Abstract:
A device which includes interfaces, a measurement unit, a switching unit, and a control unit is used to parcel out charging currents to other chargeable devices, and allow partial charging of certain devices when full power is not available. The interfaces are connected to the chargeable devices. The measurement unit is connected to the power supply unit and the interfaces, and obtains a maximum supply current of the power supply unit and charging currents for the chargeable devices. The switching unit is connected between the measurement unit and the interfaces. The control unit is connected to the measurement unit and the switching unit, and selectively allows charging of the chargeable devices by controlling the switching unit according to the maximum supply current and the charging currents required.

Description:
FIELD 
       [0001]    The subject matter herein generally relates to mobile devices and methods of managing charging current. 
       BACKGROUND 
       [0002]    Mobile devices, such as mobile phones, mobile power supply units, pocket personal computers, and personal digital assistants (PDA) need to be charged or recharged. When a conventional external power supply is utilized to charge a plurality of mobile devices, it is not able to simultaneously charge the plurality of mobile devices with individual control of the charging. 
       SUMMARY 
       [0003]    In one aspect of the disclosure, a mobile device includes a plurality of interfaces, a measurement unit, a switching unit, and a control unit. The interfaces are coupled to electrical devices which require charging (chargeable devices). The measurement unit is coupled to the power supply unit and the interfaces, and obtains a maximum supply current of the power supply unit and charging currents for the chargeable devices. The switching unit is coupled between the measurement unit and the interfaces. The control unit is coupled to the measurement unit and the switching unit, and selectively charges the chargeable devices by controlling the switching unit according to the maximum supply current and the charging currents. 
         [0004]    In one aspect of the disclosure, a method of managing charging current applied in a mobile device which is coupled to a power supply unit and a plurality of chargeable devices comprises obtaining a maximum supply current of the power supply unit and charging currents for the chargeable devices, and selectively charging the chargeable devices according to the maximum supply current and the charging currents relevant to each chargeable device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    Implementations of the present technology will now be described, by way of example only, with reference to the attached figures, wherein: 
           [0006]      FIG. 1  is a block diagram of a mobile device according to an embodiment of the disclosure; 
           [0007]      FIG. 2  is a circuit diagram of the current measurement unit in  FIG. 1  according to an embodiment of the disclosure; 
           [0008]      FIG. 3  is a circuit diagram of the loading measurement unit shown in  FIG. 1  according to an embodiment of the disclosure; and 
           [0009]      FIG. 4  is a flowchart of a method of managing charging currents according to an embodiment of the disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features of the present disclosure. 
         [0011]    Several definitions that apply throughout this disclosure will now be presented. 
         [0012]    The term “coupled” is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The connection can be such that the objects are permanently connected or releasably connected. The term “comprising,” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series and the like. 
         [0013]    In the described embodiments, the direction of the arrow indicates the path of a signal. 
         [0014]      FIG. 1  shows a mobile device  10  according to an embodiment of the disclosure. In an embodiment, the mobile device  10  comprises a port  100 , a measurement unit  102 , a control unit  104 , a switching unit  106 , a feedback unit  108 , and a plurality of interfaces  111 - 11   n.  The mobile device  10  is electrically connected to an external power supply unit through the port  100 . 
         [0015]    The interfaces include a first interface  111 , a second interface  112 , and an nth interface  11   n.  The interfaces can be electrically connected to external chargeable devices. The external chargeable devices may comprise a battery  110  of the mobile device  10  and external devices such as mobile phones, mobile power supply units, pocket personal computers, and personal digital assistants. The mobile device  10  charges the external devices through the interfaces  111 - 11   n.  In an embodiment, the battery  110  of the mobile device  10  is electrically connected to the first interface  111 . 
         [0016]    The measurement unit  102  is electrically connected to the port  100 , and obtains the maximum supply current of the external power supply unit. In an embodiment, the measurement unit  102  may comprise a current measurement unit  1022  and a loading measurement unit  1024 . The current measurement unit  1022  is electrically connected between the port  100  and the switching unit  106 , to obtain the charging currents for the battery  110  and the external devices to be charged. The loading measurement unit  1024  is electrically connected to the connection point between the current measurement unit  1022  and the switching unit  106 , to obtain the maximum supply current of the external power supply unit. The current measurement unit  1022  and the loading measurement unit  1024  are electrically connected to the control unit  104 , and transmit the obtained charging currents and the maximum supply current to the control unit  104 . 
         [0017]    The switching unit  106  is electrically connected to the measurement unit  102  and the interfaces  111 - 11   n.  The charging path between the switching unit  106  and the first interface  111  is the first path  131 , the charging path between the switching unit  106  and the second interface  112  is the second path  132 , and the charging path between the switching unit  106  and the nth interface  11   n  is the nth path  13   n.  The control unit  104  is electrically connected to the measurement unit  102  and switching unit  106 . 
         [0018]    The control unit  104  is electrically connected to the measurement unit  102  and the switching unit  106 . The control unit  104  controls the connection status of the switching unit  106  to selectively charge the external chargeable devices according to the maximum supply current obtained by the measurement unit  102 . In an embodiment, the control unit  104  compares the maximum supply current of the external power supply unit with a predetermined value. The predetermined value can be a minimum value. The control unit  104  connects the charging paths between the measurement unit  102  and any of the interfaces  111 - 11   n  when the maximum supply current of the external power supply unit exceeds the predetermined value, and controls the measurement unit  102  to obtain the charging currents for the battery  110  and the external devices to be charged. 
         [0019]    The control unit  104  compares a total current of the charging currents for the battery  110  and the external chargeable devices with the maximum supply current of the external power supply unit. The charging currents for the battery  110  and the external chargeable devices are decreased proportionately when the total of the charging currents required exceeds the maximum supply current. In an embodiment, the charging currents can be decreased one by one. One or more of the charging currents for the battery  110  and the external chargeable devices are kept at a lower level until the total current of the charging currents required is less or equal to the maximum supply current. Thus, the control unit  104  charges at least one of the battery  110  and each of the external chargeable devices by controlling the switching unit  106 . The control unit  104  charges one of the battery  110  and each external chargeable device when the maximum supply current is less than or equal to the predetermined value, and charges all the battery  110  and the external chargeable devices when the maximum supply current exceeds the total current of the charging currents required. 
         [0020]    In an embodiment, the maximum supply current of the external power supply unit can be 4 amps (A), the charging current of the battery  110  can be 2 A, the charging current of the first external device to be charged can be 1 A, and the charging current of the second external device to be charged can be 2 A. The control unit  104  may charge the battery  110  and the second external chargeable device by controlling the switching unit  106 . Thus, the external power supply unit can charge the battery  110  and an external device simultaneously, reducing the overall charging time and improving the charging efficiency. 
         [0021]    The feedback unit  108  is electrically connected to the interfaces  111 - 11   n  and the control unit  104 . The feedback unit  108  determines whether there is a short circuit or a reversed connection in the charging paths. The control unit  104  disconnects a charging path when there is a short circuit or a reversed connection in that charging path, to ensure safety. In addition, the feedback unit  108  obtains the charged status of the battery  110  and each external chargeable device for the control unit  104 . The charged status can be information that the battery  110  and the external chargeable devices, or one or more of them, are fully charged. 
         [0022]    In an embodiment, the interfaces  111 - 11   n  have different charging priorities. The control unit  104  controls the switching unit  106  to charge the external chargeable devices according to the order of charging priority of the corresponding interface. In this embodiment, the control unit  104  charges the battery  110  electrically connected to the first interface  111  first when the first interface  111  has the highest charging priority. 
         [0023]    In an embodiment, the current measurement unit  1022  comprises a first terminal A, a second terminal B, and a third terminal C. The loading measurement unit  1024  comprises a first terminal D and a second terminal E. The switching unit  106  comprises a first terminal F. 
         [0024]    The first terminal A of the current measurement unit  1022  is electrically connected to the port  100 , the second terminal B of the current measurement unit  1022  is electrically connected to the control unit  104 , and the third terminal C of the current measurement unit  1022  is electrically connected to the first terminal F of the switching unit  106 . The first terminal D of the loading measurement unit  1024  is electrically connected to the control unit  104 , and the second terminal E of the loading measurement unit  1024  is electrically connected to a connection point between the third terminal C of the current measurement unit  1022  and the first terminal F of the switching unit  106 . 
         [0025]      FIG. 2  shows a circuit diagram of the current measurement unit  1022  of the mobile device  10  in  FIG. 1  according to an embodiment of the disclosure. In an embodiment, the current measurement unit  1022  comprises resistors R 1 -R 6 , a capacitor C 1 , and a comparator U 1 . The resistor R 1  and the capacitor C 1  are electrically connected in parallel, and are electrically connected between the first terminal A and the third terminal C of the current measurement unit  1022 . The comparator U 1  comprises a non-inverting input terminal, an inverting input terminal, a first voltage input terminal, a second voltage input terminal, and an output terminal. The non-inverting input terminal is coupled to a connection point between the resistor R 1  and the power supply unit, the inverting input terminal is coupled to a connection point between the switching unit  106  and the resistor R 1 , and the output terminal is coupled to the control unit  104 . 
         [0026]    One terminal of the resistor R 2  is electrically connected to the non-inverting input terminal of the comparator U 1 , and another terminal of the resistor R 2  is electrically connected to a connection point between the first terminal A of the current measurement unit  1022  and the resistor R 1 . One terminal of the resistor R 4  is electrically connected to a connection point between the resistor R 2  and the comparator U 1 , and another terminal of the resistor R 4  is electrically connected to a connection point between the first voltage input terminal of the comparator U 1  and ground. 
         [0027]    The second voltage input terminal of the comparator U 1  is electrically connected to the voltage terminal having 5 volts (V). One terminal of the resistor R 3  is electrically connected to the inverting input terminal of the comparator U 1 , and another terminal of the resistor R 3  is electrically connected to a connection point between the third terminal C of the current measurement unit  1022  and the resistor R 1 . The output terminal of the comparator U 1  is electrically connected to the second terminal B of the current measurement unit  1022 . One terminal of the resistor R 5  is electrically connected to a connection point between the resistor R 3  and the inverting input terminal of the comparator U 1 . Another terminal of the resistor R 5  is electrically connected to a connection point between the output terminal of the comparator U 1  and the second terminal B of the current measurement unit  1022 . The resistor R 6  is electrically connected between the output terminal of the comparator U 1  and ground. 
         [0028]      FIG. 3  shows a circuit diagram of the loading measurement unit  1024  of the mobile device  10  in  FIG. 1  according to an embodiment of the disclosure. In an embodiment, the loading measurement unit  1024  comprises field-effect transistors M 1 -M 3 , diodes D 1 -D 3 , and resistors R 7 -R 9 . The field-effect transistor comprises a gate, a source, and a drain. The gates of the field-effect transistors M 1 -M 3  are electrically connected to the first terminal D of the loading measurement unit  1024 . The drains of the field-effect transistors M 1 -M 3  are electrically connected to the second terminal E of the loading measurement unit  1024 , and the sources of the field-effect transistors M 1 -M 3  are electrically connected to ground. 
         [0029]    The diodes D 1 -D 3  are electrically connected between the sources and the drains of the FETs M 1 -M 3 . The anodes of the diodes D 1 -D 3  are connected to the drains of the FETs M 1 -M 3 . The resistors R 7 -R 9  are connected between the sources of the FETs M 1 -M 3  and ground. 
         [0030]    The FETs M 1 -M 3  can be replaced by bipolar junction transistors, and the channels of the FETs M 1 -M 3  can be P-channel or N-channel depending on the conduction direction required. 
         [0031]      FIG. 4  shows a flowchart of a method of managing charging currents according to an embodiment of the disclosure. The method is applied to the mobile device  10  of  FIG. 1 , and is performed by the elements in  FIG. 1 . At block  400 , the measurement unit  102  obtains the maximum supply current of the external power supply unit, and the control unit  104  compares the maximum supply current of the external power supply unit with a predetermined value. When the maximum supply current of the external power supply unit exceeds the predetermined value, the process goes to block  402 . At block  402 , the feedback unit  108  determines whether there is a short circuit or a reversed connection in the charging paths ( 131 - 13   n ) of the mobile device  10 . When there is a short circuit or a reversed connection in the charging paths ( 131 - 13   n ), the process goes to block  414 . At block  414 , the control unit  104  disconnects the charging paths corresponding to the short circuit or a reversed connection. In an embodiment, the control unit  104  controls the switching unit  106  to cut off the power supply to the corresponding charging path. For example, when there is a short circuit in the charging path  132 , the control unit  104  controls the switching unit  106  to cut off the power supply to the charging path  132 . 
         [0032]    When the maximum supply current is determined less than or equal to the predetermined value at block  400 , the process goes to block  412 . At block  412 , the control unit  104  charges one of the chargeable devices by controlling the switching unit  106 . The chargeable devices may comprise the battery  110  and the external devices. For example, the control unit  104  may charges the battery  110  only, without charging other external devices. In another embodiment, at block  404 , when there is no short circuit or reversed connection among the charging paths, the measurement unit  102  obtains the charging currents for the battery  110  and the external devices to be charged. 
         [0033]    At block  406 , the control unit  104  compares a total current of the charging currents for the battery  110  and the external devices with the maximum supply current of the external power supply unit. When the total current of the charging currents for the battery  110  and the external devices exceeds the maximum supply current, the process goes to block  408 . At block  408 , the charging currents for the battery  110  and the external devices are decreased proportionately. In an embodiment, the charging currents can be decreased one by one. For example, the charging current corresponding to the charging path  13   n  can be decreased first, and if the total current of the charging currents for the battery  110  and the external devices still exceeds the maximum supply current, then the charging current corresponding to the charging path  13 (n−1) will be decreased. One or more of the charging currents for the battery  110  and the external devices are kept at a lower level until the total current of the charging currents required is less or equal to the maximum supply current. In an embodiment, one or more of the charging currents for the battery  110  and the external devices is decreased to zero. 
         [0034]    At block  410 , the mobile device  10  charges one or a part of the battery  110  and the external devices. That is, at least one of the battery  110  and the external devices are not being charged. At block  411 , the control unit  104  determines whether the battery  110  and the external devices are all fully charged. When the battery  110  and the external devices are not fully charged, the process goes to block  406  to compare the total current of the charging currents for the battery  110  and the external devices with the maximum supply current of the external power supply unit. At block  406 , when the total current of the charging currents for the battery  110  and the external devices is determined less than or equal to the maximum supply current of the external power supply unit, the process goes to block  416 . At block  416 , the mobile device  10  charges all the battery  110  and the external devices. At block  411 , when the battery  110  and the external devices are all determined fully charged, the process is completed. 
         [0035]    Accordingly, embodiments of the disclosure provide mobile devices and methods of managing charging current. The charging currents are managed to improve the charging efficiency. In addition, the external power supply unit can charge the battery  110  and the external devices simultaneously, reducing the overall charging time. In addition, the feedback mechanism also ensures the safety of the charging process. 
         [0036]    The embodiments shown and described above are only examples. Many details are often found in the art such as the other features of signal filtering and power regulating. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, especially in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the embodiments described above may be modified within the scope of the claims.