Patent ID: 6412347
Filing Date: 2002-07-02
Classification: G01C

Abstract:
An angular rate sensor comprising:an exciting unit for providing a vibrator with vibration; a means for detecting a vibration level of said vibrator; a detection means for detecting Coriolis' force generated responsive to an angular rate; a first amplifier for amplifying an output signal of said means of detecting vibration level; a rectifier circuit for rectifying an output signal of said first amplifier to obtain a DC voltage; a variable gain amplifier for taking as an input the output signal of said first amplifier, wherein an amplification factor varies according to an output voltage of said rectifier circuit; a second amplifier for amplifying an output signal of said variable gain amplifier; a level judgement circuit for generating an output corresponding to a level of the output voltage of said rectifier circuit; and a third amplifier and a switch placed between said first amplifier and said second amplifier, wherein the output signal of said first amplifier is input to a positive input terminal of said third amplifier; a first resistor is inserted between a negative input terminal of said third amplifier and an output terminal of said third amplifier; a voltage having a potential in the vicinity of Â½ of a power supply voltage is impressed upon the negative input terminal of said third amplifier through a capacitor; a second resistor and said switch means are connected in series between the output terminal of said third amplifier and an input terminal of said second amplifier; and said switch means is activated by said output of said level judgement circuit.