Unlike other motor types (ie, brushless DC motors and AC induction motors), BDC motors do not require a controller to switch the direction of the current in the electrode windings, but mechanically complete the commutation of the BDC motor windings.
A split copper sleeve is installed on the shaft of the BDC motor, which is called a commutator. As the motor rotates, the carbon brushes slide along the commutator and contact different segments of the commutator. These segments are connected to different rotor windings, so when power is applied through the brushes of the motor, a dynamic magnetic field is generated inside the motor. It is important to note that the brush and the commutator are the most easily lost parts of the BDC motor due to relative sliding between the two.