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Re: Blown Rolled Cap

tesla-at-grendel.objinc-dot-com On Wed, 27 Mar 1996 11:01:57 +0700, you
wrote:

>>From richard.quick-at-slug-dot-org Wed Mar 27 01:23 MST 1996
>>Received: from uustar.starnet-dot-net (root-at-uustar.starnet-dot-net [199.217.253.12]) by uucp-1.csn-dot-net (8.6.12/8.6.12) with SMTP id AAA07554 for <tesla-at-grendel.objinc-dot-com>; Wed, 27 Mar 1996 00:44:18 -0700
>From: richard.quick-at-slug-dot-org (Richard Quick)
>Subject: Re: Blown Rolled Cap
>Date: Wed, 27 Mar 1996 01:11:00 GMT
>To: tesla-at-grendel.objinc-dot-com
>
>Quoting jim.fosse-at-bdt-dot-com (Jim Fosse):
>
>> I just took apart my first blown cap. 1 layer of 0.060" 
>> polyethylene. Identical failure!  Both look as if a sharp point
>> on the edge of one of the plates punched thru the dielectric. 
>> Both holes were 1.5' to 2' in from the inside of the roll.
>
>> I had sanded and smoothed both cap's plates and used my fingers
>> as roughness gages.
>
>Having done this more than a few times on different capacitor
>designs I can tell you the sharp raised points were most likely
>not there when the capacitor failed. It is the energy released at
>the instant of failure that distorts the plates; frequently you
>will find holes blown clear through the plate, but if there was
>insuffient energy to completely hole the plate, a sharp rasied
>point will often be formed in the plate during the failure.
>
>Richard Quick
>
>
>... If all else fails... Throw another megavolt across it!
>___ Blue Wave/QWK v2.12
>
>
Richard,
	Thank you for the reply. Is there a learning curve for
building caps? Or to properly phrase that, how big is the learning
curve for building ones own pulse discharge caps?  I'm debating with
myself on the classical build/buy decision. I'm leaning toward build,
right now for the knowledge I'll gain.

	respectfully,

	jim

p.s.	the irony of my situation is: 2 weeks ago I ordered 3 pieces
of test equipment to allow me to do more precise measurement of my
coil system. The money I spent would have bought 1 and 1/2 of those
fine commercial cap. I can now measure my system but, not run it:(

	jim