Power supply system for motherboard

A power supply system for a motherboard, comprising:

• a voltage regulator circuit comprising a system power source, and a voltage output terminal, the voltage output terminal outputting a predetermined stable voltage provided by the system power source or a voltage of the system power source;
• a sampling circuit having an input, and an output, the input of the sampling circuit receiving the voltage output from the voltage regulator circuit, the output of the sampling circuit receiving a high level sleep signal from a south bridge of the motherboard;
• a switching circuit having an input, and an output, the input of the switching circuit being connected to the output of the sampling circuit;
• a power connector having a control terminal connected to the output of the switching circuit;
• and
• a power source being connected to the power connector;
• when the sampling circuit receives the stable voltage from the voltage regulator circuit, the sampling circuit has no signal output at the output, the switching circuit receives the high level sleep signal from the south bridge and outputs a low level signal to the control terminal of the power connector to make the power source provide power to the motherboard normally;
• when the sampling circuit receives the voltage of the system power source from the voltage regulator circuit, the sampling circuit outputs a low level signal, the switching circuit receives the low level signal from the sampling circuit and outputs a high level signal to the control terminal of the power connector to make the power source shut off the system power source of the voltage regulator circuit.

A power supply system for a motherboard, comprising:

• a voltage regulator circuit connected to a system power source of the motherboard, the voltage regulator circuit comprising a voltage output terminal for outputting a predetermined stable voltage, when the voltage regulator circuit works normally, to electronic components mounted on the motherboard;
• a sampling circuit comprising an input connected to the output terminal of the voltage regulator circuit, and an output;
• a switching circuit comprising an input connected to the output of the sampling circuit;
• a power connector comprising a control terminal connected to the output of the switching circuit;
• and
• a power source connected to the power connector configured to provide power to the motherboard via the power connector;
• wherein
• when the output terminal of the voltage regulator circuit outputs a voltage greater than the predetermined stable voltage to the sampling circuit, the sampling circuit outputs a low level signal to the switching circuit which in return outputs a high level signal to the control terminal of the power connector to cut off power supply from the power source to the system power source.