Patent ID: 8218279

Claim:
An electronic device for dynamic USB power assignment, comprising: a power circuit to convert external alternating current (AC) signals to driving voltage signals; a total current detection circuit to transmit the driving voltage signals to USB ports of the electronic device, and to detect whether a total current provided to the USB ports exceeds a rated total current, and output a total current detection signal if the total current exceeds the rated total current; a plurality of short-circuit detection circuits connected between the total current detection circuit and the plurality of USB ports respectively, to detect whether one or more USB devices connected to the corresponding USB ports are shorted and to output a short-circuit detection signal if the USB devices are shorted; a plurality of relay circuits correspondingly connected between the short-circuit detection circuits and the USB ports, to switch the connection between the USB ports and the power circuit on and off; and a USB controller connected to the total current detection circuit, the short-circuit detection circuits and the relay circuits, to output a control signal according to the total current detection signal and the short-circuit detection signal so as to control the relay circuits to switch the connection between the USB ports and the power circuit on and off.