PT's in series (was 110KV BIL?)

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

Original poster: "Ray Haynes by way of Terry Fritz <twftesla-at-uswest-dot-net>" <ray.haynes-at-home-dot-com>

Bill is your statement about not running the PT's in series based on the VA
ratings and how the higher voltage will cause higher current thus
overloading the PTs?

If I was to run more turns on the primary and a smaller capacitance but
higher voltage cap (keeping the same primary resonate frequency), would that
take advantage of the higher (28.8KV) voltage without overloading the PTs?
Also with a smaller cap and higher voltage that appears to lower the current
in the primary reducing I squared R losses.

I have some foggy memory about a Tesla's coil output voltage going up as the
square of the primary voltage (think I read it on this list). Or has the
thinking changed? That would be the only reason why I would want to run them
in series.

I'm thinking if this wasn't true then why is everyone messing  with all this
high voltage on the primary in the first place? Just run a few hundred volts
with big caps and a one turn primary with a large copper bar. Of course
there would be problems switching the very high current pulse but
empirically it seems to indicate that a larger primary voltage is better.

Just wondering,
Ray
Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<wysock-at-ttr-dot-com>

Ray,

BIL stands for "basic impusle level".  It is an IEEE standard, for
impulse voltage level (withstand) peak voltages in a (simulated)
lightning strike.  Whereas the insulation of a P.T. may have a
110 KV BIL rating, unless you have an (unususally large) P.T.
i.e., larger then a nameplate rating of 1,500 VA, I would NOT
connect two units in series (on the high voltage side).  14.4 KV
is more then ample to drive any medium-sized Tesla coil
	<SNIP>
Best regards,
Bill Wysock.