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Sold state IGBT disruptive coil spark gap idea

Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>

Hi All,

It's been 24 days now and it is pretty much all finished ;-))

Without messing with coupling, tuning (probably real close), or any thing like that, I can fairly easily hit 24 inches at 117W - and 30 inches at 183W. The Freau number there is 2.22 in both cases. That number seems very "constant".

I was only able to go to 5 sections instead of six due to the limited safety area in my basement. With six sections, it should get to 263 watts for 36 inches. The whole mess could probably be more optimal, but my goal here was just to get "one" working ;-))

I made a movie here, with a good camera this time, of it doing 30 inch hits ;-) (25 MB MPG movie file)


Got to the lower right and click "free". It makes you wait about 30 seconds to read the ads and click off the popups. Then type in the funny letters and download. I have been using www.RapidShare.de a lot so buy everything in the ads and donate to them ;-)) It certainly solves the big file distribution problem!! It is a plain MPG file that even a modern DVD player should play if you burn it to disk...

The little heat sinks get to about body temperature for short runs which is just right according to the calculations. Bigger heat sinks and/or a fan would be good for extended operation.

The full data on everything is here (might take a while to DL since it is 'busy" ;-)):


I still need to finish this up, but it is up to date as of last night. Let me know, off list, if there are any errors or something I should add or polish up. It was written in parts, very fast ;-) But it is the best way to document stuff like this. A far cry from the OLTC :o)))

Nothing has blown up yet and everything seems perfectly happy. The only bug was the DC MOT charging which I had to whip up a high voltage blocking inductor for. But that was a mundane typical MOT coil issue.

You have to be careful to turn up the variac until is just starts to run smoothly (120 BPS) and no more. If you turn up the voltage too high, the BPS rate can go up dramatically and overheat the IGBTs. Higher BPS does not seem to increase spark length other than making them sound funny. Sort of "screetchy".

Thanks for everyone's help, input, and encouragement!!! Looks like we all have a new toy :-))))

BTW - The dual MOT system has an extremely dangerous primary system!! Be very careful when working on them especially now that there are electronic circuits and stuff in there to fiddle with. Be ultra sure that the power is off before working on them. Be very careful of the output arcs since it is possible for a primary to secondary break over to present lethal currents on the secondary. Note too that the primary circuit can be almost at full power, but totally silent!