Re: RSG's

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

Original poster: "Stephen Conner by way of Terry Fritz <teslalist-at-qwest-dot-net>" <steve-at-scopeboy-dot-com>

At 05:19 30/05/03 -0600, you wrote:
>Original poster: "Rodney Goolsby by way of Terry Fritz 
><teslalist-at-qwest-dot-net>" <jeronimo-at-bright-dot-net>
>
>I'm just wondering, what is the difference between a SRSG and an ARSG?

A SRSG is driven by a synchronous motor, that is always 1800 or 3600rpm (or 
1500/3000 if you live in a 50Hz country) On the other hand an ARSG is 
powered by an induction or brush-type DC motor (universal motor). If you 
use a universal motor you can achieve very high rpm like 12000 or more, 
which might give better quenching but is more likely to fly to pieces and 
hurt someone :(

>One of my future designs for my first rotary gap was to first find a 
>suitable motor, then to make a disk (size depends on motor), put in some 
>electrodes (number based on motor rpm), and drive the whole thing with my 
>130v 5amp variac. Am I correct in assuming this is an ARSG?

You choose whether to use a ARSG or SRSG depending on your power supply. 
For NSTs you need a SRSG since the ARSG can cause nasty voltage surges. The 
optimum break rate is 120bps (or 100 in 50Hz land)

MOTs, PTs, pole pigs, and DC supplies can use either. These power supplies 
are usually used with high break rates, say 400bps. At these high rates the 
SRSG doesn't have much advantage over the ARSG.

Of course pole pigs etc. might well work even better at 120bps. I believe 
the Oklahoma 'BIGGG Coil' uses two pole pigs and a 120bps SRSG. You need a 
humongous tank capacitor to achieve full loading at these low break rates 
which is why most people opt for the high bps ARSG instead.

Steve C.