What does the commutator do in DC motors?

What does the commutator do in DC motors?

• A. Reverses current direction to maintain rotational motion
• B. Generates a magnetic field
• C. Stores energy
• D. Insulates windings

Answer: (A)

The commutator keeps the motor turning by reversing the current in the armature windings as the rotor passes through positions where the torque would naturally reverse. As the coil moves in the magnetic field, the direction of the force on the current would change if the wiring stayed the same, causing the rotor to stall or oscillate. The commutator, a split ring connected to the winding and working with stationary brushes, swaps the winding’s connections every half turn so the magnetic forces continue producing torque in the same rotational direction. In short, it converts the alternating effect of rotation into continuous, unidirectional torque. It isn’t generating the magnetic field (that's the field magnets or field windings), nor is it storing energy (that’s handled by other components like a flywheel or capacitors), and it isn’t primarily insulating windings.

The commutator keeps the motor turning by reversing the current in the armature windings as the rotor passes through positions where the torque would naturally reverse. As the coil moves in the magnetic field, the direction of the force on the current would change if the wiring stayed the same, causing the rotor to stall or oscillate. The commutator, a split ring connected to the winding and working with stationary brushes, swaps the winding’s connections every half turn so the magnetic forces continue producing torque in the same rotational direction. In short, it converts the alternating effect of rotation into continuous, unidirectional torque.

It isn’t generating the magnetic field (that's the field magnets or field windings), nor is it storing energy (that’s handled by other components like a flywheel or capacitors), and it isn’t primarily insulating windings.