WIRELESS POWER AND VOLTAGE REGULATION FOR WIRELESS POWER TRANSFER SYSTEMS

A variety of applications can include wireless power and voltage regulation for wireless power transfer systems. A receiver can receive power wirelessly from a transmitter to provide an output voltage. The receiver can regulate the output voltage with respect to a window defining an upper threshold and a lower threshold and can generate a first signal in response to the output voltage exceeding the upper threshold voltage and a second signal in response to the output voltage reducing below the lower threshold voltage. The receiver can change its input impedance and control reception of the power in response to the first and second signals. A transmitter can sense current in the power transistors or the coil of the transmitter in response to the change of input impedance of the receiver. The sensed current can be used to modify the current to the output of the transmitter to adjust the transmitted power.