Motor (English: Electricmachinery, commonly known as "motor") refers to an electromagnetic device that realizes the conversion or transmission of electric energy according to the law of electromagnetic induction.

The motor is represented by the letter M (the old standard is D) in the circuit, and its main function is to generate driving torque as a power source for electrical appliances or various machinery. The generator is represented by the letter G in the circuit, and its main function is to convert mechanical energy into electrical energy.

1. According to the type of working power supply: it can be divided into DC motor and AC motor.

1) DC motors can be divided according to their structure and working principle: brushless DC motors and brushed DC motors.

2) AC motors can also be divided into: single-phase motors and three-phase motors.

2. It can be divided according to the structure and working principle: it can be divided into DC motor, asynchronous motor and synchronous motor. 

1) Synchronous motors can be divided into: permanent magnet synchronous motors, reluctance synchronous motors and hysteresis synchronous motors.

2) Asynchronous motors can be divided into: induction motors and AC commutator motors.

3. According to the starting and running mode, it can be divided into: capacitor starting single-phase asynchronous motor, capacitor running single-phase asynchronous motor, capacitor starting running single-phase asynchronous motor and split-phase single-phase asynchronous motor.

4. According to the application, it can be divided into : driving motor and control motor.

1) Driving motors can be divided into: electric tools (including drilling, polishing, polishing, slotting, cutting, reaming and other tools); home appliances (including washing machines, electric fans, refrigerators, air conditioners, tape recorders, video recorders, DVDs, etc.) Machines, vacuum cleaners, cameras, hair dryers, electric shavers, etc.); motors for other general-purpose small mechanical equipment (including various small machine tools, small machinery, medical equipment, electronic instruments, etc.).

2) The control motor is divided into: stepping motor and servo motor, etc.

5. According to the structure of the rotor, it can be divided into : cage induction motor (the old standard is called squirrel cage asynchronous motor) and wound rotor induction motor (the old standard is called wound asynchronous motor).

6. According to the operating speed, it can be divided into high-speed motors, low-speed motors, constant-speed motors, and speed-regulating motors. Low-speed motors are further divided into gear reduction motors, electromagnetic reduction motors, torque motors and claw pole synchronous motors.

DC motors are motors that operate on DC operating voltage and are widely used in radio cassette recorders, video recorders, DVD players, electric shavers, hair dryers, electronic watches, toys, etc.

In the case that the power supply line is not very long, the relationship between power and wire diameter (national standard copper wire)