Editing Relay (section)

=== Solid-state relay ===
[[File:Solid state relay.jpg|thumb|[[Solid state (electronics)|Solid-state]] relays have no moving parts.]]
[[File:Solid-state-contactor.jpg|thumb|25&nbsp;A and 40&nbsp;A solid state contactors]]

A [[solid-state relay]] (SSR) is a [[solid state (electronics)|solid state]] electronic component that provides a function similar to an [[electromechanical]] relay but does not have any moving components, increasing long-term reliability. A solid-state relay uses a [[thyristor]], [[TRIAC]] or other solid-state switching device, activated by the control signal, to switch the controlled load, instead of a solenoid. An [[optocoupler]] (a [[light-emitting diode]] (LED) coupled with a [[photo transistor]]) can be used to isolate control and controlled circuits.<ref>{{Cite web|url=https://www.electronics-tutorials.ws/blog/optocoupler.html|title=Optocoupler Tutorial|date=16 September 2013 }}</ref>