Re: RSG+Airblast = better performance and less current draw

["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 2/21/02 8:01:24 PM Eastern Standard Time, tesla-at-pupman-dot-com
writes:

Greg,

I wonder if the electrodes are so wide that the gaps are "re-firing"
while aligned?  Although this doesn't tend to occur usually at
high BPS.  Another test you can do is to offset one of the fixed 
electrodes, so they barely overlap.  This offset is in the direction
of the rotation.  When offset, one electrode will be just leaving
it's mating electrode while the other is approaching it's mating
electrode.  This reduces the mechanical dwell time.  It would be
an interesting test to try this, instead of the air blast, to compare
the performance.  I tried this on a 600 bps RSG, and it reduced
my current by a few amps, but didn't really help the spark length.
I'm assuming your electrodes are not overheating or running hot
without the air blast?  Overheating can reduce the spark length
and increase the current draw also.  It would be interesting too
to observe your gap firing using a video recording or welders
safety glasses to see if the arcs are trailing without the air blast.

Cheers,
John


>
> On my six inch coil last night, I used an analogue clamp meter to 
> measure the 11kV pole pigs current draw from the wall. It was drawing 
> 16A during normal operation and ~30A when the safety gap fired. Total 
> spark length was 60" with 0.02uF and ~800 BPS. I placed my airblast gap 
> in series with the asynchronous rotary. Spark length rose to over 70" 
> and current draw dropped to 8-10A. I think this is because the air 
> blast allowed better quenching of the spark and reduced the short 
> circuiting of the pole pig.