The automotive industry is increasingly using relays. The more common relays are: starting relays for starting motors, horn relays, motor or generator circuit breaker relays, charging voltage and current adjustment relays, switching signal flashing relays, light brightness control relays and air conditioning control relays, sliding door automatic opening and closing control relays , Poland window lift control relay. The power supply in the car now mostly uses 12V, and the coil voltage is mostly designed to be 12V. Because it is powered by a battery, the voltage is unstable, and the environmental conditions are harsh, the suction voltage V≤60%VH (rated working voltage), and the coil Guo voltage is allowed to reach 1.5VH. The power consumption of the coil is relatively large, generally 1.6~2W, and the temperature rise is relatively high. The environmental requirements are quite harsh, the ambient temperature range is -40℃~100℃, the relay used in the engine box must be able to withstand the damage of sand, dust, water, salt, oil, vibration, shock is undoubtedly quite harsh, and the impact strength is 100G , Impact stability is up to 100G, vibration has 10~40HZ, double amplitude 1.27MM, 40~70HZ, 0.5G, 70~100HZ, 0.5MM (double amplitude), 100~500HZ, 10G and other levels.