Feedback control schemes for wireless power transfer circuits

Portable electronic devices such as cellular telephones, wristwatch devices, tablet computers, wireless earbuds, and other portable devices use batteries. The batteries in these devices may be charged using a wireless power system. For example, a user may place devices such as tablet computers and cellular telephones on a wireless charging puck or mat to wirelessly charge these devices. Wireless power systems include a power transmitting device and a power receiving device. Coils in the power transmitting and receiving devices are used to transmit and receive wireless power signals. The coupling between the transmitting and receiving coils may affect the wireless charging efficiency and the power produced in the receiving device. Disclosed herein are feedback control schemes to optimize efficiency of wireless power transfer systems. POWER TRANSMITTING POWER RECEIVING DEVICE DEVICE BAT TERY 58 AC-DC [K14 BATTERY II i/O DEVICES CONTROL 16 _________H CONTROL CIRCUITRY 30 TX RX MEA SUREMENT -41 CIRCUITRY TX/RX46 POWER TRANSMfI'TING .. MEASUREMENT --- 43 CIRCUITRY 5 2 CIRCUITRY 42- COILSRCUTR POWER RECEIVING 54 I TER CIRCUITRY 44 COI RECTIFIER