What are the differences between traditional relays and solid state relays?

Update:28-12-2019
Summary:

The comparison between traditional relays and solid-sta […]

The comparison between traditional relays and solid-state relays involves many types, so the following comparison between electromagnetic relays and corresponding solid-state relays illustrates their differences:

1. Structural difference: The electromagnetic relay works by using the suction force generated by the circuit in the input circuit between the electromagnet core and the armature; the solid relay uses electronic components to perform its function without mechanical moving components, and the input and output are isolated.

2. Differences in working methods: The electromagnetic relay uses the principle of electromagnetic induction to control the circuit on and off by the force of an electromagnet. Therefore, by using a direct current coil, the contacts can pass AC and DC current; solid state relays rely on semiconductor devices and electronic components Electrical, magnetic and optical characteristics to complete its isolation and relay switching functions, so it is 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 effect generated between the armature to open and close the circuit, so the action response is slow, noisy, and the life is limited; the solid state relay responds quickly, runs without noise, and has a long life.

4. Operating environment: In the influence of temperature, humidity, atmospheric pressure (altitude), sand and dust pollution, chemical gas and electromagnetic interference, electromagnetic relays are generally inferior to solid state relays.

5. Difference in electrical performance: Compared with the corresponding solid state relay, the former is simple to drive, but the power consumption is large, the isolation is good, and the short-term overload tolerance is good. In the circuit, the life is not as long as the latter.