| 摘要 |
PURPOSE:To prevent a storage area from being damaged because of vibration and shock by controlling damping force generated in a voice coil via a diode in a contact, start stop magnetic disc device. CONSTITUTION:When a power supply turns off, relay contacts 2, 4 are changed over, a voice coil 3 is disconnected from a drive amplifier 5, and a current returning a magnetic head from the storage area of the disc to the stop area to the coil 3 via the diode 7. In this case, if the vibration and shock returning the magnetic head to the storage area is applied, the characteristic of the counter electromotive force generated in the coil 3 is changed, the diode 10 is biased forward to conduct a current to the coil 3 and to generate damping force. The diode 10 is reverse biased to the shock and the vibration in the opposite direction not to conduct and generate no damping force. Thus, the damping is applied only to the movement to the storage area against the shock and the vibration at the turning off of the power supply and the generation of the damage to the storage area of the disc is prevented. |
