Research on Passive Proximity Sensor based on Field-Circuit Combination Method

Abstract

Proximity sensor is a kind of sensor that detects the proximity of objects. When a ferromagnetic object passes through its sensing range at a certain speed, the magnetic field distribution of the sensor will be affected, and an output voltage signal will be generated according to the Faraday Electromagnetic Induction Principle. There are great differences in the shape and size of proximity sensors in different application fields. The general design approach is to fine tune the parameters according to the actual application scenarios according to commonsense. In this paper, the field-circuit combination method is used to systematically study the proximity sensor. Through the combination of the two methods, the sensor structure scheme is studied, and the design method relying solely on experience is improved; The quantitative calculation is carried out from the perspective of magnetic field, which solves the problem that it is difficult to theoretically calculate the magnetic circuit parameters when the yoke shape is irregular. According to the design model, the prototype and simple experimental devices are made, and the theoretical analysis is verified by experiments.