A wall socket includes a socket housing, an output terminal, a power converter circuit and a load detection circuit. The output terminal is arranged at a side of the socket housing and configured to output a DC output voltage. The power converter circuit is arranged in the socket housing and configured to convert an input voltage to the DC output voltage according to a control signal. The load detection circuit is configured to receive an identification signal outputted by an electronic device when the electronic device is connected to the output terminal, and output the control signal according to the identification signal to adjust a voltage level of the DC output voltage.