Abstract: Systems and methods are described that reduce magnetic flux density proximate to a wireless charging pad, such as a WEVC pad. These systems and methods control peak magnetic flux density in air around a WEVC pad to reduce potentially dangerous heat produced in foreign metal objects affected by a magnetic field generated by a coil of the WEVC pad. Controlling the peak magnetic flux density results in a safer WEVC pad. Aspects include ferrite tiles being separated by gaps having predefined sizes to increase a magnetic reluctance of a path of the magnetic flux through the ferrite tiles, which reduces a peak magnetic flux density experienced in areas proximate to the coil. In addition, the ferrite tiles can be arranged such that a combination of gaps are aligned with a region overlapping the coil.

Abstract: In an aspect of the disclosure, an apparatus for wirelessly transmitting power is provided. The apparatus includes a communication circuit configured to communicate with a first wireless power transmitter and a second wireless power transmitter. The apparatus further includes a controller circuit configured to identify a first phase of a first current provided to the first wireless power transmitter, the first current generating a first magnetic field. The controller circuit further determines a time to provide a second current to the second wireless power transmitter. The controller circuit further provides the second current at the determined time with a second phase having a phase difference between the first phase configured to reduce a magnitude of a combined magnetic field of the first and second magnetic fields in a region between the first and second wireless power transmitters.

Abstract: In certain aspects, methods and systems for reducing magnetic field emissions from double-D inductive couplers are disclosed. Certain aspects of the present disclosure provide a power transfer device for reducing magnetic field emissions. The power transfer device generally includes a first coil and a second coil configured to generate a charging field; and at least one auxiliary coil coupled in series with at least one of the first coil or the second coil, the at least one auxiliary coil being configured to reduce magnetic field emission of the charging field.

Abstract: 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.

Abstract: Techniques for detecting a presence of a foreign object within a region for wirelessly transferring power to charge an electric vehicle are discloses. An example apparatus according to the disclosure includes a foreign object detection (FOD) structure including a transmitting loop structure, a receiving loop structure galvanically isolated from the transmitting loop structure and positioned relative to the transmitting loop structure such that a magnetic field generated by the transmitting loop structure induces a first voltage in the receiving loop structure, wherein the first voltage is below a threshold value, and a control circuit configured to drive the transmitting loop structure and detect a change in a magnitude of the first voltage in the receiving loop structure in response to the presence of the foreign object within the magnetic field.

Abstract: 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.

Abstract: Techniques for detecting a presence of a metallic and/or a ferromagnetic object over a region for wirelessly transferring power to charge an electric vehicle are presented. An example apparatus includes one or more foreign object detection (FOD) loops arranged in an array over a charging area, at least a portion of the FOD loops being in a first configuration and at least a portion of the FOD loops being second configuration different than the first configuration based on a value indicative of an amount of magnetic coupling between the charging area and a respective one the FOD loops within a corresponding area of the array.

Abstract: Systems and methods are described that reduce magnetic flux density proximate to a wireless charging pad, such as a WEVC pad. These systems and methods control peak magnetic flux density in air around a WEVC pad to reduce potentially dangerous heat produced in foreign metal objects affected by a magnetic field generated by a coil of the WEVC pad. Controlling the peak magnetic flux density results in a safer WEVC pad. Aspects include ferrite tiles being separated by gaps having predefined sizes to increase a magnetic reluctance of a path of the magnetic flux through the ferrite tiles, which reduces a peak magnetic flux density experienced in areas proximate to the coil. In addition, the ferrite tiles can be arranged such that a combination of gaps are aligned with a region overlapping the coil.

Abstract: One innovation includes a system for reducing magnetic flux of a wireless charging field in a wireless power charging system. The system comprises a wireless power transmitter configured to generate the wireless charging field, the field comprising the magnetic flux and a collector comprising a ferromagnetic material and configured to reduce the magnetic flux. The collector is positioned between a first distance and a second distance at a third distance from the transmitter. The collector is configured to reduce the magnetic flux at a first level at the first distance, at a second level at the second distance, and at a third level at the third distance, the third level greater than each of the first and second levels.

Abstract: Techniques for detecting a presence of a foreign object within a region for wirelessly transferring power to charge an electric vehicle are discloses. An example apparatus according to the disclosure includes a foreign object detection (FOD) structure including a transmitting loop structure, a receiving loop structure galvanically isolated from the transmitting loop structure and positioned relative to the transmitting loop structure such that a magnetic field generated by the transmitting loop structure induces a first voltage in the receiving loop structure, wherein the first voltage is below a threshold value, and a control circuit configured to drive the transmitting loop structure and detect a change in a magnitude of the first voltage in the receiving loop structure in response to the presence of the foreign object within the magnetic field.

Abstract: Techniques for detecting a presence of a metallic and/or a ferromagnetic object over a region for wirelessly transferring power to charge an electric vehicle are presented. An example apparatus includes one or more foreign object detection (FOD) loops arranged in an array over a charging area, at least a portion of the FOD loops being in a first configuration and at least a portion of the FOD loops being second configuration different than the first configuration based on a value indicative of an amount of magnetic coupling between the charging area and a respective one the FOD loops within a corresponding area of the array.

Abstract: A method and apparatus for reducing leakage magnetic flux in wireless vehicle charging systems are disclosed. A wireless power receiver may be configured to couple to a wireless field generated by a wireless power transmitter. A portion of the wireless field may comprise the leakage magnetic flux. A leakage collector comprising a ferromagnetic material may be positioned at a distance from the wireless power receiver within the wireless field and may be configured to absorb or redirect at least a portion of the leakage magnetic flux away from an outer edge of an electric vehicle.

Abstract: In an aspect of the disclosure, an apparatus for wirelessly transmitting power is provided. The apparatus includes a communication circuit configured to communicate with a first wireless power transmitter and a second wireless power transmitter. The apparatus further includes a controller circuit configured to identify a first phase of a first current provided to the first wireless power transmitter, the first current generating a first magnetic field. The controller circuit further determines a time to provide a second current to the second wireless power transmitter. The controller circuit further provides the second current at the determined time with a second phase having a phase difference between the first phase configured to reduce a magnitude of a combined magnetic field of the first and second magnetic fields in a region between the first and second wireless power transmitters.

Abstract: This disclosure provides systems, methods and apparatus for avoiding magnetic power loss while providing alternating current through a ferromagnetic material. In one aspect, the ferromagnetic material includes at least one orifice. At least one electrical conduit extends through the at least one orifice from a first region on a first side of the ferromagnetic material to a second region on a second side of the ferromagnetic material, the second side opposite to the first side. The at least one electrical conduit is configured to have at least one alternating current flowing along the at least one electrical conduit between the first region and the second region. The ferromagnetic material and the at least one electrical conduit are configured to reduce power loss caused by a circumferential magnetic flux generated within the ferromagnetic material by the at least one alternating current.

Abstract: One innovation includes a system for reducing magnetic flux of a wireless charging field in a wireless power charging system. The system comprises a wireless power transmitter configured to generate the wireless charging field, the field comprising the magnetic flux and a collector comprising a ferromagnetic material and configured to reduce the magnetic flux. The collector is positioned between a first distance and a second distance at a third distance from the transmitter. The collector is configured to reduce the magnetic flux at a first level at the first distance, at a second level at the second distance, and at a third level at the third distance, the third level greater than each of the first and second levels.

Abstract: A method and apparatus for reducing leakage magnetic flux in wireless vehicle charging systems are disclosed. A wireless power receiver may be configured to couple to a wireless field generated by a wireless power transmitter. A portion of the wireless field may comprise the leakage magnetic flux. A leakage collector comprising a ferromagnetic material may be positioned at a distance from the wireless power receiver within the wireless field and may be configured to absorb or redirect at least a portion of the leakage magnetic flux away from an outer edge of an electric vehicle.

Abstract: This disclosure provides systems, methods and apparatus for avoiding magnetic power loss while providing alternating current through a ferromagnetic material. In one aspect, the ferromagnetic material includes at least one orifice. At least one electrical conduit extends through the at least one orifice from a first region on a first side of the ferromagnetic material to a second region on a second side of the ferromagnetic material, the second side opposite to the first side. The at least one electrical conduit is configured to have at least one alternating current flowing along the at least one electrical conduit between the first region and the second region. The ferromagnetic material and the at least one electrical conduit are configured to reduce power loss caused by a circumferential magnetic flux generated within the ferromagnetic material by the at least one alternating current.