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  1. WHONOES

    Video signal amplifier.

    You will need to impedance match your cable at both ends otherwise you will get lots of reflections that will make a mess of your signal. To do that, you will need to know the characteristic impedance of your cable be it, 50Ω ,75Ω, 300Ω or something else entirely.
  2. WHONOES

    12V power supply

    As suggested earlier, I would us a TO220 device and mount it on a small heatsink. A couple of square inches might be enough.
  3. WHONOES

    Pspice Buck Converter Simulation

    Which spice platform are you using?
  4. WHONOES

    Pspice Buck Converter Simulation

    The negative part of your gate drive needs to be connected to the circuit ground. Then you need to add a 90V offset to it.
  5. WHONOES

    Pspice Buck Converter Simulation

    Correct about thyristors. All of them have what is termed a "latch current". This a current level that when exceeded, causes the thyristor to latch or stay on irrespective of what is happening to the gate. The only things that will then turn the thyristor off are if the anode goes negative with...
  6. WHONOES

    PWM for Servo w/o Microcontroller

    I built one years ago using a 556 which is just two 555's in one package. It used a frame rate of 50Hz and was fully proportional with a pot to control rotation.
  7. WHONOES

    Control alternator voltage back to 6vlt battery?

    I had in mind something slightly simpler. See attachment. Adjust VR1 to maximum value. Connect circuit across battery terminals whilst your bike is not running. Make sure that no current is flowing in the circuit at this point. Start Bike then adjust VR1 untill you get the charge voltage...
  8. WHONOES

    Control alternator voltage back to 6vlt battery?

    You could try a simple shunt regulator consisting of a beefy Darlington transistor, a power resistor a pot and two more resistors.
  9. WHONOES

    PCB layout software?

    R.S. Components offers free Schematic capture and PCB design software that seems to be similar to Easy PC. There are how to use guides on youtube.
  10. WHONOES

    Toroid core types by color ID?

    Some do. I still have some colour coded cores. Unfortunately I can't remember who the manufacturer is / was. If I do, I will come back.
  11. WHONOES

    Attract fish by sound, light or anything else

    Try bait!
  12. WHONOES

    How is a brass gear removed from a DC motor?

    File one side of the gear off parallel to the shaft. It should comer off quite easily then.
  13. WHONOES

    DC Circuit Breaker Connected Position Selection

    Consider what might happen in each situation.
  14. WHONOES

    320 V DC 15 amps current limiter circuit

    So you need to turn of the drive to the IGBT's.
  15. WHONOES

    320 V DC 15 amps current limiter circuit

    It is easy enough to monitor the current in your system, it just depends on how you are going to integrate it. You would presumably want to limit the PWM pulse width to a minimum to achieve this or, do you want to bypass the digital control altogether?
  16. WHONOES

    320 V DC 15 amps current limiter circuit

    So, can you inhibit the fet via you micro or gate driver. Does the gate driver have an inhibit pin?
  17. WHONOES

    320 V DC 15 amps current limiter circuit

    How are the IGBT's switched?
  18. WHONOES

    'Frosting' on top of Ni-Cd batteries

    Looks like the cells have valves on them to vent gases to atmosphere when they are overcharged or abused in some way. The frost is precipitated from the gas released and represents a loss of electrolyte which means reduced capacity.
  19. WHONOES

    Help select suitable Mosfet for driving relay.

    Absolutely right heavans1944. They need to be hard on in saturation of fully off otherwise they will be subject to high dissipation.
  20. WHONOES

    Help select suitable Mosfet for driving relay.

    Agreed on the mosfet front.
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