| 摘要 |
PROBLEM TO BE SOLVED: To diminish the dispersion of characteristics by causing an hourglass- shaped magnetic core on which a coil has been wound, and a cylindrical magnet having positioning protrusions at specified axial-direction positions of its internal wall to constitute a linearity coil, and inserting the hourglass-shaped magnetic core into the cylindrical magnet and fixing the hourglass-shaped magnetic core to the specified axial-direction positions of the cylindrical magnet by the positioning protrusions. SOLUTION: On an hourglass-shaped magnetic core 1 made of ferrite, a coil 2 of polyurethane-covered copper wire is wound. To a pair of lead terminals 4 implanted in one flange of the magnetic core 1, both ends of the coil 2 are connected and soldered. Besides, a plurality of positioning protrusions 5 for a magnetic core 1 is formed on the internal wall of a cylindrical magnet 3 made of barium ferrite, and the magnetic core 1 inserted into the cylindricaly magnet 3 is positioned at a specified axial-direction position of the cylindrical magnet 3, and is fixed in that state by a resin 6 infected between the magnetic core 1 and the cylindrical magnet 3. |
