Solid state relay

Solid state relay (SOLIDSTATERELAYS, The following abbreviation is “SSR”), It is a new contactless switching device composed entirely of solid-state electronic components , It uses electronic components ( Such as switching triode 、 Semiconductor devices such as bidirectional thyristor ) Switching characteristics of , It can connect and disconnect the circuit without contact and spark , So it's also called “ Contactless switch ”. Solid state relay is a four terminal active device , Two terminals are input control terminals , In addition, both ends are output controlled ends . It has both amplification and driving effect , It also has the function of isolation , It is very suitable for driving high-power switch actuator , It is more reliable than electromagnetic relay , Without contact 、 Long life 、 Fast , The interference to the outside world is also small , It has been widely used .

Solid state relays are encapsulated by equivalent circuits of various semiconductors or conductors , Therefore, physical closing operation of entity nature will not be generated in the working process , This kind of relay effectively avoids the generation of electric sparks and strong electromagnetic interference , The closing frequency of this kind of relay is also high , Therefore, it is very suitable for some working conditions with high switching frequency and low interference , However, the inconvenience in maintenance and inspection should also be fully considered when using , Of course , Reliable relay products , Generally, it is only used according to the rated parameters , It is also rare to have unstable or unsafe work .
Because of its physical principle , Its electromagnetic radiation amount and range are smaller than the relay types of physical closing , It can be applied to a wider range , Some working conditions with less stringent requirements for interference sources or higher requirements for frequency can be selected .