| 摘要 |
PURPOSE:To electrically compensate the nonrectilinear conversion characteristics of a variable capacity type sensor, by using a differential conversion circuit for a conversion circuit which converts the output of variable capacity type sensor to an electric current signal and making feedback of output signal between these differential inputs. CONSTITUTION:Outputs of an AC power source 101 controlled by a differential amplifier 102 is impressed to the variable capacity elements 103 and 104 whose electrostatic capacity is differentially varied. Waves of currents which are proportional to capacities of variable capacity elements 103 and 104 are detected by diodes 105-108, amplified by a differential amplifier 122 as a difference from a reference voltage e0, and value of current passing through between line terminals 128 and 129 is changed. Terminal voltage of a resistor 127 is given to nonreversible input of the differential amplifier 102 through a resistor 134, and a negative feedback as an entire circuit is provided. And terminal voltage of the resistor 127 is given through a potentiometer 135 to the differential amplifier 122 as a positive feedback or a negative feedback, and therefore, nonrectilinear conversion characteristics of the variable capacity elements 103 and 104 are compensated. |
