The control device of the automobile starter includes an electromagnetic switch, a starting relay and an ignition starter switch lamp part, in which the electromagnetic switch and the starter are made together.

1. Electromagnetic switch P/>1. Structural characteristics of electromagnetic switch

The solenoid switch is mainly composed of two parts: the solenoid mechanism and the motor switch. The electromagnet mechanism is composed of a fixed core, a movable core, a suction coil and a holding coil. The fixed core is fixed, and the movable core can be moved axially in the copper sleeve. The front end of the movable iron core is fixed with the push rod, and the front end of the push rod is provided with a switch contact plate, and the rear section of the movable iron core is connected with the fork with an adjusting screw and a connecting pin. A return spring is installed on the outside of the copper sleeve, and the function is to reset the movable parts such as the movable core. The arrangement of the terminals of the solenoid switch wiring is shown in the figure

2. The working principle of electromagnetic switch

When the magnetic flux generated by the suction coil and the coil energized are in the same direction, their electromagnetic attraction is superimposed on each other, and the movable core can be attracted to move forward until the contact plate at the front end of the actuator connects the electric switch contact to the main circuit of the potential motor.

When the magnetic pain generated by the suction coil and the holding coil energized are in opposite directions, their electromagnetic attraction cancels each other, and under the action of the return spring, the movable parts such as the movable core are automatically reset, the contact plate is disconnected from the contact, and the main circuit of the motor is disconnected.

Second, the starting relay

The structure of the starter relay is shown in the upper left corner of the figure, which is composed of an electromagnet mechanism and a contact assembly. The coil is connected to the ignition switch terminal and the lap iron terminal "E" on the housing, the fixed contact is connected to the starter terminal "S", and the movable contact is connected to the battery terminal "BAT" through the contact arm and bracket. When the coil is energized, the relay core generates electromagnetic force to close the contact, so that the suction coil and the holding coil circuit controlled by the relay are connected.

1. Control circuits

The control circuit includes a starter relay control circuit and a starter electromagnetic switch control circuit.

The starter relay control circuit is controlled by the ignition switch, and the controlled object is the relay coil circuit. When the ignition switch is turned on and the starting gear is turned on, the current passes from the battery through the starter power supply post to the ammeter, and the relay coil returns to the negative pole of the battery through the ignition switch from the ammeter. Therefore, the relay core produces a strong electromagnetic attraction, which is the control circuit of the relay contact closure and the starter electromagnetic switch.

2. Main circuit

After the electromagnetic switch is turned on, the suction coil 3 and the holding coil 4 generate a strong electromagnetic attraction force, and the main circuit of the starter is turned on. The circuit is:
The positive pole of the battery → the power binding post of the starter→ the electromagnetic switch→ the excitation winding resistance → the armature winding resistance→ the iron → the negative electrode of the battery, so the starter generates an electromagnetic rotation distance and starts the engine.