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From: sharpe@mecad.uta.edu (Todd Sharpe)
Subject: Re: How does a brushless DC motor work? WAS: Looking for brushless DC ...
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Bill Morrow (morrow@cns8.cns.ucalgary.ca) wrote:
: How does a brushless DC motor work, anyways? Don't you need some kind
: of varying field (e.g. a commutator, or AC voltage) to start the rotor
: spinning? I know little about 20th century motor design :).

The rotor (the center spinning part) is usually made up of rare earth 
permanent magnets (if the motor is worth anything). The field is produced 
in the stator on the outside of the rotor in wire windings and rotated 
through electrical commutation.  Since the field is rotated electrically, 
no commutator is needed and therefore no brushes.

--
_________________________________________
|Todd Sharpe                            |
|sharpe@mecad.uta.edu                   | 
|The University of Texas at Arlington   | 
|MSME                                   | 
|_______________________________________|
