# Patent

## Title
Multi-stage power adapter configured to provide a first power level upon initial connection of the power adapter to the host device and a second power level thereafter upon notification from the host device to the power adapter

## Abstract

Multi-stage power adapter techniques are described in which a power adapter for a device is configured to selectively switch between a relatively low power supply and a relatively high power supply. The low power supply may be employed upon initial connection of the adapter to a host device to ensure that the adapter is safe when disconnected and does not supply full power before the device is ready to receive the high power supply. The low power supply may supply enough power for the host device to detect the connection of the adapter and establish initial communication with the adapter. A switch to the high power supply by the adapter may then occur in response to a notification from the host device that indicates the host device is ready for the high power supply. The switch to high power supply enables normal operation of the host device.

## Background
RELATED APPLICATIONS
This application claims priority under 35 U.S.C. §119(e) to the following U.S. Provisional Patent Applications, the entire disclosures of each of these applications being incorporated by reference in their entirety:
U.S. Provisional Patent Application No. 61/606,333, filed Mar. 2, 2012, and titled “Usage and Authentication;”
U.S. Provisional Patent Application No. 61/613,745, filed Mar. 21, 2012, and titled “Usage and Authentication;” and
U.S. Provisional Patent Application No. 61/607,451, filed Mar. 6, 2012, and titled “Spanaway Provisional.”


BACKGROUND
Mobile computing devices have been developed to increase the functionality that is made available to users in a mobile setting. For example, a user may interact with a mobile phone, tablet computer, or other mobile computing device to check email, surf the web, compose texts, interact with applications, and so on. One challenge that faces developers of mobile computing devices is efficient power management and extension of battery life. For instance, the small form factor of many mobile computing devices may compel designs in which power connections are kept relatively small in size. Accordingly, developers may be further concerned with ensuring that adapters designed for use with such small form power connections are safe and supply the proper amount of power to the device.
SUMMARY
Multi-stage power adapter techniques are described. In one or more embodiments, a power adapter for a device is configured to selectively switch between a relatively low power supply and a relatively high power supply. The low power supply may be employed upon initial connection of the adapter to a host device to ensure that the adapter is safe when disconnected and does not supply full power before the device is ready to receive the high power supply. The low power supply may supply enough power for the host device to detect the connection of the adapter and establish initial communication with the adapter. A switch to the high power supply by the adapter may then occur in response to a notification from the host device that indicates the host device is ready for the high power supply. The switch to high power supply enables normal operation of the host device.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.



BRIEF DESCRIPTION OF THE DRAWINGS
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 use of the same reference numbers in different instances in the description and the figures may indicate similar or identical items. Entities represented in the figures may be indicative of one or more entities and thus reference may be made interchangeably to single or plural forms of the entities in the discussion.
FIG. 1 is an illustration of an environment in an example implementation that is operable to employ the techniques described herein.
FIG. 2 depicts an example implementation of an input device of FIG. 1 as showing a flexible hinge in greater detail.
FIG. 3 depicts an example implementation showing a perspective view of a connecting portion of FIG. 2 that includes mechanical coupling protrusions and a plurality of communication contacts.
FIG. 4 depicts an example power adapter for the computing device of FIG. 1 in greater detail.
FIG. 5 depicts an example procedure in accordance with one or more embodiments.
FIG. 6 depicts another example procedure in accordance with one or more embodiments.
FIG. 7 illustrates an example system including various components of an example device that can be implemented as any type of computing device to implement embodiments of the techniques described herein.



DETAILED DESCRIPTION
Overview
Ensuring that adapters designed for use with such small form power connections of modern host devices are safe and supply the proper amount of power to the device can present challenges. For instance, traditional adapters that supply a constant power level may be dangerous and susceptible to shorting out if exposed connections are contacted inadvertently by a user or object other than the corresponding host device.
Multi-stage power adapter techniques are described in which a power adapter for a device is configured to selectively switch between a relatively low power supply and a relatively high power supply. The low power supply may be employed upon initial connection of the adapter to a host device to ensure that the adapter is safe when disconnected and does not supply full power before the device is ready to receive the high power supply. The low power supply may supply enough power for the host device to detect the connection of the adapter and establish initial communication with the adapter. A switch to the high power supply by the adapter may then occur in response to a notification from the host device that indicates the host device is ready for the high power supply. The switch to high power supply enables “normal” operations of the host device.
In the following discussion, an example environment is first described that may employ the techniques described herein. Example procedures are then described which may be performed in the example environment as well as other environments. Consequently, performance of the example procedures is not limited to the example environment and the example environment is not limited to performance of the example procedures.
Example Operating Environment
FIG. 1 is an illustration of an environment 100 in an example implementation that is operable to employ the techniques described herein. The illustrated environment 100 includes an example of a computing device 102 that is physically and communicatively coupled to an input device 104 via a flexible hinge 106. The computing device 102 may be configured in a variety of ways. For example, the computing device 102 may be configured for mobile use, such as a mobile phone, a tablet computer as illustrated, and so on. Thus, the computing device 102 may range from full resource devices with substantial memory and processor resources to a low-resource device with limited memory and/or processing resources. The computing device 102 may also relate to software that causes the computing device 102 to perform one or more operations.
The computing device 102, for instance, is illustrated as including an input/output module 108. The input/output module 108 is representative of functionality relating to processing of inputs and rendering outputs of the computing device 102. A variety of different inputs may be processed by the input/output module 108, such as inputs relating to functions that correspond to keys of the input device, keys of a virtual keyboard displayed by the display device 110 to identify gestures and cause operations to be performed that correspond to the gestures that may be recognized through the input device 104 and/or touchscreen functionality of the display device 110, and so forth. Thus, the input/output module 108 may support a variety of different input techniques by recognizing and leveraging a division between types of inputs including key presses, gestures, and so on.
In the illustrated example, the input device 104 is configured as a keyboard having a QWERTY arrangement of keys although other arrangements of keys are also contemplated. Further, other non-conventional configurations are also contemplated, such as a game controller, configuration to mimic a musical instrument, and so forth. Thus, the input device 104 and keys incorporated by the input device 104 may assume a variety of different configurations to support a variety of different functionality.
As previously described, the input device 104 is physically and communicatively coupled to the computing device 102 in this example through use of a flexible hinge 106. The flexible hinge 106 is flexible in that rotational movement supported by the hinge is achieved through flexing (e.g., bending) of the material forming the hinge as opposed to mechanical rotation as supported by a pin, although that embodiment is also contemplated. Further, this flexible rotation may be configured to support movement in one direction (e.g., vertically in the figure) yet restrict movement in other directions, such as lateral movement of the input device 104 in relation to the computing device 102. This may be used to support consistent alignment of the input device 104 in relation to the computing device 102, such as to align sensors used to change power states, application states, and so on.
The flexible hinge 106, for instance, may be formed using one or more layers of fabric and include conductors formed as flexible traces to communicatively couple the input device 104 to the computing device 102 and vice versa. This communication, for instance, may be used to communicate a result of a key press to the computing device 102, receive power from the computing device, perform authentication, provide supplemental power to the computing device 102, and so on. The flexible hinge 106 may be configured in a variety of ways, further discussion of which may be found in relation to the following figure.
As further illustrated in FIG. 1 the computing device 102 may include a power controller 112 that implements aspects of multi-stage power adapter techniques described herein. The power controller 112 represents functionality of the computing device to perform various operations for power management. This may include management of different power sources and switching between the sources, implementing a defined and/or selected power management scheme, managing battery life, and so forth. The power controller 112 may also facilitate connections and communications with a power adapter 114 configured to supply power to the device via a suitable power source 116, such as a wall socket, external battery, or other external source of power. The power controller 112 may be implemented in hardware, software, firmware and/or combinations thereof. By way of example and not limitation, the computing device 102 may include a microcontroller or other suitable hardware logic device configured to implement various functionally that is described herein in relation to power controller 112. In addition or alternatively, the power controller 112 may be implemented by way of a processing system of the device and one or more program modules that are executable/operable via the processing system. Further description of example implementations suitable for the power controller 112 and other described modules/functionality can be found below in relation to the discussion of an example computing device depicted in FIG. 7.
The power adapter 114 may be configured to selectively operate in multiple modes and supply multiple power levels to the computing device. The level of power supplied at a particular time may be based upon input, notifications, or other suitable feedback configured and sent to the power adapter 114 by the power controller 112 to cause the power adapter 114 to supply a corresponding level of power. Further details regarding operation of the power controller 112 and the power adapter 114 to implement multi-stage power adapter techniques can be found in the following discussion.
FIG. 2 depicts an example implementation 200 of the input device 104 of FIG. 1 as showing the flexible hinge 106 in greater detail. In this example, a connection portion 202 of the input device is shown that is configured to provide a communicative and physical connection between the input device 104 and the computing device 102. In this example, the connection portion 202 has a height and cross section configured to be received in a channel in the housing of the computing device 102, although this arrangement may also be reversed without departing from the spirit and scope thereof.
The connection portion 202 is flexibly connected to a portion of the input device 104 that includes the keys through use of the flexible hinge 106. Thus, when the connection portion 202 is physically connected to the computing device the combination of the connection portion 202 and the flexible hinge 106 supports movement of the input device 104 in relation to the computing device 102 that is similar to a hinge of a book.
For example, rotational movement may be supported by the flexible hinge 106 such that the input device 104 may be placed against the display device 110 of the computing device 102 and thereby act as a cover. The input device 104 may also be rotated so as to be disposed against a back of the computing device 102, e.g., against a rear housing of the computing device 102 that is disposed opposite the display device 110 on the computing device 102.
Naturally, a variety of other orientations are also supported. For instance, the computing device 102 and input device 104 may assume an arrangement such that both are laid flat against a surface as shown in FIG. 1. In another instance, a typing arrangement may be supported in which the input device 104 is laid flat against a surface and the computing device 102 is disposed at an angle to permit viewing of the display device 110, e.g., such as through use of a kickstand disposed on a rear surface of the computing device 102. Other instances are also contemplated, such as a tripod arrangement, meeting arrangement, presentation arrangement, and so forth.
The connecting portion 202 is illustrated in this example as including magnetic coupling devices 204, 206, mechanical coupling protrusions 208, 210, and a plurality of communication contacts 212. The magnetic coupling devices 204, 206 are configured to magnetically couple to complementary magnetic coupling devices of the computing device 102 through use of one or more magnets. In this way, the input device 104 may be physically secured to the computing device 102 through use of magnetic attraction.
The connecting portion 202 also includes mechanical coupling protrusions 208, 210 to form a mechanical physical connection between the input device 104 and the computing device 102. The mechanical coupling protrusions 208, 210 are shown in greater detail in the following figure.
FIG. 3 depicts an example implementation 300 shown a perspective view of the connecting portion 202 of FIG. 2 that includes the mechanical coupling protrusions 208, 210 and the plurality of communication contacts 212. As illustrated, the mechanical coupling protrusions 208, 210 are configured to extend away from a surface of the connecting portion 202, which in this case is perpendicular although other angles are also contemplated.
The mechanical coupling protrusions 208, 210 are configured to be received within complimentary cavities within the channel of the computing device 102. When so received, the mechanical coupling protrusions 208, 210 promote a mechanical binding between the devices when forces are applied that are not aligned with an axis that is defined as correspond to the height of the protrusions and the depth of the cavity.
For example, when a force is applied that does coincide with the longitudinal axis described previously that follows the height of the protrusions and the depth of the cavities, a user overcomes the force applied by the magnets solely to separate the input device 104 from the computing device 102. However, at other angles the mechanical coupling protrusion 208, 210 are configured to mechanically bind within the cavities, thereby creating a force to resist removal of the input device 104 from the computing device 102 in addition to the magnetic force of the magnetic coupling devices 204, 206. In this way, the mechanical coupling protrusions 208, 210 may bias the removal of the input device 104 from the computing device 102 to mimic tearing a page from a book and restrict other attempts to separate the devices.
The connecting portion 202 is also illustrated as including a plurality of communication contacts 212. The plurality of communication contacts 212 is configured to contact corresponding communication contacts of the computing device 102 to form a communicative coupling between the devices. The communication contacts 212 may be configured in a variety of ways, such as through formation using a plurality of spring loaded pins that are configured to provide a consistent communication contact between the input device 104 and the computing device 102. Therefore, the communication contact may be configured to remain during minor movement or jostling of the devices. A variety of other examples are also contemplated, including placement of the pins on the computing device 102 and contacts on the input device 104. In at least some embodiments, the power adapter 114 may be configured as an input device 104 that is connectable to the computing device 102 via the connecting portion 202 and/or communication contacts 212 just described. In addition or alternatively, the power adapter 114 may employ a power supply connection/adapter interface that is dedicated for use by external power adapters and/or is provided separately from the described connecting portion 202 and/or communication contacts 212. Additional details regarding suitable power adapter connections and configurations are provided in relation to the following figures.
In particular, FIG. 4 depicts generally at 400 an example power adapter 114 in greater detail. In the depicted example, the power adapter is illustrated as including a power manager module 402 that represents functionality to manage power supplied by the adapter in various ways. For example, the power manager module 402 may be configured to manage communications with a computing device 102 and control the level of power supplied to the computing device accordingly. This may include selectively switching between at least a low power supply 404 and a high power supply 406. The power manager module 402 may be implemented as a component of the power adapter 114 in hardware, software, firmware, and/or a combination thereof. In one embodiment, functionality described in relation to the power manager module 402 is provided by way of microcontroller device or other suitable hardware/logic device integrated with the power adapter 114. A variety of other arrangements are also contemplated.
The low power supply 404 and high power supply 406 represent any suitable combination of hardware, software, circuitry, and/or logic that can be configured to provide different selected power levels to a device from a power source 116 (e.g., a wall socket, battery, or other source) to which the example power adapter 114 is connected. By way of example and not limitation, the power adapter may be configured to supply a nominal twelve volt power supply with current being varied to implement different power modes corresponding to different power levels. To enable a low power mode, the power manager module 402 may limit current to a relatively small value so that to low power supply 404 is safe when disconnected and/or when connector pins are contacted by a user or object. For example, the current in the low power mode may be limited in the range of approximately 20-30 milliamps. This power level provides enough power for operations of the power manager module 402/microcontroller device and is otherwise a relatively safe level of output if unintentional contacts and/or shorts of the power adapter occur. Then, in response to appropriate input/feedback from a host device, the power manager module 402 may remove or change the current limit to enable a high power mode for the high power supply 406 and more power intensive operations of the host device. Although two power modes/levels are shown by way of example, a power adapter may be configured to provide and switch between multiple (e.g., two or more) different modes and power levels. Thus, in some embodiments more than two modes/levels may be available.
In one approach, the low power supply 404 and high power supply 406 may be implemented by selectively changing/switching the amount of resistance applied in power supply circuitry of the power adapter. Under substantially constant voltage conditions (e.g., approximately twelve volts), switching the resistance results in a change in the amount of current supplied by the power adapter. Relatively higher resistance is employed for low power mode to limit the current to a safe level. The power manager module 402 may then operate to switch the power supply circuitry to high power mode by removing or reducing the resistance. The change in resistance may occur by isolating a portion of the circuitry, toggling switches to switch between multiple different circuits, or otherwise controlling the amount of resistance to implement multiple power modes.
As further shown in FIG. 4, the power adapter 114 may include or otherwise make use of a connector 408 that is configured to connect the power adapter to the computing device 102 via a corresponding adapter interface 410. The connection of the connector 408 and adapter interface 410 provides both a power coupling for supplying power from the adapter to the device and a communicative coupling to carry communications between the adapter and device. The connector 408 and adapter interface 410 may be configured in various ways to establish a suitable connection between the device and adapter. By way of example and not limitation, the example connector 408 of FIG. 4 is depicted as having five pins that create a connection by contact with five corresponding pins of the adapter interface 410. In this arrangement, two pins of the connection may be used for positive voltage, another two pins may be used for voltage return, and the remaining pin of the connection may establish a single pin communication line/channel used to convey communications between the adapter and device. A variety of other arrangements are also contemplated.
The power manager module 402 may be implemented in various ways to selectively switch between the low power supply 404 and high power supply 406 at the direction of the computing device 102. In general, the power manager module 402 is configured to recognize notifications or other suitable feedback communicated by a computing device that is indicative of a state of the device and/or a corresponding power level to supply to the device. In one approach, the low power supply 404 is employed by the power adapter 114 initially upon connection to the power source. This may occur both when the power adapter 114 is disconnected from the computing device 102 and when the power adapter 114 is connected to the computing device 102. Thus, a “safe” level of power may be supplied at select times including when the adapter in not connected to the appropriate adapter interface 410, when initially connected to a device, and/or when the device is otherwise not ready for full power (e.g., upon waking from a sleep/hibernate mode, loose connector, etc.). The power manager module 402 may then continue to operate the power adapter 114 using the low power supply 404 until a notification or other suitable feedback from the device is obtained that indicates the computing device 102 is ready to accept the high power supply 406.
The low power supply 404 provides power sufficient to enable the computing device 102 to at least recognize a connection to the power supply and perform some basic operations such as to charge a battery of the device, establish communication with the power adapter, initialize the device, run a microcontroller that implements functionality of the power controller 112, and so forth. In other words, the low power supply 404 provides enough power for a subset of the full device functionality. For instance, the low power supply 404 enables operation of the power controller 112 of the computing device to perform power management tasks including generating notifications/feedback for communication to the power adapter 114 at appropriate times. The power controller 112 may operate using relatively low power, independently of operating a “primary” processing system (for example, one or more central processing units of the device) of the host computing device, and/or without booting/executing an operating system or using other device components and applications. In other words, the power controller 112 may operate to perform some power management tasks without having to operate or supply power to the processing system and other device components (e.g., device memory, network interface, display device, etc.) and/or without completely starting-up or waking-up the computing device.
In particular, the power controller 112 may recognize coupling of the connector 408 to the adapter interface 410 when a user inserts or otherwise connects/attaches the adapter to the device and/or during an initial boot sequence after a shutdown, a period on inactivity, or waking up from a sleep/hibernate mode. The power controller 112 may further perform one or more checks to ensure the computing device is ready for full power, which may include testing the connection to the connector 408, ascertaining a device state for the computing device, making sure that a device battery is charged to a threshold level for device operations, identifying the adapter, verifying that voltage output and/or other characteristics of the adapter are valid, and so forth. Based on these and/or other tests, the power controller 112 determines whether or not the computing device is ready for the high power supply 406.
When the power controller 112 determines that the device is ready for switching to full power, the power controller 112 generates feedback and communicates the feedback to the power adapter 114 via the communication channel/line to cause a switch between power modes. In response to suitable feedback, the power manager module 402 may then cause a switch from the low power supply 404 to the high power supply 406. The high power supply is sufficient to enable “normal” device operations such as booting an operating system, running a primary processing system of the device, executing applications, establishing network connections, polling for messages/notifications, and so forth.
The feedback generated and communicated by the power controller 112 may be configured in various ways. Generally speaking, the power controller 112 may generate a notification or signal that is recognizable by the power adapter and in particular the power manager module 402. For instance, the power controller 112 may generate and send an alphanumeric code, a repeating signal pattern, a notification message, a binary value, or other feedback suitable to convey information regarding whether or not the computing device is ready for the high power supply 406. Alternatively, the feedback may indicate a particular selected power mode/level from multiple (e.g., two or more) available levels. When the feedback/pattern is being sent by the power controller 112, the power adapter 114 may recognize this and switch to high power mode. When the feedback/pattern is absent or concludes, the power adapter may continue to operate in low power mode or if currently operating in high power mode, switch back to the low power mode. The feedback/pattern may discontinue for example if the connector 408 is detached or if the host device is shutdown.
In one particular example, the feedback/notification is in the form of a patterned signal that is produced by the power controller 112 and communicated to the power adapter 114 via the communicative coupling established through attachment of the connector 408 to the adapter interface 410. A variety of different patterned signals are contemplated. The patterned signal is configured to use a non-random format that is expected by the power manager module 402 and generally prevents the power manager module 402 from recognizing random inputs that may be inadvertently generated. By way of example, the pulsed signal may be configured as a repeating pattern of voltage pulses that vary from zero to a peak value at a designated periodic time interval. One suitable example of a pulsed signal that may be employed by the power controller 112 produces a pattern having a peak voltage of 3.3 volts for five milliseconds that repeats every one hundred milliseconds. Naturally, various other periodic voltage patterns and other types of repeating patterns may also be employed.
Having considered the preceding discussion of an example operating environment and devices, consider now a discussion of some example procedures which includes further implementation details regarding the example devices techniques for a multi-stage power adapter.
Example Procedures
The following discussion describes multi-stage power adapter techniques that may be implemented utilizing the previously described systems and devices. Aspects of each of the procedures may be implemented in hardware, firmware, software, or a combination thereof. The procedures are shown as a set of blocks that specify operations performed by one or more devices and are not necessarily limited to the orders shown for performing the operations by the respective blocks. In portions of the following discussion, reference may be made to the example operating environment 100 of FIG. 1 and the example devices of FIGS. 2-4, respectively.
FIG. 5 depicts an example procedure 500 in which a power level supplied by an adapter is selectively switched. In at least some embodiments, the procedure may be performed by a suitably configured power adapter, such as the example power adapter 114 of FIG. 4 that includes or otherwise make use of a power manager module 402.
An initial connection of a power adapter to a power source is recognized (block 502). For example, a power manager module 402 implemented by a power adapter 114 may recognize when the power adapter 114 is connected to a power source 116, such as when a user plugs the adapter into a wall socket. The power manager module 402 may cause the power adapter 114 to initially operate in a low power mode. For example, the power manager module 402 may set power supply circuitry of the power adapter 114 to limit current by selecting relatively high resistance as described previously or by using other suitable techniques to select a low power mode.
Low power is supplied upon the initial connection to the host device (block 504). For instance, a user may attach the power adapter 114 to host device, such as by plugging the connector 408 into the adapter interface 408 of the example computing device 102 illustrated in FIG. 4. Alternatively, the power adapter 114 may already be attached to the host device when the adapter is connected to the power source 116. In either case, the power manager module 402 continues to operate the adapter in low power mode upon initial connection to the host device. The connection may establish a communicative coupling between the adapter and the host device as describe previously. When the adapter is connected, the power manager module 402 may monitor this communication connection to detect notifications or other feedback generated by the power controller 112.
In particular, a notification is detected from the host device that is configured to indicate to the power adapter that the host device is ready for high power (block 506) and high power is supplied to the host device in response to detection of the notification (block 508). Any suitable notification may be employed. For instance, a pulsed signal may be generated via the power controller 112 and communicated over a communication channel/line established between the host device and adapter as described in the preceding discussion. The power controller 112 may generate the pulsed signal in response to a determination that the host device is ready for high power. The determination may be made based in part upon various tests including at least making sure that the adapter is attached properly and/or that the adapter is capable of supplying power in an acceptable range.
The power manager module 402 may be configured to detect suitably configured notifications, such as a pulsed signal that is in an expected format. In response to detecting an appropriate notification, signal, or other feedback, the power manager module 402 may cause a switch from the low power mode to a high power mode in which high power is supplied, or otherwise switch between multiple available power modes. As mentioned, this may involve selectively operating and/or switching circuitry of the adapter to toggle between different power modes.
FIG. 6 depicts an example procedure 600 in which a device communicates a notification to cause an adapter to switch between power supply modes. In at least some embodiments, the procedure may be performed by a suitably configured computing device, such as the example computing device 102 of FIG. 4 that includes or otherwise make use of a power controller 112. A low power supply is obtained from the power adapter in a low power mode (block 602) and connection of a power adapter to an adapter interface of a host device is detected (block 604). For example, initially upon connection to a host device a power adapter may supply low power as previously discussed. A power controller 112 may be configured to detect connection of the adapter in various scenarios and perform corresponding power management operations.
For example, if the host device is operating on internal battery power, the power controller 112 may initiate operations to switch to power supplied by the adapter and/or to charge the battery if appropriate. The power controller 112 may also detect an attached adapter when waking up from a sleep mode or hibernation state. In yet another scenario, the host device may have run out of internal battery power and therefore may be completely shut down. Low power supplied by the power adapter, though, is sufficient to enable operation of the power controller 112 to start-up and perform designated power management operations, including at least controlling selection of modes for multi-stage power adapter techniques described above and below. In each of these scenarios, the multi-stage power adapter may operate in low power mode until the power adapter is notified by the host device to switch to high power mode and supply high power for normal device operations.
In particular, a determination is made regarding whether the host device is ready for a high power supply (block 606). The determination may be made by the power controller 112 based on one or more tests as described above. When the device is ready, a notification is generated for communication to the power adapter to cause the power adapter to switch to a high power supply mode (block 608) and the host device obtains high power supply from the power adapter in response to communication of the notification (block 610). In general, the power controller 112 may generate and communicate a suitable notification after ascertaining that the connection to the adapter is proper and/or that the adapter is configured to supply power output within an acceptable range that is compatible with the host device.
In some embodiments, the power controller 112 may also be configured to identify and distinguish between different adapters based on identifying data obtained from the adapter via the communicative coupling. The identifying data associates an adapter with a particular adapter type. For example, the power controller 112 may obtain and/or read a resistance value of an identification resistor included within circuitry of the power adapter. The resistance value of the identification resistor may be set to different values for different types of adapters so that the power controller 112 may identify the type of adapter that is attached. Based on this identification, the power controller 112 may recognize the capabilities of various different adapters and perform power management operations that correspond to the particular type of adapter that is currently connected. Thus, based on various different checks, the power controller 112 may determine that the host device is ready to receive high power from the adapter and signal the adapter that the host device is ready. To do so, the power controller 112 generates a suitable notification, which may be configured as a notification message, a binary value or other code, a pulsed signal, and so forth.
On the other hand, when it is determined per block 606 that the device is not ready for high power supply, the host device may continue to obtain the low power supply. In some embodiments, the absence of any notification signals the adapter to continue operating in the low power mode or switch to the low power mode. In some scenarios, though, the power controller 112 may generate different notifications or signals that are indicative of different modes and cause the power adapter to switch to a particular mode that is selected when a corresponding signal is recognized. The determination regarding whether the device is ready may then be repeated until the device is ready or the process is interrupted by some other operation, such as a timeout, shutdown of the host device, disconnection of the adapter and so forth.
Having considered the foregoing example procedures, consider now a discussion of example systems and devices that may be employed to implement aspects of multi-stage power adapter techniques in one or more embodiments.
Example System and Device
FIG. 7 illustrates an example system generally at 700 that includes an example computing device 702 that is representative of one or more computing systems and/or devices that may implement the various techniques described herein. The computing device 702 may be, for example, be configured to assume a mobile configuration through use of a housing formed and size to be grasped and carried by one or more hands of a user, illustrated examples of which include a mobile phone, mobile game and music device, and tablet computer although other examples are also contemplated.
The example computing device 702 as illustrated includes a processing system 704, one or more computer-readable media 706, and one or more I/O interface 708 that are communicatively coupled, one to another. Although not shown, the computing device 702 may further include a system bus or other data and command transfer system that couples the various components, one to another. A system bus can include any one or combination of different bus structures, such as a memory bus or memory controller, a peripheral bus, a universal serial bus, and/or a processor or local bus that utilizes any of a variety of bus architectures. A variety of other examples are also contemplated, such as control and data lines.
The processing system 704 is representative of functionality to perform one or more operations using hardware. Accordingly, the processing system 704 is illustrated as including hardware element 710 that may be configured as processors, functional blocks, and so forth. This may include implementation in hardware as an application specific integrated circuit or other logic device formed using one or more semiconductors. The hardware elements 710 are not limited by the materials from which they are formed or the processing mechanisms employed therein. For example, processors may be comprised of semiconductor(s) and/or transistors (e.g., electronic integrated circuits (ICs)). In such a context, processor-executable instructions may be electronically-executable instructions.
The computer-readable storage media 706 is illustrated as including memory/storage 712. The memory/storage 712 represents memory/storage capacity associated with one or more computer-readable media. The memory/storage component 712 may include volatile media (such as random access memory (RAM)) and/or nonvolatile media (such as read only memory (ROM), Flash memory, optical disks, magnetic disks, and so forth). The memory/storage component 712 may include fixed media (e.g., RAM, ROM, a fixed hard drive, and so on) as well as removable media (e.g., Flash memory, a removable hard drive, an optical disc, and so forth). The computer-readable media 706 may be configured in a variety of other ways as further described below.
Input/output interface(s) 708 are representative of functionality to allow a user to enter commands and information to computing device 702, and also allow information to be presented to the user and/or other components or devices using various input/output devices. Examples of input devices include a keyboard, a cursor control device (e.g., a mouse), a microphone, a scanner, touch functionality (e.g., capacitive or other sensors that are configured to detect physical touch), a camera (e.g., which may employ visible or non-visible wavelengths such as infrared frequencies to recognize movement as gestures that do not involve touch), and so forth. Examples of output devices include a display device (e.g., a monitor or projector), speakers, a printer, a network card, tactile-response device, and so forth. Thus, the computing device 702 may be configured in a variety of ways to support user interaction.
The computing device 702 is further illustrated as being communicatively and physically coupled to an input device 714 that is physically and communicatively removable from the computing device 702. In this way, a variety of different input devices may be coupled to the computing device 702 having a wide variety of configurations to support a wide variety of functionality. In this example, the input device 714 includes one or more keys 716, which may be configured as press-sensitive keys, mechanically switched keys, and so forth.
The input device 714 is further illustrated as include one or more modules 718 that may be configured to support a variety of functionality. The one or more modules 718, for instance, may be configured to process analog and/or digital signals received from the keys 716 to determine whether a keystroke was intended, determine whether an input is indicative of resting pressure, support authentication of the input device 714 for operation with the computing device 702, and so on.
Various techniques may be described herein in the general context of software, hardware elements, or program modules. Generally, such modules include routines, programs, objects, elements, components, data structures, and so forth that perform particular tasks or implement particular abstract data types. The terms “module,” “functionality,” and “component” as used herein generally represent software, firmware, hardware, or a combination thereof. The features of the techniques described herein are platform-independent, meaning that the techniques may be implemented on a variety of commercial computing platforms having a variety of processors.
An implementation of the described modules and techniques may be stored on or transmitted across some form of computer-readable media. The computer-readable media may include a variety of media that may be accessed by the computing device 702. By way of example, and not limitation, computer-readable media may include “computer-readable storage media” and “computer-readable signal media.”
“Computer-readable storage media” may refer to media and/or devices that enable persistent and/or non-transitory storage of information in contrast to mere signal transmission, carrier waves, or signals per se. Thus, computer-readable storage media refers to non-signal bearing media. The computer-readable storage media includes hardware such as volatile and non-volatile, removable and non-removable media and/or storage devices implemented in a method or technology suitable for storage of information such as computer readable instructions, data structures, program modules, logic elements/circuits, or other data. Examples of computer-readable storage media may include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, hard disks, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or other storage device, tangible media, or article of manufacture suitable to store the desired information and which may be accessed by a computer.
“Computer-readable signal media” may refer to a signal-bearing medium that is configured to transmit instructions to the hardware of the computing device 702, such as via a network. Signal media typically may embody computer readable instructions, data structures, program modules, or other data in a modulated data signal, such as carrier waves, data signals, or other transport mechanism. Signal media also include any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media include wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared, and other wireless media.
As previously described, hardware elements 710 and computer-readable media 706 are representative of modules, programmable device logic and/or fixed device logic implemented in a hardware form that may be employed in some embodiments to implement at least some aspects of the techniques described herein, such as to perform one or more instructions. Hardware may include components of an integrated circuit or on-chip system, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a complex programmable logic device (CPLD), and other implementations in silicon or other hardware. In this context, hardware may operate as a processing device that performs program tasks defined by instructions and/or logic embodied by the hardware as well as a hardware utilized to store instructions for execution, e.g., the computer-readable storage media described previously.
Combinations of the foregoing may also be employed to implement various techniques described herein. Accordingly, software, hardware, or executable modules may be implemented as one or more instructions and/or logic embodied on some form of computer-readable storage media and/or by one or more hardware elements 710. The computing device 702 may be configured to implement particular instructions and/or functions corresponding to the software and/or hardware modules. Accordingly, implementation of a module that is executable by the computing device 702 as software may be achieved at least partially in hardware, e.g., through use of computer-readable storage media and/or hardware elements 710 of the processing system 704. The instructions and/or functions may be executable/operable by one or more articles of manufacture (for example, one or more computing devices 702 and/or processing systems 704) to implement techniques, modules, and examples described herein.
CONCLUSION
Although the example implementations have been described in language specific to structural features and/or methodological acts, it is to be understood that the implementations defined in the appended claims is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as example forms of implementing the claimed features.

## Claims

1. A power adapter external to a host computing device comprising:
a supply circuit configured to supply at least a first power level and a second power level, the first power level supplied to the host computing device to power a microcontroller of the host computing device for performance of power management tasks without using a primary processing system integrated into the host computing device, the supply circuit operable to provide different power levels under substantially constant voltage by changing an amount of resistance applied in the supply circuit and thereby vary an amount of current supplied; and
a power manager implemented by a microcontroller integrated with the power adapter configured to detect a notification from the host computing device, the notification indicating to the power manager that the host computing device is ready for the second power level to be supplied by the power adapter, and initiate a switch of the supply circuit to the second power level in response to the notification, the second power level supplied to at least the primary processing system of the host computing device.

2. A power adapter as described in claim 1, wherein the notification is a patterned signal generated by a power controller of the host computing device.

3. A power adapter as described in claim 2, wherein the patterned signal comprises a repeating pattern of voltage pulses.

4. A power adapter as described in claim 1, wherein supplying the second power level comprises causing the power adapter to switch from a first power mode to a second power mode by decreasing an amount of resistance applied in the supply circuitry of the power adapter.

5. A power adapter as described in claim 4, wherein the power adapter is configured to implement multiple power modes including the first power mode and the second power mode.

6. A power adapter as described in claim 1, wherein the first power level supplied by the power adapter is sufficient to operate the microcontroller of the host computing device to generate and communicate notifications to cause a switch to a different power level responsive to a determination that the host computing device is ready for the different power level.

7. A power adapter as described in claim 1, the power manager module further configured to recognize an initial connection of the power adapter to a power source and cause the power adapter to supply the first power level until the notification from the host computing device is detected.

8. A power adapter as described in claim 1, wherein:
the power adapter incorporates a five pin connector connectable to an adapter interface of the host computing device; and
one of the five pins is configured to form a communicative coupling to the host computing device when connected to the adapter interface that is employed to convey the notification from the host computing device to the power adapter.

9. A host computing device comprising:
one or more processors, the one or more processors including a power controller configured to operate independently of a primary processing system integrated into the host computing device;
one or more computer-readable storage media having stored thereon instructions that, when executed by the one or more processors, cause the processors to:
obtain a first power level of two or more power levels from a power adapter external to the host computing device upon connection to the power adapter, the first power level supplied to the host computing device sufficient to operate the power controller of the host computing device to perform power management tasks without supplying power to the primary processing system of the host computing device, the power adapter configured to provide the two or more power levels under substantially constant voltage by changing an amount of resistance applied in a supply circuit and thereby vary an amount of current supplied to the host device;
determine whether the host computing device is ready for a second power level from the power adapter based at least in part on data obtained from the power adapter; and
responsive to determining that the host computing device is ready for the second power level from the power adapter:
generate a notification for communication to the power adapter for recognition and handling by a power manager module implemented by a microcontroller integrated with the power adapter to cause the power adapter to supply the second power level to at least the primary processing system of the host computing device.

10. A computing device as described in claim 9, wherein the notification comprises an alphanumeric code.

11. A computing device as described in claim 9, wherein the notification comprises a non-random signal pattern.

12. A computing device as described in claim 9, the instructions further causing the processors to communicate the notification to the power adapter via a single pin communication channel established by the connection of the power adapter to the adapter interface.

13. A computing device as described in claim 9, wherein to determine whether the host computing device is ready for the second power level from the power adapter includes ascertaining whether a connector of the power adapter is attached properly to the adapter interface of the host computing device.

14. A computing device as described in claim 9, wherein to determine whether the host computing device is ready for the second power level from the power adapter includes verifying whether power output supplied by the power adapter is compatible with the host computing device.

15. A computing device as described in claim 9, wherein to determine whether the host computing device is ready for the second power level from the power adapter comprises obtaining identifying data from the power adapter to identify a type of adapter associated with the power adapter.

16. The computing device as described in claim 9, the power controller further configured to determine whether the host device is ready for the second power level based on whether the host device is operating on internal battery power, the host device is waking up from sleep mode or hibernation mode, or the host device has run out of battery power.

17. A power adapter for a host computing device comprising:
a connector configured to connect the power adapter to the host computing device, the power adapter being external to the host computing device and connectable to an external power source to supply power to the host computing device;
a power supply circuit implemented in the power adapter configured to provide two or more power levels under substantially constant voltage by changing an amount of resistance applied in the power supply circuit and thereby vary an amount of current supplied to the host computing device, the two or more power levels including at least a first power level and a second power level, the first power level sufficient to operate a power controller of the host computing device to perform power management tasks and insufficient to power other components of the host computing device; and
a power manager implemented by a microcontroller integrated with the power adapter operable to selectively switch between the first power level and the second power level based upon feedback obtained from the host device configured to indicate to the power adapter that the host computing device is ready for the second power level, the feedback communicated by the power controller of the host computing device for recognition and handling by the power manager implemented by the microcontroller of the power adapter, the second power level supplied to at least a primary processing system of the host computing device.

18. A power adapter as described in claim 17, wherein the power manager is configured to cause the amount of resistance applied in the power supply circuit to change by toggling switches to isolate a portion of the circuit or switch between multiple different circuit paths.

19. A power adapter as described in claim 17, wherein the feedback comprises a pulsed voltage signal that is received by the power manager from a power controller of the host computing device, the pulsed voltage signal being communicated by the power controller responsive to a determination that the host computing device is ready for the second power level and configured to cause the power manager module to switch to the second power level.