Re: Do these numbers look right?

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

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

"Hi Joe,

You could recheck your numbers using JAVATC.  It is very accurate and
has a
wealth of info.  You can use the auto tune feature and experiment.  If
you
do use a larger Cp, you can reduce the number of turns in the primary
and
get it in tune.  If you do stay at resonant Cp (or close to it), you
need to
be diligent on setting the safety gap properly so you don't overvolt the
NST.  With no spark gap firing, voltages above 100KV will probably
happen
(simulation shows up to 300KV)  The safety and main spark gaps are the
only
things keeping this high resonant rise voltage from happening.  With 7nf
Cp
(Cres=6.2nf) and the spark gap set to fire at 18KV, the BPS will be
about
180 (per simulations)."

	I suspect core saturation will keep the maximum voltage to a lot less
than 100 kV, but still high enough to wreck the insulation.  Maybe
someone can sacrifice a transformer and a capacitor to the cause and get
some experimental results.

	A long time ago I wrecked the HV scale on a Simpson 260.  I had a 15
kV, 60 ma transformer hooked to an 0.006 ufd, 30 kV mica transmitting
capacitor (and a TC primary, of course).  For reasons I can't remember I
fed the transformer primary from a variac and advanced the voltage with
the meter on the 1000 volt scale.  At some voltage there was a jump to
very high secondary voltage which blew out the multiplier in the meter.
I decided that what was happening was that as I increased to voltage the
core inductance actually increased until it was resonant with the
capacitor, resulting in the jump in voltage.  Point is that core
saturation can affect the resonant properties of an NST.

Ed