| 摘要 |
The invention relates to an actuation magnet for a printing stylus (11) of a matrix printer, in which an armature (12) of the plunger type connected to the printing stylus (11) is guided in the cylindrical inner space of two soft-magnetic pole pieces (6,7) enclosed by a direct current energizing coil (14), the space between these pole sleeves (6,7) being bridged by a spacer element (17), which consists of a material, whose magnetic conductance or permeance is considerably smaller than that of the material of the pole sleeves (6,7). The movement force exerted on the soft-magnetic armature (12) is increased in that the distance between the ends of a yoke (13) is bridged by a permanent magnet (17), whose pole faces engage the free ends of the yoke (13), and in that the energization of the energizing coil (14) produces a magnetic flux, which has a sense opposite to a magnetic flux of the permanent magnet (17) through the yoke (13).
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