Re: SRSG?

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 9/2/02 10:14:47 AM Eastern Daylight Time, tesla-at-pupman-dot-com
writes:


>
> I have seen the results of Ed's exparaments, god is it amazing.  What's the
> trick with a ARSG, you have to time it with the phase of current, while a
> sync will always be in phase?



Calvin,

Using an ARSG, one does not worry about phase at all.
The gap fires at constantly changing spots along the 60Hz
ac power sine wave.  Sometimes the cap will be fully
charged, sometimes less than fully charged.  It doesn't
matter, it's all energy that's being fed to the streamers.

There's nothing magical about sync rotary gaps.  They
simply give a repeatable cap charge voltage, so they're
especially good for getting the most power possible from
NST systems which can fail if over-volted.  The biggest
danger to NST systems from ARSG's is if one slows
the rotary so much that firings are skipped, and the
voltage builds too high.  This will only occur in matched
(resonant systems).  With the advent of LTR arrangements
for NST systems, NST failure with ARSG's should be less
likely, although not much work has been done lately in
this area.  Another reason that SRSG's are used with
NST's is because it permits more power throughput, and the
the low bps seems to give superior spark lengths.

In a pig or PT system, where transformer failure is not
likely, the ARSG can be used with interesting results.
The arc characteristics will vary with the breakrate,
and the sound of the coil will change.   Usually, the
voltage sags as the motor rpm is raised, thus the
arcs do not lengthen very much as the break rate is
raised.  Each coil will behave differently here though.
Much depends on the relative capacitor size.  Small
capacitors will need a higher breakrate to obtain a
reasonable power throughput and spark length.

For any given coil, a smaller capacitor will demand
a higher breakrate for a given spark length, assuming
a constant voltage.  There are two basic ways to increase
the spark length from a given coil;  1) increase the
breakrate,  2) increase the bang size.  Of course if
the breakrate is raised, but the transformer cannot
deliver more current, then the voltage may sag, and
no spark length gain will be achieved. 

In work I've done, I've seen better overall "efficiency" using
a large bang size combined with a low break rate.....
as compared to a smaller bang size combined with a
higher breakrate.  If this is indeed true, then it's because
of the characteristics of spark growth in air.  These
characteristics have not yet been adequately studied.
A lot more work is needed in this area.

A small capacitor, high breakrate system can give
a longer spark relative to the resonator length and toroid
size.

John