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摘要

PROBLEM TO BE SOLVED: To provide a low-cost magnetic proportion system current sensor in which gain adjustment is simplified by eliminating the change in offset voltage resulting from the gain adjustment because it is not necessary to change the drive current of a magnetic detection element such as a hall element when the gain adjustment is performed.;SOLUTION: When adjusting the magnetic proportion system current sensor, first, a drive current I_C of a hall element 16 is fixed, then, influence of an offset voltage is adjusted by adjusting a resistance of a resistor R₂ of an intermediate voltage generating circuit 26, and thereafter the gain of a differential amplifier 22 is adjusted by adjusting a resistance of a resistor R_T (gain adjustment is performed). Because the drive current I_C of the hall element 16 does not change owing to the adjustment of the gain of the differential amplifier 22, it is not necessary to consider the change in the offset voltage resulting from the change in the drive current I_C. Namely, no repeated offset adjustment or complex calculation in consideration of the same is required, and thus a gain adjustment process is simplified.;COPYRIGHT: (C)2010,JPO&INPIT