Re: Unexplained arcing current

To: tesla-at-pupman-dot-com
Subject: Re: Unexplained arcing current
From: Gary Lau 25-May-1999 1022 <lau-at-hdecad.ENET.dec-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Tue, 25 May 1999 11:29:41 -0600
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

I believe I've figured out why my resistors get so hot.  Well, almost.

Recapping, with my tank circuit disconnected so that my 15KV/60mA NST
just fires my 0.36" static gap through my RC protection network, the
series resistors (1.6K/113W non-inductive film) get hot very quickly, but
if I disconnect the 450pF bypass caps, they do not.

I realized that with my tank cap no longer in place, the bypass caps will
charge many, MANY times per mains half cycle.  I quick simulation showed
that if the static gap were set to 15KV, it would charge and discharge
128 times per half-cycle.  The RMS current through the resistors is over
250mA!  That will do it!

Only problem is, I also have this hot resistor problem to a similar
degree when my tank circuit is in place and the bypass caps may only
charge the same number of times as my main cap does, a couple of times
per half-cycle at most.  Still looking...

Gary Lau
Waltham, MA USA