Wireless charging device, method of operating a wireless charging device, and storage medium

Abstract

This application relates to a wireless charging device, a method for operating the wireless charging device, and a storage medium. The wireless charging device has a plurality of charging units disposed on a first surface and a processor. The processor is configured to provide a charging current to a first charging coil in the surface of the wireless charging device, determine that the impedance of a resonant circuit has changed from a threshold or setpoint impedance, and restore the threshold or setpoint impedance by modifying the frequency of the charging current. The resonant circuit may include the first charging coil. A method for operating the wireless charging device includes: providing a charging current to the first charging coil in the surface of the wireless charging device; determining that the impedance of the resonant circuit has changed from a threshold or setpoint impedance; and restoring the threshold or setpoint impedance by modifying the frequency of the charging current. The resonant circuit may include the charging coil.

Description

[0001] Priority requirements

[0002] This application claims priority and benefit to U.S. Patent Application No. 62 / 957,420, filed January 6, 2020, and U.S. Provisional Patent Application No. 62 / 957,420, filed January 6, 2020, both of which are incorporated herein by reference in their entirety as if fully set forth herein and used for all applicable purposes. Technical Field

[0003] The present invention generally relates to wireless charging of batteries, including using a multi-coil wireless charging device to charge batteries in mobile devices, regardless of the position of the mobile device on the surface of the multi-coil wireless charging device. Background Technology

[0004] Wireless charging systems have been deployed to enable certain types of devices to charge their internal batteries without using a physical charging connection. Devices that can utilize wireless charging include mobile processing and / or communication devices. Standards such as the Qi standard defined by the Wireless Power Association enable devices manufactured by a first-party supplier to be wirelessly charged using chargers manufactured by a second-party supplier. Wireless charging standards are optimized for relatively simple device configurations and tend to provide basic charging capabilities.

[0005] Improvements in wireless charging capabilities are needed to support the increasing complexity and variability of mobile devices. For example, improved charging technologies are required for multi-coil, multi-device charging pads. Attached Figure Description

[0006] Figure 1 An example of a charging unit that can be used to provide a charging surface according to certain aspects disclosed herein is shown.

[0007] Figure 2 An example is shown of an arrangement of multiple charging units disposed on a single layer of a section of a charging surface that may be applicable to certain aspects disclosed herein.

[0008] Figure 3 An example of an arrangement of multiple charging units is shown, which can be adapted to certain aspects disclosed herein, when multiple layers are covered within a section of a charging surface.

[0009] Figure 4 The arrangement of the power transmission area provided by the charging surface is shown, which employs a multi-layer charging unit configured according to certain aspects disclosed herein.

[0010] Figure 5A wireless transmitter that may be provided in a charger base station according to certain aspects disclosed herein is shown.

[0011] Figure 6 A first topology supporting matrix multiplexing switching is shown in a wireless charging device applicable in accordance with certain aspects disclosed herein.

[0012] Figure 7 A second topology for supporting DC current drive in wireless charging devices is shown, which is applicable according to certain aspects disclosed herein.

[0013] Figure 8 A wireless transmitter provided in accordance with certain aspects disclosed herein is shown.

[0014] Figure 9 A first example of the impedance characteristics of a resonant circuit applicable to certain aspects disclosed herein is shown.

[0015] Figure 10 A continuously tunable wireless transmitter is shown, provided in accordance with certain aspects disclosed herein.

[0016] Figure 11 A second example of the impedance characteristics of a resonant circuit applicable to certain aspects disclosed herein is shown.

[0017] Figure 12 Examples of control circuits applicable to certain aspects disclosed herein are shown.

[0018] Figure 13 This is a flowchart illustrating an example of a method for detecting an object performed by a controller provided in a wireless charging device applicable according to certain aspects disclosed herein.

[0019] Figure 14 An example of an apparatus employing processing circuitry applicable to certain aspects disclosed herein is shown. Detailed Implementation

[0020] The detailed descriptions described below, taken in conjunction with the accompanying drawings, are intended as a description of various configurations, and not as representations of only configurations in which the concepts described herein can be practiced. The detailed descriptions include specific details used to provide a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some cases, well-known structures and components are shown in block diagram form to avoid obscuring these concepts.

[0021] Several aspects of a wireless charging system will now be presented with reference to various devices and methods. These devices and methods will be described in detail below and illustrated in the accompanying drawings by various boxes, modules, components, circuits, steps, processes, algorithms, etc. (collectively, “elements”). These elements can be implemented using electronic hardware, computer software, or any combination thereof. Whether these elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the entire system.

[0022] As an example, an element, or any part thereof, or any combination thereof, may be implemented using a “processing system” comprising one or more processors. Examples of processors include microprocessors, microcontrollers, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gating logic, discrete hardware circuitry, and other suitable hardware configured to perform the various functionalities described throughout this invention. One or more processors in the processing system may execute software. Software should be interpreted broadly as instructions, instruction sets, code, code segments, program code, programs, subroutines, software modules, application programs, software applications, software packages, routines, subroutines, objects, executable programs, threads of execution, procedures, functions, etc., whether or not referred to as software, firmware, middleware, microcode, hardware description languages, etc. Software may reside on processor-readable storage media. Processor-readable storage media (also referred to herein as computer-readable media) may include, for example, magnetic storage devices (e.g., hard disks, floppy disks, magnetic stripes), optical discs (e.g., compact discs (CDs), digital multifunction discs (DVDs)), smart cards, flash memory devices (e.g., cards, sticks, key drives), near-field communication (NFC) tokens, random access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), registers, removable disks, carrier waves, transmission lines, and any other suitable media for storing or transmitting software. Computer-readable media may reside in a processing system, be external to the processing system, or be distributed across multiple entities including the processing system. Computer-readable media may embody a computer program product. As an example, a computer program product may include computer-readable media within packaging material. Those skilled in the art will recognize that how best to implement the functionality described throughout this invention depends on the specific application and the overall design constraints imposed on the system as a whole.

[0023] Certain aspects of the present invention relate to systems, apparatuses, and methods suitable for wireless charging devices that provide a freely locating charging surface having multiple transmitting coils or capable of simultaneously charging multiple receiving devices. In one aspect, a controller in the wireless charging device can locate a device to be charged and configure one or more transmitting coils for optimal positioning to transmit power to the receiving devices. Charging units may be equipped with or configured with one or more inductive transmitting coils, and multiple charging units may be arranged or configured to provide the charging surface. The location of the device to be charged can be detected by sensing techniques that correlate the location of the device with changes in physical characteristics concentrated at a known location on the charging surface. In some examples, location sensing may be implemented using capacitive, resistive, inductive, touch, pressure, load, strain, and / or another suitable type of sensing.

[0024] Some aspects disclosed herein relate to improved wireless charging technology. Systems, apparatus, and methods for freely placing rechargeable devices on the surface of a multi-coil wireless charging device are disclosed. Certain aspects can improve the efficiency and capacity of wireless power transmission to the receiving device. In one example, the wireless charging device includes: a battery charging power supply; a plurality of charging units configured as a matrix; a first plurality of switches, wherein each switch is configured to connect a row of coils in the matrix to a first terminal of the battery charging power supply; and a second plurality of switches, wherein each switch is configured to connect a column of coils in the matrix to a second terminal of the battery charging power supply. Each of the plurality of charging units may include one or more coils surrounding a power transmission region. The plurality of charging units may be arranged adjacent to the charging surface, and the power transmission regions of the charging units in the plurality of charging units do not overlap.

[0025] In one aspect of the invention, the device has a battery charging power source and a plurality of charging units, wherein a controller can select and connect each charging unit to the power source as needed or desired. Each of the plurality of charging units may include one or more coils surrounding a power transmission area. The plurality of charging units may be arranged adjacent to a charging surface without overlap of the power transmission areas of the charging units.

[0026] Certain aspects of the present invention relate to systems, apparatus, and methods for wireless charging using multiple coil stacks that can charge a target device presented to a charging device without needing to match a specific geometry or position within the charging surface of the charging device. Each coil can have a substantially polygonal shape. In one example, each coil can have a hexagonal shape. Each coil can be implemented using wires provided in a helical form, printed circuit board traces, and / or other connectors. Each coil can span two or more layers separated by an insulator or substrate, such that the coils in the different layers are centered on a common axis.

[0027] According to certain aspects disclosed herein, power can be wirelessly transmitted to a receiving device located anywhere on a charging surface, the receiving device having any defined size or shape, regardless of any separate placement location suitable for charging. Multiple devices can be charged simultaneously on a single charging surface. The charging surface can be manufactured using printed circuit board technology in a low-cost and / or compact design.

[0028] Certain aspects of the present invention relate to systems, apparatuses, and methods suitable for wireless charging devices that provide a freely locating charging surface having multiple transmitting coils or capable of simultaneously charging multiple receiving devices. In one aspect, processing circuitry coupled to the freely locating charging surface can be configured to locate the device to be charged and can select and configure optimal positioning to send power to one or more transmitting coils of the receiving device. Charging units can be configured to have one or more inductive transmitting coils, and multiple charging units can be arranged or configured to provide the charging surface. The location of the device to be charged can be detected by sensing techniques that correlate the location of the device with changes in physical characteristics concentrated at a known location on the charging surface. In some examples, location sensing can be implemented using capacitive, resistive, inductive, touch, pressure, load, strain, and / or another suitable type of sensing.

[0029] According to certain aspects disclosed herein, a charging surface can be provided using charging units deployed adjacent to the charging surface. In one example, the charging units are deployed according to a cellular packaging configuration. A charging unit can be implemented using one or more coils, each coil capable of inducing a magnetic field along an axis substantially orthogonal to the charging surface of its neighboring coil. In this disclosure, a charging unit can refer to an element having one or more coils, wherein each coil is configured to generate an electromagnetic field that is additive with respect to the fields generated by other coils in the charging unit and is guided along or near a common axis. In this specification, the coils in a charging unit can be referred to as charging coils or transmitting coils.

[0030] In some implementations, the charging unit includes coils stacked along a common axis. One or more coils may overlap such that they contribute to an induced magnetic field substantially perpendicular to the charging surface. In some examples, a charging unit includes multiple coils arranged within a defined portion of the charging surface and contributing to an induced magnetic field within that defined portion, which in turn contributes to a magnetic flux flowing substantially perpendicular to the charging surface. In some implementations, the charging unit can be configured by providing an activation current to the coils included in a dynamically defined charging unit. For example, a wireless charging device may include multiple stacks of coils deployed on a charging surface, and the wireless charging device may detect the location of a device to be charged and select a combination of multiple stacks of coils to provide a charging unit adjacent to the device to be charged. In some cases, the charging unit may include a single coil, or be characterized as a single coil. However, it should be understood that a charging unit may include multiple stacked coils and / or multiple adjacent coils or multiple stacks of coils.

[0031] Figure 1 An example of a charging unit 100 that can be deployed or configured to provide a charging surface in a wireless charging device is shown. In this example, the charging unit 100 has a substantially hexagonal shape that surrounds one or more coils 102 constructed using conductors, wires, or circuit board traces, which can receive current sufficient to generate an electromagnetic field in a power transmission region 104. In various implementations, some coils 102 may have a substantially polygonal shape, including... Figure 1 The hexagonal charging unit 100 is shown in the figure. Other embodiments may include or use coils 102 with other shapes. The shape of the coil 102 may be determined at least in part by the capabilities or limitations of the manufacturing technology, or to optimize the layout of the charging unit on a substrate 106 such as a printed circuit board substrate. Each coil 102 may be implemented using connectors with wires, printed circuit board traces, and / or other helical structures. Each charging unit 100 may span two or more layers separated by an insulator or substrate 106, such that the coils 102 in the different layers are centered around a common axis 108.

[0032] Figure 2 An example of an arrangement 200 is shown, in which multiple charging units 202 are provided on a single layer in a segment or portion of a charging surface, an arrangement applicable to certain aspects disclosed herein. The charging units 202 are arranged according to a cellular packaging configuration. In this example, the charging units 202 are arranged end-to-end without overlap. This arrangement can be provided without vias or wire interconnections. Other arrangements are also possible, including those in which some portions of the charging units 202 overlap. For example, the wires of two or more coils may be interlaced to some extent.

[0033] Figure 3 An example arrangement of charging cells from two viewpoints 300, 310 is shown, applicable to certain aspects disclosed herein, when multiple layers cover a segment or portion of a charging surface. Charging cell layers 302, 304, 306, 308 are disposed within the charging surface. The charging cells within each charging cell layer 302, 304, 306, 308 are arranged according to a cellular packaging configuration. In one example, the charging cell layers 302, 304, 306, 308 may be formed on a printed circuit board having four or more layers. The arrangement of the charging cells 100 can be selected to provide complete coverage of a designated charging area adjacent to the illustrated segment.

[0034] Figure 4 The arrangement of power transmission areas in a charging surface 400 is shown, which employs a multi-layer charging unit configured according to certain aspects disclosed herein. The charging surface shown consists of four layers of charging units 402, 404, 406, and 408. Figure 4 In this configuration, each power transmission area provided by the charging unit in the first layer charging unit 402 is labeled "L1", each power transmission area provided by the charging unit in the second layer charging unit 404 is labeled "L2", each power transmission area provided by the charging unit in the third layer charging unit 406 is labeled "L3", and each power transmission area provided by the charging unit in the fourth layer charging unit 408 is labeled "L4".

[0035] Figure 5 An example of a wireless transmitter 500 that can be provided in a base station of a wireless charging device is shown. The base station in the wireless charging device may include one or more processing circuits for controlling the operation of the wireless charging device. A controller 502 may receive feedback signals filtered or otherwise processed by a filter circuit 508. The controller may control the operation of a driver circuit 504 that supplies alternating current to a resonant circuit 506. In some examples, the controller 502 may generate a digital frequency reference signal for controlling the frequency of the alternating current output by the driver circuit 504. In some cases, a programmable counter or the like may be used to generate the digital frequency reference signal. In some examples, the driver circuit 504 includes a power inverter circuit and one or more power amplifiers that cooperate to generate alternating current from a DC current source or input. In some examples, the digital frequency reference signal may be generated by the driver circuit 504 or by another circuit. The resonant circuit 506 includes a capacitor 512 and an inductor 514. The inductor 514 may represent or include one or more transmitting coils of a charging unit that generate magnetic flux in response to alternating current. The resonant circuit 506 may also be referred to as an energy storage circuit, an LC energy storage circuit, or an LC energy storage circuit in this document, and the voltage 516 measured at the LC node 510 of the resonant circuit 506 may be referred to as the energy storage voltage.

[0036] Passive pinging technology can use voltage and / or current measured or observed at LC node 510 to identify the presence of a receiving coil near the charging pad of a device applicable according to certain aspects of the present invention. Some conventional wireless charging devices include circuitry for measuring the voltage at LC node 510 of resonant circuit 506 or the current in resonant circuit 506. These voltages and currents can be monitored for power regulation purposes and / or to support communication between devices. According to certain aspects of the invention, monitoring... Figure 5 The voltage at LC node 510 in the wireless transmitter 500 shown supports a passive verification technique that can detect the presence of a rechargeable device or other object based on the response of the resonant circuit 506 to a short burst of energy (verification) transmitted through the resonant circuit 506.

[0037] Passive detection techniques can be used to provide fast, low-power detection. Passive acoustic pulses can be generated by driving a network including a resonant circuit 506 with a fast pulse containing a small amount of energy. The fast pulse excites the resonant circuit 506 and causes the network to oscillate at its inherent resonant frequency until the injected energy decays and dissipates. The response of the resonant circuit 506 to the fast pulse can be determined in part by the resonant frequency of the resonant LC circuit. The resonant circuit 506 responds to an initial voltage of = V 0 The response of the passive verification can be determined by the voltage observed at LC node 510. V LC This indicates that:

[0038] (Equation 1)

[0039] When controller 502 or another processor uses digital verification to detect the presence of an object, resonant circuit 506 can be monitored. Digital verification is generated by driving resonant circuit 506 for a period of time. Resonant circuit 506 is a tuned network including the transmitting coil of a wireless charging device. The receiving device can modulate the voltage or current observed in resonant circuit 506 by modifying the impedance presented by its power receiving circuit according to the signaling state of the modulation signal. Controller 502 or other processor then waits for an indication of a data modulation response from the receiving device in the vicinity.

[0040] According to certain aspects disclosed herein, coils in one or more charging units can be selectively activated to provide an optimal electromagnetic field for charging compatible devices. In some cases, coils may be assigned to charging units, and some charging units may overlap with other charging units. An optimal charging configuration can be selected at the charging unit level. In some examples, the charging configuration may include charging units on the charging surface determined to be aligned with or close to the device to be charged. A controller may activate a single coil or a combination of coils based on the charging configuration, which in turn is based on the detection of the location of the device to be charged. In some implementations, the wireless charging device may have driver circuitry that can selectively activate one or more transmitting coils or one or more predetermined charging units during a charging event.

[0041] Figure 6 A first topology 600 supporting matrix multiplexing switching is shown, applicable to wireless charging devices according to certain aspects disclosed herein. The wireless charging device can select one or more charging units 100 to charge a receiving device. Unused charging units 100 can be disconnected from current flow. Figure 2 and Figure 3 The illustrated cellular packaging structure can utilize a relatively large number of charging units 100, requiring a corresponding number of switches. According to certain aspects disclosed herein, the charging units 100 can be logically arranged in a matrix 608 having multiple units connected to two or more switches that enable a particular unit to be powered. In the illustrated topology 600, a two-dimensional matrix 608 is provided, where the dimensions can be represented by X and Y coordinates. Each of the first set of switches 606 is configured to selectively connect a first terminal of each unit in a row of units to a first terminal of a voltage or current source 602, which provides current to activate coils in one or more charging units during wireless charging. Each of the second set of switches 604 is configured to selectively connect a second terminal of each unit in a row of units to a second terminal of the voltage or current source 602. When both terminals of a unit are connected to the voltage or current source 602, the charging unit is activated.

[0042] The use of matrix 608 can significantly reduce the number of switching components required to operate a network of tuned LC circuits. For example, N individually connected units require at least N switches, while a two-dimensional matrix 608 with N units can be operated using only a few switches. The use of matrix 608 can result in significant cost savings and reduced circuit and / or layout complexity. In one example, a 9-unit implementation can be implemented in a 3×3 matrix 608 using 6 switches, saving 3 switches. In another example, a 16-unit implementation can be implemented in a 4×4 matrix 608 using 8 switches, saving 8 switches.

[0043] During operation, at least two switches are closed to actively connect a coil or charging unit to voltage or current source 602. Multiple switches may be closed simultaneously to connect multiple coils or charging units to voltage or current source 602. For example, multiple switches may be closed to enable an operating mode that drives multiple transmitting coils when sending power to a receiving device.

[0044] Figure 7 A second topology 700 according to certain aspects disclosed herein is shown, wherein each individual coil or charging unit is directly driven by a driver circuit 702. The driver circuit 702 can be configured to select one or more coils or charging units 100 from a set of coils 704 to charge a receiving device. It should be understood that the concepts disclosed herein regarding charging units 100 can be applied to selectively activating individual coils or multiple sets of coils. Unused charging units 100 do not receive current flow. A relatively large number of charging units 100 can be used, and a switching matrix can be employed to drive individual coils or multiple sets of coils. In one example, a first switching matrix can be configured to define the connections of charging units or a set of coils to be used during a charging event, and a second switching matrix can be used to activate charging units and / or a selected set of coils.

[0045] Some aspects disclosed herein relate to tuned networks comprising one or more capacitors and one or more inductors. Tuned networks can be used in charging systems where a base station is electromagnetically coupled to a receiving device. The network can be tuned to optimize power delivery to enable communication between the base station and the receiving device or to enable the base station to detect the presence of the receiving device. Some wireless charging devices and power supplies are designed to maintain a constant setpoint, wherein this setpoint can define the level of power, current, or voltage.

[0046] Certain aspects of the present invention provide techniques that can be used in wireless charging devices to maintain or preserve the performance of circuits employing tuned circuitry. Figure 8A wireless transmitting circuit 800 provided in a base station of a wireless charging device is shown, wherein the wireless transmitting circuit 800 can connect a driver 804 to one or more coils 812a, 812b, 812c of a resonant circuit 806 during charging and / or detection operations. In one example, each coil 812a, 812b, 812c corresponds to a transmitting coil activated by a charging configuration. In another example, each coil 812a, 812b, 812c represents a charging unit selected by a charging configuration to transmit power. The illustrated example shows three coils 812a, 812b, 812c, but it should be understood that a greater number of coils can be selected or influenced by the charging configuration. The coils 812a, 812b, 812c connected to the driver 804 can be selected to provide a charging configuration optimized to facilitate the transmission of power to a receiving device positioned on a charging surface. In the example shown, the resonant circuit 806 is configured with a set of switches 814a, 814b, and 814c, which allow each coil 812a, 812b, and 812c to be selectively connected via capacitor 808 to a charging current source 810 provided by driver 804. The impedance of the resonant circuit 806 is determined by a nominal capacitance (C). res The capacitor 808 and the connecting coils 812a, 812b, and 812c are used to define the circuit. In the example shown, each of the coils 812a, 812b, and 812c has a nominal inductance (L). res The impedance of the resonant circuit 806 varies with the number of coils 812a, 812b, 812c connected to the driver 804. Therefore, the resonant circuit 806, which is tuned when including the capacitor 808 and one or more coils 812a, 812b, 812c, is detuned when the number of coils 812a, 812b, 812c changes.

[0047] In some aspects of the invention, table-based dynamic tuning can be used when the configuration of the resonant circuit 806 changes. The resonant frequency of the tuned resonant circuit 806 can be changed when an additional inductor is switched into it. When the frequency of the charging current 810 is tuned to match the resonant frequency of the resonant circuit 806, the power transmission level or efficiency of the wireless transmission circuit 800 can be optimized, and this optimization can be maintained by retuning the frequency of the charging current 810 after the frequency of the resonant circuit 806 has changed. A setpoint associated with the wireless transmission circuit 800 can be maintained by adjusting the frequency of the charging current 810 to obtain desired or specified levels of power, current, and / or voltage.

[0048] The frequency of the charging current 810 may be referred to herein as the operating point. The operating point can be selected using a lookup table that associates the frequency with the number, type, and / or identity of the coils included in the resonant circuit 806. In one example, the lookup table can associate the frequency with a known value of the inductance associated with each coil included in the resonant circuit 806. The use of the lookup table can maintain a nearly constant output from the power supply of the wireless transmitting circuit 800. For example, the lookup table can provide information that allows the controller 802 or another processor to change the frequency of the charging current 810 supplied by the driver 804 while changing the coil configuration.

[0049] Figure 9 Figure 900 illustrates the impedance characteristics 902, 904 of two configurations of the resonant circuit 806, wherein the configurations include different numbers of coils 812a, 812b, 812c. The resonant circuit 806 can be designed to have a setpoint obtained when the resonant circuit 806 has a nominal or optimal impedance 910. Impedance characteristics 902, 904 show that the impedance is a function of the frequency of the charging current 810 and also varies with the resonant frequency. When the configuration of the resonant circuit 806 is changed, the controller 802 can change the frequency of the charging current 810 to obtain the nominal or optimal impedance 910. In implementations where a finite or finite number of configurations of the resonant circuit 806 are available, a lookup table can be used to define the frequency of the charging current 810 for each configuration of the resonant circuit 806. The frequencies recorded in the table can be obtained during the initial configuration at device assembly or manufacturing, and / or can be updated or calibrated during operation of the wireless transmitting circuit 800. The lookup table-based approach can be used to achieve fast and low-overhead tuning between operating points 906, 908.

[0050] According to certain aspects of this disclosure, in some implementations the resonant circuit 806 can be continuously tuned. Figure 10 A continuously tunable wireless transmitter 1000 installed in a base station of a wireless charging device is shown, and Figure 11 Figure 1100 shows impedance characteristics 1102 and 1104, corresponding to two different configurations of the resonant circuit 806 and / or the configuration of the resonant circuit 806 affected by the location differences of the power receiving devices connected to the resonant circuit 806. Figure 11 In this circuit, the resonant circuit 806 transitions from a first operating point 1106 to a second operating point 1108. The transition between operating points 1106 and 1108 can be caused by a change in the number of activated coils 812a, 812b, and 812c in the resonant circuit 806 and / or by the repositioning of the receiving device that affects the electromagnetic connection between the resonant circuit 806 and the receiving device.

[0051] The continuously tunable wireless transmitter 1000 includes an additional feedback loop 1002. Figure 8 The components of the wireless transmission circuit 800 are described. In one example, feedback loop 1002 operates as a current-sensing feedback loop, which enables driver 804 or controller 802 to monitor power transfer as indicated by the current flowing through resonant circuit 806. Driver 804 or controller 802 can adjust operating points 1106, 1108 to track changes in the impedance of resonant circuit 806. In one example, changes in the impedance of resonant circuit 806 are tracked by incrementally adjusting the frequency of charging current 810.

[0052] The driver 804 or controller 802 may include or implement proportional-integral-derivative (PID) tuning. PID tuning can be implemented using a control loop including current sensing feedback 1002. The driver 804 or controller 802 can continuously calculate an error value as the difference between the desired setpoint of the current flowing in the resonant circuit 806 and the measured current flowing in the resonant circuit 806, as indicated by the current sensing feedback 1002. The driver 804 or controller 802 can apply a correction calculated as a combination of proportional, integral, and derivative values ​​(referred to as P, I, and D values, respectively).

[0053] PID-based dynamic tuning can be implemented as a PID loop enabled after and / or during a configuration change of the resonant circuit 806. A sufficiently fast PID loop can run freely and apply changes without adding delay. In some cases, the PID loop implemented by the driver 804 or controller 802 may not respond quickly enough to changes in the configuration of the resonant circuit 806, and a transition period can be added to gradually change the configuration from one operating point to another. In one example, pulse width modulation applied to switches 814a, 814b, 814c or a delay introduced via switches 814a, 814b, 814c that switch through a linear operating mode transition can be used.

[0054] Figure 12An example of a PID control circuit 1200 is shown. A defined setpoint 1202 and current sensing feedback 1204 are received and combined to obtain an error value 1206 provided to the PID processor 1208. The PID processor 1208 generates a control signal 1210, which controls a frequency generator 1212 to provide the charging current 810. Timing diagram 1220 shows the gradual change in the frequency of the charging current 810 when the driver 804 or controller 802 cannot respond quickly enough to a change in the configuration of the resonant circuit 806. It should be understood that other control circuits and / or algorithms can be used, including systems employing controllers based on Prandtl-Ishlinskii (PI) hysteresis, for example. The type of control loop used is selected based on system requirements or specifications.

[0055] Figure 13 This is a flowchart 1300 illustrating an example of a method for operating a wireless charging device. The method can be performed by a controller disposed in the wireless charging device. In block 1302, the controller can provide a charging current to a first charging coil in the surface of the wireless charging device. In block 1304, the controller can determine that the impedance of the resonant circuit has changed from a threshold or setpoint impedance. The resonant circuit may include the first charging coil. In block 1306, the controller can restore the threshold or setpoint impedance by modifying the frequency of the charging current.

[0056] In some implementations, the controller can connect a second charging coil to the resonant circuit. The controller can supply charging current to the second charging coil. The connection of the second charging coil can modify the impedance of the resonant circuit. The controller can use a lookup table to determine the frequency of the charging current to be used after the second charging coil is connected to the resonant circuit.

[0057] In some implementations, the controller can disconnect the second charging coil from the resonant circuit. Disconnecting the second charging coil modifies the impedance of the resonant circuit. The controller can use a lookup table to determine the frequency of the charging current to be used after the second charging coil is disconnected from the resonant circuit.

[0058] In one example, the impedance of the resonant circuit is modified by changing the position of the receiving device on the surface of the wireless charging device.

[0059] In some implementations, the controller can detect changes in the monitoring current flowing in the resonant circuit and determine that the impedance of the resonant circuit has changed based on these changes. The controller can receive a feedback signal representing the change in the monitoring current and can use this feedback signal to control the frequency of the charging current. Controlling the frequency of the charging current can include incrementally adjusting the frequency until the impedance of the resonant circuit matches a threshold or setpoint impedance. Controlling the frequency of the charging current can also include delaying the frequency of modification of the charging current.

[0060] Figure 14 Examples of hardware implementations of device 1400 are shown, which may be incorporated into a wireless charging device or a receiving device that enables a battery to be wirelessly charged. In some examples, device 1400 may perform one or more of the functions disclosed herein. According to various aspects of the invention, processing circuitry 1402 may be used to implement any elements or any portion of elements or any combination of elements disclosed herein. Processing circuitry 1402 may include one or more processors 1404 controlled by some combination of hardware and software modules. Examples of processors 1404 include microprocessors, microcontrollers, digital signal processors (DSPs), SOCs, ASICs, field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, sequencers, gating logic, discrete hardware circuitry, and other suitable hardware configured to perform the various functionalities described throughout the invention. One or more processors 1404 may include dedicated processors that perform specific functions and can be configured, expanded, or controlled by one of the software modules 1416. One or more processors 1404 can be configured by a combination of software modules 1416 loaded during initialization, and also by loading or unloading one or more software modules 1416 during operation.

[0061] In the illustrated example, processing circuitry 1402 may be implemented with a bus architecture, typically represented by bus 1410. Bus 1410 may include any number of interconnect buses and bridges, depending on the specific application and overall design constraints of processing circuitry 1402. Bus 1410 connects various circuits including one or more processors 1404 and memory 1406 together. Memory 1406 may include memory devices and mass storage devices, and may be referred to herein as computer-readable media and / or processor-readable media. Memory 1406 may include transient storage media and / or non-transient storage media.

[0062] Bus 1410 can also link various other circuits, such as timing sources, timers, peripheral devices, voltage regulators, and power management circuits. Bus interface 1408 provides an interface between bus 1410 and one or more transceivers 1412. In one example, transceivers 1412 may be provided to enable device 1400 to communicate with charging or receiving devices according to standard-defined protocols. Depending on the nature of device 1400, a user interface 1418 (e.g., keypad, display, speaker, microphone, joystick) may also be provided, and user interface 1418 may be directly or communicatively connected to bus 1410 via bus interface 1408.

[0063] Processor 1404 may be responsible for managing bus 1410 and may include general processing of software stored in a computer-readable medium, which may include memory 1406. In this regard, processing circuitry 1402 including processor 1404 may be used to implement any of the methods, functions, and techniques disclosed herein. Memory 1406 may be used to store data manipulated by processor 1404 when executing software, and said software may be configured to implement any of the methods disclosed herein.

[0064] One or more processors 1404 in the processing circuitry 1402 can execute software. Software should be interpreted broadly as instructions, instruction sets, code, code segments, program code, programs, subroutines, software modules, application programs, software applications, software packages, routines, subroutines, objects, executable programs, threads of execution, procedures, functions, algorithms, etc., regardless of whether it is referred to as software, firmware, middleware, microcode, hardware description languages, or otherwise. The software may reside in a computer-readable form in memory 1406 or on an external computer-readable medium. External computer-readable media and / or memory 1406 may include non-transient computer-readable media. Non-transitory computer-readable media include, for example, magnetic storage devices (e.g., hard disks, floppy disks, magnetic stripes), optical discs (e.g., compact discs (CDs) or digital versatile discs (DVDs)), smart cards, flash memory devices (e.g., "flash drives," card, stick, or key drives), RAM, ROM, programmable read-only memory (PROM), erasable PROMs including EEPROMs (EPROMs), registers, removable disks, and any other suitable media for storing software and / or instructions accessible and readable by a computer. As an example, computer-readable media and / or memory 1406 may also include carrier waves, transmission lines, and any other suitable media for transmitting software and / or instructions accessible and readable by a computer. Computer-readable media and / or memory 1406 may reside in processing circuitry 1402, in processor 1404, outside of processing circuitry 1402, or distributed across multiple entities including processing circuitry 1402. Computer-readable media and / or memory 1406 may be included in a computer program product. For example, a computer program product may include computer-readable media in packaging material. Those skilled in the art will recognize how best to implement the functionality described throughout this invention, depending on the specific application and the overall design constraints imposed on the system as a whole.

[0065] Memory 1406 can maintain and / or organize software in loadable code segments, modules, applications, programs, etc., some or all of which may be referred to herein as software modules 1416. Each software module 1416 may include instructions and data that contribute to a runtime image 1414 controlling the operation of one or more processors 1404 when installed or loaded onto processing circuitry 1402 and executed by one or more processors 1404. When executed, certain instructions may cause processing circuitry 1402 to perform functions according to certain methods, algorithms, and procedures described herein.

[0066] Some software modules 1416 may be loaded during the initialization of the processing circuitry 1402, and these software modules 1416 may configure the processing circuitry 1402 to perform the various functions disclosed herein. For example, some software modules 1416 may configure the internal devices and / or logic circuitry 1422 of the processor 1404 and manage access to external devices (e.g., transceiver 1412, bus interface 1408, user interface 1418, timers, math coprocessors, etc.). Software modules 1416 may include control programs and / or operating systems that interact with interrupt handlers and device drivers and control access to various resources provided by the processing circuitry 1402. Resources may include memory, processing time, access to the transceiver 1412, user interface 1418, etc.

[0067] The processing circuitry 1402 may include one or more processors 1404 that can be multifunctional, whereby software modules 1416 are loaded and configured to perform different functions or different examples of the same function. One or more processors 1404 may also be adapted to manage background tasks initiated in response to inputs, such as from user interface 1418, transceiver 1412, and device drivers. To support the performance of multiple functions, one or more processors 1404 may be configured to provide a multitasking environment, whereby each of the multiple functions is implemented as a set of tasks to be served by one or more processors 1404 as needed or desired. In one example, the multitasking environment may be implemented using a time-sharing program 1420 that transfers control of the processors 1404 between different tasks, whereby each task returns control of one or more processors 1404 to the time-sharing program 1420 upon completion of any incomplete operation and / or in response to inputs such as interrupts. When a task has control over one or more processors 1404, the processing circuitry is effectively dedicated to the purposes addressed by the functions associated with the control task. The time-sharing program 1420 may include an operating system, a main loop based on loop transfer control, a function that allocates control over one or more processors 1404 according to the priority of the function, and / or an interrupt-driven main loop that responds to external events by providing control over one or more processors 1404 to the processing function.

[0068] In one example, device 1400 includes or operates as a wireless charging device having a battery charging power supply coupled to a charging circuit, a plurality of charging units, and a controller, the controller being contained within one or more processors 1404. The plurality of charging units can be configured to provide charging surfaces. At least one coil can be configured to guide an electromagnetic field through a charge transfer region of each charging unit.

[0069] The controller can be configured to provide a charging current to a first charging coil in the surface of the wireless charging device, determine that the impedance of the resonant circuit has changed from a threshold or setpoint impedance, and restore the threshold or setpoint impedance by modifying the frequency of the charging current. The resonant circuit may include the first charging coil.

[0070] In some examples, the controller can connect a second charging coil to the resonant circuit and supply charging current to it. The connection of the second charging coil can modify the impedance of the resonant circuit. The controller can use a lookup table to determine the frequency of the charging current to be used after the second charging coil is connected to the resonant circuit.

[0071] In some examples, the controller can disconnect the second charging coil from the resonant circuit. Disconnecting the second charging coil modifies the impedance of the resonant circuit. The controller can use a lookup table to determine the frequency of the charging current to be used after the second charging coil is disconnected from the resonant circuit.

[0072] In one example, the impedance of the resonant circuit is modified by changing the position of the receiving device on the surface of the wireless charging device.

[0073] In some examples, the controller can detect changes in the monitoring current flowing in the resonant circuit and determine that the impedance of the resonant circuit has changed based on these changes. The controller can receive a feedback signal representing the change in the monitoring current and can use this feedback signal to control the frequency of the charging current. Controlling the frequency of the charging current can include incrementally adjusting the frequency of the charging current until the impedance of the resonant circuit matches a threshold or setpoint impedance. Controlling the frequency of the charging current can also include delaying the frequency of the charging current modification.

[0074] In some examples, memory 1406 stores instructions and information, wherein the instructions are configured to cause the controller to provide charging current to a first charging coil in the surface of the wireless charging device, determine that the impedance of the resonant circuit has changed from a threshold or setpoint impedance, and restore the threshold or setpoint impedance by modifying the frequency of the charging current. The resonant circuit may include the first charging coil.

[0075] In some examples, the instruction is configured to cause the controller to connect a second charging coil to the resonant circuit, providing power to the second charging coil. The connection of the second charging coil can modify the impedance of the resonant circuit. The instruction can be configured to cause the controller to use a lookup table to determine the frequency of the charging current to be used after the second charging coil is connected to the resonant circuit.

[0076] In some examples, the instruction is configured to cause the controller to disconnect the second charging coil from the resonant circuit. Disconnecting the second charging coil can modify the impedance of the resonant circuit. The controller can use a lookup table to determine the frequency of the charging current to be used after the second charging coil is disconnected from the resonant circuit.

[0077] In one example, the impedance of the resonant circuit is modified by changing the position of the receiving device on the surface of the wireless charging device.

[0078] In some examples, the instructions are configured to cause the controller to detect changes in the monitored current flowing in the resonant circuit and determine, based on the changes in the monitored current, that the impedance of the resonant circuit has changed. The controller may receive a feedback signal representing a change in the monitored current and may use this feedback signal to control the frequency of the charging current. Controlling the frequency of the charging current may include incrementally adjusting the frequency of the charging current until the impedance of the resonant circuit matches a threshold or setpoint impedance. Controlling the frequency of the charging current may include delaying the modification of the charging current frequency.

[0079] The preceding description is provided to enable those skilled in the art to practice the various aspects described herein. Various modifications to these aspects will readily be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein, but rather to be consistent with the full scope of the language claims, wherein reference to an element in the singular, unless expressly stated otherwise, is not intended to mean “one and only one,” but rather “one or more.” Unless otherwise specifically stated, the term “some” means one or more. All structural and functional equivalents of the elements of the various aspects described throughout this disclosure (which are known to or subsequently become known to those skilled in the art) are expressly incorporated herein by reference and are intended to be covered by the claims. Furthermore, nothing disclosed herein is intended to be offered to the public, whether or not such disclosure is expressly stated in the claims. Claim elements should not be interpreted pursuant to paragraph 6 of 35 U.S.SC §112 unless the element is expressly stated using the phrase “means for…” or, in the case of a method claim, using the phrase “step for…”.

Claims

1. A method for operating a wireless charging device, the method comprising the following steps: Provide charging current to the first charging coil in the surface of the wireless charging device; Determining that the impedance of the resonant circuit has changed from a threshold, wherein the resonant circuit includes the first charging coil; and The threshold is restored by modifying the frequency of the charging current; Connect the second charging coil to the resonant circuit; The charging current is provided to the second charging coil and the first charging coil, wherein connecting the second charging coil modifies the impedance of the resonant circuit; and A lookup table is used to determine the frequency of the charging current to be used after the second charging coil is connected to the resonant circuit.

2. The method according to claim 1, further comprising the following steps: The second charging coil is separated from the resonant circuit, wherein separating the second charging coil modifies the impedance of the resonant circuit.

3. The method according to claim 2, further comprising the following steps: A lookup table is used to determine the frequency of the charging current to be used after the second charging coil is disconnected from the resonant circuit.

4. The method according to any one of claims 1 to 3, wherein, The impedance of the resonant circuit is modified by changing the position of the receiving device on the surface of the wireless charging device.

5. The method according to claim 1, further comprising the following step: Changes in the monitoring current flowing in the resonant circuit are detected; as well as The change in impedance of the resonant circuit is determined based on the change in the monitored current.

6. The method according to claim 5, further comprising the following step: Receive a feedback signal indicating a change in the monitored current; and The feedback signal is used to control the frequency of the charging current.

7. The method according to claim 5 or 6, wherein, The steps for controlling the frequency of the charging current include: The frequency of the charging current is adjusted incrementally until the impedance of the resonant circuit matches the threshold.

8. The method according to claim 5 or 6, wherein, The steps for controlling the frequency of the charging current include: The frequency of the charging current is delayed.

9. A wireless charging device, the wireless charging device comprising: Multiple charging units are disposed on the surface of the wireless charging device; as well as Processor, the processor being configured to: Provide charging current to the first charging coil in the surface of the wireless charging device; It is determined that the impedance of the resonant circuit has changed from a threshold, wherein the resonant circuit includes the first charging coil; The threshold is restored by modifying the frequency of the charging current; Connect the second charging coil to the resonant circuit; The charging current is provided to the second charging coil and the first charging coil, wherein connecting the second charging coil modifies the impedance of the resonant circuit; and A lookup table is used to determine the frequency of the charging current to be used after the second charging coil is connected to the resonant circuit.

10. The wireless charging device according to claim 9, wherein, The processor is configured to: The second charging coil is separated from the resonant circuit, wherein separating the second charging coil modifies the impedance of the resonant circuit.

11. The wireless charging device according to claim 10, wherein, The processor is configured to: A lookup table is used to determine the frequency of the charging current to be used after the second charging coil is disconnected from the resonant circuit.

12. The wireless charging device according to any one of claims 9 to 11, wherein, The impedance of the resonant circuit is modified by changing the position of the receiving device on the surface of the wireless charging device.

13. The wireless charging device according to claim 9, wherein, The processor is configured to: The change in the monitoring current flowing in the resonant circuit is detected; and The change in impedance of the resonant circuit is determined based on the change in the monitored current.

14. The wireless charging device according to claim 13, wherein, The processor is configured to: Receive a feedback signal indicating a change in the monitored current; and The feedback signal is used to control the frequency of the charging current.

15. The wireless charging device according to claim 13 or 14, wherein, The processor is configured to: The frequency of the charging current is adjusted incrementally until the impedance of the resonant circuit matches the threshold.

16. The wireless charging device according to claim 13 or 14, wherein, The processor is configured to: The frequency of the charging current is delayed.

17. A processor-readable storage medium comprising code for the following operations: Provide charging current to the first charging coil in the surface of the wireless charging device; It is determined that the impedance of the resonant circuit has changed from the threshold, where, The resonant circuit includes the first charging coil; The threshold is restored by modifying the frequency of the charging current; Connect the second charging coil to the resonant circuit; The charging current is provided to the second charging coil and the first charging coil, wherein connecting the second charging coil modifies the impedance of the resonant circuit; and A lookup table is used to determine the frequency of the charging current to be used after the second charging coil is connected to the resonant circuit.

18. The processor-readable storage medium of claim 17, further comprising code for the following operations: The second charging coil is separated from the resonant circuit, wherein, Disconnecting the second charging coil modifies the impedance of the resonant circuit.

19. The processor-readable storage medium of claim 18, further comprising code for the following operations: A lookup table is used to determine the frequency of the charging current to be used after the second charging coil is disconnected from the resonant circuit.

20. The processor-readable storage medium according to any one of claims 17 to 19, wherein, The impedance of the resonant circuit is modified by changing the position of the receiving device on the surface of the wireless charging device.

21. The processor-readable storage medium of claim 17, further comprising code for the following operations: The change in the monitoring current flowing in the resonant circuit is detected; and The change in impedance of the resonant circuit is determined based on the change in the monitored current.

22. The processor-readable storage medium of claim 21, further comprising code for the following operations: Receive a feedback signal indicating a change in the monitored current; and The feedback signal is used to control the frequency of the charging current.

23. The processor-readable storage medium of claim 21 or claim 22, wherein the processor-readable storage medium further comprises code for performing the following operations: The frequency of the charging current is adjusted incrementally until the impedance of the resonant circuit matches the threshold.

24. The processor-readable storage medium according to claim 21 or 22, further comprising code for the following operations: The frequency of the charging current is delayed.

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