US Patent 10084343 Frequency changing encoded resonant power transfer

Systems and methods to for wireless power transfer are provided. A transmit control module generates a sequence of resonant drive frequencies for a transmit coil. The transmit control module adjusts the resonant frequency of the transmit coil according to the sequence of resonant drive frequencies. A receive control module provides payment verification to the transmit control module and receives the sequence of resonant drive frequencies from the transmit control module in return. The receive control module adjusts a resonant frequency of a receive coil according to the sequence of resonant drive frequencies to match the resonant frequency of the transmit coil. The resonant frequencies of the transmit and receive coils change at the same time to maintain coupling and efficient power transfer.