Re: SSTC- feedback vs. none

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "K. C. Herrick" <kchdlh@xxxxxxx>

Once more for the record, for anyone who's paid any attention to my 
drawing hot-streamer.com/temp/Half-br_res-load.jpg:

I've found in the hardware that there's not enough drive to Q5 & Q2 
to turn them reliably on during spark events.  So I'm having to re-do 
the driver portions to put the Q5/D16 and Q2/D15 elements ahead of 
Q1/Q3 and Q8/Q7--as I should have done in the first place.  That way, 
Q5 and Q2 need only carry the base currents of Q1 and Q8 rather than 
their emitter currents.  (Doing this, I find, in simulation, that I 
don't need resistors R16, R17 or R18.  And adjusting the values of 
what were R3 & R11 by a few ohms tweaks the loop delay nicely for 
zero IGBT common-mode current...as before.)

KCH