One of electromagnetic relays and solid-state relays is afraid of shocks, the other is not afraid of shocks; the former is afraid of magnetism and the latter is afraid of induced electricity; one has low heat and the other has high heat; one is low in price and the other is high in price; the former is easy to replace and the latter is the opposite.

The structure and working principle of electromagnetic relay is similar to that of contactor, which is mainly composed of electromagnetic mechanism and contacts. There are also two types of electromagnetic relays, DC and AC. The suction value and release value of the relay can be adjusted within a certain range according to the protection requirements. Now the DC electromagnetic relay shown is used as an example to illustrate.

What is the function of the relay coil? We should all know the function of the relay. As long as a certain voltage is applied to both ends of the coil, a certain current will flow through the coil, resulting in an electromagnetic effect, and the armature will be attracted by the electromagnetic force. Under the action, it overcomes the pulling force of the return spring and attracts to the iron core, thereby driving the movable contact of the armature and the static contact (normally open contact) to attract. The function of the coil is to make the upper coil charged by the input voltage to adsorb or pop the relevant contact points, so as to realize the function of mechanically opening/breaking another set of circuits, so as to achieve the desired output. Therefore, the coil is the main component of the relay. To convert electrical energy into mechanical energy to achieve control.