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Re: MMC Survivability

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

Hi Jim,

Cp = 100nf  (10 strings of 15 per string).

Vpeak = 20400 so Ipeak will be 20400/sqrt(Lp/Cp) need Lp to solve but if I assume 50uh (my primary is 70uh), Ipeak = 912 amps Your MMC will be good for 4320 amps.... OK

Assume Irms is 912/1.414 = 645amp rms during energy transfer. Assume energy transfer is 50us (1st notch quenching) out of a BPS period of 5ms. So Irms = sqrt (645^2*50us/5ms) = 645 * sqrt (50us/5ms) = 64.5 amps_rms. Your MMC is good for 135 amps rms.... OK

Note, if 2nd notch quenching Irms = 645 * sqrt (150us/5ms) = 111 amps so still OK

You are operating at 20400Vpeak and the MMC is rated for 30000Vpeak.... OK

I think everything is fine if you provide sufficient cooling. Actual RMS during ring down will be less cause it does ring down. Second notch current wont be as high as first notch current. Many of the presentations will be at less than peak voltage and some of them won't even fire. So the rms current prediction is really awfull worst case. Just monitor the temp rise until your comfortable with the operation.

Gerry R.

Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>

Hello all,

I'm building a 12" coil powered by a 5KVA 14.4kv
(pushed a bit). I had hoped to buy one of Dr R's
Maxwell super caps but the buy won't go through until next spring.

What do you think the survivability of 10 rows
(.1uf) of CD942C .15uf, 2000kv x 15 strings and a
200 BPS ASRG will be, since I have that many?

Thanks, I suspect it would be on the edge.

Jim Mora