Re: SRSG or ARSG

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

Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com> 


To add to John's comments:

NST's are designed to develop 12-15 kV for 1/4 sec to ignite the neon in the
glass tube.  After ignition it drops back to 200-300 volts and provides a
steady 60 mA current to keep the plasma glowing bright.  They never were
designed to provide continuous HV especially in the tar insulation many of
them use.  Any RF at all gets fed back into the NST and they die.  Terry
Fritz's nice filter design helps keep them safe.  Also, always calculate the
resonant value (xmfr Z = Xc).  For stationary sparkgaps multiply this value
by 1.6 to keep your cap slightly larger than the resonant value.  For
synchro RSG (120 pps) this multiplier value can be extended to 3.2 x
calculated resonant value.  This is possible because the transformer isn't
working as hard trying to recharge the caps to fire at 300-400 pps.  We've
gone as high as 3.4 in a test design, but the NST's seem to be happier
around 2.8 to 3.2 x resonant value.  Careful phasing of firing point of the
synchro RSG is important for optimum performance.

The ideal NST design for TC work would be a core/coil assembly that can be
dropped into a tank of oil.  I'm working on this solution at present and
hope to offer a nice 16 kV design at 250 mA --- with a shunt that can be
moved depending on the amount of current you need to power the caps.  I
envision a phenolic top to which the xmfr core/coil is attached on short
extension tubes so that the xmfr is lowered into the oil when the top is
attached.  I would fit a small plug that could be used for vacuum evacuation
to get all the bubbles out.

The shunt would be adjustable from 100 mA to 300 mA to adjust current to fit
the cap value.

With luck this project will be done by Mar 04.

Dr. Resonance

Resonance Research Corporation
E11870 Shadylane Rd.
Baraboo   WI   53913
 >
 > >May ask why exactly an ASRG is bad for an NST?
 >
 >
 > ASRG can be used, but must not be run to slow or the
 > voltage may go to high for the NST if a suitable safety gap
 > and protective filter is not used.  However the spark lengths
 > will probably be poor.  A small value cap must be used, which
 > will not permit the NST to deliver much power.  Many folks
 > run the ASRG slow at times without adequate protection
 > and destory the NST.  Only 120 bps sync will give the
 > ultimate in spark length performance with NSTs it seems.
 >
 > John
 >
 >
 >