| 摘要 |
PURPOSE:To improve low flutter by providing a rotating speed control circuit for a motor, rotating the motor more than one revolution of the regular rotation and reverse rotation at a speed less than the standard number of revolutions at the time of chucking a center core to a turntable. CONSTITUTION:The rotating speed control circuit for the motor consists of a switch control circuit 30, switch circuit 31, reference clock generator 32 and motor control circuit 33, etc. When the circuit 30 is fed by a signal of detection that the center core of a tape cassette is mounted onto the turntable, firstly, a switch 31A of the circuit 31 is switched over to a resistor RF1 having a large resistance value, and then the reference clock to be fed to the circuit 33 from the generator 32 is low in frequency, so that the number of revolutions of the motor 26 is less than the standard number of revolutions and this rotation is made for more than a fixed period of time. Secondly, a switch 31B is switched over to RR2 of a large resistance value, reversing the rotation direction. In this way, the center core can be chucked to the turntable under the normal state, and the table speed becomes constant, thus eventually improving low flutter.
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