Home > News > Industry News

How the motor works?


How the starter works
The control device of an automobile starter includes an electromagnetic switch, a starter relay and an ignition starter switch lamp component, wherein the electromagnetic switch is made together with the starter.
一. Electromagnetic switch
1. Structural characteristics of electromagnetic switch
The electromagnetic switch is mainly composed of two parts: the electromagnet mechanism and the motor switch. The electromagnet mechanism consists of a fixed iron core, a movable iron core, an attracting coil and a holding coil. The fixed iron core is fixed, and the movable iron core can move axially in the copper sleeve. A push rod is fixed at the front end of the movable iron core, a switch contact plate is installed at the front end of the push rod, and the rear section of the movable iron core is connected with the fork by adjusting screws and connecting pins. A reset spring is installed on the outside of the copper sleeve, and the function is to reset the movable parts such as the movable iron core.
2. Working principle of electromagnetic switch
When the magnetic flux generated by the attracting coil and the keeping coil energized is in the same direction, the electromagnetic attraction force is superimposed on each other, which can attract the movable iron core to move forward until the contact plate at the front end of the push rod turns on the electric switch contact and the main circuit of the motor is connected. .
When the magnetic fluxes generated by the attracting coil and the holding coil are in opposite directions, their electromagnetic attraction forces cancel each other out. Under the action of the return spring, the movable parts such as the movable iron core are automatically reset, the contact disc and the contact are disconnected, and the main circuit of the motor is disconnected. .

二. Starter relay

The structure diagram of the starter relay consists of an electromagnet mechanism and a contact assembly. The coil is respectively connected with the ignition switch terminal and the ground terminal "E" on the housing, the fixed contact is connected with the starter terminal "S", and the movable contact is connected with the battery terminal "BAT" through the contact arm and the bracket. The starter relay contacts are normally open contacts. When the coil is energized, the relay core will generate electromagnetic force to close the contacts, thereby connecting the attracting coil and holding coil circuits controlled by the relay.
1. Control circuit
The control circuit includes a starter relay control circuit and a starter electromagnetic switch control circuit.
The starting 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, the current flows from the positive pole of the battery through the starter power terminal to the ammeter, and from the ammeter through the ignition switch, the relay coil returns to the negative pole of the battery. So the iron core of the relay generates a strong electromagnetic attraction force, the contact of the relay is closed, and the control circuit of the electromagnetic switch of the starter is turned on.
2. Main circuit

Battery positive → starter power terminal → electromagnetic switch → excitation winding → armature winding → ground → battery negative, so the starter generates electromagnetic torque and starts the engine