What are the reversal methods of DC motors

A DC motor is a motor that converts DC electrical energy into mechanical energy. It is widely used in resistors because of its good speed regulation performance. According to the excitation mode, DC motors are divided into three categories: permanent magnet, separately excited and self-excited, of which self-excitation is further divided into three types: shunt excitation, series excitation and compound excitation. Let me introduce to you "what are the methods of reversing a DC motor".

1. Armature reverse connection method

The polarity of the voltage at the end of the field coil remains unchanged, and the motor rotates by changing the polarity of the voltage at the end of the armature coil.

2. Excitation rotation is reverse connection method

Keep the voltage polarity at the armature coil terminal unchanged, and adjust the motor direction by changing the voltage polarity at the excitation coil terminal. If the polarities of the two voltages are changed at the same time, the direction of rotation of the motor will not change.

3. Change the brush access position of the armature

Change the bias angle of the armature winding and the field winding to change the orientation of the DC motor.

In addition, the forward and reverse windings of separately-excited and shunt-excited DC motors usually adopt the armature reverse connection method. Separately excited and parallel DC motors do not use the reverse connection of the excitation coil to realize the forward and reverse rotation, because the number of turns of the excitation coil is large, when the excitation winding is reversely connected, a large induced electromotive force will be generated in the excitation winding. This can damage the blade and field winding insulation.