Re: Overstessing Maxwell caps

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

Original poster: "Crow Leader by way of Terry Fritz <twftesla-at-qwest-dot-net>" <presence-at-churchofinformationwarfare-dot-org>

You do not have a 2x "safety" factor.

Your caps are rated at DC voltages for pulse duty, not RF AC duty. AC volts
time 1.4 does not apply to such instances. There is no hard and fast rule
for this type of ratings conversion of a DC cap to one for AC use, but tend
be fractions of the nameplate ratings.

I suggest for anybody to talk to the manufacturer of their caps for info on
what it the "safe" ranges are for unusual conditions. They all have
engineers that know what the product can or cannot do.

For instance I came across some fun "600v 0.35uF" induction heater caps. I
wanted more info so I called the manufacturer. They had pages of extra info
that was not printed on the label that I was able to use to decide if I
could or could not use in my application. It turns out they were actually
rated 1kVAC -at-35kHZ caps just marked 600 because that is what the customer
wanted.

KEN
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, July 21, 2001 9:25 PM
Subject: Overstessing Maxwell caps


> Original poster: "Steve White by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<slwhite-at-zeus.ia-dot-net>
>
> I have two 0.03 uF Maxwell caps rated at 35 KV each. I was planning to
connect
> them in parallel to obtain 0.06 uF for my pig coil which I am currently
> building. The pig puts out 14,400 volts RMS. I am now beginning to wonder
if
> the 35 KV voltage rating for the 2 parallel caps is enough. I
theoretically
> have about a 2x safety factor. I have been reading that 3x is preferable.
My
> design requires about 0.06 uF of capacitance. Should I go ahead and use
these
> caps (I paid quite a bit for them) or should I sell them and build a MMC
array
> instead? Alternatively, I could turn my variac some to a voltage
sufficient to
> obtain a 3x safety factor.
>
>
>
>