What does the automobile main relay do? There are many motors in the car.

Main relay generally refers to the main power relay of the engine control unit, which provides power for the engine control unit. Some vehicles have a delay function. After the ignition switch is turned off, the power supply is delayed for a few seconds, so that the throttle and other electrical appliances can return to the initial position.

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.

As a control element, to sum up, the relay has the following functions:

1) expand the control range. For example, when the control signal of multi-contact relay reaches a certain value, multiple circuits can be switched, disconnected and connected at the same time according to different forms of contact groups.

2) zoom in. Such as sensitive relays, intermediate relays, etc. With a small amount of control, you can control a high-power circuit.

3) Integrated signal. For example, when a plurality of control signals are input into a multi-winding relay in a specified form, a predetermined control effect is achieved through comparison and synthesis.

4) Automatic and remote control and monitoring. For example, the relay on the automatic device can form a program control circuit together with other electrical appliances, so as to realize automatic operation.