A variable magnetic field in which a power-supplying coil and a power supplying resonator exist is generated only by the power-supplying coil. Power-supplying coils and each of which generates a variable magnetic field due to the supply of a variable current via a first current path on one coil end a side and a second current path on the other coil end side; resonance capacitors which are provided on the first current path and the second current path; and a power-supplying coil short-circuit mechanism which is able to cause at least one of the power-supplying coils and to function as a power supplying resonator by allowing the end portions and of the first current path and the second current path to short-circuit with each other are provided.

Various examples are provided for wireless power charging for versatile receiver positions. In one example, a three dimensional array of transmitter coils is positioned around a charging area. A control circuit causes the array of transmitter coils to generate a magnetic field that charges a device with any position and orientation in the charging area.

An inductive power transfer (IPT) system may include an inductive power transmitter having at least one power transmitting coil that generates an IPT field and an IPT director unit over the inductive power transmitter. The IPT director unit may include a low reluctance element such as a magnetic core configured to direct the IPT field from the inductive power transmitter to an inductive power receiver held in place over the IPT director unit (e.g., by a housing of the IPT director unit). While the IPT director unit directs the IPT field from the inductive power transmitter to the inductive power receiver, a mean direction and density of the IPT field entering the low reluctance element from the inductive power transmitter may be different from the mean direction and density of the IPT field exiting the low reluctance element towards the inductive power receiver.

A magnetic alignment system can include a primary annular magnetic alignment component and a secondary annular magnetic alignment component. The primary alignment component can include an inner annular region having a first magnetic orientation, an outer annular region having a second magnetic orientation opposite to the first magnetic orientation, and a non-magnetized central annular region disposed between the primary inner annular region and the primary outer annular region. The secondary alignment component can have a magnetic orientation with a radial component.

A magnetic alignment system can include a primary annular magnetic alignment component and a secondary annular magnetic alignment component. The primary alignment component can include an inner annular region having a first magnetic orientation, an outer annular region having a second magnetic orientation opposite to the first magnetic orientation, and a non-magnetized central annular region disposed between the primary inner annular region and the primary outer annular region. The secondary alignment component can have a magnetic orientation with a radial component.

A magnetic alignment system can include a primary annular magnetic alignment component and a secondary annular magnetic alignment component. The primary alignment component can include an inner annular region having a first magnetic orientation, an outer annular region having a second magnetic orientation opposite to the first magnetic orientation, and a non-magnetized central annular region disposed between the primary inner annular region and the primary outer annular region. The secondary alignment component can have a magnetic orientation with a radial component. Additional features, such as a rotational magnetic alignment component and/or an NFC coil and circuitry can be included.

A magnetic alignment system can include a primary annular magnetic alignment component and a secondary annular magnetic alignment component. The primary alignment component can include an inner annular region having a first magnetic orientation, an outer annular region having a second magnetic orientation opposite to the first magnetic orientation, and a non-magnetized central annular region disposed between the primary inner annular region and the primary outer annular region. The secondary alignment component can have a magnetic orientation with a radial component. Additional features, such as a rotational magnetic alignment component and/or an NFC coil and circuitry can be included.

A magnetic alignment system can include a primary annular magnetic alignment component and a secondary annular magnetic alignment component. The primary alignment component can include an inner annular region having a first magnetic orientation, an outer annular region having a second magnetic orientation opposite to the first magnetic orientation, and a non-magnetized central annular region disposed between the primary inner annular region and the primary outer annular region. The secondary alignment component can have a magnetic orientation with a radial component. Additional features, such as a rotational magnetic alignment component and/or an NFC coil and circuitry can be included.

A leakage magnetic field shielding device includes: a leakage magnetic field determining unit for determining phase and magnitude of a leakage magnetic field based on information obtained from a power supply device and a current collector device; a shielding current controller for determining a shielding current based on the phase and magnitude of the leakage magnetic field and supplying the determined shielding current to the leakage magnetic field shielding device; and a shielding unit for shielding the leakage magnetic field by generating a shielding magnetic field in accordance with the supply of the shielding current. The shielding unit has a multiple resonance characteristic depending on an arrangement of capacitors and coils and is disposed to surround the power supply device or the current collector device. The shielding magnetic field has resonance frequencies canceling magnetic fields corresponding to fundamental frequency and multiple frequency of the leakage magnetic field.

A wireless power transmission system includes a transmission antenna that has a source antenna coil and an internal repeater coil. The system further includes two demodulation circuits, for demodulating incoming communications from a power receiver. One demodulation circuit receives sensed signals at the source coil and the other receives sensed signals at the internal repeater coil. The pair of sensed signals are then summed at a summing amplifier to generate a communications signal for input to a controller of the wireless power transmission system.