| 摘要 |
<P>PROBLEM TO BE SOLVED: To exclude influence of dispersion in magnetic characteristics of a core in detection of an external magnetic field, and to improve the detection accuracy of the external magnetic field. <P>SOLUTION: An excitation signal of a triangular wave capable of periodically saturating the core is applied to the core of a flux gate sensor, the intensity of a magnetic field in the core is changed as shown by a characteristic line S1, and induced electromotive force generated by the change of the magnetic field intensity is extracted as a detection signal S2. Further, a detection point Dp during a period that the detection signal S2 reaches a peak on the positive side and is immediately changed from the peak to a zero level and a detection point Dn during a period that the detection signal S2 reaches a peak on the negative side and is immediately changed from the peak to the zero level are detected, and an output pulse signal S3 rising at the detection point Dp and trailing at the detection point Dn is generated. Then, a size and a direction of a detected current (external magnetic field) are recognized based on a pulse width W of the output pulse signal S3 or a pulse duty ratio. <P>COPYRIGHT: (C)2012,JPO&INPIT |
