| 摘要 |
PURPOSE:To avoid the erasion of data on a medium regardless of the application sequence of power supply set to a disk storage device, securing such a constitution where a read/write logic circuit can work only when a power supply of 5V is applied to the storage device. CONSTITUTION:The power of 5V is supplied to a disk storage device. When the power of 5V exceeds the level of the Zener voltage of a Zener diode 26, a base current flows to a transistor TR 21. Thus a TR 22 is turned on. Then the power supplies of 12V and 5V are supplied to a read/write IC 1. Thus the IC 1 can work. As a result, the signals (b) and (c) are surely set at high levels when the power is supplied to a power supply line 13 as long as the Zener voltage of the diode 26 is selected at an optional level. Thus it is possible to avoid the erasion of data on a medium regardless of the application sequence of power supply. |
