WIRELESS POWER TRANSFER SYSTEMS FOR SURFACES
The disclosure features wireless energy transfer sources that include at least two source resonators and a power source, where: each of the at least two source resonators has a nominal impedance when a device resonator is not positioned on or near any of the at least two source resonators, the nominal impedances of each of the at least two source resonators varying by 10% or less from one another; and the at least two source resonators are configured so that during operation of the wireless energy transfer source, when a device resonator is positioned on or near a first one of the at least two source resonators: (a) the impedance of the first source resonator is reduced to a value smaller than the nominal impedances of each of the other resonators by a factor of 2 or more.
1 . A wireless energy transfer source, comprising:
at least two source resonators electrically connected in parallel and configured so that during operation, the at least two source resonators can each transfer energy wirelessly via an oscillating magnetic field to a device resonator; and
a power source coupled to a first tunable element and to each of the at least two source resonators, and configured so that during operation, the power source provides a supply of electrical current,
wherein each of the at least two source resonators has a nominal impedance when a device resonator is not positioned on or near any of the at least two source resonators, the nominal impedances of each of the at least two source resonators varying by 10% or less from one another; and
wherein the at least two source resonators are configured so that during operation of the wireless energy transfer source, when a device resonator is positioned on or near a first one of the at least two source resonators:
the impedance of the first source resonator is reduced such that the reduced impedance of the first source resonator is smaller than the nominal impedances of each of the other resonators by a factor of 2 or more; and
the first source resonator draws electrical current from the power source.