| 摘要 |
<p>PROBLEM TO BE SOLVED: To avoid the problems of scattering of magnetic field measurement to positive and negative directions, increasing in measurement errors and requiring high accuracy in sensor positioning, depending on the positioning accuracy of an MI element due to zero magnetic field at the center, when a small window is opened in the middle of a primary conductor and MI element is put at the center. SOLUTION: In this invention, a notch is provided in the center part of a primary conductor 1 and a secondary conductor 1', and the primary conductor 1 and the secondary conductor 1' are integrated into one. A small window 2 is provided as an opening and a magnetic sensor, consisting of a pair of thin film MI elements 3 and 3' with different detection sensitivity directions, is placed in the small window 2. Even if a large current flows in the conductor which consists of the primary conductor 1 and the secondary conductor 1', the inside of the small window 2 is in a small magnetic field region, and the detection sensitivity of the thin film MI elements 3 and 3' remains optimum. Furthermore, by arranging one magnetic sensor 3 and the other magnetic sensor 3' canceling disturbance noise and thermal drift in the small magnetic field gradient, so as to impart detection sensitivities in different directions, a current output 6 can be attained by obtaining the difference between the sensor values of outputs of simple detection circuits 4 and 4'.</p> |
