| 摘要 |
PURPOSE:To reduce heat generation of a coil and to obtain a small-sized and lightweight linear motor itself by making adjustment to apply stylus force of 1/2 of maximum stylus force to a record reproducing stylus when the linear motor is not working. CONSTITUTION:Current applied to a drive coil 26 is made to -I1, and a vertical linear motor 10 is driven by this current, and negative stylus force -F(g)/2 is generated to lift up a record reproducing stylus. Under this condition, the position of a balance weight is adjusted to take zero balance of a tone arm, and stylus force is returned to zero. To increase the stylus force from 0 to F(g), the quantity and direction of current applied to the coil 26 is adjusted to draw the current from -I1 to 0, and at the same time, the direction of flow of the current is reversed from I1=0, and increased to become +I1. Thus when current is -I1, stylus force is 0, when current does not flow, stylus force is F(g)/2, and when the direction of current is reversed and at +I1, stylus force of F(g) can be given to a record reproducing stylus.
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