| 摘要 |
<p>PROBLEM TO BE SOLVED: To extremely reduced fluctuation in a digital detection signal without using a correction circuit even when the voltage of a power supply is fluctuated, to simplify a circuit configuration, to reduce power consumption, to eliminate the need for increasing the dimensions of a sensor, to simplify circuit adjustment, and to appropriately maintain the reliability of a circuit system in the flow-rate sensor circuit system. SOLUTION: A sensor circuit system is provided with an analog circuit at a sensor side that includes a flow-rate detection circuit for outputting an analog electric signal corresponding to a flow rate and a constant-voltage circuit for the flow-rate detection circuit, and a digital circuit at a microcomputer side that includes an A/D conversion circuit for converting the analog electric signal being outputted from the flow-rate detection circuit to a digital electric signal. In the sensor circuit system, the output of the constant-voltage circuit is used as a + side reference voltage of the A/D conversion circuit, and the output of the constant-voltage circuit is utilized as reference in the digital circuit, thus obtaining a digital detection signal corresponding to the flow rate.</p> |
