Solid-state relay

A solid-state relay (SSR) is an electronic device that switches electrical power on or off without moving parts, using a small input signal to control a larger output circuit. It replaces traditional mechanical relays, providing faster operation, longer lifespan, and increased reliability. An SSR typically uses an opto-isolator to separate the control side from the power side, ensuring safety and preventing electrical noise from transferring between circuits. They are commonly used in automation and industrial applications where quick, silent switching and durability are important.