Abstract: A Power over Ethernet (PoE) system and method that can provide greater power efficiency and reduces greenhouse gas emissions is described. The PoE system includes power supply equipment, Ethernet cabling, and a powered device. When a load is not present at the end of the Ethernet cabling, an injector in the power supply equipment enters a sleep state, thus conserving power and increasing efficiency. When the injector is electrically connected to a load, such as the powered device, a circuit in the injector activates power to a digital control logic and subsequently provides power to a sensing conductor in the Ethernet cable, thereby enabling high efficiency power transfer.

Abstract: A device can be used to convert power supplied by an external power source into power that is compatible with an external electronic device. In an example implementation, the device receives direct current (DC) power from the external power source through a USB connection interface, converts it into DC power of a different voltage, and outputs the converted power to the external electronic device.