PURPOSE: To provide a signal processing circuit for a position sensor for extending the life of a slide resistor by suppressing the generation of a slide noise attributed to wear dust of a resistor and changes in output voltage characteristics.

CONSTITUTION: A signal processing circuit 20 is made up of resistors 21, 22 and 23, an operational amplifier 24 and a changeover switch 25. The resistor 21 functions as pullup resistance when the changeover switch 25 is turned to the position (a) and the resistor 22 functions as pulldown resistance when the changeover switch 25 is turned to position (b). When a sensor section 10 is used, a brush slides on a resistor section 11 with the rotation of a rotor while a resistance value of a contact resistor section 12 changes by a wear dust generated by a friction between the brush and the resistor section 11 to generate a slide noise. To correct changes in the upper side output and the lower side output of a sensor output voltage as caused by the slide noise, the resistor 21 and the resistor 22 are used to calculate a resistance value of the contact resistor section 12 and the sensor output voltage containing no slide noise with an arithmetic section.