Re: ASRSG question

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: FutureT@xxxxxxx 


David,

You mentioned setting the electrodes as close as possible.
How close was that?  In some cases for small coils I've had to run my
electrodes almost touching (just a few thousands of an inch).
I'm not recommending that for your case however because
if tungsten runs too close, the electrodes tend to break off
if they strike each other.

Nevertheless folks such as Richard Hull often used a series
multiple static gap in series with their rotary and still didn't
have a problem despite the wider total gap spacing.  Are you
using a static gap in series with your rotary?  If such is used
and has too-wide gaps it will cause a problem.

In a 120 bps system, the firing voltage may be somewhat
higher so it may make it easier for the gaps to fire.  Still,
many folks use 2 or 4 gaps or more with ASRG systems,
and don't have the problem you had.

Maybe the problem is that you are only using
two electrodes on your rotor.  This requires a very high
motor speed to get a high break-rate.  These speeds
may make it difficult for the rotary to fire if the electrodes
are narrow in diameter.  Lower speeds may
give erratic firing as the system semi-phases in with the
input ac power 60Hz waveform.  ASRG users often use
8 or 10 electrodes on their rotors, and run at a lower RPM.
I remember Bob Svangren once mentioning that he tried
using 6 spinning electrodes instead of the normal 8, and
his system failed to work at all.  Perhaps it gave him a too-low
breakrate.

Wider electrodes (such as 1/2" dia) will tend to fire more
reliably because there's more time available for firing during
the mechanical dwell time.  Usually 14.4kV doesn't give a
problem.  Folks who use 7.2kV may need to set their
gaps somewhat close.

The particular capacitor value that's used along with the
ballasting inductance value also affects the firing voltage
and can be a factor in gap firing.

So anyway I've presented some ideas for consideration above.
I'm not sure though exactly what's happening in your system.
Regarding the 180 degree electrode positions, such a gap
may run cooler, and make it harder for the electrodes to fire
maybe.

Cheers,
John Freau