Re: SRSG?

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

Original poster: "Wells Campbell by way of Terry Fritz <twftesla-at-qwest-dot-net>" <wellscampbell-at-onebox-dot-com>

Hi Calvin, 

SRSG's are synchronous, that is, they are linked directly to the line
frequency. Depending on the motor speed and number of electrodes, they
will fire at some multiple of the frequency of household AC supply. The
most common application is to have them fire at 120 times per second
(100 for 50 Hz systems) this enables the transformer to charge the caps
fully  each half cycle, then discharge them at some optimal point, which
remains constant from one cycle to the next. The phase adjustment everyone
talks about is basically when during the cycle the gap is set to fire.
I don't have too much experience with these systems, so I won't go into
when that may be, but it is somewhere near the peak of the cap's charging
cycle, so that the maximum charge will be blasted through the primary
and into the secondary. From what I understand, coils using neon sign
transformers work well with SRSG's. 

ASRG's are not tied to the line frequency, and are usually variable.
most are designed to cover a wide range of break rates, and can reach
high breaks per second. Mine at full speed fires 1200 times a second.
 A popular misconception is that they are inferior to SRSG's, when in
fact they are much better for certain types of systems, specifically
DC powered coils. Most DC coils supply a constant voltage to the cap
instead of one that cycles from negative to positive and back 60 times
a second. This aspect frees the user to fire the cap whenever, and if
the cap charges fully and stays charged each time until the gap presents,
the power throughput can be controlled by the breakrate. Also, different
streamer behavior and characteristics determined by high and low breakrates
can be observed using such a system. See Richie Burnett's webpage for
more than you'll ever need to know on the subject, www.richieburnett.co.uk

The reason ASRG's are not good for line frequency dependent systems is
that at certain breakrates, especially those near the line frequency,
the gap will fire at varying points along the cycle, producing beat frequencys,
resulting in chaotic firing, missed firings, overvolting of the caps,
and can be very bad for the NST's. Ever tune a guitar? when the two strings
are near tune, but not in tune, you hear a distinct beating as the sounds
constructively and destructively interfere. This plays hell with a coil.
ASRG's are ok for AC coils, as long as they fire many times per cycle,
preventing the situation where the gap doesn't fire for at least a half-cycle,
but this usually means that the cap doesn't get charged all the way,
and the bangs aren't as big. 

Anyway, enough for now. I'll let someone else give you the snoop on motors,
as I'm not so well versed on types, etc. but there are copious posts
in the archives detailing methods for converting many common motors to
synchronous operation. 


Hope this helps...


-- 
Wells Campbell
wellscampbell-at-onebox-dot-com



---- "Tesla list" <tesla-at-pupman-dot-com> wrote:
> Original poster: "Calvin Patrick by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <linhacktux-at-wycol-dot-com>
> 
> What does one look for in a motor for use in a SRSG?  What are the
> advantages of a SRSG over a ARSG?
> 
> _________________________________________
> Calvin Patrick
> ICQ#: 125694645
> More ways to contact me: http://wwp.icq-dot-com/125694645
> _________________________________________
> 
> 
> 
>