Re: mmc caps...working voltage.

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "BunnyKiller by way of Terry Fritz <twftesla-at-uswest-dot-net>" <bigfoo39-at-telocity-dot-com>

Tesla list wrote:

> Original poster: "hoggwild89 by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<hoggwild89-at-netzero-dot-net>
>
> Designing my coil (or, 'the money pit' as my wife refers to it) I am using
> two 15000 v transformers, parelled. Still 15kv (obviosly),
> but am i correct in my (mis?) understanding that I should design the
> parameters of the cap around a 30kv 'working voltage' to withstand the
> pounding
> that its going to get....or is this just a waste of money ?
>
> Shop online without a credit card
> http://www.rocketcash-dot-com
> RocketCash, a NetZero subsidiary

Hi HW....

design the cap for 22KV or higher ( up to 30KV )  this will be an added
security to keep from blowing
the caps.

most caps are rated for DC voltage and since we primarily use AC we need to
up the total voltage due
to the AC rating is normally quoted as an average or RMS rating.  The caps
will see a peak to peak
voltage that is higher than what the "normal" ratings of the nameplate of
the transformers.

example...    a NST has 15KV on the name plate  therefore we should build
the cap to 22KV
we use the magic formula of    Volt rating ( normal or RMS) / .707
15000/.707 = 21216V


Altho....   the MMC cap can take a beating and thus, you can build it to
transformer volt rating (
even using DC ratings on the cap ) just be sure to use metalized polypro
caps   see Terry's page for
better info.

Scot D