Adapters, terminal devices, USB connection devices and charging stations are disclosed. The adapter includes a first port configured to connect to an alternate current (AC) source, a conversion module configured to convert an AC power from the AC source into a direct current (DC) power, a second port configured to connect to a first electronic device and provide power thereto, an uplink interface configured to connect to the first electronic device, a downlink interface coupled with the conversion module to obtain an external power supply therefrom and configured to connect to a second electronic device, and a signal control module arranged between the uplink and downlink interfaces, and configured to control a status of a signal in the downlink interface based on a status of a power supply of the uplink interface. The second electronic device enters one of the operating and charging modes based on the status of the signal in the downlink interface, when the second electronic device is coupled with the downlink interface. With the present invention, charging of an electronic device which can be charged only upon recognizing the signal line status of the downlink interface can be enabled even if a computer is powered off or in a sleep state.