Re: synchronous motor

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "resonance" <resonance@xxxxxxxxxxxx>


No, it's not really --- takes about 8 seconds to bring it into 
sync.  You run it at full speed, bring up the variac.  If it's not in 
sync your sparks will be much shorter, so then just flip the motor 
switch off/on for 1/2 sec, and then bring up the variac again.  After 
1-2 tries it's in sync.  Also, it does get into proper sync 
automatically usually 70% of the time --- only rarely do we have to 
use this procedure.

We usually just go with non-sync motors.  If you use a standard 4 
electrode RSG rotor, with a good Terry filter, keeping the pulse rate 
under (180 pps), it works fine.  Our unit has been running for nearly 
4 years in a museum, used 4 times a day x 6 days per week, on the 
same nst.  We did use a new nst so it was in optimum condition prior 
to deployment.  With nsts we use only a 4 pole rotor running at 1725 
rpm on a 7 inch dia phenolic rotor (6 inch electr. center to 
center).  25% spark length gain over a standard copper pipe air gap.

Dr. Resonance

> That sure sounds like a pain in the other side of your lap.....with 
> all your resources,  you don't have a vendor for easy-to-get  rotory 
> gap motors?    If not,  I'd go with the DC charging circuit  design.
> Mike