Power-supply voltage stabilized MP3 player and USB power-supply change-over integrater for automobile

The utility model relates to a power supply voltage regulation device for vehicle, specially an integration device with power supply voltage regulation, MP3 playing and USB power transfer. The device is electrical connected with a power supply output end of the vehicle and comprises a main body of power supply voltage regulation and transfer device, the device has a circuit main board arranged in a metal or plastic shell. The innovative points is: the circuit main board comprises a power supply voltage regulation unit, a USB power transfer unit and a MP3 playing unit, and a front panel of the metal or plastic shell is arranged with a memory card reader socket, an USB interface socket, a display module and a cigar lighter socket. The utility model integrates functions of power supply, MP3 playing and USB power transfer to be a unit without changing the original consumer automobile engine, oil circuit system and circuit system structure, which can be widely used in various vehicle types.