What's the function of relays?

What's the function of relays?

Relays generally have induction mechanisms that reflect certain input variables (such as current, voltage, power, impedance, frequency, temperature, pressure, speed, light, etc.).It has an executive mechanism that can realize "on" and "off" control of the controlled circuit;Between the input part and the output part of the relay, there are intermediate mechanisms for coupling isolation of the input, functional processing and driving of the output part.

As long as a certain voltage is applied to both ends of the coil, a certain current will flow through the coil, resulting in electromagnetic effect. The armature will overcome the pull of the returning spring and pull toward the core under the action of electromagnetic force, thus driving the moving contact of the armature to pull in the static contact (normally open contact).When the coil is cut off, the electromagnetic suction also disappears, and the armature returns to its original position in the reaction force of the spring to make the moving contact and the original static contact (normally closed contact) snap together.Such suction, release, thus achieved in the circuit conduction, cut off the purpose.