POWER SOURCE SELECTION CONTROL

A system and method for power source selection control. Multiple power sources of a power supply unit are each connected to a high power load via a plurality of switching circuitries each comprising at least one pair of transistors connected in a common source configuration and positioned between a positive lead of a respective one of the power sources and the high power load. A controller detects presence of a current flow from at least one of the power sources and accordingly selects one of power sources and activates a respective one of the plurality of switching circuitries for conducting a current flow from the respective power source selected to the high power load.