This disclosure relates to the inductive charging of portable electronic devices. In particular, a charging assembly is disclosed that allows a portable electronic device to be charged in multiple orientations with respect to a charging device. The charging assembly includes two or more separate inductive receiving coils. The inductive receiving coils can be arranged orthogonally with respect to one another by wrapping one or more secondary receiving coils around an antenna. By orienting the receiving coils orthogonally with respect to one another, the likelihood of at least one of the receiving coils being aligned with a charging field emitted by a charging device increases substantially.

The technology described herein relates to techniques for calibrating wireless power transmission systems for operation in multipath wireless power delivery environments. In an implementation, a method of calibrating a wireless power transmission system for operation in a multipath environment is disclosed. The method includes characterizing a receive path from a calibration antennae element to a first antennae element of a plurality of antennae elements of the wireless power transmission system, characterizing a transmit path from the first antennae element to the calibration antennae element, and comparing the transmit path to the receive path to determine a calibration value for the first antennae element in the multipath environment.

An electronic device, a wireless charging device and a wireless charging method, which belong to the technical field of charging. The electronic device comprises: a receiving coil, a receiving circuit, a first switch module and a first control module, wherein the first control module is used for controlling, according to a related parameter for the magnetic coupling strength between the receiving coil and a transmitting coil of a wireless charging device, the turning on and off of at least two first switches in the first switch module, so as to adjust the number of turns of subcoils in the receiving coil that effectively work.

Embodiments described herein provide foreign object detection based on coil current sensing. The transmitter power loss is computed directly based on the coil current, in conjunction with, or in place of the conventional computation based on transmitter input current. The enhanced precision of the computer power loss can be used to more accurately detect a foreign object near the transmitter coil during a wireless power transfer.

A power transmitting apparatus measures a waveform attenuation rate of a transmission power waveform, at a transmission antenna, in a state in which the power transmission by the power transmitting is restricted, sets a threshold used for detecting a foreign object between the power transmitting apparatus and the power receiving apparatus on the basis of the measured waveform attenuation rate, and determines whether or not the foreign object is present on the basis of the waveform attenuation rate measure after the threshold is set and the threshold.

A wireless power transfer pad for wireless power transfer with active field cancellation using multiple magnetic flux sinks includes a ferrite structure, a center coil positioned adjacent to the ferrite structure, and a plurality of side coils positioned around a perimeter of the center coil and positioned adjacent to the ferrite structure. A direction of current flow of the center coil is opposite a current flow in each of the plurality of side coils such that current flowing in a portion of the center coil adjacent to a portion of a side coil of the plurality of side coils is in a same direction as current in the portion of the side coil.

This disclosure provides systems, devices, apparatus and methods, including computer programs encoded on storage media, for wireless power transmission. A wireless power receiving apparatus may be configured to combine power from multiple wireless power signals. In some implementations, the wireless power receiving apparatus may combine wireless power received from multiple secondary coils to provide a combined wireless power signal to a load, such as a battery charger or electronic device. In some implementations, each set of primary coil and secondary coil may utilize low power wireless power signals (such as 15 Watts or less) in accordance with a wireless charging standard. By combining power from multiple low power wireless power signals, the wireless power receiving apparatus may support higher power requirements of an electronic device. The disclosed designs may minimize electromagnetic interference (EMI) and provide greater efficiency of wireless power transfer.

A power receiving apparatus capable of receiving power transmitted from a power transmitting apparatus capable of executing first foreign object detection and second foreign object detection, transmits, to the power transmitting apparatus, data to be used by the power transmitting apparatus to execute the first foreign object detection; before transmitting the data, determines whether a predetermined condition for the power transmitting apparatus to execute the second foreign object detection different from the first foreign object detection is satisfied; and transmits, to the power transmitting apparatus, a signal for causing the power transmitting apparatus to execute the second foreign object detection in accordance with the determination.

Wireless chargers that can properly align and securely hold an electronic device, provide power to more than one electronic device, and fold into a compact shape. One example can provide a wireless charger having an alignment feature to align an electronic device to the wireless charger. The wireless charger can include a first leaf having first charging components for charging a first electronic device and a second leaf having a charging puck that includes second charging components for charging a second electronic device. The charging puck can move between a down position and an up position. The charging puck can be moved away from the second leaf while in the up position. The charging puck can retract when moved to the down position. The first leaf and the second leaf can fold together into a compact shape.

An example method performed by a wireless-power-transmitting device that includes an antenna array is provided. The method includes radiating electromagnetic waves that form a maximum power level at a first distance away from the antenna array. Moreover, a power level of the radiated electromagnetic waves decreases, relative to the maximum power level, by at least a predefined amount at a predefined radial distance away from the maximum power level. In some embodiments, the method also includes detecting a location of a wireless-power-receiving device, whereby the location of the wireless-power-receiving device is further from the antenna array than a location of the maximum power level.