DC Motors Question (1 Viewer)

[robbo845]

What would happen in a simple dc electric motor if you changed the current to AC and why. Thanks in advance

 

[rawrence]

A DC motor uses a coil in a permanent magnetic field, a split ring commutator is used to reverse direction of current every half revolution, if you supply AC then you reverse direction of current 50 times a second. It won't spin and it won't work

 

[Amogh]

To my understanding, it will oscillate back and forth in accordance with the frequency of the AC supply.
A DC motor is made in such a manner such that the split ring commutator reverses the flow of current every half a revolution (and ensure a constant direction of rotation). AC current reverses it's direction periodically regardless. So as the AC current direction changes, the split ring commutator would reciprocate the direction - meaning that a constant direction of current is maintained. Momentum of the coil should keep it moving in a certain direction untill the AC current changes direction.

 

[robbo845]

So if AC current changes direction 50 times per second there would be no way to ensure that it changes direction at the same that the coil(rotor) has completed a half turn, and subsequently you would have a sporadic motor rather than a continously freeflowing one?

 

[OmmU]

So if AC current changes direction 50 times per second there would be no way to ensure that it changes direction at the same that the coil(rotor) has completed a half turn, and subsequently you would have a sporadic motor rather than a continously freeflowing one?

Yes, it will appear to be still and not moving.

 

[sameerali]

when dc electric motor current is changed from DC to AC, it will stop working.