Miniature and efficient power supply adapter

The utility model discloses a miniature and efficient power supply adapter comprising a shell, which is characterized in that two metal pins are uniformly arranged on one surface of the shell, a USB (Universal Serial Bus) interface is arranged on the other surface of the shell, a PCB (Printed Circuit Board) board is arranged in the shell, the PCB board is electrically connected with the metal pins and the USB interface, respectively, a transformer is installed on the PCB board, the transformer comprises a transformer skeleton, a secondary coil, a primary coil and a magnetic core, the transformer skeleton comprises a hollow skeleton body, pins are arranged at the two ends of the skeleton body, the secondary coil, the primary coil and the magnetic core are sequentially arranged at the outside of the skeleton body from inside to outside, and the magnetic core is a ferrite magnetic core. The miniature and efficient power supply adapter disclosed by the utility model is small in size, high in efficiency, convenien