Re: phasingsrsg

["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 4/22/02 7:18:24 PM Eastern Daylight Time, tesla-at-pupman-dot-com
writes:

Colin,

Run the motor with a cardboard or other disc attached to the 
shaft.  Draw a heavy black or white line across the disc to
provide contrast.  Observe the running motor under normal
fluorescent light.  The light will cause a strobing effect which
will show if the motor is locked.  This will create a visible
pattern on the spinning disc.  The pattern will be very fuzzy,
and some folks have trouble seeing the pattern at first, but
it's there.  If the pattern is spinning, the motor is not locked.
The pattern must appear to be stationary.  If you have a variac,
use it to vary the motor speed.  At some lower voltage the
motor will unlock, and the pattern will rotate, then as you
raise the voltage, the pattern will become steady again,as
the motor locks sync-ly.  You'll also hear an unsteady 
sound when the motor voltage is a little to low to lock.
This is called a hunting sound, meaning it's trying to lock.

There's just about a 100% chance the motor will sync-lock
properly in sync mode since you modified it.

Cheers,
JOhn

>
> hi 
>     im trying to tell if my motor is running in syncronous mode iv machined
> the
> armature with two flats so im hoping now it will run at 3000 rpm but i dont
> know if its syncronous how can i tell without expensive strobe lights and the
> such
> the motor is out of a cloths dryer the gap runs ok on my 6.25" coil but not
> sure if its quite right
> many thanks
> colin heath