RE: Microwave oven fan motors

["David Dean" <deano-at-corridor-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Hi

Not being one to leave well enough alone, I tried it. Modified a small fan
motor from a small Microwave oven. It locked in sync OK. Put a universal hub
on it, had to wrap the shaft with a couple layers of tape to make it fat
enough to hold the hub, (it is a small motor) and still it stayed in sync.
Then I put a cover off of a tape box on to simulate a rotor. (3M 33+ comes
in a small box of polypropylene with a cover, about 3 1/2" in diameter) That
was to much for the poor little motor. This motor has a 1/2" stack. Perhaps
a larger motor with a 1" stack would turn a 3" disk of 1/8" G-10 OK.

The question remains how small of a rotary spark gap would still be usable,
that is when does it quit being a rotary break, and just become a rotary
power arc.

Perhaps I'll look into this further, if I can find a bit larger motor of the
same type amongst my junk.

later
deano


> -----Original Message-----
> From: Tesla list [mailto:tesla-at-pupman-dot-com]
> Sent: Wednesday, August 30, 2000 8:14 PM
> To: tesla-at-pupman-dot-com
> Subject: Re: Microwave oven fan motors
>
>
> Original poster: "Ed Phillips" <evp-at-pacbell-dot-net>
>
> > Induction motors do suffer slip and their speed is roughly
> > proportional to Fmains and inversely proportional to the
> > number of poles.
> >     Shaded pole motors are non-synchronous right frmo the word
> > go. The shorting copper bands are a cheap way of simulating a
> > start/run winding. They are terribly inefficient compared with
> > a good induction motor.
>
> 	Is this subject worth the discussion.  Those fan motors are tiny and
> probably incapable of driving any decent-sized rotor.
>
> Ed
>
>
>