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Re: Home-brew Capacitors
In a message dated 12/15/98 5:20:27 AM Central Standard Time, tesla-at-pupman-dot-com
writes:
>
> 1) It's been a while since posts have been made about proposed home made
> dry (no oil) caps made by connecting a bunch of them in series to minimize
> corona and breakdown in the individual sections. Has anyone achieved good,
> long life results yet? If so, many of us would appreciate the particulars.
>
Steve
I have made one cap. dry, about 3 months ago for a small magnifier using a
10 kV -at-23 mA ignition transformer. Still running with no problems. It is a
prototype with a capacitance of 0.005 uF. 10 individual caps. using 3 mil.
poly from Walmart and 3 mil. printer paper. It is a flat plate with the foil
ends of one cap. folded over the next cap. and stapled (for use with low power
only).
Many other caps. were built as much as 1 1/2years ago using oil saturated
paper only. No oil bath. These have run with 10 kW and are still running
good. The purpose of the oiled paper was to be able to squeegee the air out
one layer at a time and permit good adhesion for the paper, foil and poly.
(maximum capacitance) These all used 3 mill poly, paper and regular foil.
The foil ends of each flat plate cap. were folded over and a paper hole punch
used to allow #10 machine screws and nuts to connect them together. The
biggest one made so far is a 0.05 uF.
I had also better mention, the last 2 oil caps used corn oil as it will not
warp the poly. like mineral oil will.
>
> Bottom line - building caps is a major undertaking. If people discover
> better ways to do it, please share.
>
Bottom line, building caps. is monotonous, (poly,paper,foil...poly, paper,
foil...etc....etc....etc...) time consuming, easy to make a mistake that will
ruin the whole cap. in one "bang".
>
>
> Kevin E.
>
>