Patent ID: 8395520
Filing Date: 2013-03-12
Classification: G06F

Abstract:
1. A device for monitoring a voltage of a motherboard, the device comprising: a first monitoring circuit outputting a first voltage in response to the voltage of the motherboard being higher than an upper limit voltage; a second monitoring circuit outputting the first voltage in response to the voltage of the motherboard being lower than a lower limit voltage; a voltage reduction circuit reducing the first voltage; and an indicating circuit indicating the voltage of the motherboard being abnormal in response to receipt of the reduced first voltage, wherein the first monitoring circuit comprises a first voltage divider receiving the voltage of the motherboard, and outputting a divided voltage, the first monitoring circuit further comprises a first comparator, a first electric switch, and a first light emitting diode (LED), the second monitoring circuit comprises a second comparator, a second electric switch, and a second LED; the first comparator compares the divided voltage with a first reference voltage, and outputs a first control signal, the second comparator compares the divided voltage with a second reference voltage, and outputs a second control signal; the first electric switch comprises a first terminal receiving the first control signal, a grounded second terminal, and a third terminal receiving a working voltage via a first resistor, the second electric switch comprises a first terminal receiving the second control signal, a grounded second terminal, and a third terminal receiving the working voltage via a second resistor; a cathode of the first LED is connected to the third terminal of the first electric switch, an anode of the first LED receives the working voltage via a third resistor, a cathode of the second LED is connected to the third terminal of the second electric switch, an anode of the second LED is connected to the anode of the first LED, a node between the anodes of the first and second LEDs outputs the first voltage in response to the divided voltage being higher than the first reference voltage or lower than the second reference voltage, the first LED emits light in response to the divided voltage being higher than first reference voltage, the second LED emits light in response to the divided voltage being lower than the second reference voltage.