Re: Cornell-Dubilier caps (was salt water caps or buckets?)

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

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

>Original poster: "Bill Vanyo by way of Terry Fritz <twftesla-at-uswest-dot-net>" 
><vanyo-at-echoes-dot-net>
>
>Tesla list wrote:
> >
> > Original poster: "Christopher Boden by way of Terry Fritz
><twftesla-at-uswest-dot-net>" <chrisboden-at-hotmail-dot-com>
> > Complete plans for a bucket cap can be found at...
> >
> > http://www.thegeekgroup-dot-org/Projects/Tesla/capacitors.htm
>
>I noticed you're using Cornell-Dubilier caps.  I have a bunch of these
>(.047uF 3000vdc) that I was planning on using for an MMC.  Then I found
>a doc on one of Terry's pages (which I can't find now -  it listed
>"good" caps and "bad" caps for MMC's), and the Cornell-Dubilier's were
>the only "bad" cap listed.  I know somebody else on the list used these
>and they blew rather easily.  Are they working for you?  Maybe the ones
>you have are constructed differently - mine are pure metallized film, no
>foil (I unrolled one).

I believe Robin Coprini is using the same ones as we are, and he's got a Pig 
system on his.

Ours came directly from CD (not a distributor) as part of their sponsorship 
of the Group. We've pounded the caps several times and never had a failure. 
They've been run below freezing, and moved dozens of times.

Maybe our MMC is different. I've never seen one built like ours (and having 
spent 4 days drilling holes I know why) most of them are VERY different.
I didn't read Terry's chart (good thing too) and we didn't pick CD, they 
picked us. We begged every cap producer out there. CD was the first to 
accept us for sponsorship. It took us almost a year to get a cap sponsor, 
and it has definately been worth it. After we got the company, Mark Broker 
speced the caps and designed the MMC electrically.
We spent a month scrounging materials (Lexan, resistors, etc) then we all 
got together here at Little St to build them. On the first day we decided (I 
have no idea why) to radically change the design (we were gonna use the 
Coprini design) to the one you see on our site.

I designed the layout of having the caps held in place by their leads and 
floating in open air, the resistors too. I mentioned it while we were 
screwing around with the lexan and we all thought it would greatly help 
cooling, completly elimate arcover, and look radically different than 
anything else out there. The downside is they took FOREVER to build and were 
WAY more labour intensive than they had to be. We wasted a lot of time 
stuffing caps into little holes only to have them all fall out as you tried 
to get the top piece on....ugh.

We have the Pig system coming together now as we get settled into Sigma-6 
and will be testing the caps to their design limits and beyond. I'll let you 
know what happens. So far we have CD caps in 3 of our large cap 
applications. We have the 4 MMC banks without a failire (thank God, it'll be 
impossible to replace an individual cap without a LOT of work). We have a 
room full of electrolytics (250 caps, each 450VDC -at- 1500uF) for our Project 
Thumper. And we have 100 of the 25kV mica caps for the Groucho Project (Marx 
bank). I hope they all survive :)



>
>BTW, your page (listed above) doesn't view under Netscape 4.7
>

lol....that's been an ongoing struggle for 2 years now. We made our site in 
Frontpage and the CSS files are screwy. We are currently in the process of 
recoding the entire site in Dreamweaver and Flash. Within 2 months (we have 
a REALLY big site) it will be done and replace the code-nightmare that is 
our current site.


>	- Bill

Are you a member yet?

Have fun!

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



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