LINEAR VOICE COIL ACTUATOR WITH BURNING PREVENTIVE COIL, ITS MANUFACTURING METHOD AND ITS APPLICATION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a linear voice coil actuator with a burning preventive coil which can generate a force of as large as 100 kg by the application of a current of not larger than approximately 2 ampere and can operate continuously for a long time without burning of the coil, its manufacturing method and its application method. SOLUTION: The flat planes 32 and 38 of an electric coil 20 for generating an electric field are placed respectively in parallel with the flat planes 34 and 40 of a magnetically unsaturated permanent magnet 30 for generating a magnetic field so as to form gaps 36 and 42. When a current is not applied to the electric coil 20, distances d' and d" of the gaps 36 and 42 are 0.75 mm. Even if a current of approximately 2 ampere is applied and the electric coil 20 is deformed, the sufficient distances d' and d" can be secured. With this constitution, even if a force of as large as 100 kg is continuously generated by the interaction of the electric field generated by the electric coil 20 and the magnetic field generated by the magnet, the burning of the electric coil 20 can be avoided.