Mixer with wireless power transmission

A mixer, comprising:

• a revolution device having a revolution base to be driven for rotation;
• a first spin device connected to the revolution base of the revolution device;
• a first barrel connected to the first spin device to be spun by the first spin device;
• a transmitting coil electrically connected to a power source to generate a time-vary magnetic field;
• a receiving coil connected to the revolution base of the revolution device and electrically connected to the first spin device, wherein the receiving coil rotates with the revolution base;
• wherein the receiving coil receives the time-vary magnetic field of the transmitting coil and produces an electromotive force to be supplied to the first spin device
• a board, wherein the revolution device is connected to the board, and the first spin device, the transmitting coil, the receiving coil, and the first barrel are located at a side of the board;
• a box, in which the board is provided to divide a space in the box into a first space and a second space, wherein the revolution base, the first spin device, the receiving coil, and the first barrel are received in the second space;
• a vacuum device for removing gas out of the second space;
• and
• a lid connected to the revolution base in an airtight condition, wherein the transmitting coil is received in the lid, and the receiving coil is connected to an outer surface of the lid.