An increasingly attractive technology for use with battery-powered electronic devices is wireless battery charging. This technology offers an elegant alternative to plug-in charging, where power cords and adapters proliferate with the number of devices in use and make one's living or work space appear untidy. In addition, wireless battery charging eliminates the difficulty of locating a compatible power cord or adapter for each electronic device, and may make devices less prone to damage during recharge.
To wirelessly charge a battery in an electronic device, the device typically is placed on or near a wireless charger, which transmits energy to the device in the form of an electromagnetic wave. A portion of the transmitted energy is received by a power-receiver module installed in the electronic device. The power-receiver module typically includes at least one receiver coil. With the electronic device suitably positioned on or near the wireless charger, the receiver coil couples inductively to a transmitter coil in the wireless charger, which carries an alternating electric current. The alternating magnetic flux from the current in the transmitter coil induces an alternating voltage in the receiver coil. Analog componentry in the power-receiver module serves to convert this voltage to an appropriate level for charging the battery of the electronic device.
In the current state of the art, the power-receiver module also includes digital componentry to communicate with and regulate power transfer from the wireless charger. Distributed on one or more chips, the digital componentry may include a mircrocontroller, instruction memory to store supportive software and/or firmware, and at least some data memory.
The inventors herein have identified numerous disadvantages resulting from the use of dedicated digital componentry in the wireless power-receiver module of an electronic device. In brief, the dedicated digital componentry is redundant in a modern, microprocessor-controlled electronic device. Furthermore, the dedicated digital componentry may be limited functionally at design time, and may be difficult or impossible to update in order to accommodate newer batteries or wireless-chargers as they become available.
Aspects of this disclosure will now be described by example and with reference to the illustrated embodiments listed above. Components, process steps, and other elements that may be substantially the same in one or more embodiments are identified coordinately and are described with minimal repetition. It will be noted, however, that elements identified coordinately may also differ to some degree. It will be further noted that the drawing figures included in this disclosure are schematic and generally not drawn to scale. Rather, the various drawing scales, aspect ratios, and numbers of components shown in the figures may be purposely distorted to make certain features or relationships easier to see.
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Wireless charging of electronic devices offers a number of advantages over conventional charging via a power cord. As noted above, it reduces the number of power cords and adapters that must be kept on hand for use with the devices. In addition, electronic devices that charge without a power cord may be less prone to damage because there is one less wire that can be accidentally tugged on. In the embodiments described herein, the modality of device charging is not only wireless but effectively contactless. In other words, no direct electrical contact is needed between wireless charger 14 and any electronic device 12. In place of direct electrical contact, power-transmitting componentry in the wireless charger is inductively coupled to power-receiving componentry of the electronic device to be charged. This aspect is described below in further detail, with reference to
Wireless charger 14 also includes primary or transmitter coil 22 and transmitter coil driver 24. In the embodiment of
Wireless charger 14 also includes a load-modulation sensor 28 operatively coupled to transmitter coil driver 24. The load-modulation sensor is a communication module configured to sense either the current driven through transmitter coil 22 or a suitable surrogate—e.g., the inductive reactance of the transmitter coil, the phase differential of the current with respect to the voltage, etc. In this manner, the load-modulation sensor is configured to sense the rate of power transfer from the wireless charger to the electronic device being charged. In embodiments in which the power-receiving electronic device communicates to the wireless charger via inductive load modulation, the load-modulation sensor may also be used to demodulate such communication.
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In one embodiment, kernel 50 may be a Linux® kernel. It may include various hardware driver modules: a display driver, a camera driver, a Bluetooth driver, a flash-memory driver, a binder driver, a universal serial bus (USB) driver, a keypad driver, a Wi-Fi driver, and one or more audio drivers, for example. In the illustrated embodiment, kernel 50 also includes a power-management module 60.
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In the illustrated embodiment, this alternating voltage is applied to conditioning module 64, where it is conditioned for use in the electronic device. The conditioning module may rectify the alternating voltage from the receiver coil into a direct voltage. In some examples, the conditioning module may enact high-frequency switching to drive a plurality of direct voltages—e.g., +3.3 volts, −3.3 volts, etc. In some embodiments, the conditioning module may include load-regulating functionality to control how much current is permitted to flow through the receiver coil in response to the alternating voltage induced therein. Such functionality may be embodied as one or more electronically controlled switches or voltage controlled resistances or reactances. In some embodiments, the conditioning module may impart an adjustable capacitance across the receiver coil; the adjustable capacitance may be varied so as to change the phase differential of the current with respect to the induced voltage. Thus, the conditioning module may, in various ways, control the extent of loading of the receiver coil, which determines how much power is extracted from the receiver coil and delivered to downstream componentry of the electronic device.
In some embodiments, the extent of loading of receiver coil 62 may be used as a mode of communication from electronic device 12 to wireless charger 14. To this end, the electronic device of
In embodiments in which wireless charger 14 includes a driver modulator 26 configured to send communications to electronic device 12, the electronic device may include a signal demodulator 68—a communication module configured to demodulate the communication signal embedded in the alternating magnetic flux from transmitter coil 22 (which appears in the form of an induced voltage modulation in receiver coil 62). In this manner, the electronic device may be configured also to receive communication from the wireless charger, as well as to send communication.
In the embodiments emphasized above, communications between wireless charger 14 and the electronic device 12 are exchanged by modulating the magnetic flux shared between transmitter coil 22 of the wireless charger and receiver coil 62 of the electronic device. Although this is an efficient use of system hardware, it does not preclude other modes of communication. For instance, the various other communication modules may be configured to use infrared or Bluetooth communications, or indeed any other suitable mode of data exchange.
In one particular embodiment, the CPU processor core operatively coupled to load modulator 66 and/or signal demodulator 68 may also be configured to provide at least some operating-system and application processing in the electronic device. Machine-readable memory associatively coupled to this processor core may hold instructions that direct the processor core to provide such operating-system and application processing in the electronic device, and to enact various other wireless charging functions as described hereinafter. In brief, the instructions may direct the processor core to compute a set-point condition for wireless energy flow from the wireless charger to the energy-storage component, to regulate the wireless energy flow based on the set-point condition, to control the communication from the communication component, etc. In one embodiment, this processor core may be a low-power processor core—e.g., a companion processor core in a CPU that further includes one or more higher-power, higher-performance processor cores. In this embodiment, the one or more higher-power, higher-performance processor cores may not be configured to participate in computing the set-point condition or in regulating the wireless energy flow. This approach is advantageous because it enables the electronic device to use less power while charging, resulting in overall faster charging and charging from initial states of deeper discharge.
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No aspect of the drawings should be interpreted in a limiting sense, for numerous other configurations lay fully within the spirit and scope of this disclosure. For example, while
The configurations described above enable various methods to store electrical energy in an electronic device. Accordingly, some such methods are now described, by way of example, with continued reference to the above configurations. It will be understood, however, that the methods here described, and others within the scope of this disclosure, may be enabled by different configurations as well. Further, some of the process steps described and/or illustrated herein may, in some embodiments, be omitted without departing from the scope of this disclosure. Likewise, the indicated sequence of the process steps may not always be required to achieve the intended results, but is provided for ease of illustration and description. One or more of the illustrated actions, functions, or operations may be performed repeatedly, depending on the particular strategy being used.
At optional step 76 of method 72, an operational aspect of the wireless charger is identified by the electronic device. The identified aspect may differ in the different embodiments of this disclosure. It may include the power rating, power transmission frequency, duty-cycle, and/or size of the wireless charger, for example. In these and other embodiments, the identified aspect may include the maker and/or model number of the wireless charger. The aspect may be identified via any suitable exchange of data between the electronic device and the wireless charger using the various communication modules described above.
At optional step 78 of method 72, a resource related to electronic-device charging may be downloaded from an external server via a network module of the electronic device. In some embodiments, the resource may take the form of a dedicated application (i.e., ‘app’) or widget. At least two different resource embodiments are envisaged in this disclosure. In one embodiment, the resource is configured to enable the electronic device to be charged at a particular wireless charger or family of wireless chargers, which may differ from the wireless charger that the electronic device was originally intended to work with. In a second embodiment, the resource may be configured to enable a particular energy-storage component in the electronic device to be charged. This component, for example, may be a replacement battery of different electrical characteristics (capacity, impedance, etc.) than the battery originally intended for use with the electronic device. In a related embodiment, the energy-storage component supported by the downloaded resource may not be a replacement per se, but the result of a midstream redesign in production. Naturally, the resource embodiments described herein may be used together. For instance, a given resource may enable a particular energy-storage component in the electronic device to be charged using a particular wireless charger.
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At 82 the charge state of the energy-storage component is modeled. Such modeling may be used in order to compute the optimal voltage or current to be applied to the energy storage component to return it to a fully charged state without causing damage. In one embodiment, the modeling of the charge state may be based on a history of charge and discharge activity in the electronic device. As such the modeling effort may require storage of a significant amount of data, and access to that data during the charging process. Accordingly, it may be advantageous for the modeling to be enacted in a CPU, rather than a microcontroller of limited processing power and access to memory.
At 84 a set-point condition for wireless energy flow from the wireless charger to an energy-storage component of electronic device is computed in the CPU of the electronic device. In one, non-limiting embodiment, the computed set-point condition may be as simple as an ON or OFF condition—e.g., ON indicating that wireless energy flow is desired, OFF indicating that wireless energy flow is not desired. In other embodiments, the computed set-point condition may reflect a desired voltage or current to be applied across the energy-storage component, or a desired power to be received from the wireless charger.
At 86 the wireless energy flow from the wireless charger to the energy storage component is regulated based on the set-point condition. As used herein, the term ‘regulation’ may encompass up-regulation (increasing the rate of energy flow) and/or down-regulation (decreasing the rate of energy flow) as needed to arrive at agreement with the set-point condition. In the various embodiments here contemplated, the CPU itself may be configured to compute the set-point condition for wireless energy flow from the wireless charger to the energy-storage component and to regulate the wireless energy flow based on the set-point condition.
At 86, the amount of power transmitted and/or received (or a suitable surrogate, such as the current drawn though the transmitter coil) may be analyzed via one or more algorithms executed from the CPU. Such algorithms may be used to determine whether a conductive, foreign object (coins, keys, paper clips, foil, etc.) has been inadvertently placed between the transmitter and receiver coils.
The skilled reader will note that in the context of distinguishing a wirelessly chargeable device from adventitious conductive material, it is a great benefit for device communications to be controlled by a sophisticated CPU, rather than a primitive microcontroller. The processing power of the CPU and its associated ecosystem of 10 componentry can enable a more complex, unambiguous reply to be formulated, which is received more reliably by the wireless charger, even in relatively noisy environments and/or various temperatures.
In one embodiment, regulating the wireless energy flow may include controlling an impedance between a receiver coil of the electronic device and the energy-storage component. Thus, the mode of regulation may be internal to the electronic device being charged, and need not involve the cooperation of the charging station. In another embodiment, regulating the wireless energy flow may include sending the wireless charger a request to adjust the wireless energy flow. Thus, the mode of regulation may be at least partly external to the electronic device being charged, requiring the cooperation of the wireless charger. In general, any aspect of the wireless energy flow may be adjusted in this manner—e.g., the amplitude or frequency of the alternating current in the transmitter coil of the wireless charger, or the duty cycle.
No aspect of the foregoing method should be understood in a limiting sense, for numerous variations and extensions are contemplated as well. It will be noted, for example, that the various aspects of method 72—e.g., controlling, computing, and regulating—may be controlled by one or more software programs, and that the above method may also include the act of updating or upgrading the software programs to improve performance, extend functionality, etc. In embodiments in which the electronic device to be charged identifies some aspect of the wireless charger (optional step 76), that aspect may be used to control or influence one or more of the controlling, computing, and regulating actions described hereinabove. In other words, such actions may be modified or adjusted in dependence on the operational aspect identified above. In these and other embodiments, one or more of the controlling, computing, and regulating may be elements of a standard that the electronic device adheres to in the course of accepting power and exchanging communication with the wireless charger. Because the electronic device charging is controlled from the CPU, it is possible for a plurality of standards to be supported by the electronic device. Thus, the standard adhered to may be selected from among a plurality of extant standards, depending on the operational aspect identified.
It will be understood that the configurations and/or approaches described herein are exemplary in nature, and that these specific embodiments or examples are not to be considered in a limiting sense, because numerous variations are possible. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various processes, systems and configurations, and other features, functions, acts, and/or properties disclosed herein, as well as any and all equivalents thereof.