Abstract: In one example, an apparatus for wireless power transfer may include a resonant section of a wireless power transfer converter, a first switching section having a full-bridge topology, a second switching section including bidirectional switches in a full-bridge topology, and a transformer with N turns having a first side and a second side. The first switching section may include a first leg and a second leg, each having a center point. The resonant section may include a first connection and a second connection. The second switching section may include a first leg and a second leg, each having a center point. A first connection of the first side of the transformer may be connected in series with the second connection of the resonant section. The first connection of the resonant section and a second connection of the first side of the transformer may be connected to the center points of the first switching section, respectively.

Abstract: Described herein is a wireless transfer system that includes a lower charging pad having at least one first winding, the at least one first winding configured to, upon being provided a first current, cause a second current to be induced in the at least one second winding of an upper charging pad. The lower charging pad comprises a combination of one or more inclined portions and a position adjustment mechanism positioned under a movable magnetic structure within the lower charging pad. Parameters of the second current is dependent upon a size of a gap between the one or more first vertical portions and the one or more inclined portions, the size of the gap being adjusted by first changing a position of the one or more vertical portions with respect to the one or more inclined portions.

Abstract: A wireless power transfer pad apparatus may include a ferrite structure and four windings adjacent to the ferrite structure. The ferrite structure may include a magnetic pathway. A ferrite pathway between adjacent windings of the four windings may have a thickness and a width to provide a low impedance, unsaturated magnetic pathway for an electromagnetic field generated by the adjacent windings. Other examples may be described and claimed.

Abstract: In one example, an apparatus for wireless power transfer may include a resonant section of a wireless power transfer converter, a first switching section having a full-bridge topology, a second switching section including bidirectional switches in a full-bridge topology, and a transformer with N turns having a first side and a second side. The first switching section may include a first leg and a second leg, each having a center point. The resonant section may include a first connection and a second connection. The second switching section may include a first leg and a second leg, each having a center point. A first connection of the first side of the transformer may be connected in series with the second connection of the resonant section. The first connection of the resonant section and a second connection of the first side of the transformer may be connected to the center points of the first switching section, respectively.

Abstract: An apparatus for wireless power transfer may be configured to receive power wirelessly and to output power to a load. The apparatus may include a wireless power transfer pad configured to receive power wirelessly. The apparatus may include a secondary circuit having a rectification section arranged to receive alternating current from the wireless power transfer pad and output rectified current to the load via a positive bus. The rectification section may include a first rectification device connected to the positive bus. The rectification section may include a capacitor connected between the first rectification device and a negative bus connected to the rectification section and arranged for connection to the load. Other examples may be described and claimed.

Abstract: A wireless power transfer pad apparatus may include a ferrite structure and four windings adjacent to the ferrite structure. The ferrite structure may include a magnetic pathway. A ferrite pathway between adjacent windings of the four windings may have a thickness and a width to provide a low impedance, unsaturated magnetic pathway for an electromagnetic field generated by the adjacent windings. Other examples may be described and claimed.

Abstract: An apparatus for wireless power transfer is disclosed. An alternate apparatus and a system perform the functions of the apparatus. The apparatus includes a wireless power transfer (“WPT”) pad, a secondary circuit with a rectification section that receives power from the WPT pad, a capacitor, and a first rectification device connected to the capacitor. The capacitor and first rectification device are connected in parallel with the rectification section and in parallel with a load. The apparatus includes a second rectification device connected to the rectification section and an intermediate node between the capacitor and first rectification device.

Abstract: Described herein is a wireless transfer system that includes multiple charging pads. Each of the wireless power transfer pads (WPT) includes a first winding comprising conductive wiring, the first winding positioned a distance from a center of the respective WPT pad, a second winding comprising conductive wiring, the second winding positioned the distance from the center of the WPT pad, and a third winding comprising conductive wiring, the third winding positioned the distance from the center of the WPT pad, wherein the individual windings are positioned at equal distances from the other of the three windings.

Abstract: A wireless power transfer (“WPT”) pad apparatus includes a first winding adjacent to the ferrite structure, where the first winding is arranged in a spiral-type pattern, and a second winding adjacent to the ferrite structure. The second winding is arranged in a spiral-type pattern and the second winding wound interleaved to the first winding. The first and second windings are arranged to compensate for a difference in length between the first winding and the second winding for portions of the first and second windings wound adjacent to each other.

Abstract: An apparatus for secondary wireless power transfer includes a WPT secondary pad that receives power wirelessly from a WPT primary pad. The secondary pad includes a first winding and a second winding in parallel with the first winding. The apparatus includes a first rectification section that receives power from the first winding and a second rectification section that receives power from the second winding. The first rectification section is connected in parallel with the second rectification section. The parallel connection between the first and second rectification sections form output terminals. The apparatus includes a switch connecting the first winding in series with the second winding and a controller that intermittently opens and closes the switch to control voltage and current at the output terminals.

Abstract: Described herein is a structure, the implementation of which may result in optimization of power transfer within a wireless power transfer pad. Such a structure comprises two planes in parallel that each comprise multiple windings. Additionally, the structure may include two magnetic structures that each pass through the centers of the multiple windings of one of the respective planes. In some embodiments, a magnetic structure may include a main section and two vertical sections. In some cases, the magnetic structure may further include at least one side section that connects with a vertical section.

Abstract: A vault apparatus for wireless power transfer includes a vault comprising an opening for a wireless power transfer (“WPT”) pad. The opening is located on a top of the vault. The vault apparatus includes a junction box formed into the vault. The junction box includes an opening oriented toward the top of the vault. The vault apparatus includes a sealing ring that maintains a WPT pad fixed in the vault where a portion of the sealing ring covers the junction box.

Abstract: A wireless power transfer (“WPT”) pad includes a plurality of capacitors and a winding shaped for wireless power transfer. The winding is divided into a plurality of winding sections. The plurality of winding sections are connected in series with one or more capacitors of the plurality of capacitors connected in series between winding sections.

Abstract: An apparatus for current sharing for wireless power transfer is disclosed. The apparatus includes two or more power converter apparatuses. Each power converter apparatus is connected to a primary wireless power transfer pad. The apparatus includes one or more ferrite structures where each ferrite structure includes a conductor of at least one power converter apparatus of the two or more power converter apparatuses passing through the ferrite structure and each ferrite structure includes two or more conductors. The conductors passing through a ferrite structure of the one or more ferrite structures are arranged to maintain equal current sharing between the conductors passing through the ferrite structure.

Abstract: A wireless power transfer (“WPT”) pad apparatus includes a first winding adjacent to the ferrite structure, where the first winding is arranged in a spiral-type pattern, and a second winding adjacent to the ferrite structure. The second winding is arranged in a spiral-type pattern and the second winding wound interleaved to the first winding. The first and second windings are arranged to compensate for a difference in length between the first winding and the second winding for portions of the first and second windings wound adjacent to each other.

Abstract: A wireless power transfer (“WPT”) pad with a pyramid-shaped ferrite chimney is disclosed. The WPT pad includes a winding comprising a conductor where the conductor is wound in a planar configuration. The winding includes a center point about which the winding is wound. The WPT pad includes a ferrite structure that includes a parallel section located on a side of the winding with at least a portion in parallel with the winding and a chimney section in magnetic contact with the parallel section and located at the center point of the winding. The chimney section extends perpendicular to the parallel section.

Abstract: A wireless power transfer (“WPT”) pad with a ferrite chimney is disclosed. The WPT pad includes a winding with a conductor where the conductor is wound in a planar configuration. The winding includes a center section about which the winding is wound. The WPT pad includes a ferrite structure with a parallel section located on a side of the winding with at least a portion in parallel with the winding, and a chimney section in magnetic contact with the parallel section and located in the center section of the winding, the chimney section extending perpendicular to the parallel section.

Abstract: A wireless power transfer (“WPT”) pad apparatus includes a ferrite structure and four windings adjacent to the ferrite structure. A horizontal surface of the ferrite structure is adjacent to each of the four windings and each of the four windings are wound in a horizontal pattern that is planar to the horizontal surface. The four windings are arranged in a two-by-two square pattern in a north-south-north-south polarity arrangement.

Abstract: A transmission cable to reduce radiated electromagnetic radiation includes a first conductor with current flowing in a positive direction, a second conductor with a current flowing in a negative direction, where the negative direction is opposite the positive direction and the current in the first conductor equal to the current in the second conductor, a third conductor with current flowing in the positive direction and a fourth conductor with a current flowing in the negative direction. The current in the third conductor is equal to the current in the fourth conductor. The first conductor, the second conductor, the third conductor, and the fourth conductor are arranged in a symmetrical square pattern and the conductors are each on a corner of the square pattern. The first conductor is opposite the third conductor and adjacent to the second conductor and the fourth conductor.

Abstract: An apparatus includes a ping detection module that detects a ping signal transmitted from a secondary pad to a primary pad. The secondary pad is located on a mobile device and the primary pad located on a stationary WPT device, where the stationary WPT device transmits power through the primary pad to the secondary pad of the mobile device during a wireless power transfer operation. The ping signal includes a mobile device ID and the mobile device ID is unique to the mobile device. The apparatus includes an ID detection module that detects the mobile device ID from the ping signal received at the primary pad and a pairing module that pairs the stationary WPT device with the mobile device in response to detecting the mobile device ID of the mobile device.