Re: Driving circuit FET problem

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

Original poster: "Ben McMillen by way of Terry Fritz <twftesla-at-qwest-dot-net>" <spoonman534-at-yahoo-dot-com>

Hi George,
    When dealing with transformers of any kind, it is
important to remember one simple equation: power in = power
out. It takes a certian amount of voltage and current to
drive the primary side of a tranny. The voltages and
currents on the secondary are inversly proportional to that
of the primary (depending on whether it's a setp up or step
down) and power in must equal power out. When you short the
secondary, the voltage drops to zero and the currnet goes
way up. The primary is probably trying to compensate and is
pulling too much current from the drive circuitry, shutting
it down...

Just a thought.. Anyone else have any thoughts? I'm not too
up to date with SSTC driver circuitry..

Coiling In Pittsburgh
Ben McMillen

--- Tesla list <tesla-at-pupman-dot-com> wrote:
 > 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
 >
 > _
 >