Variable area inductive sensor, also known as cylindrical inductive displacement sensor, is mainly used in machine tools, automation equipment and other industrial fields, and can accurately measure non-contact distance. The basic structure of the sensor consists of a main body, an iron core and a coil. The iron core is installed in the center of the sensor main body and nested with the coil. When the external force is input, the cross-sectional area of the iron core will change, thus changing the inductance in the coil.
The sensor circuit is mainly composed of a regulated power supply, an AC power supply, an amplifier and a sampling circuit. The regulated power supply provides a stable working voltage for the whole circuit, and the AC power supply provides an excitation signal for the sensor. The amplifier and sampling circuit are used to amplify and collect the signal output by the sensor. The measurement accuracy of the whole circuit depends on the design of coil and iron core, as well as the accuracy and noise control of the circuit.