| 摘要 |
PURPOSE:To prevent a damage of an information recording disk or a pick up by turning on a switch disposed in a signal path in a driving control circuit only when voltage value of a positive and negative power source fed to the driving control circuit substantially coincides or only when an individual power source and a standard voltage take a desired ratio. CONSTITUTION:A driving control signal 14 is fed to an operation amplifier 6, and an output of the operation amplifier 6 is impressed to a pick up actuator coil 13 of a video disk player through a electric current booster constituted by transistors 11, 12. Comparators 25, 26 are constituted as window comparators, and only when a voltage level of V5 is stuated within the voltage level of V6 and V7, an output is 'H'. Only when an output of the window comparator is 'H', an FET 23 disposed between the amplifier 6 and the electric current booster is turned on. In this manner, even when first transitions of a positive power source V1 and a negative power source V3 are different and an unbalance is generated, a damage in the disk and the pick up can be prevented without impressing an abnormal electric current to the coil 13. |
