| 摘要 |
PURPOSE: A circuit for controlling a power source for a computer is provided to boot a computer automatically by generating a power control signal in accordance with a power supply when a power source is supplied again after a computer is turned-off caused by a cut-off of a power as a power failure in a power supplying system adopting a power switch of an edge trigger method. CONSTITUTION: The first level shifter(201) and the second level shifter(202) adjust a signal level inputted from a power source(Vcc). An inverter(203a) inverts the outputting signal of the first level shifter(201). A flip-flop(203b) latches the outputting signal of the second level shifter(202). A NOR gate(203c) generates a remote control signal by logically processing the output signals of the inverter(203a) and the flip-flop(203b). A capacitor(204a) is connected to the input terminal of the second level shifter(202) and instantaneously charges an electric charge when the power source(Vcc) is supplied. A transistor(204b) is connected to the charged capacitor(204a) in parallel and controls the input signal of the second level shifter(202) by discharging the capacitor(204a). The first resistance(R1), the second resistance(R2) and the third resistance(R3) are connected to among the first level shifter(201), the second level shifter(202), the transistor(204b) and the power source(Vcc) for a stabilization of the input signals of the first level shifter(201), the second level shifter(202) and the transistor(204b).
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