Patent ID: 7031356

Claim:
A temperature controller used in an optical-communication device for conforming a current temperature, comprising: a temperature sensor having a NTC sensor and a PTC sensor on a single PCB for detecting the current temperature; and, a temperature-comparison section for comparing the current temperature detected by the temperature sensor with a predetermined temperature indicative of a proper operating temperature for the device, the temperature-comparison section comprising, a differential amplifier for outputting a difference between signals which are inputted respectively into anode and cathode terminals thereof; a first resistance pad connected to the temperature sensor; a second resistance pad connected to the anode terminal of the differential amplifier and spaced from the first resistance pad; a third resistance pad connected to the cathode terminal of the differential amplifier and spaced from the first and second resistance pads; and, a fourth resistance pad for receiving a signal corresponding to the predetermined temperature and spaced from the first, second, and third resistance pads, wherein the first to fourth resistance pads are short-circuited with one another selectively according to one of the NTC or PTC sensors so as to vary the polarity of the signals inputted into the differential amplifier.