Alt-BEAM Archive
Message #01825
To: beam@corp.sgi.com
From: Robert McIntosh robmc@acay.com.au
Date: Fri, 26 Mar 1999 17:45:37 +1100
Subject: [alt-beam] Re: small parts....
>
> Excellent description of the gear boxes (deleted). However this ratio
> may need correction. For an AC motor, the synchronous speed can be
> calculated by the equation:
>
> (120 x f)/P
>
> Where f is the frequency of supply and P is the number of poles. So for a
> motor with 2 poles operating with a 60 Hz supply, 3600 RPM is correct.
> However, usually the motors used in these timers have many more poles(may
> be 20 ?) so they run quite slow. Depending on the number of poles on the
> motor, the gear train may have a ratio of 20,000 (more or less).
> Dilip
Does that formula change with voltage?
Why can't we rewind a small motor to get what we want? I gather it is to do
with the gauge of the wire and the number of turns. The radio controlled
car fanatics rewind their motors to get more torque so.....? The Maxon
motors have the coils moving around the magnets so
Rob
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