Re: Please help with capacitor

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

Original poster: "John Richardson" <jprich-at-up-dot-net> 

Hi,

Jeff Larson has a beautiful coil that utilizes a homemade cap that he and
Bert H. built, and it performs flawlessly and for long run times.  I
personally have seen it run at several T-thons over the last several years,
and it's still going strong.  He's also got a super cool adjustable while
running copper static gap.

John Richardson


 > Original poster: Esondrmn-at-aol-dot-com
 >
 > In a message dated 1/6/04 10:24:56 PM Pacific Standard Time,
 > tesla-at-pupman-dot-com writes:
 >
 > Dan,
 >
 > I have made several rolled poly caps as well, many years ago when I first
 > got into coiling.  You certainly can make rolled poly caps that will
 > survive and work well in service.  If adequately designed, they take up a
 > lot of room, require thick dielectric layers (or several in series) and
 > don't produce many microfarads at our voltage level per cubic foot - if
you
 > know what I mean.  I started out with one dielectric layer of .0625".  Two
 > of these worked well at 12 kv rms when used in series.  Both failed when
 > used in parallel at 12 kv.  I rebuilt one with two layers of .065 poly and
 > seems bullit proof but is low on capacitance.  My opinion is 4 layers of
 > .020" poly or 3 layers of .030" poly is required to work at 12 kv.  I
would
 > question the reliability at 15 kv.
 >
 > Ed Sonderman