Re: Ryobi Bench Top Grinder ?? In Sync??

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

Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 5/20/03 10:02:56 AM Eastern Daylight Time, 
tesla-at-pupman-dot-com writes:

>Can anyone recommend a website for me to learn more about why grinding flat
>spots make a motor synchronous?  I have never fully understood why this
>works.  I am very curious!


Ryan,

The flats create lobes, poles, or bumps (call it what you want),
and this lets the magnetic field "grip" the poles and lock to them,
instead of slipping under load as in a normal induction motor.
The compromise is that a sync motor cannot provide much torque
without losing lock.  In contrast an induction motor will provide
more and more torque as it's loaded down.

A 3600 rpm motor gets 2 flats, an 1800 rpm motor gets 4 flats, is
the basic rule.

John