Re: Phase controller question.

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

Original poster: "gtyler" <gtyler-at-drummond-dot-org.za> 

You don't actually say that you have 4 flats, but if you only have 2
that will explain everything. That is a 4 pole motor, so there is a pole
every 90 deg on the rotor. With 2 flats you insert a huge air gap in the
magnetic circuit tthus increasing the magnetising current drastically,
also causing vibration if the flats are not 100 % perfect.

George

 >
 > > >Well that's good that you've modified other motors, so you're
familiar
 > > >with the process and the results.  Did the armature and coils seem
 > > >more or less like a normal induction motor?  I guess you ground 2
flats?
 > >
 > >Hm, the windings looked a bit different from what I saw before, but
this was
 > >my first 1500rpm motor.
 >
 >
 > Oh, I thought you had said it was a 3000rpm motor.  So I assume you
 > made 4 equal flats for 1500 rpm?   Was it a 60Hz motor rated at 1750
rpm or so?
 > Of course that probably won't cause a problem on 50Hz.
 >
 > >There are 4 ( visible )windings, each covering 1/2 of the stator,
thus
 > >overlapping 1/4 stator diameter.
 > >The rotor is about 7 or 8 cm thick and I ground something like 2cm
wide
 > >flats IIRC.
 >
 >