| 摘要 |
PURPOSE:To obtain a stable dynamic characteristic compensating the gradient to a movable element by a method wherein the values of currents driving the movable element are controlled according to an output of an angle detector which detects the gradient to the horizontal level in the direction in which the movable element travels. CONSTITUTION:A stater 1 is composed of two yorks 2A, 2B which are arranged in parallel through a predetermined spacing and whose both ends are joined with each other, and a permanent magnet 3 fitted inside the york 2B on one side, and the movable element 4 having a field coil which is wound round a bobbin 5 is slidably supported on the york 2A. In addition, near the center of the york 2B is furnished the angle detector 7 having, for example, a resistor 8 and a weight attached with a contact piece 11. An angle of inclination theta made by the movable element 4 to the horizontal level of the york 2A in the direction in which the element moves can be detected by means of this anble detector 7, and the values of the driving currents passed through the filled coil 6 is controlled at the predetermined control section according to the direction in which the york 2A inclines and the width of the angle of inclination theta. |
