Wireless power system

摘要

A higher power wireless power transmitter (HPWPT) including a first, second and third circuit and a transmit coil for wirelessly powering a lower power wireless power receiver (LPWPR) is provided. The first circuit is a switch network. The second circuit is variable impedance network and/or a tuning network. The third circuit is a control logic circuit configured to change the input voltage source or topology of the first circuit, to change the impedance and/or tuning characteristics of the second circuit, to select the transmit coil, vary frequency or duty cycle of the PWM signal or any combination thereof. The change in the input voltage or topology of first circuit or change in impedance or tuning characteristics of second circuit or change in the transmit coil used or the applied constraints on the frequency and duty cycle of the PWM signal constrain the maximum power transmitted by the HPWPT to LPWPR.

主权项

1. A wireless power transmitter for powering a wireless power receiver, said wireless power transmitter comprising:
a first circuit that includes a switch network and configured to receive an input voltage; a second circuit connected between said first circuit and a transmitter coil, said second circuit configured to tune and deliver power to said transmitter coil; said transmitter coil configured to wirelessly transmit power to said wireless power receiver; and a third circuit that includes a control logic circuit, said third circuit configured to receive and decode messages from said wireless power receiver and configured to provide a variable frequency pulse width modulated signal to said first circuit and perform one or more of:
changing the said input voltage to the first circuit;driving of said first circuit to change a topology of said first circuit;driving of said second circuit to change second circuit's tuning characteristics and/or impedance offered;changing the said transmitter coil that is used to deliver power wirelessly to the said wireless power receiver; andconstraining the frequency and duty cycle of said pulse width modulated signal to a range of values and varying said frequency and said duty cycle of said pulse width modulated signal within those respective ranges; wherein, by said change in one or multiple of said input voltage, said topology of said first circuit, said tuning characteristics and/or impedance offered of said second circuit, said transmitter coil, said frequency of said pulse width modulated signal, and said duty cycle of said pulse width modulated signal, said wireless power transmitter is able to limit said transmitted power to said wireless power receiver.