[Prev][Next][Index][Thread]
RE: Dialectrics in Plate Capacitors
The dielectric requirements all depend upon how large you want your arcs and
how far you open up your gap. I killed two rolled poly caps with a 15/60
NST. The first one used a single .08" dielectric, the second used two .04"
dielectrics in series, both were in oil and the 2x.04" units were vacuum
pumped prior to oil. Both had 1.5" margins. Do not try to economize with
smaller margins. High voltage will surface-track over far greater distances
than an air breakdown, and I doubt silicone will adhere well enough to make
a difference.
Do yourself a favor and forget home-made poly caps, and build an MMC.
Regards, Gary Lay
Waltham, MA USA
-----Original Message-----
From: Tesla List [mailto:tesla-at-pupman-dot-com]
Sent: Friday, December 17, 1999 7:10 PM
To: tesla-at-pupman-dot-com
Subject: Dialectrics in Plate Capacitors
Original Poster: Apollo <ollopa-at-jps-dot-net>
I have two sheets of 60mil 4'x8' HDPE. I need to make a
capacitor for
my 15kv 60ma NST. I'd like to make a .02uf capacitor, but
I'm not sure
if I can. Will I need to put two caps in series to handle
my NST?
Since I have 60mil HDPE, there's no way I can roll a cap and
I've decided
that I'd rather build a stacked plate capacitor anyway. My
research
suggests that I should let the poly hang over the foil by at
least one
inch on all sides, but I don't understand why this is
necessary if I submerge
the plates in an oil with a dialectric strength equal or
greater than that of
the poly. If it won't puncture .06in of poly, why will it
arc from end to end?
What if there was only a quarter-inch of poly overhang that
was sealed with
silicone sealant?
Thanks - Rick Richard