| 摘要 |
<p>PURPOSE:To obtain a small-sized inexpensive current detector having extremely high accuracy, by generating a pulse signal in the detection coil of a magnetism- sensitive element at the point of time when the next positive magnetic field acts when the negative magnetic field due to a current to the detected is larger than a bias magnetic field. CONSTITUTION:At first, a constant bias magnetic field HDC is always allowed to act on a magnetism-sensitive element 1. Herein, when the external magnetic field HAC generated by the AC current I to be detected flowing to an exciting coil 3 is smaller than the absolute value of the max. peak value thereof, any special phenomenon is not generated in the element 1. However, when the magnetic field HAC larger than HDC acts, at first, a negative magnetic field HR acts on the element 1 and a part low in coercive force is transformed in a negative direction and again reversed in a positive direction by a positive magnetic field HS acting in succession. This transformation speed is especially rapid. Therefore, since a steep pulse signal VS is induced in a detection coil 2 at the point of time when a limit magnetic field HL necessary for generating transformation acts, by detecting the signal VS, it is discriminated that the prescribed current to be detected is supplied.</p> |
