Patent ID: 6345533
Filing Date: 2002-02-12
Classification: G01C

Abstract:
An angular rate sensor comprising:(a) a vibration exciter for providing a vibration body with vibrations; (b) means for detecting a level of vibrations of said vibration body with vibrations; (c) detecting means for detecting a Coriolis' force produced in proportion to an angular rate; (d) current amplifier circuit for amplifying an output signal of said means for detecting a level of vibrations; (e) a full-wave rectifier circuit for producing a D. C. voltage by rectifying an output signal of a first band-pass filter circuit, wherein an output signal of said current amplifier circuit is input; (f) an automatic gain control circuit whose amplification factor for the output signal of said first band-pass filter circuit varies according to a magnitude of an output signal of said full-wave rectifier circuit; (g) a driver circuit for driving said vibration exciter according to a magnitude of an output signal of said automatic gain control circuit; (h) a charge amplifier circuit for inputting and amplifying a signal detected by said detecting means for detecting a Coriolis' force; (i) a synchronous detection circuit for detecting an output signal of a second band-pass filter circuit, wherein an output signal of said charge amplifier circuit is input; (j) a sensor output terminal for outputting an output signal of a low-pass filter circuit, wherein an output signal of said synchronous detection circuit is input; (k) a reference voltage generator; and (l) a buffer provided between said reference voltage generator and a common terminal for said vibration exciter, said means for detecting a level of vibrations and said detecting means for detecting a Coriolis' force, for suppressing a current flowing in and out of said common terminal so as to prevent the current from flowing in and out of a side of said reference voltage generator.