Abstract:
In some examples, a power adapter includes a voltage regulator, first and second resistors, a switch to alternately connect the first and second resistors to a signal node coupled to a load circuit external of the power adapter, and a voltage controller to control the switch to set a first mode of operation, and responsive to the switch setting the first mode of operation, determine a power requirement of the load circuit, and control the voltage regulator to provide a supply voltage to a power node in accordance with the power requirement of the load circuit, and control the switch to set the second mode of operation that causes the load circuit to determine a power rating of the power adapter and to operate a load of the load circuit according to the power rating of the power adapter.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a continuation of U.S. application Ser. No. 14/766,824, having a national entry date of Aug. 10, 2015, which is a national stage application under 35 U.S.C. §371 of PCT/US2013/029255, filed Mar. 6, 2013, which are both hereby incorporated by reference in their entirety. 
     
    
     BACKGROUND 
       [0002]    Electrical power adapters are used to convert alternating-current into regulated direct-current for use with laptop computers, cellular telephones and other load devices. A load device draws current provided by the adapter. The present teachings address the foregoing concerns. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]    The present embodiments will now be described, by way of example, with reference to the accompanying drawings, in which: 
           [0004]      FIG. 1  depicts a diagrammatic view of a system according to one example; 
           [0005]      FIG. 2  depicts a schematic diagram of circuitry according to one example; 
           [0006]      FIG. 3  is a flow diagram depicting a method according to one example; 
           [0007]      FIG. 4  depicts a table of illustrative resistor values according to one example; 
           [0008]      FIG. 5  depicts a table of illustrative resistor values according to another example; and 
           [0009]      FIG. 6  depicts a schematic diagram of circuitry according to another example. 
       
    
    
     DETAILED DESCRIPTION 
     Introduction 
       [0010]    Examples of electronic circuits and corresponding methods are provided. A power adapter is coupled to load device such that a power node and a signal node and a ground node are common to both entities. A regulated supply voltage is provided by the power adapter to the load device in accordance with a voltage sensed at the signal node. Electrical current drawn by the load device is limited in accordance with a voltage sensed at the signal node. 
         [0011]    In one embodiment, an electronic circuit includes a power circuit having one or more resistors either directly or selectively coupled to a signal node. The power circuit also includes a voltage controller to detect a voltage at the signal node and to provide a corresponding voltage control signal. The power circuit includes a voltage regulator to provide a supply voltage to a power node in accordance with the voltage control signal. The electronic circuit also includes a load circuit to be removably coupled to the signal node and the power node. The load circuit includes a programming resistor coupled between the signal node and a ground node. The load circuit also includes a load controller to sense a voltage at the signal node and to provide a corresponding load control signal. 
         [0012]    In another embodiment, a system includes a computer including a load controller. The system also includes a power adapter having a power node and a signal node and a ground node each to be disconnectably coupled to the computer. The power adapter is configured to detect a voltage at the signal node and to provide a corresponding supply voltage at the power node. The load controller is configured to detect a voltage at the signal node and to provide a load control signal. The load control signal causes the computer to limit current drawn from the power adapter. 
         [0013]    In yet another embodiment, a method includes coupling one or more resistors within an adapter, one at a time, into series relationship with a programming resistor within a load entity. The method also includes sensing one or more voltages at a signal node common to the adapter and the load entity. The method further includes providing a regulated source voltage from the adapter to the load entity in accordance with at least one of the sensed voltages. The method also includes limiting electrical current drawn by the load entity in accordance with at least one of the sensed voltages. 
       First Illustrative System 
       [0014]    Reference is now directed to  FIG. 1 , which depicts a diagrammatic view of a system  100 . The system  100  is illustrative and non-limiting with respect to the present teachings. Thus, other systems can be configured and/or operated in accordance with the present teachings. 
         [0015]    The system  100  includes a laptop computer (laptop)  102 . The laptop  102  can be defined by any such device that includes electronic circuitry according to the present teachings. The laptop  102  receives voltage-regulated, direct-current (DC) power from an electrical adapter (power adapter, or power circuit)  104  by way of a connecting cable  106 . In turn, the electrical adapter  104  is connected to a source  108  of alternating-current (AC) power. The electrical adapter  104  includes circuitry according to the present teachings. 
         [0016]    Illustrative operation of the system  100  is as follows: the electrical adapter  104  receives AC power from the source  108 . The electrical adapter  104  assumes a first mode during which a first voltage signal is detected by the electrical adapter  104  and correlated to a voltage requirement of the laptop (i.e., load device)  102 . The electrical adapter  104  then provides regulated DC power of the corresponding voltage to the laptop  102  by way of the connecting cable  106 . 
         [0017]    The electrical adapter  104  assumes a second mode during which a second voltage signal is detected by circuitry of the laptop  102  and correlated to operate according to a maximum power (or electrical current) capacity for the electrical adapter  104 . The power rating can optionally be a continuous operating maximum or a temporary (e.g., ten seconds, etc.) operating maximum. The determined power rating is then used by the laptop  102  in regulating its own operations (i.e., current draw) to within the power output capability or limit of the electrical adapter  104 . 
       First Illustrative Embodiment 
       [0018]      FIG. 2  is a schematic diagram depicting circuitry  200  according to an embodiment of the present teachings. The circuitry  200  is illustrative and non-limiting in nature. Other circuitry consistent with the present teachings is also contemplated. The circuitry  200  includes a portion  200 A that is provided (i.e., supported or housed) within an electrical adapter (ADAPTER), and a portion  200 B that is provided within a laptop computer (COMPUTER). Thus, the circuitry  200  is as depicted when an electrical adapter (e.g.,  104 ) is (removably) coupled to a laptop computer (e.g.,  102 ) or other load device in accordance with the present teachings. 
         [0019]    The circuitry portions  200 A and  200 B are referred to as “compatible” with each other by virtue of their cooperative configurations. Thus, the electrical adapter portion  200 A is compatible with the laptop computer (or load) portion  200 B, and vice versa. 
         [0020]    The circuitry  200  includes a power node  202 , a signal node  204  and ground node  206 . During normal operation, a regulated direct-current voltage is provided between the nodes  202  and  206 . The adapter portion  200 A includes a voltage regulator  208  to provide a selectable (adjustable), regulated supply voltage between the power node  202  and the ground node  206 . The voltage regulator  208  is controllably adjusted by way of voltage control signal described hereinafter. The voltage regulator  208  can be defined, at least in part, by a switching-type regulator, a linear-type regulator, or other suitable voltage control circuitry. The voltage regulator  208  is configured to be coupled to a source of electrical energy such as a line-level utility supply (e.g., one-hundred twenty volts AC). 
         [0021]    The adapter portion  200 A also includes a resistor  210  coupled (or connected) to the power node  202 . The resistor  210  is also referred to as a biasing resistor  210  for purposes herein. The biasing resistor  210  can be selectively coupled to the signal node  204  by way of a switch  212 . In one example, the biasing resistor  210  is characterized by an electrical resistance of 10.0K Ohms. Other suitable resistance values can also be used. 
         [0022]    The adapter portion  200 A also includes a resistor  214  coupled (or connected) to the power node  202 . The resistor  214  is also referred to as a power capacity resistor  214  or power resistor  214  for purposes herein. The power capacity resistor  214  can be selectively coupled to the signal node  204  by way of the switch  212 . The power capacity resistor  214  is characterized by an electrical resistance value that corresponds to a power provisioning capacity or current supplying capacity of the adapter portion  200 A. Illustrative resistance values and corresponding electrical adapter (e.g.,  104 ) capacities are described hereinafter. 
         [0023]    The adapter portion  200 A further includes a voltage controller  216 . The voltage controller  216  is configured to detect (monitor, or sense) a voltage signal present at the signal node  204  and to correlate that signal with a voltage requirement of the laptop computer  200 B. The voltage controller  216  is also configured to provide a voltage control signal to the voltage regulator  208  causing it to provide a supply voltage at the node  202  corresponding (equal, or about equal) to the voltage requirement of the laptop computer  200 B. Furthermore, the voltage controller  216  is configured to selectively control the switch  212  so as to selectively couple either the biasing resistor  210  (i.e., first mode) or the power capacity resistor  214  (i.e., second mode) to the signal node  204 . 
         [0024]    The voltage controller  216  can be defined by or include any suitable electronic constituency. Without limitation, the voltage controller  216  can be at least partially defined by an application specific integrated circuit (ASIC), a microcontroller, a microprocessor, analog or digital or hybrid circuitry, and so on. Other elements or configurations can also be used. 
         [0025]    The computer portion  200 B of the circuitry  200  includes a resistor  218  that is connected between the signal node  204  and the ground node  206 . The resistor  218  is also referred to as a programming resistor  218  for purposes herein. The programming resistor  218  is characterized by an electrical resistance value that corresponds to a voltage requirement of the computer portion (i.e., load entity or device)  2006 . 
         [0026]    The computer portion  200 B also includes a load controller  220 . The load controller  220  is configured to detect a voltage signal present at the signal node  204  and to correlate that signal with a power (or current) provisioning capacity of the adapter portion  200 A. The load controller  220  is also configured to provide a load control signal causing a load device (entity, or circuitry)  222  to limit its power consumption (i.e., current draw) from the adapter portion  200 A in accordance with the adapter capacity. The load controller  220  is configured such that the power capacity signal is detected when the power capacity resistor  214  is coupled to the signal node  204 . (i.e., during the second mode). 
         [0027]    The load controller  220  can be defined by or include any suitable electronic constituency. Without limitation, the load controller  220  can be at least partially defined by an application specific integrated circuit (ASIC), a microcontroller, a microprocessor, analog or digital or hybrid circuitry, and so on. Other elements or configurations can also be used. 
         [0028]    The computer portion  200 B further includes the load device  222  introduced above. The load device  222  is coupled to receive operating power from the power node  202  and the ground node  206 . The load device  222  can be variously defined and can include a motherboard of a laptop computer, a peripheral or peripherals of a computer, an electronic display, data acquisition circuitry, control instrumentation, and so on. Other load devices  222  can also be defined and used. The load device  222  is configured to perform various operations in accordance with its respective normal functions. The load device  222  is also configured to control (throttle, or modulate) its operations, or intensities of those operations, in accordance with the load control signal from the load controller  220 . Electrical current draw (power consumption) by the load device  222  is thus limited or constrained within the power provisioning capacity of the adapter portion  200 A. 
         [0029]    The circuitry  200  includes resistors  210 ,  214  and  218  as described above, the respective resistive values of which serve to establish (communicate, or program) required voltage and power capacity parameters for normal operations of the adapter portion  200 A and the computer portion  200 B, respectively. However, the present teachings also contemplate that respective elements characterized by electrical impedance (i.e., resistance and/or reactance) can also be used to establish operating parameters for the adapter portion  200 A and the computer portion  200 B. Thus, inductors, capacitors or other elements—as well as resistors—can also be used in functions analogous those of resistors  210 ,  214  and/or  218 . 
       First Illustrative Method 
       [0030]      FIG. 3  is a flow diagram depicting a method according to one embodiment of the present teachings. The method of  FIG. 3  includes particular operations and order of execution. However, other methods including other operations, omitting one or more of the depicted operations, and/or proceeding in other orders of execution can also be used according to the present teachings. Thus, the method of  FIG. 3  is illustrative and non-limiting in nature. Reference is also made to  FIGS. 1-2  in the interest of understanding the method of  FIG. 3 . 
         [0031]    At  300 , an electrical adapter is connected to a load device. For purposes of illustrative and non-limiting example, it is assumed that the adapter  104  is connected to the laptop  102  by way of the cable  106 . In another scenario, the load device can be a cellular telephone, video gaming console, etc. The power node  202 , the signal node  204  and the ground node  206 , respectively, are now electrically common to both the adapter  104  and the laptop  102 . 
         [0032]    At  302 , the electrical adapter is connected to a source of electrical energy. For purposes of the ongoing example, the electrical adapter  104  is connected (i.e., plugged in) to the electrical source  108 . The electrical adapter  104  is now coupled to provide regulated direct-current energy to the laptop  102  once electrical parameters have been communicated there between. 
         [0033]    At  304 , a biasing resistor is switched into series relationship with a programming resistor. For purposes of the example, the voltage controller  216  causes the switch  212  to couple the biasing resistor  210  to the signal node  204  and into series-circuit relationship with the programming resistor  218 . A voltage divider is thus defined. The adapter  104  and the laptop computer  102  are operating in a “first mode” with respect to communicating with each other. 
         [0034]    At  306 , a voltage at the signal node is sampled. For purposes of the present example, a voltage across the programming resistor  218 , which is present at the signal node  204 , is sampled by the voltage controller  216 . The voltage controller  216  digitally quantifies this voltage signal. The switch (or relay)  212  is in a “first mode” state during this step. 
         [0035]    At  308 , the sensed voltage is correlated to a voltage requirement of the load device. For purposes of the present example, the voltage controller  216  evaluates the digital quantification of the signal sampled at step  306  and determines that an operating voltage of nineteen volts (i.e., 19.0 Volts) is required by the laptop  102 . The voltage controller  216  can make such determination by way of a lookup table, a predetermined mathematical function, or by another suitable technique. 
         [0036]    At  310 , a power capacity resistor is switched into series relationship with the programming resistor. For purposes of the present example, the voltage controller  216  causes the switch  212  to couple the power capacity resistor  214  to the signal node  204  and into series-circuit relationship with the programming resistor  218 , defining a voltage divider. The adapter  104  and the laptop computer  102  are thus operating in a “second mode” with respect to communicating with each other. 
         [0037]    At  312 , a voltage at the signal node is sampled. For purposes of the present example, a voltage present at the signal node  204  is sampled by the load controller  220  and is digitally quantified. The switch (or relay)  212  is maintained in a “second mode” state during this step. 
         [0038]    At  314 , the sensed voltage is correlated to a power capacity of the electrical adapter. For purposes of the present example, the load controller  220  evaluates the digital quantification of the signal sampled at step  312  and determines that the adapter  104  can provide ninety watts (i.e., 90.0 Watts) of power. The load controller  220  can make such determination by way of a lookup table, a predetermined mathematical function, or by another suitable technique. 
         [0039]    At  316 , the adapter is operated to provide the voltage required by the load device. For purposes of the present example, the voltage controller  216  provides a voltage control signal to the voltage regulator  208 , causing it to provide a regulated nineteen volts DC between the power node  202  and the ground node  206 . 
         [0040]    At  318 , the load device is operated in accordance with the power capacity of the adapter. For purposes of the present example, the load controller  220  provides a load control signal to the load device  222  causing it to throttle or limit normal operations so as to consume ninety watts (or less) from the adapter  104 . Such wattage limitations can also be considered (or implemented) in terms of limiting instantaneous current draw (e.g., 90.0 Watts/19.0 Volts=4.73 Amps (approx.) current limit). 
         [0041]    The foregoing method is illustrative of any number of devices and methods contemplated by the present teachings. In general, and without limitation, an electrical adapter is connected to a computer or other load, and to a source of electricity. Circuitry within the electrical adapter and the load device now share a number of electrical nodes in common. A switching element couples a biasing resistor of the adapter into series with a programming resistor of the load device. A voltage present on a signal node is digitally quantified and correlated to a voltage requirement of the load device. 
         [0042]    The switching element then couples a power capacity resistor into series with the programming resistor and a voltage present on the signal node is digitally quantified and correlated to a power provisioning capacity of the electrical adapter. The electrical adapter provides regulated electrical voltage consistent with the requirements of the load device. In turn, the load device limits or throttles its respective normal operations in accordance with the power capacity of the electrical adapter. 
       Illustrative Programming Resistor Values 
       [0043]    Reference is made now to  FIG. 4 , which depicts a table  400  including illustrative and non-limiting examples of programming resistor values correlated to respective voltage requirements of a load device (e.g.,  102 ). For example, a programming resistor (e.g.,  218 ) having a value of 4.7K Ohms is correlated to a voltage requirement of 5.0 volts. In another example, a programming resistor having a value of 33K Ohms is correlated to a voltage requirement of 15.0 volts. Other resistance values correlated to other respective voltages can also be used. 
       Illustrative Power Capacity Resistor Values 
       [0044]    Attention is turned now to  FIG. 5 , which depicts a table  500  including illustrative and non-limiting examples of power capacity resistor values correlated to respective power provisioning capacities of an electrical adapter (e.g.,  104 ). For example, a power capacity resistor (e.g.,  214 ) having a value of 10K Ohms is correlated to a power capacity of 15.0 Watts. In another example, a power capacity resistor having a value of 47K Ohms is correlated to a power capacity of 70.0 Watts, and so on. Other resistance values correlated to other respective power (or current) capacities can also be used. 
       Second Illustrative Embodiment 
       [0045]      FIG. 6  is a schematic diagram depicting circuitry  600  according to another embodiment of the present teachings. The circuitry  600  is illustrative and non-limiting in nature. Other circuitry consistent with the present teachings is also contemplated. The circuitry  600  includes a portion  600 A that is provided (i.e., supported or housed) within an electrical adapter (ADAPTER), and a portion  600 B that is provided within a laptop computer (COMPUTER). Thus, the circuitry  600  is as depicted when an electrical adapter (e.g.,  104 ) is (removably) coupled to a laptop computer (e.g.,  102 ) or other load device in accordance with the present teachings. 
         [0046]    The circuitry portions  600 A and  600 B are referred to as “compatible” with each other by virtue of their cooperative configurations. Thus, the electrical adapter portion  600 A is compatible with the laptop computer (or load) portion  600 B, and vice versa. 
         [0047]    The circuitry  600  includes a power node  602 , a signal node  604  and ground node  606 . During normal operation, a regulated direct-current voltage is provided between the nodes  602  and  606 . The adapter portion  600 A includes a voltage regulator  608  to provide a selectable (adjustable), regulated supply voltage between the power node  602  and the ground node  606 . The voltage regulator  608  is controllably adjusted by way of voltage control signal described hereinafter. The voltage regulator  608  can be defined, at least in part, by a switching-type regulator, a linear-type regulator, or other suitable voltage control circuitry. The voltage regulator  608  is configured to be coupled to a source of electrical energy such as a line-level utility supply (e.g., one-hundred twenty volts AC). 
         [0048]    The adapter portion  600 A also includes a resistor  610  coupled (or connected) to the power node  602 . The resistor  610  is also referred to as a power capacity resistor  610  for purposes herein. The power capacity resistor  610  is coupled (or connected) to the signal node  604 . The power capacity resistor  610  is characterized by an electrical resistance value that corresponds to a power provisioning capacity or current supplying capacity of the adapter portion  600 A. Various suitable resistance values can also be used for the power capacity resistor  610  such as, without limitation, those described above in regard to Table  500 . 
         [0049]    The adapter portion  600 A further includes a voltage controller  612 . The voltage controller  612  is configured to detect (monitor, or sense) a voltage signal present at the signal node  604  and to correlate that signal with a voltage requirement of the laptop computer  600 B. The voltage controller  612  is also configured to provide a voltage control signal to the voltage regulator  608  causing it to provide a supply voltage at the node  602  corresponding (equal, or about equal) to the voltage requirement of the laptop computer  600 B. 
         [0050]    The voltage controller  612  can be defined by or include any suitable electronic constituency. Without limitation, the voltage controller  612  can be at least partially defined by an application specific integrated circuit (ASIC), a microcontroller, a microprocessor, analog or digital or hybrid circuitry, and so on. Other elements or configurations can also be used. 
         [0051]    The computer portion  600 B of the circuitry  600  includes a resistor  614  that is connected between the signal node  604  and the ground node  606 . The resistor  614  is also referred to as a programming resistor  614  for purposes herein. The programming resistor  614  is characterized by an electrical resistance value that corresponds to a voltage requirement of the computer portion (i.e., load entity or device)  600 B. Various suitable resistance values can also be used for the programming resistor  614  such as, without limitation, those described above in regard to Table  400 . 
         [0052]    The computer portion  600 B also includes a load controller  616 . The load controller  616  is configured to detect a voltage signal present at the signal node  604  and to correlate that signal with a power (or current) provisioning capacity of the adapter portion  600 A. The load controller  616  is also configured to provide a load control signal causing a load device  618  to limit its power consumption (i.e., current draw) from the adapter portion  600 A in accordance with the adapter capacity. The load controller  616  is configured such that the power capacity signal is detected when the power capacity resistor  610  is coupled to the signal node  604 . Optionally, the load controller  616  is also coupled to monitor a voltage present at the power node  602  and to modulate the load control signal accordingly. 
         [0053]    The load controller  616  can be defined by or include any suitable electronic constituency. Without limitation, the load controller  616  can be at least partially defined by an application specific integrated circuit (ASIC), a microcontroller, a microprocessor, analog or digital or hybrid circuitry, and so on. Other elements or configurations can also be used. 
         [0054]    The computer portion  600 B further includes the load device  618  introduced above. The load device  618  is coupled to receive operating power from the power node  602  and the ground node  606 . The load device  618  can be variously defined and can include a motherboard of a laptop computer, a peripheral or peripherals of a computer, an electronic display, data acquisition circuitry, control instrumentation, and so on. Other load devices  618  can also be defined and used. The load device  618  is configured to perform various operations in accordance with its respective normal functions. The load device  618  is also configured to control (throttle, or modulate) its operations, or intensities of those operations, in accordance with the load control signal from the load controller  618 . Electrical current draw (power consumption) by the load device  618  is thus limited or constrained in accordance with the power provisioning capacity of the adapter portion  600 A. 
         [0055]    In general, the foregoing description is intended to be illustrative and not restrictive. Many embodiments and applications other than the examples provided would be apparent to those of skill in the art upon reading the above description. The scope of the invention should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. It is anticipated and intended that future developments will occur in the arts discussed herein, and that the disclosed systems and methods will be incorporated into such future embodiments. In sum, it should be understood that the invention is capable of modification and variation and is limited only by the following claims.