Patent ID: 8621924
Filing Date: 2014-01-07
Classification: G01N

Abstract:
1. A humidity sensing circuit with temperature compensation, comprising: a wave producing module, capable of outputting a wave signal, wherein the wave producing module comprises: an operation amplifier; a first resistor having one end for receiving a power signal and the other end electrically connected with a positive input terminal of the operation amplifier; a second resistor having one end electrically connected with the positive input terminal of the operation amplifier and the other end grounded; a third resistor having one end electrically connected with a negative input terminal of the operation amplifier and the other end connected with an output terminal of the operation amplifier; a fourth resistor having one end electrically connected with the positive input terminal of the operation amplifier and the other end connected with the output terminal of the operation amplifier; and a capacitor having one end electrically connected with a negative input terminal of the operation amplifier and the other end grounded; a phase processing module, capable of receiving the wave signal and outputting an oscillatory wave and an invert oscillatory wave according to the wave signal; a sensing module having a temperature sensor and a humidity sensor connected in series, wherein the temperature sensor and the humidity sensor respectively receive the oscillatory wave and the invert oscillatory wave, and the sensing module is capable of outputting a parameter signal according to the oscillatory wave and the invert oscillatory wave; and a detecting module, capable of outputting a detection signal according to the parameter signal.