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Everything posted by esp1

  1. hi todd, As you are aware there are lots of A/V channel selectors/scanners available. Depending how far away from the scanner you want the remote push button to be, you can attach extension wires to the switch inside the scanner. Add a low value resistor in series with high side of the button and a 0.1uF cap across the switch in the box. I have extended my switch about 15mtrs and it works OK.
  2. hi, Double left mouse click on a link, [as shown in your thread] You will see a list of three file addresses, click the one you want. Their page will say 'if want to download' scroll down. you will a grey button marked 'FREE', click that. Then you select a radio button, thats the little white button, when you click on the button you want a 'dot' will appear in the white button. If you just glance up the page. it will tell you which file you have selected. Further down the page you will see the DOWNLOAD button, click that enter the 'coded' ID into the white text box... and that should get the job done. You will need some way of unpacking/unzipping the RAR file, you can get free ones on the web, Google!.
  3. hi rotclues, A laser powerful enough to cut thru cardboard is far too dangerous for home project. I would recommend that you download and study the potential hazards from ANY laser device. Why do want to cut thru cardboard with a laser?? ::)
  4. hi, The large blue capacitor is connected to the 'line' [phase] of the incoming mains supply. The design uses the capacitive reactance of the cap to limit the current flowing that low value/hi-watt resistor. You can work out the current flowing in the resistor, by using Xc= 1/ (2 *pi * Freq * Cap) Knowing your local mains supply 110Vac or 240Vac at 50/60HZ depending where you live. The voltage across the resistor is connected to the FWB. I traced thru a simliar device a few months ago, it takes less than 30 mins to produce a working sketch. There are zener diodes and a sometimes a 5Vreg for the sensor chip. Use the sketch to show you the best connection point on the pcb for your 24Vdc. CAUTION: when connected to the mains supply the pcb and components are NOT isolated from the mains. Lets know how you go, post your sketch if you need more help.
  5. The 2 boards that are blowing fuses, have you done a resistance check on the output pins. I sounds as though you have short on the boards, especially as they blow with no battery connected. Do you have a circuit you can post, it will make it easier to suggest a repair. Are the 3.6 Vbty for mobile phones?
  6. Hi, If its blowing the bridge rectifier, the problems not with the fuse link. I would suspect you have a short on the output of the charger. Have you tested across the output terminals with a ohms meter. [ WITH THE MAINS POWER DISCONNECTED] ??? Also, does it blow fuses when no battery is connected to the output?? Also, is the charger rated at the same voltage as the battery, example: 12Vcharger, 12Vbattery?? Also, is the input mains selection for the transformer set for you local mains supply voltage???
  7. hi, I would not normally fit a fusible resistor in a battery charger, a standard, slow blow fuse would be OK. If its a typical battery charger I would expect a 5 or 10Amp fuse would be OK. Does the battery charger have a current meter?? >> relation between the peak primary current? I'm not sure what you are comparing with peak primary current????
  8. hi pier, If you have a spare slot in your PC, you could get anotheer Parallel port pcb fairly cheap, use LPT2. Can you try connecting YOUR printer to a friends PC for a test and vice versa?
  9. hi, Your question is like asking what size fuse shall I use?? Its not possible to suggest a 'fusible link' without knowing more of the application. If possible, post a drawing of the circuit you want to protect.
  10. hi euro, You could consider using say, HEF4013 dual 'D' type flip/flop.[ with a transistor to drive the relay] Positive pulse ON/OFF, they also have a RESET pin. Use a simple R/C on the RESET pin in case of a mains blackout. Your 4011, could restart in any state.
  11. hi euro, You could easily construct a logic circuit using a couple of transistors and a standard relay. The relay would work like a bistable type. With the low current required for the transistor/relay bistable, you could have the transistor bistables in a central control box, driving the remote relays. With all that water around, dont forget the Residual Current Circuit Breaker RCCD, in the mains supply.
  12. hi euro, You can buy logic ic bi-stables, not very expensive, the bistable output would 'latch' the AC module. If you bury electronics, you should use IP68 rated boxes/enclosures, pay special attention to earthing and use a RCCB. Whats the system for?
  13. hi euro, You can buy small encapsulated solid state modules for AC control. There are different types that can switch from 2 Amps thru 10A at mains voltages. They are fully isolated and rated for mains voltages. The control voltage is Vdc from +3V thru +24Vdc, with a very small control current. Hope this helps.
  14. Hi, Have a look at this, ref: bootstrap loader program. http://en.wikipedia.org/wiki/Booting
  15. hi, Most general purpose relays will handle 12Vdc 1amp, just check the relays spec sheet, dont forget to specific the relay coil operating voltage to suit 12Vdc. What components do you have on the shelf? Dont know where you are posting from, so cant suggest a local source!
  16. hi Glenn, You can buy ready made 'LED ropes', that is, LED's installed in clear plastic tubing. They can be hung room corner to centre. The 'user hands on push buttons' could select a 'rope' so that the 4 ropes would be illuminated in various sequencies, is that what you had in mind?
  17. hi, The simple solution would be a transistor controlled by the 3Vout, switching a 12Vdc relay, the relay contacts would then be used to connect the +12v elsewhere as required. Is this clear enough?
  18. hi, This posting has been answered in detail on another forum!.
  19. hi, Just a quick Google for: 'stereo cassette data sheets' gave lots of hits for datasheets
  20. hi, Sawafuji Swing Motor Looked thru your link and associated links for this device. They all indicate that the motor is AC or DC operation??? Do you have a specification sheet for the motor you have?
  21. Hi, As a starting point have a look at this site. http://www.ee.surrey.ac.uk/Workshop/advice/coils/#cor Then you can ask more specific questions regarding transformer design. Regards
  22. hi, Have a look at www.analog.com site and search for 'phantom ground'. Application note: AN581
  23. esp1


    This same question, by the same OP has been asked and answered in detail on another forum.
  24. hi pier, Assuming that the existing 10K pot gives you a linear range of 0 to 30Vout, then the 100R [centred] will give you a +/- 0.15V adjustment, that should be OK.
  25. hi, Most domestic mains supplies are single phase, either around 110Vac or 240Vac. The mains frequencies are around 50 or 60HZ. For example, if a mains transformer was made for the UK, the primary winding would be 240Vac, in the USA 110Vac. Most mains transformers will work OK, with 50 or 60HZ supplies. The important point to remember is how the transformer is used, if it has a low voltage secondary, say 12Vac connected to a fullwave rectifier, with capacitor smoothing. The values of the rectifier and smoothing capacitors would be chosen to suit a known mains frequency. On a lab test you may find that the board will still work, BUT if you tried the same very low frequency on say a domestic appliance, it would most likely damage it! If this dosnt fully explain, please ask.
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