SISG and primary voltage.

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "J. Aaron Holmes" <jaholmes@xxxxxxxxxxxxxxxxxx>

I've been following the SISG threads closely...even
ordered parts to play with!  But my experience is
primarily with classical SGTCs, and my grasp of the
theory largely limited to rules of thumb, so I'm a
fish mostly-out-of-water with all this solid-state
stuff! :-((

In particular, it occurs to me that I now no longer
understand why one would opt for a HV transformer with
SISGs around.  I've got more ~2kV MOTs than I know
what to do with, but why even go *that* high?  Why not
take an OLTC-ish approach and charge the caps straight
from the rectified mains?  With SGTCs, the importance
of quenching and the difficulty of quenching at low
voltages seems to dictate that some amount of HV-ness
is *required*, not just *good*.  With the quenching
argument gone, can somebody attempt to explain (for
the non-EEs among us--me included!) why one might opt
for a HV SISG coil versus a LV one?  I'm sure there
*are* reasons for one over the other (i*i*r losses,
perhaps?), but the factors aren't all obvious to me.
Some people are all about efficiency, but if similar
output can be achieved in the SISG coil by losing the
HV transformer and bearing some IGBT heating instead,
that would also be "cool" :-)

---

Thanks, Terry and company, for proving that modern
technology might actually be able to *simplify* coil
construction :-))  Always thought it had to be so, but
I've seen relatively few examples of it until now.

Regards,
aaron