Research on the Principle of New Type Sensor Detection Circuit

摘要

The capacitive sensor is a conversion device that uses a capacitor as a sensing element to convert the physical quantity into a variable capacitance. This paper introduces five kinds of detection circuit used capacitive sensor: operational amplification method, pulse width modulation method, transimpedance amplification detection method, charge transfer method and AC bridge capacitance detection method. The basic principle of the detection circuits is introduced. The advantages and disadvantages of different methods are compared in terms of stability, sensitivity and anti-stray capacitance for different applications. This paper provides reference for designing detection circuit by using capacitive sensors.