Abstract: An electronic device such as a portable electronic device has wireless power receiving circuitry. A vehicle has a vehicle remote keyless system that transmits beacons. A key receives the beacons and responds with key codes to unlock doors and enable a vehicle ignition in the vehicle. In the presence of wireless power transfer operations there is a risk that wireless power signals will interfere with the reception of the beacons by the key. To ensure that beacons are satisfactorily received, conditions in which there is a risk of interference are detected and corresponding interference mitigation operations are performed.

Abstract: A wireless power transmitting device may transmit wireless power signals to a wireless power receiving device. The wireless power receiving device may have a housing. A display may be mounted in the housing on a front face of the device. A rear housing wall on a rear face of the device may be provided with a wireless power receiving solenoid. The solenoid may have a linear strip shape that extends along a longitudinal axis. The longitudinal axis may extend perpendicularly to a wrist strap coupled to the housing. The wireless power receiving solenoid may have opposing first and second ends. The wireless power transmitting device may have a wireless power transmitting solenoid with opposing first and second ends that are configured to transmit the wireless power signals respectively to the first and second ends of the wireless power receiving device when the wireless power receiving solenoid is within the cradle.

Abstract: A wireless power transmitting device may transmit wireless power signals to a wireless power receiving device. The wireless power receiving device may have a housing. A display may be mounted in the housing on a front face of the device. A rear housing wall on a rear face of the device may be provided with a wireless power receiving solenoid. The solenoid may have a linear strip shape that extends along a longitudinal axis. The longitudinal axis may extend perpendicularly to a wrist strap coupled to the housing. The wireless power receiving solenoid may have opposing first and second ends. The wireless power transmitting device may have a wireless power transmitting solenoid with opposing first and second ends that are configured to transmit the wireless power signals respectively to the first and second ends of the wireless power receiving device when the wireless power receiving solenoid is within the cradle.

Abstract: A wireless power system may have a wireless power transmitting device and a wireless power receiving device. The wireless power receiving device may have a receive coil that receives wireless power signals from the wireless power transmitting device and may have a rectifier that produces direct-current power from the received wireless power signals. The wireless power transmitting device may have an array of transmit coils. Each transmit coil has a respective magnetic coupling coefficient characterizing its magnetic coupling with the receive coil. The wireless power transmitting device may have control circuitry that uses the magnetic coupling coefficient values in selecting transmit coils to use in transmitting wireless power to the wireless power receiving device.

Abstract: A wireless power system may include an electronic device and a removable case. The electronic device and removable case may include wireless charging coils that are inductively coupled when the electronic device and the removable case are physically coupled. In a first mode, while the removable case is inductively coupled to the electronic device and the electronic device is not connected to a wired power source, a coil in the removable case transmits wireless power signals to the electronic device. In a second mode, while the removable case is inductively coupled to the electronic device and the electronic device is connected to a wired power source, the coil in the removable case receives wireless power signals from the electronic device. In a third mode, the removable case receives wireless power with a first coil and transmits wireless power to the electronic device with a second coil.

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: An electronic device in a wireless power system may be operable with a removable accessory such as a case. The device may have coplanar power transmitting and power receiving coils. The transmitting coil may be positioned within a central opening of the receiving coil. The removable accessory may have an embedded receiving coil configured to receive wireless power from the transmitting coil of the electronic device. The receiving coil of the electronic device may receive wireless power from a power transmitting device such as charging mat. The receiving coil of the electronic device may operate up to a higher maximum power than the transmitting coil of the electronic device. The power transmitting coil and power receiving coil in the electronic device may operate at different power transmission frequencies. To mitigate crosstalk, the power transmitting coil's operation frequency may be a non-integer multiple of the power receiving coil's operation frequency.

Abstract: An electronic device in a wireless power system may be operable with a removable accessory such as a case. The device may convey wireless power to, from, or through the case while the device is coupled to the case. The device may have coplanar power transmitting and power receiving coils. The removable accessory may have an embedded switchable ferrimagnetic core and a coil that overlaps the switchable ferrimagnetic core. The switchable ferrimagnetic core may be operable in a first state where the switchable ferrimagnetic core is unsaturated. The switchable ferrimagnetic core may be operable in a second state where the switchable ferrimagnetic core is saturated by a magnetic field from a permanent magnet in a wireless power transmitting device. In the second state, the switchable ferrimagnetic core may have a lower magnetic permeability and higher magnetic reluctance than in the first state.

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 wireless charging mat and method of operating the same. The wireless charging mat includes a detection system configured to determine a location and an orientation of an electronic device on the wireless charging mat. The location and orientation are determined based on detected locations of one or more structural features of the electronic device. The wireless charging mat is operated according to the detected location and orientation.

Abstract: A wireless power relay can include a first wireless power receiver (Rx1) configured to receive power from a first wireless power transmitter (Tx1) in another device and a second wireless power transmitter (Tx2) configured to deliver power to a second wireless power receiver (Rx2) in another device. Rx1 may be configured to communicate with Tx1 via a first communication link, and the Tx2 may be configured to receive communication from Rx2 via a second communication link, both employing modulation of the wireless power signal. The relay may further include a power converter with its input coupled to Rx1 and its output coupled to Tx2 and a constant power controller configured to isolate modulated communication between the communication links. Additionally or alternatively, the relay may include circuitry configured to introduce a jamming signal preventing Tx1 from detecting and improperly interpreting signals from the second communications link.

Abstract: A wireless charging mat and method of operating the same. The wireless charging mat includes a detection system configured to determine a location and an orientation of an electronic device on the wireless charging mat. The location and orientation are determined based on detected locations of one or more structural features of the electronic device. The wireless charging mat is operated according to the detected location and orientation.

Abstract: A power system has a wireless power transmitting device and a wireless power receiving device. Coils in the transmitting device may include a circular coil overlapped by first and second rectangular coils at a charging surface. The rectangular coils each include straight segments extending over a central region of the circular coil. Control circuitry can activate the circular coil to transmit wireless power to a first type of wireless power receiving coil using vertical components of the magnetic field generated by the circular coil. The control circuitry can activate the rectangular coils to transmit wireless power to a second type of wireless power receiving coil using horizontal components of the magnetic field generated by the rectangular coils. The circular and rectangular coils wirelessly charge the power receiving device while located at the same position on the charging surface, regardless of the type of wireless power receiving coil that is used.

Abstract: A power converter can be implemented as a series of power conversion stages, including a wireless power conversion stage. In typical embodiments, the power converter receives power directly from mains voltage and outputs power to a battery within an electronic device. A transmitter side of the power converter converts alternating current received from a power source (e.g., mains voltage) to an alternating current suitable for applying to a primary coil of the wireless power conversion stage of the power converter.

Abstract: A wireless power system has a wireless power transmitting device and multiple wireless power receiving devices. The wireless power transmitting device may have a foldable housing. The wireless power transmitting device has wireless power coils that are used in transmitting wireless power to electronic devices such as cellular telephones, wristwatches, ear buds battery cases, ear buds, computer styluses, and other electronic devices. A rectifier can be coupled to a wireless power coil. In a first mode the coil transmits wireless power to a cellular telephone or other device. In a second mode, the coil is used in receiving wireless power from the cellular telephone or other device. The received wireless power can be retransmitted to other devices.

Abstract: An electronic device such as a portable electronic device has wireless power receiving circuitry. A vehicle has a vehicle remote keyless system that transmits beacons. A key receives the beacons and responds with key codes to unlock doors and enable a vehicle ignition in the vehicle. In the presence of wireless power transfer operations there is a risk that wireless power signals will interfere with the reception of the beacons by the key. To ensure that beacons are satisfactorily received, conditions in which there is a risk of interference are detected and corresponding interference mitigation operations are performed.

Abstract: A wireless power system has a wireless power transmitting device such as a charging mat with a charging surface and a wireless power receiving device that receives wireless power from coils overlapped by the charging surface. The wireless power transmitting device receives load current and load voltage measurements from the wireless power receiving device and uses this information to produce one or more load lines. The load lines may form a family of load lines each associated with a different respective duty cycle used by inverter circuitry in the wireless power transmitting device in transmitting wireless power signals using the coils. The control circuitry can determine whether the wireless power receiving device has moved by comparing current and voltage information from the wireless power receiving device to the family of load lines and can take appropriate action such as measuring coil inductances for use in subsequent coil selection operations.

Abstract: A power system has a wireless power transmitting device and a wireless power receiving device. Coils in the power transmitting and receiving devices are used to transmit and receive wireless power signals. The coils may include pot core coils, figure eight coils, solenoids, and other coils. A solenoid array may extend under a charging surface in a wireless power transmitting device. Solenoids in the array may be separated from each other by small gaps. Solenoids may have rectangular outlines, hexagonal outlines, or other shapes. Pot core coils may have a magnetic material with a circular groove of a groove of other suitable shapes that contains wire windings. Figure eight coils may have first and second adjacent magnetic cores with respective counterclockwise and clockwise wire windings. Magnets and other alignment structures can be used to help align coils in transmitting and receiving devices.

Abstract: An electronic device such as a portable electronic device has wireless power receiving circuitry. A vehicle has a vehicle remote keyless system that transmits beacons. A key receives the beacons and responds with key codes to unlock doors and enable a vehicle ignition in the vehicle. In the presence of wireless power transfer operations there is a risk that wireless power signals will interfere with the reception of the beacons by the key. To ensure that beacons are satisfactorily received, conditions in which there is a risk of interference are detected and corresponding interference mitigation operations are performed.

Abstract: An electronic device such as a portable electronic device has wireless power receiving circuitry. A vehicle has a vehicle remote keyless system that transmits beacons. A key receives the beacons and responds with key codes to unlock doors and enable a vehicle ignition in the vehicle. In the presence of wireless power transfer operations there is a risk that wireless power signals will interfere with the reception of the beacons by the key. To ensure that beacons are satisfactorily received, conditions in which there is a risk of interference are detected and corresponding interference mitigation operations are performed.