Driving circuit FET problem

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "george hadle by way of Terry Fritz <twftesla-at-qwest-dot-net>" <ckreol1-at-yahoo-dot-com>

hi, My driver circuit its an ignition coil driven by a
FET protected by schottky diodes.
The problem has several symptoms, all independent of
the TC being connected or not.
If I short the hv terminal to ground, the circuit
completely ceases output.  It can spark between these
two terminals without problem, its only when directly
shorted it messes up. Whether the output is latched ON
or cut OFF, I think its latched ON.
I'm running it at audio freq. and the sound of the
coil completely stops.

I can rectify the problem for a few seconds one of two
ways.  Turning off and back on.  Or changing the
frequency of the FET driver, which is a schmitt
trigger oscillator.
any ideas?
thank you very much
george

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