What Are the Differences Between Different Types of Relays?

thermal relay

Thermal relay is a relay that uses the thermal effect generated by the current flowing through the relay to make corresponding actions. The delayed action time of the thermal relay shortens as the passing current increases. It is mainly used for motor protection and control of the heating status of other equipment.

Time Relay

A time relay is a relay that has a required delay time from receiving the action signal to the contact action. Mainly used in time-sequential control circuits. Commonly used time relays mainly include electromagnetic type, electric type, air damping type and transistor type.

solid state relay

Solid state relay is a relay composed of semiconductor devices and is a contactless electronic switch. It has the advantages of reliable operation, long life, switching speed and so on. However, solid-state relays generally generate large amounts of heat and require special heat sinks.

Intermediate relay

Intermediate relays are relays used to increase the number of signals in a control circuit or to amplify signals. The structure and working principle are basically the same as those of contactors. In circuits where the operating current is less than the relay contact current, the intermediate relay can be used instead of the contactor.

Current relay

A current relay is a relay whose coils are connected in series in the circuit under test and act according to changes in the current value. It is divided into two types: overcurrent relay and undercurrent relay. Generally used is the overcurrent relay.

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