RE: Exact design for lossless SSTCs

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

Original poster: "Steve Conner" <steve.conner-at-optosci-dot-com> 

 >The objective is to apply an alternating voltage to the input,
 >and after a determined number of cycles have all the energy that
 >entered the system in Cb, without voltage in Ca or currents in
 >La or Lb.

Thanks for your post Antonio, this is very interesting. The "sinusoidal
input" case sounds almost identical to what Jimmy Hynes was doing
(semi-empirically) with his original DRSSTC.


However, if I remember right, Jimmy H. found that he got better experimental
results when the oscillator was retuned to coincide with the lower split
frequency. I suppose this would correspond to a:a:b or whatever, except that
the b mode would hardly be excited at all.

I think that DRSSTCs actually function better when one mode is excited far
more than the other, and hence Ca and Cb are both fully charged at the
instant of breakout. If the drive is kept on through breakout, then none of
the energy in Ca can return to the DC link, hence it all must feed into the
discharge.

In other words I believe the energy left in Ca is not a "loss" but actually
contributes to the sparks. Hence a DRSSTC driven in this way should give
twice the bang energy (for a given capacity of MMC bank) of a DRSSTC that is
optimised for complete energy transfer according to the theory you posted.
It may not give the fastest energy transfer, but the energy transfer rate is
limited by how much current the semiconductors can stand anyway.

Following on from this, if I were trying to make a SSTC magnifier, I would
use the mode relationship

a:a:b:c

where b and c are "Don't care". So of those four simultaneous oscillations,
two (the drive frequency and the lowest frequency mode of the coil system)
would be at the same frequency and the other two would be minimised.

Steve C.