PURPOSE: To realize a large inductance by movably disposing a magnet having different poles joined together so as to be integrated in a magnetic space of a magnetic core.
CONSTITUTION: The movable magnet 4 has the pair of magnets 4a, 4b with the respective different poles connected together so as to be integrated in the magnet side. A connecting surface 5 is supported by a resilient support member so as to coincide with the center of a intersecting direction in the space 3. When a sound current is conducted through a driving coil 2, on both end surfaces of the magnetic core 1 facing the space 3, the N, S magnetic poles appear alternately, thereby, the movable magnet 4 receives the attraction and repulsion and vibrates in the direction shown by an arrow A. When the diaphragm is connected to the movable magnet 4, it operates as a sound element. The magnet flux formed by the two magnets 4a, 4b sounding element. The magnet flux formed by the two magnets 4a, 4b constituting the movable magnet 4 is shortened on the end surface of the magnetic core 1, and directed to the connecting different poles, so that it does not pass through the cycle magnetic path of the magnetic core 1 interlinked with the coil 2. Accordingly, an unidirectional direct current magnetic flux passes through the magnetic core 1, a magnetic saturation is generated and the large inductance is obtained without deteriorating the inductance.
JPS62198300 | ELECTROACOUSTIC TRANSDUCER |