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: 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 wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device may be a wireless charging mat or other device with one or more wireless power transmitting coils for transmitting wireless power signals. The wireless power receiving device may be a portable electronic device with one or more wireless power receiving coils for receiving the transmitted wireless power signals. The wireless power transmitting device may have foreign object detection coils. Q-factor measurements may be made on the transmitting coil during wireless power transmission and/or voltage measurements may be made using the foreign object detection coils to detect whether a foreign object is present. The foreign object detection coils may include overlapping coils with different winding patterns to enhance foreign object detection coverage.

Abstract: Electronic apparatuses according to embodiments of the present technology may include an electronic device a first surface and a second surface opposite the first. The electronic device may include a battery and a wireless charging coil within an interior volume of the device. The electronic device may include a first magnetic conductor and positioned between the battery and the wireless charging coil. The electronic device may also include an integrated circuit coupled with the battery and the wireless charging coil. The apparatuses may include a case extending about the electronic device. The case may be characterized by a first surface and a second surface. The case may be characterized by a thickness between the first surface of the case and the second surface of the case. The case may include a second magnetic conductor incorporated within the thickness of the case at the second surface of the case.

Abstract: A wireless power system may use a wireless power transmitting device to transmit wireless power to a wireless power receiving device. The wireless power transmitting device may have an array of coils that extend under a wireless charging surface. Control circuitry may supply alternating-current control signals to inverters. The inverters are coupled to resonant circuits. Each resonant circuit includes a capacitor coupled to a respective one of the coils. During operation, wireless power signals are transmitted from the coils to the wireless power receiving device through the charging surface. The capacitor associated with each resonant circuit may potentially be individually selected to enhanced uniformity of the wireless power transmitting device. The array of coils may have multiple layers and the capacitors in each layer may have different respective values.

Abstract: A transmitter device is configured to transfer energy to multiple receiver devices. The transmitter device includes multiple transmitter coils, and a shared power converter is coupled to each transmitter coil. The shared power converter includes a leading half bridge and multiple trailing half bridges. Each transmitter coil is coupled between the leading half bridge and a respective one of the trailing half bridges. The shared power converter is dynamically configurable in that the leading half bridge may be coupled to multiple trailing half bridges when energy is to be transferred wirelessly to two or more receiver devices. The leading half bridge simultaneously operates with each trailing half bridge as an independent full-bridge phase shift inverter. A signal supplied to each transmitter coil is independently regulated by controlling a phase shift of a respective trailing half bridge with respect to the leading half bridge.

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 transmission system has a wireless power receiving device that can be charged using multiple different types of wireless power transmitting devices. The different types of wireless power transmitting devices have power transmitting coils that exhibit different levels of magnetic coupling with the power receiving coil of the wireless power receiving device. The wireless power receiving device may include capacitors, resistors, and/or other loading circuits that can be independently switched into use depending on the level of magnetic coupling that is detected, on a rectified voltage level, on the size of the output load, and/or on information conveyed during handshaking operations to present a desired impedance adjustment at the power receiving coil so that data signal can be properly conveyed between the power receiving device and the power transmitting device.

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 transmission system has a wireless power receiving device that is located on a charging surface of a wireless power transmitting device. The wireless power transmitting device uses measurement circuitry such as coil impedance measurement circuitry or impulse-response circuitry that makes coil inductance measurements to monitor the charging surface for the presence of the wireless power receiving device. In response to detecting that the wireless power receiving device is present on the charging surface, the wireless power transmitting device and the wireless power receiving device establish a wireless communications link. The wireless power transmitting device transmits information on wireless power transmission capabilities of the wireless power transmitting device to the wirelessly power receiving device. The receiving device selects desired settings and transmits these to the transmitting device.

Abstract: An embodiment of a circuit includes a circuit module and an inductor disposed over and electrically coupled to the module. Disposing the inductor over the module may reduce the area occupied by the circuit as compared to a circuit where the inductor is disposed adjacent to the module, or to a circuit where the inductor is disposed in the module adjacent to other components of the module. Furthermore, disposing the inductor outside of the module may allow one to install or replace the inductor.

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 transmitter device is configured to transfer energy to multiple receiver devices. The transmitter device includes multiple transmitter coils, and a shared power converter is coupled to each transmitter coil. The shared power converter includes a leading half bridge and multiple trailing half bridges. Each transmitter coil is coupled between the leading half bridge and a respective one of the trailing half bridges. The shared power converter is dynamically configurable in that the leading half bridge may be coupled to multiple trailing half bridges when energy is to be transferred wirelessly to two or more receiver devices. The leading half bridge simultaneously operates with each trailing half bridge as an independent full-bridge phase shift inverter. A signal supplied to each transmitter coil is independently regulated by controlling a phase shift of a respective trailing half bridge with respect to the leading half bridge.

Abstract: An embodiment of a circuit includes a circuit module and an inductor disposed over and electrically coupled to the module. Disposing the inductor over the module may reduce the area occupied by the circuit as compared to a circuit where the inductor is disposed adjacent to the module, or to a circuit where the inductor is disposed in the module adjacent to other components of the module. Furthermore, disposing the inductor outside of the module may allow one to install or replace the inductor.

Abstract: 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 a ferritic core having two legs extending in different directions from a joint region. 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.

Abstract: A power converter including a rectifier circuit and a method for rectifying an incoming alternating current. The rectifier circuit may alter its output voltage according to varying conditions of the power converter. The variations may include voltage changes at the input or output.

Abstract: A wireless power transmitting device transmits wireless power signals to a wireless power receiving device using an output circuit that includes a wireless power transmitting coil. Measurement circuitry is coupled to the output circuit to help determine whether the wireless power receiving device is present and ready to accept transmission of wireless power. The measurement circuitry includes a measurement circuit that is coupled to the output circuit and that measures signals while oscillator circuitry supplies the output circuit with signals at a probe frequency. The measurement circuitry also includes a measurement circuit that is coupled to the output circuit and that measures signals while the oscillator circuitry sweeps signals applied to the output circuit between a first frequency and a second frequency to detect sensitive devices such as radio-frequency identification devices. Impulse response circuitry in the measurement circuitry is used to make inductance and Q factor measurements.

Abstract: A wireless power transmitting device may have control circuitry that supplies drive signals to a coil to produce wireless power signals. The wireless power receiving device may have a coil that receives the transmitted wireless power signals from the wireless power transmitting device. The wireless power receiving device may have a rectifier that rectifies signals received by the coil in the wireless power receiving device and that provides a rectified voltage to a capacitor. A charger in the wireless power receiving device may charge a battery in the device using the rectified voltage. When it is desired to convey information to the wireless power transmitting device, the wireless power transmitting device may cease the transmission of wireless power and the wireless power receiving device may modulate transistors in the rectifier to transmit data to the wireless power transmitting device.

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 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. A charging status indicator may be displayed by the wireless power receiving device during wireless power transmission. Control circuitry in the wireless power receiving device may monitor the output voltage to determine whether wireless power transmission has been lost. The charging status indicator may continue to be displayed for a debounce period following detection of loss of wireless power transmission. The debounce period may be adjusted based on whether power loss is due to user movement of the receiving device or termination of power transmission by the transmitting device.

Abstract: A wireless power transmission system has a wireless power receiving device that can be charged using multiple different types of wireless power transmitting devices. The different types of wireless power transmitting devices have power transmitting coils that exhibit different levels of magnetic coupling with the power receiving coil of the wireless power receiving device. The wireless power receiving device may include capacitors, resistors, and/or other loading circuits that can be independently switched into use depending on the level of magnetic coupling that is detected, on a rectified voltage level, on the size of the output load, and/or on information conveyed during handshaking operations to present a desired impedance adjustment at the power receiving coil so that data signal can be properly conveyed between the power receiving device and the power transmitting device.