High Voltage DC Power Indicator

[rdvernon]

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.

 

[berkeman]

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