| 摘要 |
PURPOSE:To prevent the destruction of a floppy disk by using a circuit which produces a motor-on signal and a circuit which produces a motor-off signal to start and stop a spindle motor. CONSTITUTION:When a power supply is applied in a loading state of a floppy disk, the output of a receiver 1 is kept at ''L'' before a time point t1. While the input of a receiver 7 is changed to ''H'' from ''L'' when the power supply is applied, and the output of the receiver 7 is applied to a delay cirlcuit 9. The output of the circuit 9 changed to ''H'' from ''L'' at a time point (t1+td1), and an AND circuit 10 produces a pulse of time width td1. This pulse is delayed by the time td2 through a delay circuit 3 and applied to a flip-flop circuit 5 to be changed to ''H'' from ''L'' at a time point (t1+td2). Then the circuit 5 is reset when a ready signal B showing an ON state of a spindle motor, and the output of a driver 6 is set at a signal level of an OFF state. In case the floppy disk is inserted after the power supply is applied, a pulse is produced from an NAND circuit 4 to start the revolution of the spindle motor. In such a way, prevents the engine breakdown of the floppy disk and the generation of a read/write fault are prevented. |
