Solid State Relays

Solid-state relays (SSRs) are optically isolated electronic switching devices that switch on or off when a small voltage is applied across control input terminals. SSRs are similar to chassis, DIN rail, socket and board mount electromechanical relays designed to switch either AC or DC loads up to 660 volts but are semiconductor based and have no moving parts. They are selected by load voltage, current ratings, and switch circuit configurations such as SPST, SPDT, DPST and 3PST.