PURPOSE: To detect temperature simply by a method wherein a constant current flows through a temperature measuring resistor and first and second reference resistors and voltages across resistors are detected to compare resistance values of the temperature measuring resistors and the first and second reference resistors.
CONSTITUTION: A thermistor circuit is made up of a thermistor 1 and a reference resistor 11. First and second resistors 12 and 13 with the resistance value the same as the thermistor 1 are provided at the zero and span points of the measuring range. Then, current from a power source 16 is changed over synchronizing changeover switches 18 and 20 and inputted sequentially into the first and second reference resistors 12 and 13 and the thermistor 1. A signal processing section 23 compare the resistance values of the thermistor 1 and the first and second reference resistors 12 and 13 to detect the temperature signal. Thus, temperature is determined from the resistance value of a temperature measuring resistor by being compared with the first and second reference resistors and determining the resistance values of the reference resistors sufficies thereby eliminating adjusting operation.
CHIYOU TOSHIICHIROU
SHIMIZU MASATO
| JPS4974990A | 1974-07-19 | |||
| JPS5443079A | 1979-04-05 |