RE: Toroid Capacitance : WAS: 12" Metal Spheres

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Original poster: "Mccauley, Daniel H" <daniel.h.mccauley-at-lmco-dot-com> 


Its more than theory.  Its a fact.  To get longer arcs, you need large
terminal capacitances.  Its based mostly
on the fact that smaller top loads will break-out prematurely well
before the theoretical resonant voltage rise
of the coil.

Going from a 12" x 3" Toroid on my 3.5kW coil to a 30" x 7" Toroid, i
get spark increase from about 2.5 feet to almost 7 feet!

Also, one particular coil that is impressive is Richard Hull's 11E
Magnifier.  He used an enormous toroid (50" diameter)
on top of a 13" x 4" secondary coil wound with 30 AWG wire and managed
over 10 foot arcs!!!

Toroids also work better than spheres since they shield the top of the
secondary from hv discharge.  A very large sphere
due to its geometric shape will tend to arc to the primary much more
than a toroid of the same capacitance.

Dan



 > 	OK.  That's the only difference I can think of too.  Of
 > course, a
 > sphere with a breakout point is another way to go.  I have a kind of
 > theory here that the more topload capacitance the better
 > (lower resonant
 > circuit L/C and hence surge impedance) but haven't thought
 > about how to
 > prove that.  I do know that going to toroidal upper terminals sure
 > revolutionized "the business"!
 >
 > Ed
 >
 >
 >