JohnF,
I got that book you recommended, fairly cheap used, and it's one of the better ones on the shelf, I agree.
(now I can't find where you mentioned it, so I'll mention it again here)
Switching Power Supply Design
Abraham L. Pressman
McGraw-Hill
ISBN 0-07-052236-7
Found it for about 50 bucks ($273 new). I already knew most of the content, but it's still a big winner. One of those that are more expensive to not-own than to own.
I see where people are using fancy LC's in things to try and get around the inevitable low self resonance of a high turns ratio transformer, and then deal with the fast edges without burning switches up (like Carl just did on fusor.net), but I also find that usually there's enough leakage L in things that I can tune that very simple H bridge driver for least quiescent current and it's fine if the frequency is high enough for the use intended. I tend to cheat a little and just brute force the core itself, more volts/turn, and keep the resonance high that way. After all, I'm not CliffS who has to make money at this game, just a guy who needs onesies. This looks like a winner as is. That weird transformer pictured above has a ton of interesting peaks in the impedance spectra, so it doesn't seem to mind the rather cavalier treatment.
If not, I may "graduate" to adding some L across the xfrmr primary for starters. The FETs I'm using (irfp264 in this one) don't mind having the diodes "hit" before the other FET turns
on, it seems (that driver has a lot of dead time), and a minimal RC snubber keeps the heat down in the semis and actually is what eats most of the power at no load. As the load goes up, things actually cool off....so far.
I've now tested this with one stack disk up to 20kv, and it is eating about 60w waste power, a bunch in the snubber, the rest in the fets and xfrmr. Not so bad. I've found
this usually gets better with some load on things -- eats the energy stored in the xfrmr so there's less kicking back.
I'd love to figure out a way to use one of those power factor correctors to pre-regulate the rails to the H bridge to control power, but as they are boost-only, and I need
down to nil and up to about 150v, I guess I'll have to make a buck mode switcher for that. No big deal if I can put my hands on the right core material for the L for that.