POWER ADAPTER, AND CHARGING SYSTEM AND METHOD

The present application relates to the technical field of communications, and provides a power adapter, and a charging system and method, which are simple in structure and low in cost. The power adapter comprises a control module, a conversion module, a power adjustment module and at least one charging port. The power adjustment module comprises N switch transistors. A control end of the conversion module and control ends of the N switch transistors are electrically connected to the control module. An output end of the conversion module is electrically connected to first ends of the N switch transistors. Second ends of the N switch transistors are electrically connected to the charging port. The control module receives at least one voltage to be charged and current to be charged, and an output voltage of the conversion module is determined according to said voltage and current. The conversion module receives a first control signal sent by the control module, converts, into an output voltage, an alternating vo