On 2/2/2011 7:12 AM, Josepi wrote:
I think you would find the field does **NOT** rotate but rather attempts to
stay in the same place relative to the field coils.

Think about that one...LOL


"Dan wrote in message
...
A 'brushed' DC motor uses brushes and a commutator to vary which windings
are energized to create the rotating magnetic field.Dan

I am not going to bother to try to straighten out your annoying top posting!


However as I said in the very next sentence of my posting (which you snipped):

"The windings are usually on the rotor and the rotor's magnetic field rotates
backwards relative to the rotor."

Yes. In the typical brushed DC motor, the backwards rotation of the rotor's
magnetic field results in a field which is stationary relative to the stator
field.

My point is that the magnetic field of either the rotor or the stator or both
has to change (relative to what is causing the field) to cause the motor to
move. In a brushed DC motor it is usually the rotor's field. In a brushless
DC motor it is typically the stator's field. In an induction motor is is
typically both.


Dan