Apple Inc.
Wireless power control system

Abstract:

Wireless power transmitting equipment has a wireless power transmitter that includes a power converter and a radio-frequency inverter. The radio-frequency inverter may have an output coupled to a transmitting coil circuit formed from a capacitor coupled in series with a wireless power transmitting coil. Feedback information such as information on an output voltage from a rectifier in wireless power receiving equipment is wirelessly transmitted to the wireless power transmitting equipment. Signal phase and amplitude information such as the rectifier output voltage, current measurements in the wireless power receiver, and current and voltage phase and amplitude measurements made using a voltage sensor across the radio-frequency inverter output and a current sensor in series with the transmitting coil circuit may be used by the wireless power transmitting equipment to control the wireless power transmitter and thereby adjust wireless power transmission levels.