Re: Energy storage in primary?

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

Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz <teslalist-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>

Tesla list wrote:
 >
 > Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>

 > In that case, it would be exactly like a typical coil.  Remember, you can
 > either charge the cap to say 20kV and close the gap. Or, you can drive 1000
 > amps through the primary circuit and open the gap.  Either way works and
 > they are theoretically identical.  It's just hard to run 1000 amps and then
 > have the current source withstand 20kV of RF voltage.  We are talking a
 > 20MVA switch there!!  Spark gaps do that easily for voltage drive.  Current
 > drive is not so easy.

The equivalence between the two systems is not exact, since one can't
be made to operate exactly as the other. The "magical k values" are
different, and the tuning relation too.

Tying a design:
For round numbers, 60 W of input power at 120 bps:
"bang" energy: 0.5 J = 0.5*L1*I1^2
Limiting I1 at 20 A, L1 = 1/400 = 2.5 mH.
Now it's necessary to chose an adequate C1. We can use the approximation
that is to consider that all the energy is transferred to C1, that will
produce a conservative voltage over C1:
0.5*C1*V1max^2 = 0.5
With V1max = 1000 V, C1 = 1/(1000^2) = 1 uF
The operating mode 1:3, the fastest for complete energy
transfer, requires (L2C2)/(L1C1)=2.33 and k=0.756.
With a load capacitance C2 of 100 pF, L2 = 58.5 H.
With all assembled, the circuit resonates at 1.83 kHz and 5.5 kHz
(1:3 ratio), and transfers energy in 136 us. The maximum output
voltage reaches 20 A *sqrt(L1/C2) = 100 kV.

Note that the resulting values looks as parameters of an
induction coil.

Antonio Carlos M. de Queiroz