Patent ID: 7928776

Claim:
A voltage detection device for a computer, comprising: a comparator circuit comprising a first input terminal and a second input terminal connected to a system power supply and a standby power supply respectively, and an output terminal capable of outputting a high or low voltage according to the comparison result; a switch circuit comprising a control terminal to receive the voltage output from the comparator circuit, a power terminal to receive the standby power supply, and a ground terminal grounded; and an indicator circuit connected to the switch circuit; wherein upon a condition that the voltage of the system power supply is lower than its standard voltage range, the voltage of the standby power supply is within its standard voltage range, and the computer is on, the comparator circuit outputs a high voltage, the switch circuit is turned on, the indicator circuit indicates an abnormal state; upon a condition that the voltage of the standby power supply is lower than its standard voltage range, the voltage of the system power supply is within its standard voltage range, and the computer is on, the comparator circuit outputs a low voltage, the switch circuit is turned off, the indicator circuit indicates an abnormal state; and upon a condition that the voltage of the standby power supply is lower than its standard voltage range, the voltage of the system power supply is within its standard voltage range, and the computer is off; the comparator circuit does not work, the switch circuit is off, and the indicator circuit indicates an abnormal state.