE $5 29 49 $ Great underwater fun! They have full manoeuvrability with forward, reverse, left and right, and a power dive function. Two types available: 27MHz Yellow GT-3044 40MHz Blue GT-3045 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 79.95 Cat. GT-3225 Were $29.95 Set a romantic atmosphere! These rechargeable wireless lights slowly change from one colour to the next, and have a soft glow for romantic or mystical effects. They are charged on their base, and run for up to 6hrs. Cat. GH-1047 1 Piece Set Cat. GH-1047 $ .95 Includes 1 OGGZ, charging base, and mains adaptor. Cat. GH-1048 3 Piece Set Cat. GH-1048 $ .95 Includes 3 OGGZ, charging base, and mains adaptor. $ Swims underwater! It has full manoeuverability with forward, reverse, left and right and a power dive function. Was $29.95 OGGZ - Colour Morphing Mood Lights Cat. ST-3880 Radio Controlled Clown Fish Mini Digital Video Camera Fantastic price! This easy to use camera fits A digital video camera for in the palm of your hand! under $200! The recorded video can be transferred to a computer for editing, or simply viewed directly on any TV with AV inputs. Supplied with camera bag, cables and software. •3.1 mega pixel software resolution for stills. •1.5" colour LCD screen. •5 layer glass lens. •32MB internal memory SAVE Was $249 •SD/MMC expansion slot 49.95 $ Bookmark Electronic Dictionary Two packs available: Four Light Pack The new millennium’s whoopee cushion! Activated by a remote control, it has three realistic fart sounds. Cat. GT-3495 49 $ 19.95 Hours of fun! Test your skill by manoeuvering the ball over the plus score numbers, and not over the minus score numbers. Three different ways to play. 69 Cat. GH-1315 $ 4 Great in the workshop! This alarm clock can bolt under an overhead cabinet, or simply sit on a desk. It includes an AM/FM radio so you can wake up to the morning news or a simple buzzer. Mains powered. Pedometer with 128MB MP3 Player 5 in 1 Dynamo Power Bank with Radio and Lamp $ Time Ball - Electronic Game of Skill Under Cabinet Alarm Clock Both Types 24.95 $ Underwater battle fun! A new twist to our everpopular radio controlled submarines. They incorporate a combat mode to seek and destroy your opponent by tailing and shooting them down! Once shot, the opposing submarine is disabled for 20 seconds. They are switchable to normal mode if you are not in the mood for a bloodbath! Cat. GT-3043 49.95pr $ FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au Deluxe Map Distance Calculator New model! This new Map Distance Calculator can operate in metric or imperial units, as well as nautical miles for marine or aviation applications. Roll it forward to add distance, or backward to subtract. It has a backlit display and Cat. XC-0377 small torch for night use. $ .95 Measures 155(W) x 35(H) x 23(D)mm. 39 Digital Map Distance Calculator 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 Cat. XC-0375 and displays in kilometres or miles. $ .95 19 Mini Electric Toy Safe More compact! This mini version of our regular toy safes has keypad entry and great sound effects. It measures 132(L) x 105(H) x 122(D)mm, and A great way has a coin slot to save pocket in the top. money! Cat. GH-1312 19.95 $ Buy 2 for $89.95 and get 2 FREE sets (8pcs) of batteries (SB-2444). Total saving $45.60! Both Types (ea) 19.95 $ 1.5W High Powered UHF CB Band Transceiver Massive range! Up to 8km working range with a hi/lo setting to conserve power. Cat. DC-1040 Was SAVE $ .00 $119 $20 40 Channel UHF CB Transceiver Wrist Watch Full function in a wrist watch! They are extremely portable, and use internal rechargeable batteries. Up to 2km range. Was $169 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. Cat. GH-1095 49.95 $ 139.00pr $ The Amazing Flygun! Cat. GT-3440 59.95 $ Keep the kids entertained! The Amazing Flygun is a safe, fun, and effective method of killing flies and mosquitoes. Launch the spring powered swatter at your target! It is safe, fun and really does work! Cat. YS-5545 KILLS $ .95 COCKROACHES TOO! 7 Intelligent Automatic Rubbish Bin 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. Hands full? No worries! Just wave your hand, foot, or whatever you can, in front of the intelligent rubbish bin and the lid will open automatically! It will also close back up again, so you never need to touch it. Cat. GG-2315 $ .95 23L capacity. 9 39 “Norbert” Robotic Vacuum Cleaner 44.95 $ Sit back and relax while your robot cleans the house! It automatically moves around obstacles, and an intelligent optical sensor assists in avoiding walls & obstructions. Works best to supplement your Cat. GH-1395 manual cleaner, $ .00 not replace it. Spare Dust Filters Pk 2 Cat. GH-1396 $29.95 Mop Papers Pk 100 Cat. GH-1397 $24.95 249 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. 12V Camping Shower A touch of luxury! Wash away the cares of the day no matter how far from civilisation you are! The camping shower allows you to take a shower wherever you are. Cat. YS-2800 Powered by your $ .95 vehicle’s 12V battery. 19 FOR INFORMATION AND ORDERING INTERNET> www.jaycar.com.au SAVE $30 Cat. DC-1070 Slimline 3 LED Book Light Cat. GH-1093 TELEPHONE> 1800 022 888 59 Air Powered Jet Hawk Glider 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! 99.95 Cut out CB traffic noise! It remains silent until ‘called’ from another CTCSS equipped transceiver. Up to 5km range Was $59.95 Great range, great features! Since the outstanding success of our popular DC-1010 transceiver, it only seemed logical to SAVE refine the design, $30 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 Buy a transceiver and a charging DC-1025 with cradle. Was $89.95 an extra transceiver Cat. DC-1025 (DC-1028) for just $ .95 $99.90! Save $60! 99 Shocking Lie Detector $ *Rechargeable batteries sold separately 40 Channel UHF Transceiver with CTCSS 49.95 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! Cat. GH-1099 or 2 for $69.90 39.00 $ $ Electric Shock Reaction Game Shocking Tank Battle Set Cat. DC-1010 Rechargeable 40 Channel UHF Transceiver Cat. DC-1030 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. 40 Channel UHF CB Band Transceiver Cheap short distance communication! They operate up to 5km in an open field, or 1km in the city. Lots of accessories available, see our website for details. 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. Cat. QM-7294 69.95 $ Alcohol Breath Tester with Readout Measure your BAC! Displays blood alcohol concentration between 0.00% & 0.05%. It provides a good result, but should not be relied upon to produce precise results. Cat. QM-7292 $ .95 Was $59.95 49 SAVE $10 5 1000V 7 Piece Screwdriver Set Vacuum Bench Vice GS and VDE tested and approved. Soft rubber grip handles, with insulation right to the tip. CHECK THIS GREAT PRICE! Cat. TD-2022 $ .95 19 Multifunction Screwdriver with Wire Cutter / Stripper 47 A must have for every toolbox! It has seven interchangeable bits, can also cut cable up to 12AWG, and strip cable between 10 and 20AWG. Cat. TH-1822 $ .95 HSS Step Drill Bits - 1mm steps Drill multiple size holes with the one bit! Suitable for plastics and un-hardened metals (such as aluminium or copper sheeting etc) up to 4mm thick! Made from high speed steel (HSS). Two sizes available: 4-12mm Cat. TD-2436 12-20mm Cat. TD-2438 Cat. TD-2438 Cat. TD-2436 $ .95 $ .95 29 Battery / Charger / Alternator Tester 9 Universal Ni-Cd / Ni-MH Battery Charger with Discharge 29 Cat. MB-3500 $ .95 39 24 SAVE $20 11 Super Torque Driver Ratchet Comfortable driving! It accepts standard driver bits, adjustable and lockable head angle, with a rubber grip handle. Was $13.95 SAVE $4 9 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 Check out our flyer in June Silicon Chip Magazine and in-store NOW! 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. Cat. MS-6102 $29.95ea. SAVE $15ea 20A Solar Charging Controller with LCD 169 12 SAVE Made in Japan! $5 The highest build quality for years of service. Measures 330mm long. Cat. TH-1856 Was $24.95 $ .95 19 7 Pc Hex Nut Driver Set Excellent quality. Each driver contains a deep socket and duplex colour non-slip SAVE rubber handle. $5 3 - 6mm sizes in Cat. TD-2007 0.5mm steps. $ .95 Was $29.95 24 A great selection of tools. Contains a crimp tool with 5 interchangeable dies, cable cutter, coax stripper, screwdriver, all in a handy case. Cat. TH-1878 SAVE $ .00 Was $169 $30 139 Rotary Coax Cable Stripper Cat. MS-6100 $ .95 39 SAVE The easiest way to strip coax! $5 It will strip the outside jacket and inner conductor in one operation. Suitable for RG58/59/62/6 and 3C2V 75 ohm Cat. TH-1820 cable. A quality stripper. $ .00 Was $22 17 Sealed Lead Acid Batteries High quality batteries! Our range of SLA batteries represent excellent value for money. They feature leak proof construction, long service life, high discharge capability, deep discharge recovery, and more. Don’t use low quality SLA batteries to save a dollar or two, you will just end up replacing them even sooner. Voltage Wind Powered Generator Experimenters Kit A great learning tool! This small scale project enables you to build a real working wind generator, and then use it for experimenting. It can supply up to 10VDC <at> 1A (depending on wind speed), and features an onboard 330uF capacitor so you can store the energy for later use. Kit includes all parts to make the generator, fan assembly, and pedestal. Stands 250mm high. Desolder Tool Coax Crimping Tool Kit Cat. TD-2033 $ .95 Extra mains switches 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, auto dusk-till-dawn Cat. MP-3129 on/off, overload protection & a whole lot $ .95 more. See our website for full details. 6 Top quality! This unit features a high torque motor, to drive screws harder and faster than those cheap units. Beware of inferior lower priced units - they do not have Cat. TD-2495 SAVE the same power as this $ .95 $8 unit. Was $19.95 Remote Controlled Mains Switch 1 Amp SLA Battery Chargers Fully automatic! They charge your batteries without fuss, switching to trickle charge when they reach capacity. Virtually any capacity can be charged, but the higher the capacity, the longer the charge. Was $39.95 Both Types $ .95ea Two types available: 6V Cat. MB-3525 12V Cat. MB-3526 $10 JUNE CLEARANCE Automatic 6/12V 1.8 Amp SLA Battery Charger Versatile! This charger will charge 6 and 12V SLA batteries at 1.8 amps. It includes short circuit and reverse polarity protection, as well as over Cat. MB-3523 current protection. $ .95 Was $49.95 Deluxe Battery Bulb and Fuse Tester Simple but effective! It uses three LEDs to indicate battery voltage, and another three to indicate overvoltage, max voltage, and charging status. It includes 600mm leads and a Cat. QP-2258 magnetic base to secure it $ .95 while testing. Great price! This charger automatically discharges, then fast charges the cells. Suitable for AAA, AA, C, and D cells. Automatic trickle charge, mains powered. SAVE Was $49.95 $10 Super strong suction! SAVE $3 Simple spring plunger action for desoldering. 195mm including tip. Cat. TH-1862 $ .75 Was $15.75 Quality Rechargeable Cordless Screwdriver 19 19 Metal Desolder Tool Die-cast aluminium construction! Great if you only occasionally need a vice on your workbench. It attaches and detaches without leaving a mark. Was Cat. TH-1766 SAVE $ .95 $57.95 6 Volt 6 Volt 12 Volt 12 Volt 12 Volt 12 Volt 12 Volt Capacity 4.2Ah 12Ah 1.3Ah 2.2Ah 4.2Ah 7.2Ah 18Ah Cat. No. SB-2496 SB-2497 SB-2480 SB-2482 SB-2484 SB-2486 SB-2490 Price $12.95 $29.95 $19.95 $24.95 $35.00 $36.50 $44.95 30 Minute Super Fast AA/AAA Battery Charger Cat. KJ-6696 $ .95 49 Need to charge fast? How about half an hour! Batteries It charges 2 x AAA or not 4 x AA, Ni-MH or Ni-Cd included batteries. Automatic 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 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au NEW HARDCORE ELECTRONICS! This section is dedicated to what’s new for the Hardcore Enthusiast. IC Pin Straightening Tool Encapsulated Toroidals HK-828 45 Second Voice Recorder IC No more fumbling! Straightening the pins on an integrated circuit can be clumsy and time consuming. This device takes away the hassle, and gets your ICs ready for work again. Cat. TH-1814 $ .95 •Low magnetic stray field emissions. •Low standby current. •Low profile. •Magnetic shielded. •Fully encapsulated. •See website for details. 3.2VA 12V MT-2030 3.2VA 18V MT-2032 7.0VA 12V MT-2036 7.0VA 18V MT-2038 3.2VA 7.0VA 7.0VA 24V MT-2040 $ .95 $ .95 ea ea Great for projects! The HK-828 voice recorder IC is a great low-cost record/playback device for use in many projects. There are loads of great applications and data sheets are on our website. This IC is used in a voice recorder project, described in Silicon Chip Magazine, May 2005. Cat. ZZ-8200 $ .95 9 Solder Sucker and Blower Bulb 19 Quick and simple! Cheap, compact, and very effective, you can buy a few so you always have one handy. Measures approximately 50(D) x 110(L)mm. Cat. TH-1850 $ .95 Heavy Duty Chassis Mount Relays 20A Used in motors, transformers, heaters etc. •12V, 160 ohm coil. •20A <at> 220VAC Cat. SY-4042 / 30VDC. $ .95 5 3 30A Used in heavy duty applications 10mW Green Laser Module Extremely bright! This laser module consists of a 10mW laser diode, lens, and driver PCB. Simply connect a 3VDC supply, & you have a great high Cat. ST-3117 $ .95 power laser. •Datasheet included. •Measures 65(L) x 11(dia)mm. 149 INOX – MX3 Lubricant / Corrosion Inhibitor Check this out! Similar to popular water displacement/lube products, but it contains NO silicone or kerosene based solvents. This makes it benign, so it can be used around food! Of course it also works really well on seized nuts and bolts, hinges etc. Two types available: Cat. NA-1022 125g Spray Pump $ .50 Cat. NA-1022 300g Aerosol Cat. NA-1024 (cannot be sent via post) 6 Cat. NA-1024 $ .95 9 GPO Mains and Earth Leakage Tester Make GPO installation and checking a breeze! Identifies problems with wiring, and checks earth leakage circuit breakers using Cat. QP-2000 selectable trip $ .95 current. like air conditioning, heating etc. •12V, 120 ohm coil. •Loads up to 7,500W. •High inrush capability 65A, 10,000V. Cat. SY-4040 $ .95 Silver Conductive Pen Cat. NS-3032 $ .95 33 IDEAL Non - Contact 60 to 400VAC 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. Cat. QP-2274 $ .95 29 Fourth Edition Learn all about satellite TV! It has 156 pages covering topics such as the history and evolution of satellite TV, components and dishes, encryption systems, as well as practical information on setting Cat. BV-1800 up satellite receivers, $ .00 and data. 292 x 207mm. 379 49 Neon Spark Plug Tester TAMIYA Model Tyres Ideal for model car robotics projects! Two types available: Cat. QP-2264 $ .95 5 Truck Tyres - Set of 4. Includes 4 x 36mm dia tyres, hubs to suit & Cat. YG-2860 2x100mm axles. $ .95 9 3 - 28V Wireless Auto Tester 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 Cat. QP-2212 $ .95 transducers etc. 29 Cat. AA-0580 $ .95 39 22F and 55F 2.5V Super Capacitors This is not a misprint! 22 Farad and 55 Farad super capacitors, specially engineered for high energy storage. Great for replacing bulkier secondary batteries in many circuits. See website for details. 22F Measures 12 x 25mm Cat. RE-6702 $ 55F Measures 18 x 40mm Cat. RE-6704 Teletaper - Telephone Audio Tool HKZ-101 Hall Effect vane The Practical Guide to Satellite TV Fantastic price! If you only use a CRO occasionally, then this model is suited for you. It has a host of great features that you would expect to see in a quality unit. Cat. QC-1910 $ .00 Record phone conversations! It is designed for use in call centres where a supervisor can listen to, or record the conversation. Caution: Not to be used on a public switched telephone network. NOT AUSTEL Cat. QC-1990 $ .95 APPROVED. Was $80 12.95 $ 19.95 SAVE $30.05 49 Precision Mini Metal Lathe Deal 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 $107.80 extra, costing over worth of parts $100 more, but are already included! included in the price! Was $899 Sports Tyres - Set of 2. Includes 2 x 56mm dia tyres, a set of wide and narrow hubs to suit, screws, nuts Cat. YG-2862 & two small $ .95 wrenches. FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 An affordable power supply for Luxeon LEDs! This pre-built module can power 1, 2, or 3 1W Luxeon LEDs from a DC supply of between 11 and 30V. 19 10MHz Single Trace Oscilloscope Great for rework and SMD! The solder itself is 63% Tin, 37% Lead, with a 9.5% flux. It eliminates the need for clumsy resin core solder on fine circuits. 80g syringe. Cat. NS-3037 $ .95 * Please ask sales staff for this product, as it is kept refrigerated. Pre Built Luxeon LED Power Module 7 Easy repairs! It is quick drying with a high silver content for superior corrosion resistance. 1.6mm trace width, 10 min drying time (typ). 19 Solder Paste Syringe 29 Jaycar has it back! Previously obsolete, the HKZ-101 has been commonly requested, but difficult to find since Siemens deleted it in 1998. This copy is Cat. ZD-1900 almost identical, and works very $ .95 well. See our website for data. 19 Simple tester for a simple problem. Don’t get caught with a faulty spark plug. Bright neon illumination indicates spark presence. 22 INTERNET> www.jaycar.com.au 16 Cat. TL-4000 $ .00 799 SAVE $100 7 Wireless Basketball Scoreboard Kit EXCLUSIVE TO JAYCAR! This kit enables you to make a full-sized electronic scoreboard, in particular for Basketball but also adaptable for netball and other games. Ref: Silicon Chip March/April/May 2005. It can be built for a fraction of the cost of commercial equivalents and has a completely wireless scoring console that can control one or multiple scoreboards. You can mount the scoreboards high up in a court and all you need is a convenient 240V power point. You can then control them from a table courtside with no messy wiring. It features Home/Away team scores 0 to 199, Game period, and Countdown time. The scoreboard measures 900 x 600mm. The Jaycar kit comes complete with all pre-cut scoreboard woodwork, screen printed face, display filters, mounting plates, pre-programmed microcontroller, printed circuit boards, 2.4GHz transmitters & receivers, pre-punched control console with special piezo end-of- Cat. KC-5408 $ .00 game/quarter sounder, and all electronic components to make one scoreboard. Wine Cooler Kit Voice Recorder Kit 799 MIDI Theremin Synthesiser Kit Exclusive to Jaycar! Ref: Silicon Chip April / May 05. Instead of generating a Theremin like tone, it relies on a MIDI accessible synthesiser or a computer with a sound card. When set up (usually with a computer), it will play up to 120 different instrument selections in 15 types, by 8 variations. There are loads of features and functions, too many to list here, so check out our website or the Silicon Chip articles for full details. Kit supplied with PCB, case, LCD, and all electronic components. Cat. KC-5410 $ .00 159 V8 Sounding Doorbell Kit A must for car Make a cheap wine cooler! Recording flexibility! enthusiasts! Ref: SC June 05. This Ref: SC May 2004. Record and Ref: Silicon Chip Jan ‘05. project uses turns a playback up to 60 seconds of Be the envy of your mates regular fridge or audio, all under the control of a as they hear the rumble freezer into a PC or microcontroller. Variable when they press your wine cooler by sampling rate allows quality doorbell. You may have seen commercially accurately controlling the selection, and more. Kit supplied with PCB, Cat. KC-5412 available units, but nothing like this. It sounds just like a V8, and temperature to make it voice recorder IC, and all electronic has variable background noise for tappets and valves etc, for an $ .95 suitable for wine storage. A much components. even more realistic effect. 2 versions available: cheaper option than commercial units. Kit supplied with PCB, case, mains Full V8 Doorbell Kit Supplied with PCBs, silk-screened and Cat. KC-5411 Bass Extender Kit plug & all electronic Cat. KC-5413 $ .95 machined case, push button bell switch, speaker, hook-up wire, $ .95 An extra octave of bass response! components. and all electronic components. Includes optional Cat. KC-5405 Ref: Silicon Chip April 2005. This project boosts the 120mm length of 100mm dia. pipe for that $ .95 YOUR LOCAL JAYCAR STORE level of bass to counteract the frequency roll-off extra rumble! of your loudspeaker enclosures, effectively giving NEW SOUTH WALES Short Form V8 Doorbell Kit you an extra octave of bass response. Kit Albury Ph (02) 6021 6788 Contains the working electronics only. Supplied includes PCB & all electronic components. Alexandria Ph (02) 9699 4699 Cat. KC-5406 with PCBs, and all electronic components. Bankstown Ph (02) 9709 2822 $ .95 Bondi Junction Ph (02) 9369 3899 No case, speaker, or pushbutton etc supplied. Brookvale Ph (02) 9905 4130 Theremin Synthesiser Kit Campbelltown Ph (02) 4620 7155 Far cheaper than commercial units! Erina Ph (02) 4365 3433 Ref: SC Aug ’00. The The SHORT CIRCUITS LEARNING SYSTEM Hornsby Ph (02) 9476 6221 Theremin Newcastle Ph (02) 4965 3799 The Short Circuits learning system is a great way to learn Synthesiser Parramatta Ph (02) 9683 3377 electronics. It is fun, informative, and you build great Penrith Ph (02) 4721 8337 produces those projects along the way. Here is just one from Short Circuits 2… Silverwater Ph (02) 9741 8557 familiar science St. Leonards Ph (02) 9439 4799 Simple FM Bug Kit fiction movie Sydney City Ph (02) 9267 1614 sound effects when you move your hand Move over 007! This little FM bug transmits to an everyday 88MHz Taren Point Ph (02) 9531 7033 Cat. KJ-8230 108MHz FM radio, and works surprisingly well. You can also use it as a between the metal plate and antenna. It Wollongong Ph (02) 4226 7089 $ .95 low-cost baby monitor and more. Kit includes PCB, and all electronic VICTORIA has an amazing range from shrieks to Coburg Ph (03) 9384 1811 components. Instructions are in the Short Circuits 2 book. growls, and is not just entertaining. The Frankston Ph (03) 9781 4100 Beach Boys used a Theremin in their Geelong Ph (03) 5221 5800 Universal +/- 15V Power Driveway Sentry Kit classic hit "Good Vibrations" Kit supplied Melbourne Ph (03) 9663 2030 Supply Kit with PCB, silk screened and Cat. KC-5295 No false alarms! Ringwood Ph (03) 9870 9053 Springvale Ph (03) 9547 1022 Great for preamps! machined case, metal plate, $ .95 Ref: SC Nov 2004. QUEENSLAND Ref: SC Aug ’88. antenna, speaker, Aspley Ph (07) 3863 0099 Also available Allows you to obtain all electronic Brisbane - Woolloongabba pre-built & tested +15V, -15V, and +/components. Ph (07) 3393 0777 Cat. AM-4025 $99 15VDC depending on Gold Coast - Mermaid Beach Ph (07) 5526 6722 configuration. Open garage doors or gates etc Cat. KC-5038 Townsville Ph (07) 4772 5022 5m IR Light Barrier Kit Includes PCB and automatically when you pull up in your $ .95 Underwood Ph (07) 3841 4888 Excellent functionality! electronic components. vehicle. It uses a sensitive coil assembly AUSTRALIAN CAPITAL TERRITORY This kit indicates via LED rather than IR beams etc., to eliminate Canberra Ph (02) 6239 1801 Car Turbo Timer Kit when the beam TASMANIA false alarms from debris and animals. Kit Save your turbo! Hobart Ph (03) 6272 9955 is broken. Includes supplied with PCB, silk screened It idles you car for a PCB, IR RX/TX diodes, SOUTH AUSTRALIA machined case, pre-wound Cat. KC-5402 set time after Adelaide Ph (08) 8231 7355 magnifying lens, and all Cat. KG-9094 and insulated 5000 turn coil, $ .00 ignition switch-off Clovelly Park Ph (08) 8276 6901 electronic components. $ .95 & all electronic components. WESTERN AUSTRALIA to aid in turbo Perth Ph (08) 9328 8252 cooling. Includes NORTHERN TERRITORY Performance Electronics for Cars Book PCB, case, relay, and Darwin Ph (08) 8948 4043 Over 160 pages! The Performance Electronics for Cars Book from all electronic NEW ZEALAND Cat. KC-5254 Silicon Chip publications has chapters on modification and theory, as components. Hamilton Ph (07) 846 0177 $ .95 Newmarket - Auckland well as the 16 projects. Here is just one… Cat. BS-5080 $19.80 Ph (09) 377 6421 PC IR RX/TX Kit Smart Fuel Mixture Display Kit Glenfield - Auckland Quick and easy! Ref: SC Dec ’01. Adapts Very informative! This fuel mixture display kit Ph (09) 444 4628 to PC motherboards that have provisions improves on our regular model, with the Wellington Ph (04) 801 9005 for on-board IR support. Includes PCB and addition of an emergency lean-out alarm, Christchurch Ph (03) 379 1662 all electronic components. Freecall Orders Ph 0800 452 9227 better circuit protection, and an auto-dimming Cat. KC-5323 Cat. KC-5374 display. Kit includes PCB, $ .95 $ .95 and all electronic components. 39 19 39 79 49 12 59 13 11 179 29 27 8 PRICES VALID TO END JUNE 2005 21 FOR INFORMATION AND ORDERING TELEPHONE> 1800 022 888 INTERNET> www.jaycar.com.au ALTERNATIVE POWER REGULATOR Here’s a cheap, simple shunt regulator that’s ideal for use with alternative power generation systems, whether they be wind, solar, hydro . . . you name it. It will prevent your batteries from being cooked by over-charging and can even assist with hot water or other heating. Article by Ross Tester siliconchip.com.au June 2005  61 H ave you decided to generate some power yourself? It’s becoming more and more popular these days, especially as politicians keep making noises about soaring energy prices – and alternative energy generation equipment keeps getting cheaper and cheaper. For most people, the choice is solar or wind generation. Not too many people have a sufficiently reliable stream running through their back yard; even less would be allowed to dam it to get the head required. And then what happens in a drought? Solar is practical pretty much anyware the sun shines, as long as there is a large enough area with a good solar exposure. However, it is still relatively expensive and we understand government subsidies have now all but disappeared. We looked at the economics of solar power in some detail – and generated some heat ourselves – back in March 2002. Unfortunately, wind generation is not exactly suitable for the quarter-acre block in the suburbs. Uninformed (dare we say ignorant?) councils don’t like the idea of towers being erected in the back yard nor do they like those big spinning things which can upset the neighbours. But for anyone in a windy area in the sticks, especially those off the electricity grid, generating your own power from the wind is most definitely a practical solution these days. In fact, we described just how to do that yourself using a modified washing machine motor in a series of articles between December 2004 and March 2005 (back issues of these or the March 2002 issue of SILICON CHIP are available at $8.80 each inc GST and p&p). In addition, several suppliers now have efficient, effective wind generation kits available. While, say, 250500W doesn’t sound all that much, if you are in a relatively constantly windy area, that is certainly enough to keep your batteries charged and give you power when you want it. Aaah, the batteries! It’s often the last thing would-be alternative energy generators think about. After all, actual generation is the most important part of the equation, right? Yes . . . and no! Sure, you need to be able to capture nature’s energy but what do you do with it once captured? Unless you have some means of storing that energy – ie, batteries – it won’t be available when you want to use it. So it is lost – and a lot of that money you have spent is just wasted. But you can’t just chuck any old battery, such as a car battery, into the system and expect it to work properly. For a start, you need batteries designed to operate with deep discharge and charge cycles. You’re probably going to need more than one battery, especially if you run a system delivering more than the “usual” 12V (and for best efficiency, you should). Deep discharge batteries are available – in fact, most manufacturers now make batteries specifically intended for alternative energy/energy storage applications. But they are expensive – much more so than the producedin-their-millions automotive batteries. (Car batteries are designed for a short, high current discharge which does not upset them too much, as long as they are recharged immediately – which of course they are, from the car’s alternator. Start deep discharging a car battery and its life will be measured in weeks, not years, as they normally are.) The other thing that upsets batteries, of any description, is incorrect charging. Sometimes it is insufficient charging but more often than not it’s over-charging. When a battery is over-charged, it heats up. Its electrolyte evaporates (sometimes, it actually boils away) and you’re left with a large, unattractive paper weight, permanently and terminally damaged. When you have spent hundreds (perhaps even thousands) of dollars on storage batteries for an alternative energy system, that hurts. It’s enough to make you cry! Our regulator That’s where this little circuit comes in. It simply won’t let your batteries be overcharged. Once they reach the fully charged state, it switches incoming current into a dummy load (or several dummy loads if you wish). While in the prototype shown here the heat generated is simply vented to air (with fan assistance) there is nothing to stop you using that otherwise wasted energy to, say, heat water. Depending on how much energy is dumped into the dummy load, you may not get too much of a temperature rise in the tank – but any increase is good and it’s much better than wasting the energy. Here’s the shunt regulator, mounted in a junk case with dummy loads and cooling fan. It’s just one possible arrangement. 62  Silicon Chip siliconchip.com.au 120k LINK FOR 12V 22k C Q1 2N5551 C B Q2 2N5551 22k B E V+ OPTIONAL FAN TERMINALS + ZD1 15V 12nF E Q6 SDP55N03L D G S Q7 SDP55N03L D G S Q8 SDP55N03L D G S Q9 SDP55N03L D G + – – 47k 100k 1 +5V 8 100 µF A 100k 6.8k 120k VR1 2k IC1 L4949 2 LED2 1 2 1k 7 12k 22nF K 10 µF IC2a 5 6 5 A 100 µF λ K 12k 14 12k 12 3 10k B D1 1N4148 B C 1M Q5* BUZ71 IC2: 4093B 9 IC2d 10 3.5 Ω LOAD† L2 3.5 Ω LOAD† L3 3.5 Ω LOAD† L4 S E C † PART JUG ELEMENTS – SEE TEXT + E A 100 µF – ZD2 15V D G S 7 GND V– * OPTIONAL: REQUIRED ONLY IF COOLING FAN CONNECTED 2N5551 K 2005 Q3 2N5551 K 8 SC  Q4 2N5551 11 4 10k A IC2c 13 IC2b 1k LEDS λ LED1 3.5 Ω LOAD† L1 V+ (TO STORAGE BATTERIES) 1N4148 C B E SHUNT REGULATOR A ZD1, ZD2 – BUZ71 K D + G S SDP55N03L D S G D The circuit mainly consists of a 5V regulator/comparator, some NAND gates and MOSFETS which switch in dummy loads. We’ll look at the dummy load (actually made with wire jug elements) shortly. At the heart of this circuit is a 5V voltage regulator (IC1, an L4949). Its claim to fame is that it has a very low dropout voltage but also has additional functions such as power-on reset and input voltage sense. In this design the voltage-sensing comparator section and the 5V regulator are used. The system voltage is sensed via the voltage divider across the supply/ batteries with VR1 adjusting the exact voltage as required. (The top two resistors are only used for 24V systems). When the voltage at the wiper of VR1 (and therefore pin 2, the input voltage sensor of IC1) falls below 1.24V, the open-collector output (pin 7) is internally pulled to 0V. Therefore the 10mF capacitor charges to 5V via the 1kW resistor between it and pin 7. This presents a logic “0” to the input pins of both of the Schmitt NAND gates IC2a and IC2b, resulting in a logic “1” at both their outputs. IC2c, another siliconchip.com.au Schmitt NAND gate, has its inputs connected to IC2a’s output, so it has a logic “0” at its output. This turns Q3 off, which turns Q4 on, resulting in a low voltage at the gate of MOSFETs 2, 3, 4 and 5. Therefore they remain off, which means no current can flow through the dummy loads. When the batteries are fully charged, the voltage at Pin2 of IC1 will rise above 1.24V, so the opposite of what is detailed above occurs: IC2a and IC2b’s outputs go low, IC2c’s output goes high, turning on Q3 and turning off Q4. The MOSFETs now have gate voltage and are thus turned hard on, resulting in current flow through the dummy loads. The circuit remains in this state until the battery voltage falls below your pre-set trip point. There are several other components in the circuit which we haven’t considered yet. We mentioned IC2b but nothing after it. When its output goes high, the 100mF capacitor at the input to IC2d discharges via the 10kW resis- tor and the forward-biased D1. IC2d’s inputs are therefore low, resulting in its output being high. This provides gate voltage for MOSFET 1 which in turn switches on and allows a 12V or 24V fan to run, cooling the dummy loads. This is done so that the fan itself doesn’t draw power from the batteries when it is not required. While only a small drain (most fans of this type are <100mA) it would be constant and therefore would be wasteful of power. Note too that the fan is only required if you are not doing anything else with the heat from the dummy load(s). Regulator’s regulator Transistors Q1 and Q2, in conjunction with zener diode ZD1 form a simple 13.8V voltage regulator for IC1, which has a maximum supply of 28V. It is quite possible that this limit would be exceeded in a 24V system so the low-cost regulator is included. On a 12V system the voltage regulator isn’t required because this circuit keeps the battery voltage within safe levels (the supply to IC1 pin 1 would June 2005  63 Q4 Q3 2N5551 2N5551 SDP55N03L Q9 + + 100 µF Q8 L1 ZD2 SDP55N03L L1 L2 D1 1M 12k 10k 10k 4148 15V 12k 15V 1 V+ L2 L3 2N5551 SDP55N03L Q7 22k K ZD1 1 100 µF K 12nF 22nF + IC2 4093B 12k 1k 100k 1k IC1 L4949 2k Q5 BUZ71 Q1 2N5551 Q6 Q2 47k 6.8k 120k VR1 + LED2 L3 L4 100 µF 10 µF + LED1 100k 120k 22k – + 12V USE L4 – FAN LINK FOR V– SDP55N03L simply be about 1.2V less than the battery voltage). However, if the battery voltage goes above 15.2V, the regulator comes into action supplying 13.8V to the IC. Finally, the two LEDs (LED1 and LED2) operate as part of the IC2 gate circuits to indicate charging and charged states respectively. While on the prototype these LEDs were mounted on the PC board, they would normally be extended out to a panel. Hysteresis Component overlay with the same-size photograph below. The link is only required for 12V operation and can be a resistor lead offcut. As we said before, VR1 sets the exact trip point at which the regulator comes into play. While it is normal practice to set a car regulator to deliver 13.8V, it appears that it is normal to set a storage system to a float charge of about 15V. The circuit has in-built hysteresis so that it doesn’t continually “hunt” around that 15V figure. Only when the battery voltage drops to about 14V (ie, about 1V below the trip point) will the circuit turn off and the load be disconnected. Construction Parts List – Shunt Regulator 1 PC board, 98 x 47mm, coded K222 2 3-way PC board mounting terminal blocks 1 2-way PC board mounting terminal block 4 3.5W dummy load (see text) 1 12V (or 24V) fan (optional – see text) Heavy duty red & black hookup wire for connection to battery Semiconductors 4 2N5551 NPN transistors (Q1-Q4) 5 SDP55N03L power MOSFET (Q6) 2 15V 400mW Zener diode (ZD1, ZD2) 1 1N4148 small signal diode (D1) 1 L4949 monolithic 5V voltage regulator and comparator (IC1) 1 4093 quad Schmitt trigger NAND gate 1 5mm red LED (LED1) 1 5mm green LED (LED 2) Capacitors 2 100mF 33V PC mounting electrolytics 1 10mF 33V PC mounting electrolytic 1 12nF (0.012mF) polyester 1 22nF polyester Resistors (0.25W, 5%) 1 1MW 2 120kW 1 47kW 2 22kW 2 10kW 1 6.8kW 64  Silicon Chip 2 100kW 3 12kW 2 1kW There’s not much to the assembly. As usual, start with the lowest-profile components (resistors, diodes) and then move onto the capacitors, transistors and MOSFETs and finally the ICs. Check resistor values with a digital multimeter if you aren’t sure of their values. If you are using IC sockets, make sure you get the notch the right way around! Use a resistor lead offcut to form the 12V link, if needed. The final components to be soldered in are the terminal blocks, the potentiometer and the LEDs. As we mentioned before, the LEDs would normally be mounted off the PC board – use some thin hookup wire or rainbow cable to make flying leads – but watch the polarity! The dummy load(s) The Oatley Electronics kit does not contain any dummy loads – because each installation is different, these are left up to you. The SDP55N03L MOSFETs provided have an “on” resistance of around 11mW and a current rating of 50A. For a dissipation of 0.5W in the MOSFET, a current of 7A can be passed without a heatsink. If a small (eg, clip-on) heatsink is provided, the power can be more; with a decent heatsink much more. However, you would soon start to run into problems with the thickness of the PC board tracks, even if solder-coated. We have specified the dummy loads to have a resistance of 3.5W. While you can buy high power resistors of this type, a much cheaper (and in fact better) alternative is to make your own from electric jug elements. These consist of a coil of coiled resistance wire, wound on a ceramic former. In their 240V electric jug incarnation, they have a DC (cold) resistance of about 34W. Naturally, we need a lot less than that in a 12V or 24V system. The elements we used were “Phoenix” brand, cat no EJ2, as found in most hardware stores and supermarkets. Oatley siliconchip.com.au A possible arrangement for the dummy loads – note the fan blowing cold air across them. The coils here have not been straightened nor doubled (as explained in the text). Electronics will also have these available for $2.50 each (probably cheaper than you can find elsewhere!). Even though the photos show coiled coils, you don’t need them, so remove the wire and stretch it out until it is straight. Twist the two ends of the wire together and find the midpoint. Using an electric drill on a slow speed, twist the two lengths of wire together over their entire length. Simply grip the two loose ends in the drill chuck, hold the opposite end firmly (a vyce is a good idea!) and hold the length reasonably taught as you turn the drill on. A couple of short bursts will twist the strands together nicely. As you halved the original 34W wire, that means each strand is about 17W. Now twisted together, those strands are effectively two resistors in parallel, so the length of wire is now about 8.5W. You need a bit less than half that length to get to around 3.5W. Connect one multimeter lead to one end of the wire and simply drag the probe along the wire until it reads 3.5W. Add, say, 20cm to this to allow for terminations. Wind this length back on to the ceramic former and terminate it under the screw terminals. Check again that you have about 3.5W (it doesn’t need to be spot on). As we mentioned before, it’s a shame to waste the energy you’ve generated so if you can, immerse the dummy load(s) in your hot water tank to use the energy there. Otherwise connect a suitable fan to the fan terminals on the PC board so that the heat is removed from the system. Setup All you need to do is monitor your battery voltage on charge and adjust VR1 so that the regulator kicks in when the battery voltage reaches the required maximum (usually 15V). Keep monitoring the voltage while the battery discharges and ensure that when it reaches 14V the regulator switches off. Our photograph shows four dummy loads mounted in a surplus steel case which conveniently had a 12V fan already fitted. A gutted, dead, computer power supply case (but keep its 12V fan) would also be ideal. We cut most of the mounting wires off the four modified jug elements and bent those wires out 90° to allow them to be mounted in a pair of 7-way mains terminal blocks (each second terminal used). These blocks were themselves mounted in the case to siliconchip.com.au allow maximum airflow from the fan. Of course, this is all academic if you decide to use the dummy loads as water heating elements in their own right! 24V systems We’ve described operation for a 12V system but 24V systems are probably more common than 12V. The reason is simple: higher voltage equals lower current; lower current equals less line losses. In fact, 48V systems are not at all uncommon; beyond this you are starting to get into the “danger Will Robinson!” area, especially for the handyman with little technical background. Like it or not, that’s precisely the sort of person who is most likely to be building an alternative energy power system! Construction and setup are the same for 24V systems as for 12V, with the exception of the “12V” link. This time, though, you’d be looking for a kick-in at about 28V and a SC dropout 1V less. Where from, how much? This project was designed by Oatley Electronics, who retain the copyright and PC board design copyright. Complete kits (with all on-board components but no dummy loads) are available from Oatley Electronics, PO Box 89, Oatley, NSW 2223 (Tel [02] 9584 3563, Fax [02] 9584 3561, website www.oatleye.com) for $26.00 inc. GST, plus P&P. Phoenix jug elements are available at $2.50 each. June 2005  65 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. Solar hot water controller This circuit functions as a control unit in a solar hot water system (HWS). The temperature at the top of the panels is compared with that in the tank and when the Sun shines brightly enough, the pump is switched on. Water continues to circulate through the panels for as long as the temperature in the panels is greater than that in the tank. Note that most solar hot water systems don’t require a circulator pump as the panels are mounted below the tank and the natural thermo-siphon effect is relied upon to circulate the water. However, in situations where it is more cost-effective to have the panels at the same level or higher than the tank, a circulator pump is required, hence the impetus for this design. The circuit includes an anti-freeze feature that starts the pump when the water temperature in the lower panel drops below 4°C. With the addition of a digital panel meter, it can also be used to monitor water temperature in multiple locations around the system. A series of LM335s (TS1-TS6) are used as temperature sensors. Controller operation is based around sensors TS1 and TS2, which measure the temperature in the tank and top of the second panel. One element of an LM339 quad comparator (IC1b) compares the voltages from these two sensors. A higher voltage on the inverting input (pin 6) than the non-inverting input (pin 7) signals a higher panel temperature. This causes the output of the comparator to swing low, switching on Q1 and energising the relay (RLY1). This in turn applies power to the pump. A 2.2MW resistor affords some positive feedback around IC1b, ensuring jitter-free relay switching. A second comparator (IC1a) in the package is used to monitor the temperature in the bottom of the first panel for the anti-freeze function. The inverting input (pin 4) is supplied with a 2.77V reference, whereas the non-inverting input is connected to TS3. As these sensors are calibrated directly in °K, they have an output of +2.73V at 0°C. Therefore, once the water in the panel drops to below 4°C (2.77V), the voltage at the non-inverting input will be less than the reference voltage and the comparator output swings low. This forward-biases D3 and switches on Q1, again energising the relay and starting the pump. A third comparator in the package (IC1c) is used to provide indication that the anti-freeze function has been activated (apart from the fact that the panels aren’t frozen!). If IC1a’s output goes low, the non-inverting input (pin 9) is pulled lower than the inverting input (pin 8) and its output goes low, turning on LED1. At the same time, current is drawn through the base of Q2, turning it on and providing positive feedback via the 100kW resistor to the inverting input. This causes the output to remain latched in the on (low) state, keeping the “anti-freeze” LED illuminated even after the pump has been switched off. To reset the circuit, switch S2 must be pressed, overriding the positive feedback from the comparator’s output. A digital panel meter (DPM) provides a convenient means of displaying water temperature at various points in the system. As well as the three sensors mentioned above, the author added three more sensors (TS4-TS6) just for monitoring purposes. The output from any of these sensors can be displayed on the DPM with the aid of a 6-position rotary switch (S1). The series chokes (L1-L6) and 100nF shunt capacitors are included to filter out RF interference, necessary because the controller is situated close to a ham radio antenna. In order to read degrees Celsius directly, the negative input of the DPM is offset with a 2.73V reference, corresponding to 0°C. This voltage originates from a REF50Z temperature-compensated precision reference. The 5V output from the reference (REF1) is divided down by trimpot VR1 and a string of resistors. The trimpot should be adjusted for precisely 2.73V between the negative input of the DPM and ground. If readout accuracy is non-critical, then REF1 can be replaced with a (cheaper) 5.1V zener diode. As shown, the circuit is powered from a small 24V centre-tapped transformer, with regulator REG1 giving a stabilised +12V output. Take care to ensure that all 240VAC wiring is properly terminated and insulated. The project can be be housed in a plastic instrument case that’s protected from the elements. Keith Gooley, VK5OQ via email. Issues Getting Dog-Eared? Keep your copies safe with these handy binders. REAL VALUE AT $12.95 PLUS P & P Available Aust, only. Price: $A12.95 plus $7 p&p per order (includes GST). Just fill in and mail the handy order form in this issue; or fax (02) 9979 6503; or ring (02) 9979 5644 and quote your credit card number. 66  Silicon Chip siliconchip.com.au The circuit of the solar hot water controller uses a series of LM335 temperature sensors (TS1-TS6) to monitor the temperatures in the tank and the various panels. Their outputs are monitored by comparators IC1a-IC1c which in turn control a pump via a relay. Keith G is this m ooley o winner nth’s o Peak At f the las LCR Meter siliconchip.com.au June 2005  67 Circuit Notebook – Continued Two basic motor speed controllers Here are two simple 12V DC motor speed controllers that can be built for just a few dollars. They exploit the fact that the rotational speed of a DC motor is directly proportional to the mean value of its supply voltage. The first circuit shows how variable voltage speed control can be obtained via a potentiometer (VR1) and compound emitter follower (Q1 & Q2). With this arrangement, the motor’s DC voltage can be varied from 0V to about 12V. This type of circuit gives good speed control and self-regulation at medium to high speeds but very poor low-speed control and slow starts. The second circuit uses a switchmode technique to vary motor speed. Here a quad NOR gate (IC1) acts as a 50Hz astable multivibrator that generates a rectangular output. The mark-space ratio of the rectangular waveform is fully variable from 20:1 to 1:20 via potentiometer VR1. The output from the multivibrator drives the base of Q1, which in turn drives Q2 and the motor. The motor’s mean supply voltage (integrated over a 50Hz period) is thus fully variable with VR1 but is applied in the form of high-energy “pulses” with peak values of about 12V. This type of circuit gives excellent full-range speed control and gives high motor torque, even at very low speeds. Its degree of speed self-regulation is proportional to the mean value of the applied voltage. Fig.1: a very simple motor speed controller based on a compound emitter follower (Q1 & Q2). Fig.2: this slightly more complicated circuit gives better low speed control and higher torque. Note that for most applications, the power transistor (Q2) in both circuits will need to be mounted on an appropriate heatsink. Ravi Sumithraarachchi, Colombo, Sri Lanka. ($50) CONTRIBUTE AND WIN! As you can see, we pay good money for each of the “Circuit Notebook” contributions published in SILICON CHIP. But there’s an even better reason to send in your circuit idea: each month, the best contribution published will win a superb Peak Atlas LCR Meter valued at $195.00. So don’t keep that brilliant circuit secret any more: sketch it out, write a brief description and send it to SILICON CHIP and you could be a winner! 68  Silicon Chip siliconchip.com.au Op amp building blocks Here’s a series of basic op amp circuits that have a multitude of uses as building blocks in larger circuits. They all use a minimum number of components and with one exception, component values are non-critical. All op amps are FET-input types such as the TL071/2/4 single/dual/ quad varieties and all diodes are small-signal 1N4148s. All circuits are derived from the basic function block shown in Fig.1, which we’ll refer to as a “MAX” function. Its operation is as follows; if the voltage applied to V2 is less than V1, the output of the op amp is close to the negative supply rail, reverse-biasing diode D1. The output voltage is then just V1, as seen through the 100kW resistor. Conversely, if V2 is greater than V1, the op amp’s output swings positive so that D1 is forward biased and the voltage at the inverting input of the op amp (and hence Vout) is equal to V2. For best results, V1 should be driven by a low-impedance source such as an op amp connected as a voltage follower. The value of the input resistor (shown as 100kW) is not critical. In addition, any circuitry connected to Vout should have an impedance greater than about 1MW. Reversing D1 gives a “MIN” function block (not shown), whose operation should be self-explanatory. Fig.2 shows a precision clipper, made by merging a MAX and a MIN function block. The signal at Vin is transformed to the signal at Vout by clipping it when it is greater than V1 or less than V2. As before, V1 should be driven by a low-impedance Fig.1 Fig.2 Fig.3 source and any circuitry connected to Vout should have an impedance greater than about 1MW. Fig.3 shows a precision full wave rectifier. Op amp A, resistor R1, and diode D1 form a half-wave rectifier (this part of the circuit is equivalent to a MAX function block with V2 equal to 0V). Op amp B is configured with resistors R2 and R3 to subtract the original input signal at Vin from twice the half-wave rectified signal, giving the full wave rectified signal at Vout. This circuit needs fewer matched resistors than some other designs. For linear operation, R2 and R3 should be equal. The value of R1 is not critical. Once again, V1 should be driven by a low-impedance source such as an op amp connected as a voltage follower. Fig.4 shows a precision 2-way signal selector. It is made from two MIN function blocks (op amps B and C), one MAX function block (op amp D), and an op amp wired as an inverter (op amp A). None of the resistor values are critical nor do they have to be matched to achieve linear operation. For best results, “select” should be driven by a source with an impedance of less than about 10kW and any circuitry connected to Vout should have an impedance greater than about 1MW. Andrew Partridge, Kuranda, Qld. ($50) Fig.4 siliconchip.com.au June 2005  69 A radio-control (RC) servo can be added to the colour sensor unit for a bit of fun. Here, the servo arm is used as a pointer to indicate which sweet is under the sensor. The dial is made from a CD-ROM and the servo itself is simply connected to the servo driver PC board. PICAXE COLOUR Recognition System Use a PICAXE micro and a state-of-the-art optoelectronic IC to create this low-cost colour recognition system. By CLIVE SEAGER A LTHOUGH COLOUR recognition systems are not new, until recently they would have been far too complex and expensive to feature in a PICAXE project. Texas Advanced Optoelectronic Solutions (TAOS) from Plano, Texas, have changed all that with their new line of low-cost colour light-to-frequency (LTF) converter ICs. The TAOS TCS230 LTF converter was selected for this project because it integrates all of the functions neces70  Silicon Chip sary for colour sensing into a single miniature 8-pin package, including a digital output for easy interfacing to our PICAXE microcontroller. The project consists of two individual PC boards that plug together to form a complete colour recognition system. The first of these is the Colour Sensor Module, which includes the TCS230 sensor and a handful of support components. Revolution Education is supplying this board preassembled, as the TCS230 is only available in a tiny surface-mounted (SOIC) package that would be difficult to solder by hand. The second PC board is a PICAXE08M Servo Driver. Although primarily designed to control servos in robotic projects, this board is also suitable for use with the Colour Sensor Module. In this article, we’ll describe how to assemble the Servo Driver board, as well as how to connect it to the Colour Sensor Module to build a complete colour recognition system. Naturally, we’ll also show you how to program it to recognise colours! TAOS TCS230 colour sensor What makes the TCS230 sensor unique in the optoelectronic world is the integration of the light sensing, signal conditioning and analog-todigital conversion (ADC) functions in siliconchip.com.au Fig.1: the complete circuit diagram for the Colour Sensor Module. 33kW resistors set the default conditions (high or low) for the sensor’s input pins. Information on the function of the S0 & S1 inputs (here set for 100% relative frequency scaling using two 33kW pullup resistors) can be obtained from the TCS230 datasheet. A Mosfet (Q1) is used to switch the LEDs via the “L” signal on the connector. Fig.2: there’s even less to the Servo Driver circuit. As the sensor’s interface is digital, it is connected directly to the PICAXE port pins (via the 10-way header). A series diode (D1) reduces the 4-cell battery pack voltage to a safe level (5.4V nominal) to power both the Servo Driver and Colour Sensor boards. a single IC. The output from the sensor is a square wave of a frequency that is directly proportional to light intensity (irradiance). This can be connected directly to a microcontroller, thereby enabling extremely simple, cost-effective siliconchip.com.au light sensing solutions. So how can the TCS230 be used to differentiate one colour from another? Well, the sensor includes an array of 64 light sensors (photodiodes), organised in an array of 8 x 8. In all, 16 photo- diodes have blue filters, 16 have red filters, 16 have green filters and 16 are clear (no filters). All 16 photodiodes with the same filter colour are connected in parallel, with only one of the colours (red, green, blue or clear) June 2005  71 Fig.3: the TCS230 sensor is contained in a tiny 8-pin surfacemount package. The package is manufactured from a transparent material, allowing light to reach the photodiode array. can be gained simply by counting the number of pulses over a given sample period (eg, 50ms). This can be achieved with the PICAXE-08M’s count command. The process for measuring the RGB light intensity from a sample can be simplified as follows: (1). Select red filters (S2=0, S3=0) (2). Count pulses for sample period (result = red value) (3). Select blue filters (S2=0, S3=1) (4). Count pulses for sample period (result = blue value) (5). Select green filters (S2=1, S3=1) (6). Count pulses for sample period (result = green value) How accurate is it? enabled at any one time. Two digital control lines are provided so that external devices (such as our PICAXE) can select between the four arrays. By enabling each of the arrays (colours) in turn and measuring the proportional light intensity falling on the sensors, a good approximation of the red-green-blue (RGB) content of the light source can be established. As white light is composed of these three primary colours, it’s a relatively simple task for the microcontroller to differentiate any colour across the spectrum. Selection of each of the photodiode arrays is achieved via the S2 and S3 digital input pins, as defined in Table 1. The output of the sensor is a square wave with the frequency directly proportional to the light intensity. Therefore, a reliable indication of intensity Most colour sensors vary in accuracy across the RGB spectrum and the TAOS TCS230 is no exception. In theory, the three RGB sensors should record an equal value for pure white light but in practice, they don’t. This problem can be addressed by performing a white balance test. Its purpose is to calculate a scaling factor to apply to each colour to correct the error. In the case of a video camera, for example, this makes the playback of the colours more accurate on a television screen. However, with a simple microcontroller colour detection system, it isn’t necessary to scale the readings, as we won’t be reproducing the colours elsewhere. We are simply interested in a threshold point for each colour. Therefore, if we account for the imbalance within the thresholds set for each colour by experimentation, no white Fig.4: the Colour Sensor Module is supplied preassembled but we’ve provided the overlay diagram here for reference. All you have to do is fit the two LEDs (and their “posts”) as shown in the photo above right. Links J1-J4 are left open for this project. 72  Silicon Chip Table 1: Filter Selection S2 S3 Filter 0 0 Red 0 1 Blue 1 0 None 1 1 Green balance test is required. However, for more advanced applications, a white balance test can easily be added to the program if required. Note that background lighting conditions and distance from the sample will also make a small difference to the readings, so you may need to recalibrate the sensor when moving its position. Colour sensor module As well as the TCS230 sensor IC, the Colour Sensor Module also includes its own light source in the form of two white LEDs. These are angled at 45° to provide a point of light to illuminate the sample. The reflected light is then focused by a small lens (as typically used in CCD cameras) onto the TCS230 chip. The lens also filters out unwanted background infrared light. The full circuit diagram for this module is shown in Fig.1 and the board overlay in Fig.4. These are included mainly for reference, as apart from the two LEDs, the board is supplied preassembled. Instructions supplied with the kit show how to install the LEDs. The most important point to remember is that the cathode (K) side of a LED is identified by its shorter lead and a “flat” side on the housing, as indicated on the circuit and overlay diagrams. In addition, the LED must be threaded into the right-angle post so that it will be angled towards the centre of the board when installed in the PC board holes. When testing the assembly later, note that you should check to make sure that the two LEDs are correctly aligned. Ideally, their light output should merge to produce a single light dot at a focal length of about 30mm from the PC board. If you have a “figure-8” light pattern instead, try tweaking the angle and position of the LEDs slightly. As the LEDs consume considerable power in comparison to the other parts of the circuit, battery life can siliconchip.com.au Fig.5: follow this diagram when assembling the Servo Driver board. In particular, check that you have the 33mF capacitors, diode (D1) and microcontroller (IC1) around the right way. The 10-way socket mounts on the opposite side of the board to the other components. be maximised by switching the LEDs on only when a “scan” is to take place. PICAXE control of the sensor As presented here, control of the Colour Sensor Module requires only three outputs and one input of a PICAXE microcontroller. A suitable circuit could be constructed on a prototyping board but a better way is to use a PICAXE-08M Servo Driver board for the job. This board includes a 10-way dual-row header socket to mate with the header on the Colour Sensor Module. Fig.2 shows the circuit diagram for the Servo Driver board. Output 0 of the PICAXE-08M controls the LEDs on the Colour Sensor Module, whereas outputs 1 & 4 connect to the TCS230’s S2 & S3 inputs to select the desired photodiode array (colour). Input 3 is connected to the TCS230’s frequency output. On the '08M chip, this leaves only one output (output 2) available for other uses. Naturally, if you require more input or output pins for a project, then the circuit and program is easily ported to the PICAXE-18X or 28X. If desired you could also leave the white LEDs permanently on, freeing up a PICAXE pin for use elsewhere (eg, connected to a pushbutton switch to activate sensing). Note that this board requires 6V (4 x AA cells) instead of the more usual 4.5-5V supply. This higher voltage is needed because typical RC servos require at least 6V in order to generate useable amounts of torque. A series diode (D1) drops the rail down to about 5.4V to power the PICAXE micro and the Colour Sensor Module, Table 2: Sample RGB Values Sweet Red Value Green Value Blue Value blue green 0<w4<50 50<w6<150 200<w5<350 0<w4<50 200<w6<300 100<w5<200 red 50<w4<100 20<w6<80 20<w5<100 yellow 150<w4<250 230<w6<350s 80<w5<120 siliconchip.com.au June 2005  73 Program Listings Listing 1 '****************************************************** ' PICAXE-08M input/output pins symbol LED = 0 symbol S2 = 1 symbol ser = 2 symbol CSI = 3 symbol S3 = 4 'colour sensor white LEDs (output 0) 'colour sensor select S2 (output 1) 'servo or serial LCD (output 2) 'colour sensor pulse (input 3) 'colour sensor select S3 (output 4) '****************************************************** ' Variables (w4-w6 uses b8-b13!) symbol red_value = w4 symbol blue_value = w5 symbol green_value = w6 'colour sensor red content 'colour sensor blue content 'colour sensor green content '****************************************************** ' Scan and display every second main: gosub colour 'scan the colour sertxd ("Red =", 9, #red_value, 9) sertxd ("Blue =", 9, #blue_value, 9) sertxd ("Green =", 9, #green_value, CR, LF) pause 1000 goto main '****************************************************** ' Sub to scan colours colour: high LED low S2 low S3 count 3, 50, red_value high S3 count 3, 50, blue_value high S2 count 3, 50, green_value low LED return 'LED on 'read red into w4 'read blue into w5 'read green into w6 'LED off Listing 2 servo 2, new_pos pause 1000 goto main 'move the servo '*********************************************** ' Sub to scan colours colour: high LED low S2 low S3 count 3, 50, red_value high S3 count 3, 50, blue_value high S2 count 3, 50, green_value low LED return 'LED on 'read red into w4 'read blue into w5 'read green into w6 'LED off '*********************************************** ' Sub to evaluate colour and then set the servo position evaluate: new_pos = 190 'preload reject position ' Now identify correct colour using the threshold values if red_value > 150 and red_value < 250 then test_yellow if red_value > 50 and red_value < 100 then test_red if red_value < 50 then test_blue_or_green return test_blue_or_green: if blue_value > 200 and blue_value < 350 then test_blue if blue_value > 100 and blue_value < 200 then test_green return test_blue: if green_value > 50 and green_value < 150 then is_blue return is_blue: new_pos = 170 return main: gosub colour 'scan the colour serout 2,N2400,(254,128,"R=",#red_value, " ") serout 2,N2400,(254,136,"B=",#blue_value, " ") serout 2,N2400,(254,192,"G=",#green_value, " ") pause 1000 goto main test_green: if green_value > 200 and green_value < 300 then is_green return Listing 3 test_red: if blue_value > 20 and blue_value < 100 then test_r2 return '****************************************************** ' PICAXE-08M input/output pins symbol LED = 0 symbol S2 = 1 symbol ser = 2 symbol CSI = 3 symbol S3 = 4 'colour sensor white LEDs (output 0) 'colour sensor select S2 (output 1) 'servo (output 2) 'colour sensor pulse (input 3) 'colour sensor select S3 (output 4) '****************************************************** ' Variables (w4-w6 uses b8-b13!) symbol new_pos = b1 symbol red_value = w4 symbol blue_value = w5 symbol green_value = w6 'new servo position 'colour sensor red content 'colour sensor blue content 'colour sensor green content '****************************************************** main: gosub colour 'scan the colour gosub evaluate 'set the servo position 74  Silicon Chip is_green: new_pos = 90 return test_r2: if green_value > 20 and green_value < 80 then is_red return is_red: new_pos = 145 return test_yellow: if blue_value > 80 and blue_value < 120 then test_y2 return test_y2: if green_value > 230 and green_value < 350 then is_yellow return is_yellow: new_pos = 120 return siliconchip.com.au Fig.6: the output from the test program, as it appears in the Programming Editor’s serial terminal window. which have a maximum input voltage of 5.5V. Assembling the servo driver Assembly of the PC board is very straightforward. Install the low-profile components first, starting with the resistors. When installing the two 33mF tantalum capacitors, make sure that you have their positive (+) leads oriented as shown (see Fig.5). Also, take care that you have the PICAXE08M (IC1) around the right way; the notched (pin 1) end must be next to the programming socket. Leave the 10-way socket until last. It must be mounted on the opposite side of the board to all the other components (see photos) so that it can mate with the corresponding header on the colour sensor module. Once assembly is complete, fit 4 x 12mm threaded spacers in each corner mounting hole using the supplied M3 x 6mm screws. The colour sensor module can now be plugged into the servo driver’s socket and a further 4 x 30mm spacers fitted as legs to support the whole assembly. You should end up with a “tower”, as shown in the lead photograph. Testing To check that your completed unit is working properly, a simple program can be run to “learn” the reflected light properties of various samples. We’ve used some small sweets as samples but you can use what ever you have on hand. Note that you may need to adjust the height of the tower to compensate for the height of your samples. The test program is shown in Listing 1. You can type this into the Programsiliconchip.com.au ming Editor directly or download it from the SILICON CHIP website at www. siliconchip.com.au. Download and run the test program in the PICAXE-08M and then go to the terminal menu (via PICAXE -> Terminal from the toolbar) and choose a baud rate of 4800. The terminal window will then display the RGB data being output via the sertxd command. If you wish to perform the testing away from your computer, you can use a serial LCD module (Part No. AXE033) connected to output 2. Listing 2 shows the “main” section of the program altered to support a serial LCD module. Par t s Lis t For AXE024 Servo Driver Colour identification Capacitors 2 33mF 16V tantalum 1 100nF MKT polyester Table 2 shows a list of values for each of the sweet colours that were determined by experimentation. Note that we’ve used very broad thresholds to allow for the variations seen with even slight movements of the sweets from measurement to measurement. Regardless of the broadness of our figures, the important point is that each colour of sweet can be uniquely identified from these values. The third program adds a radiocontrol type servo for a bit of fun. The servo arm is used as a pointer to indicate which sweet is under the sensor. A simple dial is made from a blank CD-ROM, which is then placed under the servo arm. The servo itself is simply connected to output 2 of the PICAXE chip. This time, the program is a little more involved as it has to determine which sweet is which colour using mathematical comparisons. This is achieved by testing the threshold values for each of the RGB values in Table 2. Summary The TCS230 light-to-frequency 1 Servo Driver PC board 1 3.5mm stereo socket 1 battery clip 1 4 x AA battery holder 1 8-pin IC socket 1 10-way 2.54mm (0.1-inch) SIL header (separate into 3 x 3-way headers) Semiconductors 1 PICAXE-08M microcontroller (IC1) 1 1N4001 diode (D1) Resistors (0.25W 5%) 1 22kW 1 10kW 3 330W Also required (not in kit) PICAXE Programming Editor software (v4.1.0 or later) PICAXE download cable (Part No. AXE026) 4 x AA alkaline cells 1 Colour Sensor Module (Part No. AXE045) 1 10-way 2.54mm (0.1”) pitch DIL header socket Mounting hardware (standoffs, screws) converter is an economical solution for many colour-sensing projects. It is easily interfaced to a PICAXE microcontroller and is a versatile sensor that can be incorporated into many mechatronic and robotic applications. More information on TAOS sensors can be obtained from their website at SC www.taosinc.com. Obtaining Kits & Software The design copyright for this project is owned by Revolution Education Ltd. The Colour Sensor Module can be purchased individually (Part No. AXE045) or as part of a kit (Part No. AXE112S). The kit includes a PICAXE Servo Driver kit (Part No. AXE024), a 10-way header socket and the mounting hardware necessary to allow the boards to be stacked together. All items are available from authorised PICAXE distributors – see www.microzed.com.au or phone Microzed on (02) 6772 2777. The PICAXE Programming editor software can be downloaded free of charge from www.picaxe.co.uk or ordered on CD (Part No. BAS805). June 2005  75 By Clive Seager* Last month, we assembled our Schools Experimenter board, installed the Programming Editor software and ran a simple test program. This month, we’ll look at how to write programs that respond to input signals. In this article you will learn: how to write a program that responds to digital inputs; • the difference between a digital and analog input; and • how to write a program that responds to analog inputs. • Inputs and outputs The PICAXE-08M microcontroller has five pins available for use in your circuits (see Fig.1). Of these, pins 1, 2 and 4 can be used as outputs, digital inputs or analog inputs. On the experimenter board, pins 1 and 2 are used as outputs to drive the yellow and green LEDs, whereas pin 4 is used as an analog input for the light dependant resistor (LDR). * About the author: Clive Seager is the Technical Director of Revolution Education Ltd, the developers of the PICAXE system. 76  Silicon Chip Pin 0 can only be used as an output. In addition to driving the red LED, it is used for communications when downloading a program from your computer into PICAXE memory. It is useful to remember that this output toggles rapidly (as is evident by the flickering of the red LED) during program downloads. Lastly, pin 3 can only be used as a digital input. On the experimenter board, this input is connected to the pushbutton switch (SW1). Important: in the PICAXE system, the physical pins of the microcontroller are often referred to as “legs”. On the other hand, port inputs and outputs are called “pins”. For example, on the PICAXE-08M, pin 2 is input2 (or output2 or ADC2) and appears on leg 5 (see Fig.1). Getting started Even those of us who don’t drive a Fig.1: the pinouts for the PICAXE-08M microcontroller, as used in the Schools Experimenter board described in Pt.1 last month. siliconchip.com.au Fig.2: a pushbutton switch generates a digital signal with the aid of a 10kW “pulldown” resistor. Fig.3: when connected in a simple potential divider circuit, an LDR generates an analog signal proportional to light intensity. motor vehicle will be familiar with the red - green - orange - red sequence of traffic lights. The BASIC program to simulate a traffic light sequence on the PICAXE experimenter board is shown in Listing 1. Of course, we’ve used the yellow LED in place of orange and we acknowledge that where you live, the sequence might be slightly different, so jump right in and change it to suit! Note the use of the symbol command at the start of the program. Symbol can be used to make a program easier to understand, as you do not have to remember which LED is connected to which output. As you would expect for a traffic light simulator, the program runs continuously in a loop, starting as soon siliconchip.com.au Fig.4: As light intensity decreases, the resistance of the LDR increases, so a greater portion of the supply voltage appears across its terminals. Conversely, the voltage at the PICAXE’s analog input decreases, as a smaller portion is dropped across the 10kW resistor. as the battery is connected. But what if you only want the outputs to come on when a switch is pushed? A realworld example of this can be seen in a washing machine, where it’s necessary to push the “Start” button to initiate a wash cycle. Digital inputs A miniature pushbutton switch is included on the experimenter board and it’s connected to input3 of the micro. Fig.2 shows the components used in the switch circuit. As you can see, it’s very simple; just the switch and a 10kW resistor connected in series between the 4.5V and 0V power supply rails. The 10kW resistor performs an important function. Without it, the PICAXE input would not be connected to any electrical signal when the switch is open, causing it to “float” to an indeterminate logic state. How- ever, with the 10kW resistor in place, the input has two definite states: 0V when the switch is not pushed and 4.5V when the switch is pushed. In digital electronics, these two states are referred to as a “low” (logic 0) and a “high” (logic 1), respectively. A BASIC program that demonstrates how to respond to the switch input is shown in Listing 2. In this program, the green LED will come on every time the switch is pushed (closed). Task – write a program to make the LED come on when the switch is open (rather than closed). Responding to multiple inputs Making the program react to two (or more) switches is also quite straightforward. By way of example, Listing 3 adds a second (hypothetical) switch on input4. As shown, the LED will be illuminated when either of the switches is closed. June 2005  77 Program Listings Listing 1 symbol red = 0 symbol yellow = 1 symbol green = 2 main: high red pause 500 low red high green pause 500 low green high yellow pause 500 low yellow goto main Listing 2 loop: if input3 = 1 then main goto loop main: high 2 pause 500 low 2 goto loop Listing 3 loop: if input3 = 1 or input4 = 1 then main goto loop main: high 2 pause 500 low 2 goto loop Listing 4 loop: if input3 = 1 and input4 = 1 then main goto loop Listing 4 shows how the program is easily modified to react only when both switches are closed at the same time. TASK – write a program to make the LED come on when two switches (on input3 and input4) are pressed together or when a switch on input1 is pressed by itself. Waiting until a switch is released Sometimes it is necessary to wait 78  Silicon Chip the switch has been pushed and then released. Adding switch debouncing main: high 2 pause 500 low 2 goto loop Listing 5 loop: if input3 = 1 then loop1 goto loop loop1: pause 10 if input3 = 1 then loop1 main: high 2 pause 500 low 2 goto loop When most mechanical switches close, two sprung metal contacts move closer together and then eventually touch. Unfortunately, these contacts do not move precisely and quite often “bounce” against each other a couple of times before coming to a stop. This means that the electrical connection opens and closes rapidly a number of times whenever the switch is activated. A PICAXE microcontroller processes much faster than a mechanical switch can operate and so will detect the switch “bouncing” as legitimate on/off switch action. By adding a 10ms delay into the loop (the pause 10 command in Listing 5), we provide the switch contacts with time to settle before the program reads the switch input and makes the on/off decision. Analog inputs Listing 6 main: readadc 4,b1 debug b1 pause 100 goto main Listing 7 symbol action = 80 loop: readadc 4,b1 if b1 < action then main goto loop main: high 2 pause 500 low 2 goto loop until a switch is pushed and then released before continuing the program. In this case, the program in Listing 5 can be used. As in the previous examples, the program waits in a loop until the switch is pushed. However, it then jumps to “loop1” where it waits until the switch is released again before continuing. This means that the “main” section of the code is processed only after As we’ve seen, a pushbutton switch is essentially a digital device, as it has only two states (on or off). However, some sensors, such as light and temperature sensors, generate a continuously varying signal. These varying signals are called analog signals. Input4 on the Schools Experimenter board is connected to an LDR and 10kW resistor (see Fig.3). These two components are connected in series between the +4.5V and 0V power supply rails, forming a “potential divider”. This term refers to the fact that each of the components has a fraction of the 4.5V supply across it, in effect dividing the supply voltage. As more light falls on the LDR, its resistance decreases, meaning that a smaller percentage of the 4.5V supply will appear across it. Therefore, it follows that the voltage reading at the PICAXE input will vary according to how much light falls on the LDR. The general idea is explored in Fig.4, where three arbitrary light levels produce different resistance values and correspondingly different voltage levels. The PICAXE chip can measure this varying voltage using the readadc command. Readadc is shorthand for “read-analog-to-digital-converter”. This command instructs the PICAXE to read the analog voltage value and then save that value as a number in memory. As the PICAXE works with siliconchip.com.au byte values, the result will always be a whole number between 0 and 255. In the simplest possible terms, if you connect 4.5V to the input, you will get the number 255 in your program. Connect 0V to the input and you will get the number 0. Connect any voltage between these two values and you will get a number between 0 and 255, which in our case can then be used as the “light level” reading. Task – what values would be returned by the readadc command with input levels of 2V, 3V and 4V? The program in Listing 6 reads the analog level on input4 and stores the value in variable byte 1 (b1). The debug command then transmits this value via the serial cable to your computer screen every 100ms. Run this program and then vary the light levels reaching the LDR using your hand. You should see the value of variable b1 change as the light falling on the sensor changes. Make a note of the “bright” light level value (sensor exposed) and the “dark” value (sensor obscured). Use these values to decide on an “action threshold”, which should be about halfway between these two values. Silicon Chip Binders REAL VALUE AT $12.95 PLUS P & P This is the basic Schools Experimenter board described in Pt.1 last month. The program in Listing 7 uses an action threshold value of 80, which you can change to suit your experimental value. When the light level is less than the action level, the green LED will light. Task – write a program to make the LED come on when the light level is below your action value and the pushbutton switch is pressed. What’s coming That’s all for this month. Next month, we’ll look at a more sophisticated sensor for temperature measurement and have some fun with tunes SC using the piezo sounder. H Each binder holds up to 12 issues H S ILICON C HIP logo printed on spine & cover H Heavy board covers with mottled dark green vinyl covering Price: $A12.95 plus $A5 p&p each (available only in Australia). Buy five and get them postage free. 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. From the publishers of SILICON CHIP PERFORMANCE ELECTRONICS FOR CARS NOT A REPRINT: More than 160 pages of new and exciting projects never published before – all designed to get top performance from your car. FASCINATING ARTICLES: 7 chapters explaining your car – engine management, car electronics systems, etc ADVANCED PROJECTS: You’ll build controllers for turbo boost, nitrous, fuel injection and much more! We explain the why as well as the how to! Available direct from the Publisher ($22.50 inc postage): Silicon Chip Publications, PO Box 139, Collaroy NSW 2097. Ph (02) 9939 3295; Fax (02) 9939 2648; email silchip<at>siliconchip.com.au or via our website: www.siliconchip.com.au siliconchip.com.au June 2005  79 SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ SILICON CHIP If you are seeing a blank page here, it is more than likely that it contained advertising which is now out of date and the advertiser has requested that the page be removed to prevent misunderstandings. Please feel free to visit the advertiser’s website: www.altronics.com.au/ Pt.1: By ED SCHOELL* Managing Director, JED Microprocessors Pty Ltd. AVR200 Single Board Computer Professional engineers, students and hobbyists alike will appreciate this lowcost, high-performance development board from JED Microprocessors. J ED MICROPROCESSORS are an Australian company situated in Boronia, Victoria. Over their 25-year history, JED has produced a wide range of boards for the industrial and scientific sectors. Thousands of their single board computers are in use in applications as diverse as traffic monitoring in Victoria to penguin weighing in the Antarctica. Although relatively low in cost, this new design boasts high performance and ease-of-use that will prove adaptable to an endless variety of applications. It is based on the Atmel ATmega32 microcontroller which features an 8-bit RISC architecture 84  Silicon Chip that’s designed for efficient programming in high-level languages such as C and BASIC. What’s on the board As mentioned, an ATmega32 microcontroller forms the heart of the AVR200 design. JED has chosen the 40-pin dual-in-line packaged device rather than the 44-pin surface-mounted variant. In fact, all parts on the board are through-hole mounting, so that the board is easy to assemble. The board’s architecture is very simple, with the majority of the micro’s four 8-bit ports available for external interfacing. A handful of more complex functions such as serial I/O and I2C are supported by dedicated hardware. A screw terminal block at one end of the board accepts DC power (6-18V) for the on-board +5V regulator. Adjacent to this is a reset switch for the micro, while on the opposite side of the board are the serial communications connectors, comprising a D9 socket for the RS232 interface and a 10-way header for the I2C bus. Rows of screw terminal blocks along the top and bottom edges of the board provide easy access to the microcontroller’s ports. In the standard configuration, eight lines function as analog inputs or digital inputs/outputs. A further 11 lines act as digital inputs, while nine drive power Mosfets to provide open-drain outputs. All port pins used as inputs include over-voltage protection. If the standard configuration is not suitable for your application, then in most cases, ports can be swapped from siliconchip.com.au inputs to outputs or vice versa with only minor component changes. Atmel AVR micro The ATmega32 is a mid-level microcontroller in the AVR range and has 131 instructions, most executing in just one clock cycle. The board is normally supplied with a 3.6864MHz crystal but frequencies of up to 16MHz are supported. The RF energy radiated from the board is comparatively low, due mainly to the on-board filtering components and the lack of external high-speed buses. There are 32 user registers as well as 2Kb of user RAM. Six of these registers can be combined to form three 16-bit pointers, all supporting autoincrement/decrement with indirect and indexed addressing modes (the advantages of the AVR over architectures like the 8051 and PIC are immediately apparent when looking at this internal structure). Included on the chip are 32Kb of FLASH (program) memory and 1Kb of EEPROM. The FLASH memory can be loaded from a programming adapter (such as the AVR-ISP) or via the serial port of a PC using a boot loader. This will be described in more detail later. Major peripherals included in the ATmega32 are as follows: • UART for serial communications (RS232, RS485 or TTL level); (TWI), identical • Two Wire Interface to the Philips I2C system; • Serial Peripheral Interface (SPI), which allows two-way clocked data transfer; • Two 8-bit and one 16-bit counter with prescalers, capture/compare functions and PWM outputs; • Four 8-bit multifunction input/ output ports; • Watchdog timer. Note: the operation of the Atmega32 microcontroller is far too complex to be described in any detail in this short article. Readers not already conversant with this device can download the datasheets from www.atmel.com Let’s examine each of the I/O ports in detail and look at the various options available for the AVR200 hardware. The accompanying circuit diagrams are split into three sections due to size constraints. Fig.1 shows ports A & B as well as the voltage regulator, line filters and the optional high-resolution voltage reference. Fig.2 shows port C, siliconchip.com.au Basic Specifications • • • • • • • • • High performance ATmega32 AVR RISC microcontroller Easy-to-assemble design (no surface mounted devices) Four 8-bit input/output (I/O) ports, configured as follows: - 8 analog inputs or digital inputs/outputs - 11 digital inputs - 9 Mosfet (open drain) outputs - RS232 serial port - optional RS485 port - buffered I2C port - battery-backed real-time clock Highly customisable (ports can be reconfigured) Screw terminal connections High quality, plated-through PC board with solder mask Over-voltage protection for all inputs Small size (only 110 x 90mm) Supports “upstairs” expansion/prototyping boards the real-time clock and the buffered I2C interface. Finally, Fig.3 shows port D and the RS232 serial interface. Port A – analog inputs The ATmega32 has a powerful analog input system, incorporating an 8-channel, 10-bit resolution analog-todigital converter (ADC). Each channel is brought out to screw terminal blocks (J2 & J3), one of which also provides a +5V connection for external interface circuits, where required. Each channel incorporates a 7-way socket strip (L4-L11) that’s positioned between the micro’s inputs and the terminal blocks. The strips can be loaded with various components to perform a range of basic signal-conditioning functions. These include over-voltage protection, voltage scaling, high-pass filtering, etc. The various possibilities are shown in Fig.4. In summary, these are: • A simple series resistor (Rs, usually 10kW) for protecting a port input (Fig.4a); • A pull-up resistor (Rpu) to Vcc, used with resistive transducers to ground (Rs is still required) (Fig.4b); • A termination resistor to ground (Rpd) for a current loop input (eg, a 200W resistor converts a 4-20mA current loop to a 4V signal). Note that resistor Rs is still required (Fig.4c); • A series resistor (Rs) and a filter capacitor (Cf) to ground for signal smoothing (Fig.4d); or • A voltage divider configuration using Rs and Rd (Fig.4e). All port A inputs are protected against over-voltage conditions using Texas Instruments TL7726 hex clamping devices (U5 & U6). These devices limit the voltage range on the port pins to between Vcc and ground (± 200mV when sinking 25mA). ADC reference The full-scale voltage range of the ADC depends on the chosen reference voltage. This can be +5V (Vcc), an internal +2.56V reference or an external +4.096V adjustable reference. The latter is provided by an optional MAX874CPA precision voltage reference (U4). VR1 allows this to be set accurately using a digital voltmeter. The typical temperature coefficient for the MAX874CPA is 20ppm/°C, which is less than 1 LSB of conversion error over a 40°C range. This degree of precision is not possible with the internal reference, which can vary from 2.3-2.7V and has no quoted temperature coefficient. When using +5V as a reference, be aware that its absolute value can vary between 4.75V and 5.25V. Although large, this variation can be acceptable in certain applications (eg, when making ratiometric measurements). Port A – digital I/O The Atmega32 supports both analog inputs and digital I/O on port A. The June 2005  85 86  Silicon Chip siliconchip.com.au desired mode of operation is selected under program control. Therefore, the same connectors (J2 & J3) can provide analog inputs, digital inputs or digital outputs. Again, components must be installed in the 7-way socket strips to suit the chosen mode. If the port is used as digital inputs, resistors similar to the analog modes above can be installed, as follows: • A series resistor (R s, usually 10kW) for protecting a port input – see Fig.4a; • A switch or (external) optoisolator input with pull-up resistor (Rpu) to +5V (Fig.4b). • A pull-down resistor to ground (Rpd). This allows voltage inputs of 5 -12V to be sensed, with over-voltage protection limited by the dissipation of Rpd (Fig.4c); and • A voltage-divider configuration with Rs and Rd. Peak over-voltage protection of hundreds of volts is provided in this way (dissipation is limited by Rs) – see Fig.4e; If Port A is to be used as digital out- Where To Buy A Kit Kits and options for this project will be available from JED Microprocessors Pty Ltd, 173 Boronia Rd, Boronia, Vic, 3155. Ph (03) 9762 3588. Or visit their website at: www.jedmicro.com.au puts, all that’s required is a low value series resistor (Rs) of 100W or less to limit the short-circuit current. The output voltage swing is 0-5V, with several milliamps of drive current. Note that LEDs can easily be driven using Rs as a current-limiting resistor. If more current is needed from Port A, then the socket strips can be omitted during assembly and eight 4.7kW resistors and MDT3055 N-channel power Mosfets installed in their place, as shown in Fig.4(f). Port B – SPI interface The Serial Peripheral Interface (SPI) Fig.1: the ATmega32 microcontroller features four 8-bit ports for external interfacing tasks. Ports ‘A’ & ‘B’ are shown here, with ‘C’ and ‘D’ on following pages. Port A can support analog inputs or digital I/O and is highly configurable via 7-way socket strips (L4 – L11). Port B is typically configured for digital inputs. siliconchip.com.au June 2005  87 Fig.2: six bits of port C (PC2 – PC7) drive power Mosfets to provide high-current open-drain outputs. The lower two bits (PC0 & PC2) are used by the TWI (I2C) interface for peripheral expansion. 88  Silicon Chip siliconchip.com.au is a 3-wire interface that enables synchronous data transfer between the ATmega32 (in “master” mode) and any number of peripheral devices. It can also be used for micro-to-micro communications, where one operates in master mode and the other in slave mode. The SPI supports all industrystandard modes as well as variable bit rates, MSB or LSB first transfers and interrupt generation on transfer complete. Three pins on port B are used for the SPI: PB5 is “MOSI” (Master Out Slave In), PB6 is “MISO” (Master In Slave Out) and PB7 is “SCK” (Serial Clock). These signals are made available on connector J13. This connector also brings out port pins PB1-PB4, which can be used as “enable” signals for peripherals. A secondary function of the SPI port comes into play when the micro’s RESET line is active. In the reset state, the SPI operates as a serial programming interface, allowing direct programming of the micro’s FLASH memory (from a PC, for example). To this end, connector J13 has been specially modified to allow connection of a 6-pin Atmel STK500/AVR-ISP programming cable. A gap of four missing pins allows the 6-pin cable header to fit onto the first six pins of the connector. Connector J13 is also intended to allow connection of a prototype or project board with SPI-interfaced peripherals or direct port-driven I/O. Add-ons like this can be connected via a ribbon cable or mounted “upstairs” on a satellite board such as the AVR202. Port B – digital I/O As an alternative to the SPI functions mentioned above, all bits of Port B are also available for generalpurpose I/O. In the standard configuration, all eight bits are digital inputs but bits 0-3 (PB0-PB3) can also be configured as power Mosfet outputs using optional components. If PB0-PB3 are to be used as inputs, a 6-way socket strip is installed in the RP5 position to accept a 4 x 4.7kW 5-pin resistor pack. The end pins of the socket are at +5V and ground, so depending on the orientation of the resistor pack, the four port lines may be pulled down to ground or pulled up to +5V. In addition, a 4 x 4.7kW 8-pin resistor pack must be installed in locasiliconchip.com.au tion RP15. These series resistors are designed to provide current limiting for the TL7726 hex clamping devices (U5 & U6) during over-voltage conditions. Note that configuring bits 0-3 as inputs also enables the use of several special on-chip functions. Refer to the ATmega32 datasheets for detailed information. On the AVR200, bit 2 (INT2) can be linked via jumper L12 to the programmable square-wave output from the real-time clock. Alternatively, if PB0-PB3 are to be used as outputs, Mosfets F1-F4 are installed together with four gate pull-down resistors. The resistors go into location RP1 as a 4 x 4.7kW 5-pin resistor pack. Note that this configuration is optional and therefore the Mosfets and the resistor pack are not supplied in the standard kit. Any optional items can be ordered separately from JED. If PB4-PB7 are to be used as inputs, resistor packs RP6 (4 x 4.7kW 5-pin) and RP7 (4 x 4.7kW 8-pin) are installed, along with four zener diodes (Z6-Z9) for over-voltage protection. As described previously for the lower port lines, resistor pack RP6 provides either a pull-up or pull-down function, depending on how it is oriented in its socket strip. Port C – TWI (I2C) The Two-Wire Serial Interface (TWI) is used for peripheral expansion, both on the AVR200 board (eg, the real-time clock), “upstairs” to add-on boards via connector J14 and off-board via connector J6. The hardware for this interface is contained within the micro and is fully programmable. Two pins on port C are used for the TWI: PC0 is “SCL” (the clock line) and PC1 is “SDA” (the bi-directional data line). Both the CodeVision C and BASCOM BASIC compilers support this interface. Peripherals on the AVR200 and upstairs boards connect directly to the micro’s TWI lines. Both lines are pulled up to +5V with 1.5kW resistors, while zener diodes (Z1 & Z2) protect the internal bus and the micro from over-voltage transients. Normally, off-board TWI communications are buffered with U11, a PCF82B715 “times-10” current multiplier. This allows the TWI bus to extend some distance from the board via header J6 and low-cost 10-way ribbon Pin Function Pin Function 1 3 5 7 9 +5V Buffered SCL Buffered SDA INT0 INT1 2 4 6 8 10 +5V ground ground ground ground Table 1: pin-outs for the TWI (I2C) bus header (J6). The internal header (J14) has the pin-outs but note that it is non-buffered. cable. EMC filters with transient voltage suppressors (LC4 & LC5) protect these off-board connections. The TWI bus appears on header J6 along with two +5V power lines, four ground lines and two interrupt lines (INT0 & INT1). The pinouts for J6 are shown in Table 1. If it is necessary to communicate with non-buffered external devices, the buffer chip (U11) is simply omitted and links L24 & L25 are bridged to connect the SDA and SCL signals to the outside world. In addition, R9 & R10 are omitted and R11 & R12 should be 100W rather than 10W. Port C – real-time clock A Dallas DS1307 real-time clock chip (U7) provides time and date information over the TWI bus. This chip fits underneath the microcontroller and operates with a 32kHz watch crystal. A small lithium cell provides back-up when the power is off. With link L12 installed, the clock chip can provide a square wave signal of 1Hz, 4kHz, 8kHz or 32kHz on INT2 (PB2). The DS1307 includes 56 bytes of non-volatile RAM, also accessible over the TWI bus. Port C – digital I/O The standard configuration for port C bits PC2-PC7 is as outputs. Six MTD3055VL power Mosfets (F5-F10) provide high-current opendrain outputs on terminal blocks J4 & J5. Resistor packs RP8 & RP9 pull the Mosfets’ gates low to ensure that they’re off when not being driven by the port pins. An option is to configure PC2-PC7 as inputs. In this mode, the RP8 & RP9 positions are fitted with six zener diodes instead (not shown on circuit), providing over-voltage protection for the micro’s inputs. Also, two 3 x 4.7kW 6-pin resistor packs are installed in locations RP13 & RP14, and 5-way June 2005  89 Fig.3: the standard configuration for Port D uses three bits (PD4, PD5 & PD7) to drive power Mosfets and three bits (PD2, PD3 & PD6) as digital inputs. The lower two bits (PD0 & PD1) are used for an RS232 serial interface. socket strips are installed in locations RP2 & RP3. The socket strips accept 3 x 4.7kW 4-pin resistor packs, which can be used to pull up or pull down the inputs depending on how the packs are oriented in their sockets. Port D – RS232 serial port The ATmega32 hardware UART is a powerful device with receive buffers, 90  Silicon Chip its own baud rate generator, digital filters for noise reduction, multiple modes and three independent interrupts. The standard configuration for AVR200 serial communications is a minimum-component RS232 interface. This requires only two pins from port D: PD0 for “RXD” (receive data) and PD1 for “TXD” (transmit data). In this simple, no-handshake mode, links L20 & L21 are bridged, connecting PD0 & PD1 to the RS232 transceiver IC (U8). The other (line) side of the transceiver is connected to the RS232 D9 connector (J8) via link L13. Link L13 has two possible positions, allowing changeover of the TX and RX pins on the D9 connector to facilitate either DTE (Data Terminal Equipment) siliconchip.com.au or DCE (Data Communications Equipment) modes. For example, if talking to a modem, the AVR200 needs to appear as a DTE. Alternatively, if talking to a PC, the AVR200 should be linked as a DCE. If hardware handshaking is needed (using the RTS/CTS pair), then it can be incorporated by bridging link L22 and installing a jumper on L17 pins 2-3. This provides an RTS line driver and CTS receiver in U9, utilising port pins PD6 & PD7. L14 allows changeover of the RTS & CTS pins on the D9 connector to swap between DTE and DCE modes. Linking L14 pins 5 and 6 simply loops back RTS to CTS on the interface. Port D – RS485 or TTL serial ports (optional) The AVR200 also includes support for an RS485 communications port. In this case, links L20, L21 & L22 are left open and a multiplexer IC (U9) is installed, along with an RS485 transceiver (U10), two filters (LC2 & LC5) and a screw terminal block (J7). The multiplexer allows switching between the RS232 and RS485 serial interfaces, either manually via L19 or under program control via port pin PD4. By omitting the RS485 transceiver (but including the multiplexer) and installing a 4-pin strip header (J7B), it is possible to connect to TTL/CMOS compatible serial ports such as might be used on radios or GPS receivers, for example. Important: the RS485/TTL interface is optional and parts for it are not included in the standard kit, nor does it appear on the circuit diagram shown here. Information on these features is available from the JED website at www. jedmicro.com.au. Port D – digital inputs Port bits PD2, PD3 & PD6 are always digital inputs, normally accessible via screw terminal block J9. Alternatively, these inputs can be rerouted to perform other functions by moving links L15L17 from their normal positions (pins 1-2) to their secondary positions (pins 2-3). The alternate functions can be summarised as follows: • PD2 – interrupt (INT0) from the TWI bus (link L15); • PD3 – interrupt (INT1) from the TWI bus (link L16); • PD6 – CTS input from the RS232 port (link L17). Also, this port bit siliconchip.com.au can be pulled up (to +5V) or down to ground via link L18. Port D – digital I/O The standard configuration for port bits PD4, PD5 & PD7 are as outputs. Three MTD3055VL power Mosfets (F11-F13) provide high-current opendrain outputs on terminal block J10. A resistor pack (RP10) pulls the Mosfet gates low to ensure that they’re off when not being driven. Optionally, PD4, PD5 & PD7 may be configured as inputs. In this mode, the RP10 position is fitted with three zener diodes (not shown on the circuit) instead of the resistor pack to provide over-voltage protection. Also, a 3 x 4.7kW 6-pin resistor pack is installed in location RP16 and a 5-way socket strip is installed in location RP4. As described previously, the socket strip accepts a 3 x 4.7kW 4-pin resistor pack, which can be used to pull up or pull down the inputs. Note: PD7 is used as the RTS source if needed by the RS232 interface and as the TX-ON source in RS485 mode. PD4 is used as the multiplexer control bit if the optional programmable RS232/ RS485 interface is installed. Power supply DC power is applied to the board on terminal block J1. The rail is filtered with LC8, a combination ferrite inductor, capacitor and varistor. This removes much of the EMC entering or leaving the system via the power leads. An LM2940T-5 3-terminal voltage regulator provides on-board power conditioning. It’s a low-dropout design, which means that it can operate with DC inputs as low as 5.5V and still produce a regulated +5V output. Maximum continuous input is +18V, although it can withstand short transients to +60V and it includes reverse polarity protection. Separation of the analog and digital supply rails prior to the microcontroller inputs is effected with L1 & L2 and their associated 22mF and 100nF capacitors. This arrangement also prevents radiation of digital noise on the supply rails. That’s all we have space for this month. Next month, we’ll describe the assembly and give the various options available for programming the Atmega32 micro. We’ll also give the SC full pricing details for the kit. Fig.4: these diagrams show the various signal conditioning options for the port A 7-way socket strips. June 2005  91 PRODUCT SHOWCASE Hard disk drive “plays” through AV systems “New and innovative” said the press release (as do most). What can be new and innovative about a USB hard disk case? This one is! It’s not one of your runof-the-mill hard disks. Sure, it has the usual USB connectors and can store any file you can store on a “normal” hard disk – but it also sports audio and video out in both 2.5mm/RCA and S/ PDIF format – AND a remote control so you can sit back and enjoy it all! In a nutshell, the NOAX SSV HDD allows you total control over your music, videos and pictures. Anything you can store on hard disk, you can play – MPEG4/2/1, DIVx, XVID, DVD, VCD, SVCD, MP3, JPEG, etc. You record them on the hard disk in the normal way (eg, as downloads, ripped CD, copied disks or tapes, etc) but you can then plug the same disk into your home theatre system (or TV, or stereo amp) to play them back – with remote control! The on-screen display is intuitive and easy to follow, as is drive operation – it’s plug and play on modern systems appearing as a local drive, so you just drag and drop files. It’s priced at $199 PLUS the hard disk of your choice (20-80GB) – the bigger the hard disk, the more you can store. 80GB can store up to 80,000 hires photos, 20,000 music tracks, 500 hours of digital video or (of course!) 80GB of computer data. The NOAX SSV HDD comes with the AV cable, remote, USB, power adaptor and S/PDIF cable, as shown above. Contact: Skunkworks PO Box 1239 South Perth WA 6951 Tel: (08) 9313 4667 Fax: (08) 9313 4887 Website: www.skunkworks.com.au 92  Silicon Chip Five years ago, email in-boxes around the world were suddenly filled with emails containing the enticing subject “ILOVEYOU”. While some came from strange email addresses others came from trusted sources, family and friends. However, the one thing all the emails had in common was the attachment “LOVE-LETTER-FOR-YOU.TXT.VBS”. Likewise, the one thing that all the infected users shared was the curiosity and desire to click on that attachment. The result of the cleverly named attachment, combined with a lack of safe computing practices, proved to be very costly as I-Worm. Loveletter became one of the first mass mailing worm outbreaks. What has changed since the release of I-Worm.Loveletter ? The answer is very little. While the sophistication of some worms have gradually increased and the motive for virus writing has altered, virus authors today are still heavily relying on social engineering, that is naming their files creatively in an attempt to stimulate user curiosity and trick them into running their creations. Typically today, these filenames exploit high-profile celebrities (one of today’s most frequent being Paris Hilton) or hit movies and popular teen games (the population most likely to unknowingly execute a virus) or current world events. STEPDOWN TRANSFORMERS 60VA to 3KVA encased toroids Soft-sided enclosures Hammond Electronics has launched a new family of hand-held enclosures, the soft-sided 1553. Featuring an ergonometric curved shape that fits comfortably into the hand, the cases are initially available in two sizes, 117 x 79mm and 147 x 89mm, both produced in RAL 7035 light grey or RAL 9011 black. The units are moulded in general purpose ABS and are ideal for housing hand-held instruments, remote controllers, flying lead machine controllers and many other applications where a stylish, easy to hold enclosure is required. Both sizes are available with or without battery door and compartment and have a removable plastic front Five year anniversary of I-Worm.virus panel. The battery compartments are complete with four clips for use with two AA batteries and a flying lead connector for a 9V PP3 size. Contact: Hammond Electronics Pty Ltd GPO Box 812, Adelaide SA 5001 Tel: (08) 8235 9744 Fax: (08) 8356 3652 Website: www.hammondmfg.com Harbuch Electronics Pty Ltd 9/40 Leighton Pl. HORNSBY 2077 Ph (02) 9476-5854 Fx (02) 9476-3231 siliconchip.com.au Victoria University hosts Melbourne’s PICAXE fair On Saturday 30th April, the Computer Systems and Electronics Department of Victoria University hosted the Melbourne Picaxe Fair on behalf of MicroZed Computers. The day was a huge success with a large number of very keen electronics enthusiasts and electronics teachers attending and participants ranging in age from five to retired. Victoria University invited New Zealand Picaxe experts Stan Swan and Andrew Hornblow (shown at right in photo above) as guest presenters. Stan and Andrew conducted three workshop sessions during the day aimed at varying levels of ability. These workshops were well attended and enthusiastically received by participants. It was interesting hear from Andrew regarding the arrangements for the implementation of new electronics technologies in New Zealand secondary schools. It would appear that New Zealand industries have woken up, well before Australia, to the fact that there will be no young people suitably trained in electronics technologies in the future unless the technologies are introduced into secondary schools. To this end the New Zealand Industry Training Board has employed Andrew to write competency standards, develop suitable learning materials and provide secondary school teachers with professional development. In addition to this, Andrew moderates a secure on-line discussion forum for all secondary school students participating in electronics technologies in school programs. A number of Victorian secondary school teachers travelled from all parts of the state to attend the Melbourne Picaxe Fair as a professional development activity. These teachers are intending to implement the new and exciting Picaxe technology into secondary school curriculum. The Picaxe Fair included presentations from TAFE colleges, robot hobby groups and distributors, as well as the Victoria University staff. This provided participants with a wide array of interesting and exciting applications for Picaxe controllers of both an educational and industrial nature and the opportunity to purchase Picaxe boards and components direct from MicroZed Computers. Contact: MicroZed PO Box 634, Armidale NSW 2350 Tel: (02) 6772 2777 Fax: (02) 6772 8987 Website: www.microzed.com.au Online learning program helps cut OH&S training costs Businesses often find Occupational Health and Safety training costly and logistically difficult but a new online OH&S training courses developed by leading workers’ compensation insurer CGU will help businesses find it easier to meet their OH&S obligations and make their workplace safer. The online OH&S courses were developed by e3Learning. Training online means smaller businesses and those with people spread across different locations can comply with legal obligations to train staff and keep abreast of safety practices. There are many benefits to online learning, including flexibility and efficiency, as siliconchip.com.au well as time and cost savings – by up to 70%, compared to face-to-face. People in remote areas can also access the latest training in safety practices. One highlight of the courseware was the interactive format and simulated work environments. The web-based courses include: OH&S Induction and Fundamentals, Hazard Management for Supervisors, Incident Investigation, Hazardous Substances for Employers and Supervisors and Hazardous Substances (advanced). Access the courses at www.cgu.com. au/safety For more information, call CGU Safety and Risk Services on 1300 138 601 or http://cgusafety.e3learning.com.au/ SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE We specialise in providing a range of Low SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SCRadio WEBLINK SC WEBLINK SC WEBLINK Power solutions for OEM’s to incor- SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE porate in their wireless technology based SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC includes WEBLINK SC WEBLINK SC WE products. The innovative range SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE products from MK Consultants, the worldSC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE specialist manufacturer. SC WEBLINKrenowned SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC4934 WEBLINK SC WEBLINK SC WE Tel:(07) 4934 0413 Fax: (07) 0311 SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK WEBLINK WEBLINK SC a WEBLINK JEDSC designs andSC manufactures range ofSC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE singleSC board computers (basedSC onWEBLINK Wilke Tiger SC WEBLINK WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SCwell WEBLINK SCdisplays WEBLINK SC WEBLINK SC WE and Atmel AVR), as as LCD and SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE analog and digital I/O for PCs and controllers. SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE JED also makes a SC PCWEBLINK PROM programmer SC WEBLINK SC WEBLINK SC WEBLINKand SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE RS232/RS485 converters. SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE Tel: (03) 9762 3588 Fax: (03) 9762 5499 SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK WEBLINK SC WEBLINK WEBLINK OurSCwebsite is updated daily,SCwith over SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE 5,500 productsSCavailable through our SC WEBLINK SC WE SC WEBLINK SC WEBLINK WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE secure online ordering facility. SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE Features include data SC WEBLINK SC WE SC WEBLINK SC WEBLINK SCsemiconductor WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK sheets, media releases, software down- SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE loads, and much more. SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE Tel: 022 Tel: 1800 1800 022 888 888 SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE une SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WEBLINK SC WE TeleLink Communications WebLINK: telelink.com.au Jed Microprocessors Pty Ltd WebLINK: jedmicro.com.au JAYCAR JAYCAR ELECTRONICS ELECTRONICS WebLINK: WebLINK: www.jaycar.com.au www.jaycar.com.au J 2005  93 Aussie CoreChartFR graphical programming for US competition South Autralian-based eLabtronics’ CoreChartFR Graphical Assembler has been released to coincide with the US FIRST Robotics Competition grand final in Atlanta, involving 73,000 high school students in 19 countries. The FIRST Robotics Competition controllers can now be programmed with CoreChartFR’s graphical dragand-drop interface and drop-menu selections, reducing syntax errors significantly while maintaining machine level flexibility, code size and execution speed. The system encourages top-down programming with comments at every level. Each graphical icon generates an assembler instruction code. The C subroutines written for the FIRST Robotics controller can still be used. Programmers also have the option of including their own C subroutines. The CoreChartFR Subroutine Library Modules can be expanded by the user and exchanged with others. Students familiar with CoreChartFR can use CoreChart Professional to program a selection of 101 PIC microcontroller chips with a choice of 16 different PIC programmers. eLabtronics initiated the CoreChart based University High School Industry Robotic Peer Mentoring Program in South Australia. It aims to stimulate large scale science and mathematics learning in schools and to lead to innovative microchip skills development. CoreChartFR is available for trial at http://www.elabtronics.com/CoreChartFR.htm. It retails for $132.00 Contact: eLabtronics 51 Byron Place, Adelaide SA 5000 Tel: (08) 8231 5966 Fax (08) 8231 5266 Website: www.elabtronics.com 94  Silicon Chip New LED drop-in replacements for 12V halogens Prime Electronics have sent us some samples of their very new, very bright LED lamps which are a plug-in replacement for 12V halogen lamps (20W and 50W). They’re so new that we actually received the manufacturer’s samples; stocks are expected in Australia around the time this issue of SILICON CHIP goes to press. No pricing is available at this stage. One of the biggest advantages of LEDs is their dramatically longer life than the very-hot-running halogens. Most halogens are rated at 1000 hours (and often fail to meet that); these LED lamps have a 10,000 hour rating. Using a 3W LED, these lamps are available in four shades of white and 16 colours (and even a multi-colour 3-LED version which cycles through a colour-changing routine). They will operate from a 12-24V DC or a 12-18V AC supply, so existing halogen lamp transformers (including electronic versions) will not need replacing. Instead of the 20W or 50W required from the halogen transformer, the LED lamps are rated at just 5W so transformers will also run a lot cooler. With a 50mm diameter, they will fit into standard MR16 halogen light fittings – the two pins also fit standard connectors. Prime Electronics have showrooms in Brisbane, Sydney and on the Gold Coast. Contact: Prime Electronics 22-26 Campbell St, Bowen Hills Qld 4006 Tel: (07) 3252 7466 Fax: (07) 3252 2862 Website: www.prime-electronics.com.au Customisable microprocessor core modules Rabbit Semiconductors’ new PowerCore family of microprocessor core modules are designed to facilitate rapid development and implementation of embedded systems. Powered by high-performance 8-bit Rabbit microprocessors with extensive integrated features and a C-friendly instruction set designed for use with the Dynamic C development system, the PowerCore mounts on a user-designed motherboard (as shown at right) and acts as the controlling microprocessor for the user’s system. PowerCores with on-board power supplies can also provide power to the motherboard. Small in size but packed with powerful features, these core modules give designers a complete package for control and communication. With available on-board power supply, analog features, and the fastest Rabbit 3000 microprocessor, the PowerCore bridges the gap between microcontrollers and single board computers. Features such as microprocessor speed, power supply, memory, analog features and Ethernet capability can be customised via the Rabbit website using the online configuration tool. Rabbit are heralding this range as “the real alternative to off-the-shelf and custom manufacturing”. Created specifically to reduce the effort required to build embedded control applications, the PowerCore is available with 1MB Flash, 1MB SRAM and 1MB Serial Flash, as well as 5 serial ports, 39 I/O, real-time clock and Ethernet. On-board analog features include a ramp generator that, coupled with inexpensive comparators and the pulse capture capabilities of the Rabbit 3000 microprocessor, allows measurement of analog voltages for applications such as temperature sensing using the on-board thermistor. Contact: Dominion Electronics 18/32 Reserve Rd, Artarmon, NSW 2064 Tel: (02) 9906 6988 Fax (02) 9906 6988 Website: www.dominion.net.au siliconchip.com.au siliconchip.com.au June 2005  95 Vintage Radio By RODNEY CHAMPNESS, VK3UG Signal generators – what they are and how to fix them An RF signal generator is a vital when it comes to servicing and accurately aligning vintage radio receivers. However, it’s no good having a generator if it isn’t working correctly or isn’t calibrated. A RADIO FREQUENCY (RF) signal generator (or modulated oscillator) is an instrument that can act as a substitute for a radio station. It can be set to generate any frequency over its range and the resulting output signal level can also usually be varied before being fed to the radio under test. This allows several things to be checked and/or adjusted in the receiver, as follows: (1) the accuracy of the dial calibrations; (2) the receiver’s sensitivity, along with its ability to handle both weak and strong signals; (4) the amount of frequency drift in the local oscillator; and The Advance 62 signal generator is capable of generating frequencies from 150kHz to 300MHz over six ranges. It also features CW and tone modulation and is just the shot for aligning vintage radio receivers. 96  Silicon Chip (5) the receiver’s alignment, especially the IF (intermediate frequency) stages. In addition, a signal generator can feed a variable or fixed-level audio modulating signal into the RF oscillator for checking the performance of the audio section of the receiver. And of course, it can provide an audio signal for directly testing audio amplifier stages. Top of the range signal generators can also be used to perform a number of other tests on high-performance receivers. We’ll consider some of these tests later on. Typical units The term “signal generator” should really only apply to units that have a high order of frequency accuracy with rigidly controlled and calibrated output levels. In addition, it should be possible to control the output level down to a fraction of a microvolt at radio frequencies. One such unit is the Hewlett Packard 606B signal generator. As with similar units, its output level is accurately controlled and its frequency accuracy is set by either an in-built crystal-controlled marker oscillator or by an external source. In addition, its internal filtering and shielding is such that the only signal likely to be detected from the generator will be at the RF output terminal (and this will only be at a controlled level). On the other hand, “signal generators” like the Leader LSG10 and LSG11 should more correctly be called “modulated oscillators”. A modulated oscillator has little or no filtering or shielding to prevent an uncontrolled level of RF signal from “escaping” siliconchip.com.au Above: inside the Advance 62 signal generator with the RF shield in place. The view at right shows the unit with the shield removed (ie, by unscrewing it). from the unit. This signal may completely bypass the attenuator, which means that the output level is quite arbitrary. These and many similar older units are still useful for testing restored vintage radios, although they cannot be used for some precision tests. The output frequency from these modulated oscillators is usually accurately calibrated on the dial (making them useful for checking alignment and dial calibration, etc) but the output level cannot be relied upon. Before passing judgement on any of these instruments, it must be considered what work each was intended to do. For example, the Hewlett Packard 606B was designed for testing and aligning high-performance 2-way radios and was an expensive instrument when new. It was able to test many parameters other than RF sensitivity and frequency stability and an indication of its quality can be gauged by the fact it was used during the 1960s and 1970s by the Department of Communications (now ACA) in their Type Approval Laboratories. By contrast, signal generators such as the Leader LSG10 and LSG11 are much more modest but will still do a reasonable job for most vintage radio restorers. Between these two extremes are other instruments that will not only do the job for vintage radio restorers but will also meet the needs of radio amateurs. The latter typically require more accuracy than an LSG11 can give. Units such as the Advance P1 and 62 signal generators, for example, have quite good shielding and filtering to minimise signals escaping from siliconchip.com.au the case or being radiated down the power lead. Fixing an Advance P1 A friend who suffers from Parkinson’s disease is largely confined to a wheelchair and is unable to hold a soldering iron with a steady hand. He had been trying to restore the Advance P1 signal generator but due to his disability, was not making much progress. As a result, I agreed to do the job for him – he would get the unit back in working order and I could use the P1 as part of an article on test equipment. When he obtained the unit, it appeared as though it had been worked on by its previous owner, the power supply and audio oscillator section being the obvious “casualties” of this attention. My friend told me that the P1 came with a 5Y3GT rectifier for the power supply. However, this didn’t seem right to me as the power transformer was too small to provide enough power for even the 5Y3GT’s filament. Also, the valve socket was right alongside what I took to be the audio oscillator transformer. I traced the circuit out around the octal socket and found that it was connected to the audio transformer. Lacking a circuit, I had no way of knowing what valve had originally been used in the audio oscillator but experience told me that a 6J5 triode may suit. I looked up the pin-outs and found that it would indeed make a Hartley audio oscillator circuit if a 6J5 was plugged in. Having worked out what the octal socket and its adjacent circuitry did, it was time to look at the power supply. The 240V AC mains supply came in via a switch to the primary of a small transformer. I checked all the windings and found there was a tapped primary and two untapped secondary windings, one for the valve heaters and the other for the high tension (HT) supply. The mains was supplied by a 3-core lead and someone in the past had wired the Neutral (black wire) to the Active terminal of the plug. Due to this inaccurate wiring, the Active wire did not have the switch in series with it – 240V AC was applied to the power transformer whether the unit was switched on or off. This was corrected, so that the switch is now in the Active line. As part of the RF filtering, two 600V 1nF capacitors were wired between the Active and Earth and Neutral and Earth. However, 600V DC-rated capacitors are not at all suitable this job and may puncture due to voltage spikes on the mains. They were replaced with a purpose-made suppression block rated to work at 250V AC. Next, I removed the shield from the June 2005  97 The Leader LSG11 is a low-cost generator but is still useful for aligning vintage radio receivers. It produces frequencies ranging from 120kHz to 130MHz. the unearthed end of the “HT” winding was attached to an adjacent lug on the terminal strip. I fitted a 1N4004 diode between these two lugs and then tried the power supply again. A DC voltage of about 77V was the result, which seemed to me to be in the ballpark. I turned it off, refitted the 6J6 and the dial lamp, and then turned it on again. The generator warmed up and its signal could be heard in a portable receiver close by. I then decided to fit a 6J5 into the audio section and this also proved successful, with a tonemodulated signal now being heard in the receiver. This job turned out to be easier than I had expected, especially in view of the previous owner’s modifications. It was just luck that his “improvements” hadn’t caused damage to other sections of the circuit. With the unit now working, the next step was to spruce up the unit’s appearance. The cabinet was the obvious place to start, since its paint was in poor condition. It was sanded down and given several coats of matt black spray paint (although I suspect that the original cabinet colour was a hammertone grey). The front panel was more of a problem and I achieved only partial success by filling in the spots where the black paint was missing. However, some bare spots were too close to the lettering and I couldn’t afford to damage that. The accompanying photo shows the final result. It looks a lot better than before and it’s now a fully-functioing unit. Advance 62 signal generator This is the view inside the Leader LSG11 signal generator. Note the switched coils and the tuning capacitor. RF oscillator section and this revealed a 6J6 valve. This valve was removed, along with the dial lamp, and power applied to the unit. The filament voltage was up around 7.5V and the winding which I thought may have been for the HT produced just 55V AC. There was absolutely no way that a valve rectifier could have ever been 98  Silicon Chip fitted to this unit. Instead, a solid-state rectifier had obviously been fitted originally – perhaps a small selenium unit. Closer inspection showed that a wire went from a terminal strip located on the top of the transformer to an electrolytic capacitor in the power supply filter network. Furthermore, Another friend loaned me his Advance 62 signal generator (a later model) so that I could use it to work out what had been altered in the P1. I had expected them to use similar audio oscillators but found that there was a significant difference between the two circuits. The power supply sections are almost the same, though. Although I did work out most of the altered circuit section of the P1, the 62 provided a handy way to check whether my basic ideas were accurate or not. And the differences? – the P1 uses a 6J6 (both sections) as the RF oscillator and a 6J5 as the audio oscillator/modulator. By contrast, the 62 uses one half of a 12AT7 as the RF oscillator and the other half as the siliconchip.com.au audio oscillator/modulator. The P1 and the 62 are also quite different in the amount of filtering and shielding that they use. The P1 has a bolt-on cover over the oscillator which lets some signal leak out along the edges, while the 62 uses a large aluminium can with a screw type lid. This forms a cheap but very effective shield to prevent radiation. Filtering of the AC and DC leads is achieved using series RF chokes, feed-through capacitors and parallel polyester capacitors. The RF coils (chokes) are spread throughout both units on reddish-brown coil formers. The switched signal attenuator in the P1 uses several resistors within “view” of each other. This allows the VHF signals to partially bypass the attenuator. By contrast, the 62 has a much better shielded attenuator that isolates each section of the attenuator from the next. Both of these attenuators can be seen with their rear shields removed in the photographs. In operation, the P1 has a frequency range of 100kHz to 100MHz while the 62 covers 150kHz to 300MHz. That’s one reason for the better filtering and shielding in the 62; it has a much higher maximum frequency of operation. Both the P1 and the 62 proved to be quite stable in frequency when warming up. The case radiation from the P1 is quite noticeable, although nothing like the LSG11’s case radiation. The 62 is better still – on the broadcast band, its signal is barely audible on a sensitive AWA transistor portable placed one metre away. The Leader LSG11 The LSG11 is one of the cheaper devices but it still generates signals that can be used for aligning domestic vintage radios. Fig.1 shows the circuit details. The RF oscillator consists of one half of a 12BH7 (V2) which then feeds the second half of the valve. The audio oscillator is a 6AR5 in a Colpitts oscillator which also feeds into the grid of the second section of the 12BH7, where the audio and RF signals are mixed to give a modulated RF signal. The 6AR5 can also be used as a crystal oscillator which can be useful for aligning equipment on spot frequencies or for testing FT243 crystals. The RF range is from 120kHz to 130MHz, although harmonics can siliconchip.com.au Fig.1: the Leader LSG11 circuit uses just two valves. V1 (6AR5) functions as a Colpitts oscillator and this feeds the grid of one section of V2 (12BH7) where it is mixed with RF signals produced by the second section. extend this to 390MHz. However, the stability of the oscillator is insufficient to make it worthwhile using it on harmonics. The RF output level isn’t controlled in any way and it varies significantly across each band and between the various bands. An automatic gain control (AGC) system of some sort would maintain the output at a constant level but that would have added to the cost – and this is a cheap unit. It is different to the Advance units in that it can put out 400Hz or 1000Hz audio signals. The oscillator frequency stability June 2005  99 unit a lot more usable although it was still not of a high standard. As shown in the photos, the oscillator sections in the Advance units are more compact than in the LSG11. This means shorter lead lengths in the Advance units and they are also better shielded. Hewlett Packard 606B This is my friend’s Advance P1 signal generator before restoration. It proved easy to get going again, despite a previous owner’s strange “modifications”. and the frequency calibration of the dial are remarkably good for such a low-cost unit. However, signal radiation out of the case and across the attenuator is quite high. This makes comparative sensitivity checks on different receivers virtually impossible. That said, if you don’t want to spend much money and you can put up with the inadequacies of the LSG11 and its smaller brother the LSG10, they are well-worth having. A look inside the LSG11 reveals just how little filtering there is, which explains why its signal leakage levels are so high. Back in the 1970s, a couple of radio amateurs decided to “transistorise” their LSG11s. This reduced the level of radiation from the device, as there was no longer a power lead extending from the cabinet to carry RF signals (the modified units were fitted a small battery pack inside the cabinet). This modification made the This is the view inside the Advance P1 with its RF shield removed. Be sure to follow the existing lead dress when replacing parts in tuned circuits, otherwise the calibration will no longer be accurate. 100  Silicon Chip The 606B well and truly deserves to be called a signal generator. Indeed, this was the “Rolls Royce” of signal generators back in the 1960s. It is big (510 L x 350 D x 315mm H) and heavy, with a large handle at either end, and in its hey-day was very expensive. Today, they sell for as little as $50. That’s cheap but keep in mind that some of the parts are now hard to come by if something goes wrong. The 606B covers the RF range from 50kHz to 65MHz and the output signal level can be accurately set from a fraction of a microvolt to several volts. The modulation level is variable from 0-100% using either a 400Hz or 1kHz audio frequency from its internal audio oscillator or up to around 20kHz from an external source. One interesting feature is that its accuracy can be checked and adjusted using an internal crystal reference oscillator. Servicing a signal generator In many ways, a signal generator is much easier to service than a radio receiver. This particularly applies to the smaller, more modest units as the circuitry is usually fairly simple. A quick look at the circuit of the Leader LSG11 (Fig.1), for example, shows that there are only two valves and a modest number of passive components. Because signal generators are usually housed in a metal case, little dust gets inside to cause problems. And it’s easy to replace the valves or any other component – such as a capacitor or resistor – that’s not involved with the RF tuned circuit. Basically, a generator can be broken down into two sections: (1) the RF oscillator; and (2) the audio oscillator/ modulator. To check if the audio oscillator is working, just feed its output to an audio amplifier – a tone should be heard in the loudspeaker. You should be able to vary the level by adjusting the output level control. If nothing is heard, check the audio oscillator section for faults. siliconchip.com.au The RF section can be tested using a radio receiver. The first step is to tune the receiver to a vacant spot on the broadcast band. That done, you simply connect the generator’s output to the aerial and earth terminals and tune the generator across the broadcast band until a decrease in the background noise is observed. This occurs when the generator is set to the frequency tuned by the radio receiver. If the generator is now set for a modulated output, you should hear the tone from the receiver’s loudspeaker. If nothing is observed, check the circuit around the RF oscillator. As with the local oscillator in a receiver, a properly working stage will generate grid current. This can be checked by lifting the earth of the grid resistor (R11 in the case of the LSG11) and installing a multimeter (set to milliamps) in series between the resistor and earth. If the stage is working, you should get a reading of a few hundred microamps. If not check around this stage. If neither the audio or RF sections appear to be working, check that the heater and high tension (HT) voltages are present and are reaching all relevant parts of the circuit. It is quite OK to check the continuity of the RF coils (with the unit off) but do not try adjusting them as this will throw the calibration out. The LSG11 has no adjustments but the Advance units have adjustable iron dust cores in the coils and wire type trimmers across each coil. Unless you have a very accurate receiver or a frequency counter to check the tuning of the coils, leave them alone. When replacing parts around the tuned circuits, make sure they are dressed exactly the same way as the original parts as this can affect calibration. On the other hand, the layout is not quite so important in the audio and power sections. Finally, if there is any corrosion on the case or metal shields, carefully clean all mating surfaces to ensure that the shielding functions correctly. Summary With signal generators, it’s very much a case of “you get what you pay for”. The Leader LSG11 is a basic signal generator which will meet the requirements of most vintage radio restorers. It does have some inadequacies (such as variable output levels across each band) but for simple alignsiliconchip.com.au The Hewlett Packard 606B was considered to be the “Rolls Royce” of signal generators during the 1960s. Grab one of these if you can. ment work, it’s shortcomings aren’t really a problem. The Advance P1 and more so the Advance 62 provide better performance and will be appreciated by restorers who want to get the best out of multi-band receivers. If you can get one of these at a reasonable price, grab it. The Hewlett Packard 606B is the unit for those who want the best at a low price (secondhand, that is). I use mine almost exclusively for vintage SC radio work. Photo Gallery: Astor Aladdin Model FH Manufactured by Radio Corporation, Melbourne, in 1938, the Astor Aladdin FH was designed for use in areas without mains power. The set used 2V battery valves and was fitted with a vibrator power supply running from a 6V accumulator. A distinctive feature was its “Presto” tuning (with telephonestyle dial), which allowed for quick selection of preset stations. The valve line-up was as follows: IC7-G frequency changer; IF7-G first IF amplifier/ AVC rectifier; IF7-G second IF amplifier/audio amplifier/detector; and IF5-G audio output. Photo: Historical Radio Society of Australia, Inc. June 2005  101 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 Silicon Chip Back Issues April 1989: Auxiliary Brake Light Flasher; What You Need to Know About Capacitors; 32-Band Graphic Equaliser, Pt.2. May 1989: Build A Synthesised Tom-Tom; Biofeedback Monitor For Your PC; Simple Stub Filter For Suppressing TV Interference. July 1989: Exhaust Gas Monitor; Experimental Mains Hum Sniffers; Compact Ultrasonic Car Alarm; The NSW 86 Class Electrics. September 1989: 2-Chip Portable AM Stereo Radio Pt.1; High Or Low Fluid Level Detector; Studio Series 20-Band Stereo Equaliser, Pt.2. October 1989: FM Radio Intercom For Motorbikes Pt.1; GaAsFet Preamplifier For Amateur TV; 2-Chip Portable AM Stereo Radio, Pt.2. November 1989: Radfax Decoder For Your PC (Displays Fax, RTTY & Morse); FM Radio Intercom For Motorbikes, Pt.2; 2-Chip Portable AM Stereo Radio, Pt.3; Floppy Disk Drive Formats & Options. January 1990: High Quality Sine/Square Oscillator; Service Tips For Your VCR; Active Antenna Kit; Designing UHF Transmitter Stages. February 1990: A 16-Channel Mixing Desk; Build A High Quality Audio Oscillator, Pt.2; The Incredible Hot Canaries; Random Wire Antenna Tuner For 6 Metres; Phone Patch For Radio Amateurs, Pt.2. March 1990: Delay Unit For Automatic Antennas; Workout Timer For Aerobics Classes; 16-Channel Mixing Desk, Pt.2; Using The UC3906 SLA Battery Charger IC. April 1990: Dual Tracking ±50V Power Supply; Voice-Operated Switch With Delayed Audio; 16-Channel Mixing Desk, Pt.3; Active CW Filter. February 1993: Three Projects For Model Railroads; Low Fuel Indicator For Cars; Audio Level/VU Meter (LED Readout); An Electronic Cockroach; 2kW 24VDC To 240VAC Sinewave Inverter, Pt.5. March 1993: Solar Charger For 12V Batteries; Reaction Trainer; Audio Mixer for Camcorders; A 24-Hour Sidereal Clock For Astronomers. April 1993: Solar-Powered Electric Fence; Audio Power Meter; ThreeFunction Home Weather Station; 12VDC To 70VDC Converter. July 1993: Single Chip Message Recorder; Light Beam Relay Extender; AM Radio Trainer, Pt.2; Quiz Game Adjudicator; Antenna Tuners – Why They Are Useful. July 1995: Electric Fence Controller; How To Run Two Trains On A Single Track (Incl. Lights & Sound); Setting Up A Satellite TV Ground Station; Build A Reliable Door Minder. August 1993: Low-Cost Colour Video Fader; 60-LED Brake Light Array; Microprocessor-Based Sidereal Clock; Satellites & Their Orbits. August 1995: Fuel Injector Monitor For Cars; Gain Controlled Microphone Preamp; How To Identify IDE Hard Disk Drive Parameters. September 1993: Automatic Nicad Battery Charger/Discharger; Stereo Preamplifier With IR Remote Control, Pt.1; In-Circuit Transistor Tester; +5V to ±15V DC Converter; Remote-Controlled Cockroach. September 1995: Railpower Mk.2 Walkaround Throttle For Model Railways, Pt.1; Keypad Combination Lock; Jacob’s Ladder Display. October 1993: Courtesy Light Switch-Off Timer For Cars; Wireless Microphone For Musicians; Stereo Preamplifier With IR Remote Control, Pt.2; Electronic Engine Management, Pt.1. November 1993: High Efficiency Inverter For Fluorescent Tubes; Stereo Preamplifier With IR Remote Control, Pt.3; Siren Sound Generator; Engine Management, Pt.2; Experiments For Games Cards. July 1990: Digital Sine/Square Generator, Pt.1 (0-500kHz); Burglar Alarm Keypad & Combination Lock; Build A Simple Electronic Die; January 1994: 3A 40V Variable Power Supply; Solar Panel Switching Regulator; Printer Status Indicator; Mini Drill Speed Controller; Stepper Motor Controller; Active Filter Design; Engine Management, Pt.4. October 1990: The Dangers of PCBs; Low-Cost Siren For Burglar Alarms; Dimming Controls For The Discolight; Surfsound Simulator; DC Offset For DMMs; NE602 Converter Circuits. November 1990: Connecting Two TV Sets To One VCR; Build An Egg Timer; Low-Cost Model Train Controller; 1.5V To 9V DC Converter; Introduction To Digital Electronics; A 6-Metre Amateur Transmitter. January 1991: Fast Charger For Nicad Batteries, Pt.1; Have Fun With The Fruit Machine (Simple Poker Machine); Two-Tone Alarm Module; The Dangers of Servicing Microwave Ovens. February 1991: A Practical Approach To Amplifier Design; Synthesised Stereo AM Tuner; Three Inverters For Fluorescent Lights; Low-Cost Sinewave Oscillator; Fast Charger For Nicad Batteries, Pt.2. May 1991: 13.5V 25A Power Supply For Transceivers; Stereo Audio Expander; Fluorescent Light Simulator For Model Railways; How To Install Multiple TV Outlets, Pt.1. July 1991: Loudspeaker Protector For Stereo Amplifiers; 4-Channel Lighting Desk, Pt.2; How To Install Multiple TV Outlets, Pt.2; Tuning In To Satellite TV, Pt.2. February 1994:90-Second Message Recorder; 12-240VAC 200W Inverter; 0.5W Audio Amplifier; 3A 40V Adjustable Power Supply; Engine Management, Pt.5; Airbags In Cars – How They Work. March 1994: Intelligent IR Remote Controller; 50W (LM3876) Audio Amplifier Module; Level Crossing Detector For Model Railways; Voice Activated Switch For FM Microphones; Engine Management, Pt.6. April 1994: Sound & Lights For Model Railway Level Crossings; Dual Supply Voltage Regulator; Universal Stereo Preamplifier; Digital Water Tank Gauge; Engine Management, Pt.7. May 1994: Fast Charger For Nicad Batteries; Induction Balance Metal Locator; Multi-Channel Infrared Remote Control; Dual Electronic Dice; Simple Servo Driver Circuits; Engine Management, Pt.8. June 1994: A Coolant Level Alarm For Your Car; 80-Metre AM/CW Transmitter For Amateurs; Converting Phono Inputs To Line Inputs; PC-Based Nicad Battery Monitor; Engine Management, Pt.9. August 1994: High-Power Dimmer For Incandescent Lights; Dual Diversity Tuner For FM Microphones, Pt.1; Nicad Zapper (For Resurrecting Nicad Batteries); Electronic Engine Management, Pt.11. October 1991: A Talking Voltmeter For Your PC, Pt.1; SteamSound Simulator For Model Railways Mk.II; Magnetic Field Strength Meter; Digital Altimeter For Gliders, Pt.2; Military Applications Of R/C Aircraft. October 1994: How Dolby Surround Sound Works; Dual Rail Variable Power Supply; Talking Headlight Reminder; Electronic Ballast For Fluorescent Lights; Electronic Engine Management, Pt.13. December 1991: TV Transmitter For VCRs With UHF Modulators; IR Light Beam Relay; Colour TV Pattern Generator, Pt.2; Index To Vol.4. November 1994: Dry Cell Battery Rejuvenator; Novel Alphanumeric Clock; 80-M DSB Amateur Transmitter; 2-Cell Nicad Discharger. April 1992: IR Remote Control For Model Railroads; Differential Input Buffer For CROs; Aligning Vintage Radio Receivers, Pt.1. December 1994: Car Burglar Alarm; Three-Spot Low Distortion Sinewave Oscillator; Clifford – A Pesky Electronic Cricket; Remote Control System for Models, Pt.1; Index to Vol.7. ORDER FORM November 1995: Mixture Display For Fuel Injected Cars; CB Trans­verter For The 80M Amateur Band, Pt.1; PIR Movement Detector. December 1995: Engine Immobiliser; 5-Band Equaliser; CB Transverter For The 80M Amateur Band, Pt.2; Subwoofer Controller; Knock Sensing In Cars; Index To Volume 8. June 1996: Stereo Simulator (uses delay chip); Rope Light Chaser; Low Ohms Tester For Your DMM; Automatic 10A Battery Charger. July 1996: VGA Digital Oscilloscope, Pt.1; Remote Control Extender For VCRs; 2A SLA Battery Charger; 3-Band Parametric Equaliser;. August 1996: Introduction to IGBTs; Electronic Starter For Fluores­cent Lamps; VGA Oscilloscope, Pt.2; 350W Amplifier Module; Masthead Amplifier For TV & FM; Cathode Ray Oscilloscopes, Pt.4. September 1996: VGA Oscilloscope, Pt.3; IR Stereo Headphone Link, Pt.1; High Quality PA Loudspeaker; 3-Band HF Amateur Radio Receiver; Cathode Ray Oscilloscopes, Pt.5. October 1996: Send Video Signals Over Twisted Pair Cable; 600W DC-DC Converter For Car Hifi Systems, Pt.1; IR Stereo Headphone Link, Pt.2; Multi-Channel Radio Control Transmitter, Pt.8. November 1996: 8-Channel Stereo Mixer, Pt.1; Low-Cost Fluorescent Light Inverter; Repairing Domestic Light Dimmers; 600W DC-DC Converter For Car Hifi Systems, Pt.2. December 1996: Active Filter For CW Reception; Fast Clock For Railway Modellers; Laser Pistol & Electronic Target; Build A Sound Level Meter; 8-Channel Stereo Mixer, Pt.2; Index To Vol.9. July 1994: Build A 4-Bay Bow-Tie UHF TV Antenna; PreChamp 2-Transistor Preamplifier; Steam Train Whistle & Diesel Horn Simulator; 6V SLA Battery Charger; Electronic Engine Management, Pt.10. September 1994: Automatic Discharger For Nicad Batteries; MiniVox Voice Operated Relay; AM Radio For Weather Beacons; Dual Diversity Tuner For FM Mics, Pt.2; Electronic Engine Management, Pt.12. October 1992: 2kW 24VDC - 240VAC Sinewave Inverter; Multi-Sector Home Burglar Alarm, Pt.2; Mini Amplifier For Personal Stereos; A Regulated Lead-Acid Battery Charger. October 1995: 3-Way Loudspeaker System; Railpower Mk.2 Walkaround Throttle For Model Railways, Pt.2; Nicad Fast Charger. May 1996: High Voltage Insulation Tester; Knightrider LED Chaser; Simple Intercom Uses Optical Cable; Cathode Ray Oscilloscopes, Pt.3. September 1991: Digital Altimeter For Gliders & Ultralights; Ultrasonic Switch For Mains Appliances; The Basics Of A/D & D/A Conversion. June 1992: Multi-Station Headset Intercom, Pt.1; Video Switcher For Camcorders & VCRs; IR Remote Control For Model Railroads, Pt.3; 15-Watt 12-240V Inverter; A Look At Hard Disk Drives. May 1995: Guitar Headphone Amplifier; FM Radio Trainer, Pt.2; Transistor/Mosfet Tester For DMMs; A 16-Channel Decoder For Radio Remote Control; Introduction To Satellite TV. June 1995: Build A Satellite TV Receiver; Train Detector For Model Railways; 1W Audio Amplifier Trainer; Low-Cost Video Security System; Multi-Channel Radio Control Transmitter For Models, Pt.1. December 1993: Remote Controller For Garage Doors; LED Stroboscope; 25W Audio Amplifier Module; A 1-Chip Melody Generator; Engine Management, Pt.3; Index To Volume 6. September 1990: 3-Digit Counter Module; Simple Shortwave Converter For The 2-Metre Band; Taking Care Of Nicad Battery Packs. April 1995: FM Radio Trainer, Pt.1; Balanced Mic Preamp & Line Filter; 50W/Channel Stereo Amplifier, Pt.2; Wide Range Electrostatic Loudspeakers, Pt.3; 8-Channel Decoder For Radio Remote Control. June 1993: AM Radio Trainer, Pt.1; Remote Control For The Woofer Stopper; Digital Voltmeter For Cars. June 1990: Multi-Sector Home Burglar Alarm; Build A Low-Noise Universal Stereo Preamplifier; Load Protector For Power Supplies. August 1990: Universal Safety Timer For Mains Appliances (9 Minutes); Horace The Electronic Cricket; Digital Sine/Square Generator, Pt.2. March 1995: 2 x 50W Stereo Amplifier, Pt.1; Subcarrier Decoder For FM Receivers; Wide Range Electrostatic Loudspeakers, Pt.2; IR Illuminator For CCD Cameras; Remote Control System For Models, Pt.3. January 1997: How To Network Your PC; Control Panel For Multiple Smoke Alarms, Pt.1; Build A Pink Noise Source; Computer Controlled Dual Power Supply, Pt.1; Digi-Temp Thermometer (Monitors Eight Temperatures). February 1997: PC-Con­trolled Moving Message Display; Computer Controlled Dual Power Supply, Pt.2; Alert-A-Phone Loud Sounding Telephone Alarm; Control Panel For Multiple Smoke Alarms, Pt.2. March 1997: 175W PA Amplifier; Signalling & Lighting For Model Railways; Jumbo LED Clock; Cathode Ray Oscilloscopes, Pt.7. April 1997: Simple Timer With No ICs; Digital Voltmeter For Cars; Loudspeaker Protector For Stereo Amplifiers; Model Train Controller; A Look At Signal Tracing; Pt.1; Cathode Ray Oscilloscopes, Pt.8. May 1997: Neon Tube Modulator For Light Systems; Traffic Lights For A Model Intersection; The Spacewriter – It Writes Messages In Thin Air; A Look At Signal Tracing; Pt.2; Cathode Ray Oscilloscopes, Pt.9. January 1995: Sun Tracker For Solar Panels; Battery Saver For Torches; Dual Channel UHF Remote Control; Stereo Microphone Pre­amp­lifier. June 1997: PC-Controlled Thermometer/Thermostat; TV Pattern Generator, Pt.1; Audio/RF Signal Tracer; High-Current Speed Controller For 12V/24V Motors; Manual Control Circuit For Stepper Motors. February 1995: 2 x 50W Stereo Amplifier Module; Digital Effects Unit For Musicians; 6-Channel LCD Thermometer; Wide Range Electrostatic Loudspeakers, Pt.1; Remote Control System For Models, Pt.2. July 1997: Infrared Remote Volume Control; A Flexible Interface Card For PCs; Points Controller For Model Railways; Colour TV Pattern Generator, Pt.2; An In-Line Mixer For Radio Control Receivers. Please send the following back issues:________________________________________ Enclosed is my cheque/money order for $­______or please debit my:  Bankcard  Visa Card  Master Card Card No. Signature ___________________________ Card expiry date_____ /______ Name ______________________________ Phone No (___) ____________ PLEASE PRINT Street ______________________________________________________ Suburb/town _______________________________ Postcode ___________ 104  Silicon Chip 10% OF SUBSCR F TO IB OR IF Y ERS OU BUY 10 OR M ORE Note: prices include postage & packing Australia ............................... $A8.80 (incl. GST) Overseas (airmail) ..................................... $A10 Detach and mail to: Silicon Chip Publications, PO Box 139, Collaroy, NSW, Australia 2097. Or call (02) 9979 5644 & quote your credit card details or fax the details to (02) 9979 6503. Email: silchip<at>siliconchip.com.au siliconchip.com.au October 1997: 5-Digit Tachometer; Central Locking For Your Car; PCControlled 6-Channel Voltmeter; 500W Audio Power Amplifier, Pt.3. October 2000: Guitar Jammer; Breath Tester; Wand-Mounted Inspection Camera; Subwoofer For Cars; Fuel Mixture Display, Pt.2. November 1997: Heavy Duty 10A 240VAC Motor Speed Controller; Easy-To-Use Cable & Wiring Tester; Build A Musical Doorbell; Replacing Foam Speaker Surrounds; Understanding Electric Lighting Pt.1. November 2000: Santa & Rudolf Chrissie Display; 2-Channel Guitar Preamplifier, Pt.1; Message Bank & Missed Call Alert; Protoboards – The Easy Way Into Electronics, Pt.3. December 1997: Speed Alarm For Cars; 2-Axis Robot With Gripper; Stepper Motor Driver With Onboard Buffer; Power Supply For Stepper Motor Cards; Understanding Electric Lighting Pt.2; Index To Vol.10. December 2000: Home Networking For Shared Internet Access; White LED Torch; 2-Channel Guitar Preamplifier, Pt.2 (Digital Reverb); Driving An LCD From The Parallel Port; Index To Vol.13. January 1998: 4-Channel 12VDC or 12VAC Lightshow, Pt.1; Command Control For Model Railways, Pt.1; Pan Controller For CCD Cameras. January 2001: How To Transfer LPs & Tapes To CD; The LP Doctor – Clean Up Clicks & Pops, Pt.1; Arbitrary Waveform Generator; 2-Channel Guitar Preamplifier, Pt.3; PIC Programmer & TestBed. February 1998: Multi-Purpose Fast Battery Charger, Pt.1; Telephone Exchange Simulator For Testing; Command Control System For Model Railways, Pt.2; Build Your Own 4-Channel Lightshow, Pt.2. April 1998: Automatic Garage Door Opener, Pt.1; 40V 8A Adjustable Power Supply, Pt.1; PC-Controlled 0-30kHz Sinewave Generator; Understanding Electric Lighting; Pt.6. May 1998: 3-LED Logic Probe; Garage Door Opener, Pt.2; Command Control System, Pt.4; 40V 8A Adjustable Power Supply, Pt.2. June 1998: Troubleshooting Your PC, Pt.2; Universal High Energy Ignition System; The Roadies’ Friend Cable Tester; Universal Stepper Motor Controller; Command Control For Model Railways, Pt.5. July 1998: Troubleshooting Your PC, Pt.3; 15W/Ch Class-A Audio Amplifier, Pt.1; Simple Charger For 6V & 12V SLA Batteries; Auto­ matic Semiconductor Analyser; Understanding Electric Lighting, Pt.8. August 1998: Troubleshooting Your PC, Pt.4; I/O Card With Data Logging; Beat Triggered Strobe; 15W/Ch Class-A Stereo Amplifier, Pt.2. September 1998: Troubleshooting Your PC, Pt.5; A Blocked Air-Filter Alarm; Waa-Waa Pedal For Guitars; Jacob’s Ladder; Gear Change Indicator For Cars; Capacity Indicator For Rechargeable Batteries. October 1998: AC Millivoltmeter, Pt.1; PC-Controlled Stress-O-Meter; Versatile Electronic Guitar Limiter; 12V Trickle Charger For Float Conditions; Adding An External Battery Pack To Your Flashgun. November 1998: The Christmas Star; A Turbo Timer For Cars; Build A Poker Machine, Pt.1; FM Transmitter For Musicians; Lab Quality AC Millivoltmeter, Pt.2; Improving AM Radio Reception, Pt.1. December 1998: Engine Immobiliser Mk.2; Thermocouple Adaptor For DMMs; Regulated 12V DC Plugpack; Build A Poker Machine, Pt.2; Improving AM Radio Reception, Pt.2; Mixer Module For F3B Gliders. February 2001: An Easy Way To Make PC Boards; L’il Pulser Train Controller; A MIDI Interface For PCs; Build The Bass Blazer; 2-Metre Groundplane Antenna; LP Doctor – Clean Up Clicks & Pops, Pt.2. March 2001: Making Photo Resist PC Boards; Big-Digit 12/24 Hour Clock; Parallel Port PIC Programmer & Checkerboard; Protoboards – The Easy Way Into Electronics, Pt.5; A Simple MIDI Expansion Box. April 2001: A GPS Module For Your PC; Dr Video – An Easy-To-Build Video Stabiliser; Tremolo Unit For Musicians; Minimitter FM Stereo Transmitter; Intelligent Nicad Battery Charger. May 2001: 12V Mini Stereo Amplifier; Two White-LED Torches To Build; PowerPak – A Multi-Voltage Power Supply; Using Linux To Share An Internet Connection, Pt.1; Tweaking Windows With TweakUI. May 2003: Widgybox Guitar Distortion Effects Unit; 10MHz Direct Digital Synthesis Generator; Big Blaster Subwoofer; Printer Port Simulator; PICAXE, Pt.4 (Motor Controller). June 2003: PICAXE, Pt.5; PICAXE-Controlled Telephone Intercom; PICAXE-08 Port Expansion; Sunset Switch For Security & Garden Lighting; Digital Reaction Timer; Adjustable DC-DC Converter For Cars; Long-Range 4-Channel UHF Remote Control. July 2003: Smart Card Reader & Programmer; Power-Up Auto Mains Switch; A “Smart” Slave Flash Trigger; Programmable Continuity Tester; PICAXE Pt.6 – Data Communications; Updating The PIC Programmer & Checkerboard; RFID Tags – How They Work. August 2003: PC Infrared Remote Receiver (Play DVDs & MP3s On Your PC Via Remote Control); Digital Instrument Display For Cars, Pt.1; Home-Brew Weatherproof 2.4GHz WiFi Antennas; PICAXE Pt.7. September 2003: Robot Wars; Krypton Bike Light; PIC Programmer; Current Clamp Meter Adapter For DMMs; PICAXE Pt.8 – A Data Logger; Digital Instrument Display For Cars, Pt.2. October 2003: PC Board Design, Pt.1; JV80 Loudspeaker System; A Dirt Cheap, High-Current Power Supply; Low-Cost 50MHz Frequency Meter; Long-Range 16-Channel Remote Control System. November 2003: PC Board Design, Pt.2; 12AX7 Valve Audio Preamplifier; Our Best Ever LED Torch; Smart Radio Modem For Microcontrollers; PICAXE Pt.9; Programmable PIC-Powered Timer. June 2001: Universal Battery Charger, Pt.1; Phonome – Call, Listen In & Switch Devices On & Off; Low-Cost Automatic Camera Switcher; Using Linux To Share An Internet Connection, Pt.2; A PC To Die For, Pt.1. December 2003: How To Receive Weather Satellite Images; SelfDiagnostics Plug For Cars; PC Board Design, Pt.3; VHF Receiver For Weather Satellites; Linear Supply For Luxeon 1W Star LEDs; 5V Meter Calibration Standard; PIC-Based Car Battery Monitor; PICAXE Pt.10. July 2001: The HeartMate Heart Rate Monitor; Do Not Disturb Tele­phone Timer; Pic-Toc – A Simple Alarm Clock; Fast Universal Battery Charger, Pt.2; A PC To Die For, Pt.2; Backing Up Your Email. January 2004: Studio 350W Power Amplifier Module, Pt.1; HighEfficiency Power Supply For 1W Star LEDs; Antenna & RF Preamp For Weather Satellites; Lapel Microphone Adaptor For PA Systems; PICAXE-18X 4-Channel Datalogger, Pt.1; 2.4GHZ Audio/Video Link. August 2001: DI Box For Musicians; 200W Mosfet Amplifier Module; Headlight Reminder; 40MHz 6-Digit Frequency Counter Module; A PC To Die For, Pt.3; Using Linux To Share An Internet Connection, Pt.3. September 2001: Making MP3s; Build An MP3 Jukebox, Pt.1; PCControlled Mains Switch; Personal Noise Source For Tinnitus; Directional Microphone; Using Linux To Share An Internet Connection, Pt.4. November 2001: Ultra-LD 100W/Channel Stereo Amplifier, Pt.1; Neon Tube Modulator For Cars; Audio/Video Distribution Amplifier; Build A Short Message Recorder Player; Useful Tips For Your PC. February 2004: PC Board Design For Beginners, Pt.1; Simple Supply Rail Monitor For PCs; Studio 350W Power Amplifier Module, Pt.2; Fantastic Human-Powered LED Torches; Shorted Turns Tester For Line Output Transformers; PICAXE-18X 4-Channel Datalogger, Pt.2. March 2004: PC Board Design For Beginners, Pt.2; Build The QuickBrake For Increased Driving Safety; 3V-9V (or more) DC-DC Converter; ESR Meter Mk.2, Pt.1; PICAXE-18X 4-Channel Datalogger, Pt.3. December 2001: IR Transceiver For PCs; 100W/Ch Stereo Amplifier, Pt.2; Pardy Lights Colour Display; PIC Fun – Learning About Micros. April 2004: PC Board Design For Beginners, Pt.3; Loudspeaker Level Meter For Home Theatre Systems; Shut That Mutt (Electronic Dog Silencer); Smart Mixture Display For Cars; ESR Meter Mk.2, Pt.2; PC/ PICAXE Interface For UHF Remote Control. March 1999: Build A Digital Anemometer; DIY PIC Programmer; Build An Audio Compressor; Low-Distortion Audio Signal Generator, Pt.2. January 2002: Touch And/Or Remote-Controlled Light Dimmer, Pt.1; A Cheap ’n’Easy Motorbike Alarm; 100W /Channel Stereo Amplifier, Pt.3; Build A Raucous Alarm; FAQs On The MP3 Jukebox. May 2004: Amplifier Testing Without High-Tech Gear; Component Video To RGB Converter; Starpower Switching Supply For Luxeon Star LEDs; Wireless Parallel Port; Poor Man’s Metal Locator. April 1999: Getting Started With Linux; Pt.2; High-Power Electric Fence Controller; Bass Cube Subwoofer; Programmable Thermostat/ Thermometer; Build An Infrared Sentry; Rev Limiter For Cars. February 2002: 10-Channel IR Remote Control Receiver; 2.4GHz High-Power Audio-Video Link; Touch And/Or Remote-Controlled Light Dimmer, Pt.2; Booting A PC Without A Keyboard; 4-Way Event Timer. June 2004: Dr Video Mk.2 Video Stabiliser; Build An RFID Security Module; Fridge-Door Alarm; Courtesy Light Delay For Cars; Automating PC Power-Up; Upgraded Software For The EPROM Programmer. May 1999: The Line Dancer Robot; An X-Y Table With Stepper Motor Control, Pt.1; Three Electric Fence Testers; Carbon Monoxide Alarm. March 2002: Mighty Midget Audio Amplifier Module; 6-Channel IR Remote Volume Control, Pt.1; RIAA Pre­-­Amplifier For Magnetic Cartridges; 12/24V Intelligent Solar Power Battery Charger. July 2004: Silencing A Noisy PC; Versatile Battery Protector; Appliance Energy Meter, Pt.1; A Poor Man’s Q Meter; Regulated High-Voltage Supply For Valve Amplifiers; Remote Control For A Model Train Layout. April 2002:Automatic Single-Channel Light Dimmer; Pt.1; Water Level Indicator; Multiple-Output Bench Power Supply; Versatile Multi-Mode Timer; 6-Channel IR Remote Volume Control, Pt.2. August 2004: Video Formats: Why Bother?; VAF’s New DC-X Generation IV Loudspeakers; Video Enhancer & Y/C Separator; Balanced Microphone Preamp; Appliance Energy Meter, Pt.2; 3-State Logic Probe. May 2002: 32-LED Knightrider; The Battery Guardian (Cuts Power When the Battery Voltage Drops); Stereo Headphone Amplifier; Automatic Single-Channel Light Dimmer; Pt.2; Stepper Motor Controller. September 2004: Voice Over IP (VoIP) For Beginners; WiFry – Cooking Up 2.4GHz Antennas; Bed Wetting Alert; Build a Programmable Robot; Another CFL Inverter. June 2002: Lock Out The Bad Guys with A Firewall; Remote Volume Control For Stereo Amplifiers; The “Matchless” Metal Locator; Compact 0-80A Automotive Ammeter; Constant High-Current Source. October 2004: The Humble “Trannie” Turns 50; SMS Controller, Pt.1; RGB To Component Video Converter; USB Power Injector; Remote Controller For Garage Doors & Gates. July 2002: Telephone Headset Adaptor; Rolling Code 4-Channel UHF Remote Control; Remote Volume Control For The Ultra-LD Stereo Amplifier; Direct Conversion Receiver For Radio Amateurs, Pt.1. November 2004: 42V Car Electrical Systems; USB-Controlled Power Switch (Errata Dec. 2004); Charger For Deep-Cycle 12V Batteries, Pt.1; Driveway Sentry; SMS Controller, Pt.2; PICAXE IR Remote Control. August 2002: Digital Instrumentation Software For PCs; Digital Storage Logic Probe; Digital Therm./Thermostat; Sound Card Interface For PC Test Instruments; Direct Conversion Receiver For Radio Amateurs. December 2004: Build A Windmill Generator, Pt.1; 20W Amplifier Module; Charger For Deep-Cycle 12V Batteries, Pt.2; Solar-Powered Wireless Weather Station; Bidirectional Motor Speed Controller. September 2002: 12V Fluorescent Lamp Inverter; 8-Channel Infrared Remote Control; 50-Watt DC Electronic Load; Spyware – An Update. January 2005: Windmill Generator, Pt.2; Build A V8 Doorbell; IR Remote Control Checker; 4-Minute Shower Timer; The Prawnlite; Sinom Says Game; VAF DC-7 Generation 4 Kit Speakers. January 1999: High-Voltage Megohm Tester; A Look At The BASIC Stamp; Bargraph Ammeter For Cars; Keypad Engine Immobiliser. June 1999: FM Radio Tuner Card For PCs; X-Y Table With Stepper Motor Control, Pt.2; Programmable Ignition Timing Module For Cars, Pt.1. July 1999: Build A Dog Silencer; 10µH to 19.99mH Inductance Meter; Audio-Video Transmitter; Programmable Ignition Timing Module For Cars, Pt.2; XYZ Table With Stepper Motor Control, Pt.3. August 1999: Remote Modem Controller; Daytime Running Lights For Cars; Build A PC Monitor Checker; Switching Temperature Controller; XYZ Table With Stepper Motor Control, Pt.4; Electric Lighting, Pt.14. September 1999: Autonomouse The Robot, Pt.1; Voice Direct Speech Recognition Module; Digital Electrolytic Capacitance Meter; XYZ Table With Stepper Motor Control, Pt.5; Peltier-Powered Can Cooler. October 1999: Build The Railpower Model Train Controller, Pt.1; Semiconductor Curve Tracer; Autonomouse The Robot, Pt.2; XYZ Table With Stepper Motor Control, Pt.6; Introducing Home Theatre. November 1999: Setting Up An Email Server; Speed Alarm For Cars, Pt.1; LED Christmas Tree; Intercom Station Expander; Foldback Loudspeaker System; Railpower Model Train Controller, Pt.2. December 1999: Solar Panel Regulator; PC Powerhouse (gives +12V, +9V, +6V & +5V rails); Fortune Finder Metal Locator; Speed Alarm For Cars, Pt.2; Railpower Model Train Controller, Pt.3; Index To Vol.12. January 2000: Spring Reverberation Module; An Audio-Video Test Generator; Parallel Port Interface Card; Telephone Off-Hook Indicator. February 2000: Multi-Sector Sprinkler Controller; A Digital Voltmeter For Your Car; Safety Switch Checker; Sine/Square Wave Oscillator. March 2000: Resurrecting An Old Computer; 100W Amplifier Module, Pt.1; Electronic Wind Vane With 16-LED Display; Glowplug Driver. May 2000: Ultra-LD Stereo Amplifier, Pt.2; LED Dice (With PIC Microcontroller); 50A Motor Speed Controller For Models. June 2000: Automatic Rain Gauge; Parallel Port VHF FM Receiver; Switchmode Power Supply (1.23V to 40V) Pt.1; CD Compressor. July 2000: Moving Message Display; Compact Fluorescent Lamp Driver; Musicians’ Lead Tester; Switchmode Power Supply, Pt.2. October 2002: Speed Controller For Universal Motors; PC Parallel Port Wizard; Cable Tracer; AVR ISP Serial Programmer; 3D TV. November 2002: SuperCharger For NiCd/NiMH Batteries, Pt.1; Windows-Based EPROM Programmer, Pt.1; 4-Digit Crystal-Controlled Timing Module; Using Linux To Share An Optus Cable Modem, Pt.1. December 2002: Receiving TV From Satellites; Pt.1; The Micromitter Stereo FM Transmitter; Windows-Based EPROM Programmer, Pt.2; SuperCharger For NiCd/NiMH Batteries; Pt.2; Simple VHF FM/AM Radio; Using Linux To Share An Optus Cable Modem, Pt.2. January 2003: Receiving TV From Satellites, Pt 2; SC480 50W RMS Amplifier Module, Pt.1; Gear Indicator For Cars; Active 3-Way Crossover For Speakers; Using Linux To Share An Optus Cable Modem, Pt.3. February 2003: PortaPal PA System, Pt.1; SC480 50W RMS Amplifier Module, Pt.2; Windows-Based EPROM Programmer, Pt.3; Using Linux To Share An Optus Cable Modem, Pt.4; Fun With The PICAXE, Pt.1. August 2000: Theremin; Spinner (writes messages in “thin-air”); Proximity Switch; Structured Cabling For Computer Networks. March 2003: LED Lighting For Your Car; Peltier-Effect Tinnie Cooler; PortaPal PA System, Pt.2; 12V SLA Battery Float Charger; Little Dynamite Subwoofer; Fun With The PICAXE, Pt.2 (Shop Door Minder). September 2000: Swimming Pool Alarm; 8-Channel PC Relay Board; Fuel Mixture Display For Cars, Pt.1; Protoboards – The Easy Way Into Electronics, Pt.1; Cybug The Solar Fly. April 2003: Video-Audio Booster For Home Theatre Systems; Telephone Dialler For Burglar Alarms; Three PIC Programmer Kits; PICAXE, Pt.3 (Heartbeat Simulator); Electric Shutter Release For Cameras. siliconchip.com.au February 2005: Windmill Generator, Pt.3; USB-Controlled Electrocardiograph; TwinTen Stereo Amplifier; Inductance & Q-Factor Meter, Pt.1; A Yagi Antenna For UHF CB; $2 Battery Charger. March 2005: Windmill Generator, Pt.4; Sports Scoreboard, Pt.1; Swimming Pool Lap Counter; Inductance & Q-Factor Meter, Pt.2; Shielded Loop Antenna For AM; Cheap UV EPROM Eraser; Sending Picaxe Data Over 477MHz UHF CB; $10 Lathe & Drill Press Tachometer. April 2005: Install Your Own In-Car Video (Reversing Monitor, In-Car Navigation, etc); Build A MIDI Theremin, Pt.1; Bass Extender For Hifi Systems; Sports Scoreboard, Pt.2; SMS Controller Add-Ons; A $5 Variable Power Supply. May 2005: Getting Into Wi-Fi, Pt.1; Sending data Over UHF CB Radio; Build A 45-Second Voice Recorder; Wireless Microphone/ Audio Link; MIDI Theremin, Pt.2; Sports Scoreboard, Pt.3; Automatic Stopwatch Timer. PLEASE NOTE: issues not listed have sold out. All other issues are in stock. We can supply photostat copies from sold-out issues for $8.80 per article (includes p&p). When supplying photostat articles or back copies, we automatically supply any relevant notes & errata at no extra charge. A complete index to all articles published to date can be downloaded free from our web site: www.siliconchip.com.au June 2005  105 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 Linear power supply for a PC The July 2004 issue of SILICON CHIP had an article on quieting PCs. I find I really dislike switchmode power supplies. They seem to be the most vulnerable part on the computer for breaking down, they make highpitched noises, have straying voltages (although they shouldn’t), and as one reader mentioned, give out stray high voltage shocks which I seem to get zapped by all the time from all sorts of equipment. And in computers, they also have the noisy fan. I just want a stable reliable traditional linear power supply for my PC that can sit quietly as an external box. The initial cost may be a bit higher but hopefully the technology design would last for at least 10 years for computer compatibility and all that time I would have a stable quiet reliable power supply. On the topic of quieting PCs, I’ve found double-sided foam tape excellent for muting hard disk drive (HDD) noise, plus it can be mounted (slappedon) anywhere. I discovered the use of foam tape for a notebook HDD out of necessity when a replacement drive did not have matching screw mounts. The tape permanently secured the drive to the plastic cover despite many removals/insertions into the tight mini IDE plug over several years. If PCs are noisy, so are microwave ovens! Is it within the bounds of SILICON CHIP to advise on making modifications to microwave ovens? Can the fan be altered? The “BEEEEEEP” on microwave ovens is also loud and intrusive. Is it possible to quieten it or make it a pleasant “dit-dit-dit”. The 42V car article was quite informative. I’m sure this will be on us before we know it. Would it be wise for all SILICON CHIP projects that use a positive rail greater than 12V (or even equal to 12V) to be designed to Sad Multi-Spark CDI Story I built the Multi-Spark CDI (SILICHIP, September 1997) for a mate. Everything was OK on the bench but my mate didn’t follow my installation instructions too well and this resulted in Mosfets Q1 and Q2 blowing up in spectacular fashion, along with Q6 and associated collateral damage to the PC board tracks around the Mosfets. I repaired and tested the unit and it was installed correctly. The engine ran beautifully for about 15 minutes then died. On inspection, Q1 had again destroyed itself with gusto and Q2 and Q6 were short circuit between gate, source and drain plus the track between Q1 (drain) and the top of transformer T1 now had a 3mm section missing. He (my mate) is using a GT40 CON 106  Silicon Chip sports coil. Do you think this could be the cause? The article recommends not using them but then says it wouldn’t hurt as the resistance of the sports coil has no effect on the amount of energy dumped into it by the multi-spark system. Any thoughts you have would be appreciated as the distance between me and the unit is several thousand kilometres and I don’t want to repair it again and end up with the same result. • We hate the GT40 sports coil and we can find no reference to it in the original article. It could well be responsible for the damage. Just use the standard car ignition coil. We would not repair it with the damaged PC board. Start all over with a new PC board and parts. use a 42V rail so any project can be equally at home in a “mobile” environment and to ensure compatibility and greater use of designs into the future. (P. R., Assam, India). • A high-power linear supply for a PC would be very bulky and very expensive – it is just not practical. Since the fan in a microwave is normally unique to the particular model, it is unlikely that we would be able to come up with a quiet equivalent. In any case, they normally only operate for a few minutes. It should be possible to quieten the beeper by connecting a suitable resistor or capacitor in series. Warning! – microwave ovens can be extremely dangerous to work on, even when switched off. Be sure you know what you’re doing. As noted in the November 2004 issue, 42V cars are coming but our guess is that it will be at least five years before we see significant numbers in our market. Air-conditioning switch design I am wondering if you can let me know if there is any sort of device on the market to help out with the following problem. I have been asked to come up with some sort of device that will allow the air-conditioning in motel rooms to be switched off when no-one is in the room. I have installed switches to put key-tags in but the patrons break the keys or ask for the second room key. Failing that, they stuff the small shower soaps they are given in the slots! I have installed PIR movement detectors but if the person is a still sleeper the aircon goes off 30 minutes after they fall asleep and goes on when they wake up from the heat. I feel sure I can do something with PIC microcontrollers but I am stuck for a people-sensing device. Any ideas? (L. E., Darwin, NT). • Possibly you need some sort of logic involving a PIR movement sensor and siliconchip.com.au a door switch. The logic says that if the door has opened and closed and the PIR senses movement immediately afterwards, then a person is in the room and the aircon can be on. But if the door opens and closes and no movement is sensed immediately afterwards, then the person has left the room and the aircon can be off. If the occupant leaves the door opened but moves around in the room, the aircon can stay on. Passive preamp has poor overload margin Thanks for publishing the Passive RIAA Preamplifier from Sam Yoshioka in the July 2002 issue – and posted on your website. I like RIAA preamps with passive correction since they tend to have good transient response. However, I have two questions/comments about Sam’s circuit: (1) PSpice simulation indicates that the values in the RIAA network are not correct. The circuit as published seems to have a strong bass lift. A closer approach to the RIAA curve seems possible by reducing the value of the capacitor in series with the 240kW resistor from 0.1mF to 0.027mF. (2) The circuit may sound nice with low output moving magnet cartridges but the input overload margin is small and levels of harmonic distortion are relatively high (calculated value is 0.3% THD at 1kHz and 2mV RMS input). Max input is 20mV at 1kHz, resulting in 3% THD. Anyhow, thanks for a funny circuit which I have added to my large collection. Best wishes from sunny Holland. (A. W., Zuidhorn, Netherlands). • Your simulations may well be correct, as the design was presented as an experimental one. We agree that input overload margin and distortion performance are less than desirable. Much better performance can be achieved with a conventional feedback design. PC switchmode supply conversions I’ve successfully managed to convert a couple of PC switchmode supplies for various requirements and have experienced a few failures along the way. I’ve used a hot-air gun with great success to dismantle the transformers. Simply direct the heat evenly at the siliconchip.com.au Problems With Reversing Monitor As soon as I saw the “Poor Man’s Reversing Monitor” article in the April 2005 issue of SILICON CHIP I knew I had the answer to a problem I have with my 2001 Land Rover Defender 110 wagon – reversing a trailer. So I contacted Jaycar and ordered a Standard Mount 7-inch Monitor and the camera. When the goodies arrived, I first tested the camera using my TV and a 240VAC/12VDC regulated power supply, then on the monitor which was powered by a 12V SLA battery. So far so good. The vehicle is fitted with an additional deep-cycle battery that feeds four cigarette lighter sockets mounted right at the back, each separately fused and perfectly situated for the camera which was connected to one of these sockets using a fused (2A) plug. The monitor was connected to another through the fused line supplied with it. The monitor worked and the camera blew the fuse in the plug but the specs for the camera say current consumption is 60mA! My first thought was that I’d blown the electronics in the camera so I decided to check everything again indoors. The system worked fine. Back to the truck and with the 12V DC power supply connected to the truck’s inverter, the system worked! I upped the fuse rating in core’s outer surface for about 30-40 seconds. The “I” section can then be gently prised away by a sharp blade. Stand the bobbin on its pins and push the core slowly down. Use gloves – it’s hot work. I have two questions. First, why do manufacturers sandwich the secondary windings between two split primaries? Second, some manufacturers use foil screens between windings and some don’t – why so? (M. O., North Balwyn, Vic). • Thanks for the feedback. Interleaving the windings can improve coupling between primary and secondary. However, interleaving increases inter-winding capacitance, so a copper the plug to 3A and still the camera would not work even though the fuse remained intact and there was 12.75V DC showing on my Protek 506! After a bit of head scratching I tried a non-fused cigarette lighter plug through a 3A blade fuse. That did the trick and the system is now working as advertised. Just to make sure, I again tried the camera using the 3A fused plug – again plenty of volts but no picture. My meter shows 0.8W of resistance in the length of the fused plug, most of which would, I presume, be in the spring. This also implies to me that the camera is drawing much more than the specified current and the resistance in the fused lead drops too much voltage, though it’s hard to believe the camera is drawing that much. I haven’t checked this as I don’t have an RCA socket available to make up a test cable. I would be interested in your comments. Is this is worth publishing as a cautionary tale? (R. S., Warragul, Vic). • We think you might have some sort of circulating current between the camera and the monitor. We think that if you just operate the camera by itself there will be no problems but then connecting it to the monitor is what blows the fuse. Maybe you should operate the monitor and the camera on the same battery circuit. strap is sometimes used to reduce this effect. DC-DC converter upgrade With reference to your DC-DC converter in the June 2003 issue, can this circuit be modified to produce more than the maximum rated 2A? My laptop power supply is rated 19V DC <at> 5A and I would like to know if this circuit might be a possible place to start. (S. L., Brisbane, Qld). • The existing 0.1W 5W resistor would need to be paralleled with another 0.1W 5W resistor. The 1000mF and 470mF low ESR capacitors would June 2005  107 RFID Switching Problem I have completed the RFID security module kit (SILICON CHIP, June 2004) and it seems to be working. I would like it to turn the alarm system on and off which requires me to get the kit to turn on and turn off +12V. All I have been able to do is get it to switch +12V for a short period on the door strike mode. Do you have any suggestions? Is there a way to set the circuit up to switch +12V on and off either directly or through a relay? (S. D., via email). • The easiest option might be to connect a relay to the “armed” need paralleling with the same values to increase the ripple rating. L1 would need to be two cores stacked together with 32 turns of 1.5mm or 2mm wire. Finally, D1, D3 and Q1 would need much larger heatsinks. Projector lamp protection circuit I seem to remember an article on soft starts for movie (or slide) projector lamps. This is not the “plink” article on soft starts for normal household lights in June 1986. Am I correct? (R. A., via email). • The only projector lamp protection circuit we can find is one published in the July 1968 issue of “Electronics Australia”, using a Triac controlled by small lamp and LDR to give a softstart. The Lamp Saver from the June controller has failed, it is probable that the Triac is at fault and it should be easy to replace. See our article on repairing dimmers in the November 1996 issue. Fan speed control wanted 1986 issue (also from EA) would be a much better solution as it provides protection against over-voltage as well as soft-start but it does have the disadvantage that it uses a 2N4992 SBS (silicon bilateral switch) which can be hard to get. I have a fan that uses an induction motor and am wondering what would be the easiest way to make it operate more slowly, at around 80% speed? I realise the complications of fully variable speed motor controllers for AC induction motors but am wondering in this case, would a simple ballast resistor or maybe even an auto transformer reduce the RPM slightly so it is not so noisy and not damage the motor? (D. F., via email). • If it is a large industrial fan it will be an induction motor and sadly, there is no easy way of controlling the speed. However, if it is small domestic fan with a “shaded pole” motor it is easy to control the speed using a variant of a conventional Triac dimmer with the addition of a snubber network. Have a look at the Fan Speed Controller published in the January 1990 issue. Universal fan speed controller PIC Programmer regulator substitution Have you ever published a universal fan speed controller? I’ve used commercial ones but they seem to fail regularly – my last commercial unit allegedly rated at 500W capability failed on the first hot day we had. (E. M., via email). • The only ceiling fan controller we have produced was published in January 1990 and used a dimmer module that is no longer available. If your I want to know if I can use an LM7805 instead of the LP2951 in the PIC Programmer described in the November 2003 issue, since it is not available here. (L. R., Caceres, Bolivia). • You could use a 7805 but then you lose the current protection feature provided by the LP2951 and also the low drop-out feature which is desirable if the programmer is to be powered from SC a 9V battery. output. The accompanying diagram shows how to wire it up. Select a 12V DC relay with contacts rated to suit your alarm system. When wiring it up, make sure that the 1N4004 diode is oriented correctly (banded end to +12V), otherwise Q1 (on the PC board) will be damaged. 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. 108  Silicon Chip siliconchip.com.au MARKET CENTRE Cash in your surplus gear. Advertise it here in Silicon Chip. CLASSIFIED ADVERTISING RATES Advertising rates for this page: Classified ads: $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:__________________ siliconchip.com.au FOR SALE 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 MORE ELECTRONIC CONTROL SPECIALS FOR YOU: New – Novus Signal Conditioners both non-isolated and isolated Convert thermocouples, RTDs to 4-20mA or 0-10V Fully programmable. New – Netiom Ethernet and Web I/O monitor and control I/O on the web and generate alarm emails New – Labjack Ethernet/USB Data Acquisition Module features 14 16bit analog inputs, 23 digital I/O, 2 analog outputs and 2 high speed counter. Free software, Labview driver and ActiveX component. Counter and Timers – 7-digit and battery operated Proximity and Photoelectric sensors Temperature and humidity sensors N1500 universal process indicator. Budget priced displays thermocouple, RTD, 4-20mA and 0-5V readings. Fully programmable UHF 433MHz and InfraRed remote relay controller cards Serial and Parallel port relay controller cards Pump and Trip Alarm Controller card. MicroProgrammers for Atmel and PIC chips. 2, 4 & 8 Relay Cards suitable for TTL and Open Collector Outputs DC, Stepper and Servo Motor controller kits Switch Mode and Linear Power Supplies and DC-DC converters. Full details and credit card ordering available at www.oceancontrols.com.au. Helping to put you in control. June 2005  109 Wi-Fi New New New Mark22-SM Slimline Mini FM R/C Receiver TAIG MACHINERY 2.4GHz Antennas Directionals Omnis Stepper motors: 200 oz in $89.00, 330 oz in $110.00 Digital verniers: 150mm $55.00, 200mm $65.00 59 Gilmore Crescent (02) 6281 5660 Garran ACT 2605 0412269707 We also stock: • • • • • 6 Channels 10kHz frequency separation Size: 55 x 23 x 20mm Weight: 25gm Modular Construction Price: $A129.50 with crystal Electronics PO Box 580, Riverwood, NSW 2210. Ph/Fax (02) 9533 3517 email: youngbob<at>silvertone.com.au Website: www.silvertone.com.au Micro Mini Lathes and Mills From $489.00 Panel Antennas Ceiling Antennas Low-loss 50 Ω cable Connectors Pigtails Access Points Masts Amplifiers Power-over-Ethernet External Enclosures Everything you need for WiFi! FREENET-ANTENNAS Web: www.freenet-antennas.com Email: sales<at>freenet-antennas.com Tel: (08) 9319 3275 (int +618 9319 3275) Fax: (08) 9319 1720 (int +618 9319 1720) Select your microcontroller kit and get started... Fax a copy of From $295* RCM3400 this ad and receive a 5% discount on your order! Feature rich, compiler, editor & debugger with royalty free TCP/IP stack • Prices exclude GST and delivery charges. Tel: + 61 2 9906 6988 Fax: + 61 2 9906 7145 www.dominion.net.au 4007 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 SUPERBRIGHT LEDS from just 8 cents each, including new wide angle range! PCBs MADE, ONE OR MANY. Any format, hobbyists welcome. Sesame Electronics Phone (02) 9593 1025. sesame<at>sesame.com.au www.sesame.com.au Foam surrounds,voice coils,cones and more Original parts for Dynaudio,Tannoy and others Expert speaker repairs – 20 years experience Australian agents for products Trade welcome – email for your user ID Phone (03) 9647 7000 speakerbits.com.au 12 volt LED lightbars, great for solar/ camping. Nixie tubes and nixie kits. Lots of other stuff, and always more items being added. www.ledsales.com.au S-Video . . . Video . . . Audio . . . VGA distribution amps, splitters, standards converters, tbc’s, switchers, cables, etc, & price list: www.questronix.com.au Circuit & Design Ideas Wanted Do you have a good circuit idea? If so, sketch it out, write a brief description of its operation & send it to us. Provided your idea is workable & original, we’ll publish it in Circuit Notebook & you’ll make some money. We pay up to $60 for a good circuit so send your idea to: ELECTRONIC ENGINEERING CONSULTANTS: Electronic Hardware and Embedded Software for Industrial Control and Commercial Communications. www.furzy.com.au WEATHER STATIONS: windspeed & direction, inside temperature, outside temperature & windchill. Records highs & lows with time and date as they occur. Optional rainfall and PC interface. Used by government departments, farmers, pilots and weather enthusiasts. Other models with barometric pressure, humidity, dew point, solar radiation, UV, leaf wetness, etc. Just phone, fax or write for our FREE catalog and price list. Eco Watch phone: (03) 9761 7040; fax: (03) 9761 7050; Unit 5, 17 Southfork Drive, Kilsyth, Vic. 3137. ABN 63 006 399 480. ImageCraft C Compilers: 32-bit Windows IDE and compiler. For AVR, 68HC­08, 68HC11, 68HC12, 68HC16. from $330.00 Atmel Flash CPU Programmer: Han- Silicon Chip Publications, PO Box 139, Collaroy, NSW 2097. 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. Advertising Index 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. 555 Electronics...................17,65,73 Send to: Retail Operations Manager - Jaycar Electronics Pty Ltd P.O. Box 6424 Silverwater NSW 1811 Email: jobs<at>jaycar.com.au Altronics................................. 80-83 Jaycar Electronics is an equal opportunity employer and actively promotes staff from within the organisation. Amateur Scientist CD ..................37 ATA...............................................49 Av-Comm...................................111 Dick Smith Electronics........... 20-25 Dominion Electronics............49,110 Elexol...........................................73 Freenet Antennas.......................110 Satellite TV Reception ELNEC IC PROGRAMMERS 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°. Universal and specialised models High quality Realistic prices Large range of adaptors Free regular software updates Windows 95/98/Me/NT/2k/XP 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 PO Box 275, Wentworthville. 2145. Ph: 02 9896 7150 GRANTRONICS PTY LTD www.grantronics.com.au Grantronics.................................111 Harbuch Electronics.....................93 Instant PCBs..............................110 Jaycar ...............IFC, 53-60, 93, 111 JED Microprocessors................5,93 Microgram Computers....................3 MicroZed Computers....................77 Oatley Electronics........................13 Ozitronics.....................................49 Prime Electronics...........................7 dles the 89Cx051, 89C5x, 89Sxx in both DIP and PLCC44 and some AVR’s, most 8-pin EEPROMS. Includes socket for serial ISP cable. $220, $11 p&p. SOIC adaptors: 20 pin $132.00, 14 pin $126.50, 8 pin $121.00. Full details on web site. Credit cards accepted. GRANTRONICS PTY LTD, PO Box 275, Wentworthville 2145. (02) 9896 7150 or http://www.grantronics.com.au SILICON CHIP BACK ISSUES: 193 copies from 1988 with 14 binders. New condition $550 + post. Phone 02 6386 2917 PCB DESIGN Service/Project Devel- opment: Project design from your concept; PCB design – single & multilayer; Circuits professionally drawn; Instruction/Operation Manuals prepared; PIC software design/modification/programming; Prototypes constructed. Email: media.audio<at>optusnet.com.au Phone: 0414 356 409. KIT ASSEMBLY  Each binder holds up to 12 issues  SILICON CHIP logo printed on spine & cover Price: $A12.95 plus $A7.00 p&p per order. Available in Australia only. Buy five and get them postage free. Just fill in & mail the handy order form in this issue; or fax (02) 9979 6503; or ring (02) 9979 5644 & quote your credit card number. siliconchip.com.au RCS Radio.................................110 RF Probes....................................97 SC Perf Elect. For Cars.........79,IBC SC Projects For Cars, Vol.2 .........95 Silicon Chip Back Issues.... 104-105 Silicon Chip Binders..............79,111 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 Silicon Chip Binders Quest Electronics..................93,110 REAL VALUE AT $12.95 PLUS P & P Silicon Chip Bookshop....... 102-103 Silicon Chip Subscriptions...........19 Silvertone Electronics................110 Siomar Batteries..........................51 Speakerbits................................110 Taig Machinery...........................110 Telelink.........................................93 VAF Australia ...........................OBC ____________________________ PC Boards Printed circuit boards for SILICON CHIP projects are made by: RCS Radio Pty Ltd. Phone (02) 9738 0330. Fax (02) 9738 0334. June 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 k s A quic nic System as Car Electro t as difficult or expensive g in ify od TER 4: M electronic systems is no 26 CHAP Understa Systems ur car’s Modifying yo ink you might th tion c Modifica IY Electroni e right wires D : 5 R TE P 30 CHA multimeter and finding th Using a ject Kits nic circuits ctronic Pro uilding Ele to successfully build electro B : 6 R TE P 36 CHA w basic skills You only need a fe ge, volta 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 er h devices o y Cycle Met Injector Dut ty cycles or use it to switc : 9 R TE P A du or ct je in 50 CH el fu itor Digitally mon engine loads nt 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 ing Auto Timer ternal trigger 1: Versatile er with lots of uses and ex 1 R TE P A H le tim 66 C se adjustab A multipurpo lots h ltage Switcalready under the bonnet – 2: Simple Vo 1 nsors ng R hi se e itc TE th P sw g A e in H id off us us ox 72 C ntrol to nitro vices on and Switch de and fan co 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 pose ad 77 C p general-pur A chea 245°C 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 ONTROLLERS MODIFIERS & C Controller LCD Hand – p.105 rrector Speedo Co – p.129 r t ulse Adjuste it to reduce 6: Digital P lenoids in your car – use extra fuel in 1 R TE P A H an l d so ro lse nt 92 C pu co e or th control of assistance ent ne Managem anding Engi s – p.6 Take eering 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 ol l Pu ak-h ta gi pe Di 108 C ve , er ha r et your ca Cycle M Does e Duty tor to use th roller simple adap c Boost Cont ni tro ec El t en or Independ ter t l Fuel Adjus used to adjust air/fuel ra R 19: Digita n be -loop ca ed TE P at os A th cl H r ge C to 112 ge intercep d even chan brilliant volta or swaps an Engine Advanced t – p.14 Managemen A ct meter or inje allow air-flow s tic ris te ac 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 CHA being able to change be st that Imagine ts you do ju 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 tra 149 control an ex r t Controlle Turbo Boos – p.134 Use it to fan speeds vary pump or ture Smart Mix Meter – p.42 Timer rd you’ve gent Turbo atch how ha R 23: Intelliengine idle-down time to m TE P A H C 154 set the turbo timer This been driving Capacitor : Resistor & ENDUM 160 ADD Codes om Jaycar The Kits available fr aland. See Ze Where To Buyoject described in this Abousoktralariae an ew dN 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 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 June 2005  113