| 摘要 |
PURPOSE:To offer an electromechanical transducer vibrating efficiently to a low frequency and with less assembling man-hour by fitting freely a permanent magnet in the inside of an annular coil and supporting the central plane between magnetic poles in the state that the plane spaces a plane having maximum magnetic flux density in conducting the coil. CONSTITUTION:The disc form permanent magnet 1 is fitted freely while a magnetic gap 4 is formed in the inside of the annular coil 13, the permanent magnet 1 is supported by a damper 7 in the state to hold a gap 16 between the plane 14 having the maximum density at the annular section of magnetic flux generated therearound in flowing a current to the annular coil 13 and a center plane 15 in parallel with both faces of the disc at the center between both end poles 10, 10' of the permanent magnet 1. In flowing a voice current to the annular coil 13, the magnetic flux is caused around the inside and outside of the annular coil 13, and the magnetic plane 14 of the annular coil 13 and the center plane 15 of the permanent 1 magnet receive force in the direction that they are made close to each other at the moment when the direction of the magnetic flux is the same as the direction of the North Pole of the permanent magnet 1, and they receive force in the direction that they are parted when the directions are opposite, and the permanent magnet 1 is displaced and vibrated in response to the voice current. |
