| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To continuously and highly sensitively detect a D.C. current to a high frequency through the use of a flux gate magnetic sensor. <P>SOLUTION: A first current detecting means mainly detects a value of a current passing through a signal line from a D.C. current to the vicinity of a prescribed frequency band. A second current detecting means mainly detects a value of a current of a frequency higher than the vicinity of the prescribed frequency band. At this time, the first current detecting means comprises the flux gate magnetic sensor 9; a drive circuit 10 for supplying the flux gate magnetic sensor with a drive current of a frequency higher than the prescribed frequency band; and a magnetic flux concentrator 30. Since the magnetic flux concentrator 30 has a relatively high magnetic permeability when the frequency of the current of the signal line lies between a D.C. current and the vicinity of the prescribed frequency band and a relatively low magnetic permeability when it is at the frequency of the drive current, magnetic flux generated by the drive current does not leak to the magnetic flux concentrator 30. Therefore it is possible to effectively achieve high sensitivity through the use of the magnetic flux concentrator 30. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
