| 摘要 |
PURPOSE:To obtain a thermistor temperature detection device using an A/D converter which can detect temperature accurately without being affected by fluctuation of power supply voltage and gain of an amplifier. CONSTITUTION:A potential of each of connection points P, Q, and S is read by an A/D converter 19 through a selection switch 17 and an amplifier 18 and is converted to digital signal. A control operation circuit 20 switches the selection switch 17 in sequence and reads a digital signal corresponding to the potential of each of the connection points P, Q, and S, calculates a resistance of a thermistor 14 based on the read data, and then obtains temperature. Since the resistance of the thermistor 14 is calculated from the potential of each of the connection points P, Q, and S, temperature can be detected accurately without being affected by fluctuation, etc., of power supply voltage and gain of an amplifier. |
