Brushless DC motor is difficult to match in variable speed applications because of its unique performance and simple control. Although AC motor and control have recently developed to compete with many of its advantages, brush DC motor is still common in many industries, especially in mechanical equipment, automotive electronics, home intelligence, automatic doors and windows and so on.

The working principle of DC motor is that the wire carrying current will be subjected to physical force when passing through the magnetic field. This magnetic field is usually generated in the stationary part of the motor. It applies a force to the winding wire connected to the rotating part of the motor, which is connected to the output shaft. By switching the magnetic direction according to the rotor position, the rotor armature is alternately pulled in one direction and then pushed in the opposite direction to produce continuous rotational motion. This process is called commutation.

The key difference between DC and AC motors is that DC motors require specific commutator devices to operate. In contrast, AC motors use the AC of the input power supply to drive the switching effect.

In the brush DC reduction motor, the commutator has a conductive brush, which presses on the rotor and contacts different parts of the armature according to the rotor position, which effectively uses the rotor as a switch to change the direction of the electromagnetic field. Brushless DC motors use Hall effect sensors to identify rotor position and manage commutation, so that there is no need for electrical contact with the rotor.