Solid State RelaysA solid state relay (SSR) is a type of electrical relay that uses a solid-state electronic switching device, such as a transistor or thyristor, instead of a mechanical switch to open and close the relay contacts. Unlike a regular electromechanical relay, which uses an electromagnet to move the contacts, an SSR has no moving parts, which makes it faster, more reliable, and more durable than a mechanical relay. Solid state relays are commonly used in a wide variety of applications, including automation, industrial control, and power electronics. They can be used to control high-power loads, such as motors, heaters, and lights, and may also include additional features such as overcurrent protection, current sensing, and PWM control.