Wireless power system with power control

    公开(公告)号:US11095162B1

    公开(公告)日:2021-08-17

    申请号:US16930162

    申请日:2020-07-15

    Applicant: Apple Inc.

    Abstract: A wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device and wireless power receiving device may include control circuitry that measures operating parameters. During wireless power transmission operations, the wireless power receiving device may periodically send feedback to the wireless power transmitting device such as in-band wireless power adjustment commands requesting that the wireless power transmitting device adjust the amount of power being transmitted from the wireless power transmitting device to the wireless power receiving device. Faster estimates of desired adjustments to the amount of transmitted power can be made by the wireless power transmitting device using real-time measurements of wireless power transmitting device coil current and wireless power transmitting device coil voltage.

    Input power limited switching regulator

    公开(公告)号:US10938307B2

    公开(公告)日:2021-03-02

    申请号:US16121205

    申请日:2018-09-04

    Applicant: Apple Inc.

    Abstract: This disclosure describes a system and a method to limit (i.e., regulate) the input power of a power converter as a function of the voltage and/or loading condition of a power-limited source such as a battery. In some embodiments, the power converter may comprise a transconductance amplifier that may produce a sink current to a current mirror, which in turn that may provide an adjusted current limit threshold to the power converter. The power converter may utilize the current limit threshold to perform cycle-by-cycle current limiting, thus regulating the input power drawn from the battery.

    Overvoltage Protection in Wireless Power Transfer

    公开(公告)号:US20190052102A1

    公开(公告)日:2019-02-14

    申请号:US15840172

    申请日:2017-12-13

    Applicant: Apple Inc.

    Abstract: Disclosed herein are a method, system and non-transitory program storage device for protecting a power converter from overvoltage conditions in wireless power transfer. In some embodiments, the power converter may use a controllable current sink to discharge an output voltage of the power converter's receiver so as to maintain the output voltage below an overvoltage threshold. In some embodiments, a peak current of the current sink may be controlled as a function of the output voltage. In some embodiments, the current sink may be enabled and/or disabled according to a duty cycle and a frequency, wherein the frequency may be maintained beyond an audible range. In some embodiments, the power converter may bypass the receiver responsive to the output voltage exceeding a limit, thus effectively disabling the power transfer from a transmitter to the receiver.

    Frequency management for wireless power transfer

    公开(公告)号:US12184111B2

    公开(公告)日:2024-12-31

    申请号:US18154383

    申请日:2023-01-13

    Applicant: Apple Inc.

    Abstract: 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.

    Wireless power system with in-band communications

    公开(公告)号:US10998776B2

    公开(公告)日:2021-05-04

    申请号:US16748467

    申请日:2020-01-21

    Applicant: Apple Inc.

    Abstract: A wireless power receiving device has a coil that receives wireless power signals from a wireless power transmitting device and has a rectifier that produces direct-current power across rectifier output terminals using the received wireless power signals. A load in the wireless power receiving device receives a direct-current output voltage from the rectifier output terminals. In-band communications are supported in which an amplitude-shift keying communications scheme or other communications scheme is used by a data transmitter in the wireless power receiving device to transmit in-band data through the coil. In-band data is transmitted by modulating one or more transistors that are coupled to the coil and other wireless power receiving circuitry in series with one or more capacitors and is transmitted by modulating current flow through a ballast transistor or other adjustable load that is coupled across the rectifier output terminals.

    Rectifier arbitration in wireless charging systems

    公开(公告)号:US10355514B2

    公开(公告)日:2019-07-16

    申请号:US15485078

    申请日:2017-04-11

    Applicant: Apple Inc.

    Abstract: A wireless power transmitting device may transmit power wirelessly to a wireless power receiving device. The wireless power receiving device may be a portable electronic device with an array of wireless power receiving coils that receive wireless power from wireless power transmitting coils in the wireless power transmitting device. Each receiving coil in the array of wireless power receiving coils may be coupled to a respective rectifier. Control circuitry of the wireless power receiving device may be configured to determine which rectifiers to enable for synchronous rectification. The control circuitry may be configured to enable at least one rectifier based on the alternating-current voltages produced by each coil in the array of receiving coils. The control circuitry may also be configured to enable at least one rectifier based on the output current from each rectifier.

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