| 摘要 |
PURPOSE:To enable to perform an accurate measurement of body heat, by a method wherein a change in resistance of a thermistor is converted into the number of pulses which is operated by a micrometer. CONSTITUTION:A micrometer IC1 converts a voltage into a frequency, and a frequency f0, corresponding to a voltage inputted from a pin P7, is outputted from a pin P3. Then, constants of a voltage +V2 and a resistance R2 are set so that, through a change in resistance due to temperature of a thermistor 2, an input voltage V0 to the P7, attains 1,320V at 35 deg.C and 1,444V at 40 deg.C. Against the aboves, resistances R1 and R5 are set so that an oscillating output frequency f0 attains 4,105Hz at 35 deg.C and 4,490Hz at 40 deg.C. As a result, the changing rate of the frequency f0 is set to 77Hz/ deg.C. A high precise temperature detecting circuit is obtained by measuring and operating the frequency f0 by means of a microprocessor 1. This enables to perform a high-precise measurement of body heat. |
