What is the working principle of a brushed DC motor.

What is the working principle of a brushed DC motor.

Brushed DC motors are difficult to match in variable speed applications due to their unique performance and simple control. Although AC motors and controls have recently developed to compete with many of their advantages, brushed DC motors are still widely present in many industries, especially in mechanical equipment, automotive electronics, home intelligence, automatic doors and windows, which require compact, efficient, and responsive motors.

The working principle of a DC motor is that the wire carrying current will experience physical forces when passing through a 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, producing continuous rotational motion. This process is called commutation.

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

In a brushed DC deceleration motor, the commutator has a conductive brush that presses against the rotor and contacts different parts of the armature according to the rotor position, effectively using 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, eliminating the need for electrical contact with the rotor.