Re: oil for caps

From: 	gweaver[SMTP:gweaver-at-earthlink-dot-net]
Sent: 	Friday, January 02, 1998 12:26 PM
To: 	Tesla List
Subject: 	Re: oil for caps

>> If the primary dielectric material of the cap is polyethylene with a K of 2.0
>> to 2.3, using a high dielectric constant oil will not raise it.  The cap will
>> measure the same - or very close, with either type of oil.

I used the formual C = [(.224 x K x A) / d] x 2

C = pf

d = distance between plates in inches

A = area of one plate in sq. inches

K = 2.3 

Plates are 10" x 108 inches with 18 layers of .006 mil poly filled with HV oil.

I don't remember K for polyethylene.  I designed my capacitor to be .01 uf
not figuring the oil would make any difference in K.  

After the capacitor was finished I used a capacitor tester to check it.  It
checks out to be .0103 uf.  I did not test it without oil.

I worked the formula backwards with C = .0103 and found K to be 2.3

I have build 7 capacators and used K = 2.3 for each.  When I tested each
finished capacator each one was right.

.0015 uf tested .00146 uf

.005 uf tested .00501 uf

.01 uf tested .0103 uf

Gary Weaver