A method of transferring wireless power using magnetic induction, can include selecting a coil among a plurality of coils partially overlapping each other; sensing a current flowing through the selected coil; receiving an amount of power requested by a wireless power receiver; and controlling an output voltage of a DC-DC converter based on the current flowing through the selected coil and the amount of power requested by the wireless power receiver, in which the controlling the output voltage of the DC-DC converter includes: dividing the output voltage of the DC-DC converter to generate a divided output voltage; and adjusting a level of the output voltage of the DC-DC converter with a feedback signal based on the divided output voltage, in which the dividing the output voltage includes damping the output voltage by a first resistor, a second resistor and a third resistor, and the first resistor is connected between an output terminal of the DC-DC converter and a feedback port of the DC-DC converter, the second resistor is connected between the feedback port of the DC-DC converter and ground, and the third resistor is connected between a controller and the feedback port of the DC-DC converter.