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RE: Sold state IGBT disruptive coil spark gap idea

Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>


Late report...

It was trivial to add the diode tonight so I did...

It fixed everything!!!!! :-))))))))))))))))))

The gate drive voltage now locks right in at about 27V just like it is supposed too (these are all like 25kB "little" files now ;-)):


After the first peak, the IGBT is locked in good and hard ;-))

It "stays" on just like it is suppose to too :-)) That timing is trivial to change...


I pulled out the jumper so the module is running at the full 900V here:


No problem at all running 150 amps :-)))

This is the current through and voltage across the gap:


Power dissipation is high:


"But" there is "no where else" for the power to go except the gap in this case. The ringdown seem equal to a direct wire short. It "needs" a secondary ;-))) :


Efficiency seems to be roughly 60% so the rest of the power is in the coil, cap, and wiring...

Here is the board front:


And back:


I suspect is should be a perfectly stackable 900V 500A module. Might need resistors still across the SIDACs for stability but that is a tiny thing (I think Peter mentioned this).... It should not be "blow up able", but NO direct streamer hits (maybe the gate circuit could "take it" though...) ;-)) Looks like around $12/900V of gap... Might be real good for lower voltage MOT coils ;-)) Almost "any" IGBT with diode could be used.

Sync gaps are a little problem, but the string could be fired "early" by shorting a small portion of the gap with conventional electronics. A say 2000V section could be "triggered" and the other modules would follow... Perhaps the gate drive voltage circuit could run timers or even PICs... This is all "public domain" so I add those comments just the "break the patents" ;-))

The days of conventional coil "spark gaps" making "bright light" and "load noise" are now probably numbered :-)))

Party hardy!!!!!!!!!!