Patent Publication Number: US-11658566-B2

Title: Power supply device, power supply system and method for controlling the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 14/273,444 filed on May 8, 2014, which claims the benefit of Korean Patent Application No. 10-2013-0131602 filed on Oct. 31, 2013, with the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     The present disclosure relates to a power supply system including a general-purpose power supply device. 
     Recently, portable electronic devices have tended to be operated systemically and wirelessly, to provide multimedia services, and to be digitalized, “smart” and relatively complex. In particular, multimedia services are increasingly attracting popular interest, and accordingly, multimedia services provided by small, portable devices have come to prominence. 
     Among portable electronic devices, as mobile devices such as smartphones and tablet personal computers (PCs) are prominent as information technology devices, new technology requirements for driving power supplying devices such as adapters for charging batteries in such mobile devices have also been increased. 
     Previously, only the standby power of driving power supply devices has been specified. However, as many features, including touchscreens, have been added to mobile devices, it has become necessary to reduce the influence of such device elements on mobile devices while driving power supply devices are charging such mobile devices. 
     As mobile devices are diversified in terms of the available types thereof, it is necessary to supply power to different mobile devices having different power specifications using a single power supply device. Accordingly, research into a power supply devices applicable to different mobile devices ongoing. 
     That is, different mobile devices have different rated voltages, and thus require dedicated power supply devices. For this reason, not to mention the cost burden, users have to carry as many power supply devices as they do mobile devices. 
     As a solution to solve such problems, setting a common input voltage for mobile devices at, 5 V, for example, may be contemplated. In such a solution, however, a laptop computer, for example, may require a high level of input power and thus consume a large amount of current, such that a separate heat dissipation device may be required to dissipate heat generated in the device. 
     In such a case, the volume of the power supply device is inevitably increased along with manufacturing costs thereof. 
     In the case that output voltage from the power supply device is set to be 12 V, even though the current may be decreased, it may force devices (such as smartphones) that have low input voltage and employ small and cheap elements to employ elements having higher withstand voltage levels to handle the increased input voltage. This results in an increase in manufacturing costs, as elements having higher withstand voltages are generally more expensive than elements having lower withstand voltages. Therefore, it may be difficult to use a power supply device that supplies power having a single voltage level to various devices. 
     Patent Documents 1 and 2 listed below relate to a unified power supply device. However, such a unified power supply device includes power supply circuits for supplying various levels of voltage, so that the volume of the device is increased and thus manufacturing costs are increased. 
     Therefore, in order to overcome the above problems, a novel power supply device is required that can be used for various devices. 
     RELATED ART DOCUMENT 
     
         
         (Patent Document 1) Korean Patent Laid-Open Publication No. 2009-0031085 
         (Patent Document 2) Korean Patent Laid-Open Publication No. 2007-0006969 
       
    
     SUMMARY 
     An aspect of the present disclosure may provide a general-purpose power supply system that can be used for a variety of devices requiring driving power having different voltage and current levels. 
     According to an aspect of the present disclosure, a power supply system may include: a target device and an adapter, the target device including an adapter connection switch that receives adapter recognition information to form a connection with the adapter, a voltage detection unit that receives an output voltage from the adapter, and a voltage-change-requesting unit that outputs a signal to request a voltage change based on information on the output voltage from the adapter; and the adapter including a device information recognition unit that receives the signal to request a voltage change, and an output-voltage-changing unit that changes the output voltage based on the signal to request a voltage change. 
     The voltage-change-requesting unit in the target device may be connected to the device information recognition unit in the adapter via a USB data cable. 
     The adapter may further include an adapter information output unit that outputs adapter information to the target device. 
     The target device may further include a control unit operably connected to the adapter connection switch, the voltage detection unit and the change-requesting unit. 
     The adapter may further include a control unit operably connected to the device information recognition unit and the output-voltage-changing unit. 
     The device information recognition unit may include voltage-dividing resistors to detect a level of a voltage in the USB data cable. 
     According to another aspect of the present disclosure, a power supply system may include a target device and an adapter, the target device including an adapter connection switch that receives adapter recognition information to form a connection with the adapter, a voltage detection unit that receives an output voltage from an adapter, and a voltage-change-requesting unit that outputs a voltage to request a voltage change based on information on the output voltage from the adapter; and the adapter including a device information recognition unit that receives the voltage to request a voltage change, and an output-voltage-changing unit that changes the output voltage based on the voltage to request a voltage change. 
     The voltage-change-requesting unit in the target device may be connected to the device information recognition unit in the adapter via a USB data cable, and the device information recognition unit may include voltage-dividing resistors to detect a level of a voltage in the USB data cable. 
     According to another aspect of the present disclosure, a method for controlling a power supply system may include: determining whether a device is connected at a first time point and at a second time point; determining a specification for supplying power based on whether the device is connected at the first time point and on whether the device is connected at the second time point; and supplying power based on the specification for supplying power. 
     The determining of the specification for supplying power may include: receiving the signal to request a voltage change to change the specification for supplying power, if it is determined that the device is connected at the first time point and that the device is disconnected at the second time point. 
     The determining of the specification for supplying power may include: maintaining the specification for supplying power, if it is determined that the device is connected at the first time point and that the device is connected at the second time point. 
     According to another aspect of the present disclosure, a power supply device may include: a USB data cable; a device information recognition unit that includes voltage-dividing resistors and receives a signal to request a voltage change from a target device via the USB data cable; and an output-voltage-changing unit that changes an output voltage based on the signal to request a voltage change. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The above and other aspects, features and other advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    is a diagram of a power supply system according to an exemplary embodiment of the present disclosure; 
         FIG.  2    is a diagram of a power supply system according to another exemplary embodiment of the present disclosure; 
         FIG.  3    is a diagram of a power supply system according to another exemplary embodiment of the present disclosure; 
         FIG.  4    is a diagram of a power supply system according to another exemplary embodiment of the present disclosure; 
         FIG.  5    is a diagram of a power supply system according to another exemplary embodiment of the present disclosure; 
         FIG.  6    is a diagram of a power supply system according to another exemplary embodiment of the present disclosure; 
         FIG.  7    is a diagram of a power supply system according to another exemplary embodiment of the present disclosure; 
         FIG.  8    is a diagram of a power supply system according to another exemplary embodiment of the present disclosure; 
         FIG.  9    is a flowchart for illustrating a method for controlling a power supply system according to an exemplary embodiment of the present disclosure; and 
         FIG.  10    is a circuit diagram of an adapter according to another exemplary embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Throughout the drawings, the same or like reference numerals will be used to designate the same or like elements. 
       FIG.  1    is a diagram of a power supply system according to an exemplary embodiment of the present disclosure. 
     Referring to  FIG.  1   , the power supply system may include an adapter  100 , and a target device  200 . 
     The target device  200  may be an electronic device which receives power from the adapter  100  to charge a battery therein. 
     The target device  200  may include an adapter connection switch  210 , a voltage detection unit  230 , a voltage-change-requesting unit  220 , a control unit  240 , and an analog-to-digital converter (ADC)  250 . 
     The control unit  240  may be operably connected to the adapter connection switch  210 , the voltage detection unit  230 , the voltage-change-requesting unit  220 , and the ADC  250 , so that it may control the adapter connection switch  210 , the voltage detection unit  230 , the voltage-change-requesting unit  220 , and the ADC  250 . 
     The adapter connection switch  210  may receive adapter recognition information and may form a connection with an adapter. The adapter recognition information may include information as to whether an adapter is connected to a target device. 
     That is, if an adapter is connected to a target device, the target device recognizes that the device connected thereto is an adapter and then may switch on the adapter connection switch. For example, the target device may recognize that the connected device is an adapter based on information on a USB data cable. 
     The voltage detection unit  230  may receive an output voltage from an adapter. The voltage detection unit  230  may include voltage-dividing resistors R 11  and R 12 . The voltage detection unit  230  may detect an output voltage Vo from an adapter divided by the voltage-dividing resistors R 11  and R 12 . 
     In this manner, the target device may receive the output voltage from the adapter. 
     The control unit  240  may check whether the output voltage from an adapter is equal to the rated voltage of the target device. If the output voltage from the adapter is equal to the rated voltage of the target device, a pass switch Qp is turned on so that a battery may be supplied with power. 
     If the output voltage from the adapter is not equal to the rated voltage of the target device, the target device  200  may output a signal to request a voltage change to the adapter  100 . 
     The voltage-change-requesting unit  220  may output the signal to request a voltage change based on the output voltage from the adapter. That is, the voltage-change-requesting unit  220  may output a voltage to request a voltage change based on the output voltage from the adapter. 
     The voltage-change-requesting unit  220  may include a resistor and a switch Q 11 . The switch Q 11  may be connected between ground and a connection node between the adapter connection switch  210  and the ADC  250 . Depending on switching of the switch Q 11 , the level of the voltage output from the voltage-change-requesting unit may be changed. 
     The adapter  100  may be connected to the target device  200  via a USB data cable V DATA . Further, the voltage-change-requesting unit  220  in the device may be connected to a device information recognition unit  140  in the adapter via the adapter connection switch  210  and the USB data cable V DATA . 
     The voltage-change-requesting unit  220  may output the signal to request a voltage change and the voltage to request a voltage change via the USB data cable V DATA . 
     As described above, in the power supply system according to the exemplary embodiment of the present disclosure, information can be transmitted between the adapter and the target device via the existing USB data cable V DATA , without employing any additional signal cable. 
     The ADC  250  may receive a signal from the voltage detection unit  230  and the adapter connection switch  210  and may transmit it to the control unit. 
     The adapter  100  may include a power supply unit, an output unit  110 , an output-voltage-changing unit  120 , a control unit  130 , the device information recognition unit  140 , and a low-dropout regulator (LDO)  150 . 
     The power supply unit may change input power into driving power having a predetermined voltage level so as to supply it. 
     The output unit  110  may change the voltage of the power from the power supply unit. The power with changed voltage may be regulated via a voltage regulator SR, in which a reference voltage is set by resistors R 1  and R 2 , and then it is output. 
     The device information recognition unit  140  may receive a signal to request a voltage change from the target device. Specifically, the device information recognition unit  140  may detect a change in the level of the voltage output from the voltage-change-requesting unit in the target device. In other words, the device information recognition unit  140  may detect a change in the voltage on the USB data cable V DATA . 
     The device information recognition unit  140  may include voltage-dividing resistors R 5  and R 6 . The device information recognition unit  140  may detect the voltage on the USB data cable which has been divided by the voltage-dividing resistors R 5  and R 6 . 
     The output-voltage-changing unit  120  may change the output voltage based on the signal to request a voltage change. 
     The output-voltage-changing unit  120  may include resistors R 4  and R 5  and a switch Q 1 . The resistor R 4  may be connected to the output unit  110  in parallel. 
     Depending on switching of the switch Q 1 , the level of the voltage output from the adapter may be changed. 
     The control unit  130  may be operably connected to the device information recognition unit  140  and to the output-voltage-changing unit and may control the device information recognition unit  140  and the output-voltage-changing unit. 
       FIG.  2    is a diagram of a power supply system according to another exemplary embodiment of the present disclosure. 
     The power supply system shown in  FIG.  2    is identical to the system shown in  FIG.  1   , except for the control unit  130 . Other elements than the control unit  130  have been described above and, therefore, will not be described again. 
     Referring to  FIG.  2   , the control unit  130  may replace the device information recognition unit  140  shown in  FIG.  1   . According to this exemplary embodiment, the resistors used in the device information recognition unit  140  are eliminated, and device information is recognized by resistors in the control unit  130 . Therefore, the number of used resistors may be reduced. 
       FIG.  3    is a diagram of a power supply system according to another exemplary embodiment of the present disclosure. 
     The power supply system shown in  FIG.  3    is identical to the system shown in  FIG.  1   , except for the control unit  130 . Other elements than the control unit  130  have been described above and, therefore, will not be described again. 
     The control unit  130  may include a plurality of comparators and a NAND logic circuit. The control unit  130  may output different signals when it receives a voltage within a predetermined range, i.e., V REF−  and V REF+  and when it receives a voltage out of the predetermined range, i.e., V REF−  and V REF+ . 
     Accordingly, the control unit  130  may not operate the output-voltage-changing unit  120  while the target device is being supplied with a rated voltage. Further, the control unit  130  may operate the output-voltage-changing unit  120  while the target device is not being supplied with a rated voltage. 
       FIG.  4    is a diagram of a power supply system according to another exemplary embodiment of the present disclosure. 
     The power supply system shown in  FIG.  4    is identical to the system shown in  FIG.  1   , except for the voltage-change-requesting unit  220 . Other elements than the voltage-change-requesting unit  220  have been described above and, therefore, will not be described again. 
     The voltage-change-requesting unit  220  may include a resistor and a switch Q 11 . The switch Q 11  may be connected between an output cable Vo and a connection node between the adapter connection switch  210  and the ADC  250 . Depending on switching of the switch Q 11 , the level of the voltage output from the voltage-change-requesting unit may be changed. 
       FIG.  5    is a diagram of a power supply system according to another exemplary embodiment of the present disclosure. 
     The power supply system shown in  FIG.  5    is identical to the system shown in  FIG.  4   , except for the control unit  130 . Other elements than the control unit  130  have been described above and, therefore, will not be described again. 
     Referring to  FIG.  5   , the control unit  130  may replace the device information recognition unit  140  shown in  FIG.  4   . According to this exemplary embodiment, the resistors used in the device information recognition unit  140  are eliminated, and device information is recognized by resistors in the control unit  130 . Therefore, the number of used resistors may be reduced. 
       FIG.  6    is a diagram of a power supply system according to another exemplary embodiment of the present disclosure. 
     The configuration of the power supply system shown in  FIG.  6    will be apparent to those skilled in the art based on the descriptions given with respect to the  FIGS.  1 ,  2 ,  3  and  4    and, therefore, will not be described. 
       FIG.  7    is a diagram of a power supply system according to another exemplary embodiment of the present disclosure. 
     The power supply system shown in  FIG.  7    is identical to the system shown in  FIG.  1   , except for an adapter information output unit  160 . Other elements than the adapter information output unit  160  have been described above and, therefore, will not be described again. 
     The adapter information output unit  160  may output adapter information to a target device. The adapter information may indicate that the adapter is a variable-output adapter. 
     When an adapter is connected to a target device, the adapter information output unit  160  may output adapter information to the target device. 
     The adapter information output unit  160  may include a resistor and a switch Q 2 . The switch Q 2  and the resistor may be connected to each other in series and may be connected to the device information recognition unit  140  in parallel. 
     Depending on switching of the switch Q 2 , the level of the voltage on a USB data cable V DATA  may be changed. 
     Accordingly, the adapter information output unit  160  may deliver the adapter information to the target device via the USB data cable V DATA . 
     As described above, in the power supply system according to the exemplary embodiment of the present disclosure, information can be transmitted between the adapter and the target device via the existing USB data cable V DATA , without employing any additional signal cable. 
       FIG.  8    is a diagram of a power supply system according to another exemplary embodiment of the present disclosure. 
     The power supply system shown in  FIG.  8    is identical to the system shown in  FIG.  7   , except for the control unit  130 . Other elements than the control unit  130  have been described above and, therefore, will not be described again. 
     Referring to  FIG.  8   , the control unit  130  may replace the device information recognition unit  140  shown in  FIG.  7   . According to this exemplary embodiment, the resistors used in the device information recognition unit  140  are eliminated, and device information is recognized by resistors in the control unit  130 . Therefore, the number of used resistors may be reduced. 
     In this regard, the control unit  130  shown in  FIGS.  1 ,  2 ,  4 ,  5 ,  7  and  8    may be a controller in the adapter to transmit/receive signals and to change an output voltage. 
     Further, the control unit  240  shown in  FIGS.  1 ,  2 ,  4 ,  5 ,  7  and  8    may be an IC to implement the inherent function of the device or may be a separate IC to perform voltage detection, voltage-change request or the like, as described above. 
     The control unit  130  shown in  FIGS.  3  and  6    may be implemented in an analog manner and may diversify output voltage by adding circuits such as a comparator, a logic gate, a flip-flop and the like if more voltages are required by the device. 
       FIG.  10    is a circuit diagram of an adapter according to another exemplary embodiment of the present disclosure. 
     The adapter shown in  FIG.  10    is identical to the adapter shown in  FIG.  1   , except for a disconnection-detecting unit  170 . Other elements than the disconnection-detecting unit  170  have been described above and, therefore, will not be described again. 
     The disconnection-detecting unit  170  may include a diode D DIS , resistors and a capacitor. 
     The level of the average input voltage of the diode D DIS  may be different depending on the state of a target device. Depending on the state of the device, the duty cycle of and frequency of a DC/DC converter are changed, and accordingly the average input voltage of the diode D DIS  may be changed. 
     After the average input voltage is rectified by the diode D DIS , it is filtered by the capacitor having small capacitance, and then a DC value reflecting the state of a load may be detected. By using this value, disconnection of the device can be detected. 
       FIG.  9    is a flowchart for illustrating a method for controlling a power supply system according to an exemplary embodiment of the present disclosure. 
     Referring to  FIG.  10   , the adapter may check whether the device is disconnected therefrom (S 10 ). In doing so, the disconnection-detecting unit  170  shown in  FIG.  9    may be used. 
     If it the adapter is disconnected from the device, the adapter may output base output power (S 20 ). 
     If the adapter is connected to the device, the adapter may check whether the adapter was disconnected from the device at a previous time point (S 30 ). 
     That is, according to the method for controlling a power supply system according to the exemplary embodiment of the present disclosure, it may be determined whether the device is connected to the adapter at first and second time points. The second time point is earlier than the first time point. 
     If the adapter is connected to the device at the first time point and at the second time point, the adapter does not change its output voltage. 
     In the related art, while an adapter supplies power to a device after they are connected to each other and mutually check recognition signals, the recognition signals may be distorted due to a change in the state of the device or introduction of noise. When this happens, the adapter may supply power to the device based on the erroneously recognized signal. At this time, an error occurs in the device and the device may be damaged, unless a separate protection circuit is operated in the device. 
     In the method for controlling a power supply system according to the exemplary embodiment of the present disclosure, however, it is determined whether the device is connected at the first time point and the second time point, and then it is determined whether to change the output power. Therefore, the specification for supplying power is not changed, even if distortion in a recognition signal or a reception error occurs, until a previously connected device is disconnected from an adapter and then another device having different specification is connected to the adapter. Additionally, damage to the device due to excessive power supplied thereto can be prevented. 
     If the adapter is connected to the device at the first time point and is disconnected from the device at the second time point, the adapter may detect a device recognition signal (S 40 ). The device recognition signal refers to the signal to request a voltage change, which is described above. 
     According to an exemplary embodiment of the present disclosure, the adapter may change the specification for supplying power based on the device recognition signal (S 50  and S 60 ). 
     According to the method for controlling a power supply system, errors in supplying power caused by erroneously recognizing signals can be reduced. Further, according to the method for controlling a power supply system, operational stability of a general-purpose power supply device can be improved. 
     In addition, the method for controlling a power supply system according to the exemplary embodiment does not require any additional cable and thus can save cost. 
     As set forth above, according to exemplary embodiments of the present disclosure, a general-purpose power supply system that can be used for a variety of devices having different voltage and current levels of driving power can be provided. 
     While exemplary embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations could be made without departing from the spirit and scope of the present disclosure as defined by the appended claims.