| CPC H01F 38/14 (2013.01) [H02J 7/02 (2013.01); H02J 50/12 (2016.02); H02J 50/40 (2016.02)] | 17 Claims |

|
1. A method for operating a wireless charging device, comprising:
providing a charging current at a first frequency to a resonant circuit when the resonant circuit includes a first transmitting coil of the wireless charging device;
coupling a second transmitting coil of the wireless charging device to the resonant circuit;
determining an impedance of the resonant circuit after coupling the second transmitting coil to the resonant circuit;
providing the charging current at a second frequency to the resonant circuit based on the impedance of the resonant circuit after the second transmitting coil is coupled to the resonant circuit; and using a lookup table to determine the second frequency.
|