Is it worth using staccato with OLTC?

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

Original poster: "Stephen Conner by way of Terry Fritz <teslalist-at-qwest-dot-net>" <steve-at-scopeboy-dot-com>

Hi guys,

With all this talk of staccato controllers I'm trying to figure out whether 
my OLTC would benefit from one. I'm interested in running at very high 
break rates, but I already blew one IGBT (cause of death unknown) so I want 
to leave a little safety margin. I already got the first notch quenching to 
work, which made the IGBTs run cooler, and also boosted the performance so 
that it breaks out without a breakout point. Unfortunately the high voltage 
field is now making the control board act funny (maybe it was a misfire 
that killed my IGBT?) so I have to stop messing about and make a proper 
shielded control box.

Under these conditions (if I read the IR data sheet right) the IGBTs will 
be good up to about 400bps continuously. OTOH, using staccato mode it could 
manage short bursts of 1600bps operation at a duty cycle of maybe 5-10%. 
So, I'm wondering if it's worth the extra hassle. After all, 1600bps 
staccato'ed to 10% is less average power than 400bps with no staccato. But 
then again the power level during the burst is 4x as high. I guess it 
depends on which heats up faster, the air I'm trying to ionise, or the 
transistors I'm trying not to melt.

Does anyone have any thoughts on this matter, or any relevant data? I need 
to make my mind up before I start drilling holes in the control box :D

Steve C.