Re: Is this motor synchronous?

From: 	Rick Holland[SMTP:rickh-at-ghg-dot-net]
Reply To: 	rickh-at-ghg-dot-net
Sent: 	Wednesday, December 24, 1997 12:12 AM
To: 	Tesla List
Subject: 	Re: Is this motor synchronous?

Tesla List wrote:
> Is it possible for a motor to be synchronous but at an arbitrary and
> variable phase?  Is this motor unsuitable for a sync RSG, or is my
> analysis technique flawed?
> Gary Lau
> Waltham, MA USA

It is, indeed possible for a motor to have a fixed rpm that has nothing
to do with the input frequency. Using a feedback network, it doesn't
matter where in the phase the motor starts, as long as it's maximum (and
minumim) rpm is that specified. This, by definition, is not synchronous,
but *fixed* rpm. As far as suitability, it is definitaly suitable as
long as you mount the motor so that it can be rotated to synch with the
input voltage. This will require that you have some method of comparing
the rotation with the input phase. A strobe comes immediately to mind.
In the worst case, (perhaps the best) you simply start the system and
rotate the motor until you have best spark output. The downside is that
this operation will have to be performed every time you turn on the
system. The main thing to remember is that this thing is switching
leathal voltages. Be safe!


	Rick Holland

	The Answer is 42.