| 摘要 |
PURPOSE:To return a head to a leading zone automatically only by turning off a power switch by converting the inertial energy of a magnetic disk which rotates by its inertia after current supply is ceased into electric energy and returning the head to the landing zone. CONSTITUTION:When the power switch is turned off, a power source abnormality detecting circuit 10 detects power source abnormality and sends a detection signal to a CPU9. The CPU9 switches a switching circuit 11 from a spindle motor driving circuit 3 to a rectifying circuit 12. Consequently, the inertial energy of a spindle motor 2 is connected into the induced electromotive force of a field coil and then rectified by a rectifying circuit 12 into a direct current. Its electric output is supplied to a stepping motor driving circuit 5 through a power source control circuit 13 and the CPU9 to drive the stepping motor 4, returning the head to the landing zone on the magnetic disk. A head lock solenoid 7 is operated through a solenoid driving circuit 6 after the head returns, thereby locking the head. |
