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RE: The 1500t secondary myth



Original poster: "Steve Conner" <steve.conner@xxxxxxxxxxx>

>The fact that the optimization curve seems to have a fairly broad flat peak
>keeps the faithful faithful and the skeptics skeptical.

I quite agree with this. If my (or I guess it should be "Our") deductions on
Zo are true, then there seems to be about a factor of two spread (ie from 25
to 50k) inside which you get good performance. Greg Leyh's coil that gave
25ft at 25kW (which btw is just above what John Freau's efficiency equation
predicts) has the lowest Zo I've seen of any serious performing coil.

As for the OLTCII with its 90k Zo.. Steve Ward, Jimmy H. and I did a
comparison where we all ran our coils at 100 bps and 6 joules energy. I
forget the exact figures but I think they got 41-43" and I only got 39"
which is really not much of a difference.

The one thing that could sink this theory big time (if it's true) is the
late Marc Metlicka's 3000 turn coil. This would have a Zo much above 36k
unless it had a 2" former or a topload the size of a two bedroomed house.


>The output voltage of any coil system is dependent on turns ratio and Q of the >resonant circuit and amp turns input to the primary curcuit. BUT dont tell >any one that or you will get abuse from these strange members.

The output voltage of a coil is determined by the square root of the ratio
of secondary capacitance to primary capacitance.

BUT, in a practical coil, Lpri*Cpri must be equal to Lsec*Csec, or it will
be out of tune. Therefore it's equally valid to say that the output voltage
is determined by the square root of the ratio of the inductances. And since
the inductances are a function of the numbers of turns, I agree with you so
far.

However the inductance also depends on other things (like coil diameter) so
it's not quite as black and white as you make out. With *SSTC the crap
really hits the fan and the output voltage has very little to do with
anything ;) I use PSpice simulations to predict it.


Steve C.