Patent Publication Number: US-2016226266-A1

Title: Fast charging power bank

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Taiwan application serial no. 104201415, filed on Jan. 29, 2015. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a power supply; more particularly, the invention relates to a fast charging power bank. 
     2. Description of Related Art 
     The rapid development of mobile apparatuses allows normal mobile apparatuses to be equipped with high-resolution screens, to take pictures, to display video clips, to access to a wireless internet connection, and so forth. Said functions of the mobile apparatuses often consume power of batteries in the mobile apparatuses at a fast pace. Users of the mobile apparatuses are frequently required to prepare an additional power bank for charging the mobile apparatus and avoiding depletion of power. 
     In general, the power bank often performs a charging action through one single micro universal serial bus (micro-USB) port. Subject to the specifications of the micro-USB port, the micro-USB port often encounters limitations on currents, which also poses an impact on the charging current of the power bank. In another aspect, the capacity of the existing power bank continues to increase and frequently reaches 5000 mAh or even 12000 mAh. If the power bank with the large capacity still performs the charging action by applying the charging current provided by one single micro-USB port, the charging time of the power bank may be excessively long, which may cause inconvenience to users. 
     SUMMARY OF THE INVENTION 
     The invention is directed to a fast charging power bank capable of increasing a charging current in the power bank to reduce charging time. 
     In an embodiment of the invention, a fast charging power bank that includes at least one battery, a plurality of input ports, and a charging control unit is provided. The charging control unit includes a plurality of input boosters and a charging control circuit. The input ports are configured to respectively receive a plurality of input powers as a plurality of charging powers from a plurality of external power supplies. The input boosters are connected to each other in parallel. Each of the input boosters is correspondingly connected to an independent one of the input ports to receive one of the charging powers. An output terminal of each of the input boosters is connected to each other and connected to a boost bus. The input boosters respectively step up voltages of the charging powers to output a boosting voltage and control a current of each of the charging powers, so as to provide more significant energy and charge the at least one battery. Each of the input boosters controls the current of each of the charging powers to balance the input powers and prevent overload of the input powers. The charging control circuit is connected between the boost bus and the at least one battery. The charging control circuit is configured to control the boost bus and convert the boosting voltage into a charging current. The charging control unit also outputs the charging current to the at least one battery, so as to charge the at least one battery. 
     According to an embodiment of the invention, the fast charging power bank further includes a measurement circuit and a processing circuit. The measurement circuit is connected to the at least one battery to measure a voltage and a current of the at least one battery and generate a measurement signal. The processing circuit is connected to the input boosters, the charging control circuit, and the measurement circuit. The input boosters are respectively controlled by the processing circuit to generate the boosting voltage and control the currents of the charging powers. The processing circuit receives a measurement signal and controls the charging control circuit based on the measurement signal, so as to generate the charging current. 
     According to an embodiment of the invention, the processing circuit of the fast charging power bank is further connected to the input ports to detect the charging powers. The processing circuit controls the input boosters based on a plurality of detection results of the charging powers, so as to control the currents of the charging powers and control the input boosters to generate the boosting voltage. 
     According to an embodiment of the invention, the processing circuit of the fast charging power bank obtains a maximum stable power output by each of the external power supplies according to the detection result of each of the charging powers. 
     According to an embodiment of the invention, the processing circuit of the fast charging power bank controls a current of each of the input boosters to adjust the charging current. 
     According to an embodiment of the invention, the fast charging power bank further includes a discharging control unit. The discharging control unit includes a battery booster and a discharging control circuit. The battery booster is connected to the at least one battery and the processing circuit. The battery booster is controlled by the processing circuit to step up the voltage of the at least one battery and accordingly generate a discharging voltage. The discharging control circuit is connected to the battery booster and the processing circuit. The discharging control circuit is controlled by the processing circuit to output the discharging voltage and at least one discharging current to at least one mobile apparatus. 
     According to an embodiment of the invention, the fast charging power bank further includes at least one output port. The at least one output port is connected to the discharging control circuit to output the power of the at least one battery after the voltage of the at least one battery is stepped up. Besides, the at least one output port outputs said power to the at least one mobile apparatus. The discharging control circuit detects the at least one discharging current to perform an overload detection on the at least one output port. 
     According to an embodiment of the invention, the processing circuit of the fast charging power bank obtains a current capacity of the at least one battery according to the measurement signal. If the current capacity of the at least one battery is greater than an input threshold, the processing circuit controls the charging control circuit to stop generating the charging current. If the current capacity of the at least one battery is less than a battery threshold, the processing circuit controls the discharging control circuit to stop charging the at least one mobile apparatus. 
     According to an embodiment of the invention, in the fast charging power bank, the input threshold is the maximum allowable capacity of the at least one battery, and the battery threshold is the minimum allowable capacity of the at least one battery. 
     According to an embodiment of the invention, each of the input ports or each of the at least one output port is a universal serial bus (USB) port, and the USB port is a micro-USB port, a mini-USB port, or a USB type C port. 
     In light of the foregoing, the fast charging power bank is able to receive the input powers from the external power supplies through the input ports, so as to add up the powers. Hence, large charging current can be provided to the at least one battery in the power bank. Thereby, the charging action performed on the at least one battery can be accelerated, and the charging time of the at least one battery can be reduced. Moreover, each input booster is connected to one independent input port corresponding to the input booster to receive the charging power; accordingly, the processing circuit is able to control the current of each input booster, so as to control the voltage at the boost bus and adjust the charging current of the at least one battery. 
     Several exemplary embodiments accompanied with figures are described in detail below to further describe the invention in details. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
         FIG. 1  is a schematic block diagram illustrating a fast charging power bank according to an embodiment of the invention. 
         FIG. 2  is a schematic block diagram illustrating details of the fast charging power bank depicted in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS 
     Descriptions of the invention are given with reference to the exemplary embodiments illustrated with accompanied drawings, wherein same or similar parts are denoted with same reference numerals. In addition, whenever possible, identical or similar reference numbers stand for identical or similar elements in the figures and the embodiments. 
       FIG. 1  is a schematic block diagram illustrating a fast charging power bank  1000  according to an embodiment of the invention. The fast charging power bank  1000  includes a battery  1100 , a plurality of input ports  1201 - 120   n , a charging control unit  1300 , a measurement circuit  1400 , a discharging control unit  1500 , a plurality of output ports  1601 - 160   m , and a processing circuit  1700 . 
     The battery  1100  may stand for one single battery (or a battery device), a battery set, or a module that includes one or more batteries (or battery devices). Besides, the battery  1100  may be a rechargeable battery, such as a nickel-zinc battery, a nickel-metal hydride (NiMH) battery, a lithium ion battery, a lithium polymer battery, or a LiFePO 4  battery, which should however not be construed as a limitation to the invention. 
     The input ports  1201 - 120   n  are configured to respectively receive a plurality of input powers PI_ 1 -PI_n as a plurality of charging powers SC_ 1 -SC_n from a plurality of external power supplies (not shown) and supply the charging powers SC_ 1 -SC_n to the charging control unit  1300 . In an embodiment of the invention, the input ports  1201 - 120   n  may be USB input ports, but the invention is not limited thereto. As provided above, the input ports  1201 - 120   n  may be of various types, e.g., micro-USB input ports, mini-USB input ports, USB type C connection ports, etc. 
     The charging control unit  1300  respectively steps up voltages of the charging powers SC_ 1 -SC_n (i.e., the input powers PI_ 1 -PI_n) and converts the voltages into charging current Ic. The charging control unit  1300  also outputs the charging current Ic to the battery  1100 , so as to charge the battery  1100 . 
     The measurement circuit  1400  is connected to the battery  1100  to measure a voltage and a current of the battery  1100  and generate a measurement signal Sm. 
     The discharging control unit  1500  is connected to the battery  1100 . After the discharging control unit  1500  steps up a voltage Vb of the battery  1100 , the discharging control unit  1500  outputs the voltage Vb to a load (not shown, e.g., a mobile apparatus) through the output ports  1601 - 160   m  to generate at least one of the discharging currents Id 1 -Idm. 
     The output ports  1601 - 160   m  are connected to the discharging control unit  1500  to receive the discharging currents Id 1 -Idm. The output ports  1601 - 160   m  output the discharging currents Id 1 -Idm to at least one mobile apparatus (not shown), so as to provide output powers PO_ 1 -PO_m to at least one external mobile apparatus. According to an embodiment of the invention, the mobile apparatus may be a cell phone, a tablet PC, and so forth, and the invention is not limited thereto. In an embodiment of the invention, the output ports  1601 - 160   m  may be USB output ports, which should not be construed as a limitation to the invention. As described above, the output ports  1601 - 160   m  may be USB output ports of various types, e.g., USB output ports, USB type C connection ports, and so forth. 
     The processing circuit  1700  is connected to the input ports  1201 - 120   n , the charging control unit  1300 , the measurement circuit  1400 , the discharging control unit  1500 , and the output ports  1601 - 160   m . The processing circuit  1700  is able to detect the charging powers SC_ 1 -SC_n from the input ports  1201 - 120   n , so as to detect whether the external power supply is connected to the input ports  1201 - 120   n . For instance, the input ports  1201 - 120   n  are the USB input ports; hence, when the external power supply is connected to the input port  1201 , the external power supply can provide the voltage (e.g., at 5 volts) of the charging power SC_ 1  to the processing circuit  1700  through the input port  1201 . Thereby, the processing circuit  1700  can detect whether the external power supply is connected to the input ports  1201 - 120   n  according to the voltages of the charging powers SC_ 1 -SC_n. Nevertheless, the invention should not be construed as limited to the embodiments set forth herein. 
     Besides, the processing circuit  1700  may learn the voltage and the current of the battery  1100  at present based on the measurement signal Sm generated by the measurement circuit  1400 . According to the measurement signal Sm, the processing circuit  1700  obtains a current capacity of the battery  1100 . If the current capacity of the battery  1100  is greater than an input threshold, the processing circuit  1700  controls the charging control unit  1300  to stop charging the battery  1100 . That is, the charging control unit  1300  stops generating the charging current Ic. Thereby, dangers resulting from the excessive charging of the battery  1100  by the charging control unit  1300  can be prevented. By contrast, if the current capacity of the battery  1100  is less than a battery threshold, the processing circuit  1700  controls the discharging control unit  1500  to stop charging the external apparatus. That is, the discharging control unit  1500  switches off the outputs. Thereby, damages to the battery  110  can be prevented because the excessive discharging of the battery  1100  by the discharging control unit  1500  can be avoided. Here, the input threshold is greater than the battery threshold. 
     According to an embodiment of the invention, the input threshold can be the maximum allowable capacity of the battery  1100 , and the battery threshold  1100  can be the minimum allowable capacity of the battery  1100 ; however, the invention is not limited thereto. In an embodiment of the invention, the maximum allowable capacity of the battery  1100  may be 100% of the capacity of the battery  1100 , and the minimum allowable capacity of the battery  1100  can be 0% of the capacity of the battery  1100 ; however, the invention is not limited thereto. 
     In the previous embodiment, the measurement circuit  1400  may include a coulomb meter to measure the current capacity of the battery  1100 . The measurement circuit  1400  may also be included in the processing circuit  1700 . That is, the processing circuit  1700  may perform a voltage measurement function or a capacity measurement function, which should not be construed as a limitation to the invention. 
     In the previous embodiment of the invention, the processing circuit  1700  may be implemented in form of a micro processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), or a field programmable gate array (FPGA). The charging control unit  1300 , the measurement circuit  1400 , and the discharging control unit  1500  may be implemented in form of ASIC or FPGA. Here, the charging control unit  1300 , the measurement circuit  1400 , and the discharging control unit  1500  may be respectively formed on one individual circuit chip or may be partly or wholly formed on one integrated circuit chip, which should however not be construed as a limitation to the invention. 
     Please refer to  FIG. 2 , which is a schematic block diagram illustrating details of the fast charging power bank  1000  depicted in  FIG. 1 . As shown in  FIG. 2 , the fast charging power bank  1000  includes the battery  1100 , the input ports  1201 - 120   n , the measurement circuit  1400 , the output ports  1601 - 160   m , and the processing circuit  1700 , and the descriptions of these elements are provided above and shown in  FIG. 1  and thus will not be further provided. The charging control unit  1300  will be further elaborated hereinafter. The description of the discharging control unit  1500  will then follow. 
     The charging control unit  1300  includes a plurality of input boosters  1311 - 131   n  and a charging control circuit  1330 . The input boosters  1311 - 131   n  are connected to each other in parallel. An input terminal of each of the input boosters  1311 - 131   n  is correspondingly connected to an independent one of the input ports  1201 - 120   n  to receive one of the charging powers SC_ 1 -SC_n. An output terminal of each of the input boosters  1311 - 131   n  is connected to each other and connected to a boost bus  1390 . The input boosters  1311 - 131   n  step up voltages of the charging powers SC —    1 -SC_n respectively and output a boosting voltage BoostV to the boost bus  1390 . Each of the input boosters  1311 - 131   n  controls the current of each of the charging powers SC_ 1 -SC —  to balance the input powers PI_ 1 -PI_n and prevent overload of the input powers PI_ 1 -PI_n. The charging control circuit  1330  is connected between the boost bus  1390  and the battery  1100 . The charging control circuit  1330  serves to receive the boosting voltage BoostV. Besides, the charging control circuit  1330  converts the boosting voltage BoostV into a charging current Ic and outputs the charging current Ic to the battery  1100 , so as to charge the battery  1100 . 
     Specifically, the input booster  1311  is correspondingly connected to an independent one of the input ports (e.g., the input port  1201 ) to receive one of the charging powers (e.g., the charging power SC_ 1 ). The input booster  1311  steps up the voltage of the charging power SC_ 1  to generate the boosting voltage BoostV and outputs the boosting voltage BoostV to the boost bus  1390 . Similarly, the input booster  1312  is correspondingly connected to an independent one of the input ports (e.g., the input port  1202 ) to receive one of the charging powers (e.g., the charging power SC_ 2 ). The input booster  1312  steps up the voltage of the charging power SC_ 2  to generate the boosting voltage BoostV and outputs the boosting voltage BoostV to the boost bus  1390 . Details of the other input boosters  1313 - 131   n  may be deduced from the above descriptions. Since the input boosters  1311 - 131   n  are connected to the charging control circuit  1330  in parallel through the boost bus  1390 , the charging control circuit  1330  is able to add up the currents provided by the input boosters  1311 - 131   n  to the boost bus  1390 . The charging control circuit  1330  is configured to convert the boosting voltage BoostV into the charging current Ic. 
     According to an embodiment of the invention, the processing circuit  1700  is connected to the input boosters  1311 - 131   n  and the charging control circuit  1330 . The processing circuit  1700  controls the input boosters  1311 - 131   n  based on a plurality of detection results of the charging powers SC_ 1 -SC_n, so as to allow the input boosters  1311 - 131   n  to generate the boosting voltage BoostV. The processing circuit  1700  controls the charging control circuit  1330  based on the measurement signal Sm, so as to generate the charging current Ic. In particular, as provided above, the processing circuit  1700  is able to detect whether the external power supply is connected to the input ports  1201 - 120   n  according to the charging powers SC_ 1 -SC_n. If the processing circuit  1700  determines the external power supply is connected to the input ports  1201 - 120   n , the processing circuit  1700  controls the input boosters  1311 - 131   n  respectively, so as to allow the input boosters  1311 - 131   n  to generate the boosting voltage BoostV. 
     For instance, it is assumed that the input port  1201  receives an input power PI_ 1  as the charging power SC_ 1  from an external power supply, the charging power SC_ 1  has the voltage at 5 volts and the current in 2 amperes (i.e., the power is 10 watts), the processing circuit  1700  controls the boosting voltage BoostV output by the input boosters  1311 - 131   n  to be at 10 volts, and the fully charged battery  1100  has the voltage at 4 volts. The processing circuit  1700  can determine the external power supply is connected to the input port  1201  according to the charging power SC_ 1 . Hence, the processing circuit  1700  is able to control the input booster  1311  to step up the voltage of the charging power SC_ 1 , so as to generate the boosting voltage BoostV. 
     In accordance with the Law of Conservation of Energy, after stepping up the voltage of the charging power SC_ 1  (e.g., to 10 volts), the input booster  1311  outputs the current at 1 ampere to the charging control circuit  1330 . The charging control circuit  1330  then converts the boosting voltage BoostV (at 10 volts) provided by the input booster  1311 . Since the voltage of the fully charged battery  1100  is 4 volts, the charging control circuit  1330  is required to step down the boosting voltage BoostV (at 10 volts). Similarly, in accordance with the Law of Conservation of Energy, the charging control circuit  1330  generates the charging current Ic at 2.5 amperes. That is, the charging control circuit  1330  charges the battery  1100  with the current at 2.5 amperes. 
     In view of the foregoing, another input port  1202  is assumed to receive the input power PI_ 2  as the charging power SC_ 2  from another external power supply, and the charging power SC_ 2  has the voltage at 5 volts and the current at 1 ampere (i.e., the power is 5 watts). The processing circuit  1700  can determine another external power supply is connected to the input port  1202  according to the charging power SC_ 2 . Hence, the processing circuit  1700  is able to control the input booster  1312  to step up the voltage of the charging power SC_ 2 , so as to generate the boosting voltage BoostV. 
     In accordance with the Law of Conservation of Energy, after stepping up the voltage of the charging power SC_ 2  (e.g., to 10 volts), the input booster  1312  outputs the current at 0.5 ampere to the charging control circuit  1330 . Since the input booster  1311  outputs the current at 1 ampere to the charging control circuit  1330 , the input boosters  1311  and  1312  in total provide the current at 1.5 ampere (i.e., 15 watts of power) to the charging control circuit  1330 . The charging control circuit  1330  then converts the boosting voltage BoostV (at 10 volts) provided by the input boosters  1311  and  1312 . Since the voltage of the fully charged battery  1100  is 4 volts, the charging control circuit  1330  is required to switch-step down the boosting voltage BoostV (at 10 volts). Similarly, in accordance with the Law of Conservation of Energy, the charging control circuit  1330  generates the charging current Ic at 3.75 amperes (obtained by dividing 4 volts from 15 watts). That is, the charging control circuit  1330  charges the battery  1100  with the current at 3.75 amperes. 
     As described above, the charging current provided to the battery  1100  of the power bank  1000  through plural input ports (e.g., simultaneously through the input ports  1201  and  1202 ) is greater than the charging current provided to the battery  1100  through one single input port (e.g., merely through the input port  1201 ). In other words, simultaneous use of plural input ports  1201 - 120   n  leads to an increase in the charging current of the battery  1100 , which significantly accelerates the charging action on the battery  1100  and reduces the time spent on fully charging the battery  1100 . Note that the conditions described above, i.e., the charging power SC_ 1  has the voltage at 5 volts and the current at 2 amperes, the charging power SC_ 21  has the voltage at 5 volts and the current at 1 ampere, the boosting voltage BoostV is 10 volts, and the voltage of the fully charged battery  1100  is 4 volts, are exemplary and should not be construed as limitations to the invention. 
     With reference to  FIG. 2 , the input boosters  1311 - 131   n  may be respectively controlled by the processing circuit  1700  to generate the stable boosting voltage BoostV, and thereby the input boosters  1311 - 131   n  are allowed to respectively adjust the current provided to the charging control circuit  1330 . 
     Said exemplary conditions are applied to further elaborate the invention. If the charging power SC_ 1  has the voltage at 5 volts and the current at 2 amperes, the input booster  1311  can be controlled by the processing circuit  1700  to generate the boosting voltage BoostV at 10 volts and output the current at 1 ampere to the charging control circuit  1330 . Under some circumstances, if the input power PI_ 1  (i.e., the charging power SC_ 1 ) provided by the external power supply is unstable, e.g., from 2 amperes down to 1.6 ampere, the processing circuit  1700  may control the input booster  1311  according to the detection result of the charging power SC_ 1 . Particularly, the processing circuit  1700  at this time can control the input booster  1311  to maintain the boosting voltage BoostV at 10 volts. However, the processing circuit  1700  controls the input booster  1311  to merely provide the current at 0.8 ampere to the charging control circuit  1330 . Detailed operations of the other input boosters  1312 - 131   n  may be deduced from the above descriptions. 
     Thereby, the processing circuit  1700  is able to learn the maximum stable power that can be provided by each external power supply (e.g., the external power supply connected to the input port  1201 ) according to the detection results of the charging powers SC_ 1 -SC_n (e.g., the charging power SC_ 1 ). In the above embodiment, the maximum stable power that can be output from the input booster  1311  or from the external power supply connected to the input port  1201  is 8 watts (obtained by multiplying 5 volts by 1.6 ampere or by multiplying 10 volts by 0.8 ampere). Since the processing circuit  1700  is able to learn the maximum stable power that can be output from the external power supplies connected to the input ports, the processing circuit  1700  can control the charging control circuit  1330  to generate the maximum stable charging current Ic. 
     In addition to the above, the processing circuit  1700  can further control each input booster to be switched on or off. For instance, when the processing circuit  1700  intends to raise the charging current of the battery  1100 , the processing circuit  1700  may simultaneously switch on plural input boosters (e.g., two or more) or switch on plural input boosters that are capable of providing large stable powers (e.g., at 10 watts). Thereby, the charging control circuit  1330  is able to add up the powers provided by the input boosters that are switched on, and the charging control circuit  1330  converts the powers into the charging currents for charging the battery  1100 . By contrast, the processing circuit  1700  can merely switch on one input booster or switch on the input booster that is capable of providing small stable powers (e.g., at 5 watts), so as to reduce the charging current of the battery  1100 . 
     The discharging control unit  1500  will be further elaborated hereinafter. As shown in  FIG. 2 , the discharging control unit  1500  includes a battery booster  1510  and a discharging control circuit  1530 . The battery booster  1510  is connected to the battery  1100  and the processing circuit  1700 . Besides, the battery booster  1510  is controlled by the processing circuit  1700  to step up the voltage Vb of the battery  1100  and accordingly generate a discharging voltage DV. The discharging control circuit  1530  is connected to the battery booster  1500 , the processing circuit  1700 , and at least one of the output ports  1601 - 160   m . Here, the discharging control circuit  1530  serves to receive the discharging voltage DV. The discharging control circuit  1530  is controlled by the processing circuit  1700 , so as to convert the discharging voltage DV into at least one discharging current Id 1 -Idm. The discharging control circuit  1530  then provides the at least one discharging current Id 1 -Idm to the output ports  1601 - 160   m . The discharging control circuit  1530  can detect the at least one discharging current Id 1 -Idm to perform an overload detection on the output ports  1601 - 160   m.    
     For instance, if the voltage Vb of the battery  1100  is 4 volts, and if the processing circuit  1700  detects that one mobile apparatus (not shown) is connected to the output port  1601 , the processing circuit  1700  can control the battery booster  1510  to step up the voltage Vb (at 4 volts) of the battery  1100 , so as to generate the discharging voltage DV (e.g., at 5 volts, the USB voltage level). The discharging control circuit  1530  converts the discharging voltage DV into the discharging current Id 1 . Thereby, the discharging current Id 1  can be provided to the mobile apparatus through the output port  1601 . 
     To sum up, the fast charging power bank provided herein is able to receive the input powers as the charging powers from the external power supplies through the input ports. Hence, large charging current can be provided to the battery in the power bank. Thereby, the charging action performed on the battery can be accelerated, and the charging time of the battery can be reduced. Moreover, each input booster is connected to one independent input port corresponding to the input booster to receive the charging power; accordingly, the processing circuit is able to control each input booster to be switched on or off, so as to control the charging current of the battery. 
     Although the invention has been described with reference to the above embodiments, it will be apparent to one of ordinary skill in the art that modifications to the described embodiments may be made without departing from the spirit of the invention. Accordingly, the scope of the invention will be defined by the attached claims and not by the above detailed descriptions.