Abstract: A power providing apparatus includes a first input port for connection to a first electricity source, a second input port for connection to a second electricity source, an output port, a first current control component connected between the first input port and the output port, and a second current control component connected between the second input port and the output port. Based on voltages associated with the first electricity source and the second electricity source, each of the first and the second current control components makes or breaks a current path from a respective one of the first and second input ports to the output port.