The various types of direct current electric motors are individualized by the stator construction or even by the way the magnetic bearings are connected to the power supply. These bearings are connected to separate bearings of the rotor, in this way, a dynamic magnetic field is sprouted inside the motor at the instant at which a voltage is concentrated between the brushes of the motor.
Unlike other categories of electric motors, only DC motors do not need a controller so that you can alternate current in the motor bearings. Thus, the switching of the windings of a DC motor is done mechanically. It has a switch on the shaft of this motor, so as the motor rotates, the carbon brushes act on the switch, getting in touch with different segments of the device.
As the motor rotates, its bearings are energized intermittently in a sequence, so that the magnetic poles generated by the rotor can not overcome the poles caused in the stator. This field change in rotor bearings is called commutation. The stator is responsible for forming a stationary magnetic field that surrounds the rotor. This field appears due to the operation of permanent magnets and electromagnetic coils.