Abstract: A power supply includes a power supply module, a microcontroller, a setting unit, a number of switch units, a number of current detection units, and a number of output connectors. Each switch unit is connected to one output connector via one current detection unit. The power supply module converts an alternating current (AC) voltage into a direct current (DC) to power electronic devices connected to each output connector by the corresponding switch unit, and the corresponding current detection unit. Each current detection unit detects a current passing through the output connector. The microcontroller calculates a total power of the power supply module according the detected currents and the DC voltage, and turns off all the switch units when the total power is greater than a predetermined current according to a protection mode set in the setting unit.

Abstract: An electronic device includes a detection module, an identification code generation module, a decryption module, a comparison module, and a control module. The detection module transmits a detection signal after detecting that a power adapter is connected to the electronic device. The identification code generation module randomly generates an encrypted identification code after receiving the detection signal. The decryption module decrypts the identification code to generate a first decryption code. The comparison module compares a second decryption code that has been fed back from the power adapter after the power adapter receiving the detection signal, with the first decryption code. The control module controls the electronic device to receive power from the power adapter when the first decryption code is the same as the second decryption code.