Patent ID: 6377056
Filing Date: 2002-04-23
Classification: G01D,G01L,G01P

Abstract:
An electrostatic capacitance type dynamic quantity sensor comprising:a dynamic quantity detection electrostatic capacitance element having an electrostatic capacitance Cs which changes according to a dynamic quantity, a reference electrostatic capacitance element forming a reference electrostatic capacitance CR, and a capacitance detection circuit outputting a dynamic quantity detection signal proportional to a reciprocal of the electrostatic capacitance Cs of said dynamic quantity detection electrostatic capacitance element, wherein said sensor has a circuit construction formed so that when said dynamic quantity detection electrostatic capacitance element displaces according to a dynamic quantity, electric charge quantities charged in said dynamic quantity detection electrostatic capacitance element and in said reference electrostatic capacitance element become unbalanced to produce a difference, and an output of said capacitance detection circuit changes according to the difference of electric charge quantity, and a charge and discharge circuit is provided which operates, using the output of said capacitance detection circuit, to change the output until the electric charge quantities in said dynamic quantity detection electrostatic capacitance element and in said reference electrostatic capacitance element become substantially equal.