What is the difference between a solid state relay and a normal relay

Update:11-05-2019
Summary:

The comparison between traditional relays and solid sta […]

The comparison between traditional relays and solid state relays, due to the variety of types involved, the following comparison of electromagnetic relays with the corresponding solid state relays to illustrate their differences:
      1. Structural difference: The electromagnetic relay works by the suction circuit generated between the electromagnet core and the armature in the circuit of the input circuit; the electronic component of the solid relay fulfills its function without mechanical moving parts, and the input and output are isolated.
      2, the difference of working methods: electromagnetic relay is the principle of electromagnetic induction, through the power of the electromagnet to control the circuit on and off, therefore, with DC power coil, contacts can be through, direct current; solid state relays rely on semiconductor devices and electronic components Electrical, magnetic and optical characteristics to complete its isolation and relay switching functions, therefore, divided into DC input - AC output type, DC input - tributary output type, AC input - AC output type, AC input - DC output type.
      3. Difference in working status: The electromagnetic relay uses the suction force generated between the armatures to open and close the circuit. Therefore, the action response is slow, noisy, and the life is limited; the solid state relay has fast response, no noise operation and long service life.
      4, the use of the environment: temperature, humidity, atmospheric pressure (altitude), sand pollution, chemical gases and electromagnetic interference and other factors, electromagnetic relays are generally inferior to solid state relays.
      5, electrical performance difference: electromagnetic relay and the corresponding solid state relay, the former is simple to drive, but the power consumption is large, isolation is good, short-term overload tolerance is good, control large current, high power occasions are not as good as the latter, control actions are numerous When the circuit is used, the life is not as long as the latter.

More Information: smart home relay