| 摘要 |
PURPOSE:To prevent a malfunction of a revolution control system which is due to the large fluctuation range of a driving voltage, by setting a constant voltage power supply in series to a spindle motor to prevent a shift of revolution between the inner and outer circumferences of a disk. CONSTITUTION:A zener diode 13 connected between a spindle motor 12 and an earth is adversely biased by a power supply +V and therefore forms a constant voltage power supply 14 of 3.6V, for example. This power supply 14 is connected in series to the motor 12, and therefore the motor 12 is biased by the fixed voltage E generated from the power supply 14. For instance, the diode 13 of 3.6V is used for the power supply 14, and therefore the fluctuation degree of the control signal is reduced greatly down to about 0.76dB to the motor 12. In such a way, the fluctuation of the control voltage can be virtually reduced to a revolution change of the motor 12. Therefore, a shift of revolution can be prevented between the inner and outer circumferences of a disk. |
