Re: what capacitor for TC...other newbie questions

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

Original poster: "Rick W by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rickwilliams404-at-earthlink-dot-net>

Ok, will do.
I'm building the NST protection circuit to the letter you suggested in
another (thread?). Ordered all parts from Digikey. I've found it's ALWAYS
best to heed the advice of the experienced! :)

I'm a newbie to the list and found it full of great info.

Rick W.



----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, July 06, 2001 7:53 PM
Subject: Re: what capacitor for TC...other newbie questions


> Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
>
> Hi Richard,
>
> At 09:36 AM 7/7/2001 +0800, you wrote:
> >What are the thoughts on metallized polyester?
> >I have 4 .022uf -at- 16000vdc. These can be found at Allied Electronics:
> >http://www.alliedelec-dot-com/catalog/pf.asp?FN=571.pdf
> >
> >Though it's a DC spec there is no polarity on these caps. No AC spec is
> >provided but it would be less than the 16Kv DC rating.
> >
> >
>
> Polyester has a dissipation factor about ten times higher than
> polypropylene.  This means that they will run about 10 times hotter given
> the same RMS current.  Since Tesla coils are super hard on caps, this 10X
> heating is a killer.  Tesla caps really need to me made from the lowest
> dissipation factor materials available to have a chance of surviving in
> this extreme duty.  Also, "metalized" caps have poor end terminal
> connections that tend to burn out with 1000 amps spikes like Tesla coils
> may create.  You really need metal "foil" caps that use solid metal foil
> for the electrodes.  There is a list of known good/bad caps at:
>
> http://hot-streamer-dot-com/TeslaCoils/MMCInfo/good-bad.txt
> http://hot-streamer-dot-com/TeslaCoils/MMCInfo/mmcinfo.htm
>
> We are very picky about the caps used in MMCs.  I try and test them pretty
> hard*.  They have to be some of the best available.  They are not cheap
but
> the Geek Group's prices are very good!
>
> *http://hot-streamer-dot-com/TeslaCoils/MMCInfo/GeekCaps/GeekCaps.htm
>
> Cheers,
>
> Terry
>
>