The control device of the automobile starter includes an electromagnetic switch, a starting relay and an ignition starting switch lamp part, wherein the electromagnetic switch is made together with the starter.

First, the electromagnetic switch p /> 1. Electromagnetic switch structure

Electromagnetic switch mainly by the electromagnet mechanism and the motor switch in two parts. The electromagnet mechanism consists of a fixed iron core, an active iron core, an attraction coil and a holding coil. Fixed iron core fixed, movable core in the copper sleeve to do axial movement. The front end of the movable iron core is fixed with a push rod, the front end of the push rod is provided with a switch contact plate, and the rear end of the movable core is connected with a shift fork by an adjusting screw and a connecting pin. Outside the copper sleeve is fitted with a return spring, the role is to move the movable core components such as reset. The positions of the terminals of the electromagnetic switch wiring are shown in the figure

2. Electromagnetic switch works

When the suction coil and keep the magnetic flux generated by the same coil, the electromagnetic attraction to each other, can attract the active core forward, until the front end of the push rod touch the electrical switch contacts connected to the main motor circuit .

When the attracting coil and keep the coil magnetic pain generated by the opposite direction, the electromagnetic attraction cancel each other, under the action of the return spring, movable core and other movable parts automatically reset, contact and contact disconnect, the motor main circuit .

Second, start the relay

Starting relay structure diagram shown in the upper left part of the figure, by the electromagnet mechanism and contact assembly. The coil is connected with the ignition switch terminal and the ground terminal "E" of the housing respectively, and the fixed contact is connected with the starter terminal "S", and the movable contact is connected with the battery terminal "BAT" via the contact arm and the bracket. When the coil is energized, the relay core will generate electromagnetic force to close the contact, so that the relay-controlled attracting coil and the holding coil circuit are connected to the starting relay.

1. Control circuit

The control circuit comprises a starting relay control circuit and a starter electromagnetic switch control circuit.

Starting relay control circuit is controlled by the ignition switch, the object is controlled by the relay coil circuit. When the ignition switch starting gear, the current from the battery through the starter power supply terminal to the ammeter, from the ammeter through the ignition switch, the relay coil back to the battery negative. Then the relay core to produce a strong electromagnetic attraction, is the relay contact closure, connected to the starter electromagnetic switch control circuit.

2. The main circuit

When the electromagnetic switch is turned on, the attracting coil 3 and the holding coil 4 generate strong electromagnetic attraction, and the starter main circuit is turned on. The circuit is:

Battery positive → starter power supply terminal → electromagnetic switch → excitation winding → armature winding → ground → battery negative, so the starter produces electromagnetic torque, start the engine.