Re: More ISSTC theory stuff

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

Original poster: Ed Phillips <evp-at-pacbell-dot-net> 

" >Very interesting.  I myself have a lot of experience with designing
  >microstrip versions of 1/4 wave transformers and similar.

Sorry, I think this needs some more explanation. Here is my theory...

In a ISSTC, the secondary is a 1/4 wave transformer and the primary is
an
L-match. The fact that they are inductively, rather than directly
coupled
complicates things, but not much. (The inductive coupling can be
modelled as
an ideal step-up transformer, as Antonio showed in his diagram, and
Richie
Burnett explains on his site)

Anyhow, a 1/4 wave transformer is equivalent to a L-match, at its
resonant
frequency. So if we are modelling the ISSTC at resonance (and since it's
a
feedback system, it will ALWAYS run at resonance) then we can picture it
as
two L-matches, OR two 1/4 wave transformers, with the inverter at one
end
(stepped up by that ideal transformer) and the streamer load at the
other.

If you use PSpice you will end up modelling it as L-matches with lumped
components, since PSpice didn't have a transmission line resonator
model,
last time I looked."

	I disagree with a lot of this discussion, at least insofar as it calls
a top-loaded secondary a "quarter-wave transformer".  No way!  The
typical top-loaded secondary has an almost constant current distribution
and therefore must be considered as an inductor, not a transmission
line.  The only transmission line which has a constant current (or
voltage) distribution is one terminated in its characteristic impedance
and is thus equivalent to a transformer with a ratio of 1.

Ed