| 摘要 |
<p>PURPOSE: To stop supplying electric power from a host device side on the input/ output device side safely. CONSTITUTION: With a main switch SW1 ON, a switching circuit 14 switches a power source 12 as the power supply source for a power line 209 and turns ON a switch SW2 to turn ON a switch SW3. Consequently, when the electric power is supplied from the host device 10 to a disk device 30, a switch operating circuit 54 turns ON a switch SW4. When the power supply from the power source 12 is cut off, the switching circuit 14 switches the power supply to a battery 13 and turns OFF the switch SW2. At this time, if a voltage detecting circuit 53 detects the voltage variation on the signal line 51, the switch operating circuit 54 turns OFF the switch SW4 on the operation end of the disk device 30 to turn OFF the switch SW3, thereby turning OFF only the power source for the side of the device 30.</p> |
