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FEBRUARY 2006 £3.80

1. De mcetvama Brushless Prezo Brushless Motor Controller for R C models 9 770268 451128 Smart Card Programmer Kit Theremin Synthesiser Kit KC 5361 15 95 post amp packing KC 5295 14 75 post amp packing Program both the microcontroller and The Theremin is a weird musical instrument that was EEPROM in the popular Gold Silver and invented early last century but is still used today The Emerald wafer cards Cards need to conform Beach Boys classic hit Good Vibrations featured a to ISO 7816 standards which includes the Theremin By moving your hand between the antenna ones sold by Jaycar Powered by 9 12VDC and the metal plate you can create strange sound wall adaptor or 9V battery Instructions outline effects Kit includes a machined silk screened and pre software required which is freely available on drilled case circuit the Internet Kit supplied with PCB wafer card board all electronic x socket and all electronic components components and clear e PCB measures 141 x 101mm English instructions Jaycar cannot accept responsibility for the operation of this device its related software or its potential to be used in relation to illegal copying of Smart Cards in Cable T V set top m Fa 9VDC power supply required a Maplin GS74R 9 99 i i i boxes Ey i i Universal High Energy Ignition ti KC 5419 27 75 post amp packing 4 A high energy 0
2. 50 00 94 25 Matching enclosure 050008 71 10 25 19 30 Further products from Elektor Electronics READY BUILT PROJECTS ClariTy 300 W Class T Amplifier 030217 91 Amplifier board with SMDs pre fitted cores for L1 amp L2 Flash Microcontroller Starter Kit 010208 91 ready assembled PCB incl software cable adapter amp related articles 69 00 112 50 Gameboy Digital Sampling Oscilloscope GBDSO 990082 91 ready assembled board incl the PC software and related articles 103 00 183 00 34 50 55 70 Elektor Electronics Publishing Regus Brentford 1000 Great West Road Brentford TW8 9HH United Kingdom Tel 44 0 208 261 4509 Fax 44 0 208 261 4447 Email sales elektor electronics co uk Kits amp Modules OBD 2 Analyser July August 2005 Kit of parts including PCB programmed controller compo nents including IC7 IC3 PCA82C250 12 V enclosure and RS232 cable OBD cable not included 050092 71 52 50 96 95 OBD cable 050092 72 27 55 51 95 GPS Receiver on USB June 2005 Complete kit not inclu ding IC3 with Lassen iQ receiver and extra long cable CD with software and water proof antenna case 040264 71 77 65 146 25 050058 11 Disk PIC source amp hex code 050058 41 PIC16F84 programmed 050222 1 PCB 050222 41 IOW24 P programmed Telephone Supervisor 050039 41 PIC16F628 20 P programmed 050039 81 CD ROM PIC hex amp source codes
3. on your PC matches Once a week what we describe here Install the KD30 moni tor debugger first fol Download locaton lowed by the NC30 C Renesas Tools Website compiler with the HEW Local or nctwork dive development environ ment and an update Installation in this order is important so the HEW will find the debugger already installed and link it in properly Next install the debugger package in order to integrate the debugger into the development environment Later on you only need to start the HEW in order to have everything together on your screen Finally you have to install the Renesas Flash Development Toolkit FDT which enables you to download finished programs to the microcontroller After you insert the CD a product summary in PDF format will be displayed first You should see the main directory of the CD after you close the product summary Alternatively you can rightclick on the drive icon and select Open in order to skip the PDF intro The most important directories on the CD are Software and Sample_NC30 They contain all the necessary programs which should now be installed and the initial sample projects 1 KD30 The executable installer file KD30V410R1_E_20041203 exe is located in the Software kd30400r1 directory on the CD Start the installation and confirm the default path C MTOOL 2 NC30 Run the setup file nc30wav530r02_2_ev exe in the Software nc30v530r0_hew directory on
4. 10uF 63V radial T2 T4 BC327 i C3 C5 100nF ceramic T5 T6 IRF640 or IRFB260N C6 100uF 25V radial IC1 4047 C7 1nF 400V MKT IC2 78LO9 l C8 AuF7 100V MKT lead pitch l 27 5mm Miscellaneous l k K1 K4 2 way PCB terminal block lead 2 2006 elektor electronics pitch 5mm K5 K6 way PCB terminal block lead pitch 7 5mm TRI 2 x core B64290 182 X830 N30 50 x 20 mm e g Epcos Schuricht cat no 330603 2 x 12 turns 0 8mm ECW primary approx 2 times 1 5m 2 x 75 turns 0 5mm ECW secondary approx 2 times 8m F1 fuse 5A T slow with PCB mount holder F2 fuse 1A T slow with PCB mount holder 2 x heatsink type SK129 63 5 STS Fischer Dau Components 63 5mm high 4 5K W Mains transformer secondary 2 x 30V 225VA e g Amplimo Jaytee 68017 PCB ref 050192 1 from The PCBShop see text 65 Figure 5 This is what can happen if R7 and R8 are too close to the circuit board are closer to the board they may cause charring of the PCB Figure 5 Other types of rectifier diodes may possibly be used as long as they are pin com patible types in TO220 packages and COMPONENTS LIST Cascade board Capacitors C1 C20 5600pF 2000V Panasonic I I I I I High Voltage Disk Capacitor Y5P kL can handle at least 200 V and 7 A Assembling the cascade boards is quite straightforward see Figure 6 and Figure 7 A combined shape is used on the board for the diodes
5. Assembled Order Code A453179 18 96 Bi Polar Stepper Motor wien Drive any bi polar stepper a motor using externally sup plied SV levels for stepping and direction control These usually come from software running on a computer al Supply 8 30Vde PCB 75x85mm Kit Order Code 3158KT 14 96 Assembled Order Code AS3158 27 96 CREDIT CARD SALES Here are just a few of the controller and data acquisition and control units we have See website for full details Suitable PSU for all units Order Code PSU345 9 95 Rolling Code 4 Channel UHF Remote State of the Art High security 4 channels Momentary or latching relay output Range up to 40m Upto 15 Tx s can be learnt by one Rx kit in cludes one Tx but more avail able separately 4 indicator LED s Rx PCB T7x85mm 12Vde 6mA standby Two and Ten channel versions also available Kit Order Code 31B0KT 39 96 Assembled Order Code AS3180 47 96 Computer Temperature Data Logger 4 channel temperature log a ger for senal port C or F Continuously logs up to 4 zi separate sensors located T 200m from board Wide range of free software appli cations for storing using data PCB just Jmm Powered by PC Includes one D51820 sensor and four header cables Kit Order Code S145KT 16 96 Assembled Order Code AS39145 23 96 Additional DS1620 Sensors 3 96 each DTMF Telephone Relay peace Call your phone
6. E Clo Figure 7 Selecting the baud rate program you must use Build All to compile the program and then use FDT to download it to the microcontroller again A sense of time Now we come to the crystal oscillator of the microcontroller The port toggle sample program uses the crystal oscil lator which runs at 20 MHz As already mentioned there are also two internal RC oscillators with frequen cies of 125 kHz and 8 MHz respec tively In fact the microcontroller always starts up with the low speed Programming Optisna ring oscillator enabled If you look at the data sheet for the R8C 13 you will see the complicated clock generation arrangement for the R8C with a total of three oscillators and several optional divider stages The port toggle sample project demonstrates how to switch from the 125 kHz oscillator to the crystal oscil lator pred 1 Protect off cm13 1 Xin Xout cm15 1 XCIN XCOUT drive capacity select bit HIGH Phe FLASH Digapkopra Toda afer a deacra peii finally there is another wait Even if you don t have any experience with C you can right away see where you could make some changes For instance you could shorten the wait loops to make everything run a bit faster For example you could set the count to 25 000 instead of 50 000 You could also try reducing the count to 2 and see how fast it runs then You can even remove the wait loops entirely by using the
7. Once the secondary is wound it must be insulated You ll have to buy special insulating film for that Do not use adhesive tape electrician s tape or anything of that sort The insulation must have a certain mechanical strength and electrical insulation rat ing and it must be able to handle a thermal load The symmetric primary winding is considerably easier to wind To ensure good symmetry wind the two wires in parallel see Figure 8 Two 1 5 m lengths of 0 8 mm enamelled copper wire will be adequate for the primary Winding Start the winding next to the centre tap of the secondary and wind in the direction of one end of the sec ondary winding After six turns cross over to a point on the core at the same distance from the other end of the sec ondary as where you stopped with the sixth turn Give the two wires a twist during the crossover so the polarity of the primary winding is correct Other wise you ll create a solid short circuit because the core will immediately become saturated Finish the primary by winding the remaining six turns to arrive back at the centre tap of the sec ondary The transformer should have a reasonably symmetric appearance For our first test we used a core with a diameter of 50 mm and a height of 20 mm with N30 core material www schuricht de Unfortunately it proved to not provide sufficient power so we glued two cores together using 68 two component epoxy glue see the photo o
8. domly to surrounding objects and we do not regard that type of experiment ing as something that can be respon sibly suggested as an example When the subject of high voltage experiments is mentioned many peo ple have a mental image of two spheres with sparks jumping between them An example of such a device is the Van De Graaf generator which was built by Dr Robert J Van de Graaf and could generate 5 million volts Our ambition here is quite a bit more modest A device that produces a well defined arc between two conductors spaced a small distance apart is safer A nice example of this is the Jacob s ladder An electric arc between two long conductors heats the air if it has sufficient energy and the hot air pro duces enough convection to cause the arc to move upward If the two conduc tors are arranged in the form of an extended V with the distance between the conductors increasing in the upward direction the applied voltage will ultimately be too low to maintain elektor electronics 2 2006 cS 2 2006 elektor electronics the arc After the arc is extinguished a new arc will be formed again at the bottom In principle this can be achieved with little or no electronics All that s needed is a power supply that can provide 10 15 kV at 20 40 mA which amounts to a hefty mains transformer that can deliver suffi cient voltage and power Of course the transformer must meet r
9. 0 208 261 4447 Internet www elektor electronics co uk EL02 subscriptions elektor electronics co uk ORDERING INSTRUCTIONS P amp P CHARGES Except in the USA and Canada all orders except for subscriptions for which see below must be sent BY POST or FAX to our Brentford address using the Order Form overleaf On line ordering http www elektor electronics co uk Readers in the USA and Canada may but are not obliged to send orders except for subscriptions for which see below to the USA address given on the order form Please apply to Old Colony Sound for applicable P amp P charges Please allow 4 6 weeks for delivery Orders placed on our Brentford office must include P amp P charges Priority or Standard as follows UK 4 00 Europe 5 00 Standard or 7 00 Priority Outside Europe 8 00 Standard or 12 00 Priority HOW TO PAY All orders must be accompanied by the full payment including postage and packing charges as stated above or advised by Customer Services staff Bank transfer into account no 40209520 held by Elektor Electronics Publishing Segment b v with ABN AMRO Bank London IBAN GB35 ABNA 4050 3040 2095 20 BIC ABNAGB2L Currency sterling UKP Please ensure your full name and address gets communicated to us Cheque sent by post made payable to Elektor Electronics Publishing Segment b v We can only accept sterling cheques and bank drafts from UK resident customers or subscribers
10. 1000 Great West Road Brentford TW8 9HH United Kingdom Fax 44 0 208 2614447 Email editor elektor electronics co uk Subject hexadoku 02 2006 The closing date is 1 March 2006 Competition not open to employees of Segment b v its business partners and or associated publishing houses Solve Hexadoku and win Correct solutions qualify for an E blocks Starter Kit Professional worth 248 55 and three Elektor Electronics Shop Vouchers worth 35 each We believe these prizes should encourage all our readers to participate and requires only the num bers in the grey boxes to be sent to us see below The puzzle is also available as a free download from our website Magazine gt 2006 February 065043 1 79 SSS G0 FISHOWCASE To book your showcase space contact Huson International Media aco Palen ot Ce he eel hh Fax 0044 0 1932 564998 ALLGOOD TECHNOLOGY www allgoodtechnology com Low medium volume sub contract assembly SMT specialist since 1990 Customers include military aerospace etc 0402 to BGA capabilities automatic assembly and hand built prototypes AVIT RESEARCH www avitresearch co uk USB has never been so simple with our USB to Microcontroller Interface cable Appears just like a serial port to both PC and Microcontroller for really easy USB connection to your projects or replacement of existing RS232 ATC SEMITEC LT
11. 14 A powerful magnet is only half the battle Like an elec tric circuit the magnetic circuit must be short and of adequately large cross section low magnetic imped ance This is best achieved using a large amount of iron which is also unfortunately heavy and responsi ble for further losses When an iron core which in con ventional motors also carries the windings rotates in a magnetic field there are iron losses which comprise losses due to hysteresis and losses due to eddy currents and which are speed dependent It is not possible to prevent these losses and so the efficiency of the motor decreases with increasing speed To reduce the losses as far as possible motor manufacturers use high quality iron a soft magnet and a large number of segments lron cores are never solid but divided lengthwise into as many layers as possible isolated from one another and thus cutting the path of eddy currents Eddy cur rents arise not only in the core but also in all other elec trically conducting parts of the motor including the magnet and the windings These are reduced by the rather involved technique of segmenting the magnet and making the windings from a number of fine parallel wires or a braid rather than a single solid conductor The desire to avoid iron core losses has prompted the invention of iron free motors but these do not exactly offer high levels of torque The ideal motor then has yet to be invented we
12. LCM First Server 5 20 13 10 24 65 NO 349 DECEMBER 2005 From A to D via USB 7 95 9 40 8 20 6 90 9 75 14 95 WAE oa Zoo Micro Webserver with MSC1210 Board 030060 91 Microprocessor Board ready assembled 044026 91 Network Extension Board ready assembled 75 90 142 95 44 50 83 95 NO 348 NOVEMBER 2005 Remote Control by Mobile Phone 044026 92 Combined package 030060 91 amp 044026 91 amp related articles LPC210x ARMee Development System 040444 91 Processor board ready made and tested 25 50 48 05 NO 351 FEBRUARY 2006 Brushless Motor Controller 117 50 220 95 040415 1 PCB 6 20 11 65 040415 11 Disk PIC source amp hex files 5 20 9 75 040415 41 PIC16F84A 20 P programmed 10 30 19 50 Synchronous Servos 020031 11 Disk project software 5 20 8 9 75 020031 41 AT90S2313 10PC programmed 7 85 14 85 050157 41 ST7MC1 programmed 3 80 7 15 A 16 bit Tom Thumb 050179 91 R8C Starter Kit 8 30 15 60 NO 350 JANUARY 2006 95 watt Laptop PSU Adaptor 050029 1 PCB 4 80 9 05 Automatic Attic Window Controller 050139 11 Disk PIC source amp hex code 5 20 9 75 050139 41 PIC16F84A 201 P programmed 13 10 24 65 030451 72 LCD Modue 2x16 characters 7 25 13 05 030451 73 PLED Module 2x16 characters 25 50 48 05 SMD Reflow Soldering Oven 050319 11 Disk source and hex code 5 20 9 75 050319 41 AT89C52 24JI programmed 7 60 14 25 030451 72 LCD Modue 2x16 characters 7 225 13 05 030451 73 PLED
13. Lo a e E yar ae application complete with forward and back annotation Design and rules checks at all stages ensure integrity at all times Professional manufacturing outputs allow you to finish the design process with ease e E eee Stop press Stop press Stop press Stop press r ese as Easy PC imports Eagle files as well as Tsien Boardmaker 2 files E Component Clearance Check call for a brochure prices amp CD on 44 0 1684 773662 we ae My E Alphanumeric Pin Name or e mail sales numberone com ye Da N fi 4 Designed fi you can also download a demo from Windows XP Windows NT Number One Systems Oak Lane Bredon Tewkesbury Glos United Kingdom GL20 7LR UK PicoScope 3000 Series PC Oscilloscopes The PicoScope 3000 series oscilloscopes are the latest offerings from the market leader in PC oscilloscopes combining high bandwidths with large buffer memories Using the latest advances in electronics the oscilloscopes connect to the USB port of any modern PC making full use of the PCs processing capabilities large screens and familiar graphical user interfaces High performance 106656 semoaling rate amp 200MHz bandwidth 1MB buffer memory a 3708 1205 l lastaidtt SOM 100Mit FOM High speed USB 2 0 interface Ssmp sg rota repetitis 2505 505 1008 Sompiheg rete lnpgie adot SOME s SOOM JOME amp Advanced display amp trigger modes Chesedis EED Poln triggerflg gee Roen
14. Online ordering through our website is SSL protected for your security January 2006 eseo osocsocsooocoooocoocsocoocoocoocoocoooocoooocooooooooo ooo coocoo ooo ooo oono i i i SUBSCRIPTION CONDITIONS The standard subscription order period is twelve months If a perma nent change of address during the subscription period means that copies have to be despatched by a more expensive service no extra charge will be made Conversely no refund will be made nor expiry date extended if a change of address allows the use of a cheaper service Student applications which qualify for a 20 twenty per cent reduc tion in current rates must be supported by evidence of studentship signed by the head of the college school or university faculty A standard Student Subscription costs 33 50 a Student Subscription Plus costs 40 40 UK only Please note that new subscriptions take about four weeks from receipt of order to become effective Cancelled subscriptions will be subject to a charge of 25 twenty five per cent of the full subscription price or 7 50 whichever is the higher plus the cost of any issues already dispatched Subsciptions cannot be cancelled after they have run for six months or more January 2006 leading the way lektor lectronics CD ROM Elektor 2005 This CD ROM contains all editorial articles with the exception of New Products items published in Elektor Electronics magazine Volume 2005 Using t
15. Req R1 R2 R1 R2 In many cases a theoretical value required in a circuit will deviate somewhat from off the shelf val ues in the E series In analogue fil ters for example maintaining the exact value is a must and even an E96 value is usually too inaccu rate The obvious solution to the problem is then to take the next higher E96 value and connect a high value in parallel in order to arrive at the computed value In those cases you know the desired value as well as the nearest E96 value A formula similar to the one above may then be used to calculate the required parallel resistor where R is the desired value Re is the E series value e g E96 but equally E12 or E24 Rp is the unknown resistance From the above basic formula we can derive R Re Rp Re Rp Re Rp Re R Rp R Re Ro Rp R RER So we get for Rp Rp Re R Re R where R gt R This equation should be easy to remember as it looks very much like the textbook version for par allel resistances Of course there are programs to calculate all pos sible combinations but using a simple desktop calculator is often quicker and more convenient When the second resistor becomes too large for example larger than 1 MQ or 10 MQ you may decide to take a slightly higher value as a starting pint for the E series calculation Parallel connection of resistors i e pre ferred over series connection in the case of modificati
16. Timer Interrupt project If you re trying to use a timer for the first time you can of course pore through the R8C 13 data sheet but it s better to start with a working bit of code from a sample pro gram and then read the relevant por tions of the data sheet while trying out your own modifications Besides timer initialisation the Timer Interrupt sam ple program shows how to implement an interrupt function in C You ll find even more sample programs in the application notes on the CD If you re now eager to generate your own personal project you can find the necessary information on the Elektor Electronics website at www elektor electronics co uk look for the R8C link in the right hand column There you will find a simple example that explains in step by step fashion how to generate your own application pro gram without relying on an existing project And if you still have questions a dedicated Forum topic for the R8C starter kit has been set up on the Elek tor Electronics website 050179 2 Reference www glyn com elektor electronics 2 2006 I Lichfield Electronics a The Com Exchange Conduit St Lichfield Staffs W513 6JU oS Tel 01543 2566684 Online www LichfieldElectronics co uk Partial Stock List Silage Yah Halio Line Tracking Momsr 1288 Hims PS Dei Malrinrcer kit Dela sadar kin AMDIPM Hadin kit bafrared Musi Player IE Shere a moriner Victal Detector Kii Munic Firei Postcard C
17. amplifier the triangle amplitude and again the symmetrical output signal between the bridge halves These were all correct except for the output signal as we had established earlier a SOO Ly DAS Cea oa 1 aoc G The designer also suggested overshoot in the output filter as a possible cause for the strong distortion but in our opinion the output filter could never cause distortion this bad We were not making much progress here According to the designer every thing was in order all the samples that he had built gave him comparable measuring results but according to us something didn t smell right More measurements After we had spent all this time on this amplifier we could not just abandon it and we decided to investigate further to determine the cause of the amplifier behaviour The preceding measure ments gave the impression that the input amplifier the internal regulated power supply and the PWM modulator were all largely correct But there was still no explanation for the severely dis torted output signal from the bridge halves To check the signals to the driver IC for the MOSFETs we meas ured those via a small low pass filter 10 kQ 100 pF The signal Figure 4 did not show any asymmetry on either input to the HIP4082 the noise is the remainder of the PWM modulation This signal is not quite sinusoidal because the neg ative feedback in the output stage compensates and this results in a de
18. each MOS FET P gate must be brought to an approximate voltage V minus the Vpeon On the BC817 or approximately T34 T39 BC8 17 40 T40 T42 T43 BC807 40 T41 not fitted Miscellaneous K2 K3 see text PCB ref 050157 1 and 2 from The PCBShop Controller configuration PWM 24 kHz Brake OFF Soft start ON Auto LiPO detect 3 cells 12 6V BEC OFF Phase advance at min rate 18 degrees at max rate 30 degrees 29 HANDS ON RC MODELLING The environment A small budget makes it easier to take risks Development tools are free only the debugging programming interface needs to be paid for Softecmicrosystems http www softecmicro com proposes a debugging interface used to emulate and program all of the devices of the whole ST7 flash family Finally it is possible to obtain a ST7MC starter kit www softecmicro com products html type detail amp title AK ST7FMC includes a micro board a high voltage power stage a brush less motor and software operating in Windows to learn and get practice on this type of application 300 to 400 mV while the MOSFET N gates must be at almost zero voltage Next we can apply a voltage of V on pins 2 4 and 6 to put the MOSFET P to ON closed switch Verify that we have approx 300 to 400 mV voltage at each gate Disconnect the V from pins 2 4 and 6 MOSFET P OFF and short circuit pins 1 3 and 5 to ground Then verify that we have an approxi mate v
19. it s not really necessary for the power level of this setup but may become necessary if you make a heavy duty stage since it s only about adding parallel MOSFETs We can then solder the two power supply cables to the battery and the cables to the three phases of the motor Finally we still have to proceed to the installation of connectors K1 and K2 on the power IC2 ST7MC1 programmed Publishers order code 050157 41 IC3 IC4 14941 BAOSFP Miscellaneous X1 8MHz quartz crystal K1 K2 see text K3 3 way SIL header with 1 jumper PCB ref 050157 1 from The PCBShop Power driver board Resistors R25 R30 2700 R31 R36 1kQ R37 R48 2400 Capacitors C1 C11 C17 100nF C2 C10 not fitted C18 470pF 6V3 Semiconductors D1 D2 D3 BATS54A D4 D5 D6 BATS54C T16 T21 FDS6675 122 127 BSS138 2N 7002 T28 T33 PHK12NQO3 LT board section It is recommended to do a small opera ting test before coupling our two boards To do this solder three 10 KQ pull down resistors between ground and pins 2 4 and 6 at K2 as well as three other 10 kQ pull up resistors bet ween V and pins 1 3 and 5 in order to switch all MOSFETS to OFF open switch With the help of a small power supply from 5 to 15 V current limited 500 mA for example avoid batteries or rather use a series resistor from 20 to 50 Q for example to power the cir cuit first verify the levels present on each power MOSFET gate
20. 01590 681511 email info fored co uk Forest Electronic Developments 12 Buldowne Walk Sway Lymington Hampshire 5041 6DU www fored co uk 2 2006 elektor electronics info fored co uk 45 MODDING amp TWEAKING Do you have an old PC that functions as a server and is turned on 24 hours per day That takes quite a lot of energy It can be done much cheaper using a modified router We do need to add some extra storage space but that isn t a problem In this article we ll show you how you can add a USB port to an inexpensive router Apart from providing the required memory expansion it also offers the possibility for many other applications The UK and many other counties are currently swamped with A DSL and cable Internet connections Most of these connections only permit one PC at a time to connect to the Internet There are several ways round this problem allowing a number of PCs to use the Internet simultaneously The 46 most popular solution makes use of a so called router This is a small box into which the Internet cable plugs A number of PCs can also be connected all of which then have access to the Internet These boxes are often consid ered as black boxes It does what it s designed to do and it doesn t really matter what s inside They re rarely opened since it hardly makes sense to repair them For less than twenty pounds you can get a new one Because of this only a few
21. 351 February 2005 ISSN 0268 4519 Elektor Electronics aims at inspiring people to master electronics at any person al level by presenting construction projects and spotting developments in elec tronics and information technology Publishers Elektor Electronics Publishing Regus Brentford 1000 Great West Road Brentford TW8 9HH England Tel 44 0 208 261 4509 fax 44 0 208 261 4447 www elektor electronics co uk The magazine is available from newsagents bookshops and electronics retail outlets or on sub scription Elektor Electronics is published times a year with a double issue for July amp August Under the name Elektor and Elektuur the magazine is also published in French German and Dutch Together with franchised editions the magazine is on circulation in more than 50 countries International Editor Mat Heffels m heffels segment nl Editor Jan Buiting editor elektor electronics co uk International editorial staff Harry Baggen Thijs Beckers Ernst Krempelsauer Jens Nickel Guy Raedersdorf Design staff David Daamen head of design Ton Giesberts Paul Goossens Luc Lemmens Karel Walraven Editorial secretariat Hedwig Hennekens secretariaat segment nl Graphic design DTP Ton Gulikers Giel Dols Managing Director Publisher Paul Snakkers Marketing Margriet Debeij m debeij segment nl lektor lectronics leading the way Home Automation This CD ROM provides an overview
22. 9ms spark burns fuel faster and acu more efficiently to give you more power This versatile kit can be connected Wafer Card to conventional points twin ZZ 8800 3 85 post amp packing points or reluctor ignition This is a multi chip smart card based systems Includes PCB case on the PIC 16F84A and is coupled with and all electronic a 24LC16B EEPROM compatible with components C N most reader programmer units available including the programmer above BS 5080 7 00 post amp packing W Stock projects are available in kit form e 00o Electronic Components Smart Fuel Mixture Display ae eee KC 5374 8 95 post amp packing This new smart version has a few additional touches such as auto dimming for night driving emergency lean out alarm and better circuit protection Another great feature is the dancing display which operates when the ECU is operating Power Products amp Accessories in closed loop Kit supplied with PCB and all electronic Computer amp Telecoms components Accessories e Car must be fitted with air flow and EGO sensors standard Burglar Alarms amp on all EFI systems for full functionality Surveillance Equipment i Gadgets amp Unique Gifts Recommended box a gt UB3 1 95 each Post and Packing Charges Order Value Cost 20 49 99 f5 50 99 99 10 100 199 99 20 200 499 99 30 500 40 Max weight
23. An example is the use of a strong magnetic field If permanent magnets are used then the main question is one of material cost Modern DC motors use neodymium NdFeB magnets which have up to ten times the energy product B x H of normal ferrite SrFe magnets This increases torque and reduces the specific rotational speed n c Neodymium magnets can achieve remanence values of up to 1300 millitesla mT Unfortunately they are more temperature sensitive for higher thermal robustness cobaltsamarium magnets for example SmCo5 alloy can be used although these offer a remanence of only up to about 1000 mT Figure 3 Figure 2 A high fill factor is important here there is some room for improvement 17 DC MOTORS Figure 3 Large ferrite magnets are being superseded by small neodymium based magnets Magnets Yj iP ATT Bearing Figure 4 Diagram of a conven tional iron cored motor Figure 5 The brush system in a mechanically commu tated DC motor is com plex lossy and prone to wear Figure 6 Diagram of a mechani cally commutated iron less core motor Winding Bearing PETTY Figure 7 Diagram of a brushless motor with interior rotor Back iron completing magnetic circuit Yj Brushes ltl Connections i ommutator 050321 12 Armature potted coil Magnets Connections Commutator 050321 13 Connections Back iron Magnets Back iron 050321
24. Contents of Starter Kit e 8988252 Flash Microcontroller board ready assembled and tested PCB e 300 mA mains adapter e Serial cable for COM port 69 00 US 112 50 e Software bundle on CD ROM e Article compilation on CD ROM More information on www elektor electronics co uk GOR AMPLIFIERS TO N i i f y j y i f f i f i y y d f y i i f i j i A n i i i 1 A 1 A N v A ij i y j i f i a f I d i i i i f f i A f i i i 1 oN i l s A i bd N h 4 y r m i k f N y y i i EEI A f N N N i y 7 y N N T N y f i N d y a d q 4 l y q j A p A q Da at A f 7 Kt p if B L J A Lae ee i a Ea oo E Ee E CE a faa NX A few months while scrutin ising a great design for a pulse width modulated audio amplifier with a 2x100 W power rating and a very small enclosure we were immediately very enthusiastic and thought this design would certainly deserve a place pos y 7 J i mm in Elektor Electronics So our resident audio j x Some designer was going to put the circuit through its paces The results were most unusual and this led to an extensive investigation of what was
25. First contact In the next issue of Elektor Electronics we will describe a complete develop ment system with RS232 and USB interfaces But you naturally don t want to wait that long to try out the board For that reason we describe a solution here that only requires a few components from your parts bin Figure 2 The fully assembled board with the pin headers fitted e a source of 5 V power preferably sta bilised by a voltage regulator e an inverting level converter for con nection to the RS232 port e a pushbutton reset switch e a mode switch to select the program ming mode oO TR 1O OTN DM OQ TS E g 78L05 9V Jt gt o E LO 1N4004 oe The microcontroller board feeds out all the microcontroller leads one to one cee ee eee As we already mentioned a crystal a few capacitors and some resistors are fitted on the board The schematic dia Figure 3 The circuit diagram of a minimal system for initial tests gram in Figure 3 shows only the con 40 elektor electronics 2 2006 nections that are essential for a quick start so you can get your bearings as fast as possible The connections not shown in the figure must always remain open Figure 4 shows an exper imental setup on a prototyping board The serial port of the PC is connected here via transistor inverters Although a MAX232 could be used just as well for this purpose the transistors will probably be easier to find in your parts bin A BC548C N
26. Form in the Readers Services section in this issue Elektor Electronics Publishing Regus Brentford 1000 Great West Road Brentford TW8 9HH United Kingdom Tel 44 0 208 261 4509 See also www elektor electronics co uk elektor electronics 2 2006 TL LL EasyS HC SERIAL COMMUNICATIONS SPECIALISTS Test and Measurement Solutions a Affordable CAN Bus Solutions CANUSB is a very small dongle that plugs into any PC USB Port and gives an instant CAN connectivity This means it can be treated by software as a standard COM Port serial RS232 port which eliminates the need for any extra drivers or by installing a direct driver DLL for faster communications and higher CAN bus loads CAN232 is a very small dongle that plugs into any PC COM Port or any other RS232 port in an embedded system and gives an instant CAN connectivity This means it can be treated by software as a standard COM Port serial RS232 port which eliminates the need CAN USB amp CAN 232 for any extra drivers Sending and receiving can be done in standard affordable CAN Bus to USB and RS232 SCID interface solutions priced from 61 00 CAN 232 Bronze Prize Winner NASA Tech Briefs 2004 _ Products of the Year USB Instruments PC Oscilloscopes amp Logic Analyzers Our range of PC Instruments may be budget priced but have a wealth of features normally only found in more expensive instrumentation Ou
27. Head Office Email advertenties elektuur n Advertising rates and terms available on request Copyright Notice The circuits described in this magazine are for domestic use only All drawings photographs printed circuit board layouts programmed integrated circuits disks CD ROMs software carriers and article texts pub lished in our books and magazines other than third party advertisements are copyright Segment b v and may not be reproduced or transmitted in any form or by any means including photocopying scanning an recording in whole or in part without prior written permission from the Publishers Such written permis sion must also be obtained before any part of this publication is stored in a retrieval system of any nature Patent protection may exist in respect of circuits devices components etc described in this magazine The Publisher does not accept responsibility for failing to identify such patent s or other protection The submission of designs or articles implies permission to the Publishers to alter the text and design and to use the contents in other Segment publications and activities The Publishers cannot guarantee to return any material submitted to them Disclaimer Prices and descriptions of publication related items subject to change Errors and omissions excluded Segment b v 2006 Printed in the Netherlands T a DO 12 95 US 22 90 DOMOTIQUE mi m Order now using the Order
28. L1 C2 and C3 because the peak cur rents for switching the MOSFETs are greater than what the IC can supply D3 protects the output of the 78L09 against any spikes that may be present and D4 does the same thing for the input volt age of the voltage regulator The main supply voltage is provide by four fast rectifier diodes which can handle 7 A at a voltage of 1 000 V This working voltage is more than what is strictly necessary but it was chosen to be on the safe side The diodes are located next to each other at the edge of the circuit board so they can be eas ily fitted to a small aluminium plate for cooling if necessary electrically iso lated of course C12 C15 filter the diode switching spikes Standard MKT capacitors are used for this purpose because they have higher working voltages than normal ceramic types Three terminal blocks K3 K5 are located on the circuit board for con necting the mains transformer The fourth terminal block K6 is used to connect the mains transformer to the mains circuit via fuse F2 Now let s return to the output of the converter One way to convert an AC voltage to a high DC voltage using standard components is to use what is called a cascade circuit That consists of a series of diode capacitor pairs that increase the output voltage by the peak value of the applied AC voltage for each section of the cascade see Fig ure 2 A drawback of this arrangement is that the
29. Module 2x16 characters 25 50 48 05 Timer Switch for Washing Machine 050058 1 PCB 8 90 16 70 NO 347 OCTOBER 2005 27C512 Emulator 030444 11 Disk project software 5 20 9 75 030444 31 EPM7064SLC84 15 programmed 27 50 51 95 030444 41 AT90S8515 4PC programmed 15 10 28 35 Colossus Jr 040267 11 Disk PIC source code 5 20 9 75 040267 41 PIC12F675 C P programmed 410 5 35 Flash Lock for PCs 050107 41 PIC16F628A I SO programmed 5 00 9 45 050107 81 CD ROM project software 6 90 12 95 Products for older projects if available may be found on our website www elektor electronics co uk home construction fun and added value WTOC SNEAK PREVIEW Theme Plan for 2006 Recycling Reverse Engineering C Programming Mini Course Many electronics enthusiast have not only embraced microcontrollers but Power Supplies Safety also written the odd program Although assembly code is great for rela Soldering Etching tively short programs when it comes to large software projects or sub programs involving maths and other advanced functions it is often bet July August Summer Circuits ter to turn to a higher programming language like C which has been the September Essien Teie Measurement industry standard for a number of years already The March 2006 issue Ocober of Elektor Electronics comes with a free booklet that teaches you the basic elements of programming in C including a few noteworthy examples for our low cost R8C micr
30. That requires only a diode and capacitor for each half bridge Internally the output stage for the upper MOSFET is driven via a level shifter The power supply for the output stage effective ly the bootstrap capacitor goes up with the source of the upper MOSFET when this one goes into conduction pins AHS BHS When the bottom MOSFET conducts the bootstrap capacitor is charged via the diode and bottom MOSFET from the low voltage power supply The power supply for the bridge may be up to a maximum of 80 V and at the maximum sup ply voltage for the IC of 15 V Vpp the power supply voltage for the upper drive stages can reach up to 95 V pins AHB BHB The datasheet is not very clear as to the exact operation of the IC More information can be found in application note an9611 A DC AC Isolated Battery Inverter using the HIP4082 The time that the bootstrap capacitor is allowed to charge up is clearly only determined by the pulse width of the input signal that is the length of time that the input is low When the input signal is high the bootstrap capacitor will discharge and as a result the gate drive voltage of the upper MOSFET also reduces Intersil indicates that for the HP4082 as a rule of thumb that this capacitor should be 10 times bigger than the capacitance of the MOSFET Viewed logically the size of the capacitor at 100 modulation is more dependent on the low frequency modulation of the PWM signal You could of course specify a minimum
31. This book contains chapters on basic theory microphones and musical instruments various types of amplifier loudspeakers effects equipment recording techniques lighting equipment the rehearsal room and faultfinding and small repairs It also contains a useful glossary of terms used in sound engineering and a list of adjectives describing sound colouring 1 800 optocouplers All databank applications are fully interactive allowing the user to add edit and complete component data 12 95 US 22 90 PC Interfaces under Windows Robotics A large collection of data sheets software tools tips tricks and Internet links to assorted robot constructions and general technical infor mation All aspects of modern robotics are covered from sensors to motors mechanical parts to microcontrollers not forgetting matching programming tools and libraries for signal processing 12 05 US 21 25 PC Interfaces can be used for more than just the printer mouse modem and joy stick While it was relatively easy to directly access PC interfaces using a DOS com puter under Windows things are not all that simple This book CD ROM incl shows you how it can be done The authors describe the DIY construction and programming of a number of highly interesting circuits Audio Collection 2 A unique CD ROM for the true audio lover containing no fewer than 75 audio designs from the past five year volumes of Elektor Elec
32. This is microscopic compared to modern hard drives in PCs which can easily be 100 000 times as big It s therefore not possible to add many programs if you just make use of the Flash memory Luckily there is a way round this prob lem When you connect a USB drive to the just added USB port of the router the router can use this as a hard drive If this USB drive is a card reader or a USB memory stick the resulting server will be smaller than a lunch box On this server it should be possible to install all applications that can be installed on a normal server On top of this when you use Samba Windows Network access for Linux the USB drives can be made accessible to everybody on the network without having a power hungry PC on day and night The router can also function as a web server The files required to implement this can be found on our website at www elektor electronics co uk click on Magazine then underneath Archive click on the arrow next to the year and choose the required month With the right pro grams and hardware it is even possi ble to build domotica projects This will be covered in the next instalment 050360 I 1 www norocketscience com router 2 http midge vlad org va wiki Jeroen Domburg is currently study ing electronic engineering at the Saxion University in Enschede The Netherlands He is an enthusi astic hobbyist who spends much of his spare time on microcon trol
33. V to prevent the turns ratio of the transformer from being too high That saves quite a few turns on the secondary side The pri mary winding requires two sets of 12 turns and the secondary requires a total of two times 75 turns We decided to ground the centre of the secondary Winding so the voltage between the ends of the secondary winding and ground is only 500 V That keeps the maximum volt age between the primary and secondary windings within reasonable limits Of course you re free to wind the second ary as a single winding so it floats with respect to ground If you do that it s a good idea to double the insulation between the primary and the secondary To keep the electronics relatively sim ple the transformer has two identical primary windings so it can be driven in push pull mode That s easy to do with a toroidal core transformer by using a bifilar winding two wires in parallel The details of the transformer construction are described further on in this article The push pull configu ration allows the transformer to pro vide the maximum amount of power that is possible with the selected core 61 JACOB S LADDER see text 050192 11 Figure 1 Except for the fast diodes and the transformer the circuit is built using standard components In practice the centre tap of the pri mary winding is connected to the pos itive supply voltage Each of the other two ends is alternately co
34. We regret that no cheques can be accepted from customers or subscribers in any other country Giro transfer into account no 34 152 3801 held by Elektor Electronics Publishing Segment b v Please do not send giro transfer deposit forms directly to us but instead use the National Giro postage paid envelope and send it to your National Giro Centre Credit card VISA Access MasterCard JCBCard and Switch cards can be processed by mail email web fax and telephone Online ordering through our website is SSL protected for your security COMPONENTS Components for projects appearing in Elektor Electronics are usually available from certain advertisers in this magazine If difficulties in the supply of components are envisaged a source will normally be advised in the article Note however that the source s given is are not exclusive TERMS OF BUSINESS Delivery Although every effort will be made to dispatch your order within 2 3 weeks from receipt of your instructions we can not guarantee this time scale for all orders Returns Faulty goods or goods sent in error may be returned for replacement or refund but not before obtaining our consent All goods returned should be packed securely in a padded bag or box enclosing a covering letter stating the dispatch note number If the goods are returned because of a mistake on our part we will refund the return postage Damaged goods Claims for damaged goods must be received at our Brentford of
35. a DVD to transfer from Orcad Cadstar and Eagle Surprised it was missed Great magazine Bernard Gill Canada Well Bernard Microcad the mak ers of Wingcad were duly con tacted but unfortunately did not grant us permission to include their product on the Kaleido scope DVD It looks like Wing cad missed an opportunity not Elektor Free Electronics CAD tools DVD 4 Dear Sir Having been an ardent fan of your excellent magazine for a good many years now I think about 28 anyway it was before Junior Computer cannot remem ber ever having been disap pointed with any of your arti cles or features in the maga zine until now have recently developed an interest in CAD and have been trying to get started so when you advertised last month the free DVD with vari ous E CAD programs on it thought what an good way to evaluate and gain a little bit more knowledge on the subject So eagerly awaited the November 2005 issue as with most issues really load but as ever at times like these the ubiquitous comput er fairy waved her magic wand and nothing hap pened much to my disap pointment have tried the DVD on a friend s machine with exactly the same results so it appears that the Gods are not with me this time and think they are trying to tell me something Keep up the excellent work the E blocks looks very prom ising and will be definitely looking further into t
36. an odd smell and there s your basic fuse These suitcases reportedly were made between 1960 and 1965 and the one that s complete and in new condition must be priceless Maybe one day it will make it to Floglt 065008 1 Retronics is a monthly column covering vintage electronics including legendary Elektor designs Contributions suggestions and requests are welcomed please send an email to editor elektor electronics co uk subject Retronics EE 2 2006 elektor electronics Thie eoue BRUSHLESS MOTORS in practice Next Issue FREE BOOKLET e Short Course C for Microcontrollers Want to know everything each month o Select your own annual subscription and vee receive a free 1W Luxeon LED Torchlight Available options e Elektor Electronics annual subscription standard You receive 11 issues including the July August double issue e Elektor Electronics annual subscription PLUS You receive 11 issues including the July August double issue plus a copy of the Elektor Electronics Volume 2005 CD ROM e kt O r normal price 16 25 Your saving approx 10 00 fl t E n Please fill out the Order Form with this issue ron I CS Subscription rates and conditions may be found at the back of this issue Hexadoku Puzzle with an electronic touch Judging from the large number of correct solutions we received by email and regular post our new Hexadoku puzzle launched in last Janu ary
37. and will be forced into high state The AVD Auxiliary Voltage Detector detector of low voltage on the micro power supply will generate an interrupt which will immediately cut off the power stage if the power sup ply drops below 4 75 V in order to gua rantee at a minimum the power sup ply for the servos and receiver This is only temporary and the power stage will be operational again as soon as adjustable phase advancing At E a i 4 E j phase 3 T3 T6 ee oe en See sampling zero crossing commutation F f zi i Fia i r i Eid tal k 1 H external reference 050157 18 Figure 7 Sampling during ON time 26 the power supply is brought back up to a minimum of 5 3 V or the program med BEC cut off voltage which is necessarily superior or at least equal to 6 V for two Li Po or six NiMH cells It may be time to think about putting down your model Also note that sud den power stage cutoffs are either the sign that the batteries are reaching the end of their lifespan and can no longer supply the current required and that the voltage will drop dramatically or that defective servos are drawing too much current from the regulators For the rest we have six independent control signals for the MOSFET gate commands MCO0 to MCOB5 pins 10 to 12 are inputs enabling the sampling of signals relative to the detection of zero crossing events Two sampling mode
38. and will operate with all Professional versions of Flowcode 065030 1 o Earlier in this series Electronic Building Blocks November 2005 E blocks and Flowcode December 2005 E blocks in Cyberspace January 2006 Articles may be downloaded individually from our website Two offers you CAN t resist This month as a special offer to encourage you to investi gate CAN we are making available an Easy CAN Kit consisting of e Two PlCmicro Multiprogrammers with USB cables e Two 16F877A PlCmicro microcontrollers e Two CAN boards e One Switch board e One LED board e Two LCD boards e Flowcode 2 1 Pro version For a discounted price of 299 00 or 449 00 Also to support last month s article on using embedded microcontrollers to develop web pages we are making an Easy Embedded Internet kit available which includes e PlCmicro Multiprogrammer with USB cable e One 16F877A PlCmicro microcontroller e One Internet board with crossover cable e One Switch board e One LED board e One LCD board e Flowcode 2 1 Pro version For a discounted price of 232 50 or 349 00 Further details also on other E blocks may be found in the E blocks department of our website SHOP at www elektor electronics co uk elektor electronics 2 2006 E blocks Easy Internet Kit Connect your blocks to the internet E blocks are small self contained electronic circuits and printed circuit boards that
39. are used Figure 15 To be able to start the motor up and keep it running at least three half bridges are required The three outputs go to the motor windings which can be arranged in a delta or in a star configuration Figure 16 Battery 7 Ground 050321 19 Figure 15 Simplified three phase bridge drive circuit The control electronics ensures that two switches in the same column are never on simultaneously 2 2006 elektor electronics of 288 V from which a central inverter generates appro priate voltages for the motors Each cell has a capacity of 6 5 Ah giving a total stored energy at 288 V of 1 87 kWh The battery can deliver a power of 45 kW The current trend towards hybrid technology not only has the benefit of saving energy and reducing CO emis sions it also means that electric drives in larger cars can be tested and refined without using revolutionary battery technology If at some point a suitable power source such as the fuel cell becomes available to allow a purely electric drive system to be built the relevant motor technology will already be mature The hybrid concept will take another step forward when lithium based batter ies which are considerably more powerful than their nickel based counterparts are used in cars Here again model aircraft builders are already one step ahead 050321 1 The three windings are connected to the DC supply in turn so creating a rotating magnetic field that dra
40. can be combined to create functioning electronic applications and systems With the E blocks In ternet board you can connect your own system to the Internet This module is perfect to quickly add asimple webpage to your embedded system This then permits measu rement data to be inspected remotely Applications include reading out a weather station switching lighting systems and monitoring and controlling machines The application area is truly spectacular E blocks Easy Internet Kit Flowcode Professional 118 00 E blocks LED board 14 65 E blocks LCD board 19 30 E blocks USB Multiprogrammer 30 E blocks switch board 14 65 E blocks internet board e7195 PIC16F877 e 10 50 Ethernet crossover cable 15810 Total value 331 65 Special Offer 232 50 Learn more about E blocks For more information visit www elektor electronics co uk eblocks E blocks Easy CAN Kit A complex system made transparent The CAN bus is a resilient high data rate bus for communicating between electronic devices in situations where high data reliability is required One use of the CAN bus is in the automotive industry where it is being used as a substitute for copper wiring looms in cars The E blocks Easy CAN Kit allows you to employ this professional bus system in your own applications Implementing CAN is a complex task in languages like C but doing so with Flowcode and E blocks is actually very simple As a special offe
41. comment sign to render them ineffective Of course you won t be able to use a LED any more to check the signals but an oscilloscope will show a high frequency square wave signal Each time you modify the and kernel developers i What ere of darea protection mad pou ka i Praat bie BTN I jrin Nore The urm wall makin no nfiengd fr piolet the drew All Cao Hal oo ahaha Weel breed ofl patsy veal aa ihe caki Festa seten Abteecten Figure 8 Readout protection is unnecessary 2 2006 elektor electronics 43 050179 2 20 Figure 9 Connecting a LED to P1_0 cm05 0 Xin on cml6 0 Main clock No division mode cm17 0 cm06 0 CM16 and CM17 enable asm nop Waiting for stable oscillation asm nop asm nop asm nop ocd2 0 Main clock change prc0 0 Protect on The above listing shows the relevant instruction lines at the beginning of the source code It s necessary to change a few control bits in System Clock Control Registers 0 and 1 but they are initially in protected mode This protection is disabled in the first line so the relevant control bits can be altered After the bits have been MICROCONTROLLERS 050179 2 21 Figure 10 Connecting a loudspeaker to the microcontroller switched we have to wait a little while for the oscillator to stabilise after being started up After this the
42. credit debit cards Make cheques PO s payable oc Cali now for our FREE CATALOGUE with details of over 300 kits ETE projects modules and publications Discounts for bulk quantities oon Web wer QuasaElectronics com QUASAR Q871 Here are just a few of our controller and driver modules for AC DC unipotar bipolar stepper motors and servo motors See wesete for full T duini Bidirectional OC Motor Controller Controls the speed of most common DC motors rated up to a2 Vde SA in both the forward and reverse direction The range of control is from fully OFF to fully ON in both directions The direction and speed are con trolled using a single potentiometer Screw terminal block for connections Kit Order Code 3166KT 74 96 Assembled Order Code AS3166 23 96 DC Motor Speed Controller 6A 100V Control the speed of almost any common DC motor rated up to TOOV SA Pulse width modulation output for maximum motor torque at all speeds Supply 15Vde Box supplied Dimensions mm 6OVie1 OOLZ60H Kit Order Code 3067KT 11 96 Assembled Order Code AS3067 19 96 PC Standalone ee Stepper Motor Driver Drives any 5 6 or 8 lead unipolar stepper motor rated up to 6 Amps max Provides speed and direc tion control Operates in stand alone or PC controlled mode Up to sie 3179 driver boards can be connected to a single parallel port Supply 9Vde PCB 80x50mm Kit Order Code 3179KT 11 96
43. current pushes open contacts 4 and 5 to prevent the battery discharging into the dynamo A 21st century alternative Figure 2 shows our contact less semi conductor replacement for the pre war vibrating regulator A MOSFET is used to switch the field winding to ground instead of the regulator contact Elec tronic regulation means that we can dispense with the second regulation stage and 6 Q resistor in series with the field coil The field current through T1 is controlled by IC1 a micropower comparator type MAX921 which con tains a voltage reference source see Figure 3 The comparator is perma nently connected to the battery via connection 51 of the bikes wiring so it was important to use this IC for mini mum quiescent current The lion s share of this quiescent cur rent flows through D1 D2 and the volt age divider formed by R1 and R2 The zener voltage of D2 5 1 V approx together with the voltage drop across D1 0 6 V approx should be fairly close to the 6 V battery voltage in order to keep the quiescent current to a mini mum With a 6 V battery the quiescent current for the entire circuit is less than 250 UA to put this figure in per spective it is less than the battery s self discharge current i e even with nothing connected more charge leaks away through internal losses in the battery than this circuit requires Cur rent through the voltage divider chain increases proportionally once the dynamo output voltag
44. demos and more information on purchasing the XGS Pico and Micro Editions 067016 4 13 WTO AOTC NEWS amp NEW PRODUCTS New 16 bit XAP4 processor core Cambridge Consultants has released a new 16 bit RISC microprocessor IP core which it will feature at the Design amp Reuse IP SoC conference in Grenoble France on December 7th and 8th 2005 The all new 16 bit XAP4 features a modern high performance RISC architecture with low gate count low power consumption and high code density It is opti mized for use in cost and per formance sensitive ASIC designs and is available for evaluation now On a 0 18 micron CMOS fabrication process XAP4 can deliver up to 63 Dhrystone MIPS at a clock frequency of 117 MHz This benchmark perform ance of 0 54 MIPS MHz is a 50 improvement over Cam bridge Consultants previous 16 bit processor XAP2 which has been manufactured in hundreds of millions by licensees such as CSR and in ZigBee radios auto motive devices and low power industrial and medical sensors The XAP4 has both 16 bit data and address buses and is capable of running programs up to 64 kBytes The first implementation of the processor has a two stage pipelined Von Neumann architec ture It is delivered to licensees as a soft IP core in Verilog RTL that can be synthesized in as few as 12k gates for ASICs where die size and power consumption must be as small as possible Cambridge Consultants has already deliv
45. number using a DTMF phone from a anywhere in the world and remotely turn on off any of the 4 relays as desired User settable Security Password Anti Tamper Rings to Answer Auto Hang up and Lockout Includes plastic case Not BT ap proved 130x110x30mm Power 12Wde Kit Order Code 3140KT 39 96 Assembled Order Code AS53140 69 96 Serial Isolated 1 O Module Computer controlled channel relay board C SA mains rated relay outputs 4 isolated my digital inputs Useful in E a variety of control and Sensing applications Controlled via serial port for programming using our new Win dows interface terminal emulator or batch files Includes plastic case 130x100x30mm Power Supply 12Vde S00mA Kit Order Code 3108KT 49 96 Assembled Order Code AS3108 69 96 Lm T Ti 7417 714168 Infrared RC Relay Board gma Individually control 12 onm E board relays with included infrared remote control unit Toggle or momentary 15m range 112x122mm Supply 12Vdo 0 5A Kit Order Code 3142KT 39 96 Assembled Order Code AS3142 49 96 We have a wide range of low cost PIC and ATMEL Programmers Complete range and documentation available from our web site Accessories Programmer 40 pin Wide ZIF socket ZIF40W 16 00 18Vde Power supply P3U010 19 95 Leads Parallel LDC 136 4 96 Serial LDC441 4 96 USB LDC644 2 95 USB All Flash PIC a USB PIC progra
46. obliged to use prices and send the order form to Old Colony Sound Lab P O Box 876 Peterborough Date 2006 Signature NH 03458 0876 Tel 603 924 6371 924 6526 Fax 603 924 9467 EL02 Email custserv audioXpress com 7 Ce RRRRRRRRRRRERRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRERR Tel Email METHOD OF PAYMENT see reverse before ticking as appropriate Yes I am taking out an annual subscription to elektor electronics and receive a free 1 W Luxeon LED Torchlight Bank transfer Cheque UK resident customers ONLY Giro transfer Visa F a would like Standard Subscription 11 issues Subscription Plus 11 issues plus the Elektor Volume 2005 CD ROM Ae A AP dae T ET T Offer available to Subscribers who have not held a subscription to Elektor Electronics during the last 12 months Offer subject to availability See reverse for rates and conditions Verification code paaano goo aoan oA Onoon SWITCH ONLY Stare daters A a A E EE AE cee Name Bsuenumbek rs ere ee eee ea Address Post code Please send this order form to Elektor Electronics Publishing Regus Brentford 1000 Great West Road Tl o S a Emi Brentford TW8 SHH United Kingdom haw kl d gt Tat an G3 Date 2006 Signature Tel 44 0 208 261 4509 cross out what is not applicable Fax 44
47. of what manufacturers offer today in the field of Home Networking both wired and wireless New The CD ROM contains specifications standards and protocols of commercially available bus and network systems For developers there are datasheets of specific components and various items with application data End users and hobbyists will find ready made applications that can be used immediately The documents included on the CD ROM have been classified according to communication media mains power line coaxial cable telephone line and wireless RF ISBN 90 5381 195 8 All about l Home Automation Subscriptions Elektor Electronics Publishing Regus Brentford 1000 Great West Road Brentford TW8 9HH England Tel 44 0 208 261 4509 fax 44 0 208 261 4447 Internet www elektor electronics co uk Email subscriptions elektor electronics co uk Rates and terms are given on the Subscription Order Form Head Office Segment b v PO Box 75 NL 6190 AB Beek The Netherlands Telephone 31 46 4389444 Fax 31 46 437016 Distribution Seymour 86 Newman Street London WIP 3LD England UK Advertising Huson International Media Cambridge House Gogmore Lane Chertsey Surrey KT 16 9AP England Telephone 44 0 1932 564999 Fax 44 0 932 564998 Email relgar husonmedia com Internet www husonmedia com Advertising rates and terms available on request International Advertising Klaas Caldenhoven address as
48. patience waiting for respons es from the old server partic ularly between 15 November and 4 December 2005 and hope they have not been inconvenienced too much The new server has been online since 5 December 2006 with good results In our online Forum freely accessible to all readers a new topic folder has been created for the SMD Reflow Oven project from our January 2006 issue which is generating great interest We would certainly like to hear of your experi ences in converting your own oven As of the January 2006 issue Mailbox can be downloaded free of charge as a pdf file This may include material belong ing with Rejektor items that could not be fitted in the magazine Free Electronics CAD tools DVD 3 Dear Editor purchased last month s issue November 2004 Ed because of the review of PCB software One package missing from the DVD is Wingcad As your lead article suggest ed took the batteries out of the door bell unplugged the phone had some cans of lager to hand packed the wife of to the mother in law gave the kids some money to go out with then got down to some serious eval www wing vation cad com inserted the They have CAD Software DVD into a huge for electronics the user drive base then e Schematics with N PCB Design Simulation S Ena ns baw bated lektor breath Canada lektuur waited and have ae for the reasonable
49. power are required such as in hybrid drive cars and in electric model aircraft A special place is occupied by LRK motors which fulfil the requirements of modellers for directly driving as large a propeller as possible They fea ture a very simple and therefore economical construction a free running rotor with normally 14 magnets ten mag nets is also possible encloses a 12 part stator A special winding technique is used called separated phase sec tors or SPS here each phase is assigned to a separate sector This guarantees a very close magnetic coupling between the two magnetic systems and a high speed reduction ratio and correspondingly high torque Drives of the future Power electronics and modern magnetic materials have brought about radical but practically unnoticed changes elektor electronics 2 2006 in electric motor technology what one might call a quiet revolution In many applications brushless electric motors deliver better power to weight ratio than fuel oowered engines In automotive drive systems we are only now learning how to take advantage of the enormous torque that electric motors can provide practically independent of speed as featured in high performance hybrid vehi cles such as the Lexus RX 400h The main electric motor in this large car delivers 123 kW 167 bhp with a torque of 333 Newton metres A second electric motor driving only the rear axle provides a further 50 kW 68 bhp with a
50. s issue has met with great interest The puzzle also appears to be well liked by family members and friends of the electronics fans buying Elektor or subscribing to it probably because of the extra challenge posed by the hexadecimal number series lej2 sf Ipi fs lafe 3 4j2 p5lajojejE 7 8 7e D9 slat fot LT Is NO CECE sr 21 e seta lal ci3i7 2 Joj s ciBi3 Jel7je f8 l lel JE 7 Jpicjo J5 a D c Jef 2 Je le Bi3fo s 7lo Fle 4 El fsfe sla l5jc D 14 je s la l OO y Elektor s new brainteaser for the electronics enthusiast and keen reader of the magazine appeared to be fairly difficult to solve Many readers report having spent quite a few hours completing the thing and were happy to rise to the 2 2006 elektor electronics challenge The instructions for the puzzle are straightforward In the diagram composed of 16x16 boxes enter numbers in such a way that all hexadecimal numbers O through F that s O 9 and A F occur once in every row once in every col umn and in every one of the 4x4 boxes marked by the thicker black lines A number of clues are given in the puz zle and these determine the start situation Your solution may win a prize PUZZLE INFOTAINMENT Entering the competition Please send the numbers in the grey boxes by email fax or post to Elektor Electronics Hexadoku Regus Brentford
51. so ECK3D562KBP Digi Key P9574 ND Semiconductors D1 D20 DSA 1 18D 1800 V 7 A IXYS Digi Key DSA1 18D ND 4019373 9 8 oO oO Z Z6LOSO Oo Oo O O O 4019313 9 Z Z6LOSO O O O O hse you can use types other than the IXYS type DSA 1 18D that we used 1800 V 7 A Besides the relatively common TO220 types you can also use SMD types in an SMB package such as the STTH112 We first tried the latter type of diode in a cascade with somewhat smaller capacitor values However we found that it gave up the ghost fairly often during our experiments It s pos sible to find diodes that can handle rel atively high voltages such as the SM6500 series from VMI but they are difficult to obtain During our experiments it became apparent that the impedance of a cas cade of ten diode capacitor pairs is especially high We thus decided to use 5600 pF capacitors instead of the 1800 pF types we were using up to then Both types come from the Pana sonic line of high voltage ceramic disc capacitors which are characterised by low losses and are specifically intended to be used in switching appli cations with high voltages We select a series with a working voltage of 2 kV in order to avoid any problems from the spikes at the output of the transformer Miscellaneous PCB ref 050192 2 from The PCBShop Figure 6 The two circuit boards for the cascade stages are nearly the same The only difference between the two is
52. software AGC S meter spectrum readout and various demodulators all of which provide great enhance ments to the receiver 050395 1 75 DESIGN TIPS Digital sinewave reference generator IC3 TLO62 IC3 AT90S1200 Martin Ossmann When it comes to testing and measuring audio circuitry a very clean and stable 1 kHz signal is often required The Wien Bridge has been the preferred circuit con figuration for many years In the digital age however there are alternative means available A low cost microcontroller drives a D A converter whose output sig nal is filtered using a bandpass in order to suppress alias frequen cies This setup guarantees an output signal that s spectrally pure as well as stable in respect of amplitude and frequency everything you would like to have for spotfrequency measurements PBO PB1 PB2 PB3 PB4 Figure 1 shows the way the above concept has been turned into a practical circuit The 16 bit D A converter is remarkably cheap at less than 80 p from Reichelt Germany which helps to keep the cost of the circuit as low as possible Microcontroller IC1 generates 74 samples in 12S format in every 1 kHz period This creates a sampling rate of 74 kHz much higher than your average CD player The two cur rent outputs of the DAC IC2 have been connected in parallel to maximize the signal to noise ratio The first opamp of the TLO62 acts as a currentto voltage converter The seco
53. software CD ROM at a very attractive price We already introduced the Renesas R8C in the last issue Now it s time to start using it Now it s for real from this issue you can order a circuit board with an R8C 13 microcontroller and the neces sary software at price consisting of P amp P and handling only The service is strictly limited to stocks and pro vided exclusively for Elektor Electron ics readers in co operation with Glyn So if you want to grab an R8C starter kit order it straight away the online 38 method using our website is by far the fastest There are three good reasons for using the Renesas R8C Tiny family first it provides 16 bit computing power at a low price second it comes with a free but nevertheless very capable C com piler and third no programming hard ware is necessary because code can be easily downloaded to flash mem ory via the RS232 port We already introduced the board and the soft ware in the January 2006 issue If you missed that article you can download it free of charge from the Elektor Elec tronics website at www elektor elec tronics co uk select the Magazine tab then January 2006 Our objective in this article is to help you start using the board elektor electronics 2 2006 The software When installing the nec essary software follow Configure AutoUpdate the instructions exactly as n given in order to ensure Srherduing l that what you later see
54. speeds travelling wave motors can develop relatively high torque and a gearbox is often unneces sary An alternative to this type of motor with rotating bending mode waves is to use a stator with thickness extension mode oscillations in yet another design a bending mode wave is set up in a cylindrical stator Usu ally microcontrollers are used for control with a power output stage and possibly also a transformer to further increase the output voltage One application for such travelling wave ultrasound motors is in autofocus lenses To produce a sharp picture the individual elements of the lens must be moved together usually on a worm ype drive Since great agility is required but the distances involved are relatively short the situation is ideal for a piezoelectric motor Applications for piezoelectric motors are not yet exhausted provided their power can be increased further They will shortly be used in aviation for moving aircraft control surfaces and in robotics There is no technical reason why they could not also be used in such general purpose applications as windscreen wiper motors or elec tric windows but here the mass produced conventional motor still have the upper hand in terms of mass produc tion costs 050375 1 2 2006 elektor electronics App lications of the direct and the inverse piezo effect Direct piezo effect pressure to voltage Sensors for pressure and acceleration Keyboards Pick up a
55. supply protection etc The audio signal goes to an input buffer first and is then combined in a pi style regulator with the feedback signal from the output stage The signal then continues on to two comparators operating in anti phase which compare the volt age with the signal from the triangle generator The comparators supply the PWM signal that is used to drive the final stage The final stage consists of a bridge of four power FETs The loud speaker is connected between the FETs via an output filter A special H bridge IC from Intersil provides the 51 GOR AMPLIFIERS gate drive for the FETs In addition to generating the correct drive signals the IC also inserts a brief dead time at the switching edges to prevent the two series connected FETs from conducting at the same time during the transition This is the whirlwind overview of the design Complete schematics and a detailed description are available from the designers own website www wictronic ch First measurements According to the accompanying tech nical specifications the distortion from the amplifier would amount to 0 05 THD and that sure is a very good value for a class D amplifier We were therefore curious what the outcome of our own measurements would be So we went to work in the Elektor Elec tronics lab with our Audio Precision System Two analyser The first measurement was to deter mine the distortion of one half of the bridge
56. taken further to six eight or even ten poles distributed around the rotor with a corresponding gearing down effect The paths of the magnetic flux are also shorter running from a north pole to an adjacent rather than an opposite south pole The enclosure com pleting the magnetic circuit can then be made thinner thus reducing the total weight of the motor An interesting development in this direction is the Tango modellers motor from Kontronik The 6 pole rotor Fig ure 10 is surrounded by an iron free self supporting coil as stator This is enclosed in a thin walled iron cylinder which completes the magnetic circuit The novel feature is that this cylinder is mechanically linked to the rotor and turns with it There is thus no relative motion between the magnetic field and the iron minimising speed dependent losses This is a brushless variation on the ironless core motor which thanks to the use of six poles offers formi dable torque see Figure 11 External rotors Of course there are limits to the number of poles that can be used As the magnets get smaller the windings also have to be split into more and more segments In itself this does not cause any great problems but it turns out that as the poles of the magnets are sited closer and closer together efficiency falls off This is because part of the flux finds its way to a neighbouring pole without pass ing through the stator As a result the gearing relation
57. wrong with the amplifier Was there a fault in the design or was something else the matter This turned out to be quite a quest H Brid ith Problems Pl Controller HIVA Differential Input Analog Inverter T IMeg C408 11V_A 100nF R403 se s C 47k from Sheet 1 AGND q TP402 C diff Out AGND AGND AGND AGND TP407 Feedback Right PWM Bus from Current Limiter Disable from Sheet 2 HIP4082IB T400 T402 SI7852DP SI7852DP to Current Limiter TEINS R434 SHUNT 22m 1W to Sheet 2 PGND PGND Ton Giesberts Design Stefan Wicki Comparator TIND UAA Right PWM Bus LM319D R423 TP405 k BL 560 C432 100pF PGND PGND Output Filter L400 15uH 5 5A L402 4 7uH 5 5A C421 2 2uF 100V C423 433 0 47uF 100V TAW PGND PGND Speaker Out Right C425 L401 68nF 100V 15uH 5 5A L403 4 70H 5 5A ut R C422 C424 2 2uF 100V 0 47uF 100V PGND PGND 050183 11 Figure 1 One channel of the CDAMP designed by Mr Wicki a and the accompanying triangle generator b First impressions looked so promising The Swiss lecturer in electronics Mr Stefan Wicki offered us a design for a power amplifier the CDAMP that he had developed and uses as a construction project for his stu dents at the University of Applied Sciences in Aargau The schematics and photos looked very promising and the prototype in a v
58. 12lb 5kg heavier parcels POA Minimum order 20 wre a WIZARDS OF Now that we are not the cricket wizards anymore we ve reverted back to our trusty soldering irons Call or log on to our website and apply for a FREE 400 page catalogue You can purchase on the Net from us 24 7 365 through our secure encrypted system Post and packing charges are modest and you can have any of 8000 unique products delivered to your door within 7 10 days of your order High Performance Electronic Projects for Cars Australia s leading electronics magazine Silicon Chip has developed a range of projects for performance cars There are 16 projects in total ranging from devices for remapping fuel curves to nitrous controllers The book includes all instructions components lists color pictures and circuit layouts There are also chapters on engine management advanced systems and DIY modifications Over 150 pages All the Clock Watcher s LED Clock Kits KC 5416 blue 55 25 post amp packing KC 5404 red 41 75 post amp packing These clocks are hypnotic They consist of an AVR driven clock circuit that also produces a dazzling display with the 60 LEDs around the perimeter It looks amazing but can t be properly explained here We have filmed it in action so you can see for yourself on our website www jaycarelectonics com Kit supplied with double sided silkcreened plated through hole P
59. 5 mm to be fitted In some case only 5 mm devices can be accommodated and this is expressly stated in the parts list The third group is formed by electrolytic capacitors with val ues generally below 1 uF Here the tolerances are huge of the order of 20 to 50 The working voltage may be any thing between 3 and a couple of hundred volts In general an electrolytic capacitor does not require a higher voltage specifi cation than the circuit supply volt age this incidentally applies to all components Electrolytic caps come from tens of different sup pliers and their electrical prop erties may show up vast differ ences We attempt to design our circuits in such a way that nearly every type of modern electrolytic capacitor can be used One of the few exceptions are switch mode power supplies in which massive peak currents and high switching frequencies occur The high internal resistance of a bad electrolytic in a critical spot in an SMPSU causes ripple on the output voltage Plus the cap will run very hot and believe it or not there exist elec trolytics with a life expectancy of 1000 hours at 80 degrees C However these are exceptions and we will always provide an indication where special param eters are required As already mentioned we spec ify minimum values like 10 uF 10 V Your supplier may not have this particular device in stock offering you 10 uF 35V or 10 uF 63V instead Fi
60. CAN bus basics and show you how E blocks and Flowcode allow you to easily implement CAN CAN stands for Controller Area Network denoting an the low level software communication protocols international standard for serial communication used to Physically the CAN bus itself consists of a twisted pair of control devices on a network The CAN standard governs wires which use differential voltages for data transmission some of the physical attributes of the network as well as there is no earth ground wire in CAN and differen tial voltages make the system very immune to noise CAN is designed primarily for control and hence the messages used are small at just eight bytes maximum As illustrated in Figure 1 the basic message structure Message ID contains two parts a message identity and message data The actual structure is a little more complicated than this with error detection synchronization and other Figure 1 bits being embedded into each message However one Heavily simplified CAN 065030 11 of the great benefits of CAN is that the ICs used take data structure care of these details for you and provide you simply with message and data information Functional overview Figure 2 shows a typical CAN node on a network All nodes have a microcontroller with I O circuitry a CAN Microcontroller Eene controller and a line driver which interfaces the CAN L and CAN H differential connections to the CAN con troller Some microcont
61. CB and all board components as well as the special clock housing Available in Blue KC 5416 and Red KC 5404 High Range Adjustable J Temperature Switch with LCD KC 5376 22 75 post amp packing Heat can be a major problem with any car especially modified and performance cars The more power the more heat so you need to ensure you have adequate cooling systems in place This temperature switch can be set anywhere up to 2192 F so it is extremely versatile The relay can be used to trigger an extra thermo fan on an intercooler mount a sensor near your turbo manifold and trigger water spray cooling or a simple buzzer or light to warn you of a high temperature The LCD displays the temperature all the time which can easily be dash mounted Kole Kolaik o www jaycarelectronics co uk elektor for your FREE catalogue 0800 032 7241 Monday Friday 09 00 to 17 30 GMT 10 hours only For those who want to write 100 Silverwater Rd Silverwater NSW 2128 Sydney AUSTRALIA FI232R USB VART with MCU Clock Generator and FIDIChip ID Security Dong MORE Integration EEPROM internal clock generator and USB termination resistors on chip Functionality integrates the functions of USB UART MCU clock generator and Security Dongle into a single chip Flexibility five IO pins can each be user configured as Sleep Transmit Enable Power Enable MCU Clock Output TX RX LED Drive or GPIO Pin Security FTDICh
62. D l interfaces www atcsemitec co uk p See our webpage for more Thermal and current sensitive components details Only 29 99 inc vat for temperature control and circuit protection BETA LAYOUT e NTC Thermistors e Current Diodes e Thermostats e Re settable Fuses www pcb pool com e Thermal Fuses e Temperature Sensors Beta layout Ltd Award winning site in both English and German offers prototype i PCBs at a fraction of the cost a the usual manufacturer s prices BURN TECHNOLOGY LTD http www burntec com Test amp Measurement Equipment Distributors e Anemometers Clamp Meters e Light Meters LCR Meters e Sound Meters e Multimeters e Device Programmers Burn Technology Limited Winfrith Technology Centre Dorchester Dorset DT2 8DH Tel 01305 852090 Fax 01929 463214 COMPUCUT http www compucutters com Computer Numerical Control from your home PC Great for tricky jobs and accurate repetitive work We supply Software Interface Manual Support Price 250 plus postage COMPULOGIC LTD www compulogic co uk Internet Remote Control Starter Kit 139 99 Create a simple web based remote control interface for many applications e Miniature Web Server Module e Analogue Digital Module e PSU ET e Manuals software example HTML code CONFORD ELECTRONICS http www confordelec co uk Lightweight portable battery mains audio units offering the highest technical
63. DE IES Buta S T36 pa 13 Oe z fi ere ye et oie T39 738 gt re c12 ios a3 Parle zo EEE aoo0oo0oo0o0 Figure 10 The double sided board of the power stage 28 example We can then operate the motor control cell of the micro to its utmost and utilise synchronous rectifi cation How about that Synchronous rectification Figure 9 shows what happens in a bridge branch when the PWM signal is applied to the P MOSFET When the g0o0000 0K c10 050152 241952 me IEIR a L Figure 11 The double sided board of the control module PWM is ON closed switch the cur rent thus passes through the top MOS FET to go into one of the motor phases When the PWM is OFF open switch the current continuous to the coil ter minals must make a path via the bot tom transistor in the same bridge branch If the bottom MOSFET is OFF this current shall pass this way via the internal freewheeling diode poor diode quality in general A rise in temperature will result which is by the way the main reason a MOSFET stage would overheat in this type of application In summary why not uti lise the bottom MOSFET N when the top MOSFET P is OFF That is quite clearly the definition of synchronous rectification When the top P MOSFET is open the bottom N MOSFET closes after an adjustable time delay called dead time which is required to avoid any short circuit of the branch this time delay has been set
64. F Please save deliver one copy of Elektor Electronics magazine for me each month lectronics Name leading the way Address Please cut out or photocopy this form com Post code plete details and hand to your newsagent Telephone Elektor Electronics is published on the third Date Friday of each month except in July Signature Distribution S O R by Seymour NS www elektor electronics co uk All magazine articles back to volume 2000 are available online in pdf format The article summary and parts list if applicable can be instantly viewed to help you positively identify an article Article related items are also shown including sofware downloads cir cuit boards programmed ICs and corrections and updates if applicable Complete magazine issues may also be downloaded In the Elektor Electronics Shop you ll find all other products sold by the pub lishers like CD ROMs kits and books A powerful search function allows you to search for items and references across the entire website Also on the Elektor Electronics website e Electronics news and Elektor announcements Readers Forum e PCB software and e magazine downloads Surveys and polls e FAQ Author Guidelines and Contact 84 elektor electronics 2 2006 Please supply the following For PCBs front panel foils EPROMs PALs GALs microcontrollers and diskettes state the part number and description for books state the full title for photocopi
65. Figure 8 Construction of a two pole motor with air gap winding Figure 9 Diagram of a slot wound four pole motor Figure 10 Pseudo iron free Tango motor with a six pole rotor Figure 11 The speed torque and efficiency of the motor of Figure 10 depend on the motor current 19 Figure 12 The distance between the magnets in a multi pole machine in this case with exterior rotor should not be too small Right a ten pole rotor where one pole is formed by each group of three adjacent magnetic strips Figure 13 Diagram of a brushless motor with exterior rotor Figure 14 Brushless motor with exterior rotor designed for use in models 20 DC MOTORS Back iron 050321 18 than their diameter This gives improved efficiency greater than 90 and power to weight ratio More poles Greater torque is of course desirable One tried and tested method is to increase the number of magnet poles in conventional technology using brushes this was sim ply too complicated to achieve A four pole motor Fig ure 9 has a magnet pole every 90 degrees alternating north and south This functions as if there were two motors in one enclosure This halves the speed of the motor as one transition from north to south and back cor responds to only half a revolution The torque however is multiplied by four Sometimes we speak of an electri cal 2 1 reduction gearing This idea can be
66. K Johnson UK LEi all Pe amp a a oe ra r E E E E _ E E 1 is m 1 s A m A We not only know the error report we also have the solution to the problem From the directory c winnt repair copy the file autoexec nt and paste it into the winnt system32 directory i e Xmas Special edition 1 Dear Editor have just received the December 2005 edition of Elektor Electronics magazine and the articles make as usual very interest ing reading However am disap pointed Your previous December issues carried the Xmas Special 30 circuits and design ideas for the Xmas holidays These are missing this year and feel you have let us down hope to see them again in next year s Xmas edition Ken Barry UK Xmas Special edition 2 Dear Jan what happened to the circuit supplement in the December issue always looked forward to these idea provoking small projects was disappointed to find the supplement miss ing from the December issue after 15 years with no explanation or statement that the feature had been suspended As a result of this the mag azine seemed a bit thin for articles do not expect every issue to be full of arti cles or projects that are of interest to me if that were so would not have been a subscriber since 1978 Generally Elektor does very well to provide a varied mix of interesting and useful arti cles and pr
67. MOS FET despite a higher frequency that does not change a lot because we are using synchronous rectification The curious among you can connect a volt meter oscilloscope in frequency meter mode to pin PAS of the microcontroller the TTL signal is at a frequency iden tical to the electrical frequency of the motor Knowing the number of pole pairs allows us to immediately deduce the timing of the motor reminder motor timing RPM 60 Fale num ber of pole pairs One last point that we have not yet stressed when star ting with a cold motor start up always follows a linear acceleration ramp during which we force the motor to a i The author Florent Coste received his engineering degree in microelec tronics in 2000 from the Charles Fabry Institute in Marseilles France Since that time he has been employed as an applica tion and support engineer by STMicroelectronics and is based in Hong Kong Having specialised in microcontroller software he worked for two years in close collaboration with Asian clients to implement the multimedia platform Later he specialised in motor control applications which led him to develop projects based on micros specifically the STZMC to mention only the latest trendy ST micro dedicated to driving synchronous brushless air conditioned for example and asynchronous induction motors A big fan of aeromodelling and electronics Florent uses his knowledge in those two fields to f
68. MPUCUITEFS COM 6 6 ee 80 Compulogic Showcase WWW COMpUIOGIC CO UK 0 ee ce 80 Conford Electronics Showcase www confordelec CO UK 02 eens 80 Cricklewood se nw yews wean wa ace a www cricklewoodelectronics com 4845 Danbury Showcase www livinginthepast demon co uk 80 Design Gateway Showcase www design gat way cCOM 05000e 80 Eaglepics Showcase WWW aQGI PICS CO UK 6 ce ee 80 Easysync Showcase 2 e6 WWW eaSySync CO UK ca s kam 2 De Oe eas 7 80 Elnec Showcase WWW BIEL CONT gs oes toe ca eee hs oe eases 80 Eurocircuits 2 0 25228 o0 e05 cee bean ks www thepCbShOp cOM 00 cece ees 14 FOTEST ee anan es eee 20a oe moe ane www fored co Uk corte ceeed weaee sens 45 Future Technology Devices Showcase www ftd chip cOM 00 eee eee 3 80 Futurlec SHOWCASE 6c ecxdetaxcnmaes WWW TUONO GIGON 25225242 si 2b 402 Ke kia 80 Ipeva Limited Showcase WWWIDBVACOD os si 6 i402 eck sade en eantlos 80 Jaycar Electronics lt avecdenness oe www jaycarelectronicS CO UK 0055 2 JLB Electronics Showcase www jlbelectronicS COM cece eee 81 KMK Technologies Ltd Showcase WWW KMK COM NK 0 000 ccc ee ee 81 2 2006 elektor electronics Cabcenter sages saencse ceeesareane www labcenter co uk oo i3s cn dea Sees wien 88 Lichfield Elect
69. PN transistor inverts the TXD signal from the PC and feeds it to the RXD1 input of the microcon troller This input does not have an internal pull up so the collector resistor is essential In the opposite direction TXD1 drives a BC558C PNP transistor The RXD input of the PC has its own pull down so the collector resistor can be omitted here The MODE input of the microcon troller determines whether the inter nal boot program or a downloaded user program is run after a reset The MODE input is pulled high by a 10 kQ resistor when the switch is open which causes the user program to be started If you want to load a program into the flash memory you first have to close the switch in order to pull MODE low Then you must briefly press the Reset switch That causes the microcontroller to start up in the debug mode which allows new soft ware to be loaded into the flash ROM After the software has been trans ferred open the Mode switch and press the Reset switch again That causes the downloaded program to be started However duty comes before pleasure and in this case the duty is installing the software on the PC That s described step by step in the inset Follow the instructions exactly as given in order to ensure that what you later see on your PC matches what we describe here Ready set flash The first thing you should do is to try out the Flash Development Toolkit FDT by downloading a finished pro gram to th
70. Q for 41 MICROCONTROLLERS ADT Simplo iniotieces Wnainppertod Firomware Vorainn MASIE PILE Pa yo Device Pee Fie Sebeciein tee Arei Pont a Eb Cian Fide iai E lh ia e pea ete ieee pee ee e l a E pee amp hua a eee eee ere Figure 5 The Flash Development Toolkit Basic version example when connecting a LED to them Figure 9 All of the sample programs described below can be copied to the microcon troller in the manner just described If the R8C cannot be flashed due to a communication error it must be left without power for one minute to erase the internal RAM loader This error can occur if you have been working with the debugger before attempting to download a program The R8C as a musician Like to try another hardware test Chasan Devices And Karr Then download the Jingle Bells Motorola file from the R8C project to the microcontroller Connect a small 8 Q loudspeaker or a headphone with a 1 kQ series resistor to the board Fig ure 10 and then start the microcon troller You will hear a simple melody Incidentally this program uses the internal high speed ring oscillator 8 MHz and does not require the crys tal oscillator If you touch an oscillo scope probe to the crystal lead Xin pin 6 or Xout pin 4 you will see that no clock signal is present in contrast to the situation with the port toggle project As you can hear from the Pe FLASH Ceveogmernd To
71. R electronics SYTRONIC TECHNOLOGY LTD www m2mtelemetry com Supplier of wireless modules and accessories for remote monitoring M2M applications e GSM GPRS TCP IP modules e Embedded GSM GPRS modem e Development Kits e GPS modules e GSM GPS antennas e Adapter cables Online ordering facilities Tel 01394 210911 USB INSTRUMENTS http www usb instruments com USB Instruments specialises in PC based instrumentation products and software such as Oscilloscopes Data Loggers Logic Analaysers which interface to your PC via USB VIRTINS TECHNOLOGY www virtins com PC and Pocket PC based virtual instrument for electronics enthusiasts students professionals and scientists including sound card real time oscilloscope spectrum analyzer and signal generator Free to download and try ELECTRONIC ENTHUSIASTS Only one magazine tests its projects and circuits in its own lab before publication ELEKTOR ELECTRONICS THE ELECTRONICS amp Unit 4 Gibbs Reed Farm Pashley Road Ticehurst TN5 7HE Telephone 01580 200657 Fax 01580 200616 www elektor electronics co uk COMPUTER MAGAZINE SHOP More information on www elektor electronics co uk CD ROM BESTSELLERS Handbook for sound technicians ECD Edition 3 Elektors Components Database gives you easy access to design data for over 5 000 ICs more than 35 000 transistors FETs thyristors and triacs just under 25 000 diodes and
72. So the plot thickens In order to see exactly what was going on the amplifier was driven a little harder supplying 10 W into 4 Q see Figure 2 The scope now displayed the output signal getting stuck at around 20 V It appeared that there was clipping in the output stage but this could not be possible because the power supply voltage was set to 30 V Despite the clipping phenomenon the amplifier could be driven further to 50 W into 4 Q see Figure 3 In the waveform of Figure 3 there appears to be crossover distortion However we re dealing here with a class D amplifier here not with a class B output stage As a result of our DT S Oot Le Ca own TN A w F K daf NUA d ee Wa sow 19 ath uma b 19 a00 DH Hi Cacti Gi urnar a erste wH ll oe dt 1 000 mg at TOO0 000 Hz dt 1 000 mg H ww 1 9 ah gil g ma il 1a DH i Courae rel vie cm gi j z wic ii 3 gt Right Channel Pov Speaker Sup Chinch 4 Ohm 12VDC Input Output Ing gt WWW WIctronic ch PO A SOO a Te Oe Figure 2 At an output of 10 W into 4 Q the output signal gets stuck at about 20 V 52 Figure 3 At increased drive 50 W 4 Q a type of cross over distortion seems to occur elektor electronics 2 2006 ply S0VDBC ut Speaker 4 Ohm Output ei SOL LA HJ ures 1 9408 CH fy Seure 1 A ea Oe arc 1 000 Figure 4 The integrated control si
73. Z C ANSI Compiler and Rapid Application Development in C WIZ C is more than a C Compiler for the PIC it is a complete development environment with rapid access to library components with point and click set up A e Ideal for beginners includes full tutorial manuals and an introductory USB development Support Add on library provides point and click CDC support to WIZ C Installs as a virtual com port access easily from C Visual BASIC Hyperterminal etc e Development board pictured based on 18F 2550 supplied with bootloader and sample application See website for details manual to the C language e Syntax highlighting editor Full ANSI C Compiler e Large libraries included for displays ports data transfer keypads graphics bootloader and C standard functions e Extensive simulation capabilities very rapid program execution includes simulation of LCD LED switches 12C R5232 terminals etc Inspect C variables in C format e Logic analyser can display waveforms of PIC pins and internal registers simplifying debugging Includes assembler to allow you to develop assembler projects in their own right or as part of C projects LITE version supports the most popular PIC devices academic users may choose these types e UK written and supported Priced from 35 00 We accept major credit cards and Switch Order securely from our site www fored co uk or contact us by phone or fax on
74. age even for peo ple who are only used to working in assembly language The unfamiliar notation will quickly become second nature after you work through a few examples so there s no need to be afraid of C First copy the entire port toggle proj ect from the CD to your PC When you start a new project use a directory such as C WorkSpace which is also the default directory suggested by HEW In the Renesas program group start the High Performance Embed ded Workshop program A selection window is displayed when the pro gram starts and you can specify whether you want to generate a new project or open an existing project Use File Open Workspace to open the port toggle file All the files belonging to the project will then be shown at the left Click on port_toggle c to open the source code file Everything should then appear as shown in Figure 11 Next you should try to compile the project just for the exercise First you have to decide whether you want to generate a debug version or a release version You should work without the debugger for now which means you should select the Release option elektor electronics 2 2006 under Build Build Configurations Then start the compilation by select ing Build Build All The C source code will be compiled linked and written to the output directory Release in the form of a Motorola hex file The entire process is listed at the bottom of the Build windo
75. ah it blinks Now connect the board to the specified COM port on your PC Close the Mode switch and briefly press the Reset switch The microcontroller will enter boot mode and wait for you to send it data The next step is to download a fully compiled program to the microcon troller On the CD you will find the Sample NC30 folder with several sam ple projects That includes the project folder Sample NC30 port toggle which contains the folder port _toggle Release The file port _toggle mot is located in the latter folder It is a pro gram in Motorola hex format that can be downloaded directly to the micro controller Specify the path to this file and then start the download process by select ing Program Flash The download takes around two seconds The flash memory is first erased and the new program is then copied over If every thing goes properly the message Image successfully written to device will be displayed Open the Mode switch and briefly press the Reset switch That will start the program that you just downloaded The program toggles the first four lines of Port 1 P1_0 to P1 4 at a slow rate so you can observe their states using a LED with a series resistor The ports of the R8C and the other M16 microcontrollers have a low imped ance in the output direction regard less of whether they are in the high or low state That means you must always use a series resistor 1 K
76. ain con trolled amplifier regulates the receiver output voltage to a con stant level of about 100 mV The governing factor is the control loop time constant that prevents abrupt level changes The circuit is not only useful with DRM reception AM and SSB modes will also benefit from it In connection with the DRT1 the gain span is about 115 dB ensuring that the optimum gain is available at all times 050235 1 supplies a square wave at pin 5 that drives the loudspeaker The toggling voltage at the output of the first timer pin 9 causes elec trolytic capacitor C3 to be partly charged and dis charged periodically via resistor R3 C3 is connected to the con trol input of the sec ond timer pin 3 causing it to work as a VCO voltage con trolled amplifier The upshot is that the fre quency of the square wave applied to the loudspeaker rises and falls periodically ren dering a good imita tion of the wailing sound of the US police car siren we hear too often in movies The small number of dead standard compo nents used enables this circuit to be built on Veroboard without problems 050349 1 elektor electronics 2 2006 Parallel resistor calculations Ton Giesberts This design tip describes a simple equation to compose a desired resistance from two parallel con nected resistors The formula for parallel connec tion of two resistors may be found in any electronics textbook and reads
77. an only carry low currents if wear is to be kept within rea sonable limits which considerably restricts the range of possible applications of these motors A further disadvan tage is the radio frequency interference produced by the commutator which increases wear and entails the use suppression measures Figure 5 More sophisticated are the so called ironless core motors Figure 6 Here an iron free armature generally a self supporting coil potted with fibreglass cloth rotates around a central magnet The motor enclosure completes the magnetic circuit Since there is no iron rotating in the field iron losses are negligible and efficiencies of over 90 are possible These motors also offer relatively low torque since the magnetic flux has to span two air gaps and the thickness of the coil lronless core motors are generally powered via fine precious metal brushes Their advantage is their high efficiency albeit at low power and in particular the low inertia of the rotor They are therefore suitable where rapid response is required with continuously changing speed and direction of rotation Silicon replaces carbon The wear and losses entailed by the use of a commutator are not the only disadvantages of a conventional motor Since it is a purely mechanical construction the manufacturer has rather limited choices regarding current management Things are rather different when we introduce mod ern elec tr
78. appens independently from the energy injec ted into the other two coils manual rotation of the axis and a simple volt meter in AC mode connected between two phases of a unconnected motor enables us in general to generate consequential voltages With the help of this induced voltage we are then ready to detect a synchronous signal from magnet movement Figure 3 shows oscillograms of phases A and C during step 1 We apply the PWM signal to MOSFET T1 while T4 effectively short circuits phase B to ground Phases A and B form a resistor divider theoretically the phases have the same resistor and we receive the PWM signal in A divided by two at point C to which the voltage induced by magnet movement is added All that is left is to choose a precise point on this curve which will give us one piece of synchronisation data all that is needed is one simple voltage reference and one comparator After filtering we can trigger a signal indicating that the induced voltage has reached the value set by the reference also called zero crossing After this commutation can intervene after a cer tain manually adjusted time delay This delay is used to adjust the phase elektor electronics 2 2006 advance and the system efficiency A very strong advance allows us to obtain more motor revolutions at the cost of more current consumption Finally please note that this electromo tive force can only be detected after the coil
79. as DRX 3975D COFDM coded orthog onal frequency division multiplex ing demodulator a Microtune MicroTuner MT2060 digital TV tuner and a Cypress EZ USB FX2LP controller OEMs can put this reference design into pro duction immediately DRX 3975D is the first COFDM demodulator to substantially exceed all requirements of the NorDig Unitied v1 0 2 Receiver Specification This allows a sin gle design for MicStickD to be compatible with all DVB T recep tion standards worldwide Mic StickD enables you to freely roam across the country or throughout your home DRX 3975D uses advanced dig ital filtering techniques in com bination with a powerful A D converter and PLL configuration to ensure a crisp viewing expe rience even under challenging adjacent channel conditions Thus a simple non switchable SAW filter is suffi cient A unique pre SAW IF sense input enables fully autonomous and stable RF AGC control of the MT2060 eliminat ing the need for additional RF AGC circuitry DRX 3975D implements a progressive digital algorithm in the channel estima tor leading to exceptional results in multipath and dynamic echo conditions This is important for Single Frequency Networks and Veronex customisation services The Veronex family of small plas tic instrument cases from Vero Electronics a division of APW is extremely versatile suitable for a wide variety of OEM con sumer electronics electrical and instru
80. at 325 ns in this applica tion Then the current no longer flows to the freewheeling diode but rather to the MOSFET Transistor heating is significantly reduced because then only one resistor equivalent to a few milliohms is visible on the current path A fair number of manufacturers do not take advantage of synchronous rectification because the microcontrol lers utilised are simply not capable of generating such signals Construction The boards are both double sided and components must be soldered to each side a necessary evil to keep the size of the circuit within the correct propor tions Despite the fineness of some copper traces it is very well possible to build these boards with traditional materials The author has made nume rous PCBs with a simple laser printer and a ferric chloride etching solution If you do not have access to boards with through holes then it is best to proceed with installing bridges via lin king each side of the circuit using wire wrapping for example and to cut them as close as possible to the board Next comes installing the integrated circuits such as the micro 5 V regula tors EEPROM quartz crystal as well as the two rows of six MOSFETs for the latter be careful to align them pro perly avoiding raising some of the devices with respect to others because you will have to add a common heat sink If not a fine file can be used to level the MOSFET modules however elektor el
81. ather demanding requirements such as ade quate insula tion and a high leakage induc tance in order to limit the current because the arc is practically a short circuit A circuit consisting of nothing more than a transformer is not particularly interest ing for a magazine dedicated to electron ics It s more educa tional to see how the voltage can be generated in a different manner Here we deliberately decided to use a DC voltage because a DC arc has a nice blue colour instead of the white arc generated by an AC voltage In retrospect that was not such a good decision but we ll say more about that later Despite what we just said we use a transformer to generate the high volt age However the dimensions of the transformer can be kept modest even though it provides a fair amount of power by using a frequency that is considerably higher than the mains fre quency One of the problems in making a DIY transformer for extremely high voltages is the insulation and the breakdown voltage of the materials that are used On top of that we have to ensure that it s reasonably easy to build the circuit as a DIY project For that reason we decided to use an Experimenting with a Jacob s Ladder output voltage of only 1000 V We also decided to use a mains transformer to provide a lower input voltage That at least makes the primary side of the transformer a bit safer We chose a supply voltage of 80
82. ational speed Figure 1 The electric motor is a very effective converter of power aaa v Dissipated power Input power Useful power 050321 11 low load and correspondingly high rotational speed Another characteristic of modern motors is that achieving high rotational speeds greater than 50 000 rpm no longer presents an obstacle In the majority of applica tions electric motors should be able to produce enough torque reducing the need for gearing even to the point where direct drive using a hub mounted motor is feasible Of course a high current is required to achieve a high power output which can be expensive especially when using batteries To achieve the same torque with lower current the number of turns in the motor windings can be suitably increased this has the side effect of increasing the resistance of the windings In either case the power dissipation in the windings must be borne in mind The power dissipation depends on the current and the resist ance P 2R The shape of the windings is also impor tant The available space must be filled as completely as possible high fill factor see Figure 2 and as much of the copper as possible should move within the magnetic flux the ends of the windings contribute to power losses but not to torque It is difficult to achieve high torque and high efficiency simultaneously but there are a few techniques available to try to get the best of both worlds
83. ble Device showcase your products and services e For just 220 VAT 20 per issue for eleven issues Elektor will publish your company name website adress and a 30 word description NEW WAVE CONCEPTS Www new wave concepts com Software for hobbyists e Livewire circuit simulation software only 34 99 e PCB Wizard Circuit design gjss software only 34 99 Available from all Maplin Electronics stores and www maplin co uk OLD COLONY SOUND LAB www audioxpress com Premier source for DIY audio for 35 years New catalog features e Books e CDs e Test amp Measurement e Kits Full range of products and i iti magazines for the DIY audio enthusiast PCB WORLD http www pcbworld org uk World class site Your magazine project or prototype PCB from the artwork of your choice for less Call Lee on 07946 846159 for details Prompt service ULTRALEDS i traleds http www ultraleds co uk tel 0871 7110413 Large range of low cost Ultra bright leds and Led related lighting products Major credit cards taken online with same day depatch For 330 VAT for the year 30 per issue for eleven issues we will publish the above plus run a 3cm deep full colour image e g a product shot a screen shot from your site a company logo your choice Places are limited and spaces will go on a strictly first come first served basis So please fax back your order today I wish to promote my
84. capacitive load on the AC source increases with each section while the apparent capacitance of the high voltage output decreases in the same ratio All the capacitors are actu ally connected in series and with a cascade circuit having ten identical sections the output capacitance is only one tenth of the value of each individ ual capacitor In other words the out put impedance increases significantly One way to counteract this is to drive the cascade with a high frequency volt age and ensure that the transformer supplies a hard AC voltage We used the same philosophy for the cascade stage as for the secondary winding of the transformer Instead of using a single cascade to generate the output voltage we decided to use two cascades Each one supplies half the desired voltage but they have opposite polarities The full voltage is thus pres ent between their two outputs but the voltage with respect to the surround ings is only half as much Of course that doesn t mean the circuit is safe to touch but it does make it a bit safer The approach we took using a DC out put proved to present a problem in practice Despite the high switching frequency the output voltage turns out to not be hard enough so spikes at the output of TR1 can charge the capaci tors in the cascade to a higher voltage than what we expected We also found that the voltage across the diodes can rise to a dangerous level When an arc is struck between
85. clock source is changed and write protection is re enabled From now on all pro grams will run at 20 MHz If you now remove this entire block of code from the listing including prcO 1 and prcO 0 the oscillator will not be changed and the microcontroller will continue operating at 125 kHz To make it possible to observe the result within a finite length of time you must also shorten the wait loops by a factor of 100 void main void pd1 0x0F Set Port 1 0 1 3 be used for output while 1 pL 0 0 Loop C port_toggle High performance imbedded Workshop port_toggle c Ebe k ew Poit fed feb fhe Joe Edo iib Ch coe lel Ge eo 6 Al LTE 64 cet dete eed rte Lite Figure 11 The port_toggle project in the development environment 44 pL pl 2 pl 3 for t 0 t lt 500 t t pl 0 pil pl 2 pl 3 for t I oO o o Il II Or FP FP t lt 500 t The LED will blink somewhat more slowly now but the microcontroller will run with very low power con sumption The internal high speed ring oscillator which runs at 8 MHz provides a com promise between really fast and really slow The Jingle Bells sample project shows how you can use it Copy the following relevant instruction lines into your program prc0 1 Enable High Speed Oscillator 8 MHz hr00 1 asm NOP asm NOP hr0l 1 prc0 0 You should also have a look at the
86. company please book my space e Text insertion only for 220 VAT e Text and photo for 330 VAT a FAA Ul sie eee eee ee a Omen tn ee Te ee Ce O15 G72 Ue 1724 LG 1h leone es momen mre sano ee mane PLEASE COMPLETE COUPON BELOW AND FAX BACK TO 00 44 0 1932 564998 COMPANY NAME 0 eeeesceeeseceseeeseeesseeeseeees VE FS esrissinonissisronioisouissiaivonivoisouieni 2 2006 elektor electronics SHOWCASE YOUR COMPANY HERE Elektor Electronics has a feature to help customers promote their business Showcase a permanent feature of the magazine where you will be able to services directory QUASAR ELECTRONICS www QuasarElectronics com Over 300 electronic kits projects and ready built units for hobby education and industrial applications including PIC ATMEL programming solutions Online ordering facilities Tel 44 0 870 246 1826 Fax 44 0 870 460 1045 Email sales QuasarElectronics com ROBOT ELECTRONICS http www robot electronics co uk e Ultrasonic rangefinders e Motor H Bridge controllers seal e Magnetic Compasses e RC servos and controllers ihe e PIC programmers and components e Electronic Design Development and Manufacturer to industry SK PANG ELECTRONICS http www skpang co uk e ELM OBDII IC e VAG COM Interface e OBDII connector and cable e Modtronix Micro X board e Embedded Ethernet Controller e PIC Microcontroller CAN Bus driver Major credit cards taken online QUASA
87. d our brake switch goes onto bit O of Port B The first icon in the program initializes the CAN board Then we have an endless loop In the loop we get the input from the brake pedal and if it is at logic 1 or the brake is pressed we transmit the CAN message corresponding to the brake being pressed A very similar program in the receiving ECU has an end less loop that constantly monitors the receive buffer and takes appropriate action Ldit Component Properties Genet TH Buller O TX Gutter 1 TH Buttes 2 Fit Buter 0 FK Butter MecsageID fio Ure Hen notabon OFF Dala langit _ Transit buffer detsidi Dal fE D4 p D1 la Dif Dz Do DE PO Dat lz D7 PO Ldit Lomponent Properties General TX Butter O TX Butet TH Buttes 2 PO Butier O rex Butter 1 IF Simpie snitin Use Hew ralk UFF Martsa ID 0 100 F Mastaga lD 1 iM F MHOROR I HHH p re Co he ie i Conclusion CAN is a complex protocol that has many detailed fea tures designed to provide a high data rate high reliabil ity control network between lots of separate processors Implementing CAN is a complex task in languages like C but doing so with Flowcode and E blocks is actually very simple Applications that you might want to consider include a wide variety of home automation tasks control of outdoor train sets burglar alarms and many others The Flowcode CAN component is a free download from the Elektor web site
88. duct series ECKA3DxxxKBP The shape was chosen to match the largest dimension 5600 pF The lead spacing is 7 5 mm for the smaller values and 10 mm for the larger ones Of course the cascade circuits are so simple you might consider building them using point to point wiring but a more robust construction such as this is cer tainly safer That s why we designed a separate circuit board for the cascade stages We also added the option of extending the cascades the circuit boards for the same polarity can be connected in series That means the output voltage can be increased by 10 kV for each board In that case inputs a and b or c and d must be connected to aa and bb or cc and dd The output of each board is bb or dd respectively Bear in mind that the no load voltage per board is a bit more than 10 kV The high voltage transformer The most difficult part of building any sort of converter that uses inductive components or more honestly the most bothersome part is winding the coil or transformer if it s not possible to use ready made components In this case we chose the most difficult option possible by deciding to use a toroidal core If you want to wind a coil on a toroidal core by hand you must first calculate the length of wire neces sary for the required number of wind ings Of course it s a good idea to take a bit more than necessary The toroidal core is not the only obsta cle the winding
89. ducting at the same time which would amount to a short circuit The 2 2006 elektor electronics RC network R6 C7 damps any over shoots that may result from switching the MOSFETs C8 provides additional decoupling for the transformer supply voltage and it must be fitted as close as possible to the associated leads R7 and R8 protect the transformer against hard shorts but they also have another function if the arc conductors are placed closer together than neces sary for the maximum voltage gener ated by the circuit the input of the cas cade stage forms a sort of high voltage Zener The distance between the con ductors determines the maximum charge voltage of the capacitors Any voltage above that level is converted into heat by R7 and R8 Fuse F1 pro tects the high voltage transformer against long term overloads and fuse F2 for the mains transformer protects the entire circuit The supply voltage for the high voltage transformer is provided by a 2 x 30 V transformer Transformers with 60 V secondaries are not standard items and a supplementary benefit is that the cen tre tap can be used to increase the effi ciency of the auxiliary supply circuit for the 4047 due to the lower voltage drop R10 D6 and D4 convert the cen tre tapped secondary voltage into a raw 15 V DC voltage in order to keep the dissipation of the 78L09 regulator rea sonably low The output voltage of the 78L09 is further filtered and buffered by
90. e explanation below to make our setup more attrac elektor electronics 2 2006 UBATT see text UBATT UBATT UBATT tive and better performing than the controllers currently available for sale The final setup could also be accom modated with any other power MOS FET as long as it is capable of commu ting current required A large choice of transistors in SO8 case can work the ones used in our setup are just an example The three phase bridge actually has three identical branches let s focus on one branch only for example the set T22 T23 T17 T29 top left of the dia gram First the micro control signal is raised again With the help of a small MOSFET and a pull up resistor R3 T22 we go from a TTL level to an output toggling between 0 volts and 2 2006 elektor electronics UBATT 2N7002 BSS138 2N7002 BSS138 2N7002 BSS138 BSS138 2N7002 2N7002 Figure 8 Circuit diagram of the power stage module virtually the power supply voltage The 1 kQ resistor is sufficient as a good compromise between the slew rate on the drain and low static power consumption resistor R22 dissipates when MOSFET T22 is ON small cur rent consumption in that case This signal is then handled in two different ways For the P MOSFET we drive a push pull composed of transistors BC817 BC807 We based our choice of these transistors on their low Vpeon characteristic which makes it possible to stay below
91. e goes over 7 V The voltage divider defines the regu lator s output charging voltage and the resistor values are chosen so that 2 2006 elektor electronics Armature field coil 207 electromagnet 100 5 reverse coil reverse switch field current control 050241 12 Figure 1 The original dynamo circuit the output voltage is at the required level when the comparator input volt age at pin 4 is the same as the refer ence at pin 3 R4 and R5 define the level of switching hysteresis and ensure that the MOS FET switches quickly with low losses D3 and D4 protect the comparator from any voltage spikes induced on the bikes wiring system C1 introduces a time constant to the voltage sense level and help to reduce electrical noise produced by the com mutator brushes It controls the repe tition rate of the two stage regulator see text TS4148 and its value can be changed if the dynamo requires a different switching frequency D5 is a fast switching flywheel diode used to suppress the back emf gener ated across the field coil when T1 switches The charging current is adjusted dynamically owing to the high induc tance of the field coil and the flywheel diode action Diode D6 is a Schottky double diode with very low forward conduction voltage and can comfort ably handle the generators short cir cuit output current it replaces the BYV32E 100 D EGP50D 050241 11 Figure 2 Circui
92. e microcontroller For the time being we ll skip the process of developing you own programs so you can enjoy some tangible results as soon as possible After installing the Renesas software package you will find the FDT pro gram in the Windows Start menu The program is shown there in two ver sions a full version and a compact 2 2006 elektor electronics ae E bz ee t a i ee ee ee oS eS eS eS ee F Amat See o8 O Woke a a y E Bed 1 anaa GDA Figure 4 A prototype of the test system built on a lab prototyping board Basic version Start Flash Develop ment Toolkit Basic Figure 5 You must configure several settings the first time you start the program If necessary you can access them later on via the Options New Set tings menu Select R5F21134 as the microcontroller type and select the upper of the two core protocol options Figure 6 In the next window select the serial interface port from the range COM1 COM4 The third window asks you to specify a baud rate for the link to the microcontroller Enter 9600 baud here Figure 7 Finally you have to specify whether you want to enable readout protection for the microcontroller As the risk of criminal industrial espionage is rather small with the initial familiarisation programs you can dispense with any form of protection Save the settings as shown in Figure 8 That completes the preparations Hurr
93. e picture up or down by up to one line With the aid of a cunning control circuit the effective resolution is thus increased 3 Piezoelectric motors the rotor In principle the rotor can be periodically pushed by a linearly moving stator and be held fixed in between pushes the inchworm principle or it can con tinue to move in the same direction because of its inertia More advanced are the so called ultrasound motors Here the piezo element has a voltage applied to one side and is set oscillating using for example a squarewave signal Strong resonance is achieved at a frequency between 30 kHz and 1000 kHz hence the name ultra sound motor The material is shaped so that two oscilla tions a bending oscillation and an extension oscillation are superimposed making the end of the stator move in an elliptical path At one point on this elliptical path the stator touches the rotor advancing it by a few microme tres At a different frequency the two component oscilla tions are superimposed in such a way that the elliptical motion occurs in the reverse direction and the motor turns backwards This principle is used in a motor made by the company Elliptec The compact unit comprises a 2 cm long distinc tively shaped aluminium piece incorporating a pioze ele ment see Figure 1 with a spring at one end The spring presses on the element and its free end pushes on a small wheel or on a small plastic rod A microcontrolle
94. e polar axis shifts by up to 180 If the ceramic is cooled from the molten state the individual crystals are randomly oriented and the material as a whole exhibits no piezoelectric effect Under a strong electric field the polar axes of the individual crystals align giving rise to expanded domains all polarised in the same direction and a pre elektor electronics 2 2006 ferred axis to the material By analogy with the magneti sation of iron in a magnetic field such materials are also called ferroelectric Polarised PZT exhibits an exception ally strong piezoelectric effect in the direction of this axis Since ceramics are now relatively easily available in a wide range of forms they are the materials of choice in several applications which we shall now look at 2 Resonators To construct a drive we will need to use the inverse piezo electric effect Depending on the polarity of the voltage applied along the polar axis the material will shrink or expand by up to 0 15 Using an alternating or pulsed voltage the material can be made to oscillate The partic ular material used the polar axis and the direction of the electric field and the shape of the sample all have an effect on the resulting movement Piezo elements can be made to oscillate in longitudinal length mode thickness extension mode transverse bending mode or shear mode as required 1 Large displacements and corresponding oscillation can be achieved when
95. e regulator will spend its life in a reasonably hostile environment so it is a good idea to protect it as much as possible from the ingress of oil water and general highway crud by potting it inside an insulating casting How ever before we get to this stage it is necessary to do a bit of tweaking on the test bench The two resistors R1 A and R1 B are connected in parallel in the circuit The value of R1 A is speci fied as 6 8 kQ while R1 B needs to be determined empirically with the help of a 470 KQ variable resistor a good quality low ripple finely adjustable power supply with an accurate voltage display or DVM and an LED together with a series resistor to act as an indi cator light During adjustment diode D6 needs to be bridged by connecting a wire link between D and 51 next connect the LED together with its series resistor between D and DF Anode to D Connect two leads to the 470 kQ variable resistor one to the Wiper and the other to one end of the track now solder the other ends of these leads to the pads where R1 B will be positioned The power supply should be connected between 51 and earth of the regulator connections Adjust the output voltage according to the type of battery which will eventually be fitted see Table 1 If the bike isn t used regularly you can afford to increase this voltage level by 100 mV without harming the battery alternatively if it s in regular use the level can be decreas
96. e up to 60 on e Electronic Components e Microcontrollers PIC Atmel e Development Boards Programmers Huge range of products available on line for immediate delivery at very competitive prices IPEVA LIMITED http www ipeva com IPEVA sell low cost USB FPGA development boards IPEVA provide Design Consultancy for Embedded Systems OpenCores IP FPGA ASIC HDL translation and migration Tel 0870 080 2340 elektor electronics 2 2006 products and JLB ELECTRONICS www jlbelectronics com Suppliers of electrical electronic parts and consumables Including e Cable ties bases e Tools hardware e Bootlace ferrules e Connectors e Solvent sprays amp cleaners e PVC Tape e Heat Sink compound KMK TECHNOLOGIES Ltd http www kmk com hk Low Cost DIY Robotic Kits and Computer Controller Boards LONDON ELECTRONICS COLLEGE http www lec org uk Vocational training and education for national qualifications in Electronics Engineering and Information Technology BTEC First National Higher National NVQs GCSEs and Advanced Qualifications Also Technical Management and Languages MQP ELECTRONICS htto www mapelectronics co uk Leaders in Device Programming Solutions e Online shop e Low Cost Adapters for all Programmers e Single Site and Gang Programmers e Support for virtually any Programma
97. econdly diagnostic equipment and training are valuable revenue streams Delving deeper in To understand how the messages in a CAN system are constructed let s consider the temperature dialogue ear 2 2006 elektor electronics A complex system made transparent lier Every message has an ID identification The system designer needs to designate each ID with a function So let s say the ID for can anyone tell me what the block temperature is is ID 400 Correspondingly let s say the ID for the block temperature is is ID 401 The sys tem designer then has to decide how to use the data bytes transmitted to transfer information To keep things simple we can say that the first data byte is O for posi tive temperatures and 1 for negative temperatures We can then say that the next three bytes are used for 100s of C 10s of C and units of C Now in practice this would rarely be the case but as we are interested in teaching automotive technicians among others it might be a good idea to avoid hexadecimal notation and 16 bit numbers at this point So if the temperature is 76 degrees Celsius then the message data would be 0076 For this dialogue the transactions on the bus would therefore be Here we can see the Console ECU requesting the temper ature and the block replying with the data the console then displays the data on the dashboard CAN Flowcode and E blocks do it The simple example above s
98. ectronics 2 2006 be careful not to damage the silicon Note due to very strong currents flo wing peak currents potentially above 25 A it is absolutely imperative to plate tin the MOSFET supply lines as well as the copper lines going toward the three phases or else risk des troying the copper traces A good sol dering iron and a little coordination make it possible to distribute an even layer of tin keeping it flat because these traces pass under the MOS FETs It is also advised to pull two lines of copper between the two MOS FET rows 1 mm diameter cable for example to phases a and b unne cessary for phase c which is right next to its connector Next we can proceed to installing all COMPONENT LIST Microcontroller board Resistors R1 R4 not fited R2 4kQ7 R3 R5 10kQ R 22kQ RZ 15kQ R8 506 RO 5kQ1 R10 R15 6kQ8 R16 3kQ3 Capacitors C1 C2 C3 C5 C6 C7 100nF C4 not fitted C8 10nF C9 C12 4pF7 20V low ESR C10 47pF 6V3 C11 2pF2 5V low ESR Semiconductors D1 BAT54 IC M24CO1 2 2006 elektor electronics of the discrete components such as resistors diodes stage MOSFETs for gate control and push pull stage MOS FETs Finally we advance to soldering the C18 electrolytic capacitor low ESR placed between the two battery supply connectors there is enough space for a second capacitor for those who would like to add another one but
99. ed by around 100 mV With this regulator the output voltage is still not completely inde pendent of load but it is hugely improved compared to the original unit Rotate the variable resistor until the LED comes on then back off until it just goes out The variable resistor is now set to the value necessary for R1 B so carefully remove its leads from the PCB and measure its value Choose a resistor from the E24 or E48 series of resistors closest to the measured value and fit to Figure 5 The author s prototype fitted to the R35 dynamo mounting plate elektor electronics 2 2006 Table 1 Recommended charging voltage position R1 B on the PCB Once you are satisfied that the unit is working correctly the complete PCB can be fitted to a suitable dynamo mounting plate and encapsulated in potting compound the authors fin ished regulator is shown in Figure 5 It is advisable to thoroughly check the dynamo before the unit is fitted and ensure that the earth lead is first dis connected before the unit is wired up Figure 6 The potted unit fitted to the dynamo not forgetting to reconnect once every ted to the bike but apart from this healthily charged and thanks to the thing is in position The electronic unit restriction the regulator should pro improved lighting giving a much will not work with a deeply dis vide many thousands of miles of reli clearer view of the road ahead charged battery or with no battery
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101. el FIFO interface p n FT245R is also available Future Technology Devices International Ltd 373 Scotland Street Glasgow G5 8QB Tel 44 0 141 429 2777 fax 44 0 141 429 2758 sales ftdichip com www ftdichip com 067016 3 Game console development doesn t have to be a War Of The Worlds Nurve Networks LLC s new XGamesStation Pico Edition edu cational game console develop ment kit is now shipping world wide The Pico Edition is a fol low up to the previously released pre assembled XGameStation Micro Edition The Pico Edition is for students and hobbyists that actually want to build the system by hand from a kit of parts The Pico Edition comes as a kit com plete with a solderless bread board and all the components to build an entire working game console in about 1 2 hours Video games generate billions of dollars in revenue each year and game programming books occupy rows of bookstore shelf space Video game development has made its way into college curriculums and entire game pro gramming universities have emerged But video games run on advanced hardware the design of which is a black art that few understand For more than a decade books by Computer Scientist and best selling game development author Andre LaMothe his latest title Tricks of the 3D Game Pro gramming Gurus have taught generations of game developers to create today s cutting edge video games Now his focus is cha
102. elt clips LCD viewing windows can all be supplied Vero Electronics Electron Way Chandlers Ford Hants 053 4ZR Tel 44 0 23 8026 6300 fax 44 0 23 8026 5126 www vero electronics com 06701 6 2 elektor electronics 2 2006 USB UART bridge has built in security dongle Future Technology Devices Inter national Ltd FTDI have unveiled the FT232R the next genera tion of their popular USB UART Bridge family This highly inte grated device includes onboard EEPROM master clock genera tor 3 3 V LDO regulator reset generator and USB termination resistors Only two external decoupling capacitors are required for a minimal configu ration In addition to the full set of modem control signals the device features five IO pins which can be configured in EEP ROM to have several functions including providing a output clock which can be used to drive an external MCU or FPGA Each device has a unique number the FTDIChipID burnt into it at manufacturing time which cannot be altered by the end user Though an encryption scheme this feature can be used by product designers to protect their applica tion software from being copied FT232R features a wide range of royalty free FTDI developed drivers for 32 and 64 bit oper ating systems including Win dows CE Linux and MAC OS The FT232R comes in both stan dard SSOP 28 and miniature QFN 32 5mm x 5mm package options A version of the device with a parall
103. ement that we made on our test circuit that we would like to share with you namely the result E AE 1 a TE from the output voltage measurement with a load of 4 Q see scope picture Clearly visible is some sort of crossover distortion phenomenon that resembles a class AB amplifier This is caused mainly by the unavoidable dead time when switching from one half of the FET bridge leg to the other This time is relatively large at 2k5 about 300 ns We can actually state that this class D output stage behaves as if it was analogue and negative feedback is a necessi ty Apart from a high efficiency and small heatsink there is really no advantage when compared to a good class AB amplifier It is also better not to mention the measures that are required to pre vent the amplifier from interfering with itself or its surroundings such as the output filter that is often placed outside the feedback loop and can only affect the signal in the negative sense Just to be clear all oscilloscope pictures are measurements of a half bridge that is measured with respect to ground 2 2006 elektor electronics 55 ee E BLOCKS E blocks now yo The CAN bus is a resilient high data rate bus for communicating between electronic devices in situations where high data reliability is required One use of the CAN bus is in the automotive industry where it is being used as a substitute for copper wiring looms in cars In this article we refresh our
104. er and coils have a bright green lacquer finish imme diately recognised as techie Without any attempt at exhaus tiveness will describe a couple of experiments that can be per formed by the physics teacher and or his assistant in front of a classroom full of hopefully atten tive pupils Figure 3 shows the most elementary setup described in the manual When the magnet rotates through the coil with the thinner wire on it alternating cur rent is indicated by the meter nee dle swinging to and fro Yes Mike it s AC alternating current which nobody can deny DC then is proven beyond reason able doubt by connecting the meter to the battery and reversing the and connections The coil with the thicker wire can be stacked on top of the other one the 6 V lamp screwed into its socket the mains cord plugged into the socket on the lower coil and nothing happens That is until you insert the iron slab verti cally into the coil openings and hey presto the lamp lights You ve actually built a transformer con sisting of a primary thin wire a secondary thick wire and mag netic coupling stepping down the 230 V mains voltage to a safe level The lamp inten sity can be varied by verti cally moving the iron slab in the coil openings Next up you can replace the lamp by a length of resist ance wire secured between the arms of special Perspex adapter and watch the thin ner wire burn out
105. ered XAP4 to one licensee and is in dis cussion with other prospective cus Advertisement 14 tomers at present The 16 bit XAP4 is the latest addition to Cambridge Consul tants microprocessor core line up There is also the 32 bit XAP3 for more demanding applica tions and in development is the XAP5 that also uses 16 bit data but extends the address bus to 24 bits providing support for larger program sizes up to 16 Mbytes All these processor cores include Cambridge Consultants SIF debug logic which provides full control over the processor and access to its debug registers together with non invasive access to any part of the processor s memory map for data acquisition while a system is running The architecture and design of the XAP3 XAP4 and XAP5 processors was conceived at Cambridge Consultants to fulfil the requirements of modern AS IC based systems running code written by different pro grammers including real time operating systems All the processors include hardware support for privileged operating system modes where code run ning in user mode cannot cor rupt supervisor or interrupt code Code is position independent and there is also support for unaligned data access making programs easy to port and quick to run Most programs will be written in C and the processors feature direct support for many of the language constructs which results in higher code den sity There is hardware support You
106. ery small enclo sure arrived in due course The amplifier appeared to have been well thought Triangle Generator 330kHz 11V_A A R116 820 ZHCS1 ood 11V_A A D104 11V_A A 10k C110 12k 11V_A A LM7121 R106 47k AGND e R107 47k C109 100nF AGND AGND AGND AGND 050183 12 through both externally as well as internally see photo All connections are located on the rear On the front you will find two LEDs and the on off switch The ampli fier is almost completely built with SMD parts and is well presented The enclosure is made entirely from alu minium and as a result has a solid look One detail that attracted our attention however was the way the input signal was routed from the input to the PCB 2 2006 elektor electronics Here two thin twisted litz wires are used per channel but these were seen to run right over the top of the output filters and final power stages Schematic The amplifier was accompanied by a detailed circuit description which R119 TP106 Triangle Triangle gt R120 to Sheet 3 4 10k explained the operation of all parts at length In Figure 1a we show the schematic of one output stage as drawn by the author This clearly illustrates the design of the amplifier together with the triangular wave generator Figure 1b For clarity we have left out all the other parts other channel power
107. es of articles state full name of article and month and year of publication PLEASE USE BLOCK CAPITALS Description Price each Qty Total Order Code METHOD OF PAYMENT see reverse before ticking as appropriate CD ROM CD ROM Elektor 2005 16 25 NEW CD ROM Home Automation NEW 20 Oooo CD ROM ECD Edition 3 NEW 20 M Microcontroller Basics NEW 18 70 A E blocks Starter Kit basic 96 00 E blocks Starter Kit professional 166 00 ae E blocks Easy Internet Kit 232 50 a E blocks Easy CAN Kit 299 00 Bank transfer Cheque UK resident customers ONLY Giro transfer a a amp By PLETE EEE EXPIRY Cale ties a a tarsi se rio VerINIGAON COME crea ae ee SWITCH ONLY Slait Vale ere ree a ESSUEUIMUNTIOENE cecc keen ents eas eee Order For 7 ae Sub total Prices and item descriptions subject to change Please send this order form to The publishers reserve the right to change prices see reverse for conditions without prior notification Prices and item descriptions P amp P shown here supersede those in previous issues E amp O E Total paid Elektor Electronics Publishing Regus Brentford 1000 Great West Road Brentford TW8 9HH United Kingdom Name Tel 44 0 208 261 4509 Fax 44 0 208 261 4447 Internet www elektor electronics co uk sales elektor electronics co uk Address Post code USA and Canada residents may but are not
108. est that generated a maximum modulated PWM signal The generator supplies two clock pulses in anti phase the duty cycle of which can be varied in 16 steps from 0 to 100 This modulation is synchronous with the clock frequency which should result in a clean triangle signal at the output measured via a steep filter With this signal every defect should be immedi ately obvious Disappointing results With the original values 100 nF for the bootstrap capacitors the output sig nal was far from ideal collapsing to 54 Aoo ENNI about half the supply voltage For the clock signal we chose about the same frequency as in the CDAMP namely 313 kHz This frequency is much higher than the rec ommended upper limit of 200 kHz in the datasheet But in the CDAMP we had already halved the clock fre quency at one stage and that made no difference then so we now stuck to the same frequency As a minimum resistance for the dead time we used 2 5 kQ since this theoretically would result in a maximum current of 4 mA The IC is powered from 12 V so that the voltage across the resistor should amount to Vpp 2 V Unfortunately that was not the case in practice At a smaller resistance value the voltage was also reduced The maximum cur rent 5 mA was found to flow when the resistance was 1 2 kQ The voltage was then only about 6 V This is some thing that is not mentioned in the datasheet the value of the dead time can onl
109. f Elektor Electronics Publishing to refund the purchaser any money paid in respect of the goods Law Any question relating to the supply of goods and services by Elektor Electronics Publishing shall be determined in all respects by the laws of England ee i i SUBSCRIPTION RATES FOR ANNUAL SUBSCRIPTION Standard Plus United Kingdom 41 90 48 80 Surface Mail Rest of the World 54 50 61 40 USA amp Canada US 95 50 US 106 50 Airmail Rest of the World 68 90 75 80 USA amp Canada US 120 00 US 131 00 HOW TO PAY Bank transfer into account no 40209520 held by Elektor Electronics Publishing Segment b v with ABN AMRO Bank London IBAN GB35 ABNA 4050 3040 2095 20 BIC ABNAGB2L Currency sterling UKP Please ensure your full name and address gets communicated to us Cheque sent by post made payable to Elektor Electronics Publishing Segment b v We can only accept sterling cheques and bank drafts from UK resident customers or subscribers We regret that no cheques can be accepted from customers or subscribers in any other country Giro transfer into account no 34 152 3801 held by Elektor Electronics Publishing Segment b v Please do not send giro transfer deposit forms directly to us but instead use the National Giro postage paid envelope and send it to your National Giro Centre Credit card VISA Access MasterCard JCBCard and Switch cards can be processed by mail email web fax and telephone
110. f some negative poten tial Making the resistor adjustable could then set the threshold of the sensor George Brennet UK Thanks for that George the explanations look quite plausible but would have to be tested in practice The full circuit diagram as sent in by Alan Bradley appeared in Mailbox December 2005 issue Other readers are invited to add their views on the problem please Retronics on multimeters 1 Dear Jan your article on vintage analogue multimeters in the December 2005 issue One of the explanations of elektor electronics 2 2006 the popularity of the Simpson 260 multimeter on Ebay at least must be that it s still being used in aircraft mainte nance In fact a number of Boeing aircraft maintenance documents mention the use of the Simpson Model 260 Christian Wendt Germany Retronics on multimeters 2 We thank Mr Reznor of Solihull for sending us a copy of the Philips PM241 multime ter service documentation and user manual as well as for confirming that the instru ment was first sold in 1971 The user manual confirmed our assumptions about the use of the strange I 0 4 pushbutton on the range switch of the PM241 and its successor model the PM2411 Improved DECT battery charger Dear Editor I d like to respond to your Summer Circuits item entitled Improved DECT Battery Charger Basically your story is correct and it is desir able to reduce the cha
111. f the assembled board Practical setup Use well insulated wires to connect the cascade boards to the main board If necessary fit them in one or more lengths of electrical wiring conduit The distance between the two inputs of the two cascade boards does not have to be all that large Two to three centimetres is more than enough The distance between the outputs must naturally be larger The voltage differ ence just before the arc strikes can be considerably more than 20 kV As a rule spontaneous breakdown occurs at around 10 kV cm We used a small bench vice with insu lated jaws to hold the two cascade boards for our experiments To avoid a hard short circuit between the cas cade boards when an arc is struck we fitted two 1800 2 10 W resistors from the Vishay AC10 series in series with the electrodes in our provisional setup They proved to be especially good at handling the high voltage To avoid creating secondary breakdown sites we soldered thin wires in series with them and bent the wires so the solder joints were sufficiently distant from the arc location That s because high voltage breakdowns tend to originate on small or pointed surfaces even if the distance between them is rela tively large A transparent plastic housing is the best choice for maximum safety That also makes it easy to mount the elec trodes with adequate insulation During our tests we used a Variac to adjust the voltage of the circ
112. fice within 10 days UK 14 days Europe or 21 days all other countries Cancelled orders All cancelled orders will be subject to a 10 handling charge with a minimum charge of 5 00 Patents Patent protection may exist in respect of circuits devices components and so on described in our books and magazines Elektor Electronics Publishing does not accept responsibility or liability for failing to identify such patent or other protection Copyright All drawings photographs articles printed circuit boards programmed integrated circuits diskettes and software carriers published in our books and magazines other than in third party advertisements are copyright and may not be reproduced or transmitted in any form or by any means including photocopying and recording in whole or in part without the prior permission of Elektor Electronics Publishing in writing Such written permission must also be obtained before any part of these publications is stored in a retrieval system of any nature Notwithstanding the above printed circuit boards may be produced for private and personal use without prior permission Limitation of liability Elektor Electronics Publishing shall not be liable in contract tort or otherwise for any loss or damage suffered by the purchaser whatsoever or howsoever arising out of or in connexion with the supply of goods or services by Elektor Electronics Publishing other than to supply goods as described or at the option o
113. fit able operation keeping the battery 050241 1 Advertisement XGAMESTATION _ i OO mm amn M Hirer res HON it aD Dimma Tout Der WD Dag Coecn m A i SERVICING YOUR COMPLETE PROTOTYPE NEEDS Design memre fy ere Aten BO JEDD Sirris E kpa Appr n Laer fA IGLU DES 1 Prototypes af a fraction of ie cosi ineuciry Standard qualyy ome oe pean Air ha Tooling and setup included Follow D series ruts i ee _ Fay dette OT A Any contour CAM CAD consuitingy eee ee E a m pm z ee E z ii l Art LETT diu Gas es erat a a m Ps ihe 4 j i Ve a g er ES ee ooo pepo m l E Tooling Ph 925 736 2090 j dhr DAL CA taiea holopiois PCBs in x 3 24 hours miro 0 00 ceo lap LPL com VAT 29 89 F ering min may ky Frico 40 oe Pad ie ae y be por gree a vipi an let a BSI aad FOTO Kann age m En ri Bel ie ee ar 3 rm oe Tel 01635 40347 mewbury Electronics ud Far 116 Saa Femin Rood hry Beri 510 TAD email chOouSnewbery Loom cou mwaa uk WWW PCB POOL COM ale Frote WT Grophitede GERD iF Slectronics EJ 2 2006 elektor electronics 73 HANDS ON DESIGN TIPS 74 Automatic Gain Control for DRM Receiver Burkhard Kainkar A DRM receiver typically supplies an intermediate frequency IF out put signal of 12 kHz to the PC soundcard Demodulation is han dled by
114. foi it A UPCI Serial Cards oe Discover our great value for money range of multi port UPCI serial cards Supporting from two to eight ports the range includes RS232 RS422 RS485 and opto isolated versions Our 4 port and 8 port models can connect through external cables or the innovative wall mounting COMBOX priced from 21 00 UPCI 200L UPCI 400HS EasySync Ltd 373 Scotland Street Glasgow G5 8QB U K Tel 44 141 418 0181 Fax 44 141 418 0110 Web http www easysync co uk E Mail sales easysync co uk 4 Port UPCI RS232 Serial Card with Spider Cable or COMBOX IO extra Prices shown exclude carriage and VAT where applicable WTO AGU MAILBOX 2005 Cumulative Index The Cumulative Index for Elektor Electronics year Volume 31 2005 was not printed in the December 2005 issue to save pages for articles The document has been duly produced however and may be downloaded free of charge from the December 2005 page of our website at www elektor electronics co uk Select Magazine then 2005 then December Readers wish ing to obtain a free copy on paper may contact our sales office at Elektor Electronics Publishing 1000 Great West Road Brentford TW8 OHH UK Tel 44 0 208 2614509 Editor Website news and announcements A new Upgraded server has been installed at www elektor electronics co uk to handle the increasing amount of traffic generated by our website We thank our customers for their
115. gnal that drives the HIP4082 is not quite sinusoidal because of the negative feedback that is present 2 2006 elektor electronics Chinch Input D fot g OA 200 es TO aA gree i 1 SEA DH 1 CO Oe Hr HI fiery Fii GH measurements we got the feeling that something was not right with this amplifier Perhaps a component was defective However we could quickly rule that one out since the other chan nel provided similar measurement results What was going on here Back to the designer Consulting with the designer of the cir cuit caused a reaction of disbelief over our measurements He also asked us to assess the amplifier acoustically The latter turned out no surprise here to be rather bad During the listening test we also kept an eye on the speaker signal with an oscilloscope and even then the crossover distortion in the bridge halves was visible We were also asked to confirm that the duty cycle of the amplifier equalled 50 without an input signal This was correct and can be determined from the oscilloscope picture that clearly shows that the output is at half supply voltage Next item on the checklist was the power supply capable enough That could surely not be the problem we had used a big lab power supply that is capable of delivering at least 40 A After reporting our results we were asked to make a few more measure ments on the amplifier such as power supply voltage differential input
116. gree rotation For two pole pairs we must perform two times six commuta tions or 12 commutations Here we see the ratio enabling the conversion between electrical and mechanical fre quency a motor which has for exam ple seven pole pairs revolving at an RPM of 15 000 or 250 Hz will actually operate at an electrical frequency of 7 15000 60 1750 Hz or a commuta tion frequency of passing from step n to n 1 from 6 1750 10 5 kHz Be careful not to confuse commutation fre quency and applied PWM frequency on the motor windings as they are two very independent things The first controllers that came into being some years ago actually came with Hall effect sensors informing the electronics about the rotor position and causing commutation at the right time More recently in response to a wider motor market sensorless solutions were introduced being capable of accommodating connections to three phases Clearly our setup falls into this last category Detection of the rotor position and synchronisation At each step only two or three phases are utilized Why not use this floating phase to send the signal which will trigger the next commutation This is an excellent idea relating to the elec trical data moved at this specific point And what happens When the motor runs the movement of the magnets induce a voltage increasing or decrea sing to the unenergised coil terminals electromotive force and this h
117. gs the rotor with it Exchanging two of the phase connections will reverse the direction of the motor The similarity to three phase motors is striking In principle the electronically commutated DC motor is identical to a syn chronous motor although the field rotation rate is not fixed in relation to the mains frequency and the motor need not lose step with the field under high load The types of brushless motor described here generally produce their own field fre quency in the control electronics the field turning as the rotor does and the windings only being switched when the rotor is in the correct position To determine the position of the rotor poles magnetic field sensors such as Hall effect sensors can be used more recent designs however dispense with the sensors and determine the position of the rotor from the back EMF pro duced by the motor which is available across any winding that is not at that moment connected to the power supply Since this voltage can only be measured when the motor is running start up must be done in open loop mode without this feedback sensorless motors therefore tend not to start up very smoothly As you would expect from Elektor Electronics we put theory into practice elsewhere in this issue you will find a project to build a controller for brushless DC motors Delta arrangement A Star arrangement Y start of winding end of winding 050321 20 Figure 16 The motor winding
118. has been completely demagne tised which means waiting after each commutation Figure 4 clearly shows this phenomena when passing from step 1 to step 2 Brushless controller for R C The proposed setup depends on a recently introduced microcontroller put on the market by the STMicroelectro nics company the ST7MC MC for Motor Control This unit contains eve rything you need to drive a 3 phase stage permanent magnet motors as well as induction motors in addition to a list of comparators digital filters and other reference voltages in order to operate all types of brushless motors as in this example Here we need to make an 8 bit core with 8 kB of Flash memory and 384 bytes of RAM just enough to handle the software required for this application More UBATT L4941 BAO5FP UBATT 2 2006 elektor electronics standard peripherals are used to bols ter the core like a 10 bit CAN two 16 bit timers one supply voltage supervi sor one PLL to double and filter the clock signal and so on Schematics a modular approach Considering the nature of this applica tion we had to find a compromise bet ween compactness component sup ply and performance in comparison with what we can already find on the market For compactness a modular approach was selected in order to be able to electronically separate control electronics and the power stage Some readers could for example adapt the control module to a home
119. he PCB The design is typical of many embedded products We can see RAM and ROM chips the baluns for the Eth ernet connections and an ADM5120P at the heart of the router This chip contains everything required to imple ment a router a MIPS based processor an embedded switching system for the four local Ethernet connections two MACs for the Ethernet communica tions two USB ports a serial port and a handful of general purpose I O lines Not all of these can be accessed from the outside of the router The two most obvious missing connectors are the two USB ports This can however be rectified If you take a look at the PCB inside the router you ll see that some space has been reserved for the USB ports It s just that the parts for these weren t mounted during the manufacturing process It s therefore possible to add these USB ports your self see inset USB ports are obviously a nice addi tion but what can you do with them 2 2006 elektor electronics 47 MODDING amp TWEAKING As it is the router can be easily hacked by modifying or replacing the pro grams stored in its Flash memory A number of people have done this already and have added several func tions to the firmware Details can be found in references 1 and 2 One problem you come up against when adding software to the Flash memory is that the available memory is fairly sparse The Flash ROM inside the router is just 2 Megabytes
120. he supplied Acrobat Reader program articles are presented in New the same layout as originally found in the magazine The DiskMirror utility on this CD ROM allows your earlier Elektor year volume CD ROMs 1997 2004 to be added to a large archive on hard disk for fast access and easy reference A built in search function allows you to find references in any article from the archive on hard disk or from individual year volume CD ROMs you have available 16 25 US 28 75 ISBN 90 5381 202 4 e All articles in Elektor Electronics lah Volume 2005 on CD ROM Order now using the Order Form in the Readers Services section in this issue Elektor Electronics Publishing Regus Brentford 1000 Great West Road Brentford TW8 9HH United Kingdom Tel 44 0 208 261 4509 See also www elektor electronics co uk INDEX OF ADVERTISERS Allgood Technology Showcase www allgoodtechnology cOM 80 ATC Semitec Ltd Showcase www atcsemitec co Uk Sia i245 684 oho daa 80 Audioxpress Showcase WWW AUCIOXPFeSS COM cee eee 81 Avit Research Showcase www avitresearch cO UK 2 0000 ees 80 Beta Layout Showcase WWW PCD POOI COM 6 0 eee 73 80 Breadboarding Systems www breadboarding c0 UK 00 eee eee 11 Burn Technology LTD Showcase WWW DUINTEC COM 00 ees 80 Compucut Showcase WWW CO
121. he system is as shown interconnected ECUs in ee A key feature of CAN is reliability and this is kept to a a car maximum by keeping traffic on the CAN bus to a mini 56 elektor electronics 2 2006 u CAN mum In a conventional network you might think that the foot pedal would tell the central processor on the instru ment panel that it has been pushed down and the instru ment panel would then tell the light cluster ECUs to turn the brake lights on and so on Surprise CAN works differently When the pedal is depressed the brake pedal ECU issues a message effectively stating brake pedal pressed This message is issued to the whole bus The light cluster ECUs are programmed so that when they see the brake pedal pressed message on the CAN bus they power up the appropriate lamp This has kept message flow to a minimum and if the instrument panel ECU or any other ECU is not working then the core important functions of the network are still active This is an example of one type of data exchange for impor tant mission critical data if your brake lights don t come on then you could run into trouble or it would run into you However if this method was employed by all devices con nected to the bus then the traffic would be quite large with more traffic meaning reduced reliability So a sec ond technique for data exchange is used Looking at tem perature monitoring for example the central inst
122. hem Martin UK Our statistics show that 0 01376 of our readers actually attempted to run the DVD in a CD ROM drive Seriously only five of about 100 000 DVDs pro duced for Elektor s international print run could be confirmed as defective These were replaced free of charge by our Customer Services department Nice try also those of you who claimed to have bought a November 2005 issue without the DVD secured to page 13 but also without proof of purchase of the magazine Not forgetting those asking where they could download the entire DVD contents We guess this is natural if you give away some thing for free Battery backup for bike help please 2 Hi Jan this is in response to Alan Bradley s call for help with his circuit Mailbox December 2005 Ed The 100 pF in series with the diode and the 10 pF con densers need a path to get rid of the negative potential built up at the junction nega tive electrode to anode of diode A 10 k resistor to com mon would be a suitable value would also render the 100 uF unpolarized by adding a back to back other 100 uF as now there will be AC on the condenser plates like the two left ones at the alternator connection a dynamo sup plies DC think It could have worked if the condenser started leaking Alternatively it could also be solved by keeping the 100 uF as it is and placing a resistor in parallel on it once again to create a path to get rid o
123. her Correspondence may be translated or edited for length Clarity and style When replying to Mailbox correspondence please quote Issue number Please send your MailBox correspondence to editor elektor electronics co uk or Elektor Electronics The Editor 1000 Great West Road Brentford TW8 9HH England elektor electronics 2 2006 Easy 3 PiCmicro Starter Pack 99 00 dsPIC EasydsPIC2 dsPIC Starter Pack MICROCONTROLLER DEVELOPMENT TOOLS High quality development board Built in USB 2 0 programmer Windows 98 ME 000 P compatible Suppewis 4 14 18 28 and 40 pin DIP microcomiroiers trom the 10F 12F 16F and 14F PiCmicro families On board LEDs switches 7 segmerntt displays potentiometers AS 232 internace USS and FSF conmecdorr All VO lines available for expansion EasyPiC3 Starter Pack includes PIC1F 452 microcontroller 16 character LCD lt 128x64 pixel graphic LOD DS 18520 temperalure sensor USB programming power lead Programming sofware and examples High quality developmen board Built in USB 2 0 prograrnrmer Windows 98 ME 2000 XP compatible Suppwis 18 28 and 40 pin DIP digital signal conirollers fram dsP Cad familly Omboard LEDs switches poterli ometes AS 232 interlace PS2 and ICE connectors and MMC SD card Sky All VO lines available tor expansion EasydsPIC2 Starler Pack inc
124. hows that at a very high level the way CAN works is very simple One of the real strengths of the Flowcode software supplied with E blocks is that it allows all of the complex parts of CAN to be taken care of in the background and only exposes users to the messaging parts of CAN Within Flowcode some custom macros have been written for the E blocks CAN controller board that allows it to be easily controlled by those with little programming skill The macros provided allow the ID and data to be easily set up in the transmit screen Figure 4 which is invoked in a single Flowcode icon Similarly in the receive dialogue screen Figure 5 the ID and data can be picked up by a single Flowcode icon and placed in user variables In the receive dialogue screen more advanced users can click on the details button to access further advanced functions like filters and masks as well as view the CAN data string but for most users these details aren t terribly important Putting this together The screendump in Figure 6 shows a Flowcode pro gram for a notional brake pedal in a car Here we are using the E blocks Multiprogrammer with a 40 pin 57 ieee E BLOCKS Figure 4 Transmit dialogue screen Figure 5 Receiver dialogue screen Figure 6 A simple Flowcode program that sends CAN messages when the brake pedal is 58 activated PIC16F877A with internal USART Onto this we place the CAN board on port C an
125. ies at the root of elec tricity which in turn is at the root of nearly all electronics The sub ject of this month s instalment of Retronics is a small brownish suit case which when first opened Figure 1 took me back instantly to physics classes about 30 years ago in particular those aimed at teaching me the princi ples of electricity and magnetism The suitcase was shown to me by a retired classroom assistant who had kept it in safe storage for more years that he could remember In fact he had two of these suitcases one incomplete the other complete unused and in pristine condition as shown here The Electricity and Mag netism Demonstration Set for Physics Classes Fig ure 2 contains two large coils one with a lamp fit ting on it a centre zero moving coil meter its nee dle so large it can easily be read it from the back of the classroom a magnetic rod with North and South poles a sheet of hard plastic a slab of soft iron a 6 V lamp a 4 5 V bat tery an assortment of resistance wire test tubes containing iron powder and I think copper fil ings an adapter holder for the resistance wire a mains cord and last but not least a copiously illus trated teacher s manual The suit cases and the components inside are hand made to very high stan dards with metal clamps and pieces of wood carefully secured at critical places inside to prevent damage to the highly prized con tents The met
126. in meaning to press The reverse phenomenon was also observed certain materials change shape in characteris tic ways when a voltage is applied Apart from piezo electric gas lighters and quartz crystals which exploit both processes technical applications were of rather a recondite nature In the last ten or twenty years there has been a resurgence of interest in the piezoelectric effect with the promise of making electric drives with revolution ary characteristics That this has become possible is due in no small measure to advances in materials science and micro controller technology Ceramics in fashion The piezoelectric effect is observed in many naturally occurring materials One example is quartz if pressure is applied along a particular axis of the crystal the so called polar axis a voltage can be measured across the corresponding opposite sides for more details see the text box If a voltage is applied across the crystal it shrinks or expands This is known as the inverse piezo electric effect There are synthetic materials that exhibit even better characteristics than quartz Lead zirconate titanate PZT a ceramic can even be polarised which means that the axis and polarity of the piezoelectric effect can be determined at will 1 The ceramic is com posed of a large number of individual crystals fused together which gives rise to an interesting effect Under a strong electric field the orientation of th
127. into a load of 4 Q It is common practice to measure the distortion at 1 kHz with an output power of 1 W To our surprise this turned out to be sev eral percent measured from one half of the bridge to ground Also when view ing the signal on a scope the distor tion was clearly visible The sine shape was flattened on top quite early on Measuring symmetrically between the two half bridges the signal was rea sonable however But even then the distortion was still more than a worry ing 0 5 Is there something wrong with the prototype perhaps it is not 1 SOO OS TOA PO EE CATEL adjusted properly Since the amplifier only operates from a single supply volt age both the FET outputs have to be at half the power supply voltage for opti mal output This appeared to be correct and this was also the only adjustable parameter in the entire design The fact that the symmetrically meas ured distortion is lower can be explained by the fact of the symmetri cally implemented negative feedback Any errors in the signal processing are then reduced depending on the amount of negative feedback But since the schematic clearly shows that both halves of the bridge are identical and are driven by identical antiphase sig nals the difference between the out puts apart from the phase and there fore the distortion should be minimal Each of the bridge halves actually pro duced a signal with different amplitude and distortion
128. ion of attempting multiple experiments and why not in the end write your own custom software It is entirely possi ble for example to implement a regu lation loop like the one described in the application note mentioned above very useful for R C helicopters in order to have constant rotor timing Plenty of room for experiments If you use our setup as your target board during every debugging or programming session you will have to add pull up resistors to the ground or V on the K2 connector as already explained in the construction paragraph in order to ensure that all the MOSFETs are OFF open switch actually outputs MCO0O to MCO5 of the micro in this specific example move into high impe dance and no longer ensure that they are OFE 050157 1 Internet links Softecmicrosystems www soffecmicro com COSMIC www cosmicsoftware com download_st7_16k php STMicroelectronics www st com Application note www st com stonline books pdf docs 10267 pdf Starter kit ST7MC www softecmicro com products html type detail amp title AK STZFMC 31 Quasar Electronics Limited PO Box 6935 Bishops Stortford CM23 AWP United Kingdom Apya a angg tie nik UK Standard mmmm 3 7 Day Delivery 3 95 UK Mainland Next Day Delivery 8 95 Europe EU 5 95 Rest of World 9 95 up to 0 5Kg Tel 0870 246 1826 to Quasar Electronics Prices include 17 5 VAT We accept all major
129. ip ID technology helps protect your application software I O Drive Capability from 5 5v down to 1 8v levels at 4mA or 12mA programmable strength I O Modes synchronous and asynchronous Bit Bang I O OS Support in house developed amp supported drivers for Windows 98 ME 2K Server 2003 XP XP64 Embedded XP Mac OS8 9 X Linux Win CE many 3rd party drivers Driver Options VCP and D2XX drivers for all Windows platforms and Linux Technical Support a wide range of evaluation kits available from the outset make evaluating the FT232R a snap Package Choices SSOP28 and QFN32 Interface Options also available with a parallel FIFO interface p n FT245R v LESS External Components no crystal EEPROM or USB termination resistors required Board Space new QFN package takes up only 25mm of pcb area Manufacturing Cost minimal external component count coupled with competitive pricing reduces the overall cost 22R Programming FT232R comes pre programmed with F112 each part having a unique USB serial number burnt in This eliminates the need to program the EEPROM in many cases and saves on production time cost Time to Market FT232R eliminates USB driver and firmware development in most cases ae e EVAL232R ud Rate y Generato thus significantly reducing time to market E FTDI E Chip Europe HQ Future Technology Devices Inter
130. itance is a factor of 3 5 greater so switching losses will be increased The buffer stage for driv ing the MOSFETs is not actually designed to handle that The drive circuitry Figure 1 is built around a nearly antique IC from the 4000 family the 4047 which is described as a monostable astable multivibrator It has a separate output OSC for the internal astable multivi brator and it also has a divide by 2 cir cuit with two antiphase outputs P1 allows the frequency at the divider out puts to be adjusted over a range of approximately 35 110 kHz That makes it possible to select a different core material or change the number of turns if so desired In our tests we were able to leave the frequency at the lowest setting P1 turned fully anti clockwise The IC is operated in the astable mode The two antiphase out puts are quite convenient for driving the MOSFETs Unfortunately a 4000 series output cannot provide very much current so separate buffer stages are necessary to drive the high gate capacitances of the MOSFETs The buffer stages consist of a pair of complementary emitter followers formed by T1 T4 Type BC337 and BC327 transistors are used for the NPN PNP pairs They have a peak switching rating of 1 A and sufficient gain The switch off time of the MOS FETs is reduced by a factor of around 3 by connecting an extra resistor and diode across R3 and Rb That ensures that the two MOSFETs will never be con
131. le mixture Compared to conventional injection nozzles which use magnetic valves the piezoelectric actuators are some three times faster and allow multiple injections per stroke of the cylinder This lets the fuel burning process be further optimised A closer look at a quartz crystal The piezoelectric effect can readily be explained with reference to The piezoelectric effect is almost exclusively linear which means that quartz SiOz The atoms in quartz form a regular grid with each silicon atom being surrounded by a tetrahedral arrangement of oxygen atoms Figure A The oxygen atoms tend to attract electrons from the silicon atoms making the silicon atoms positively charged and the oxygen atoms negatively charged If pressure is applied to the quartz crystal along the axis joining an apex of the tetrahedron to the middle of the opposite base the opposing charges are pushed relatively closer together giving rise to an electric field Figure B and a potential dif ference can be measured This distin guished axis of the quartz crystal is called a polar axis If pressure is applied perpendicular to this axis the quartz crystal expands along its polar axis because of its elasticity The charges move in the opposite direc tion resulting in an oppositely polarised electric field Figure C The piezoelectric effect is not present in all crystal structures if the positive and negative charges are arranged in a cubic lattice a
132. le steps allow an exceptionally high positioning precision Once the desired position is reached a DC voltage can be applied which allows partial forward or reverse steps with accuracy in the nanometre range This makes the piezoelectric motor ideal for sliding stages in nanotech nology applications and microscopes and for microma nipulators in analysis and medicine Figure 3 5 Machine tools where only a small holding force is required can also make use of piezo motors In contrast to the motor described above which only requires a sin gle channel to control it this type requires two four or even more signal output channels Trinamic in Hamburg have developed a control module for use with the piezo In a piezoelectric motor the oscillation of the fixed piezo element the stator must be transferred to the moving part 36 elektor electronics 2 2006 motors produced by the Swedish manufacturer Piezomo tor 6 It generates four phase shifted periodic signals with a programmable waveshape at a resolution of eight bits Figure 4 Travelling waves The principle of the travelling wave motor developed in the early 1980s in Japan can be used to obtain precise rotational motion The annular stator is made up of indi vidual piezoelectric elements with alternate polarisations connected together with a continuous metal contact If a DC voltage in the region of 200 V is applied the ele ments alternately expand and contract deformi
133. le lor expansion BIGAVA Starner Pack includes ATmegai28 MCU module 162 character LCD v 1238064 pixel graphic LOD DS1BS20 temperalure sensor USS pregramming power lead Programming sottware and examples High quakly development board Budl in USB 2 0 programmer Windows SAME 20HWXP compatible Supports 5 20 28 and 48 pin DIP PoC mited signal controllers On board LEDs swilches prenti ometers AS 232 imertace RS 485 interlace CAN meraca real time clock and MMC SD and CF card slots Al PO lines available for expansion EasyPSoCd Starter Pack includes 46 pin PSoC microconrofer 16x character LCD 128x684 pikal graphic LCD 0518520 lomperalure sensor USB programming power lead Programming software and examples Breadboarding Systems can supply all MikroE lektronika products trom stock Credit and debi cards accemled Prices shown exclude delivery and VAT Breadboarding Systems Software and hardware development tools Tel 0845 226 9451 Web www breadboarding co uk LTO NEWS amp NEW PRODUCTS 12 Pocket sized DVB T receiver design with USB 2 0 Micronas today announced immediate availability of Mic StickD a production ready refer ence design which enables watching and controlling live DVB T broadcasts on any USB 2 0 equipped desktop and note book PC The design is built around best in class components to achieve the required reception performance a Micron
134. lers electronics and computers In this section we will be able to examine and build some of his projects This project can also be found on the Internet at http sprite student utwente nl jeroen projects lbO0002 1 48 elektor electronics 2 2006 Step into the fascinating world of microcontrollers Microcontroller Basics NEW MICROCONTROLLER BASICS Microcontrollers have become an indispensable part of modern electronics They make things possible that vastly exceed what could be done previously Innumerable applications show that almost nothing is impossible There s thus every reason to learn more about them but that raises the question of where to find a good introduction to this fascinating technology The answer is easy this Microcontroller Basics book combined with the 8988252 Flash Board project published by Elektor Electronics This book clearly explains the technology using various microcontroller circuits and programs written in several different programming languages In the course of the book the reader gradually develops increased competence in converting his or her ideas into microcontroller circuitry ISBN 0 905705 67 X 230 Pages 18 70 US 33 70 Flash Microcontroller Starter Kit Step into the fascinating world of microcontrollers with the Elektor Electronics Flash Microcontroller Starter Kit Order now the ready assembled PCB incl software cable adapter amp related articles
135. lkit 39 MICROCONTROLLERS The hardware The low profile PCB with pre assem bled SMD components is supplied with two pin headers that you must fit and solder yourself Figure 1 That yields a complete processor module in the format of a 32 pin DIL IC Figure 2 There is also space reserved on the board for a 14 way pin header but it does not have to fitted right away because it is only needed for the E8 debugger The actual microcontroller the R8C 13 is contained in the 32 pin LOPF SMD package which measures 7 by 7 mm and has a lead spacing of 0 8 mm The marking R5F21134FP U0 reveals that it is an R8C 13 with 16 KB of flash ROM We selected the R8C 13 because it has the same characteristics as its siblings R8C 10 R8C 11 and R8C 12 The board also comes fitted with a 20 MHz crystal and the neces sary Capacitors as well as several other capacitors and resistors Alto gether this amounts to a complete microcontroller system Once a pro gram has been loaded all you have to do is connect a 3 3 V or 5 V supply volt age and you ve got a working system Program code can be loaded using a serial interface no special program ming hardware is necessary That s because the microcontroller has a debug interface and a corresponding boot program that can be used to copy the software into the flash ROM Figure 1 The hardware you can order from us at low cost forms a complete microcontroller system
136. ludes dsPIC30F4013 digital signal controler 16x charader LOD 128064 pixel graphic LOD USE programming power lead Programming software and examples BIG 3 80 pin PiCmicro Starter Pack 119 00 dsPICPRO 64 80 pin dsPIC Starter Pack 149 00 AVR EasyAV 3 AVA Starter Pack 99 00 Built in USB 2 0 programmer e Windows 8 ME 2000 4P compatible Supports 8 20 28 and 40 pin DIF AVRA microcontrollers On board LEDs switches potenti ometer AS 232 interlace 12 bit A D and DA and MIMC SD card slot All 0 lines available for expansion EasyAVA3 Starter Pack includes ATMaga8535 microcontroller Tix charactar LCD 128064 pixel graphic LOD J DS18520 lemperalure sensor a USB programming power lead Easy 8051 Starter Pack 99 00 Programming coltware and examples High qually development board Buil in USB 2 0 programmer Windows S8 ME O00 XP compatible Supports 20 and 40 pin DIP Atmel 8051 Flash microcontrollers On board LEDs swiiches polenii ometer RS 232 interlace 12 bit A D and D A and two Additional 6 bil 140 ports All VO lines available for pansion Easy8051 Starter Pack includes r 40 pin 8051 microcontroller IE character LED lt 128064 pikal graphic LCD 0518520 lemperaiure sensor USB programming power lead Programming sitwa and examples BIG 5 64 pin AVR Starter Pack 119 00 Eas
137. made power stage Moreover two double sided modules give us four layers of copper for soldering the components which is far from being a luxury We opted for a discrete approach and avoided exo tic integrated circuits that are practi cally impossible to find in general retail stores On the performance side the microcontroller is really what makes the difference Its digital filters easy to configure give us the freedom to do C3 2u2 5V 100n MCCREF VAREF 27 SCL 7 Ps PA3 AINO SDA 7 WC M24C01 i PA5 AIN1 PB1 MCIA PB2 MCIB PB3 MCIC MCO3 MCO4 ST7MC1 cos PD2 ICAP2 AIN12 PDO AIN11 PD3 ICAP1 AIN13 PC3 OAN VPP PD5 PC2 OAP PD4 AIN6 OAZ RESET m OSC1 OSC2 see text Figure 5 The control module how could it be any simpler without RC filters in order to extract information faster without added phase delay Even more interesting this micro permits four sampling methods one of which is patented and two of them are implemented here guaranteeing us a progressive secure start up The micro board The schematics for this board shown in Figure 5 are brilliant by their sim plicity The power supply for the micro the receiver and the servos are built with the help of two 5 V 1 A regulators in parallel with a low drop type Select the BAOSFP model rather than the L4941 which offers standby voltage of more than 20 V approximately 18 V for the L4941 Obviously there is no ques tion of po
138. matically downloads the latest changes The first update will then be installed auto matically The PC must then be restarted before you continue 3 Update HEW This step is only necessary if you have not already down loaded the latest update from the Internet and installed it Run the first HEW update from the CD by starting hewv40003u exe in the Software HEW_V 4 00 03 001_Update directory on the CD That will update your compiler to the latest version Database Version 7 0 That is important because the sam ple projects have been generated for this version Although you can use the new version to load older projects which will then be updated automatically regressing to an older version of the compiler is not that easy 4 Debugger package Run the installer file m1 6cdebuggerv100r01 exe in the Software Debugger Package directory on the CD Follow the instructions of the installer program and confirm your agreement to the licence conditions Everything else is auto matic You must restart the computer after this installation 5 Flash Development Toolkit Install the FDT by running the installer file fdtv304r00 exe in the Software Flasher_FDT directory on the CD Confirm all default settings Everything else is automatic When everything has been installed you will find the Renesas program group under Start All Programs The two relevant programs in the group are High performance Embedded Workshop and Flash Development Too
139. mentation applications Available as standard in three colours four plan sizes nine heights plastic and aluminium front panels and three different configurations The extensive range of accessories and a short lead time full customisation serv ice makes it one of the most adaptable small enclosures on the market As the original manufacturer VERO Electronics is fully equipped with the required sys tems and equipment to be able R TRARSPAREAT ERD PAWEL BELT CLIPS FR i r j Li wR DU i to offer a rapid response proto typing service short run pre pro duction quantities and volume manufacturing of modified and customised versions The Quick Customisation Service is simplic indoor reception The Microtune MT2060 single chip tuner is engineered to com bine low power consumption with excellent radio frequency RF performance Its single 16 MHz crystal is sufficient to pro vide the clock signal for both the MT2060 and DRX 3975D The Cypress EZ USB FX2LP controller easily handles the high data rate of digital television All of these features combine to deliver top quality TV images from a USB device measuring only 2 2 cm by 6 2 cm 0 9 by 2 5 The MicStickD tuner and capture BATTERT LORFARTAENTS HrU a Ar a a 3 IE RAME RET RAMS F i ATH Ph FAC COAMPATIEVLITY ity itself AutoCAD files or engi neering drawings are freely available to customers who sim ply mark them up with the
140. method is also diffi cult The reason we chose a toroidal core is the high secondary voltage To make it possible to use standard mate rial and avoid using expensive high voltage wire we decided to wind the secondary in a single layer That s the only way to ensure that the voltage between adjacent turns is as low as possible If we assume that spikes up Figure 7 A fully assembled cascade board Small but highly dangerous 2 2006 elektor electronics 67 JACOB S LADDER to nearly 2 kV occur the voltage between two turns of the secondary winding is only 13 V In order to have a well defined voltage between the pri mary and secondary windings we wound the secondary with a centre tap that is connected to circuit ground The secondary winding is wound first in two stages which is why two con nection points for the centre tap are provided in the ground plane Each turn requires approximately 105 mm of wire In total you thus need two 8 m lengths of 0 5 mm enamelled copper wire It s not critical to have exactly 75 turns in each half of the winding a few turns more or less won t matter What s important is to wind the turns patiently and place them tightly together on the core Be careful to avoid putting a kink in the wire Make sure that the two ends of the second ary winding emerge at a certain dis tance apart so they fit well to the cir cuit board The same applies to the two ends for the centre tap
141. mmer for all Flash devices No external power supply making it truly portable Supplied with box and Windows Software ZIF Socket and USB Plug A B lead mot incl Kit Order Code 3128KT 34 96 Assembled Order Code AS31286 44 56 PIC ALL PIC Programmer eee PICALL will program virtu ally all 6 to 40 pin sanal mode AND parallel node PICI6CSs family pro wo grammed PIC micro conirol lers Free fully functional software Blank chip auto detect for super fast bulk programming Parallel port connection Supply 16 18Vde Assembled Order Code AS3117 24 06 ATMEL 891x11 Programmer Uses senal port and any standard terminal comms program 4 LED s display the status ZIF sockets Ue not included Supply 16 18Vde Kit Order Code 3123KT 24 96 USB amp Serial Port PIC Programmer a USB Serial connection Header cable for ICSF Free Windows software Wide range of sup ported PICs see website for T Complete listing ZIF Socket USB Plug A B lead not incl Supply 16 18 Vde Kit Order Code 3149CKT 34 96 Assembled Order Code AS3149C 49 96 Winning accolades the world over Easy PC for Windows V9 is another major milestone in the evolution of this extremely popular software tool Try a demonstration copy of Easy PC and prepare to be amazed at the power versatility and remarkable value for money a Fully integrated Schematics amp PCB layout in a single
142. must be content with selecting a suitable motor depending on the requirements of each application Classical designs In numerical terms the dominant technology is the iron core motor Figure 4 The rotor has at least three coil segments which suffice for most low voltage applica tions High operating speeds require a balanced epoxy potted rotor Around it separated by an air gap of a few tenths of a millimetre is the stator com prising a system of permanent magnets The motor housing completes the magnetic circuit like a return wire in an elec trical circuit The coil connections run to the individual commutator segments from where the current flows via sliding brushes generally made of copper loaded graphite also called carbon to the motor con nections The brush arrangement is the part most prone to wear and failure Its size reflects the power of the elektor electronics 2 2006 motor in high current motors the commutator also known as the collector is large and the wide brushes exert a high pressure in order to minimise voltage drop The whole system looks and behaves like a shoe brake Motors of this type require a high no load current just to overcome the braking torque The motor operates rather more economically at higher load when the external torque is several times greater than the internal torque Conversely smaller brushes exerting a lesser force c
143. national Ltd 373 Scotland Street Tel 44 141 429 2777 Glasgow G5 8QB Fax aa a 429 2158 United Kingdom E Mail 31 ftdichip com www ftdichip com With this issue we start selling our R8C 13 Starter Kit at a price you can t refuse just 8 30 plus P amp P If ever you wanted to get your hands on a ready made 16 bit microcontroller board with associated software tools on a CD ROM now s the time to grab yourself a bar gain For the benefit of our readers we ve been able to strike an exclusive deal with Renesas and their distributor Glyn for the distribution at very low cost of their R8C 16 bit microcontroller module That s right a module so there s no SMDs to solder or parts lost to mum s vacuum cleaner All you need to do is solder a normal size pinheader supplied with the kit This we re pretty confident most of you will be able to pull off Although supposedly we re test ing your solder skills the real reason the pinheader isn t on the modules is that it allows low cost packaging to be used You can start using your R8C microcon troller module straight away using the get u going examples in this issue Next month we will take the project one step further by mounting the tiny R8C module on a motherboard that not only unleashes the full connectivity in terms of port lines etc but also adds five or so add on functions like USB and a power supply The module being available at low cost through o
144. national Media Cambridge House Gogmore Lane Chertsey Surrey KT16 9AP England Telephone 01932 564 999 Fax 01932 564998 e mail gerryo husonmedia com to whom all correspondence copy instructions and artwork should be addressed 87 TNE i TEPFDAETARA ALE FRrreringerrined tannanaanaasana nd e Powerful amp flexible schematic capture e Auto component placement and rip up retry PCB routing e Polygonal gridless ground planes e Libraries of over 8000 schematic and 1000 PCB parts e Bill of materials DRC reports and much more Mixed Mode SPICE Circuit Simulation e Berkeley SPICE3F5 simulator with custom extensions for true mixed mode and interactive simulation e 6 virtual instruments and 14 graph based analysis types e 6000 models including TTL CMOS and PLD digital parts e Fully compatible with manufacturers SPICE models e Co simulate target firmware with your hardware design e Includes interactive peripheral models for LED and LCD displays PCB Layout MT Pee ee Pee a De S020 0ppencpen nn Proteus VSM Co simulation and debugging for popular Micro controllers e Supports PIC AVR 8051 ARM7 and BASIC STAMP micro controllers switches keypads virtual terminal and much much more e Compatible with popular compilers and assemblers from Microchip Crownhill IAR Keil and others abcenten a E o 2 ee oe a A 0 T
145. nd opamp is configured as a bandpass element Preset P1 050353 is used to adjust the circuit for maximum output voltage The measured spectrum is shown in Figure 2 The first and second harmonics are more than 80 dB down with respect to the 1 kHz signal The alias frequencies around 74 kHz are suppressed to the extent that it s difficult to prove their existence The circuit is quickly built on a piece of Veroboard Figure 3 In order to prevent ground loops it is recommended to power the circuit from a set of recharge able batteries Here four NiMH batteries are used In conclusion the simple battery powered 1 kHz generator described here can be built for less than three pounds It is free from complex adjustments preci sion capacitors and inductors The software to program into the microcontroller is available as a Free Download from www elek tor electronics co uk the file num ber is 050353 11 zip 050353 1 Note Although the AT90S1200 is no longer produced by Atmel it is still widely available from retail outlets like Reichelt Segor and Sander A successor type is available see Atmel s application note no AVRO93 Replacing AT90S1200 by ATtiny2313 pj z yo LM a ji si ata in m ni tS a A r Va Di Fh IE l I a i iy Ls al pl al aT S g oo Sot a p e ie 1 il elektor electronics 2 2006 RETRONIGS Jan Buiting Magnetism l
146. ne alternatives it would seem because a higher voltage does no harm However do keep an eye on the device size as the alternative may no longer fit the board Not all manufacturers produce every combination of value and working voltage because it often happens that a 10 uF 10 V electrolytic cap is just as large and has the same price as a 10 uF 35 V type When purchasing parts for use in out laboratory we purposely select devices with a relatively large size so that alternative brands will also fit the board we ve designed With just a few exceptions duly mentioned in the parts list electrolytic capac itors are now radial types 05031 5 1 69 HANDS ON VINTAGE OV Dynamo Rec For vintage motorbikes Ulf Schneider This bulletproof electronic regulator was originally designed to replace the troublesome original electromechanical regulator on the author s vintage BMW EMW R35 motorbike A large number of BMW EMW devotees have since successfully tested this unit on their machines without problem The design is universal and should be suitable for all bikes using the same switched earth field regulation method The author designed this regulator for his EMW R35 3 motorbike The bike was built by Eisenacher Motoren Werken EMW based upon the pre war R35 machine from BMW Produc tion of the bike continued for many years after 1945 This electronic regulator design uses semiconductor swi
147. ng the sta tor ring into an undulating shape A sinusoidal alternat ing voltage sets up standing waves In order to create a travelling wave the ring is partitioned into two or more electrically isolated and separately stimulated zones If sinusoidal signals are applied to the two zones with the same frequency but with a phase offset the standing waves superimpose to create travelling waves The gener ally cross shaped rotor the same size as the stator is pressed onto the stator by a spring such that there are always several moving points of contact Figure 5 The advantage of this high friction arrangement is that the travelling wave motor retains its position when power is removed dispensing with the need for a brake The rotor is driven round by the tangential component of the force from the travelling wave the greater the force the greater its movement The speed of the rotor can there fore be controlled by adjusting the mark space ratio of the drive signal a higher mark space ratio implies a greater displacement Practical motors from various man ufacturers achieve torques from 0 0003 Nm to 2 Nm with stator diameters from 3 mm to 90 mm Rotational speed lies in the range from 2000 rpm down to 70 rpm with operating frequencies from 650 kHz down to 42 kHz This type of piezoelectric motor is distinguished by its excellent dynamics Only small masses are being moved which allows for high acceleration Also at very low rotational
148. nging from video game soft ware to video game hardware with the unveiling of the XGameStation Micro and Pico Editions a revolutionary new 2 2006 elektor electronics way to learn about the hard ware that goes into building game consoles themselves The XGameStation Pico Edition XGS PE is a complete game development kit inspired by clas sic systems such as the Atari 2600 800 Apple Il C64 and Nintendo Entertainment System The XGS PE kit includes a kit complete with all the parts nec essary cables an eBook written by Andre LaMothe on the design and programming of the XGS Pico Edition along with all the software necessary to create your own games demos and experiments Armed with a complete under standing of how the system was built and operates users then create their own games or play games made by their peers The online community at www xgamestation com com pletes the system s appeal pro viding a place for XGameStation developers to share ideas soft ware and even discuss hard ware modifications The system plugs into any NTSC TV and supports vintage Atari 2600 controllers XGameStation Pico Edition s games and appli cations are stored on the internal processor s Flash memory allow ing users to develop and down load their games from a PC using the accompanying tools The official Website for the XGamesStation is www xgames tation com retid pr where you will find media downloads
149. ngth of A 565 nm Because a laser pointer transmits fairly nar row band light at 650 nm its photons have insufficient energy to generate current in a green LED The same applies to a yellow LED so The datasheets supplied with the E blocks CAN bus module include a short description of the basic CAN operation as well as pointers to further information available from the Matrix Multi media website There are also references to datasheets of the CAN controllers used on this board These include e AN713 Controller Area Network CAN Basics e AN215 A Simple CAN Node e MCP2515 datasheets An article on the E blocks CAN module is printed in this issue For background articles on the the two missing entries in the table last question should read O nA The value is confirmed by prac tical measurements A use ful overview of semiconduc tor materials and their bandgap energy values may be found at www tff uni kiel de matwis amat semi_en kap_5 backbone r5_1_4 html CAN bus and several projects published in pasty issues of Elek tor simply type Controller Area Network or CAN in the search box on our website homepage All articles returned by the search engine can be down loaded individually MailBox Terms Publication of reader s correspon dence is at the discretion of the Editor Viewpoints expressed by corres pondents are not necessarily those of the Editor or Publis
150. nnected to ground by transistor switches To 62 ensure that the two transistors are never conducting at the same time they are switched off faster than they are switched on The time when nei ther of the transistors is conducting is C1 C20 5600pF 2000V D1 D20 DSA1 18D 1800V 7A C15 C17 Figure 2 The schematic of the cascade stage is also standard called the dead time The disadvan tage of this arrangement is that each transistor must withstand twice the supply voltage when the other one is conducting because the two halves of d S 10000V 050192 12 elektor electronics 2 2006 the primary winding have opposite polarity In this case that means each transistor must be able to switch more than 160 V We chose an inexpensive transistor type the IRF640 for our experiments It has a breakdown voltage of 200 V a channel resistance of 0 18 Q and a continuous switching current rating of 18 A However if you find yourself blowing up MOSFETs too often in the enthusiasm of your experimenting and that s bound to happen you may want to try using the IRFB260N It is considerably more robust but it s also a good deal more expensive The max imum continuous current rating of the latter type is a hefty 56 A and that in a TO220 package and the maximum junction temperature is 175 C The channel resistance is also considerably lower less than 0 04 2 One drawback is that the input capac
151. o earth through the field coil reinforcing the field magnet ism and producing a higher output voltage and strengthening the excita tion field The armature output voltage increases as the rotational speed increases until it reaches approxi mately 6 5 V when the reverse current coil pulls in contacts 4 and 5 connect ing the dynamo output to the bike electrics including the battery The out put voltage continues to rise with increased rotation until the level at the voltage regulator coil is sufficient to pull the field connection contact 2 away from 1 earth Current through the field winding can now only travel to earth through the 6 Q wirewound resistor mounted on the dynamo stator Current through the field coil drops reducing the output voltage With increasing speed dynamo output con tinues to rise until the voltage at the regulator coil is sufficient to pull con elektor electronics 2 2006 julator tact 2 all the way up to contact 3 effec tively shorting out the field winding and reducing the excitation field to a minimum This process repeats 50 to 250 times per second and regulates the output voltage to around 7 V The reverse current coil consists of a few turns of thick wire wound in the oppo site direction over the top of the regu lator coil so that current through the coil reduces the regulator field At low speed when the dynamo output is less than the battery voltage the field pro duced by the reverse
152. ocontroller board Satellites e Simulation November Chipcards Protection December Electromechanical Enclosures Application Board for R8C The R8C 13 module used for the initial experiments in this issue may be small but it has a lot of potential However this can only be unleashed if you have a motherboard that opens up the full connectivity of the micro board The R8C Application Board described in the March 2006 issue offers two serial ports a USB connector a connector for an LCD module a stabilised power supply an array of LEDs and last but not least a handy prototyping area Versatile FPGA Unit Lots of digital circuits may be replaced in one go by an FPGA Doing so not only saves board space but also yields a speed increase when compared to discrete Also logic parts Unfortunately FPGAs are only available in SMD cases that are impossi FPGA basics ble to solder by hand especially BGAs That is why Elektor labs have developed a Microcontroller Development Kits multilayer FPGA unit that s supplied ready built and tested to you The module has E blocks Hexadoku Puzzle a powerful FPGA sporting lots of RAM and flash memory RESERVE YOUR COPY NOW The March 2006 issue goes on sale on Thursday 16 February 2006 UK distribution only UK subscribers will receive the magazine a few days before this date Article titles and magazine contents subject to change NEWSAGENTS ORDER FORM SHOP SAVE HOME DELIVERY j ec kt O
153. ojects written by some excellent contributors and staff writers So this let ter is not intended as a criti cism of the magazine more as to observe that a feature has disappeared without a word of explanation after being enjoyed for so long Please bring back our sup plement Pat Redway UK Thanks Ken Pat and other readers who wrote us on the same sub ject There are no longer 30 fll small circuits l j in the December issue because all 100 we produce in a year have been included in the Summer Circuits issue At 144 pages the 2005 Summer Circuits edition was the thickest issue of Elektor Electronics ever printed So we have not let our readers down and in fact have again published more articles in a year volume than any of our competi tors on newsstand distribution in the UK Starting in 1988 and ending in 2004 and only in the English language version of Elektor 60 70 articles from our annual stock went into the July August Sum mer Circuits issue and the remaining 30 35 into the December issue Due to central ized production and simultane ous printing of all four language editions of Elektor in 2005 we changed this to 100 articles in the July August issue thereby restoring an Elektor tradition in existence between 1975 the year of our first issue and 1987 The change was duly announced in the June 2005 magazine as well as in several news items on our website sorry if you mis
154. oltage of V less 300 to 400 mV on the gates of each N MOS FET Everything is operational Per fect You can then unsolder the pull up down resistors and solder the two boards All that is left to do is adda little bit of heat conducting paste to the MOSFET metal tabs add a small heatsink and wrap it all in a piece of heat shrink tubing so well done you could mistake it for a commercial pro duct One last important point for those who would like to make their own PCB layout it is absolutely necessary to separate wiring for ground lines and V of power MOSFETs from the rest of the circuit in order to avoid any pro blem of commutation noise Star wiring is therefore necessary In the current version of the Brushless Controller for R C Models some of the components are not required place has been reserved for future extension such as a regulation loop for example Consequently it is possible to omit the following components C19 on the power board which is in any case wired on the outside this additional capacitor may be needed for more heavy duty power stages as mentioned above Pull up resistor R1 on the SCL line from the unused EEPROM removed from the diagram but present on the 30 layout D2 R4 C4 K4 reserved for a second additional path to adjust a regulation loop for example not imple mented in this version of the software perhaps one day soon Implementation and opera
155. on chip ther mal regulation that decreases charge current in over tempera ture situations thus preventing damage to the device The charger also supports multiple regulation voltage outputs mak ing it an effective charging solu tion for different types of Lithium battery technology The device s 5 pin SOT 23 or 8 pin 2 mm x 3 mm thermally SmartProg2 now with USB The growing popularity of note book PCs and the absence of the parallel interface LPT port even on desktop PCs is the rea son for the gradual extension of the portfolio of Elnec program mers with types connectable to a PC through the USB port The first such Elnec programmer with the USB interface was BeeP rog SmartProg2 comes as the second one Thousands of sold SmartProgs were the argument for a modification of the type to make it connectable to a PC through the USB port instead of the LPT port The basis of Smart Prog2 s hardware is a 40 pin versatile pindriver and freely pro grammable voltage generators as well as the limitation of the logical high level which allow to support low voltage as well as true LV chips from 2 V up All supported chips with up to 40 pins are programmed in the base socket The traditional diagnostic POD for self testing is an ELNEC standard The quality hardware is comple mented by top software which as a standard supports all MS Windows operating systems from WIN 95 to WIN XP The latest version of
156. onduct simultaneously Unfortu nately in practice this IC does not appear to be sufficiently robust to fault situations and the IC is also the cause of the poor measurement results of the CDAMP amplifier Perhaps comparable ICs from different manufacturers are better behaved for example the MIC4102 from Micrel 100 V Half Bridge MOSFET Driver with Anti Shoot Through protection 050183 1 elektor electronics 2 2006 The HIP4082 9 AHB BHB DRIVER First something about the driver IC the l w eoi Arer HIP4082 from Intersil This H Bridge FET driver k IC can be used for typical frequencies and njans ens pz voltages and is suitable for PWM controlled motors switching power supplies and class D amplifiers The IC has an adjustable dead time and a disable input which when active forces DETECTOR ae mee all outputs to a low level The dead time is i fa ato ero pH erste prover the Me A le enol ee a z DELAY bridge from conducting at the same time part of the Shoot Through Protection The IC also has a protection feature that senses when the power supply voltage is too low The outputs have a reduced capability compared to other ICs from the same family HIP4080 81 so that the package can be smaller An additional advantage is that there is less interference from peak currents when charging and discharging the gate capacitance 050183 18 The IC uses a bootstrap circuit to drive the upper MOSFET
157. onics into the pic ture see the text box and the brush less motor controller project elsewhere in this issue Of the two halves of the magnetic system it is now not necessarily the electrical part i e the coil that has to turn In electroni cally commutated and therefore brush less or sometimes BL motors it is the mag net that turns Figure 7 This gives a smoother rotation than can be achieved using copper coils and speed stability is also improved now depending only on the quality of the bearings which are the only remaining mechanical parts prone to wear The first brushless motors delivered power at very high speeds meaning that a planetary gearbox needed to be attached The motor itself is of simple construction alll that is involved is a cylindrical central magnet with three potted coils around it and a laminated iron enclo sure to complete the magnetic circuit Figure 8 Since the ends of the windings are relatively large in this design of motor the devices are considerably longer 2 2006 elektor electronics Rotational speed rpm Stator and back iron Back iron laminated ATT WLLL LL 050321 15 050321 16 Tango 45 08 brushless motor Efficiency Rotational speed Motor voltage approximately 18 V Controller type Jazz 55 10 32 Motor mass 300 g Fae Z o e o 3 v c o gt c 8 Ww 30 35 Motor current A 050321 17
158. ons to an existing circuit or PCB layout as Gain control for Elektor DRM receiver Burkhard Kainka Adding automatic gain control AGC to the Elektor Electronics DRM Receiver March 2004 is a useful undertaking The original receiver was designed to have tixed gain for the strongest sig nals with some headroom afforded by the large dynamic range of the sound card Admit tedly weaker signals we would like to boost a little if only that were possible A gain control add on would be desirable provided its addition does not compromise the linearity of the receiver The extension pro posed here employs a home made optocoupler consisting of a superbright red LED and an LDR The construction of the coupler in an aluminium tube Figure 1 was taken from the Photoelectrical Oscillator PEO a Rejektor cir cuit shown in Mailbox Elektor January 2006 on page 8 The governing advantage of this LDR LED combination is the pure ohmic resistance of the LDR which guarantees low distortion In the DRM receiver the LDR LED assembly is inserted into the feed back path of the 12 kHz amplifier as shown in the circuit detail in Figure 2 The drive signal comes from a circuit contained in the box 2 2006 elektor electronics LDR aluminium tube black cardboard epoxy glue LED1 LED2 LED3 low current red LDR1 LDR2 1k 40k marked AGC this is an AGC amplifier copied from another Design Tip Au
159. people are aware that such a router is in fact a small computer with a proper operat ing system on board elektor electronics 2 2006 One of the cheapest routers that is currently available is the Sweex LB000021 This router is for sale for as little as 19 It is a low cost router that uses Linux for its operating sys tem Linux and a few other tools run ning inside the router are open source programs under the GPL licence The most important requirement of this license is that the source code used in the product has to be included with it The fact that the source code is openly available makes it possible for the router to be used in applications that weren t even considered by the manufacturer From the outside the device doesn t look special It is a small box with only six connectors a power input for the The router used here for modding can be bought for less than twenty pounds Very few people realise that there is an easily adaptable embedded system inside this little grey box supplied power supply an Ethernet socket for the cable from the ADSL or Cable modem and four Ethernet sock ets for connecting the PCs What can t be seen from the outside is that there are two other useful connectors hidden inside the router which have not been used by the manufacturer When we open the router which is easily done by unscrewing four cross headed screws from the underside of the case we can take a look at t
160. performance Microphone Phantom Power and Headphone Amplifiers Balanced unbalanced signal lines with extensive RFI protection Call today for free samples and pricing Tel 0870 901 0777 Fax 0870 901 0888 DESIGN GATEWAY www design gateway com PalmLogic II US 399 00 e Compact Logic Analyzer L116mm x W73 3mm x T3mm e High sampling rate 400 MHz 8ch 200 MHz 16ch 100 MHz 32ch e USB 2 0 high speed mode ai e 8MB memory storage e Bus Analyzer function e Multiple waveform windows e Waveform save restore DESIGN GATEWAY www design gateway com True PCI Starter Kit US 135 00 e PCI Development Kit e Based on 200 000 gates FPGA e Extension connectors for 72 pin 1 0 ANEA e Configuration support for JTAG and slave serial e Free PCI Core for Target Mode DESIGN GATEWAY www design gateway com Ethernet I0 US 115 00 e 8 bits embedded network microcontroller e 6 channels available for 10 bits ADC e Ethernet 10 BASE T 10 Mb Ethernet m e UART port RS232 RS485 Max Speed atl 15200bps as e 35 bits general purpose 1 0 e 500 bytes user area flash memory DESIGN GATEWAY www design gateway com VariClock US 163 00 e Adjustable clock signal synthesizer e 3 rotary switches for frequency setting e Standard DIP pin arrangement e Support both 3V 5V by on board regulator VC250M14P Frequency range 25 400 MHz Frequency setting 1MHzstep Ss DANBURY ELECTRONICS VC100M14P Frequency range 25 100 MHz ht
161. prevent it being erased when the PC is switched off and on again The problem seems to occur fre quently and postings in internet forums seem to indicate that the file is often subject to damage by viruses and Trojans E blocks and the CAN bus Dear Editor happened to read a bit about E blocks in the latest Elektor issue am interested in a CAN bus inter face for a different project Where h 6 626 10 34 joule second i e Planck s constant and c 2 997 108 m s i e the light speed in vacuum The bandgap ener gy is usually expressed in electronvolts where 1 eV equals the energy acquired by an electron when passing freely through a potential dif ference of 1 volt As an electron has a charge e of e 1 602 10 9 joule second we get eV ci E mi pe See Oe cee abe D 0 E Er P ry a d m een e 5 fry a Where do find a description of the SPI bus and the com mands necessary to communi cate via the interface As understand it E blocks can be ordered through your Readers Services department Peter Blackburn Corrections amp Updates l sc Analyser 2005 April 2005 p 34 030451 1 The parts list states a wrong enclosure this should be a Hammond type 1593YBK Erengy gap io 1 602 10 9 joule second Green LEDs may be pro duced from for example gallium phosphide GaP In that case the bandgap ener gy equals 2 19 eV corre sponding to a wavele
162. printing or on a bad photocopy So for the past 30 years or so we ve written 4kQ7 not 4 7kQ 4700Q or 4 700Q Capacitors These can be subdivided into three classes depending on their value The first group is formed by radial single ended ceramic capacitors with a value of almost zero pF picofarards to 1000 pF If no further indication is given they have to be able to withstand at least 50 V while the temperature coefficient is not an issue The typical tolerance in this group is enormous at up to 20 The lead pitch is usually 5 mm although 2 5 mm also occurs in RF circuits The second group has a value of l nF one nanofarad or 1000 pF to about 1 uF one microfarad For these we usu ally employ radial devices with a polyester dielectric and a tol erance of 10 The working LABTALK INFOTAINMENT Resistor SFRI5 Vishay BComponents 0 4W 250V 5 metal film axial Capacitor Vishay Components 1 pF8 50V 5 NPO radial mono cap ceramic Capacitor MKT Epcos 100nF 63V 5 polyester radial Decoupling capacitor Epcos 100nF 50V 10 radial leaded multilayer ceramic X7R Axial electrolytic capacitor 4yF7 63V Radial electrolytic capacitor 4yF7 63V voltage is again 50 V These caps are produced by many dif ferent manufacturers and are generally uncritical in the appli cation unless otherwise noted of course Our printed circuit boards allow polyester capaci tors with a lead pitch of 5 mm or 7
163. pulse width per period of the PWM signal but another solution is to just increase the capacitance While testing it appeared that increasing the capacitance from 100 nF to 780 nF an additional 680 nF in parallel prevent ed collapse of the signal on the top side as shown in the measurement of Figure 1 During the time that the output is low this larger capacitance is charged and then holds its voltage for a longer period This increases the requirements for the diode and MOSFET because of the charging current particularly when first starting up The board layout also becomes more critical with regard to peak currents and interference pulses that can wreak havoc with other parts of the circuit or the IC itself When you read the FAQ on the Intersil website you will notice that it is very critical to apply this IC properly and that many designers get into trouble To reduce the risk of glitches it may be necessary to add or increase the gate resistors In addition there are strong recommendations for the board layout and the MOSFETs have to be decoupled with 1 uF ceramic capaci tors A common problem is glitches that cause the bottom MOSFET to conduct when the gate capacitance of the upper MOS FET is being charged All of this makes us suspicious that the problems of the CDAMP could be related to the PCB layout even though the PCB used in this design is a multilayer one Crossover distortion in a PWM amplifier There is one more interesting measur
164. r is used to control the motor generating a 5 V to 8 V square or sine wave According to the manufacturer the controller should have a resolution of at most 1 kHz preferably 300 Hz a single pin output is sufficient The best choice is to use a microcontroller with builtin PWM function The squarewave signal must be amplified using two transistors and filtered using a coil to remove har monics from the signal sent to the device 3 At a frequency of around 79 kHz the Elliptec motor runs forwards and at a frequency of around 97 kHz it turns backwards The two partial movements are superim posed in a way that causes the elliptic movement to be backwards The optimum frequency can be determined by the control electronics for example by measuring the current consumption of the unit The speed of the motor can be controlled by adjusting the mark space ratio of the signal The motor delivers a force of between about 0 2 N and 0 4 N the step size is given by the manufac turer as 10 um One application for this tiny motor is in models Marklin have used the motor to slowly and hence realistically raise the pantograph in a model elec tric locomotive 4 Advantages A piezoelectric motor produces no magnetic field and can therefore be used in sensitive nuclear magnetic reso nance tomography machines Also piezoelectric motors move in very tiny steps The speed and power output of these motors is therefore limited but the micrometre sca
165. r recently introdu ced to the market and completely dedi cated to this type of application i 6 Ln T5 amp T4 ON T5 amp T2 ON T3 amp T2 ON The brushless motor Ti ATGON ipa T1 amp T4 ON Not very complicated a brushless motor is characterised simply by three coiled phases distributed along a sta tor and positioned across a rotor com posed of permanent magnets Manu facturers often state the number of pole pairs characterising their motors Applying current to the coils produces a magnetic field The secret lies in an appropriate sequence applied to three phases of the motor in order to induce mechanical rotation The three coils will allow us to produce a magnetic field in six different direc tions the induced coils and natural magnetic fields of the magnets tend to be aligned from this point to finally describe a complete rotation To do this you will need six switches which are in our application none lads other than MOSFETs in order to apply the sequence also known under the Figure 2 Alignment of the induced magnetic field for each of the six steps 2 2006 elektor electronics 23 RC MODELLING magnet movement Vpc 2 RC filter an i as voltage divider 050157 15 Figure 3 Voltages at the terminals of phases A amp C step 1 The control principle We can model the power stage with six switches operating at fixed fre quency PWM Pulse Width Modula
166. r DS1M12 and PS40M10 oscilloscopes have sophisticated digital triggering including delayed timebase and come with our EasyScope oscilloscope spectrum analyzer voltage and frequency display application software and our EasyLogger data logging software We also provide Windows DLLs and code examples for 3rd party software interfacing to our scopes DS1M12 USB scope Logger Our ANT8 and ANT16 Logic Analyzers feature 8 16 capture channels 2 x 1MS s Input Channels waveform of data at a blazing 500MS S sample rate in a compact enclosure generator output EasyScope amp EasyLogger s w included priced from 125 00 DS1M12 amp ANT8 p N 1 to 16 port USB to Serial Adapters DA a With over 16 different models available we probably stock the widest range of USB Serial Adapters available anywhere We offer converter cables multi port enclosure style models in metal and plastic also rack mount units with integral PSU such as the USB 16COM RM Serial interfaces supported include RS232 RS422 and RS485 We also supply opto isolated RS422 and RS485 versions for relaible long distance communications All our USB Serial products 7 are based on the premium chipsets and drivers from FTDI Chip for USB 2COM M superior compatibility performance and technical support across 2 Port Industrial USB RS232 Serial with wall Windows MAC OS CE and Linux platforms mount bracket and DC auxiliary output priced from 20 00 US232B LC
167. r price conscious PCB supplier EVAO Online price calculation Online ordering Online order tracking Online 24 24H and 7 7D Interested Contact us 32 15 28 16 30 E mail euro eurocircuits com for rapid context switching for example when interrupts occur and there are multi cycle instruc tions to speed up multiply divide and block copy operations All of Cambridge Consultants XAP microprocessors are sup ported by its xIDE integrated soft ware development and debug environment which includes a programmer s editor assembler debug interface instruction set simulator project build manager and GCC compiler which pro vides the path for programming in C xIDE is quick and easy to install and use on Windows PCs with Linux Unix and Mac OS versions also available xIDE can be customized to add features specific to a licensee s ASIC or ASSP and licensees can brand and deliver xIDE to their developers Other advanced technical fea tures of the XAP3 XAP4 and XAP5 include hardware support for operation as a slave proces sor when a master processor downloads a code image and bootstraps the XAP support for multi processor debug over SIF and architectures for combining XAP with Cambridge Consultants APE signal processing engine which offers a dynamic data path routing capability Details of the cores can be found at www CambridgeConsultants com ASIC including trial downloads of the xIDE soft
168. r to encourage you to investigate CAN we are making available an E blocks Easy CAN kit at 30 discount An offer you CAN t resist E blocks Easy CAN Kit Flowcode Professional 118 00 E blocks LED board C 14 65 2 x E blocks LCD board 38 60 2 x E block USB Multiprogrammer 154 60 E blocks Switch board 14 65 2 x E blocks CAN board 67 00 2 x PIC16F877 fe 24 1010 Total value 428 50 Special Offer 299 00 Ordering Use the order form at the back or go to www elektor electronics co uk E blocks will be shipped after receipt of payment Prices are exclusive of postage ius JACOB S LADDER Some people find electric arcs scary while others find them especially fascinating If you re not afraid of a few kilovolts and observe due safety precautions you can use the circuit described here for some interesting experiments However you must always remain alert and keep safety in mind because the voltages and currents generated by the circuit can have nasty consequences Ton Giesberts If you search the Internet for things related to high voltage you quickly encounter terms such as Tesla coil and Jacob s Ladder In its original form as invented by Nikola Tesla a Tesla coil is an air coupled transformer that works entirely on the principle of resonance and can easily generate potentials of several hundred thousand volts or even a few million volts At such voltages electric arcs jump ran
169. required modifications and return them to receive a firm quotation driver is compliant with the Microsoft Broadcast Driver Archi tecture BDA standard for Win dows This ensures optimum per formance and compatibility with PC software applications such as CyberLink PowerCinema There is no need for an external power supply because MicStickD fully complies with the USB 2 0 bus powered specification The MicStickD reference design comes complete with schemat ics Gerber files Protel design files a Bill of Materials BOM and driver software The BOM has been carefully optimized for low manufacturing cost MicStickD can be built for around 20 USD in quantities of 100K OEMs can add an enclo sure design of their choosing and go straight to production This royalty free MicStickD DVB T USB design kit is available now Product information on the DRX 3975D COFDM demodulator may be found at www micronas com products by_function drx_397yd product_information index html WWW micronds com 067016 1 All sizes can be supplied with an internal copper silver painted coating to provide EMC capabil ity typical attenuations are bet ter than 95 dB at 1 MHz falling to 46dB at 1 GHz All sizes can be moulded in many different materials and colours milling punching drilling and silk screen ing of both the enclosure body and end panels is also available IR ransparent end panels battery compartments and holders b
170. rge current of NiCd batteries on permanent charging to levels even smaller than 0 1 C So decided to have a go at my own DECT set The charger with the set looks a bit different and con sist of a current source built from a diode and a transis tor the latter supplying about 30 mA The batteries in the phone are 280 mAh types reduced the current to about 2 2006 elektor electronics 18 mA approx 0 065 C by increasing the value of the resistor in the current source The result flat batteries after about two weeks It then occurred to me that the phone itself also draws cur rent when placed in the charger pod So in my case the manufacturer did manage to design a proper charger Nico de Vries Netherlands A valid point Nico that should be taken into account when dimen sioning the charge current Thanks for letting us know Elektor Year Volume CD ROM problems Dear Jan am unfortunate ly unable to install the Elektor annual CD ROM After running Setup get the error report 16 bit Windows subsystem C winnt system3 2 autoex ec nt System file unsuitable for ms dos and Microsoft applications Next when run EASETUP EXE something is being installed and am informed that the installation is successful However when starting the Archive program once again get the above error report telling me the system file is unsuitable am using Windows 2000 Professional Can you help please
171. rms Microphones Spark production gas lighters Inverse piezo effect voltage to pressure Resonators and sound Ultrasound sources liquid level measurement flow rate measurement etc 5 Piezoelectric loudspeakers Frequency references quartz crystals ceramic resonators Ceramic filters Piezo actuators Micropumps Injection nozzles inkjet printers chemical analysis etc Active damping systems Consumer electronics see text Piezo motors Autofocus lenses Sliding stages microscopes medicine tools etc Modelling Other applications still under development References and links 1 www piceramic com piezoeffekt html 2 www piceramic com technologie html 3 4 5 6 www elliptec com http www siemens com index jsp sdc_p d1 187140 i1184346lmn118410101184346pFEcfs5u20z1 amp sdc_sid 32992667905 amp www physikinstrumente de products section7 piezo_motor_index htm www piezomotor se 7 Dynamics of Ultrasonic Motors Thomas Sattel dissertation Darmstadt 2003 37 HANDS ON MICROCONTROLLERS as Wher A I i i i O10Hd A CENE E ETET Am g i Tej i ib alae a f t a ik et i g r aa ware am i La 0 Gunther Ewald and Burkhard Kainka Thanks to the efforts of Elektor Electronics and Glyn for the first time now a European electronics magazine supplies a complete microcontroller starter board and accompanying
172. rochip com MCP7383 1 067016 5 satile programmer as well as those who find BeeProg too powerful and therefore unneces sarily costly In circuit program ming through the ISP connector may therefore be the decisive argument for SmartProg2 becoming your favourite More information at www elnec sk 067016 7 15 OTTA vc moros The Quiet Revolution Using electronics to make the almost ideal DC motor Ludwig Retzbach Electric motors are impressively simple and efficient Whereas even the most modern diesel engine might have an efficiency of no more than 45 a modern DC motor can achieve a figure as high as 98 This is accompanied by extremely high torque excel lent power to weight ratio good reliability and comparatively low cost Following extraordinary developments in the field of electric model aircraft the special qualities of DC motors have also led to their increasing use in hybrid vehicles Unfortunately the perfect mobile power source still needs to be invented before the steam engine inspired internal combustion engine can finally be consigned to the museum elektor electronics 2 2006 When efficiency figures rise to within a few percent of the magical 100 value minds will no doubt fill with doubts and thoughts of perpetual motion machines But there is no need for concern here physics is on our side And it will not come as a surprise that the automo tive industry is also turning to
173. rollers have the CAN controller embedded i e on chip which reduces the cost of the I O circuitry nearer node These devices can be seen on the image of the EBO18 E blocks board shown in the introductory pho E tograph You can see that the connections to the CAN Figure 2 065030 12 node are Power Ground CAN H CAN L and then other A Typical CAN node connections to I O as required In order to understand how CAN works at a higher level let s consider Figure 3 which shows some of the possi ble CAN nodes in a car In this context where a node is a complete functioning unit the node is often referred to as an Electronic Control Unit or ECU Here you can see five ECUs an engine temperature sensor an instrument panel a switch on a brake pedal and ECUs for the left and right hand rear light clusters Although the wires are not shown here all power and grounds are connected and all CAN H and CANLL terminals are connected by Engine temperature sensor Rightrear lightcluster Indicator Reverse instrumentpanel oe a 100 ohm terminated twisted pair wires In practice you lightcluster Gi may find the foot brake connected to the instrument panel Figure 3 838 ECU etc but for illustrating how CAN works let s just Example of CANbus 2 2 assume t
174. ronics s2 lt s2iesovarexad www lichfieldelectronics co uk 44 London Electronics College Showcase www lec org Uk 000 ccc eee eee 81 MQP Electronics Showcase www mqgpelectronics CO UK 81 New Wave Concepts Showcase www new wave conceptS cCOM 81 Newbury Electronics www newburyelectronics co uk 73 Number One Systems WWW NUIMDEFONE COM 1 wees 33 Nurve Networks www xgamestation com 00 eee 73 PCB World Showcase www pcbworld org uk aa nananana 81 PICOS aye 2 SUS Stn assed Gass eee A www picotech com nie ou g 8 oes wee S484 es 33 Quasar Electronics Showcase www quasarelectronics cOoMm 32 81 Robot Electronics Showcase www robot electronics cO Uk 81 SNOWCASE gues duet a8 yee aur E eee aoe sages dag ace ad oe eh doe E eee 80 81 SK Pang Electronics Showcase WWW SKPANG CO UK 0 eee 81 Sytronic Technology Showcase www m2mtelemetry COM 0 0 00 cece 81 Ultraleds Showcase cis cuwsacaueass www ultraleds co Uk nce twecawe ta ceswednd 81 USB Instruments Showcase www usb instrumentS COM 81 Virtins Technology Showcase WWWVINS COM cua cassie etesaawen aes 81 Advertising space for the issue of 14 March 2006 may be reserved not later than 14 February 2006 with Huson Inter
175. rts lists printed with con struction articles in this maga zine most components lack an exact description That s not only because the application is not particularly demanding in respect of component ratings but also because we assume that you the electronics enthusiast know perfectly well what we mean However many less con tident readers have problems deciding which parameters are tight and which are fairly loose Resistors We normally use resistors speci fied at 0 25 watts 5 tolerance and a maximum working volt age of 200 volts Of course you are free to use better specified components like metal film resis tors 2 or 1 close tolerance or types rated for 250 V or 300 V The same for the power dissipation specification 0 33 watt or 0 5 watt will also tine as long as the relevant com ponents fit on the board A specific problem with resistor values comes from the fact that different systems for number notation are used throughout the world A number of countries on the European Continent use a comma rather than a point for the decimal separator Because Elektor is read all over 2 2006 elektor electronics the world we needed to solve the problem and did so by omit ting the separator altogether printing the k for kilo or M for mega in its place As an added advantage it improves the general legibility as a deci mal point or comma may eas ily disappear with poor
176. rument cluster wants to know what the temperature of the block is so temperature can be displayed on the instrument console and if necessary the warning light acti vated The designers of the system will have decided that the temperature needs to be monitored at say five sec ond intervals So every five seconds the central console will issue a message saying can anyone tell me what the block temperature is The ECU on the block is pro grammed to look for the message can anyone tell me what the block temperature is to then measure the tem perature and reply with a message stating the block temperature is followed by the temperature data A key problem Having understood the basic principles behind CAN the next question is exactly how is the basic message struc ture used to communicate all this information Here is a key difficulty of CAN Whilst the general CAN methodol ogy the electrical connections packet structure error cor rection and low level software are fully specified all the rest is left up to you In practice this has meant that every automotive manufacturer has chosen their own propri etary protocols Massey Ferguson will be different to Audi will be different to BMW and so on The reason for this is probably twofold firstly automotive companies don t want unauthorized people tapping into the bus that manages all the safety critical electronic devices in the vehicle and s
177. rysial Radio Standard Solar Kii Light Semsar and Kelas Baboni Electronics Books Ded rend tec rbot toe Anaie Abie Natko Hadi Fiam Hafield ik Projects fer Hadia Amaira PUSS simple indoorwindow arriak IS simple tropical WLW Aerials Frojeets fer yiabew Fnthesiasds Practical Munic Pirapects Fractical Fiher oplig prupects Fractical Opdo Flectreni propectal4 95 Electronic Projects for the garden 4 94 44 simple VT Block projects 4 4 J S55 Frojirti 4 Power Sapp Projects 4 Test bqeipment i ansi ruri jeen Cipin isie TiTlock propects Practical bscallanor breuin Cell digs and constrection 30 IC Terminal Bleck projects 4 Project Building for begineers fb How to Theis and Make Ps 4 50 4 95 LLH Beginners gide te TH Ha Begingers geide te CMOS i s i Amar AM irromp PS CY Aver AiD hot sir gun DELY Anyer 94 irma tr Amer WA PSU amp clamp 27 Arar brow Tipa from EITI Aste PH free solder M 1 99 Aste PR fret colder dl EIF Amies PB free colder 18M 07 0 Blackspur WOW jron opper lirakl 4 EIF Featured Item We Also sell VAN carbon pester WY mel peer Si UW Gore eae aA URIS SMI pesision 0 25 corbon Pots j1 W carbon Pets I hermiokirs et ranpe of diig 4 range of diaii PaO range of diodes mijd diode p IN4146 diode Jp Bridge Hewlolicre LAW finns PHO SW emr i F l pin melay Power connectors DIS Plugs sockets IP Socke memory sackets LSE sacke
178. s are combined here the first used to start up the motor is a sam pling when the PWM gate command signal is OFF method patented by ST Pins 10 to 12 are then directly connec ted to phases via resistors R10 R12 and R14 outputs PDO PD1 and PC3 are left in high impedance and the sampling occurs at each PWM pulse as is shown in Figure 6 This method allows for increased sensitivity because the zero crossing signal is not attenuated by any resistor divider When the motor reaches sufficient rate the sampling occurs during the ON time of the PWM Outputs PDO PD1 and PC3 go to low state and the PWM signal then returns to a level that can be understood by the micro via divi ders R10 R11 R12 R13 and R14 R15 The reference voltage used becomes external present on PBO Figure 7 shows the oscillogram of the unenergi sed phase High frequency sampling 1 MHz during the ON time of the PWM makes it possible to achieve a ratio of 100 and guarantees a maximum rate no phase delay due to using RC networks as in traditional setups The power stage We opted for an entirely discrete approach as the diagram in Figure 8 shows in order to make the setup accessible We did not want to use specialised integrated circuits to control the power MOSFET gates The driver designs were not easy because the specifications call for a variable power supply voltage of between 5 5 and 20 V and require utilising synchro nous rectification se
179. s can be wired in a star or delta arrangement 21 RC MODELLING Florent Coste Brushless Motor Controller Speed control for radio controlled scale models This article mainly concerns enthusiasts using radio controlled scale models that include an electrical motor without permanent magnet brushes usually called brushless motors 22 elektor electronics 2 2006 Main features e Input voltage 5 5 to 20 V e Current 18 A e Phase advance independently adjustable for min amp max speeds 0 to 30 degrees e Soft start Active braking Throttle calibration e BEC can be disengaged and released amp choice of battery type 6 to 14 NiMh NiCd cells automatic detection of 2 to 4 LiPo cells e Adjustable PWM frequency 12 24 48 kHz e Buzzer mode loss of receiver signal name of trapezoidal method cf the the coils during these six steps and shape of the motor current waveform the resulting mechanics are shown in Figure 1 shows the current induced in Figure 2 massive inter est in recent years for this type of propulsion system has made it possible to take electric motors windings A B and c to record levels in terms of efficiency and compactness with the inevitable trade off of increased complexity in control electronics This article descri bes the basic theoretical principles lin ked to the operation of these motors and a solution that is dependent on the ST7 microcontrolle
180. s in cooking salt the charge movements on average cancel out over the entire crystal and the sub stance consequently exhibits no piezo electric effect 2 2006 elektor electronics a doubling in pressure corresponds to a doubling of the electric field In other words the ratio between the mechanical pressure and the electric field is a constant The constant depends on the direction of the pressure and the direction of the field since there are three spatial dimensions for each quantity there is a total of nine constants in all Also shearing motions can produce an electric field so that for a full description of the piezoelectric effect for a given substance a total of 18 constants must be specified dp dh db db ob dh oh eh 050375 11 35 Figure 3 The sliding stage shown is moved using a piezoelectric drive Source Physik Instrumente PI GmbH amp Co KG Figure 4 This piezoelectric motor driver kit from Trinamic offers four output signal channels Source Trinamic Figure 5 Diagram of a travelling wave motor Exposed on the right is the stator whose segmentation can be clearly seen Source Ref 7 MOTORS Gerson i pinn apr roo parami lira siaior RSS rra g Another application is in the field of consumer electron ics Thomson make a rear projection television where a piezoelectric actuator moves a mirror in the light path rapidly to and fro to move th
181. sed these am pleased to say that we had an encouraging amount of positive feedback in response to the return of the 100 items version of the Summer Circuits issue The change was rewarded with newsstand sales figures nearly 10 up as compared with the previous year Besides articles in good Christ mas spirit the December 2005 issue contains four major con struction articles and three design tips which hope have kept many readers busy over the Christmas holidays WET MAILBOX Solution to the December 2005 problem p 78 LEDs detect light Quizz Away Very few correct entries were received for this the last problem in the series Einstein received the Nobel Prize for Physics for his research work on the pho toelectrical effect which was actually the subject of the December 2005 prob lem For a current to be generated in an LED in response to illumination with visible light one con dition has to be fulfilled the photon energy must be sufficient to overcome the so called bandgap No measurable current is gen erated if insufficient energy is presented The number of electrons freed is pro portional to the light current generated The energy W held by the photons is relat ed to the wavelength A as in l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l l i W hc amp replace the existing file Next make the file read only to
182. ship between speed and torque does not hold for higher pole counts Greater spacing is required between the poles which implies that they need to be arranged in a larger circle see Figure 12 So as not to increase the size of the enclosure the design is turned inside out thin permanent magnets on the outside thick electromagnets the coils on the inside The result is a so called external rotor see Figure 13 One useful side effect of this arrangement is the greater leverage that the force pro duced between stator and rotor has on the output of the motor which increases torque still further The exterior of the motor can no longer be held fixed but there is the advantage that the magnets turning along with the exte rior part of the enclosure are better cooled and therefore less likely to overheat when the motor is overloaded Multi pole exterior rotor designs with their exceptional torque are pre eminent among electric motors and strike terror into the hearts of gearbox manufacturers If a gear box is required it is essential to ensure that it can with stand the torque the motor is capable of producing A disadvantage of the exterior rotor design is that it is harder to cool the stator which now lies in the middle of the motor Copper and iron losses have to be managed and there is less space for the windings The main appli cation area for this type of motor Figure 14 is there fore where brief or intermittent bursts of
183. software running on the PC taking into account that large signal level differences may occur Using an AGC automatic gain control circuit we achieve the best possible signal level applied to the sound card under all receive conditions Particularly with extreme fieldstrength varia tions due to fading etc an AGC guarantees fewer hiccups in the decoding process The DRT1 receiver from Sat Schneider www satschneider de already has an input for gain control Using the VGC_IN terminal on the receiver the gain may be con trolled with a slope of 25 dB V With the Elektor Electronics DRM receiver AGC is also fairly easy to install as an upgrade see the rel evant Design Tip A control amplifier for DRM needs to comply with some spe cial requirements to make sure the signal is not corrupted Fast level changes in particular must be avoided The circuit pre sented here accepts the 12 kHz IF signal from the DRM receiver and turns it into a control volt age The first stage is a half wave rectifier At first blush it FBI siren with flashing light Arthur Schilp This ultra simple circuit will pro duce the familiar sound of sirens used by US police cars on emer gency calls A small lamp will also flash syn chronously with the siren sound The circuit is capable of pow ering loads greater than 1 A for one or more lamps or a pow erful loud speaker the kit producing quite a bit of noise and light The circui
184. t When assembling the board ensure that R7 and R8 are placed sufficiently distant from the board to provide adequate cooling 64 elektor electronics 2 2006 o transformer is a bit fiddly Construction Small bends must be formed in the Fitting the components to the main cir leads of transistors T5 and T6 so they cuit board should not present any can be fitted to heat sinks After that problems see Figure 3 and Figure 4 the transistors should be attached to However fitting the leads of the DIY the heat sinks using insulating wash ers Solder the heat sinks in place first followed by the transistor leads As R7 and R8 generate a considerable amount of heat they must be fitted spaced above the circuit board Try to maintain a clearance of 1 cm If they Figure 4 The prototype Despite its moderate dimensions this circuit delivers around 200 W at 1000 V We tried to keep the circuit as simple as possible to make DIY construction reasonably easy COMPONENTS LIST C9 100nF 100V MKT C10 C11 1000uF 100V radial max Supply board diameter 18mm C12 C15 47nF 250V MKT F l l l l I Resistors p RI 12kQ Inductor p R2 R4 120 L1 10uH i R3 R5 332 R 470 5W Semiconductors l RZ R8 3302 10W D1 D2 BY448 l RO 6kQ8 D3 zener diode 10V 1 3W l R10 4702 5W DA zener diode 15V 1 3W I Pl 25kQ preset D5 LED low current l D6 1N4004 I Capacitors D7 D10 BY329 1000 yp Cl 150pF T1 T3 BC337 i C2 C4
185. t diagram of the electronic regulator 71 HANDS ON VINTAGE MAXIM MAX921 GND 050241 13 Figure 3 Block diagram of the MAX921 low power comparator Figure 4 SMD components ensure a compact PCB COMPONENTS LIST Resistors SMD case 1206 R1 6kQ8 see text R2 R5 4kQ7 R3 100 R4 1IMQ5 R SO5K20 varistor Capacitors SMD case 1206 C1 4nF7 C2 3pF3 ceramic multilayer Semiconductors D1 1L4148 D2 D3 zener diode 5V1 SMD D4 zener diode 9V1 SMD D5 EGP50D D BYV32E 100 TI BTS115A IC1 MAX291 PCB ref 050241 1 from The PCB Shop 72 reverse current actuator in the original regulator circuit VaristorR6 protects the FET drain con nection from any high voltage spikes that may be present The BTS115A TEMPFET has a very low ON resist ance and contains a non destructive device shutdown mechanism when the case gets too hot Diode D6 can also benefit from this if it is thermally coupled to T1 for this reason they should be mounted as close together as possible on the heatsink Excessive heat in D6 will also trigger T1 to shut down and protect the regulator Putting it all together Figure 4 shows the regulator PCB assembly Lack of space inside the dynamo casing means that some SMD components are needed for the design Electrolytic capacitors have poor relia bility at high temperatures so a multi layer ceramic capacitor is specified for C2 Th
186. t is built from two astable multivi brators in this case the familiar 555 of which two are present in an NE556 case Of course you are free to use two 555s if 4V 412V that suits you better Both timer ICs are configured to operate as astable multivibrators The first timer is configured with R1 R2 and C2 to supply a rec CV1 050094 11 would appear that a diode is missing The rectifier operates as an amplifier with output signal range limiting Positive half cycles are amplified about 10 times At the negative half cycles however the output volt age is zero because the LM358 operates from a single 5 V sup ply rail hence cannot supply drive in the negative range The tangular signal of about 2 Hz at pin 9 The lamp is switched on and off by way of power transis tor T1 The second 555 is config ured using R4 R5 and C5 and J D1 La1 1N4001 a 4 12V T1 K BD135 S y LS D2 J T2 8 32 Q OUT1 Mik K ee BD135 ak 7 050349 11 upshot is that we have a very basic half wave rectifier that s not hindered by any threshold voltage as usual from diodes The rectifier output signal is applied to an inverting integra tor An average direct voltage exceeding 0 5 V at the input causes a falling voltage at the integrator output a smaller volt age a rising output voltage The complete regulation loop consist ing of the gain control in the DRM receiver and the g
187. t it s all about The electric motor is a transducer which converts electric power P n the product of voltage U and current I into mechanical power Pou which can be calculated by multiplying angular velocity by torque t The effi ciency n is calculated as the ratio between the output power and the input power Power loss is the difference between the input power and the output power Figure 1 this power is not strictly lost but rather con verted into heat This dissipated heat warms the internals of the motor which reduces its efficiency further as the resistance of the copper increases Ultimately this can lead to overload and thermal failure with temperature sensitive magnetic materials this can occur at between 120 C and 150 C Good efficiency is of fundamental importance to electric motors not just in the interest of better use of energy but also in the interest of longer operating life Two motors of equal size one with an effi ciency of 80 and one with an efficiency of 90 although differing in efficiency by only 10 differ in power dissipation by 50 The maximum power that can be converted by an electric motor is also chiefly dependent on its efficiency Forced cooling systems such as built in fans can of course be added but these make the motor more complicated They also consume power even when they are not actually needed such as under 2 2006 elektor electronics Rot
188. tal puppets a number of Renesat FLASH draai Sakasi thia devica pou with io ube ath thie proged honi tha Bai 1 Select O TD rrine E uti mid Procol Kamei Path Aes erbek C Piega A eee FD i ere oo Ei Fols emisiied C Pispa A ere A a ere i a i Figure 6 Selecting the microcontroller type and transmission protocol 42 absence of any sour notes coming from the speaker the internal RC oscillator is fully adequate for this task That means you could flash the program into an R8C 13 connect it to a piezo electric speaker and a 3 V button cell and hang it from your Christmas tree or insert it in a Christmas card Now that you know the hardware is OK your fingers are probably itching to start programming something aren t they OK it s time to start up the integrated hardware development environment HEW In order to keep things fairly simple at first let s start by making a few changes to an exist ing project We ll also work without the debugger to start with High C You can use HEW to generate assem bly language projects However pro gramming the R8C in assembly lan guage is significantly more difficult than programming it in C because there are so many different data for mats and addressing modes The C compiler looks after all that for you You don t even have to know whether the microcontroller is processing a word a byte or a bit In this case C is easier than assembly langu
189. tches instead of the unreliable electromechanical regulator Vintage purists may dismiss the modi fication as non original but the origi nal unit was always unreliable and notoriously difficult to set up adjust the regulator under no load conditions and the battery becomes drained when the machine is driven with the headlight on which these days is essential Adjust the regulator under load and the battery boils up when the engine is run with the lights off The electronic regulator goes a long 70 way to solving this problem The design is suitable for all 6 V dynamos with a rating up to 75 W where the field coils are switched to ground The regulator draws less than 250 UA quiescent current A potential divider network allows the terminal charging voltage to be adjusted to suit the type of cell fitted to the bike Table 1 The regulator exhibits a temperature coefficient of approximately 7 mV C which is closely matched to lead acid battery characteristics The original A diagram of the original regulator cir cuit is shown in Figure 1 With the dynamo at rest the reverse current switch contacts 4 5 is open and the wiper of the field current switch 2 provides a path to earth for the field winding through contact 1 When the dynamo begins to rotate there is suffi cient residual magnetism in the field cores to ensure an induced voltage in the rotating armature coils This volt age finds a path t
190. that the diodes are oriented in opposite directions 66 elektor electronics 2 2006 Alternatives A collection of alternatives is described at htto www geocities com CapeCanaveral Lab 5322 hv2 html For example neon lamp transformers microwave oven power supplies and ignition coils can be used for a Jacob s ladder Besides Jacob s ladder applications this site describes other high voltage projects and supplies An example is making your own high voltage capacitors Leiden jars Several high voltage projects are also described at www uoguelph ca antoon circ hv hy html The www teslamania com has spectacular photos and film clips of high voltage perils The operation of the quarter shrinker is also described there That s certainly entertaining reading Additional designs and photos can be found at www richieburnett co uk tesla shtml That site also gives considerable attention to the theoretical background of generating high voltages If you still have an appetite for more have a look at http tesladownunder iinet net au index html There s also a lot of experimenting going on down under Besides demonstrating high voltage applications this site shows several other remarkable phenomena such as fer romagnetic fluids and other magnetic gadgets illustration courtesy of Resonance Research Corporation www resonanceresearch com The cascade circuits are suitable for use with all values in this pro
191. the CD First you have to select whether you want to install the Japanese ver sion or the English version Most of our readers will probably prefer the English version The program suggests C Program Files Renesas as the default installation path You should con firm this path A second default path is shown for the tool chain C Renesas NC30WA V530RO2 You should also accept the default path name as well as all subsequent default path names At the end of the installation an individual site code is dis played You can ignore it because it is only necessary for registering the software If you purchase the full version of the compiler you will automatically receive a CD with your own 2 2006 elektor electronics E you to keep your soft Our R8C starter kit is available now you can get going code for enabling the software After you have installed the HEW you have to run the installer for the AutoUpdate program As shown in the figure con firm that you wish to Configure ay receive weekly updates from the Renesas Tools website That enables ware fresh all the time If the PC on which your software is installed does not have access to the Internet you can cancel installation of AutoUpdate without causing any problems The most recent update file is on the CD and it must be installed next Atter being installed the updater immediately checks to see whether there is anything new and auto
192. the Vys threshold Of the P MOSFET with a gain and capacity in high current guaranteeing impeccable OFF and ON positioning of the power transistors no matter what their tem UBATT UBATT UBATT UBATT UBATT UBATT 050157 12 perature Relating to type N MOSFETS a simple gate pull up to the power supply voltage is performed using BC817 and the OFF setting is directly exercised by the small MOSFET at dri ver input T22 Therefore a complete push pull stage is not necessary in this specific case and we have more than the Viorwarq Of the BAT54C diode which is interposed between the T22 drain and the MOSFET T28 T29 gate One more thing on the network of resistors and diodes in the power MOSFET gate D4 R39 for example In order not to overload the power supply and to avoid any risk of short circuiting the branch cross conduction the MOSFETs of the same branch then 27 RC MODELLING PWM OFF N 050157 19 Figure 9 Current during PWM ON and OFF conduct at the same time which can cause a short circuit and in general destroy the transistors it is imperative to prioritize a very fast OFF setting and a slow ON setting In this way the BAT54C diodes allow for a very fast pull up down to the power MOSFET gates to 0 or Vbattery according to the type N or P of the MOSFET while the ON setting is at 240 Q R37 for K11 aN l Kr JP3 o 050157 1 oo0oo0ooogd aetna m Le o D3 EEF
193. the applied voltage varies at the reso nant frequency of the sample which depends on its elas ticity and its dimensions This technique is employed in quartz crystal oscillators where a block cut from a very pure quartz crystal in the right direction forms an exceptionally precise and stable RF frequency standard Actuators Among applications of the inverse piezoelectric effect we distinguish resonators from actuators and motors Actua tors move by a few micrometres when a DC voltage is applied This movement can be increased using a lever sys Figure 2 A piezoelectric valve in a diesel injection pump The grey piezo actuator at the right moves the needle in the nozzle Source Siemens VDO tem or by arranging a series of actuators in a stack Com plex motions can also be realised using cunning physical arrangements and wiring of multiple actuator elements One example application is the micropump capable of pumping a few nanolitres to a few microlitres of fluid Such devices are used in inkjet printers and in chemical analysis applications The piezoelectric actuators in mod ern direct injection diesel and petrol engines resemble a valve A pressure of up to 2000 bar is built up by a stack of piezoelectric elements Figure 2 moving a needle inside a nozzle When required a tiny drop of fuel a few microlitres is injected into the cylinder Because of its high speed it is immediately whisked into a combustib
194. the electric motor with hybrid technology Indeed the electric motor has already made more progress than many realise already the first race has been won by an electrically powered vehicle A modern vehicle although not usu ally electrically powered will nevertheless have a starter steering cooling system electric windows elec tric mirrors powered seat adjustments ventilation and suspension control all driven by electric motors This list is far from complete a fully equipped lux ury car will have well over a hundred invisi ble DC powered helping hands driving demand for greater efficiency and lower weight Although in a comparatively less advanced state of development the situation has been similar in model aircraft technology for some time The might of the DC motor is pitted against the force of gravity in electric aircraft under F5B com petition rules where a two kilo gram model aircraft can be cata pulted vertically into the air at 80 metres per second The power consumption of these motors which have a mass of around 300 grams can be nearly four kilowatts Although some might dismiss these hobby activi ties as frivolous they have in fact acted as a pacemaker for other more down to earth applications Any DIY fan will appreciate the increased productivity that comes from having a convenient and light cordless screwdriver a benefit of powerful and low weight motor and bat tery technology Wha
195. the software is available on our website www elnec com free of 2 2006 elektor electronics charge of course SmartProg2 supports more than 10500 pro grammable circuits February 2005 and their number is con stantly growing SmartProg2 is controlled by a status automat based on a pow erful FPGA circuit and it sup ports communication with a PC through the full soeed USB 2 0 interface so the programming of efficient DFN package enables smaller smarter charger designs for a variety of portable devices such as Blue tooth headsets MP3 players and digital cameras The thermal efficiency of the DFN package also allows high charging cur rents of up to 500 mA for faster charging Microchip offers the MCP73831EV Evaluation Board tor 45 to support the develop ment of battery charger applica tions using the new MCP73831 circuits is very fast Its reliability is enhanced by the classic ELNEC designed metal casing The dust cover of the ZIF socket supplied as a standard and a rubber pad under the socket s lever protecting the program mer s surface against damage speak about the sense of detail SmartProg2 s target segment is the customers who require a ver Miniature Fully Integrated Charger charger This board is available today at http buy microchip com The MCP73831 is available today for sampling and volume production For additional infor mation on the product see www mic
196. the two conductors or electrodes the voltage on the capac itors drops to a lower value That causes the arc to be briefly inter rupted which allows the voltage on the capacitors be built up again That creates a repetitive effect As already mentioned R7 and R8 limit the short circuit current That brings us to the snag the transformer which is nearly ideal turns out to be the problem Too much heat is dissipated in R7 and R8 in order to maintain an arc and there is even a chance that the transformer may become overloaded If that happens the core will be driven 63 JACOB S LADDER into saturation and immediately create a short circuit and T5 and T6 will be dead well before fuse F1 blows It s thus a good idea to choose a distance between the electrodes that causes a prudently repetitive arc bear in mind N N r Sercv oy Q S the rule of thumb of 10 kV per centime tre That still provides a nice effect and besides nice blue sparks it gener ates a considerable amount of noise and unfortunately a good deal of ozone That means your experimenting Am le DOO aliel J Ca te lt d Do D 22 3 NNA AG DE Vi Ama area must be well ventilated The main circuit should preferably be fitted ina well earthed metal box with forced air cooling in order to dissipate the heat generated by R7 R8 Tri and the heatsink for T5 and T6 Figure 3 The main circuit board is reasonably compac
197. tion The most appropriate spot for the controller is in a ventilated part of the scale model if possible This obviously depends on available space An instruction manual that may be down loaded from our website will help you configure the controller At the least you must have calibrated the throttle for the initial tests Modellers will reco gnize traditional configurations for this type of circuit like active braking soft start to gentle start for example elec trical helicopter rotors choice for PWM operating frequency configuration for battery type We have however opted for a 2 point adjustable phase advance see instruction manual allowing us to have a linear variation dependent on the throttle position between mini mum and maximum motor speed it is actually generally preferable to have soft timing 10 15 degrees for exam ple and more aggressive with hard timing 25 30 degrees If your motor is operating at a high electrical frequency please note that it is better to have a high PWM fre quency 24 or even 48 kHz For exam ple for a motor rotating at 20 000 RPM having eight pole pairs we obtain a commutation frequency of 6 commu tations per electrical cycle 8 pole pairs 20 000 RPM 60 16 kHz In order to guarantee a minimum number of PWM pulse widths between each commutation it is better to use an ope rating frequency of 24 of 48 kHz Rela ting to overheating of the power
198. tion allowing us to describe six dis tinct steps during which two of the three phases are excited We ll call voltage at phase B lai gt t demagnetisation commutation T1 T4 T1 T6 050157 16 Figure 4 Demagnetisation of the phase being observed 24 passing from one step to the following step commutation 1 2 2 93 3 4 4 5 5 6 6 1 The current is adjus ted by varying the pulse width duty cycle of the control signals applied to the power MOSFET gates thus allo wing the coil and magnet fields to reach alignment more or less quickly And it follows at low current we get low rotation speed and conversely The entire control principle of this type of motor depends on the response to only one question when should the commutation from step n to step n 1 occur For that we must be able to detect magnets passing in front of the coils and to remain in perfect synchro nisation with this mechanism at each step In addition we must verify that the motors are really synchronous motors because in the end stator flux and mechanical rotation speed will be identical with only one pole pair the number of pole pairs determine the ratio between electrical time time required for six switches and mecha nical time time required to complete one complete physical rotation The refore one motor with only one pole pair will need six commutations step 1 tthrough 6 to perform one 360 de
199. tomatic Gain Con 050359 11 trol for Elektor DRM Receiver This sub circuit was originally devel oped for the DRT receiver Here 050359 12 050381 11 it is usually easier to connect a parallel resistor The added resistor Rp does not have to be a close tolerance type as it has less influence on the equivalent value In most cases a 5 tolerance type will be more than adequate 050381 1 its output voltage 0 4 V controls the LED brightness The dashed lines denote the connections between the existing Elektor DRM receiver and the add on circuit for automatic gain control Depending on the degree of illumi nation by the LED the LDR resist ance will vary between about 1 kQ and 1 MQ The feedback network in the receiver fixes the gain at about 9 times At an LDR resistance of 1 kQ the gain rises to about 220 times This system provides a gain range of 27 dB That s just about right for this receiver raising the sensitivity without the risk of overloading by stronger signals The AGC improves the perform ance of the Elektor DRM Receiver in respect of weaker signals Adding it is worthwhile in almost all cases but even more so if the receiver is used to listen to ana logue AM broadcasts For that application we found Peter Carnegie s G88JCFSDR pro gram www g8jct dyndns org very useful This software defined radio excels in filters with adjustable bandwidth
200. torque of 130 Newton metres Together the two motors form a permanently engaged three phase electronically controlled drive operating from a maximum voltage of 650 V The battery for the hybrid system is made up from a total of 240 NiMH cells With a nominal cell voltage of 1 2 V this makes for a total battery voltage What keeps it turning Fundamentally all electric motors consist of two magnetic sys tems which interact with one another One is fixed and is called the stator The other is mounted so that it can rotate and is called the rotor In modern DC electric motors one of the systems is invariably constructed using permanent mag nets with fixed polarity while the other is constructed from electromagnets whose polarity depends on the direction of current flow in them The interaction between the two systems is governed by the familiar principle that like poles repel and unlike poles attract To achieve continuous rotation it is nec essary to reverse the polarity of the electromagnet system at the moment when the two previously unlike poles come to their point of closest approach In electric motors this polarity reversal is called commutation In conventional motors the polarity reversal is achieved using purely mechanical means where copper commutator segments rotate under fixed brushes with which they make electrical contact In brushless BL motors electronic circuits in the form of bridges constructed from power FETs
201. tp www livinginthepast demon co uk een equency setting 100 kHz step for 25 Here you will find our mains and output P 50 MHz transformers in Mike Holme s range of valve tube IE P kHz step for more amplifiers PP amp SE Also circuits parts lists an 50 Mhz chassis advice 80 EAGLEPICS http www eaglepics co uk Embedded Internet Solutions e Stand alone TCP IP module e Platform independent e Simple AT like command seti e GPRS or modem connection e E Mail FTP HTTP UDP e Development board available e Free development utilities e Free UDP only stack EASYSYNC http www easysync co uk Easysync Ltd sells a wide range of single and multi port USB to RS232 RS422 ELNEC www elnec com a e device programmer manufacturer e selling through contracted distributors all over the world e universal and dedicated device programmers e excellent support and after sale support e free SW updates o reliable HW e once a months new SW release e three years warranty for most programmers FUTURE TECHNOLOGY DEVICES http www ftdichip com FTDI designs and sells USB UART and USB FIFO interface i c s Complete with PC drivers these devices simplify the task of designing or upgrading peripherals to USB FUTURLEC http www futurlec com Sav
202. tronics magazine The articles on the CD ROM cover test amp measurement equipment amplifiers digital audio and loudspeaker technology Highlights include the Crescendo Millennium Edition Audio DAC 2000 Audio ADC 2000 and the IR S PDIF Transmitter and Receiver Using the included Acrobat Reader you are able to browse the articles on your computer as well as print texts circuit diagrams and PCB layouts 12 05 US 21 25 Microcontroller Basics ISBN 0 905705 65 3 2 3 308 Circuits Modern High end BESTSELLING BOOKS ISBN 0 905705 67 X 18 70 US 33 70 25 95 US 22 90 ISBN 0 905705 65 3 265 pages 25 95 US 22 90 PC INTERFACES UNDER NEWS pee sme ISBN 0 905705 65 3 265 pages 25 95 US 22 90 MICROCONTROLLER Basics Valve Amplifiers Handbook for sound technicians More information on www elektor electronics co uk nline at ectronics co uk Due to practical constraints final illustrations and specifications may differ from published designs Prices subject to change See www elektor electronics co uk for up to date information ESR C Meter September 2005 Kit of parts including PCB default LCD module 2x16 characters and programmed controllers Enclosure not included 040259 71 63 99 119 95 Matching enclosure E 040259 72 i 6 99 12 95 Electrosmog Tester June 2005 Ready built PCB excl enclosure 050008 91
203. ts Fieve ete eae Kelis Hee tray ie sheer Hos caps rar Diss Capa The Ayus 536 temperature controded Soldering iron i one of our beat aq dens Hi a W 204800 iron with an Shand amp spare clement 24 gg Ami mich mee Before phoning us if you are looking for a hard to find part We have over 20 000 items in stock including obsolete and up to date parts WHY NOT VISIT OUR WEBSITE www cricklewoodelectronics com 2N 2SA 2SB 2SC 2SD 2P 2SJ 2SK 3N 3SK 4N 6N 17 40 AD ADC AN AM AY BA BC BD BDT BDV BDW BDX BF BFR BFS BFT BFX BFY BLY BLX BS BR BRX BRY BS BSS BSV BSW BSX BT BTABTB BRW BU BUK BUT BUV BUW BUX BUY BUZ CA CD CX CXA DAC DG DM DS DTA DTC GL GM HA HCF HD HEF ICL ICM IRF J KA KIA L LA LB LC LD LF LM M M5M MA MAB MAX MB MC MDAJ MJE MJF MM MN MPS MPSA MPSH MPSU MRF NJM NE OM OP PA PAL PIC PN RC S SAA SAB SAD SAJ SAS SDA SG SI SL SN SO STA STK STR STRD STRM STRS SV1 TTA TAA TAG TBA TC TCA TDA TDB TEA TIC TIP TIPL TEA TL TLC TMP TMS TPU U UA UAA UC UDN ULN UM UPA UPC UPD VN X XR Z ZN ZTX many others We accept Mail telephone amp email orders Callers welcome Opening hours Mon Sat 9 30 6 00 Connect Cricklewood Electronics Ltd 40 42 Cricklewood Broadway London NW2 3ET Tel 020 8452 0161 Fax 020 8208 1441 sales cricklewoodelectronics com WIZ C for the PIC Rapid Application Development in C NOW available with USB Development System m E E E a 1 a ee ea EW zi j 1 SRR PRGA WI
204. ture machines CONUN 38 A 16 bit Tom Thumb Thanks to the efforts of Elektor Electronics and Glyn for the first time now a European elec tronics magazine supplies a complete microcon troller starter board and accompanying software CD ROM at less than 10 pounds We already introduced the Rene sas R8C in the previous issue Now it s time to start using it 46 Inexpensive Web Server Here s how to modify an 20 router into a network or web server We do need to add some extra storage space and also show you how to add a USB port fo an inexpensive router Apart from providing the required mem ory expansion it also offers ways to implement many other applications 16 34 22 38 46 60 70 74 50 56 Volume 32 February 2006 no 351 The Quiet Revolution Micro Motors Brushless Motor Controller A 16 bit Tom Thumb Inexpensive Web Server Sparks n Arcs 6 V Dynamo Regulator Design Tips Automatic gain control for DRM receiver FBI Siren with flashing light Parallel resistor calculations Gain control for Elektor DRM receiver Digital sinewave reference generator technology Audio Amplifier with Problems E blocks now you CAN Colophon Mailbox Corrections amp Updates News amp New Products Sneak Preview infotainment Quizz Away December 2005 solution LabTalk Our Components Retronics The Old Physics Lesson Hexadoku 2 a lektor lectronics Volume 32 Number
205. uit That made it easy to vary the output volt age If you use a normal transformer we recommend using a switch on delay circuit such as the mains on delay circuit published on page 74 of the July August 1997 issue of Elektor Electronics You can also power the cir cuit from a normal regulated power supply Of course the supply must be able to provide 80 V and a couple of amperes and current limiting is proba bly desirable to increase the useful life of various things If you use such a supply the value of R10 should be increased to 1 kQ or somewhat more as otherwise the dissipation of R10 will be too high as will the current through D4 050192 1 Figure 8 This shows how you should wind the transformer Although this is version 2 0 of the transformer as opposed to version 3 0 in the photo of the prototype the winding method is the same Legend C4 in the schematic C1 B2 A2 C2 and C3 B1 Al elektor electronics 2 2006 Our components Component choice for Elektor projects Karel Walraven Newcomers to this magazine quite often send us emails with lots of questions about the compo nent choice for projects described in the maga zine Although photographs of our prototypes provide lots of clues they can t tell the whole story of how we picked such and such a compo nent for a specific function Some additional information is given in this article In the pa
206. ur Readers Services and with several follow up articles including a C Programming mini course in the pipeline our R8C project is expected to generate quite a bit of interest As you read this my colleagues Denis and Patrick in the website department will have created easy links on the home page to a special R8C section that takes you to the ordering system or to dedi cated topics in our online Forum There we hope users will start exchanging ideas and help each other in case of problems With apologies to those already aware of it our online Forum is open to anyone write access to Forum topics however is a privilege of those of you having subscribed free of charge to the E weekly newsletter My current estimate is that about 35 percent of buyers or subscribers to the maga zine have already done so which is encouraging to say the least Jan Buiting Editor ektor Secitronics Brushless lt S Motor Controller This article should appeal to enthusiasts using radio controlled scale mod els that include an electrical motor without permanent magnet brushes usually called brushless motors These ultra quiet motors require complex drive electronics and Elektor comes up with the goods Piezoelectric actuators and motors are finding more and more applications These drives feature excellent dynamics accuracy down to nanometres and tiny physical dimensions Nothing to stop the march of the minia
207. urther his hobby sufficient timing level by manually setting the current and the time bet ween each commutation to be able to detect the electromotive force on the unenergised windings from which comes the characteristic clicking noise at start up with sensorless control lers In this application this phase is always at 12 kHz of PWM in sampling mode during OFF time ST patented method see Figure 8 Once started the micro will automatically switch into synchronous rectification mode at the PWM frequency that has been pro grammed by the user and sampling during the ON time see Figure 7 Attempt at conclusion It is absolutely impossible to make a detailed presentation of control methods related to brushless motors in only a few pages and there remain many things to say regarding theory as well as about the ST7MC microcon troller However the more inquisitive among you will be able to satisfy their desire for further knowledge by rea ding the many application notes on the STMicroelectronics website AN1905 for example http www st com ston line books pdf docs 10267 pdf The software was written in C and requi red several months to develop The choice was based on the COSMIC compiler 16 k version free on the COS MIC website http www cosmicsoftware com down load_st7 16k php which is a reference in terms of code optimisation A down loadable generic library on our Elektor website gives you the opt
208. vi ating curve This led is to the conclusion that the driver IC a HIP4082 from Intersil had to be responsible for the problems in the output stage ThA Time TROT CT BS 16 um i PO CH HI ery ote il col Hl Fii Gi 151 976 Hr Figure 5 After a few modifications the output signal from our test circuit finally started to resemble the input signal 53 TECHNOLOGY AMPLIFIERS Test circuit We were now in so deep that the phenome non would not let go of us any more We decided to order a few of the driver ICs from Intersil and built our own test circuit We simply had to know what was going on For our own version of the output stage we bought the DIP version of the IC HIP4082IP instead of the SMD ver sion For the MOSFETs we used TO220 types IRF530 from ST We used stan dard parts for the remainder of the cir cuit as well Of course as a result the active part of the circuit turned out a little larger than the original amplifier but our test circuit should nevertheless give comparable test results We delib erately did not put the output filter on the PCB so that it was easier to exper iment with the core of the circuit On the single sided test PCB the dead time was made adjustable by connect ing a potentiometer in series with the resistor at the DIL pin so that we could measure the effect of this For the signal generator we designed a purely digital circuit specifically for this t
209. w At the end you ll see the longed for message that signals success Build Finished 0 Errors 1 Warning No errors that s very good Warnings occur relatively often and aren t all that dramatic In this case the warning reads Warning In30 License has expired code limited to 64K 10000H byte s You don t have to worry about that because you re using the free ver sion of the compiler and 64 kB is any how more than R8C 13 can hold If you wish you can download the output file to the microcontroller again and run the program It will work just as well as the Motorola hex file on the CD Now let s have a look at the source code while 1 pl 0 pl il pl 2 pl_3 for t 0 t lt 50000 t pl 0 pl il pl 2 pl 3 for t 0 t lt 50000 ttt Loop e 1 e v e 1 O oOo o oO e v e v 1 1 1 1 0 e 1 The core of the program consists of a simple self explanatory loop First the ports are enabled then there is a wait loop then the bits are disabled and Connection Typa he FLASH Deveiornert oski can conmmect a UU AEA d mamisa of ferent a A Ges apra on at fuse riy bee iair a P BOOT Mogren mode the dernoa marea it LASH pau to Sonmchom Tha iia eri re aa hireak Bo thee are af equ The Fcon Speed eeftng ct lice an tie curent dean rd clock The weer may abo nout thes on fin a supported fea the tered field the gar FIP Parvummonaded Spends nui
210. ware tools Cambridge Consultants Ltd Science Park Milton Road Cambridge CB4 ODW UK Tel 44 0 1223 420024 Fax 44 0 1223 423373 www cambridgeconsultants com 06701 6 6 pooling for standard boards Verified up to 6 layers from 1 to 1000 pieces from 4 working days onwards technology at the right price la carte up to 8 layers from 1 to 1000 pieces from 3 working days onwards your board our challenge up to 20 layers On demand from 1 piece onwards from 2 working days onwards elektor electronics 2 2006 SOT 23 Li ion Li polymer battery charger Microchip announces the expan sion of its power management family with the MCP73831 bat tery charger a fully integrated single cell Li lon Li Polymer charge management controller Equipped with a pass transistor current sensing and reverse dis charge protection the MCP73831 charger reduces the number of components needed for battery charger designs Another key feature of the MCP73831 charger is its simple status output that directly drives single or multi colour light emit ting diodes LEDs Its highly accurate pre set volt age regulation maximum up to 0 75 percent results in more fully charged batteries and extended battery life In addi tion the device s charge current is user programmable enabling customized charging currents for specific applications The con troller also features
211. wering four standard servos with 20 volts given the power to be dissipated in this case we need to opt for a switch mode power supply or simply a separate external battery for the receiver and servos It all depends therefore on the work load type of servos and the power to be dissipated it only concerns one K1 050157 11 25 RC MODELLING demagnetisation adjustable phase advancing bg p a g le us pa Sia phase 2 T1 T6 sampling l E 4 TA H HI afa fill Y pe DI AN el ae rt HOON H I zero crossing commutation 2 E Ell I internal p reference t m F 0 2V I 050157 17 Figure 6 Sampling during OFF time linear regulation Regulators are used to power one receiver and several ser vos with no problem with approxima tely ten volts be careful that there is no resistance in the controls because consumption can rapidly bring about overheating of the regulators followed by a standby setting The signal coming from the receiver is applied to pin PD3 and the D1 R3 network is used to somewhat boost the receivers ope rating at low voltage 3 3 V A small I2C EEPROM is used to backup controller programming PA3 is connected via a resistor divider and is demagnetisation used to monitor battery voltage The MCES input pin 4 is used to put the power stage on standby when a low level is applied to it it is not used in the setup
212. wigo ges Obalo ope tim ob coe Sac tw ta SOediwv Zea ty te 5De ty Jaadw to SOe dw Compact amp portable MONUTA stem Open 30pm n n Seactrer ros Otte ALLAN o DOMhHe D te tOOMiMe Supplied with PicoScope amp PicoLog software eee tem pce en Hesostetice eccerecy S tits 2 llm gen 100W te 190V PC Com eection USHI D LS 1 1 comepetrblal PICO Ci hnolog y Limited Tel 44 0 1480 396395 www picotech com scope287 2 2006 elektor electronics 33 KNOW HOW MOTORS 34 Micro Motors March of the miniature machines Jens Nickel Figure 1 This piezoelectric motor with a single channel drive can produce linear and rotational movements 3 Source Elliptec Bild Elliptec Piezoelectric actuators and motors are finding more and more applications These drives feature excellent dynamics accuracy down to nanometres and tiny physical dimensions In many cases the discovery of a new physical phenom enon has precipitated an immediate technical revolution examples include X rays and the transistor In other cases it has taken several decades before the potential of a discovery is realised such as in the case of super conductivity discovered in 1911 and the effect we describe below In the year 1880 two French brothers Jacques and Pierre Curie discovered that charge is generated on crystals of tourmaline when pressure is applied This became known as the piezoelectric effect from the Greek word pieze
213. y ooC3 PSoC Starter Pack 119 00 High quality development board Built in USB 2 0 programmer Windows 98 ME Z000 XP compatible Supports ihe kalesi 80 pin microten trailers trom the 18F PlOmicro tamily On board LEDs switches potenti ometers two AS 232 interaces PS 2 connector and MMAC SD and Com padi Flash card slots All VO lines avadable for expansion BRGPICS Starter Pack includes PIC18F 8520 MCU module 16a2 charader LCD lt 128x64 pixel graphic LCD DS16520 temperalure sensor USB programming power lead High quality development board Built in USS 2 0 programmer Windows 96 ME 2000 P compatible Supports 64 and 80 pin digital signal comroliers fram the dsP C30 lamily On board LEDs switches two AS 232 interlaces AS 485 interlace two CAN interfaces real time clock 12 bet A D and OA and CF card sini All DO ines available lor expansion GPICPRO Starter Pack incluces dP ICSOF 6014 DSC module 16x character LCD 128064 pical graphic LOD DS18S20 temperature sensor USS pregramming power lead lt Programming software and examples High quality development board Built in USS 2 0 programnver Windows 8 ME 2O000 P compatible Supports amp 4 pin AVA microconinodiers On board LEDS switches poberi omens wo AS 232 interlaces PS 2 connecor and MMC SD and Com pact Flash card shots l VO Enes availab
214. y be read from a graph When increasing the dead time the output voltage appeared to collapse and reach some sort of limit It was much better when the bootstrap Capacitor was increased and after increasing the supply voltage to 15 V the output signal finally took the shape that was expected Figure 5 Measurements were made without a load through a simple first order RC filter so that the remains of the pulse width modu lation are still clearly visible on the oscilloscope Why the remainder of the posi tive output voltage when the power supply voltage is increased passes unhindered through the FETs is still a mystery Increasing the power supply voltage to the bridge made no difference to the operation Our test circuit did exhibit a similar behaviour as we had observed with the CDAMP sample when the power supply voltage was lowered During our experiments half of the bridge in the IC burned out sponta neously on two occasions The first time it was not entirely clear what caused the malfunction The second time it happened when increasing the dead time when a 4 2 load was con nected This signalled that it was time to stop with this experiment Conclusion Considering the results from our test circuit it is not likely that we will use the HIP4082 in a new design The only thing the IC needs to do is to turn the MOSFETs on and off making sure that both FETs in one half of the bridge do not c

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