Re: THOR: First observations on streamer formation (try II)

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

Original poster: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br> 

Tesla list wrote:
 >
 > Original poster: Marco.Denicolai-at-tellabs-dot-com

 >  > If you can synchronize a camera and the "bangs", you could look at
 >  > how a streamer forms and grows.
 >
 > We are working on arranging $$$ for that. We are talking about >35000$
 > money. Last year I applied for four scholarships to buy a fast camera,
 > got none :(

I was thinking on a camera that could take one picture per bang. You
can also use several inexpensive cameras, taking pictures in sequence.

 >  > Have you seen my comment about a different tuning for a Tesla
 >  > coil that
 >  > increases the voltage gain beyond that 18% increase described in your
 >  > RSI paper?
 >
 > No. Where?

In 27/1/2004. Repeating the essential:

After a discussion with Jim Lux, I wrote an "optimizer" program for
the lumped model of a Tesla coil during the energy transfer transient:

     +--R1--+        +--R2--+
  +  |      |        |      |   +
Vc1 C1     L1 <-k-> L2     C2 Vc2
  -  |      |        |      |   -
     +--<---+        +-->---+
       Il1             Il2

The program calculates exact solutions for the transient that starts
with an initial Vc1, and tries then to optimize the circuit following
several criteria.
One of the possibilities is to generate the maximum possible output
voltage.

It's well known that it's possible to detune the coil, increasing
C1 or decreasing C2, sacrificing complete energy transfer and
efficiency, and obtain a small increase in gain before the
detuning forces a fall. Adjusting k too allows a slightly
larger gain. The objective is to obtain the maximum gain with
-the same coils-. (The new maximum gain sqrt(C1/C2) is not reached.)

The largest voltage gain reported is with T=0.541136 and k=0.545659,
what generates Vc2/Vc1=sqrt(L2/L1)*1.1802. T=(L2*C2)/(L1*C1).

I was imagining that my program would find this solution. But to my
surprise it found another, better: T=0.479222 and k=0.593349, that
results in Vc2/Vc1=sqrt(L2/L1)*1.19950, at the first negative peak.

This same solution produces a slightly larger positive peak 4
cycles later (*1.19957), and further optimization increases this
peak to *1.2307 with T=0.4603 and k=0.6054.

The optimizer program (optesla) can be found at:
http://www.coe.ufrj.br/~acmq/programs
I wrote also a similar program for a magnifier. They also admit detuned
solutions with greater voltage gain, at the expense of efficiency.

Antonio Carlos M. de Queiroz