| 摘要 |
PURPOSE:To maintain a clamping mechanism in releasing state for a specified time by converting rotational energy of a spindle motor in a magnetic disk device and applying current to a solenoid at the time of momentary break or momentary stop of a power source. CONSTITUTION:When the output of a power source 31 is stopped, power is not supplied to the spindle motor 32. However, the motor continues to rorate by inertia. Meanwhile, counter electromotive force generated by rotation is supplied to a coil 34 from the input terminal of the motor 32 through diodes 35a- 35f. Accordingly, the clamping mechanism 4 does not operate until the spindle motor becomes to have the rotation below specified number of rotation. Normally, time required until the head retreats to a retract zone is several hundreds milisec. However time required for the spindle motor 32 to become below specified number of rotation is several seconds to ten-odd sec, the clamping mechanism operates after the head has fully retreated to the retract zone. |
