| 摘要 |
PURPOSE:To prevent abnormal data from being written by detecting a drop in a rectified power source output and setting a writing voltage in an unwritten state when it is detected. CONSTITUTION:If a power failure occures during the operation of a disk 1, this power failure is detected by a power-failure detecting circuit 18 as a drop in the output voltage DC2 of a rectifier 17 to generate a power-failure detection signal ES. This detection signal ES energized a relay circuit 19 to change a transfer contact 20 from a write power source 15 side over to an earth side, so that a write power source voltage WBV applied to a write control circuit 11 is held at the earth potential instantaneously. Thus an unwritten state is set to prevent an abnormal write signal from being supplied to a head 3 even if the write control circuit 11 malfunctions owing to a drop in logical driving voltage LMV. Thus, the abnormal data is prevented from being written. |
