Re: hamfests, rotors, protection

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

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

In a message dated 1/29/01 7:43:40 PM Eastern Standard Time, tesla-at-pupman-dot-com 
writes:

> the motor is about 3.25 inches in diameter mesuring 3 inches deep. the
>  specs i can read are
>  ashland electric inc
>  125 V vy 60 amp .25
>  cat A707EDU-2
>  HYST syn motor RPM 900
>  duty cont mfd 3.0
>  
>  i emailed the manufactor and havent gotten a reply. but from what you said
>  since it is hysteresis it wont work well?
>  
>  ive plugged this baby into the wall and it seems to work good. its about
>  the size of a medium can of beans only not so tall. also i was thinking
>  abuot electrose and people using tungsten. was thinking if people had
>  tried using the center rod out of a spark plug.
>  
>  -matt

Matt,

Well that sounds like a very weak motor to me, since it's only
.25 amp.  It may be able to spin a very light 3" or 4" rotor (PC board).
The problem with the hysteresis design is the motor will have to
be re-phased every time you start up the coil.  This can be done
somewhat easier using the phase shifter circuit, but you might
not always have enough range.  I would not use this motor if I were
you.

The type of motor you want is a salient pole type.  If a motor
doesn't say hysteresis, and it is a sync motor, then it's probably
salient pole.  You can also modify an induction motor to make it
synchronous.

John Freau