Q - Driving HV DC pulses? (fwd)

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Original poster: <sroys@xxxxxxxxxxxxxxxxx>



---------- Forwarded message ----------
Date: Mon, 03 Oct 2005 21:52:29 -0400
From: Jeff Bullock <jeff@xxxxxxxxxxxxx>
To: hvlist@xxxxxxxxxx
Subject: Q - Driving HV DC pulses?

Hi,

I'm a newcomer to this list.

I have been researching various HV applications. My particular interest is
in building a pulsed DC high voltage generator. It could be useful for many
types of experiments.

My specific needs require that the power is generated from a 12 volt battery
source and that the voltage pulses are of a moderate HV between 1kv and
10kv.

For experimentation it's important to be able to accurately control the
duration of the pulse and interval between. The pulse wave needs to be a
clean, square, DC wave with no polarity oscillations.

There are a number of ways to build the high voltage. I know how to create a
555 timer circuit to produce inductive kick for the HV. But I'm concerned
that the resulting HV pulses coming directly from coils may not be clean
enough.

That's why it would be ideal to come up with an adjustable 555 timer circuit
that acts as a driver to trigger the release of a pulse from an MMC
capacitor bank that has been charged by the initial HV generator. I'm
concerned, however, that normal triggers in low voltage timer circuits like
transistors and MOSFETs, are too delicate to take high voltage.

Does anyone have information on how to time and trigger clean high voltage
square waves?

Someone suggested using a triode. I only know these as tubes from amplifier
circuits. I've never heard of them being used as switches nor anything about
their tolerance for high voltages.

Thanks!

Jeff