Re: Dr Resonances motor is Hysteresis Motor, not Salient Pole Synch motor

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

Original poster: "Darren Freeman by way of Terry Fritz <twftesla-at-qwest-dot-net>" <free0076-at-flinders.edu.au>


Guys,

You should be able to shave flats on a hysteresis motor just as with a 
salient pole motor.

I would get a second oppinion as I've never done it but it should certainly 
prefer to lock with the salient pole below the stator pole.

Maybe not the same repeatability of lock angle, since the rotor is designed 
to have high hysteresis and might retain magnetism from a previous run, to 
lock in a slightly different angle. But the variation should be pretty 
small, I hope! Variable reluctance is a pretty good motivation to synch up 
normally...

Or just swap it for an induction machine and modify that =)

Have fun,
Darren Freeman


At 10:09 AM 18/08/2002, you wrote:
>Original poster: "Daniel McCauley by way of Terry Fritz 
><twftesla-at-qwest-dot-net>" <dhmccauley-at-spacecatlighting-dot-com>
>
> > Dan,
> >
> > You unfortunately may have a hysteresis sync motor.  This type
> > locks into a different position every time it starts, and everytime
> > it loses lock.  You need a salient pole sync motor.  These can
> > be bought, or made, by modifying a normal induction motor, by
> > grinding flats onto the armature.....  2 flats for a 3600rpm motor,
> > 4 flats for an 1800 rpm motor.  The width of the flats should be about 1/4
> > the armature diameter.  If you have an 1800 rpm motor, and it shifts
> > 90 degrees when loses lock and re-locks, that would be normal.
> > If it locks to any a spot at any random number of degrees shifted,
> > then it's a hysteresis motor.  You can use a hysteresis motor,
> > but you have to adjust the phase every time you use the tesla coil.
> > This is usually inconvenient, so folks usually avoid the use of those
>motors.
> > One fellow flips the motor switch on/off a few times until it happens
> > to phase up good enough for the coil to run.  I don't favor that
> > technique however.
>
>
>After careful inspection of the motor, I believe I do have a hysteresis sync
>motor.  It even says it right on the label:
>HYST SYNCH MOTOR.  I realize i do need a salient pole synch motor and Dr.
>Resonance did claim that the motors
>he was selling was true salient pole motors.  He probably didn't realize it
>either at the time.  Oh well . . .
>
>Dan