Re: Cap Question

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

Original poster: "Christopher Boden by way of Terry Fritz <twftesla-at-qwest-dot-net>" <chrisboden-at-hotmail-dot-com>


>Original poster: "Soul Firez by way of Terry Fritz <twftesla-at-qwest-dot-net>" 
><soul_firez-at-hotmail-dot-com>
>
>
>Hey,
>Im looking for capps on ebay and i keep seeing doornob caps and big oil 
>caps
>(the ones in the big cans with the terminals on top) and i was wonderring 
>if
>these would be appropriat for coil use?

Some are, yes. Doorknobs tend to drift in value as they heat up, and also 
crack. They don't tolerate overvoltage too terribly well either. The big 
metal cans are usually industrial PFC caps and unsuitable for coiling (you 
need HV Pulse caps). Even if the cap is of the right type and voltage, in 
coiling (where overvoltage of the cap is quite common, especially among 
newbie coilers) those nice big metal pulse caps almost universally become 
nice big metal doorstops in what is never a long enough lifespan :) The cap 
could last you for 5 years, or 5 minutes, you have no way of knowing.

I have a growing collection of these old caps myself :) Anyone else out 
there who would like to get rid of your old metal caps when you go MMC (EVEN 
IF THEY'RE DEAD! ((((ESPECIALLY IF THEYRE DEAD))))) We'll take them! :) I 
use them for classroom demos.

The MMC cap is the current state of the art in coiling. Stable value, 
tolerates repeated overvoltage, and completely variable to be as unique as 
your coil (for such a simple things, I have yet to see two duplicate coils, 
they're like a fingerprint). They also have the nice benifit of being 
inexpensive. $3 get's you .15uF at 2kV, and we sell them to coilers by the 
thousands.

>
>Thanks
>Brad
>
>P.S. if anyone knows where i can get caps for a mmc for really cheap please 
>let
>me know

http://www.thegeekgroup-dot-org/Flash/Sales/MMCsales.html

btw, yes I know our website is acting weird lately and changing daily. We're 
revamping the website (it's growing...again) and have to go to a database 
driven design, so expect things to change a lot in the next month or so. Now 
that the Thon is over I can work again :) When the site settles down I'll 
let everyone know so they can update their links.




Christopher "Duck" Boden Geek#1
President / C.E.O. / Alpha Geek
The Geek Group
www.thegeekgroup-dot-org
Because the Geek shall inherit the Earth!