How does a DC motor work without a commutator?

AI Thread Summary
A DC motor can operate without a traditional commutator by utilizing the forces of attraction and repulsion between the rotor and magnets, allowing it to continue spinning once initially set in motion. The initial spin provides the necessary momentum to overcome the magnetic attraction at certain points in the rotation. Some users report successful operation of such motors, suggesting that they may incorporate a different form of commutation. Understanding the mechanics behind these motors is crucial for effective construction and operation. Overall, the discussion emphasizes the importance of initial momentum and the alternative methods of achieving commutation in these motors.
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How can this DC motor work without a commutator. Should it not turn no more than once and then stop because on one side the rotor is attracted to the magnet?

An answer I can think of is that the rotor is repelled on one side and attracted on the other by the same force which neutralize each other so what counts is the force you give it in the beginning when you spin it with your hand. Or is it the momentum that gets it over the being attracted part of the circle? What do you think?

It works very well. There are many videos and I tried it myself.
simple%20motor.jpg
 
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That motor does have a commutator of sorts. I'm guessing when you tried it, it didn't work.

If you had actually built this, and it worked, you'd know how the commutators function is accomplished.
 
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