Witricity Corporation

Qualcomm Incorporated

Marcel Fischer

Lukas Frank Sieber

Hanspeter Widmer

Hans Peter Widmer

Markus Bittner

Prasanth Venugopal

Mircea-Florian Vancu

Andreas Daetwyler

Nicholas Athol Keeling

Mickel Bipin Budhia

Leandro Percebon

Simon Islinger

Martin Pavlovsky

Stefan Raabe

Roman Bucher

Ning Liu

Patrick Lattmann

Rafal Scibor

Jonas Friedel

A method for detecting a foreign metal object near an inductive wireless power transfer system is based on combined inductive sensing and thermal sensing. A sensing system senses the object based on an inductive or thermal effect. The sensing system includes a sense element which has an electrical characteristic that changes in a presence of the object based on the inductive effect. A mediating heat-sensitive material has a property that varies as a function of temperature and changes the electrical characteristic of the sense element as the property changes. The mediating heat-sensitive material is heated by the foreign object when the foreign object is heated by a magnetic field generated by the wireless power transfer system. A controller measures the electrical characteristic and determines a presence of the object based on the change in the measured electrical characteristics.

Foreign object detection using combined inductive and thermal sensing

Systems and methods are described for active harmonics cancellation. A wireless charging apparatus includes a wireless-power transfer circuit comprising a wireless-power transfer coil configured to generate or couple to a magnetic field to transfer or receive power and a plurality of tuning capacitors electrically coupled to the wireless-power transfer coil. The apparatus also includes a power converter circuit electrically coupled to the wireless-power transfer circuit. Additionally, the apparatus includes a signal generation circuit different from the power converter circuit and electrically coupled to one or more nodes between capacitors of the plurality of tuning capacitors. The signal generation circuit is configured to generate and inject a signal into the wireless-power transfer circuit at the nodes between the capacitors. The signal generation circuit includes a rejection filter tuned to an operating frequency of the wireless-power transfer coil.

Active harmonics cancellation

This disclosure provides systems, methods and apparatus for detecting foreign objects. In one aspect an apparatus for detecting a presence of an object is provided. The apparatus includes a resonant circuit having a resonant frequency. The resonant circuit includes a sense circuit including an electrically conductive structure. The apparatus further includes a coupling circuit coupled to the sense circuit. The apparatus further includes a detection circuit coupled to the sense circuit via the coupling circuit. The detection circuit is configured to detect the presence of the object in response to detecting a difference between a measured characteristic that depends on a frequency at which the resonant circuit is resonating and a corresponding characteristic that depends on the resonant frequency of the resonant circuit. The coupling circuit is configured to reduce a variation of the resonant frequency by the detection circuit in the absence of the object.

Systems, methods, and apparatus for detection of metal objects in a predetermined space

This disclosure provides an apparatus for detecting a presence of an object in a predetermined area of an inductive wireless power transfer system. The apparatus comprises a first wire-wound structure having an electrical characteristic configured for electromagnetic sensing of the object. The first wire-wound structure is formed, carried, and held in place by a coil-former substantially from a non-conductive material. The coil-former also forms, carries, and holds in place a second wire-wound structure configured for transferring power inductively. The apparatus further comprises a detection circuit coupled to the first wire-wound structure and configured to measure the electrical characteristic of the first wire-wound structure and to detect the presence of the object in response to a change in the electrical characteristic.

Wire-wound structures for electromagnetic sensing of objects

Systems and methods are described for an extended-range positioning system based on foreign-object detection (FOD). In particular, a power-transfer apparatus is disclosed that includes a coil and a foreign-object-detection (FOD) system. The coil is configured to generate a magnetic field based on an electric current running through the coil for transferring power to a receiver device. the FOD system includes a plurality of FOD sense loops, FOD circuitry, and active-beacon receive circuitry. The FOD sense loops detect metal objects within the magnetic field based on changes to an electrical characteristic(s) of one or more of the FOD sense loops. The FOD circuitry processes a modulation pattern of the electrical characteristic(s) of the one or more FOD sense loops and provides first positioning information. The active-beacon receive circuitry processes induced voltage in at least two sense loops to provide second positioning information.

Extended-range positioning system based on foreign-object detection

The present disclosure describes aspects of ripple current reduction for wireless electric vehicle charging. In some aspects, an apparatus for wireless power transmission includes an inverter circuit to provide alternating current and a resonant circuit having a tuning portion and a coil portion to transmit power based on the alternating current. The apparatus also includes a current sensor to provide an indication of peak-to-peak amplitude (e.g., ripple current) of the alternating current that flows to the coil portion of the resonant circuit. Based on this indication, a control signal of the inverter is altered to adjust the peak-to-peak amplitude of the alternating current, such as to reduce ripple current in the coil portion. By so doing, ripple current can be reduced in power-transmitting or power-receiving devices, which may improve power transmission efficiency, enable use of smaller decoupling capacitors, or reduce stress on elements of respective resonant circuits.

Ripple current reduction for wireless electric vehicle charging

One aspect of the disclosure provides an apparatus for conveying wireless power. The apparatus comprises a circuit board disposed along one or more planar coils and a plurality of feeds. The circuit board is divided into a first area separate from a second area. The first area has a plurality of first voltage components and the second area has a plurality of second voltage components. The first voltage components operates at a lower voltage than the second voltage components. The plurality of feeds are coupled to the one or more planar coils and the circuit board. The plurality of feeds pass through the circuit board within the second area along a side of the circuit board and couple to one or more of the second voltage components.

System and method for reducing interference in a wireless power transfer system

An apparatus for wirelessly receiving power from a wireless power transmitter is provided. The apparatus comprises an active switching rectifier operably connected to a coupler and configured to operate in a first bridge mode and a second bridge mode. The apparatus comprises a controller configured to adjust an input resistance of the rectifier to a first value that provides a first wireless power transfer efficiency when the rectifier operates in the first bridge mode. The controller is configured to adjust the input resistance of the rectifier to a second value that provides a second wireless power transfer efficiency less than the first wireless power transfer efficiency while operating within one or more operating limitations when the rectifier operates in the second bridge mode.

Systems, apparatus and method for adaptive wireless power transfer

An apparatus for detecting a presence of an object can include a plurality of electrically conductive loops arranged in an array. The apparatus includes a sensor circuit configured to determine a characteristic associated with each of the plurality of loops. The apparatus includes a hardware processor configured to, for each loop of the plurality of loops, determine a parameter based on the characteristic associated with the loop and the characteristic associated with at least one adjacent loop. The hardware processor may be further configured to determine the presence of the object based on the parameter. The parameter may comprise a sum of a difference between the characteristic associated with the loop and a reference value for the characteristic, and a difference between the characteristic associated with each of the at least one adjacent loop and the reference value.

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Boniswil, Switzerland

Marcel Fischer