Apple Inc.

Other

Antoin J Russell

Zaki Moussaoui

Bharat K Patel

Jerald Polestico Guillermo

Adam L Schwartz

Sumant Ranganathan

Gianpaolo Lisi

Stephen Christopher Terry

Manisha P Pandya

Liang Chen

Ye Li

Arunim Kumar

Jukka-pekka J Sjoeroos

Zachary Strachan Harris

Mikhal S De Jesus

Andrew Gray

Previn D Nair

Saining Ren

Ron Rafer Floresca

A wireless power transmitter can include a coil, an inverter coupled to the coil, and control circuitry coupled to the inverter that, responsive to receiving a burst request pulse from a wireless power receiver, initiates inverter operation, driving the coil and powering the receiver. The control circuitry can operate inverter switches so bandwidth of the wireless power transfer signal falls within a specified range by: (a) extending a minimum on time of the switches, (b) modifying pulse width modulation (PWM) drive signals supplied to the switches to shape a coil current burst envelope, and/or (c) modifying PWM signal amplitude supplied to the switches. Modifying the PWM drive signals can include using a symmetrical PWM scheme in which the positive and negative pulses are symmetrical in width on a cycle-by-cycle basis or using a complementary PWM scheme in which the positive and negative pulse widths are complementary on a cycle-by-cycle basis.

Frequency management for wireless power transfer

A wireless power relay can include a first wireless power receiver (Rx) configured to receive power from a first wireless power transmitter (Tx) in another device and a second wireless power transmitter (Tx) configured to deliver power to a second wireless power receiver (Rx) in another device. Rxmay be configured to communicate with Txvia a first communication link, and the Txmay be configured to receive communication from Rxvia 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 Rxand its output coupled to Txand 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 Txfrom detecting and improperly interpreting signals from the second communications link.

Wireless power relay with constant power controlled converter

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.

Wireless power system with object detection

A wireless power transmitting device transmits wireless power signals to a wireless power receiving device. The wireless power receiving device has a wireless power receiving coil in a resonant circuit that resonates at a wireless power receiving circuit resonant frequency. The wireless power transmitting device has coils. The coils are supplied with a drive signal in bursts to detect external objects. Measurement circuitry includes an oscillator for supplying the drive signals and a peak detector and analog-to-digital converter for gathering measurements on the coils to which the drive signals have been supplied. Rate-based-filtering is applied to output signals from the analog-to-digital converter to distinguish between temperature drift effects and object placement effects. The frequency of the drive signals is slightly greater than the wireless power receiving circuit resonant frequency.

Wireless charging system with object detection

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.

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. Oscillator circuitry for supplying signals to the output circuitry while making measurements with the measurement circuitry is coupled to the output circuit using an impedance injection network. The impedance injection network includes an inductor and a resistor coupled in series. Control circuitry opens a transistor in the output circuit when making measurements with the measurement circuitry and closes the transistor when transmitting the wireless power signals.

Wireless charging system having measurement circuitry with foreign object detection capabilities

A wireless power transmitting device transmits wireless power signals to a wireless power receiving device using output circuitry that includes an array of wireless power transmitting coils that form a wireless charging surface. During wireless power transmission operations, wireless power signals are transmitted from the array of coils to a wireless power receiving device on the charging surface. Inductance measurement circuitry such as impulse response measurement circuitry and other measurement circuitry is coupled to the output circuitry. Control circuitry in the wireless power transmitting device analyzes signals from the measurement circuitry to produce two-dimensional signal profiles across the wireless charging surface and to compare patterns in these signal profiles to predetermined signal patterns associated with the presence of known power receiving equipment on the wireless charging surface. Based on the analysis, charging parameters may be adjusted or other actions taken.

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San Francisco, CA, United States of America

Antoin J Russell