Re: resonant charging

To: tesla-at-pupman-dot-com
Subject: Re: resonant charging
From: bob golding <yubba-at-clara-dot-net> (by way of Terry Fritz <terryf-at-verinet-dot-com>)
Date: Fri, 25 Sep 1998 22:58:14 -0600
Approved: terryf-at-verinet-dot-com

At 17:40 25/09/98 -0600, you wrote:

>Did you measure the capacitor initially?  What kind of cap is it?  Have the
>plates separated somewhat?  I did some rough calculations and estimate that
>your system needs about 15 nf of capacitance to be in tune when tapped full
>out at turn 9.  With 12 nf, you should need about 10.1 or 10.2 turns on the
>primary.  Can you add another couple of turns to the primary?

Hi Ed,
	My cap is made from A4 plastic wallets (polypropylene) and kitchen foil. I
am using 6 wallets for a total thickness of
30 thou between each layer of foil. I made 3 caps at 53.1 nF and  connected
them is series to give 17.7 nF. I measured the value after they had sat in
the oil for about a week. This came out at 15 nF. I am sure the plates must
have expanded as the first incarnation of this cap cracked the Plexiglass
sides I was using to hold it together so I rebuilt it using  60 thou poly
sheets as side cheeks. I think on my next cap I might make it 20 % higher
in value to compensate for the expansion. I should be able to add another
two or three turns to the primary without major upheaval. 

	Many thanks,

	Bob golding

bob yubba-at-clara-dot-net