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High Voltage DC Power Indicator

  1. Jul 27, 2008 #1
    I have a 20kVDC pulse flowing to an igniter. 2500 pulses per minute. I want to know if it is possible to use the high voltage pulses of DC to induce sufficient voltage in a coil wrapped around the power cable (through which the current is flowing) to energize an LED (in synch with the pulses). Any advice on this would be sincerely appreciated.
  2. jcsd
  3. Jul 28, 2008 #2


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    Staff: Mentor

    You don't wrap the coil around the power cable. To use the current in the cable, you need to form a "current sense transformer" where one lead of the cable goes through a ferrite toroidal core, and then you wind some number of turns on the toroid as a secondary coil. The one pass through the toroid by the power lead is a single turn coil, and your secondary has some number of turns that you tune to give you enough voltage to light your LED. This taps a little bit of power off of the power lead, but not much as long as you limit the current through your LED.

    See "Instrument Transformers" or Current Transformers here: http://en.wikipedia.org/wiki/Transformer
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