Re: NST TEST GRAPHS (was NST power test)

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Original poster: "Sean Taylor by way of Terry Fritz <teslalist-at-qwest-dot-net>" <taylorss-at-rose-hulman.edu>

I think someone already mentioned this, but there is going to be a huge
difference between the steady state analysis of just an RC load on an NST
and the transient that occurs when a spark gap fires in a tank circuit for
an NST with a capacitive load.  There is also a difference between where the
capacitor is in the circuit and where the gap is.  With the gap across the
NST, during gap conduction a current flows in the through the current
limiting inductance of the NST, and stores up energy, upon the quenching of
the spark gap, this energy is then dumped into the tank cap, and the gap can
fire sooner than just the time that S.C. current that the NST would provide.
If understanding how an NST reacts to a TC circuit is what is trying to be
accomplished, then some time domain analysis needs to be done.  Terry, I
believe you have closely monitored the secondary current of an NST while a
coil was running.  A scope plot of tank cap voltage and NST secondary
current would be interesting for a 120 bps case, with a controlled gap such
as a TSG firing at the peak of the tank cap voltage.  Has this already been
done?  Perhaps also the voltage and current from an NST simply being shorted
by a TSG without a tank circuit hooked up would be useful.  The gap would
have to be quenched rather quickly, but it would show what happens to the
voltage from the secondary of the NST directly after gap quenching, or
rather what it would "like" to do, since in a TC tank circuit it is loaded
down by the tank cap.  A lot of this could be done in SPICE, but maybe some
real testing would be more fun :-)  Not to mention that all the parameters
for simulating an NST are not all the same, and several NSTs could be tested
this way rather easily.

Sean Taylor