RE: MOSFET/IGBT power supply (ripple)

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

Original poster: "Eddie Burwell by way of Terry Fritz <twftesla-at-qwest-dot-net>" <eburwell-at-columbus.rr-dot-com>

  Well, once we have DC what would be a good method for driving a pig? I
kind of favor the idea of a series resonant converter. Put some inductance
in series with primary of the pig and parallel the cap to the secondary. The
leakage inductance of the pig in series with the inductor and the
capacitance (transformed from the secondary back to the primary) would form
a resonant circuit tuned to the frequency of your choice(50Hz for example).
The primary of the pig with it's series inductor would be driven by a full
bridge of MOSFETs, or IGBTs with anti-parallel diodes. To start things out
one low FET and the opposing high FET would be turned on. Current would
begin to ramp up through the primary eventually resonantly charging the cap
to its peak. As the cap approaches it's peak the gap would the be triggered
(be it a synchronous rotary, triggered gap static or what have you) and the
cap dumped into to the primary to work it's resonant magic. At the point of
peak voltage for the cap or shortly after the FETs would be switched off. If
the gap does not fire for some reason the anti parallel diodes would return
the cap's energy to the supply rails. After some delay the opposite pair
FETs would be switched on and the process repeated.
  This isn't necessarily the simplest method but it does provide some
flexibility. The resonant frequency can be adjusted with the series inductor
and the cap. The pulse rate could be made variable. A triggered spark gap
might be a good match with this setup. 
  How about some single ended approaches? Ideas?

Eddie Burwell