Patent ID: 8433943
Filing Date: 2013-04-30
Classification: G06F

Abstract:
1. A power-supply expansion system comprising: a primary power-supply unit providing a main power supply; a secondary power-supply unit providing an auxiliary power supply; a power unit comprising a first input terminal, a second input terminal, and an output terminal; the first input terminal receiving the main power supply or the auxiliary power supply, the second input terminal receiving the auxiliary power supply, the power unit integrating the main power supply and the auxiliary power supply into an output power supply, and the output power supply fed to a load terminal via the output terminal; and a control unit being connected to the primary power-supply unit and the secondary power-supply unit; and the control unit, based on a load value of the primary power-supply unit, selectively performing a power-supply expansion process so as to feed the auxiliary power supply to the second input terminal by the secondary power-supply unit; an overcurrent protection unit electrically connected to the secondary power-supply unit; and the overcurrent protection unit limiting the auxiliary power supply provided by the secondary power-supply unit to a value not exceeding a nominal current value; a first switch being located between the overcurrent protection unit and the first input terminal, and being selectively turned on or turn off according to a switch control signal output by the control unit; and a second switch being located between the overcurrent protection unit and the second input terminal, and being selectively turned on or turn off according to the switch control signal output by the control unit; wherein when the control unit determines the load value reaches a first preset value, the control unit turns off the first switch and turns on the second switch to perform the power-supply expansion process; wherein when the control unit determines the load value is smaller than a second preset value in a preset time span, the control unit turns off the second switch and turns on the first switch to stop performing the power-supply expansion process; wherein the power-supply expansion system further comprises a charging control unit being electrically connected to the primary power-supply unit, the secondary power-supply unit and the control unit, and when the control unit determines the load value is smaller than a third preset value in the preset time span, the charging control unit controlled by a second control signal generated by the control unit to perform a charge action to the secondary power-supply unit; wherein when the control unit determines the load value is smaller than a fourth preset value, the control unit stops performing the power-supply expansion process and supplies the auxiliary power supply via the first switch by the control unit.