| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic sensor capable of highly accurate measurement from low flux densities to high flux ones even through the use of a Hall device. SOLUTION: A switching circuit 20 monitors the limit of a measuring range of a Hall voltage output from the Hall device H via an output circuit 10 and changes a drive current for driving the hall device H by performing switching operation on switching elements S1-S4 in the case that the Hall voltage is judged to exceed the limit of the measuring range. At this switching, required accuracy is secured by raising the Hall voltage by raising the drive current to raise apparent sensitivity on the side of low flux densities. On the side of high flux densities, a measurable range is extended to the side of high flux densities by lowering the drive current to lower apparent sensitivity. COPYRIGHT: (C)2006,JPO&NCIPI
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