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  1. poor mystic

    AC and DC Voltages for Electrolysis

    A full-wave rectifier, usually consisting of 4 diodes, will remove rust faster, I presume, since it provides current over the full cycle of the AC potential instead of only a half-cycle.
  2. poor mystic

    AC plug wires are reversed and Above ground potential

    I think it might be time to ask an electrician for help.
  3. poor mystic

    Driving a led from high-voltage source

    :) I consider the result you want to be impossible. Sorry, but at least you'll survive.
  4. poor mystic

    Driving a led from high-voltage source

    :) Hooray! I don't know what this voltage source of yours can be but it's lethal. There's no way to safely regulate 5kV, and there is certainly no IC which is capable of channeling currents at such voltages. What's it for, please?
  5. poor mystic

    Driving a led from high-voltage source

    :) Hi I hope you don't do this thing. It freaks me out, and I'm brave and tough. 5kV is too high a voltage. Please do not feed current from your source to any switch - you or someone else might so easily die as a result. When you've accepted that, I'll listen more, but right now I want to be...
  6. poor mystic

    Suggestions for replacement of an electromagnetic changeover relay

    I've always preferred another approach - I'd rather use the onshore mains to keep the battery charged, and draw all my current from the battery. There's no load on the battery unless shore power fails, in which event a lamp on the shore power side would go out, providing a visual indication.
  7. poor mystic

    Comedy Thread

    plumber
  8. poor mystic

    How do I increase Voltage, USB extension cable is causing voltage drop.

    OK, you need to know how to design a "power supply". There are lots of books and all, but the first thing you'll need to understand is a simple, unregulated supply, which will consist of a transformer, a rectifier, a capacitor, and a load. It's good to see the load as part of the power supply...
  9. poor mystic

    Forward Current, Forward Voltage, Reverse Voltage...

    :) Ohm's Law would make a very useful app, whether for Android or Windows.
  10. poor mystic

    hospital yet again

    yeah Dave the nurses are nice but not that nice get well soon :)
  11. poor mystic

    Variac repair/parts

    Very likely, no-one wants to encourage you to kill yourself in an electrical accident. Get an electrician to make your variac safe. :)
  12. poor mystic

    How do I increase Voltage, USB extension cable is causing voltage drop.

    It sounds a lot easier than it is, to increase voltage. Reducing it's easy enough, like spending money... but increasing voltage usually means starting afresh. Anyway, I hope you noticed what Davenn said just above :)
  13. poor mystic

    Current limiter circuit design

    Hi :) I'm sorry, I haven't been able to work out what you want. If you want to time the motor's ON period, I believe you need a timing circuit. If you want to limit current, you'll need to measure current somehow, and control it using some kind of regulator. However the LM317 is not a good...
  14. poor mystic

    How do I increase Voltage, USB extension cable is causing voltage drop.

    :) Hi Red If a set-up that worked fine in the past no longer charges your phone, you'll need to test to find out what has changed. The candidates are the transformer and the extension cable. If the extension cable charges your phone from another transformer, your existing plug-pack might be...
  15. poor mystic

    Wire temperature control

    All good suggestions I am sure. On the hardware side, I suggest that switching the MOSFET fully on and fully off many times per second, with a variable duty cycle, would be a much better way to control the power dissipated in the heating resistor than having your transistor switched half-on...
  16. poor mystic

    What can cause logic glitches

    power supply problems. (I believe in testing the supply before anything else.)
  17. poor mystic

    Measuring digital coincidence

    In the sense that things coincide... i.e. happen at the same time or synchronously.
  18. poor mystic

    AC plug wires are reversed and Above ground potential

    I don't believe it's possible to test for all potential faults by any method. If the equipment you're working on is as bad as that, use the isolating transformer - it's a lifesaver.
  19. poor mystic

    Measuring digital coincidence

    Hopefully, the circuit architecture does not allow logic races; a circuit which could fail in that way would be badly designed.
  20. poor mystic

    temp control help

    :) Hi Ghost Are you yet lurking in some machine? Welcome to the forum. Thermistors are used to sense temperature, and I believe that high temperature thermistors are available. However they cannot be simply wired across your heating coil and left to short out the supply when things get too...
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