How does a solid state relay work?

Solid-state relays use light-emitting diodes and light-sensitive semiconductors to turn on and off outgoing power. Usually, a lower voltage switching circuit controls a higher voltage output. Solid-state relays are used in a variety of industrial switches where a simple mechanical switch cannot handle the current. read more

Solid-state relays have fast switching speeds compared with electromechanical relays, and have no physical contacts to wear out. Application of solid-state relays must consider their lower ability to withstand momentary overload, compared with electromechanical contacts, and their higher "on" state resistance. read more

A solid state relay (SSR) is an electronic device to switch the electrical current, rather than an electromechanical device. read more