Patent ID: 6957589
Filing Date: 2005-10-25
Classification: G01L

Abstract:
1. A temperature compensator of torque sensor including a pair of coils which are connected to an AC power supply circuit via transistors and in which inductances change in opposite directions depending on torgue, and a torque detecting means arranged and constructed to obtain a voltage difference between a first voltage and a second voltage output via smoothing circuits based on changes in inductance of each of the pair of coils and outputs as a torque detection voltage, the temperature compensator comprising: a correcting voltage extracting means for extracting a voltage between terminals of a transistor in the AC power supply circuit as a temperature correcting voltage; and a correcting means for correcting the torque detection voltage based on a temperature correcting voltage extracted by the correcting voltage extracting means, wherein the AC power supply circuit is constructed such that an emitter terminal of a PNP type transistor is connected together with a DC power supply to a base terminal of an NPN type transistor, an emitter terminal of which is connected to the pair of coils and a collector terminal of which is connected to the DC power supply while an AC power supply is connected to a base terminal of the PNP type transistor, and the correcting voltage extracting means is arranged and constructed to extract a collector/emitter voltage of the PNP type transistor as a temperature correcting voltage.