| 摘要 |
<p>PURPOSE: To compensate for and improve the linearity of a detection circuit detecting a current in a non-contact manner or a circuit detecting a magnetic change. CONSTITUTION: This detecting circuit is in the constitution of a bridge comprising a semiconductor magnetoresistance element R11 and three reference resistors R12, R13 and R14 to convert a near-by passing current or a magnetic flux change to a voltage signal by the magnetoresistance element. In the detecting circuit, an output of an amplifier circuit 2 for amplifying an output terminal of the bridge and a constant source voltage are negatively fed back by a synchronous addition circuit 3, which are impressed to an input terminal of a power source of the bridge thereby improving the linearity. The source voltage impressed to the synchronous addition circuit 3 is an output of a temperature compensation circuit 4 consisting of a semiconductor element and resistors, so that the temperature is compensated for as well as the linearity. The linearity can thus by compensated for in a wide dynamic range simply by adding the simple addition circuit, achieving high accuracy.</p> |
