An optocoupler is an electronic component that transmits electrical signals through light. It consists of a light emitter and a light receiver, which are isolated from each other yet capable of signal transmission. While transmitting signals, it can achieve electrical isolation between input and output circuits, avoiding electrical interference and high-voltage breakdown. Additionally, it can perform signal amplification or switch control. It has a wide range of applications: in switching power supplies and charging piles, it isolates high and low voltages to ensure safety; in industrial control (such as PLC and motor drives), it prevents interference to maintain accuracy; in home appliances and automotive electronics, it isolates sensitive circuits from strong electricity to improve stability.