RE: Reducing Self Resonance In Rolled Caps

To: tesla-at-pupman-dot-com
Subject: RE: Reducing Self Resonance In Rolled Caps
From: "Lau, Gary" <Gary.Lau-at-compaq-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Tue, 15 Feb 2000 20:08:15 -0700
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

I don't believe that the ESL (equivalent series inductance for the
acronym-challenged) in a tank cap is a real problem in our Tesla Coil
application.  There was a thread on this List about a year ago discussing
the issues surrounding off-axis primary inductance.  The bottom line was
that off-axis  inductance really doesn't compromise performance, it merely
slightly reduces coupling.  I believe the same argument applies to a
capacitor's ESL.  

Nothing can prevent self-resonances.  Your primary coil has its own
self-resonant frequency, and so does every piece of wire in your tank
circuit.

Regards, Gary Lau
Waltham, MA USA

>Original Poster: "William Parn" <parn-at-fgm-dot-com> 
>
>I am still very new and learning, however here goes.
>
>I have heard a lot about rolling caps, however there also
>appears to be size limitation due to self resonating
>qualities of rolled caps.  Can we just roll them using
>extended foil design so as to prevent self resonance?
>
>What I mean here is to extend the foil out 
>the top of one plate and then extend it out the bottom
>of the other plate.  Roll it up and then bring all 
>the foil at the top together and make a connection
>then do the same at the bottom.
>
>Has this been tried?
>If yes, What are the results?
>Would this prevent self resonance?
>
>Many Thanks,
>Bill Parn