Re: Creeping Sparks and Homemade Caps... (fwd)

---------- Forwarded message ----------
Date: Sat, 25 Apr 1998 12:04:24 -0700
From: "Antonio C. M. de Queiroz" <acmq-at-compuland-dot-com.br>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Creeping Sparks and Homemade Caps... (fwd)

Thomas McGahee wrote:

> A few of my observations:

Excellent post. Thanks.
I have been thinking and experimenting with a way to make dry capacitors.
What I can comment is:
The tabs coming out of the plates for external connections are the worst
problem. The simple presence of the thin plate material coming out of the
assembly produces corona in all directions. It is difficult to charge
a capacitor built in this way to more than a few 10 kV due to corona losses
at these tabs. And the corona to air easily finds a way to the other side
of the capacitor, producing that nasty surface tracking sparks.
Maybe some form of enclosing of shielding of the terminal areas can help.
For example by covering the terminal areas of a flat capacitor with metal
foil, or metal tubes with rounded ends, without any sharp edge of corner.
Departing from the flat capacitor form, a safe structure is a battery of
Leyden jars, made with -solid- connections. It uses more space but is almost
immune to failure.

Antonio Carlos M. de Queiroz