Patent ID: 9291666
Filing Date: 2016-03-22
CPC Classification: G01R

Claim Text:
1. A detecting device, comprising: a detecting part configured to detect a change in an object to be detected so as to output a detection signal; an amplifying part configured to amplify the detection signal output from the detecting part so as to output a first amplification signal; a reference voltage supply part configured to supply a reference voltage to the amplifying part, the reference voltage being input to the amplifying part so as to be output as a second amplification signal; a switching part configured to switch a connection between the detecting part and the amplifying part or a connection between the amplifying part and the reference voltage supply part based on a control signal input thereto; and a comparing part configured to compare a predetermined amplification factor in the amplifying part, with an amplification factor obtained from the second amplification signal so as to output the comparison result as a comparison signal, wherein the detecting part comprises a magnetic sensor, wherein the magnetic sensor comprises a bridge circuit comprising a first magnetic sensor element to a fourth magnetic sensor element, and the reference voltage supply part generates a first reference voltage corresponding to a first divided voltage of the first magnetic sensor element and the second magnetic sensor element, and a second reference voltage corresponding to a second divided voltage of the third magnetic sensor element and the fourth magnetic sensor element in an initial state, and wherein the comparing part is configured to compare a third amplification signal obtained by differentially amplifying the first divided voltage and the second divided voltage by the amplifying part, with a fourth amplification signal obtained by differentially amplifying the first divided voltage and the second reference voltage by the amplifying part so as to output the comparison signal.