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Re: SCR spark gap results are in!



Original poster: "Virtualgod" <mike.marcum@xxxxxxxxxxxx>

Why not parallel craploads of matched mosfets? Other than the bleak voltage rating of ~1.7kv max (find a way to series/parallel them without cascading failures from different turn-on/off times perhaps) I think you'd have better luck. I think the drsstc with igbt's is even better still since you don't even need a heavy hv transformer. Which leads me to a question: is there a way to determine the best pulse width/freq without having to experiment and blow up a few igbt's (like formulas like there are for dc resonant tc's on richie burnette's website)?

Mike
----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Thursday, December 02, 2004 10:06 AM
Subject: SCR spark gap results are in!


Original poster: eahab el naga <tesla.dude@xxxxxxxxx>

After much debate and experiments, the results of the SCR spark gap
are dissapointing. With the large SCRs that i originally planned to
use, the turn on time was 130us. That was way too slow and the turn
off time being presumably ten times that. Wile the SCR attempts to
turn off several cycles have passed making it impossible to turn...in
turn shorting the powersupply across the primary. Failure....I do not
stop there...i went and bought hyper-SCRs that have a turn on time of
1us and sadly enough the results were the same...with a turn off time
of 10us the scr would only work with coils less than 60khz. I am
greatly dissapointed but i am now working on a single transistor spark
gap replacement. I have a darlington 400A 1000V transistor that is
pretty slow but i only need 120 pulses per second...perhaps easily
accomplishable...Like a good friend always told...its hella hard to
replace them metal switches...

Eahab