Reed Switch consists of an elastic reed of magnetic material, which is sealed in a glass tube filled with inert gas. The end faces of the magnetic sheets overlap but there is a certain gap in the middle, and the end face contacts are plated with a layer of precious metals (such as rhodium, ruthenium, etc.). Increases the stability of the switch and extends the service life of the machine.

When a magnet or electromagnetic coil generates a magnetic field that acts on the switch, both reeds of the Reed Switch are magnetized. An N pole is generated at the contact point of one of the reeds, and an S pole is generated at the contact point of the other reed. If the attractive force generated by the magnetic field overcomes the resistance generated by the elasticity of the reed, the reed will contact and conduct due to the attractive force, that is, the circuit is closed. Once the magnetic field weakens to a certain extent, the reeds will separate again due to elastic force, that is, the circuit will be disconnected. /