# Re: [TCML] MMC design

so the voltage rating is more important that how close I am to the calculated capacitance?
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I know that the mmc calculators have ratings for the voltages. and I would make the assumption that since I can tune things, I dont have to be exact on the capacitance, correct?
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thanks

Paul...
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----- Original Message ----- From: <resonance@xxxxxxxxxxxx>
```To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Sent: Wednesday, January 16, 2008 11:07 AM
Subject: Re: [TCML] MMC design

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Good engineering design calls for Erms x 2.5, so at 9 kV Erms x 2.5, would
equal 22.5 kV.  Dividing 22.5 kV / 2 kV MMC value = 11.25, so best to use
12 MMCs per string, then parallel as necessary.

Dr. Resonance

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```I'm going through some of the MMC calculators on the net trying to figure
this stuff out.
I have a 9kv NST and LTR capacitance is 12.5nF
output of the NST is ~13kv p-p   (close enough)
so, assuming 0.1 2kv caps
1 string of 8 = 16kv and 13nf
2 strings of 16 = 32kv and 13nf

is 16kv "high enough" above the NST?
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is it just a waste to go with 2 strings of 16, should I, in this scenario,
```stick with 1 string of 8 and call it good?
if the caps were 0.047 and 2kv, then 2 strings of 8 = 16kv and 11.75nf
or 3 strings of 11 at 22kv and 12.82nF

which is more important in designing the MMC?
is it more important to be as close as possible to the LTR value or have
enough voltage "padding" above the xmfr? is there some other factor in
here
to use (like the discharge energy or something?)
thanks

Paul (I didn't expect the Spanish Inquisition) in Michigan...

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Dr. Resonance

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