| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a magnetic balance type current sensor with improved sensitivity capable of accurately sensing a target current even if the value of the current is close to zero. <P>SOLUTION: A magnetic balance type current sensor includes: a magnetic sensor element 21 formed in a sensor chip 12 and arranged such that the output thereof changes in proportion to a target magnetic field Ha induced by a target current Ia flowing through a bus bar 11; an electromagnet 14 which generates a counter magnetic field Hb; a supply means 40, formed in a circuit chip 15, for supplying a counter current to the electromagnet 14; and a bias magnet 13 which generates a bias magnetic field Hc having a magnetic field component of constant magnitude and direction that is in parallel with the direction of the target magnetic field Ha acting on the magnetic sensor element 21. The magnetic sensor element 21 is a magnetoresistive effect element having a magnetic film thereon. The electromagnet 14 cancels out a composite magnetic field Hd, comprising the target magnetic field Ha and the bias magnetic field Hc, with the counter magnetic field Hb. <P>COPYRIGHT: (C)2013,JPO&INPIT |
