Re: Capacitor materials

To: tesla-at-pupman-dot-com
Subject: Re: Capacitor materials
From: bob golding <yubba-at-clara-dot-net> (by way of Terry Fritz <twf-at-verinet-dot-com>)
Date: Wed, 30 Dec 1998 21:09:11 -0700
Approved: twf-at-verinet-dot-com

At 16:08 29/12/98 -0700, you wrote:
>Original Poster: Sam Barros <sambarros-at-yahoo-dot-com> 
>
>
>  Now with the possibility of a transformer I started looking for
>materials to make a good HV capacitor. So far the only PE sources I
>found were super-thin plastic bags, too small for any actual use, and
>kitchen foil, absolutely useless. I am still looking for it though… I
>have some ideas: For instance, what material are those overhead
>projector sheets made out of? They are just the right size for a good
>plate cap and don’t cost too much… I can’t remember how thick they
>are, but they are relatively thick. They are made out of some type of
>plastic, fairly rigid and it goes white when you bend it at sharp
>angles. HDPE perhaps?

sam,
	I have used those plastic wallets for protecting A4 sheets of paper. They
are made of polypropalene and are very cheap. you can get them from any
office supply outlet in 100's. I used 3 of them  (6 layers) between each
plate and made up 3 caps in series. I am using 9 Kv at 50 mA and they
havent failed yet. The value has gone down and I had problems with them
expanding at first. After that they have been fine for the last 6 months
with running the coil about twice a week  on average for 5 minutes or so.

good luck
bob golding