The rated operating voltage of the relay is the most important technical parameter of the relay. When using a relay, you should first consider the working voltage of the circuit where it is located (that is, the circuit where the relay coil is located), 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 is easy to burn out.

Electromagnetic relays are generally composed of iron cores, coils, armatures, contact reeds, etc. As long as a certain voltage is applied to both ends of the coil, a certain current will flow through the coil, thereby generating an electromagnetic effect. The moving contact and the static contact (normally open contact) are sucked together. When the coil is de-energized, the electromagnetic suction will disappear, and the armature will return to its original position under the reaction force of the spring, so that the moving contact and the original static contact (normally closed contact) will be released.