Power Relays

Heavy-duty power relay, which works with solenoid action is shown in Fig. 6-20. In this device, the spring pulls the electromagnetic core, or anchor, away from electrical contact when the current off. When current flows, valves pulled to a coil. Electric contact is connected to the valve is closed or opened with the help of this operation. Please note that electromagnetism can be used for opening or closing of the relay. The further actions depend on the design of the relay. Relay contacts can be arranged various functions, such as SPST, SPDT, DPDT, or any other combination.

Advantage relay is that the significant traction can be developed with a small current coil. Contacts can be quite large and can handle or sensor high values of electric power. Very small amount of control the power, thus, can be used to change much higher voltages and currents in a safe manner (see Fig. 6-21).

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