| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a sensor circuit which is a sensor used to find a thermal conduction parameter such as humidity or the like on the basis of a temperature change due to thermal conductivity, which improves the complicatedness and the accuracy of a conventional circuit by a low-temperature or high-temperature current pulse driving operation, which shortens the measuring time, which relaxes an environmental condition, which compensates an irregularity in the sensor and whose power consumption is low. SOLUTION: A first mode in which a reference voltage Vref is input, via a resistance R1 , to the negative terminal of a first operational amplifier A1 using a resistor sensor RS as a negative feedback resistance and in which an output V1 is selected by a switch S3 so as to obtain an ambient-temperature measured output is performed. A second mode in which a resistance variable VRX used to form a reference resistance equivalent to the resistor sensor RS at a prescribed high temperature is connected across the first operational amplifier A1 and a second operational amplifier A2 using a resistance R2 as a positive feedback resistance is performed. A CPU which computes an ambient temperature and a thermal conduction parameter on the basis of outputs in the respective modes performs a related-data processing operation, a circuit setting processing operation and a memory operation.</p> |
