What is the function of automobile motor relay?

Automobile motor relay mainly controls the current of high voltage line by controlling the current of low voltage line, and plays the role of current switch. The starting relay is one of the components of the starting system. Its main function in automobiles is to control the motor to rotate through small current and large current, so as to drive the magneto rotor inside the generator to rotate, and input the ignition pulse signal to the igniter, so that the igniter can generate electric spark to ignite the mixture in the cylinder to do work.

The working principle of electromagnetic relay is very simple. It uses the principle of electromagnetic induction. When DC passes through the coil, the coil generates a magnetic field, and the moving iron is attracted to drive the contact reed, so that the static contact is separated and the moving contact is closed. When the current of the electromagnetic coil is cut off, the core loses magnetism, and the moving core is reset under the action of spring force, and the moving contact is opened and the static contact is closed.

Extended data:

Relay is an automatic switching element with isolation function, which is widely used in remote control, telemetry, communication, automatic control, mechatronics and power electronic equipment, and is one of the most important control elements.

Relays generally have an induction mechanism (input part), which can reflect some input variables (such as current, voltage, power, impedance, frequency, temperature, pressure, speed, light and so on). ); There is an actuator (output part) which can control the on-off of the controlled circuit; Between the input part and the output part of the relay, there is also an intermediate mechanism (driving part) for coupling and isolating the input quantity, processing the function and driving the output part.

References:

Baidu encyclopedia-relay