Electric tool motors can be divided into DC motors and AC motors due to different input currents. The principles are as follows:
(1) DC motor-a motor that uses DC current to rotate is called a DC motor. Because of the different ways of connecting the magnetic field circuit and the armature circuit, they can be divided into series motors, split motors, and double-excited motors;
(2) AC motor-the induction motor in AC motor, its strong induced current (eddy current) is generated in the rotating magnetic field. The copper rod on the rotor cuts the magnetic field lines continuously. According to Lenz's law, this induced current has an anti-magnetic field. The effect of relative movement with the rotor, so the rotor rotates with the magnetic field. However, the rotating speed of the rotor is not as high as that of the magnetic field transformation, otherwise the magnetic lines of force will not be cut by the copper rod. A motor that uses alternating current to rotate is called an alternating current motor. There are many types, mainly:
Rectifier motor-the series-excited DC generator is used as an AC motor to form this kind of motor. Because the alternating current is in the magnetic field and the armature circuit while turning, the direction of the couple torque remains unchanged, and the machine does not rotate. stop. This kind of motor is also called "universal motor" because it can use both AC and DC. Vacuum cleaners, sewing machines and other household appliances often use this type of motor.
