Analysis of Automotive Control Relay Technology

The car control relay has two main parts, one is the control system and the other is the controlled system. The reason why the control relay can control is because when a certain signal is input into its control system, such as electric, magnetic, thermal, optical and other physical quantities reach a certain value, the controlled system (also called the output circuit) can be The amount of control is abruptly changed from zero to a fixed value, or a certain value is abruptly changed to zero, thereby achieving control, protection, transmission, and conversion of information. Controlling large currents with small currents is a feature of controlling relays.

Automotive control relay technology is demanding because it is suitable for vibration, high temperature, low temperature, humidity, and harsh environments such as oil, salt, water, etc. It requires long life, high reliability, small size, low consumption, and electromagnetic compatibility and resistance. Flammability, fast response and other properties. It can be said that as a horse to run, but also the horse does not eat grass. As an automotive control relay, it must meet these requirements.

Take the commonly used car lighting control relay as an example, there are mainly three-foot, four-leg and five-leg type control relays. Separately control the headlights, front small lights and instrument lights, corner lights, rear lights, brake lights, reverse lights, fog lights, car lighting and so on. When the combination switch is turned to the headlights ON position, the control system of the headlight relay (the field coil part) is energized to generate a magnetic field, and the alloy contacts are immediately closed, and the current of the control system is turned on, thereby controlling the opening of the headlights. When the combination switch is turned to the headlights OFF position to disconnect the power supply, the magnetic field disappears and the control alloy contacts are immediately separated, the current of the controlled system is cut off, and the headlights are turned off.

The current automotive control relays are still mechanical, but they are moving toward solid state relays. The key to the relay is reliability, because once the relay fails, it will immediately cause the function of the system components, and even cause the entire car to move. For example, if the starter relay fails, the car cannot be electrically started. Although the starter relay has a maximum of ten dollars, it is inconvenient to run without it.

There are two main types of domestic car control relays according to the classification of the vehicles in use. One is the imitation of European car relays, mainly for the introduction of technical vehicles in Germany and France, and the other is the imitation of Japanese car relays, mainly for Japanese models.