The relay is composed of an iron core, a coil, an armature, a contact spring, etc. When 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 armature will overcome the pulling force of the return spring under the action of electromagnetic attraction and be attracted to the iron core, thereby driving the moving contact of the armature and the static contact (normally open contact) to attract. When the coil is powered off, the electromagnetic attraction 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) are released. In this way, the attraction and release achieve the purpose of conduction and disconnection in the circuit. For the "normally open and normally closed" contacts of the relay, they can be distinguished as follows: the static contact in the disconnected state when the relay coil is not powered is called the "normally open contact"; the static contact in the connected state is called the "normally closed contact". Relays generally have two circuits, a low-voltage control circuit and a high-voltage working circuit.
1. When there is a high-level signal at the signal input end, the common end and the normally open end will be connected.
2. Can directly control various devices and loads.
3. With the power supply and relay action indication, it lights up when it is closed and does not 4. light up when it is disconnected.
5. There is a normally open and a normally closed contact.
6. Control DC or AC signals, and can control 220V AC loads.
