Re: Success with PP Multi-Mini Cap

To: tesla-at-pupman-dot-com
Subject: Re: Success with PP Multi-Mini Cap
From: "Reinhard Walter Buchner" <rw.buchner-at-verbund-dot-net> (by way of Terry Fritz <twf-at-verinet-dot-com>)
Date: Sun, 25 Apr 1999 22:56:12 -0600
Approved: twf-at-verinet-dot-com

Hi Dave, all


Dave wrote a loooong time ago:

>Original Poster: David Trimmell <davidt-at-pond-dot-net>
>I am far from a expert, but the use of MMC for large disruptive Tesla
>coils, would I think, be more inefficient, due to resistive losses?

Why do you think the MMC would be inefficient (resistive losses)
in high powered DW-TCs? Most commercial pulse caps are not
just a single unit (although they are in a single case), but rather
a string of caps in series (being similar to the MMC construction).
The really big pulse caps (湩 range) are built exactly the same
way the MMC is built (series/parallel configuration).

What I think is most important, in constructing a MMC, is to use
many (series) strings in parallel to keep the current per string
low and use high quality caps that have a high dv/dt rating.

My Philips MMC used MKP X2 caps (Series 336/2) rated for
250Vac. I tried a two string configuration at a low 300W input
power. I seriesed 35 caps, so the total voltage was well below
the rated 250Vac (170v/cap). Yet, they died almost
immediately, even though Philips claimed a 2000Vac/cap/2sec
test rating. What I didn愒 look at was the dv/dt. These caps had
a very meager rating of only 200V/usec. That愀 why they died.
My ERO MMC is holding up quite well and I sure am not being
kind to it.


Coiler greets from germany,
Reinhard