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Re: Foil wound pancake secondaries.



Original poster: "RIAA/MPAA's Worst Nightmare" <mike.marcum-at-zoomtown-dot-com> 

I guess it depends. I'm building a dc resonant coil that uses 60kv, 250 mA,
500bps at full power.  The tank caps are only .0075 uF (which would be even
smaller if used with  higher voltage lower current like an x-ray
transformer. I have one that puts out ~100kv, 120mA continuous (originally
rated 375mA for it's intended purpose), just waiting to get a good (.1
micron) vacuum pump to repot it in oil)).

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, September 26, 2003 10:10 PM
Subject: Re: Foil wound pancake secondaries.


 > Original poster: "Gerry Reynolds" <gerryreynolds-at-earthlink-dot-net>
 >
 > I would think that the self capacitance of the primary winding would be
 > insignificant compared to the tank capacitance.
 >
 > Gerry R
 > Ft Collins, CO
 >
 >
 >  > At the scrap yard, I came across a nice roll of 2 thou. thick 1 inch
 >  > wide copper strip,(0.05mm*25mm) and so a nice foil wound pancake
 >  > secondary would be possible to make.
 >  > I imagine that oil impregnated paper from cash registers would do as
 >  > insulation. Even with 2thou thick insulation it is possible to make a
 >  > 1000 turns coil that is only 8 inches (200mm)in diametre.
 >  > Drive it from the H.bridge and get some interesting results.
 >  >
 >  > I`m not sure I understand this right, but I imagine that the turn to
 >  > turn capacitance will be much greater in a coil like this, if so, how
 >  > will it affect the performance of the coil.
 >  >
 >  > Cheers, Finn
 >  >   the person who might best be able to advise you is Jeff Behary.  He
has
 >  > built several of these pancake coils.  maybe once rolled, entombing it
in
 >  > wax or perhap some type of potting material would help.   as for the
self
 >  > capacitance,  would that not just lower the resonant frequency?
perhaps
 >  > using several layers of the paper would help lower the inter turn
 >  > capacitance a bit.
 >  > Mike
 >  >
 >  >
 >  >
 >
 >