| 摘要 |
<p>PURPOSE:To protect individual magnetic sensors from the effect of a magnetic field in other phases by surrounding a bus and a magnetic sensor with a conductive cylindrical shield member while a specified magnetic body is arranged between the shield members. CONSTITUTION:As current flows through buses 1, 2 and 3, circumferential magnetic fields are separately formed inside the shield members 9, 10 and 11 and on the circumference thereof centered on the buses 1, 2 and 3 with a magnetic flux passing through second magnetic bodies 13, 14 and 15 from a magnetic body as common magnetic path. The shield members 9, 10 and 11 shield a.c. magnetic fields separately. For example, the shield member 9 prevents external leakage of a magnetic flux generated in the bus 1 while checking the infiltration of any magnetic flux generated in the buses 2 and 3. This permits the magnetic flux leaked from the buses 2 and 3 to pass through the second magnetic body 13 thereby minimizing components in the sensitivity direction of a magnetic sensor 4. Therefore, the fluxes in the shield members 9, 10 and 11 are formed in concentric circles and detected with magnetic sensors 4, 5 and 6 respectively.</p> |
