An inductive sensor is a non-contact sensor designed to control the position of metal objects (not sensitive to other materials).
The principle of operation is based on a change in the oscillation amplitude of the generator when a metal, magnetic, ferromagnetic or amorphous material of a certain size is introduced into the active zone of the sensor. When power is applied to the limit switch, a changing magnetic field is formed in the area of its sensitive surface, which induces eddy currents in the material introduced into the zone, which lead to a change in the oscillation amplitude of the generator. As a result, an analog output signal is generated, the value of which varies with the distance between the sensor and the controlled object. The Schmitt trigger converts an analog signal to a logic signal.
Inductive sensors are widely used to solve the problems of process control systems. They are carried out with a normally open or normally closed contact.