| 摘要 |
PURPOSE:To attain the accurate measurement of the distance between an object and a detector even when the object is offset from a standard position due to winding, by providing an electromagnetic detector in which the levels of the detecting outputs from two sensing units are compared with each other and the distance is calculated from the selected one of two sensing outputs. CONSTITUTION:Suppose here that an object 2 to be detected winds so as to take a position offset from a standard position by a distance Za. In this case, the sensible area LA of a first sensor unit 1A is fully covered by the object 2, so that the magnetic reluctance between the first sensor unit 1A and the object 2 precisely corresponds to the distance therebetween. On the other hand, the sensible area LB of a second sensor unit 1B partly falls out of the object 2, so that the magnetic reluctance between the second sensor unit 1B and the object 2 takes a value greater than the value corresponding to the distance therebetween. Therefore, the output voltages VA1 and VB2 from reference reactors 8A and 8B are related to each other as VA1>VB2. In this case, the position of the object 2 is determined by a discrimination and operation circuit in accordance with the sensing output from the first sensor unit 1A. With this arrangement, it is possible to accurately sense the position of the object because the distance is calculated from the sensing output from the sensor unit the sensible area of which is fully covered by the object 2. |
