Hi,
At 11:05 PM 8/8/2006, you wrote:
Hi Gerry,
You are, of course, mathematically correct. I was attempting to 
come up with an easy to visualize, intuitive explanation for 
someone who is enthusiastic, but to whom the math and theory seem 
to still be somewhat of an amorphous cloud. IMO, Ipeak = Vfire / 
sqrt (Lp/Cp) is anything but visual or intuitive, but it certainly 
IS accurate as long as R ~ 0.
Matt D.
For some strange reason, when I wrote up the Tesla coil formulas thing I used:
Ipeak = Vfire / sqrt (Lp/Cp)
Instead of  the more proper form:
Ipeak = Vfire x sqrt (Cp/Lp)
That was corrected a while back:
http://hot-streamer.com/temp/FormulasForTeslaCoils.pdf
In the case of the SISG, primary resistance is very important since 
we are using giant primary caps, small value primary coils, low voltage etc.
So the equation then becomes:
Iprimary = Vfire x SQRT(Cp/Lp) x EXP(-R x t / (2 x Lp) x SIN(t / 
SQRT(Lp x Cp))
That equation is used to find primary resistance buy comparing to 
digital scope captures too.
http://drsstc.com/~sisg/files/BigSISGCoil/Qcalc.pdf
I suppose one could take the differential and find the first zero 
slope point for a closed form for peak current with 
resistance....  But that would make my brain hurt ;-))
I am sure you wanted to know all that :o)))
Cheers,
        Terry