A solid–state relay (SSR) is an electronic switching device that switches on or off when a small external voltage is applied across its control terminals.The relay may be designed to switch either AC or DC to the load. It serves the same function as an electromagnetically relay, but has no moving parts.
Relative advantages of solid state as against electromechanical relays.
Applications for Solid State Relays:
Solid state relays are ideal for repetitive applications due to the absence of moving parts. Some applications for solid state relays are: