| 摘要 |
PURPOSE:To suppress the power coefficient of a detection coil during a large amplitude, by defining the relation among the turn width of a driving coil, the set value of the magnetic gap of a magnetic circuit and the turn width of a detecting coil respectively. CONSTITUTION:The turn width of a detecting coil 4 is set to that the absolute value (b) of the difference between the turn width of a detecting coil 4 and the set value of the magnetic gap 1A of a magnetic circuit 1 is larger than the absolute value (a) of the difference between the set value of the gap 1A and the turn width of a driving coil 3. The distribution is constant for the magnetic density of the transmitted magnetic flux within the set width of the gap 1A and is decreased outside the set value. Therefore the power coefficient is constant to the coil 3 up to the difference (a) between the turn width of the coil 3 and the set value of the gap 1A and then decreases when it exceeds the difference (a). That is, the amplitude margin of the coil 3 is equal to (a). In this case, the amplitude margin of the coil 4 is equal to the difference between the gap 1A and the turn width of the coil 4, that is, b<a is obtained. Thus the power coefficient of the coil 4 does not change up to (b) although the power coefficient of the coil 3 varies. |
