Abstract: A structure for providing power to external mobile devices has a first power supply module and a second power supply module. The first power supply module has a first voltage source outputting an activation current to a main circuit of an external mobile device when activated. The second power supply module has a first boost circuit and an activation circuit. A second voltage source from a computer supplies power to the first boost circuit through the first boost circuit to output a first operating current to the main circuit through the activation circuit to replace the activation current supplied from the first power supply module. The structure further has a blocking circuit blocking the first voltage source to keep supplying power for the purpose of energy conservation and carbon reduction when the external mobile device is powered off.

Abstract: A driving system and a driving method for a portable 3.5 inch external hard disk are disclosed. The driving system includes a first power supply module, a second power supply module and the portable 3.5 inch external hard disk. The first power supply module installed in the portable 3.5 inch external hard disk includes a first voltage source having a first output voltage supplies power to a main circuit. The second power supply module includes a second voltage source outputting a first voltage and a second voltage through a first interface output port and a second interface output port, respectively, which are combined to form a second output voltage to supply power to a boost circuit. The boost circuit then outputs a working current to provide to a start circuit, which replaces the first power supply module and hence maintains operation of the external hard disk.