Very impressive - what drive system are you using and what
do you use for tank capacitors?

Jim

Jim,

I'm using a TL494 for the frequency and duty cycle generator. The
output of the frequency generator feeds a pair of Mosfet gate drive
chips, thru a 1:1 transformer to the gates on the 4 corners of the
h-bridge.

My first experiments didn't use tank capacitors, but I found I HAD to
have them to heat the graphite efficiently. Currently I'm using 12x
0.1mf caps in parallel as the tack capacitor, but this is a problem.
The capacitors can't handle the REALLY HIGH ripple current (100 amps
or more?) and I keep melting the legs off.

I'm currently on the hunt for a nice water cooled 2mf cap, but not
having much luck. Most of the ones I'm finding or for high voltage,
not high ripple current.


Take Care,
James Lerch
http://lerch.no-ip.com/atm (My telescope construction, Testing, and Coating site)

Press on: nothing in the world can take the place of perseverance.
Talent will not; nothing is more common than unsuccessful men with talent.
Genius will not; unrewarded genius is almost a proverb.
Education will not; the world is full of educated derelicts.
Persistence and determination alone are omnipotent.
Calvin Coolidge