Frequency changing encoded resonant power transfer

Abstract

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.

What is claimed is: 
     
         1 . A system to provide wireless power transfer to one or more mobile devices, the system comprising:
 a transmit coil that is configured to generate an electromagnetic signal that induces a current in one or more receive coils of the one or more mobile devices effective to provide power to the one or more mobile devices; and   a control module that is communicatively coupled to the transmit coil and to the one or more mobile devices, the control module configured to generate a sequence of resonant drive frequencies and to adjust a resonant drive frequency of the transmit coil in accordance with the generated sequence of resonant drive frequencies,   the control module further configured to provide the sequence of resonant drive frequencies to the one or more mobile devices effective to allow the one or more receive coils of the one or more mobile devices to be driven by substantially the same resonant drive frequency as the transmit coil.