| 摘要 |
PURPOSE:To simplify control circuits by providing multipliers which perform multiplication including signs of outputted electric signals and control input signals for driving each coil, and amplifying sections which amplify the output signals of the multipliers and drive the coils for the generation of lines of magnetic force. CONSTITUTION:When magnetic field detecting elements 4-i provided at specified positions of coils 3-i detect magnetic fields generated by magnets 7 being in a movable part 1 or a stationary part 2, electric signals with levels corresponding to the magnitude and direction of the magnetic fields are sent out to multipliers 5-i. On this occasion the levels are not limited to positives, and negatives can also do. Next signals outputted by the multipliers 5-i are amplified up to a level necessary and sufficient to drive the coils 3-i to obtain driving signals and sent out to the coils 3-i. Namely the magnitude and direction of lines of magnetic force which the coils 3-i generate are decided, on the basis of the products of control input signals with electric signals being the detected results of the magnetic field detecting elements 4-i. |
