Wire breaking detection method for temperature sensor and temperature sensing apparatus for using the method

摘要

A temperature sensing apparatus comprises a temperature sensor, a current measuring device and temperature detection circuit. The temperature sensor contains a thermal resistor that is disposed near a motor and outputs voltages acting to the thermal resistor. The current measuring device measures quantity of current that is applied to the motor. The temperature detection circuit detects temperature of the motor according to the output voltages from the temperature sensor. And, the temperature detection circuit judges whether a predetermined quantity of current is applied to the motor during a predetermined time. When the predetermined quantity of current is applied to the motor during the predetermined time, the temperature detection circuit compares a temperature detected by the current measuring device with a predetermined temperature. When the detected temperature is lower than the predetermined temperature, the temperature detection circuit decides a wire of the thermal resistor breaks.