Abstract: A wireless power transmitter can include a wireless power transfer coil designed to magnetically couple with a corresponding coil in a wireless power receiver to facilitate wireless power transfer from the wireless power transmitter to the wireless power receiver, a power converter configured to drive the wireless power transfer coil, and control and communications circuitry coupled to the wireless power transfer coil and the power converter. The control and communications circuitry can be configured to operate the power converter to drive the wireless power transfer coil so as to transfer power to the wireless power receiver in accordance with a negotiated power transfer. Simultaneously during power transfer, the control and communications circuitry can send a polling signal to detect a foreign object including a wireless transponder and reduce or stop wireless power transfer upon receiving a response to the polling signal from a foreign object including a wireless transponder.

Abstract: A device in a wireless power system may be operable with a removable accessory such as a case. The device may transmit or receive wireless power through the case while the electronic device is coupled to the case. The case may have a folio shape with a front cover portion that covers the display of the electronic device. The case may have an embedded ferrimagnetic core that relays magnetic flux during wireless power transfer operations. Magnetic alignment structures in the case may position the ferrimagnetic core in the case in a high magnetic flux density region between the power transmitting device and the power receiving device. The ferrimagnetic core relays the magnetic flux between a transmitting coil in the power transmitting device and a receiving coil in the power receiving device. The ferrimagnetic core may be formed in a front portion, a sidewall, or a rear wall of a case.

Abstract: A personal electronic device (e.g., a tablet computer) may be configured to wirelessly charge an accessory (e.g., a stylus) through a display face of the device. At least a portion of the display face may be transparent to facilitate display viewing. A wireless charging assembly disposed within the enclosure may include a core having one or more windings disposed thereon, which may be configured to generate a magnetic flux above the display face to couple to the accessory. The core may be a pot core, a modified pot core, or may have another shape, such as a PQ core. The one or more windings may be disposed on one or more posts of a pot core, or additionally or alternatively, may be disposed on another portion of the core. A metallic shield may be disposed about the wireless charging assembly, thereby surrounding multiple sides of the wireless charging assembly.

Abstract: A personal electronic device (e.g., a tablet computer) may be configured to wirelessly charge an accessory (e.g., a stylus) through a display face of the device. At least a portion of the display face may be transparent to facilitate display viewing. A wireless charging assembly disposed within the enclosure may include a core having one or more windings disposed thereon, which may be configured to generate a magnetic flux above the display face to couple to the accessory. The core may be a pot core, a modified pot core, or may have another shape, such as a PQ core. The one or more windings may be disposed on one or more posts of a pot core, or additionally or alternatively, may be disposed on another portion of the core. A metallic shield may be disposed about the wireless charging assembly, thereby surrounding multiple sides of the wireless charging assembly.

Abstract: A device in a wireless power system may be operable with a removable accessory such as a case. The device may transmit or receive wireless power through the case while the electronic device is coupled to the case. The case may have a folio shape with a front cover portion that covers the display of the electronic device. The case may have an embedded ferrimagnetic core that relays magnetic flux during wireless power transfer operations. Magnetic alignment structures in the case may position the ferrimagnetic core in the case in a high magnetic flux density region between the power transmitting device and the power receiving device. The ferrimagnetic core relays the magnetic flux between a transmitting coil in the power transmitting device and a receiving coil in the power receiving device. The ferrimagnetic core may be formed in a front portion, a sidewall, or a rear wall of a case.

Abstract: In an inductively coupled power transmitter a force detector that detects the presence of a potential device by monitoring forces applied to a surface of the power transmitter and activates the inductively coupled power transmitter upon detection of a potential device. An inductively coupled power transmitter having a proximity detector that detects the presence and location of a potential device by monitoring the proximity of devices to a surface of the power transmitter and activates the inductively coupled power transmitter upon detection of a potential device. The transmitter preferably has one or more detection coils each having an area much greater than that of the transmitter coils for detecting the presence of a potential device.

Abstract: In an inductively coupled power transmitter a force detector that detects the presence of a potential device by monitoring forces applied to a surface of the power transmitter and activates the inductively coupled power transmitter upon detection of a potential device. An inductively coupled power transmitter having a proximity detector that detects the presence and location of a potential device by monitoring the proximity of devices to a surface of the power transmitter and activates the inductively coupled power transmitter upon detection of a potential device. The transmitter preferably has one or more detection coils each having an area much greater than that of the transmitter coils for detecting the presence of a potential device.

Abstract: A magnetic shield for shielding adjacent coils of an ICPT system. One or more conductors are configured to distribute induced eddy currents from the surface of the shield to below the surface and thus reduce heating due to eddy currents. The magnetic shield may be employed to transfer power over rotary couplings, such as the shaft of a wind turbine.

Abstract: A contactless inductively coupled power transfer system is provided including multiple pairs of power transmitter and power receiver coils and a power management module for controlling the supply of power to transmitter coils or the power supplied by the power receiver module to loads. The design is particularly suited for use in a wind turbine to supply power to the nacelle. The transmitter coils may be driven in phase at the same frequency or at different frequencies selected to avoid interaction between transmitter coils and the power transmitter module. The transmitter and receiver coils may be arranged in a traditional slip ring type configuration with adjacent coil pairs are physically spaced apart to avoid cross coupling with adjacent transmitter and receiver coil pairs shielded from each other. The power transmitter module may employ Zero Voltage Switching (ZVS).

Abstract: A magnetic shield for shielding adjacent coils of an ICPT system. One or more conductors are configured to distribute induced eddy currents from the surface of the shield to below the surface and thus reduce heating due to eddy currents. The magnetic shield may be employed to transfer power over rotary couplings, such as the shaft of a wind turbine.

Abstract: A magnetic shield for shielding adjacent coils of an ICPT system. One or more conductors are configured to distribute induced eddy currents from the surface of the shield to below the surface and thus reduce heating due to eddy currents. The magnetic shield may be employed to transfer power over rotary couplings, such as the shaft of a wind turbine.

Abstract: A wirelessly rechargeable battery is provided having coils oriented off major battery axes to facilitate good coupling with power transmitter magnetic fields. A magnetic core may house charging electronics for a compact form factor. A wireless power transmitter that produces fields to maximize coupling with receiver coils.

Abstract: A wirelessly rechargeable battery is provided having coils oriented off major battery axes to facilitate good coupling with power transmitter magnetic fields. A magnetic core may house charging electronics for a compact form factor. A wireless power transmitter that produces fields to maximize coupling with receiver coils.

Abstract: In an inductively coupled power transmitter a force detector that detects the presence of a potential device by monitoring forces applied to a surface of the power transmitter and activates the inductively coupled power transmitter upon detection of a potential device. An inductively coupled power transmitter having a proximity detector that detects the presence and location of a potential device by monitoring the proximity of devices to a surface of the power transmitter and activates the inductively coupled power transmitter upon detection of a potential device. The transmitter preferably has one or more detection coils each having an area much greater than that of the transmitter coils for detecting the presence of a potential device.

Abstract: A contactless power receiver is provided with a dynamically tuned pick up coil. The power transfer capacity of this power receiver is dynamically tuned using semiconductor devices that are operated in linear mode over part of their operation. The semiconductor devices are driven by a controller that is configured to implement a range of control strategies depending on system requirements. The semiconductor device may be used by itself or in conjunction with reactive elements to dynamically tune the pick up coil. In some implementations the contactless power receiver maybe configured to work with a consumer electronic or a wireless sensor device. The contactless power receiver can be integrated with the energy storage component of the device to provide a retrofit solution for existing products. The device can then be placed in vicinity of a planar magnetic field generated by a charging pad.

Abstract: An inductively coupled power transfer receiver including a tunable circuit and a power supply circuit. The tunable circuit includes a power receiving coil in series with a first capacitance and a first variable impedance connected in parallel with the power receiving coil. The variable impedance includes at least one impedance element and one or more semiconductor devices for controlling the effective impedance of the first variable impedance. The first variable impedance may be a second capacitance in series with the first semiconductor device; an inductance in parallel with the first semiconductor device; a second capacitance in parallel with the first semiconductor device; or a capacitance and an inductor in parallel with the first semiconductor device. The power supply circuit includes a power control circuit which provides a control signal to the first variable impedance based on an output voltage produced by the power supply circuit.

Abstract: A wirelessly rechargeable battery is provided having coils oriented off major battery axes to facilitate good coupling with power transmitter magnetic fields. A magnetic core may house charging electronics for a compact form factor. A wireless power transmitter that produces fields to maximize coupling with receiver coils.

Abstract: A contactless inductively coupled power transfer system is provided_including multiple pairs of power transmitter and power receiver coils and a power management module for controlling the supply of power to transmitter coils or the power supplied by the power receiver module to loads. The design is particularly suited for use in a wind turbine to supply power to the nacelle. The transmitter coils may be driven in phase at the same frequency or at different frequencies selected to avoid interaction between transmitter coils and the power transmitter module. The transmitter and receiver coils may be arranged in a traditional slip ring type configuration with adjacent coil pairs are physically spaced apart to avoid cross coupling with adjacent transmitter and receiver coil pairs shielded from each other. The power transmitter module may employ Zero Voltage Switching (ZVS).

Abstract: A magnetic shield for shielding adjacent coils of an ICPT system. One or more conductors are configured to distribute induced eddy currents from the surface of the shield to below the surface and thus reduce heating due to eddy currents. The magnetic shield may be employed to transfer power over rotary couplings, such as the shaft of a wind turbine.

Abstract: A contactless power receiver is provided with a dynamically tuned pick up coil. The power transfer capacity of this power receiver is dynamically tuned using semiconductor devices that are operated in linear mode over part of their operation. The semiconductor devices are driven by a controller that is configured to implement a range of control strategies depending on system requirements. The semiconductor device may be used by itself or in conjunction with reactive elements to dynamically tune the pick up coil. In some implementations the contactless power receiver maybe configured to work with a consumer electronic or a wireless sensor device. The contactless power receiver can be integrated with the energy storage component of the device to provide a retrofit solution for existing products. The device can then be placed in vicinity of a planar magnetic field generated by a charging pad.