DISCONNECTION DETECTION CIRCUIT FOR SENSOR

摘要

PROBLEM TO BE SOLVED: To detect disconnection of a sensor before a motor is rotated by converting an output waveform of a sensor into a DC voltage in accordance with the output waveform and comparing the DC voltage with a reference voltage. SOLUTION: An input A to a disconnection detection circuit 5 is inputted to a non-reversal input terminal of a comparator 8 by way of a resistor 6 and also comparison reference voltage Vcc3 from a comparison reference voltage generator 7 is inputted to a reversal input terminal of the comparator 8. The comparison reference voltage Vcc3 and the input A are compared with each other and an output C of the comparator 8 is inputted to a filter circuit 10 as a conversion circuit. Moreover, the output of the filter circuit 10 is inputted to an input terminal of a reset IC 11 as a comparison circuit and a voltage of this input terminal and the reference voltage which had inside the reset IC 11 are compared with each other. As a result, the output of the reset IC 11 becomes a resolver disconnection detection signal E and disconnection of the rotation sensor can be detected.