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Re: SISG first sparks!

Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Great job Terry,

Whats determining the 60BPS?? I would presume that you are full wave rectified. Can your tranny recharge the DC cap in a 1/4 cycle??? If so, I would think you would be at 120BPS.

When you have a bunch of SISGs in series, and the voltage reaches a level where say one SISG fires, this results in a cascade firing of the other SIGSs. Question is, once the SIDACs fire on a subsequent SISG, how long does it take for the IGBT to turn on??? Im wondering if the source to drain voltage can get beyond spec due to the cascading effect before the IGBT turns on.

Gerry R.

Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>


I wired up some odds and ends and put the gap on a coil:


The firing voltage is 1800V and it is running about 60BPS. The arc to ground is 5 inches.

The coil is 150kHz and the primary cap is 150nF so the bang energy is 0.243 Joule. So its about 14.6 watts. The old IGBT got just barely warm and the new one stayed cool (no heatsinks).

This system was very far from optimal, but it did make nice sparks with the new gap ;-)) When I get a lot more IGBTs, I can run it at 100 times the power ;-)))