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Info about Cockroft-Walton generator (multiplier). Answered

I'm making Cockroft-Walton generators again after some time and some problems I had, and I would like to ask some questions I couldn't answer by myself so I don't end breaking this new one I'm making.

Is it bad to run the multiplier with the sole intention of making arcs? Could the discharge end damaging the diodes? I've been running the ones I created with UF4007 diodes, which have a peak amperage of 30A, now I'm using two BA159 in series (so I can set the voltage up to 2kV), they have a peak amperage of 20A.

If yes I guess there's no easy solution for this, other than to reduce the discharge current or get beefier diodes.

Regarding to the previous question, does the whole capacitor array discharges when an arc strikes, or just the last/lasts one/ones?

Thanks for your time.

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petercdBest Answer (author)2015-02-06

A small accident destroyed all the diodes(1N4007) in mine. I was spinning a tinfoil prop on the live and bringing the neg lead close to make it spin, got a bit too close and the arc jumped the gap melting the tinfoil prop and all 30 diodes.

The purpose of the caps isnt to discharge but to act like one way HV valves.

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Victor805 (author)petercd2015-02-06

I know how that feels like, I had all the diodes soldered to the
legs of the capacitors, every time the diodes failed I had to take them
out as I could. I finally decided to mount the capacitors on that board
leaving some space to change the diodes in case they fail again.

I
thought the first cap would discharge, and then current would flow into
it from the second, dropping the voltage and causing the third to do
the same, and so on...

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iceng (author)2015-02-06

If you look at videos of WCroft they all spark at the same time.

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iceng (author)iceng2015-02-07

Sorry, I was mixed up about the marx generator

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Victor805 (author)iceng2015-02-07

Maybe I'll build a Marx generator in the future, they look more simple and reliable. However I'm still not really convinced by their performance.

I just had the idea of hooking a Cockroft-Walton generator to a Marx generator, that could solve the arc current thing since it would charge the capacitors of the Marx generator with a steady current. The high discharge current would be on the Marx generator, avoiding damaging the diodes.

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Victor805 (author)iceng2015-02-07

I know. Maybe I'm being too skeptical about the current destroying my diodes, maybe the cause for them burning were discharges I assumed were not occurring. I think I'm going to buy a small plastic case to place the multiplier inside and fill it with oil so no discharges can occur. If the diodes fail again then the currents will be to blame.

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