The rated working voltage of the relay is the most important technical parameter of the relay. When using a relay, the working voltage of the circuit (that is, the circuit where the relay coil is located) should be considered first, and the rated working voltage of the relay should be equal to the working voltage of the circuit where it is located. Generally, the working voltage of the circuit is 0.86 of the rated working voltage of the relay.

Note that the voltage of the workpiece in the circuit must not exceed the rated working voltage of the relay, otherwise the relay coil will be easily burned. In addition, some integrated circuits, such as the NE555 circuit, can directly drive the relay to work, while some integrated circuits, such as the CMOS circuit, have a small output current and need to add a transistor amplifier circuit to drive the relay. Therefore, it should be considered that the output current of the transistor should be greater than The rated operating current of the relay.