摘要 |
A drive means comprising a movable part and a fixed part provided with a stator winding and a magnet yoke with a magnetic gap. A soft-iron magnetic portion is arranged in the magnetic gap. A current generator generates a first current for a stator winding and a second current for another stator winding, the sum of the magnitudes of the two currents being constant. The reluctance effect causes each of two soft-iron magnetic portions to be pulled into an individual magnetic gap driven by one of the two currents. The two reluctance forces vary quadraticly with the two currents, but due to the fact that the net force is the difference between them, this net force will be linearly dependent on the currents. It is suitable to allow the two currents to come from the same amplifier stage, which is push-pull coupled. |