| 摘要 |
PURPOSE:To improve economy without reducing reliability by providing only one present use power source for a plurality of power receivers. CONSTITUTION:Since power sources 6-0, 7-0, 8-0 supply higher voltage than that of a power source 12 in a normal power supply state, powers are supplied through diodes 9-0, 10-0, 11-0 to an input/output unit 2, a memory 3, a main clock unit, and no power is supplied from a preliminary power source. If the power source 6-0 now stops supplying power so that the supplying voltage becomes zero, a forward voltage is applied to the diode 13 of a power supply passage to the unit 2 from a power source 12 to set it to a conductive state, and it is continuously supplied from the power source 12. The power source 12 has power supplying capacity of the power or more of the power source 6-0, the supplying voltage is set to an allowable value capable of operating the input unit 2, thereby supplying the power without defect. When the other power source stops supplying the power, the power is continuously supplied similarly without defect. |
