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Re: Variacs, HV Jell, and LTRS Caps
At 04:07 PM 5/16/99 -0600, you wrote:
>Original Poster: Terry Fritz <twftesla-at-uswest-dot-net>
> Also, I am working on a new MMC cap design that will require that they be
>submersed in oil. I am running them above their ratings (in the "enhanced"
>mode :-)) taking advantage of the fact that "I know things" :-)) Since oil
>is such a mess, I was wondering if mixing mineral oil and say paraffin
>would produce a jell that could be heated to flow but would solidify like
>grease when cooler? The jell would not be a dielectric but more of an
If we consider mineral oil to consist of relatively light hydrocarbon chains,
and parrafin to be longer, heavier chains of the same basic repeating
structure,
then petroleum jelly is the intermediate step between the two, being a mix of
molecular chains shorter than parrafin, but longer than mineral oil. It's also
in the "jell" form you're after. Parrafin, petroleum jelly, and mineral oil
are
all mutually soluble, and you can melt petroleum jelly together with mineral
oil in a double boiler to produce a much lighter, but cheaper insulating
jelly.
I've done this in the past to produce a non-leaking insulating oil bath. One
word of caution though -- it doesn't take a lot of heat to melt petroleum
jelly, destroying its viscous advantage over mineral oil. I've sadly no
experience yet with MMC caps, and don't know how warm they get. Operating in
open air may give a deceptively low first guess because of air convection.
In any case, if warmth may be a problem, then petroleum jelly/parafin may be
the answer to retain viscosity when things get warm. You may want to
experiment
with small samples and "design" for the melting point you're comfortable with.
Wes B.
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