LTR vs. STR for pigs was Re: PFC Question

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Steve Conner <steve@xxxxxxxxxxxx>

Hi all,

This debate got me thinking and I thought of a few
things I'd like to bring up.

1) What decides whether a cap is LTR or STR? The
answer is the leakage inductance of the transformer.
Now in a NST that is built in, but a pig has
practically none so you need to provide your own
external ballast. So, it is not the pig itself that
determines whether the cap is LTR or STR, but the
ballast. (And the transformer turns ratio too, I
suppose.)

2) Someone said that bang energies of 50J were out of
the league of garage coilers. That was before the
DRSSTC, which can generate bang energies several times
bigger than the energy storage capacity of its tank
cap. I believe Steve Ward's big DRSSTC must run about
50J bangs.

I have got over 3kW at 200bps into mine which implies
a bang size somewhat under 15J (allowing for about
15-20% losses.) I was using a 0.1uF @ 10kV tank cap,
and since I was running about 400A peak at ~190kHz,
the tank cap voltage would have been only 3.3kV and
hence the stored energy would be less than 1J.

I don't know how it does that, but it does. It seems
the primary and secondary coils are now just a
matching network that couples the inverter to the
plasma load. The lower the Q of the matching network,
the more efficient it is, and the less sensitive to
streamer loading. I was reading an article on link
coupled antenna tuners for ham radio and there seem to
be a lot of similarities.

Steve Conner
http://www.scopeboy.com/