Apple Inc.
Wireless Power System With Device Priority

Abstract:

A wireless power system may have a wireless power transmitting device and wireless power receiving devices. The wireless power transmitting device has wireless power transmitting circuitry with coils to transmit wireless power to wireless power receiving devices. The wireless power receiving devices are placed on the wireless power transmitting device in an order. Batteries in the wireless power receiving devices are charged based at least partly on the order. Power allocation is based on utilization factor information such as information on a power draw associated with each of the power receiving devices. Measurement circuitry in the wireless power transmitting device is used to gather impedance images from the coils. Changes in the impedance images are used to temporarily halt power transmission. Power transmission is resumed depending on whether in-band communications are lost or are maintained.