FIELD OF INVENTION
[0001] The present subject matter relates to power management in an electronic device
and, particularly but not exclusively, to power management in an electronic device supporting
charging of an internal power supply of the electronic device through communication interfaces,
such as Universal Serial Bus (USB) interfaces.
BACKGROUND
[0002] Electronic devices, such as mobile phones, personal digital assistants, audio
players, multimedia players, tablets, laptops, Global Positioning System (GPS) navigation
systems, digital cameras, gaming consoles, and personal computers, provide users with a variety
of communications services and/or computer networking capabilities. Usually these electronic
devices have capabilities to synchronize content with other electronic devices, receive content
from other electronic devices, transfer content to other electronic devices, and share content with
other electronic devices over a variety of communication interfaces, ports and protocols, for
example Bluetooth, Wi-Fi, infra-red, Universal Serial Bus (USB) interface and so on. In recent
times, a majority of electronics devices have one or more USB interfaces which facilitate
exchange of data with other electronic devices.
[0003] Further, a USB interface of a first electronic device may be used to charge the
internal power supply of a second electronic device. In said example, the second electronic
device may be coupled to the USB interface of the first electronic device using a data
transmission cable. For example, the internal power supply, i.e. battery, of a mobile phone may
automatically start charging when the mobile phone is connected to the USB interface of another
electronic device, say a laptop.
[0004] In accordance with the USB 1.x and 2.0 specifications, the USB interfaces usually
provide a power supply of five volts with around five percent variance between the positive USB
power line and negative USB power line. The USB 3.0 specifications specify the voltage
supplied by low-powered USB interfaces to be between 4.45 volts and 5.25 V. This facilitates
the charging of an internal power supply of a majority of electronic devices by connecting the
electronic devices to the USB interface of another electronic device.
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SUMMARY
[0005] This summary is provided to introduce concepts related to power management in
electronic devices. This summary is neither intended to identify essential features of the claimed
subject matter nor is it intended for use in determining or limiting the scope of the claimed
subject matter.
[0006] In one embodiment, a method for power management in a first electronic device
supporting charging of an internal power supply of the first electronic device through a
communication interface comprises monitoring a power status of the internal power supply,
determining if the power status of the internal power supply is below a critical power level; and
activating charging of the internal power supply of the first electronic device through the
communication interface on determining the power status of the internal power supply to be
below the critical power level.
[0007] In accordance with another embodiment of the present subject matter, an electronic
device comprises a processor, and a memory coupled to the processor, the memory comprising a
Universal Serial Bus (USB) module configured to detect a connection of the first electronic
device to a second electronic device over a USB interface of the first electronic device. The
electronic device further comprises a power management module configured to monitor a power
status of an internal power supply of the first electronic device; determine if the power status of
the internal power supply is below a critical power level; and activate charging of the internal
power supply of the first electronic device through the USB interface on determining the power
status of the internal power supply to be below the critical power level.
[0008] In accordance with yet another embodiment of the present subject matter, a nontransitory
computer-readable medium having embodied thereon a computer program for
executing a method, wherein the method comprises determining if the power status of the
internal power supply is below a critical power level; and activating charging of the internal
power supply of the first electronic device through the communication interface on determining
the power status of the internal power supply to be below the critical power level.
BRIEF DESCRIPTION OF THE FIGURES
[0009] The detailed description is described with reference to the accompanying figures.
In the figures, the left-most digit(s) of a reference number identifies the figure in which the
reference number first appears. The same numbers are used throughout the figures to reference
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like features and components. Some embodiments of system and/or methods in accordance with
embodiments of the present subject matter are now described, by way of example only, and with
reference to the accompanying figures, in which:
[0010] Figure 1 illustrates components of an electronic device, in accordance with an
embodiment of the present subject matter.
[0011] Figures 2 illustrates an exemplary method for activating and deactivating USB
charging in the electronic device supporting charging of an internal power supply of the
electronic device through a USB interface, in accordance with an embodiment of the present
subject matter.
[0012] Figure 3 illustrates an exemplary method for power management in the
electronic device supporting charging of an internal power supply of the electronic device
through a USB interface, in accordance with an embodiment of the present subject matter.
[0013] It should be appreciated by those skilled in the art that any block diagrams herein
represent conceptual views of illustrative systems embodying the principles of the present
subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state
transition diagrams, pseudo code, and the like represent various processes which may be
substantially represented in computer readable medium and so executed by a computer or
processor, whether or not such computer or processor is explicitly shown.
DESCRIPTION OF EMBODIMENTS
[0014] In the present document, the word "exemplary" is used herein to mean "serving as
an example, instance, or illustration." Any embodiment or implementation of the present subject
matter described herein as "exemplary" is not necessarily to be construed as preferred or
advantageous over other embodiments.
[0015] Systems and methods for power management in an electronic device, supporting
charging of an internal power supply of the electronic device through a Universal Serial Bus
(USB) interface, are described. The systems and methods can be implemented in a variety of
electronic devices. The electronic devices that can implement the described method(s) include,
but are not limited to, mobile phones, personal digital assistants, audio players, multimedia
players, tablets, net-books, note-books, laptops, Global Positioning System (GPS) navigation
systems, digital cameras, gaming consoles, and personal computers, and the like.
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[0016] Conventionally, an electronic device includes various ports and communication
interfaces, such as USB interface, wireless card, Ethernet card, e-Serial Advanced Technology
Attachment (eSATA) port, High-Definition Multimedia Interface (HDMI), Video Graphics
Array (VGA) connector, and Secure Digital (SD) card interface, to facilitate the exchange of data
between the electronic device and other electronic devices, wherein each port and
communication interface work as per standard specifications. Some standards, such as standards
for USB interfaces, provide for supplying power supply to the communication interfaces which
may be used to power up or charge another electronic device connected through the USB
interfaces. Further, many conventional electronic systems also facilitate the charging of an
internal power supply of the electronic device through the USB interface of the electronic device.
For example, a mobile phone when connected to a laptop through the USB interface may charge
its internal power supply by drawing power from the USB interface of the laptop.
[0017] During usage, a user may connect a first electronic device, which supports
charging through the USB interface, to a second electronic device, using the USB interface, for
transferring data. For example, the user may wish to move or copy some files from the first
electronic device to the second electronic device. In another example, the user may wish to
synchronize one or more folders of the first electronic device and the second electronic device. In
many cases, the user may not intend to charge the internal power supply of the first electronic
device every time the user connects the first electronic device to the second electronic device.
This may be because certain categories of internal power supplies complete a charging/
discharging cycle on being connected and subsequently disconnected from a charging point.
Thus the life of the internal power supply of the electronic device may be drastically reduced if
the first electronic device is frequently connected and disconnected from the second electronic
device.
[0018] In another example, the user may not wish to charge the electronic device using
the power supply provided by the second electronic device as the second electronic device may
be running on its own internal power supply. For example, say the user connects his mobile
phone to his laptop, using the USB interface, to access internet on his laptop using the network
connectivity of the mobile phone. In case the laptop is running on its own internal power supply,
i.e. batteries, the uptime of the laptop on its own internal power supply will be reduced if the
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mobile phone draws power from the USB interface of the laptop to charge the internal power
supply of the mobile phone.
[0019] Conventional approaches to control charging of the internal power supply of the
electronic device through the USB interface includes rooting or jail-breaking the electronic
device’s operating system to gain access to the sub-systems of the operating system, such as the
power management module. The power management module of the electronic device is usually
configured to implement various power management schemes, activating or deactivating
charging operations, and so on, However, rooting or jail-breaking the electronic device usually
voids any warranty provided by the manufacturer of the electronic device and hence, has limited
success.
[0020] Another conventional approach to control charging of the internal power supply
of the electronic device through the USB interface includes making changes in the registry of the
electronic device so as to disable power supply to its USB interfaces. However, editing registry
of an electronic device requires a high level of expertise on the part of the user. Moreover, once
the registry settings have been changes, the power supply to USB interfaces may be enabled only
be editing the registry again. This is a time consuming process for the user to do every time he
wants to activate or deactivate USB charging. Further, erroneous changes in the registry may
corrupt the operating system of the electronic device, which may make the electronic device
dysfunctional or lead to loss of data or important system files.
[0021] Moreover, conventional techniques of power management in the electronic device
supporting charging of an internal power supply of the electronic device through a USB interface
do not optimize the activation and deactivation of USB charging of the internal power supply of
the electronic device, based in part on the status of the internal power supply, so as to enhance
the life of the internal power supply and reduce power consumption. For example, conventional
techniques do not enable USB charging on detecting that the electronic device has reached a low
power level nor do they disable USB charging on detecting the electronic device has been
charged to a safe power level.
[0022] The present subject matter pertains to power management in an electronic device
supporting charging of an internal power supply of the electronic device through a USB
interface. In one implementation, the power status of the internal power supply of a first
electronic device may be continuously monitored on being connected to a second electronic
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device over a USB interface. In said implementation, the power status may include remaining
capacity of the internal power supply as a fraction or percentage of full charge capacity of the
internal power supply, projected time for which the first electronic device may be operated on
the internal power supply at a current activity status of the electronic device, etc. The activity
status may be indicative of the rate of power consumption of the first electronic device, which
may be based on the number of applications running on the first electronic device, nature of the
applications running on the first electronic device, display brightness of the first electronic
device, processor speed and clock cycle of the first electronic device and so on.
[0023] When the power status of the internal power supply of the first electronic device
falls below a low power level, say 15% of the full charge capacity of the internal power supply, a
notification is generated for the user, alerting the user to enable USB charging on the first
electronic device. The low power level threshold may be user defined or may be based on a
power management scheme, such as balanced scheme, high-performance scheme, low-power
scheme, and multimedia playback scheme, which is currently active on the first electronic
device. The notification for the user to activate USB charging may be implemented as a display,
for example a pop-up on the screen of the first electronic device, a tone that may be played on
the first electronic device, or a vibration based notification where the first electronic device may
vibrate, to indicate that the first electronic device has reached a low power level threshold.
[0024] If the USB charging is not enabled by the user, the first electronic device
continues to monitor the power status of the internal power supply. When the power status of the
internal power supply of the first electronic device falls below a critical power level, say 5% of
the full charge capacity of the internal power supply, the first electronic device may
automatically activate USB charging of the first electronic device.
[0025] On USB charging being activated, either on user response provided to the
generated notification or the internal power supply reaching a critical power level, the first
electronic device would continue to monitor the power status of the internal power supply. On
the internal power supply being fully charged or reaching a pre-defined safety charge limit, say
50% of the full capacity charge, the first electronic device may be configured to automatically
disable USB charging. In another example, on the internal power supply being fully charged, the
first electronic device may be configured to generate a notification for the user to disable USB
charging.
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[0026] In another implementation, the first electronic device may be configured to
generate a notification to the user to activate or deactivate USB charging on detecting a
connection to the second electronic device through the USB interface. Further, based on the
power scheme activated on the first electronic device or user configuration, the USB charging
may be activated or deactivated by default.
[0027] Thus the electronic device, as described in the present subject matter, facilitates
power management in the electronic device, wherein the electronic device supports charging of
an internal power supply of the electronic device through USB interface. The electronic device
also prevents automatic charging of the internal power supply on being connected to another
electronic device over the USB interface, thus reducing charging/ discharging cycles and
enhancing life of the internal power supply. It should be appreciated by those skilled in the art
that the method and systems explained in the context of USB interfaces may be extended to other
ports and communication interfaces, albeit modifications as would be understood by those
skilled in the art.
[0028] The above methods and system are further described in conjunction with the
following figures. It should be noted that the description and figures merely illustrate the
principles of the present subject matter. It will thus be appreciated that those skilled in the art
will be able to devise various arrangements that, although not explicitly described or shown
herein, embody the principles of the present subject matter and are included within its spirit and
scope. Furthermore, all examples recited herein are principally intended expressly to be only for
pedagogical purposes to aid the reader in understanding the principles of the present subject
matter and the concepts contributed by the inventor(s) to furthering the art, and are to be
construed as being without limitation to such specifically recited examples and conditions.
Moreover, all statements herein reciting principles, aspects, and embodiments of the present
subject matter, as well as specific examples thereof, are intended to encompass equivalents
thereof.
[0029] It will also be appreciated by those skilled in the art that the words during, while,
and when as used herein are not exact terms that mean an action takes place instantly upon an
initiating action but that there may be some small but reasonable delay, such as a propagation
delay, between the initial action and the reaction that is initiated by the initial action.
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Additionally, the word “connected” is used throughout for clarity of the description and can
include either a direct connection or an indirect connection.
[0030] Figure 1 illustrates the exemplary components of an electronic device 100, in
accordance with an embodiment of the present subject matter. In one embodiment, the electronic
device 100 is configured to facilitate the user to implement power management in the electronic
device 100, wherein the electronic device 100 supports charging of an internal power supply of
the electronic device 100 through a charging communication interface, such as an USB based
interface. The electronic device 100 may be implemented as various computing devices, such as
a mobile phone, a smart phone, a personal digital assistant, a digital diary, a tablet, a net-book,
GPS navigation systems, digital cameras, gaming consoles, personal computers, and the like. In
said embodiment, the electronic device 100 includes one or more processor(s) 102, hence forth
referred to as processor 102, and a memory 104 connected to the processor 102. The processor
102 may include microprocessors, microcomputers, microcontrollers, digital signal processors,
central processing units, state machines, logic circuitries and/or any other devices that
manipulate signals and data based on operational instructions. The processor 102 can be a single
processing unit or a number of units, all of which could also include multiple computing units.
Among other capabilities, the processor 102 is configured to fetch and execute computerreadable
instructions stored in the memory 104.
[0031] Functions of the various elements shown in the figures, including any functional
blocks labeled as “processor(s)”, may be provided through the use of dedicated hardware as well
as hardware capable of executing software in association with appropriate software. When
provided by a processor, the functions may be provided by a single dedicated processor, by a
single shared processor, or by a plurality of individual processors, some of which may be shared.
Moreover, explicit use of the term “processor” should not be construed to refer exclusively to
hardware capable of executing software, and may implicitly include, without limitation, digital
signal processor (DSP) hardware, network processor, application specific integrated circuit
(ASIC), field programmable gate array (FPGA), read only memory (ROM) for storing software,
random access memory (RAM), and non volatile storage. Other hardware, conventional and/or
custom, may also be included.
[0032] The memory 104 can include any non-transitory computer-readable medium
known in the art including, for example, volatile memory, such as random access memory
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(RAM) and/or non-volatile memory, such as flash. The memory 104 further includes module(s)
106 and data 108. The computer-readable medium however excludes a transitory, propagating
signal. The module(s) 106 include routines, programs, objects, components, data structures, etc.,
which perform particular tasks or implement particular abstract data types. In one
implementation, the module(s) 106 may include a power management module 110, a USB
application module 112, and other module(s) 114. In one implementation, the power
management module 110 may further include a battery management module 116. The other
module(s) 114 may include programs or coded instructions that supplement applications and
functions of the electronic device 100.
[0033] On the other hand, the data 108, amongst other things, serves as a repository for
storing data processed, received, associated, and generated by one or more of the module(s) 106.
The data 108 includes, for example, operational mode data 118, and power schemes data 120.
The data 108 may also include other data 122.The other data 122 includes data generated as a
result of the execution of one or more modules in the other module(s) 114.
[0034] Further the electronic device 100 includes one or more communication
interface(s) 124. The communication interfaces 124 may include a variety of software and
hardware communication interfaces, for example, USB interfaces 126, communication interfaces
for peripheral device(s), such as data input output devices, referred to as I/O devices, storage
devices, network devices, wireless card interfaces, Ethernet card interfaces, e-Serial Advanced
Technology Attachment (eSATA) port, High-Definition Multimedia Interface (HDMI), Video
Graphics Array (VGA) connector, and Secure Digital (SD) card interface, etc. The
communication interfaces 124 may include their corresponding device drivers. The
communication interface(s) 124 facilitate the communication of the electronic device 100 with
various other electronic devices and various networks, such as Global System for Mobile
Communication (GSM) network, Universal Mobile Telecommunications System (UMTS)
network, Personal Communications Service (PCS) network, Time Division Multiple Access
(TDMA) network, Code Division Multiple Access (CDMA) network, Next Generation Network
(NGN), IP-based network, Public Switched Telephone Network (PSTN), Integrated Services
Digital Network (ISDN), networks that use a variety of protocols, for example, Hypertext
Transfer Protocol (HTTP), Transmission Control Protocol/Internet Protocol (TCP/IP), Wireless
Application Protocol (WAP).
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[0035] In one implementation, the electronic device 100, also referred as the first device
100, may be connected to a second electronic device through one of the communication
interfaces 124, for example, the USB interface 126. The connection of the electronic device 100
with the second electronic device may be done to facilitate data exchange between the electronic
device 100 and the second electronic device, for example data synchronization between the
electronic device 100 and the second electronic device, receive content from the second
electronic device, transfer content to the second electronic device, and share content with the
second electronic device. The present subject matter is being explained in detail in the context of
USB interface 126. A person skilled in the art would however appreciate that same is not a
limitation and the present subject matter may also be implemented using any of the
communication interfaces 124 albeit modifications as would be understood by those skilled in
the art.
[0036] In one implementation, on communicatively coupling the electronic device 100
with the second electronic device, the USB application module 112 may be configured to
generate a menu so as to request input from the user on how to interface the electronic device
100 with a second electronic device. For example, the electronic device 100 may be connected as
a media device or a storage device with respect to the second electronic device. In another
implementation, the electronic device 100 may be accessed from the second electronic device
through a generic or a proprietary personal computer (PC) suite which may have to be preinstalled
on the second electronic device.
[0037] In said implementation, the menu may also prompt the user to activate or
deactivate USB charging mode of the electronic device 100. When the USB charging mode is
activated or active, the electronic device 100 draws power from the USB interface 126 of the
second electronic device to charge an internal power supply, say batteries, of the electronic
device 100. Similarly, when the USB charging mode is deactivated or is inactive, the electronic
device 100 does not draws power from the USB interface 126 of the second electronic device
and hence, does not charge the internal power supply of the electronic device 100.
[0038] In operation, say the user deactivated USB charging of the electronic device 100.
In one implementation, the power management module 110 may be configured to continuously
monitor the power status of the internal power supply of the electronic device 100. The power
status may include remaining fraction or percentage of full charge capacity of the internal power
12
supply, projected time for which the electronic device 100 may be operated on the internal power
supply at a current activity status of the electronic device 100, etc. The activity status may be
indicative of the rate of power consumption of the electronic device 100, which may be based on
the number of applications running on the electronic device 100, nature of the applications
running on the electronic device 100, display brightness of the electronic device 100, processor
speed and clock cycle of the electronic device 100 and so on.
[0039] When the power management module 110 detects that the power status of the
internal power supply of the electronic device 100 is below a pre-defined low power level, say
15% of the full charge capacity of the internal power supply, the power management module 110
may be configured to generate a notification for the user, alerting the user to enable USB
charging on the electronic device 100. The low power level threshold may be user defined or
may be based on a power management scheme, such as balanced scheme, high-performance
scheme, low-power scheme, and multimedia playback scheme, which is currently active on the
electronic device 100, and is saved as power schemes data 120. The power management schemes
may be understood to be various power management plans that may be implemented in the
electronic device 100. For example, in the high-performance scheme, all components of the
electronic device 100 may be operated at their rated capacity, and thus the electronic device 100
may have high power consumption. Similarly, in low power scheme, the components of the
electronic device 100 may be operated at a lower capacity than their rated capacity and thus the
electronic device 100 may consume less power. In one example, the high-performance scheme
may fix 20% of the full charge capacity of the internal power supply as the low power level,
whereas the low power scheme may fix 10% of the full charge capacity of the internal power
supply as the low power level. The notification for the user to activate USB charging may be
generated by the power management module 110 as a display, for example a pop-up on the
screen of the electronic device 100, a tone that may be played on the electronic device 100, or a
vibration based notification where the electronic device 100 may vibrate, to indicate that the
electronic device 100 has reached the low power level threshold.
[0040] If the USB charging is not enabled by the user upon generation of the notification,
the power management module 110 of the electronic device 100 continues to monitor the power
status of the internal power supply. When the power management module 110 detects that the
power status of the internal power supply of the electronic device 100 is below a critical power
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level, say 5% of the full charge capacity of the internal power supply, the power management
module 110 may be configured to automatically activate USB charging of the electronic device
100. In one embodiment, the critical power level threshold may be user defined or may be based
on a power management scheme, such as balanced scheme, high-performance scheme, lowpower
scheme, and multimedia playback scheme, which is currently active on the electronic
device 100, and is saved as power schemes data 120.
[0041] On USB charging being activated, either on user response provided to the
generated notification or the internal power supply reaching a critical power level, the power
management module 110 of the electronic device 100 may be configured to monitor the power
status of the internal power supply. On the internal power supply being fully charged or reaching
a pre-defined safety charge limit, say 50% of the full capacity charge, the power management
module 110 may be configured to automatically disable USB charging. In another example, on
the internal power supply being fully charged or reaching the pre-defined safety charge limit, the
power management module 110 may be configured to generate a notification for the user to
disable USB charging. Further, in one configuration, the pre-defined safety charge limit may be
user defined or may be based on a power management scheme, such as balanced scheme, highperformance
scheme, low-power scheme, and multimedia playback scheme, which is currently
active on the electronic device 100, and is saved as power schemes data 120.
[0042] In another implementation, the power management module 110 further includes
the battery management module 116 which may be configured to override the activation and
deactivation of the USB charging by the power management module 110 so as to enhance the
life of the internal power supply of the electronic device 100. For example, the internal power
supply of the electronic device 100 may be in form of Lithium Polymer (Li-Poly) Batteries,
Lithium Ion (Li-Ion) Batteries, Nickel Cadmium (NiCd) Batteries, and Nickel Metal Hydride
(NiMH) Batteries. Each of these batteries has varied memory effect, varied charging and
recharging cycle which affect the lifetime of the batteries. The battery management module 116,
based on the type of the internal power supply of the electronic device 100, may override the
activation or deactivation of USB charging so as to enhance the overall lifetime of the internal
power supply of the electronic device 100. In one implementation, the information about various
types of internal power supplies, such as batteries, may be saved as the operational data 118.
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[0043] Thus the electronic device 100 provides the user with the flexibility of activating
and deactivating USB charging of the electronic device 100. Further, the electronic device 100
automatically enables USB charging on the power status of the internal power supply of the
electronic device 100 falling below the critical power level and disables USB charging on the
power status of the internal power supply of the electronic device 100 reaching the pre-defined
safety charge limit. Though operations of the electronic device 100 has been described in context
of the USB interface 126, it should be appreciated by those skilled in the art, that the same
concepts may be extended to other communication interfaces 124, such as wireless card
interfaces, Ethernet card interfaces, e-Serial Advanced Technology Attachment (eSATA) port,
High-Definition Multimedia Interface (HDMI), Video Graphics Array (VGA) connector, and
Secure Digital (SD) card interface.
[0044] Figure 2 illustratesan exemplary method 200 for activating and deactivating USB
charging in the electronic device 100, in accordance with an embodiment of the present subject
matter; whereas Figure 3 illustrates an exemplary method 300 for power management in the
electronic device 100 supporting charging of an internal power supply of the electronic device
100 through an communication interface 124, such as the USB interface 126, in accordance with
an embodiment of the present subject matter. The order in which the methods 200 and 300 are
described is not intended to be construed as a limitation, and any number of the described
method blocks can be combined in any order to implement the methods 200 and 300, or an
alternative method. Additionally, individual blocks may be deleted from the methods 200 and
300 without departing from the spirit and scope of the subject matter described herein.
Furthermore, the methods 200 and 300 may be implemented in any suitable hardware, software,
firmware, or combination thereof.
[0045] A person skilled in the art will readily recognize that steps of the methods 200 and
300 can be performed by programmed computers. Herein, some embodiments are also intended
to cover program storage devices, for example, digital data storage media, which are machine or
computer readable and encode machine-executable or computer-executable programs of
instructions, where said instructions perform some or all of the steps of the described the
methods 200 and 300. The program storage devices may be, for example, digital memories,
magnetic storage media, such as a magnetic disks and magnetic tapes, hard drives, or optically
readable digital data storage media. The embodiments are also intended to cover both
15
communication network and electronic devices configured to perform said steps of the
exemplary the methods 200 and 300.
[0046] With reference to method 200 as depicted in Figure 2, as shown in block 202, a
connection of a first electronic device, such as the electronic device 100, with a second electronic
device over a communication interface 124, such as the USB interface 126. In one
implementation, the USB application module 112 may be configured to detect the connection of
the first electronic device 100 with a second electronic device over the USB interface 126.
[0047] As illustrated in block 204, a notification is generated for the user to set USB
charging mode of the first electronic device 100, based in part on the power status of the internal
power supply of the first electronic device 100. In one implementation, the power management
module 110 of the first electronic device 100 may be configured to generate the notification for
the user to set USB charging mode on detecting connection with the second electronic device
over the USB interface 126. In another implementation, the power management module 110 of
the first electronic device 100 may be configured to generate the notification prompting the user
to activate USB charging on detecting the power status of the internal power supply to be below
the pre-defined low power level. In yet another implementation, the power management module
110 of the first electronic device 100 may be configured to generate the notification prompting
the user to deactivate USB charging on detecting the power status of the internal power supply to
be above the safety charge level or to be fully charged. The notification for the user to set USB
charging may be generated by the power management module 110 as a display, for example a
pop-up on the screen of the electronic device 100, a tone that may be played on the electronic
device 100, or a vibration based notification where the electronic device 100 may vibrate, to
indicate that the electronic device 100 has reached the low power level threshold.
[0048] As depicted in block 206, it is determined if the user has already activated USB
charging of the first electronic device 100. In one implementation, the power management
module 110 may be configured to receive the user’s response to the notification from various
user-input mechanisms conventionally known in the art, such as pressing a key of the first
electronic device 100, pressing a sequence of keys of the first electronic device 100, drawing a
pattern on the touch-screen of first electronic device 100, and pressing a soft key on the touchscreen
of the first electronic device 100.
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[0049] If at block 206, the USB charging mode is determined not to be activated, then as
shown in block 208 (the yes branch), a charger of the first electronic device 100 is activated,
wherein the charger is configured to draw power from the second electronic device over the USB
interface 126 and charge the internal power supply of the first electronic device 100.
[0050] If at block 208 the USB charging mode is determined to be activated, then as
shown in block 210 (the no branch), the charger of the first electronic device 100 is deactivated
on the first electronic device 100 reaching a pre-determined safety charge limit. This ensures that
the charger does not draw any power from the second electronic device over the USB interface
126 and charge the internal power supply of the first electronic device 100.
[0051] With reference to method 300 as depicted in Figure 3, as shown in block 302, the
power status of the internal power supply of the first electronic device 100 is monitored at
periodic time intervals. In one implementation, the power management module 110 may be
configured to obtain status of the internal power supply of the first electronic device 100 at
periodic time intervals.
[0052] As depicted in block 304, it is checked whether the power status of the internal
power supply of the first electronic device 100 is below a pre-defined low power level. In one
implementation, the pre-defined low power level may be set as a percentage or fraction of the
full charge capacity of the internal power supply, based in part on the active power management
scheme of the first electronic device 100. In another implementation, the pre-defined low power
level may be set by the user. In one configuration, the power management module 110 may be
configured to determine if the power status of the internal power supply of the first electronic
device 100 is below a pre-defined low power level. As explained previously, the pre-defined low
power level may be based a power scheme that may be currently active on the first electronic
device 100.
[0053] If at block 304, it is determined that the power status of the internal power supply
of the first electronic device 100 is not below a pre-defined low power level, the power
management module 110 continues to obtain status of the internal power supply of the first
electronic device 100 at periodic time intervals as depicted in block 302.
[0054] If at block 304, it is determined that the power status of the internal power supply
of the first electronic device 100 is below a pre-defined low power level, as illustrated at block
306, a notification is generated, prompting the user to set or activate USB charging mode. In one
17
implementation, the power management module 110 of the first electronic device 100 may be
configured to generate the notification for the user to set USB charging mode. As mentioned
earlier, the notification for the user to set USB charging may be generated by the power
management module 110 as a display, for example a pop-up on the screen of the electronic
device 100, a tone that may be played on the electronic device 100, or a vibration based
notification where the electronic device 100 may vibrate, to indicate that the electronic device
100 has reached the low power level threshold.
[0055] At block 308, it is determined if the user has activated USB charging as a
response to the notification. In one implementation, the power management module 110 may be
configured to receive the user’s response to the notification from various user-input mechanisms
conventionally known in the art, such as pressing a key of the first electronic device 100,
pressing a sequence of keys of the first electronic device 100, drawing a pattern on the touchscreen
of first electronic device 100, and pressing a soft key on the touch-screen of the first
electronic device 100, so as to determine if the user has activated USB charging mode.
[0056] If at block 308, it is determined that USB charging mode has not been activated,
then as depicted at block 310 (the no branch), it is determined if the power status of the internal
power supply of the first electronic device 100 is below a pre-defined critical power level. In one
implementation, the pre-defined critical power level may be set as a percentage or fraction of the
full charge capacity of the internal power supply, based in part on the active power management
scheme of the first electronic device 100. In another implementation, the pre-defined critical
power level may be set by the user. In one configuration, the power management module 110
may be configured to determine if the power status of the internal power supply of the first
electronic device 100 is below a pre-defined critical power level.
[0057] If at block 310, it is determined that the power status of the internal power supply
of the first electronic device 100 is not below the pre-defined critical power level, then as shown
in block 312 (the no branch), the power status of the internal power supply of the first electronic
device 100 is monitored at pre-defined time intervals. In one implementation, the power
management module 110 continues to obtain status of the internal power supply of the first
electronic device 100 at periodic time intervals.
[0058] If at block 308 it is determined that the user has activated USB charging mode or
if at block 310 (the yes branch), it is determined that the power status of the internal power
18
supply of the first electronic device 100 is below the pre-defined critical power level, then as
illustrated in block 314, the internal power supply is charged using the power drawn by the USB
interface 126 from the second electronic device. In one implementation, the power management
module 110 may be configured to automatically enable USB charging of the internal power
supply of the first electronic device 100.
[0059] As depicted in block 316, it is determined if the power status of the internal power
supply of the first electronic device 100 is above a safety charge limit. The safety charge limit
may be set as a percentage or fraction of the full charge capacity of the internal power supply,
based in part on the active power management scheme of the first electronic device 100. In
another implementation, the safety charge limit may be set by the user. In one configuration, the
power management module 110 may be configured to determine if the power status of the
internal power supply of the first electronic device 100 is above a safety charge limit.
[0060] If at block 316, it is determined that the power status of the internal power supply
of the first electronic device 100 is not above the safety charge limit, then as shown in block 318,
the power status of the internal power supply of the first electronic device 100 is monitored at
pre-defined time intervals. In one implementation, the power management module 110 continues
to obtain the power status of the internal power supply of the first electronic device 100 at
periodic time intervals.
[0061] If at block 316, it is determined that the power status of the internal power supply
of the first electronic device 100 is above the safety charge limit, then as shown in block 320, the
USB charging mode of the first electronic device 100 is deactivated. In one implementation, the
power management module 110 is configured to deactivate the USB charging mode on
determining the power status of the internal power supply of the first electronic device 100 to be
above the safety charge limit.
[0062] Although implementations for power management in electronic devices
supporting charging of an internal power supply of the electronic device through USB interfaces
have been described in language specific to structural features and/or methods, it is to be
understood that the appended claims are not necessarily limited to the specific features or
methods described. Rather, the specific features and methods are disclosed as exemplary
implementations for power management in electronic devices.

I/ We claim:
1. A method for power management in a first electronic device (100) supporting charging of
an internal power supply of the first electronic device (100) through a communication
interface (124), the method comprising:
monitoring a power status of the internal power supply;
determining if the power status of the internal power supply is below a critical
power level; and
activating charging of the internal power supply of the first electronic device
(100) through the communication interface (124) on determining the power status of the
internal power supply to be below the critical power level.
2. The method as claimed in claim 1, wherein the method further comprises:
determining if the power status of the internal power supply is below a low power
level; and
generating a notification for a user to activate charging of the internal power
supply of the first electronic device (100), through the communication interface (124), on
determining the power status of the internal power supply to be below the low power
level.
3. The method as claimed in claim 2, wherein the critical power level is based in part on at
least one of a power management scheme of the first electronic device (100), and a userdefined
value.
4. The method as claimed in any one of the preceding claims, wherein the communication
interface (124) comprises at least one of a USB interface (126), a communication
interface for a peripheral device, a wireless card interface, an ethernet card interface, an
e-serial advanced technology attachment (eSATA) port, a high-definition multimedia
interface (HDMI), a video graphics array (VGA) connector, and secure digital (SD) card
interface.
5. The method as claimed in claim 1, wherein the method further comprises:
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determining if the power status of the internal power supply is above a safety
charge limit; and
deactivating charging of the internal power supply of the first electronic device
(100) through the communication interface (124) on determining the power status of the
internal power supply to be above the safety charge limit.
6. The method as claimed in claim 5, wherein the safety charge limit is at based in part on at
least one of a power management scheme of the first electronic device (100), and a userdefined
value.
7. The method as claimed in claim 1, wherein the low power level is at based in part on at
least one of a power management scheme of the first electronic device (100), and a userdefined
value.
8. A first electronic device (100) comprising:
a processor (102); and
a memory (104) coupled to the processor (102), the memory (104) comprising,
a Universal Serial Bus (USB) module (112) configured to detect a
connection of the first electronic device (100) to a second electronic device over a
USB interface (126) of the first electronic device (100);
a power management module (110) configured to:
monitor a power status of an internal power supply of the first
electronic device (100);
determine if the power status of the internal power supply is below
a critical power level; and
activate charging of the internal power supply of the first electronic
device (100) through the USB interface (126) on determining the power
status of the internal power supply to be below the critical power level.
9. The first electronic device (100) as claimed in claim 8, wherein the power management
module (110) is further configured to:
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determine if the power status of the internal power supply is below a low power
level; and
generate a notification for a user to activate charging of the internal power supply
of the first electronic device (100) through the USB interface (126) on determining the
power status of the internal power supply to be below the low power level.
10. The first electronic device (100) as claimed in claim 8, wherein the power management
module (110) is further configured to:
determine if the power status of the internal power supply is above a safety charge
limit; and
deactivate charging of the internal power supply of the first electronic device
(100) through the USB interface (126) on determining the power status of the internal
power supply to be above the safety charge limit.
11. The first electronic device (100) as claimed in claim 8, wherein the power management
module (110) further comprises a battery management module (116) configured to
override the activation and deactivation of USB charging by the power management
module (110), based in part on the type of the internal power supply of the first electronic
device (100), to optimize the life of the internal power supply.
12. A non-transitory computer-readable medium having embodied thereon a computer
program for executing a method comprising:
determining if the power status of the internal power supply is below a critical
power level; and
activating charging of the internal power supply of the first electronic device
(100) through the communication interface (124) on determining the power status of the
internal power supply to be below the critical power level.
13. The non-transitory computer-readable medium as claimed in claim 12, wherein the
method further comprises:
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determining if a power status of an internal power supply of a first electronic
device (100) is below a low power level; and
generating a notification for a user to activate charging of the internal power
supply of the first electronic device (100) through a communication interface (124) of the
first electronic device (100) on determining the power status of the internal power supply
to be below the low power level.
14. The non-transitory computer-readable medium as claimed in claim 13, wherein the
method further comprises:
determining if the power status of the internal power supply is above a safety
charge limit; and
deactivating charging of the internal power supply of the first electronic device
(100) through the communication interface (124) on determining the power status of the
internal power supply to be above the safety charge limit