Re: Magnifier topload size?

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

Original poster: "Edward Wingate by way of Terry Fritz <teslalist-at-qwest-dot-net>" <ewing7-at-rochester.rr-dot-com>

Tesla list wrote:

 > Original poster: "Greg Leyh by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
<lod-at-pacbell-dot-net>
 > The top electrode on Electrum consists of 30 1.5" stainless steel rings,
 > sized to form a sphere of about 85" OD.  The gap between the rings is about
 > 1.75".  The sphere appears to breakout between 1.2 and 1.6 megavolts,
 > calculated from secondary current waveforms.
 >
 > Given a dielectric strength of air of 25kV/cm, an ideal sphere of this size
 > would be able to hold off about 2.7 megavolts.  Of course if Electrum's
 > sphere were ideal, the coil wouldn't fire at all... the secondary can't
 > generate that much voltage.
 >
 > I'd argue that the capacitance of Electrum's sphere is very close to that
 > of an ideal sphere, since the electric field a short distance from the
 > outer surface would be very nearly the same.  An isolated sphere 85" in
 > diameter would have about 120pF, and the total Csec of Electrum (including
 > secondary sheet capacitance and ground proximity effects) is around 135pF.

Hi Greg,

Didn't you also construct a toroid for Electrum using stainless tubing or 
was that for your
previous coil?

Ed W.