Re: Foil wound pancake secondaries.

["Tesla list" <tesla-at-pupman-dot-com>]

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
 >
 >
 >