Re: Poly Caps

At 11:25 PM 12/5/96 -0700, you wrote:
>>From alfred.skrocki-at-juno-dot-com Thu Dec  5 23:08:31 1996
>Date: Thu, 5 Dec 1996 02:59:01 EST
>From: Alfred A Skrocki <alfred.skrocki-at-juno-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Poly Caps
>On Mon, 2 Dec 1996 22:39:26 -0700 Tesla List- Mike Hammer
><mhammer-at-midwest-dot-net> writes:
>>I built a cap in beer bottles and had fair success with it. It
>>got me sparking until I built a flat plate poly cap. The poly cap 
>made a BIG difference.
>   Mike, I was experimenting with polyethylene plate capacitors a
>while back. Even though polyethylene has a low K it has very good
>dielectric strength, which means smaller spacing between the
>plates and consequently higher capacitance per volume than most
>other dielectrics! I built one polyethylene cap out of 6 inch
>square sheets about 1/8 inch thick. I used copper sheeting for
>the plates and submerged the whole thing in mineral oil held in a
>plexiglass tank I built for it. It's performance was the best I
>ever had compared to glass caps or even mineral oil caps! What
>was the construction like on your poly cap?
>                                 Sincerely
>                             Alfred A. Skrocki
>                          alfred.skrocki-at-juno-dot-com


I made 6 separate caps with 6 X 6 plates of heavy duty aluminum foil.
Each cap had 24 plates. Dielectric was 2 layers of 4 mil poly.
The 6 individual units were wired in series to achieved a higher
voltage rating. It sets in a homemade tank made from plywood with
a plexiglass inner liner. Took a little over 1.25 gallons of oil.
The final capacitance was a little over .008 mfd.
So far it has performed well on my coil at a little over 1.5 KVA.
Power is 12kv neons.

I planning a bit more ambitious cap for a winter project.
I would like to do a .0125 mfd cap with a 30 KVAC rating.
Lots of work but I have more time than money.

Mike Hammer