cornell caps

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

Original poster: "Matt Skidmore by way of Terry Fritz <twftesla-at-qwest-dot-net>" <fox-at-woozle-dot-org>

i was going through the list archives (which seem to work well through the
google search) looking at the information on the cornell dubilier caps
that i have seen on the company's website, along with the caps the geeks
are selling. ive gotten somewhat confused on the issue on what type of
capacitor was good to use. cornell has the 942C which reaches a peak
voltage of 2kv, while the 940C which has a higher voltage of 3kv.

what has me confused is the following message segment:
The 940C looks like they just have metal film electrodes and the 942C has
solid metal foil electrodes.  They both list pretty high dV/dT but the
metalized electrodes do not make solid connections to the end caps which
is what cooked Garry's caps.

my current understanding is that the 940C 3kv caps have a weak internal
connection which casses them to burn up inside.

while we're on the subject, from what i've read, mylar caps tend to heat
up also and go AWOL. I think i acutally used these types of caps for my
first coil. they held up for several stunning runs before they did
literally "light up."

all admit that the geek caps are offered at a good price. i couldnt find
the exact caps for sale online, but i found the 0.1 uf cap for $1.97 in
batches of 50. a BIT cheaper of you consider uf per dollar, but i'd still
buy from the geeks. too bad i didnt get them while they were $2.50

-matt