发明名称 |
AUTOMATIC DEMAGNETIZING SYSTEM FOR STRUCTURE |
摘要 |
PROBLEM TO BE SOLVED: To provide a demagnetizing system for detecting the change in the local permanent magnetism of a hollow structure and maintaining a magnetic field appearing in the outside minimum at all these. SOLUTION: A detection signal of a magnetic detector 5 for individual coil control is divided into an induction component and a permanent component, for the noise and other correction part 14. The change amount of the permanent component is calculated and compared with a target value 9 through a subtracter 10. Power supply to each demagnetizing coil 7 is so controlled that the permanent component becomes equal to the target value 9. A detection signal of a magnetic detector 6 for block coil control is divided into an induction component and a permanent component for the noise and other correction part 22. The change amount of the permanent component is calculated and compared with a target value through a subtracter 16. Then a current command correction signal for block coil control is obtained and added to a signal from a block control system 19 by an adder 21, thereby controlling the current to be conducted to a block coil 8. |
申请公布号 |
JP2000021632(A) |
申请公布日期 |
2000.01.21 |
申请号 |
JP19980184862 |
申请日期 |
1998.06.30 |
申请人 |
HITACHI LTD |
发明人 |
ONO ATSUSHI;MURAKAMI HAYATA;TANAKA TOSHIO |
分类号 |
B63G9/06;B63J99/00;H01F13/00;(IPC1-7):H01F13/00;B63J5/00 |
主分类号 |
B63G9/06 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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