Re: SSTC theory

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

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

Tesla list wrote:
 >
 > Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz>

 > I think matching to the base of an unloaded resonator is a most
 > fruitful approach in a number of respects:
 >
 > - noting that a capacitor that is running down in a traditional
 > disruptive system still continues to pump the secondary until it is
 > empty (given ideal k for this to happen), I see no reason why a drive
 > system operating in what is effectively CW mode should ever suffer
 > the phase reversal inherent in the traditional endpoint of energy
 > transfer.

The phase reversal appears in the system designed for a resistive
load, if the load is removed. The reason is that the excitation is
not at one of the resonances, but somewhere between them. I made
some plots. See in:
http://www.coe.ufrj.br/~acmq/tesla/sstc.html
If the excitation is moved to one of the resonances, there is no
phase reversal during the output voltage rise, but in both cases
the designed maximum voltage is reached in approximately the same
number of cycles. Actually, the faster rise without load is obtained
by excitation at the central frequency, and not at the resonances.

 > - the way appears to be open for machines to be built to generate
 > enormous voltages in the MV range with very high storage energies to
 > boot with a rather modest drive system (Greg?)
 > - the ISSTC is a system where shooting for a *high* secondary Q
 > really comes into its own.

Not necessarily:
The ratio between the effective load resistance and the input
resistance determines the maximum voltage gain:
Vout/Vin=sqrt(Rload/Rin).
But as the excitation frequency and the inductances can be chosen in
a wide range, the Q for a good secondary don't have to be necessarily
very high. In my example, that converts 229 V to 114.6 kV, a
voltage gain of 500, the Q of the secondary is just 8.5.

 > - by carefully shaping a breakout point, one can tailor a given
 > secondary to let go before it destroys itself. In fact one can
 > progressively shape it to restrain further and further as confidence
 > rises. A bit like opening up the gap in fact.
 >
 > I expect the matching to be not-too-critical given the self-adjusting
 > drive frequency together with the transformation of MOhms to a few
 > tens of Ohms by Zo^2.
 >
 > Again, none of this is really that new. Sloan's CW system worked in
 > much the same way.

Even Tesla tried to build "forced response" coils, by using fast
gaps, and Fessenden's high frequency generators for radio transmitters
were just this same thing.

Antonio Carlos M. de Queiroz