Re: air bubbles (fwd)

---------- Forwarded message ----------
Date: Wed, 20 May 1998 00:12:02 +0300
From: Harri Suomalainen <haba-at-cc.hut.fi>
To: tesla-at-pupman-dot-com
Subject: Re: air bubbles (fwd)

>I am in the process of building one of two large capcitors that I
>will use in series on the new coil I'm building. The problem is two of
>the six sheets of poly I ordered have small air bubbles in them. Does
>anyone know If this will cause the cap to breakdown? I'm using two

It will cause problems. Depending on size and shape of bubble the
electrical field in the bubble is many times the field on insulator.

The answer is that instead of normal 20kV/mm (PE) you might
need to derate it to perhaps 2-4kV/mm or it will fail pretty soon.
Note that air is better insulator than this :)

Harri Suomalainen     mailto:haba-at-cc.hut.fi

We have phone numbers, why'd we need IP-numbers? - a person in a bus