GAIN CONTROL METHOD FOR OSCILLATION-TYPE SENSOR, OSCILLATION-TYPE SENSOR DEVICE, EVAPORATED FUEL STATE DETECTOR, AND CONTROL UNIT FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide an oscillation-type sensor device having a simple constitution, capable of measuring over a wide range of detection, at high resolution.;SOLUTION: This oscillation-type sensor device is provided with an oscillation-type sensor 10; a base oscillation signal generating circuit 25 for generating a base oscillation signal to be output; signal generating circuits 21, 22, 23 for combining a sensor oscillation signal with the base oscillation signal for generating a beat signal, having a beat frequency, a counter 30 for measuring a period of the beat signal; and a physical quantity calculating part 27 for calculating physical quantities, measured from the period of the beat signal and the period of the base oscillation signal. The base oscillation signal generating circuit 25 changes the frequency of the base oscillation signal, and the physical quantity calculating part 27 calculates physical quantities, based on the changed period of the base oscillation signal.;COPYRIGHT: (C)2008,JPO&INPIT