Re: MMC Caps

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

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi John,

It is unlikely that voltage is damaging the caps but rather current is.

using the equations at:

http://hot-streamer-dot-com/TeslaCoils/MMCInfo/MMCPower4.html

Ecap = 0.3375 Joules

Rcap = 8.49 mOhm

Wo = 95.25 mW

To = 2 C

So the caps should only heat up 2 degrees C. If we look at the RMS current:

Irms = SQRT (Wo / Rcap) = 3.4 amps.  They can take 8 amps...

So I don't know why your 10 string cap would have been failing?  If you
would want to send me a blown one, I could look at it and maybe figure it out.

Cheers,

	Terry

At 08:35 AM 10/25/2002 -0700, you wrote:
>I have had experience with those 10 string caps from Geek Group.  I just
>blew my third capacitor.  It almost always occurs when I am pulling a white
>streamer to ground, and hence the most current.  Heating is the problem.  In
>my 15kv 90 ma coil, I use two strings of 14, and have had no failures.  The
>single strings seems, like one nomograph I did said, unreliable...  Perhaps
>I ask too much, or as Duck said have tuning problems
>
>That said, they are still the best and most supported product you can use.
>You can get more anecdotal data on them, and real use suggestions than most
>others!  Run light and tune well if you use one string.
>
>John Dyer
>
>www.johndyer-dot-com
>
>
>
>