Re: Sync Motor Wanted

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

Original poster: "Gerry Reynolds" <gerryreynolds-at-earthlink-dot-net> 

Hi Jim,

There certainly does seem to be some controversy on this subject.  I will
comment on computer simulations of an SRSG at 120 PPS vs a STATIC gap at 120
BPS.

For the rotary, if the Cp is set to 3.1* Cres, then a SRSG will allow you to
fire after peak (can't do this with static gaps) and use the inductive kick
to still charge the Cp to full voltage.  With a static gap, the max Cp that
can be charged to full voltage at 120 BPS is 1.6 * Cres.  Therefore, with a
SRSG you can get twice the bang energy at the same BPS.

Now, if you allow overvoltage (maybe iffy with NST's) by using a Cp smaller
than 3.1 * Cres, then it can be possible to draw more REAL WATTs from the
NST than its VA rating.  The cool thing about running at 3.1 * Cres is if
there is a misfire or phasing problem, the voltage reduces (it takes firing
at the optimum time to keep the voltage up there).  If the rotary quits all
together, the voltage will automatically drop to 1/2 of normal (steady state
response of the circuit).

I do believe that an SRSG does have the potential to outperform a static gap
and one does have more knobs to control to help that happen.  You can reduce
the Cp slightly to make up for losses in the system and reduce it even
further to set the level of overvoltage that you are willing to permit.
Some people use a Cp that is too small and then count on the phasing to keep
the voltage from firing the safety gaps.  These systems, I believe, are less
than optimum and one should always have enough Cp to prevent the safety gaps
from firing independent of phasing.

One persons opinion :-))
Gerry R

 > Original poster: "Jim Mitchell" <electrontube-at-sbcglobal-dot-net>
 >
 > Hi John,
 >
 > I'll be running a 15/120 supply consisting of two 15/30's which have been
 > deshunted and put in parallel.  From what I hear ASRSG kill NSTs very
 > easily...  Does the SRSG really increase spark length/performance that
much?
 >
 > Regards - Jim Mitchell