| 摘要 |
PURPOSE:To obtain an apparatus in small size and light weight having quick response rate by applying AC field orthogonally to a secondary current to a secondary coil which is fixed to a movable piece in the iron core and induces said secondary current due to an AC current flowing into the primary coil. CONSTITUTION:An iron core 11 is provided at its center with a hole through which a movable piece 17 moves. A field magnet coil 13 is wound around a field magnet yoke 15, forming a field magnet means. A material having a high mechanical strength, light weight and small electrical resistance is desirable for the secondary coil 16. Therefore a high tensile aluminum etc. is used for the secondary coil. Even when directions of secondary current and AC magnetic field are charged from time to time, the secondary coil 16 receives a force always in the same direction and accordingly the movable piece 17 mounting the secondary coil 16 also moves in such direction. Thereby, a small size and light weight apparatus assuring quick response rate due to a small inertia can be obtained. |
