Abstract: A primary resonant network for a wireless power transfer has a primary winding capable of being energized to provide a magnetic field, and a reactive component selected to constrain the reactive loading on a power supply which energizes the primary resonant network. The reactive component is selected dependent on a given variation in inductance or capacitance of the primary resonant network and a given variation in inductance or capacitance of a secondary resonant network coupled to the primary resonant network.

Abstract: In certain aspects, methods and systems for controlling power transfer at a wireless power receiver are disclosed. In certain aspects, a method includes determining a duty cycle of a DC-DC converter of the wireless power receiver. The method further includes determining a duty cycle limit for an AC switching controller based on the determined duty cycle. The method further includes determining an operational duty cycle for the AC switching controller. The method further includes comparing the operational duty cycle to the duty cycle limit. The method further includes adjusting at least one of a desired voltage and current input to the DC-DC converter when the operational duty cycle is greater than the duty cycle limit.

Abstract: Certain aspects of the present disclosure are generally directed to apparatus and techniques for wirelessly charging a device. An exemplary method generally includes receiving, at a first wireless power transfer device, a synchronization signal indicative of a phase for generating a wireless charging field, determining an adjusted phase for generating the wireless charging field based, at least in part, on the received synchronization signal and one or more measurements taken at least one of the first wireless power transfer device or a second wireless power transfer device, wherein the one or more measurements are indicative of a phase difference between the first wireless power transfer device and the second wireless power transfer device, and generating, at the first wireless power transfer device, the wireless charging field with the adjusted phase.

Abstract: An inductive power transfer (IPT) control method is disclosed for controlling the output of an IPT pick-up. The invention involves selectively shunting first and second diodes of a diode bridge to selectively rectify an AC current input for supply to a load, or recirculate the AC current to a resonant circuit coupled to the input of the controller. By controlling the proportion of each positive-negative cycle of the AC input which is rectified/recirculated, the output is regulated. Also disclosed is an IPT controller adapted to perform the method, an IPT pick-up incorporating the IPT controller, and an IPT system incorporating at least one such IPT pick-up.

Abstract: Certain aspects of the present disclosure are generally directed to apparatus and techniques for apparatus for wireless charging. The apparatus generally includes a first wireless charging element, and transmit circuitry coupled to the first wireless charging element and configured to supply power to the first wireless charging element to transmit a wireless charging field to a vehicle. In certain aspects, the apparatus also includes a controller coupled to the transmit circuitry and configured to determine a charging condition indicative of a speed of the vehicle, and adjust the power supplied to the first wireless charging element via the transmit circuitry based on the determination.

Abstract: The present disclosure describes aspects of a vehicle-based beacon mode for wireless electric vehicle charging. In some aspects, a circuit for receiving wirelessly transferred power includes a coil connected to boost circuitry configured to convert received power to a form suitable for storage. The circuit also includes beacon circuitry connected to a voltage source that, in combination with portions of the boost circuitry, enables current to be driven into the coil to generate a beacon signal. Based on this beacon signal, a base charging unit can detect the presence of the circuit and initiate the wireless transmission of power to the circuit without additional out-of-band communication. Further, the beacon circuitry may be compatible with, or protected from, current of the received power such that the circuit can seamlessly transition from generating the beacon signal to converting the received power without active reconfiguration, synchronization, or state control.

Abstract: Systems and methods are described that increase pad efficiency and robustness. These systems and methods balance magnetic flux density in ferrite strips in a WEVC pad to reduce heat produced in high-flux areas of the ferrite strips. Aspects include controlled spacing between ferrite strips of a WEVC pad and intentional gaps located within high-flux areas in the strips. The sizes of the intentional gaps are determined in relation to the size of the spacing between the strips. In addition, ribs are disposed between the strips and connected to a backplate to provide structural rigidity and robustness to the pad.

Abstract: One aspect provides a wireless power transmitter. The wireless power transmitter includes a transmit antenna configured to generate a field for wireless transmit power in both a first and second configuration. The wireless power transmitter further includes a first capacitor. The wireless power transmitter further includes at least one switch configured to selectively connect the first capacitor in one of the first and second configuration, the first capacitor being in parallel with the transmit antenna in the first configuration and in series with the transmit antenna in the second configuration. The wireless power transmitter further includes a second capacitor in parallel with the transmit antenna and a transformer configured to operate at a first turns-ratio in the first configuration and a second turns-ratio in the second configuration, the first turns-ratio being lower than the second turns-ratio.

Abstract: An apparatus for wirelessly transferring power is provided. The apparatus comprises a first coupler, a second coupler, and a third coupler overlapping at least the first coupler. The apparatus further comprises a ferrimagnetic structure comprising a first portion disposed under the first coupler, a second portion disposed under the second coupler, and a gap defined between the first coupler and the second coupler, the gap physically separating the first portion from the second portion. One or both of the first portion and the second portion comprises a first plurality of ferrimagnetic strips interleaved with a second plurality of ferrimagnetic strips configured to attenuate a magnetic flux passing between the first and second couplers. The first plurality of ferrimagnetic strips are interleaved with the second plurality of ferrimagnetic strips under at least a portion of the first coupler that is overlapped by the third coupler.

Abstract: Systems, methods, and apparatus are disclosed for power transfer including a plurality of coil structures located over a ferrite element, the plurality of coil structures configured to generate a high flux region and a low flux region, the low flux region being located between the plurality of coil structures, and a tuning capacitance located directly over the ferrite element in the low flux region.

Abstract: An inductive power transfer (IPT) control method is disclosed for controlling the output of an IPT pick-up. The invention involves selectively shunting first and second diodes of a diode bridge to selectively rectify an AC current input for supply to a load, or recirculate the AC current to a resonant circuit coupled to the input of the controller. By controlling the proportion of each positive-negative cycle of the AC input which is rectified/recirculated, the output is regulated. Also disclosed is an IPT controller adapted to perform the method, an IPT pick-up incorporating the IPT controller, and an IPT system incorporating at least one such IPT pick-up.

Abstract: Systems, methods and apparatus for wireless power transfer and particularly wireless power transfer to remote systems such as electric vehicles are disclosed. In one aspect an induction coil is provided comprising a plurality of substantially co-planar coils formed from one or more lengths of conducting material, each length of conducting material being electrically connectable at each end to a power source or battery, and wherein at least one of the lengths of conducting material is continuously wound around two or more of the coils. In another aspect, a method is provided for forming such an induction coil. In yet another aspect, a switching device is operable to alter the configuration of the coils, for example in response to a detected characteristic of another induction coil or device coupled thereto.

Abstract: Systems, methods, and apparatuses utilizing a bipolar double D vehicle coupler in wireless power transfer applications are described herein. Some implementations may include an apparatus for wireless power transfer. The apparatus comprises a first coil and a second coil connected in series to form a first circuit. The first coil does not overlap the second coil. The apparatus comprises a third coil and a fourth coil electrically connected in series to form a second circuit. The third coil does not overlap the fourth coil. At least a portion of the first circuit overlaps at least a portion of the second circuit. The first circuit is substantially magnetically decoupled from the second circuit.

Abstract: Techniques for wirelessly transferring energy to a vehicle are disclosed. An example method for wirelessly transferring energy to a vehicle according to the disclosure includes detecting a ripple frequency on a transmitter coil circuit, such that the ripple frequency is associated with a vehicle switch mode controller frequency of a switch mode controller in the vehicle, and providing an electrical current to a coil in the transmitter coil circuit based at least in part on the ripple frequency.

Abstract: According to some implementations, an apparatus for transmitting charging power wirelessly to a load is provided. The apparatus comprises at least one ferrite structure comprising a first ferrite portion, a second ferrite portion comprising at least a first ferrite leg, a second ferrite leg, and a third ferrite leg, each physically separated from the first ferrite portion by a first distance, and a third ferrite portion positioned between the second ferrite leg and the first ferrite portion and physically contacting the second ferrite leg. The at least one ferrite structure further comprises a coil wound around the second ferrite leg and configured to generate an alternating current under influence of an alternating magnetic field.

Abstract: Aspects of this disclosure include an apparatus configured to and methods for the transfer of wireless power. The apparatus comprises a first coil enclosing a first area. The apparatus also comprises a second coil enclosing a second area different than the first area, the second coil positioned to be at least partially coplanar with the first coil. The apparatus further comprises a ferrite material and a third coil and a fourth coil each wound about the ferrite material, the third coil at least partially enclosed by the first coil and the fourth coil at least partially enclosed by the second coil.

Abstract: Systems and methods in accordance with particular embodiments provide for alignment of an electric vehicle induction coil with a base system induction coil through a determination of the phase of a base system induction coil current signal. In certain embodiments, an electric vehicle induction coil that receives a transmission signal can be determined to be in greater alignment with a base system induction coil that transmits the transmission signal as the phases of the current signals at the base system induction coil and the electric vehicle induction coil converge. One embodiment includes a method of receiving wireless power, including detecting a transmission signal in a wireless power transmission, the transmission signal comprising periodic variations between a first frequency and a second frequency. The method further includes determining a phase of a base system induction coil signal based on the detected transmission signal.

Abstract: Systems, methods, and apparatus for partial electronics integration in vehicle pads for wireless power transfer applications are provided. In one aspect, an apparatus for wirelessly receiving charging power is provided. The apparatus comprises a first enclosure including at least a receive coupler configured to generate an alternating current under the influence of an alternating magnetic field in a first enclosure. The first enclosure further includes a rectifier circuit configured to modify the alternating current to produce a direct current for output from the first enclosure to a controller circuit in a disparately located second enclosure. The apparatus further comprises at least one direct current inductor configured to receive the direct current from the rectifier circuit. In some implementations, the apparatus further comprises the controller circuit in the second enclosure. The controller circuit is configured to selectively provide the direct current to a battery.

Abstract: An integrated circuit (IC) design method includes receiving a spatial correlation matrix, R, of certain property of post-fabrication IC devices; and deriving a random number generation function g(x, y) such that random numbers for a device at a coordinate (x, y) can be generated by g(x, y) independent of other devices, and all pairs of random numbers satisfy the spatial correlation matrix R. The method further includes receiving an IC design layout having pre-fabrication IC devices, each of the pre-fabrication IC devices having a coordinate and a first value of the property. The method further includes generating random numbers using the coordinates of the pre-fabrication IC devices and the function g(x, y); deriving second values of the property by applying the random numbers to the first values; and providing the second values to an IC simulation tool.

Abstract: An apparatus for wirelessly transferring power to a receive coupler is provided. The apparatus comprises a first coupler connected to a second coupler. The apparatus further comprises a third coupler overlapping the first and second couplers. The apparatus further comprises a controller configured to receive power from at least one power supply, provide a first current to the first coupler and the second coupler in a first charging mode, and provide the first current to the first coupler and the second coupler and provide a second current to the third coupler in a second charging mode. A magnetic flux generated by the first current passing through a first portion is constructively additive with a magnetic flux generated by the first current passing through a second portion.