Apple Inc.

Rohan Dayal

Zaki Moussaoui

Weihong Qiu

Stephen Christopher Terry

Ye Li

Narendra S Mehta

Adam L Schwartz

Christopher S Graham

Paul J Thompson

Makiko K Brzezinski

Gianpaolo Lisi

Manisha P Pandya

Saining Ren

Inhwan Oh

Bharat K Patel

Liang Chen

Nan Liu

Gaurav Kalra

Malhar V Bhatt

Bingyao Sun

Weihong Qui

A wireless power transfer transmitter can include a transmitter coil configured to deliver power to an inductively coupled receiver coil in a wireless power transfer receiver, a power converter configured to drive the transmitter coil, and means for driving the transmitter coil with a common-mode coupled communication signal to the wireless power transfer receiver. The means for driving the transmitter coil with the common-mode coupled communication signal to the wireless power transfer receiver can include a common mode signal driver configured to receive a data input signal and generate therefrom a signal to be injected into the transmitter coil. Alternatively, the means for driving the transmitter coil with the common-mode coupled communication signal to the wireless power transfer receiver can include a controller configured to drive the inverter with alternating complementary duty cycles.

Inductive power transfer system with common mode channel communication

A wireless power system can include a wireless power transmitter and a wireless power receiver. The transmitter can include a transmit coil, an inverter, and inverter control circuitry that can operate one or more switching devices of the inverter to communicate information to the receiver by controlling a delay between receipt of the burst request pulse and initiating operation of the inverter and/or controlling a polarity of a first pulse of the inverter. The receiver can include a receive coil magnetically coupled to the transmit coil, a rectifier, and rectifier control circuitry that initiates a burst request pulse to initiate operation of a transmitter. The rectifier control circuitry can operate one or more switching devices of the rectifier to communicate information to the transmitter by at least one of short circuiting an LC tank including the receive coil or controlling a polarity of the burst request pulse.

Wireless power transfer with integrated communications

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.

Shared power converter for a wireless transmitter device

A battery case has first and second coils on opposing sides of a battery and has switching circuitry that is coupled between the first and second coils. The battery case has a battery that provides supplemental battery power wirelessly to a wireless power receiving device via the second coil when the switching circuitry is in an open state. The case can also receive power wirelessly with the first coil from a wireless charging mat when the switching circuitry is in the open state. In a closed state, the switching circuitry shorts the first and second coils together so that current flowing through the first coil flows through the second coil in series and so that wireless power from the wireless charging mat that is received with the first coil is transmitted wirelessly to the wireless power receiving device using the second coil.

Wireless power system

This application relates to a wireless charger with increased efficiency during operation. The wireless charging assembly includes a wireless charger and an electronic device. A transmitter coil in the wireless charger can induct magnetic flux to a receiver coil in the electronic device via a magnetic flux pathway.

Wireless magnetic charger with solenoids

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.

Low-profile power converter

A wireless power transmitting device transmits wireless power signals to a wireless power receiving device by supplying drive signals with a duty cycle to a wireless power transmitting coil. The wireless power receiving device has a rectifier and a wireless power receiving coil that receives wireless power signals having the duty cycle from the wireless power transmitting device. The rectifier is coupled to an integrated circuit such as a battery charger integrated circuit. The amount of current drawn by the integrated circuit from the rectifier is adjustable. During operation, control circuitry in the wireless power receiving device sets the current to multiple different values while using sensor circuitry to measure output power from the rectifier. A satisfactory value for the duty cycle can be identified by adjusting the duty cycle while observing when peaks in the output power arise as a function of the different current values.

Wireless charging system with duty cycle control

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.

Wireless power system with resonant circuit tuning

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.

Adaptable power rectifier for wireless charger system

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.

Wireless charging systems with in-band communications

Disclosed are devices, systems, and methods for reducing common mode noise induced in wireless charging circuits of electronic devices. For an electronic device having an inductive receiving coil near an electric shielding layer, differences in parasitic capacitances of the loops of the inductive receiving coil with an electric shielding layer can induce common mode noise. Common mode noise is reduced by a noise-reduction capacitor from the inductive receiving coil to the electric shielding layer together with a grounding resistor from the electric shielding layer to a common ground of the wireless charging circuit.

Common mode noise compensation in wireless power systems

A wireless power transmitting device may have an array of transmitting coils to transmit power wirelessly to a wireless power receiving device having an array of wireless power receiving coils. The receiving device may have a rectifier that receives alternating-current signals from the wireless power receiving coils and provides corresponding rectified direct-current voltage signals to a capacitor and other circuitry. The rectifier circuitry may include bridge circuits each of which is coupled between a respective coil in the array of wireless power receiving coils and the capacitor. The wireless power transmitting coils may be arranged in a hexagonally tiled array. The wireless power receiving coils may include first, second, and third coils that are aligned with respective vertices in an equilateral triangle having sides with lengths equal to half of the center-to-center spacing of the hexagonally tiled transmitting coils.

Wireless charging systems with multicoil receivers

A power converter can be implemented with a boosted-output inverter, which integrates the functionality of a voltage converter (e.g., boost converter) and a voltage inverter. In particular, a boosted-output inverter includes a primary tank inductor coupled in series with a secondary tank inductor at a central node. The boosted-output inverter also includes two voltage-controlled switches that respectively define a charging phase and a discharging phase of the primary tank inductor. While the primary tank inductor is charging, the secondary tank inductor is inverted to ground. In this manner, current though the secondary tank inductor alternates at a voltage boosted by the fly-back voltage of the primary tank inductor exhibited when the primary tank inductor transitions from the charging mode to the discharging mode. In many cases, the secondary tank inductor is a transmit coil of a transmitter of a wireless power transfer system.

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Daly City, CA, United States of America

Rohan Dayal