| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a highly sensitive detector that needs no precise control on a distance between a metallic piece and a sensor by using as a sensor an amorphous metallic wire that is characterized by a magnetic impedance effect and that is formed by folding along the contours of the outer circumference of a passage. SOLUTION: An amorphous metallic wire with an MI effect is used in a semicircular coil as a sensor 10 of a detector for passing Pachinko steel balls 20. In other words, the coil which is formed by repeatedly folding an amorphous metallic wire in a semicircular shape is connected at one end 10-1 to one input of a detection circuit 100, and at the other end 10-2 to the other input. The magnetic impedance wire of the amorphous metallic wire sensitively reacts with a magnetic field received from the outside, if excited by a high frequency current having a resultant impedance of a few MHz or above between an internal inductance component and a skin resistance/inner resistance component, and passes into a resultant impedance proportional to the outside magnetic field.</p> |
