Abstract:
A power charging system for charging portable electric devices. The power charging system includes a plurality of transformers for transforming a plurality of different input voltages into a standard DC (direct current) voltage. The charging system also includes a power cord for inputting and outputting the standard DC voltage. The charging system also includes a plurality of converters for converting the standard DC voltage into the working voltage of the portable electric devices. Users connect the corresponding converters to the power cord and then connect the power cord to any one of the transformers to use the standard DC voltage to charge the portable electric devices.

Description:
BACKGROUND OF INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a power charging system, and more particularly, to a power charging system for portable electric devices.  
           [0003]    2. Description of the Prior Art  
           [0004]    In modern society, many people carry portable electric devices, such as a mobile phone, a PDA (personal digital assistant), a hand-held computer, a notebook computer, and so on. Many users carry two or more of these portable devices to access electrical data and interchange information with others. A charging system including a transformer and power cord designed for each portable electric device allows usage of these portable electric devices anytime and anywhere.  
           [0005]    The convenience of portable electric devices becomes a disadvantage when users have to carry two or even more (depending on how many portable electric devices they carry) charging systems with them to charge their different portable electric devices. Please refer to FIG. 1. FIG. 1 is a schematic diagram illustrating a portable electric device  10 A charging system according to prior art. The portable electric device  10 A has a charging port  12 A for inputting a DC (direct current) working voltage. Two corresponding transformers  16 A and  18 A are used to charge the portable electric device  10 A. An AC (alternating current) power  20  is input via an input port  17 A of the transformer  16 A, altered by the transformer  16 A to the working voltage of the portable electric device  10 A, and output via an output port  14 A of the transformer  16 A. In a similar manner, a DC power  22  is input via an input port  19 A of the transformer  18 A, altered to the working voltage of the portable electric device  10 A, and output via an output port  15 A of the transformer  18 A. Users can select the transformer  16 A or  18 A to charge the portable electric device  10 A by connecting the input port of the transformer to a corresponding power source and connecting the output port of the transformer to the charging port  12 A of the portable electric device  10 A. In conclusion, an input power is first transformed into the specially designed working voltage of a portable device by a corresponding transformer, delivered from the output port of the transformer to the corresponding charging port of the portable electric device, and is finally used to charge the portable electric device.  
           [0006]    According to a similar prior art, a portable electric device  10 B, shown in FIG. 1, also has a specially designed charging port  12 B for inputting its specially designed working voltage. The transformers  16 B and  18 B respectively have corresponding output ports  14 B and  15 B. An AC power  20  is input via an input port  17 B of the transformer  16 B, altered by the transformer  16 B into the specially designed working voltage of the portable electric device  10 B, and output to the charging port  12 B via the output port  14 B of the transformer  17 B. Similarly, a DC power  22  is input via an input port  19 B of the transformer  18 B, altered to the specially designed working voltage of the portable electric device  10 B, and output to the charging port  12 B via the output port  15 B of the transformer  18 B.  
           [0007]    Different portable electric devices have different specially designed working voltages. For example, the working voltage of modern portable electric devices varies from 3 volts to 12 volts. The charging port of each portable electric device also has a different shape and structure. A prior art portable electric device is equipped with its own specially designed transformer. These special transformers convert an input power via their input ports into the specially designed working voltage of the corresponding portable electric device. The output ports of these transformers must match the specially designed charging port of the portable electric device. Thus, when users carry two (or even more) portable electric devices, they have to carry corresponding specially designed transformers to charge their portable electric devices.  
           [0008]    According to the prior art shown in FIG. 1, although the transformers  16 A and  16 B both can transform the AC power  20  to DC power, the transformed voltages that are output from each transformer are still the two specially designed and often different working voltages of the portable electric devices  10 A and  10 B. The output ports  14 A and  14 B of the transformers  16 A and  16 B also have different shapes. These two reasons make the specially designed transformer  16 A of the portable electric device  10 A incompatible with the portable electric device  10 B. Likewise, the specially designed transformer  16 B of the portable electric device  10 B cannot charge the portable electric device  10 A.  
           [0009]    If users plan to charge a portable electric device with two different kinds of power sources, they have to carry at least two different specially designed transformers for each portable electric device to transform different power sources into the specially designed working voltage of the portable electric device. As shown in FIG. 1, users have to carry the two specially designed transformers  16 A and  18 A with them to charge the portable electric device  10 A from two different power sources, the DC power  22  and the AC power  20 .  
           [0010]    A disadvantage of prior art is that users have to carry each specially designed transformer for each portable electric device to charge the portable electric device. It is obviously quite inconvenient for users to carry every possible charging combination for every portable electric device that they carry. Moreover, the weight and the volume of the transformers  16 A or  16 B, used in transforming AC power to DC power, is hard to further reduce. Additionally, it is also difficult to store power cords (power cords  21 A and  23 A of the transformers  16 A and  18 A) because of their lengths. Any portable electric device needs to be equipped with every kind of specially designed transformer to charge from different power sources, increasing the cost of portable electric devices and restricting the development of the information industry.  
         SUMMARY OF INVENTION  
         [0011]    It is therefore a primary objective of the claimed invention to provide a single power charging system to charge a plurality of portable electric devices so as to solve the above mentioned problems.  
           [0012]    According to the claimed invention, the charging system for charging a plurality of portable devices includes a corresponding charging port for inputting a working voltage, each of the portable devices having a different working voltage. The charging system includes a plurality of transformers for converting a plurality of different input voltages into a standard DC (direct current) voltage. Each of the transformers has an output port for outputting the standard DC voltage. The charging system includes a power cord that includes a first connection end removably connected to the output port of the transformer for inputting the standard DC voltage and a second connection end for outputting the standard DC voltage. The charging system also includes a plurality of converters to change the standard DC voltage into the corresponding working voltages of the plurality of portable devices. Each of the converters includes an input port removably connected to the second connection end of the power cord for receiving the standard DC voltage and an output port removably connected to the charging port of a portable device for outputting the working voltage of the portable device. When charging portable devices, users can connect the power cord to the corresponding converter and to any one of the transformers, using the standard DC voltage to charge the plurality of the portable devices.  
           [0013]    It is an advantage of the claimed invention that a single power charging system can charge a plurality of portable electric devices.  
           [0014]    These and other objectives of the claimed invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0015]    [0015]FIG. 1 is a schematic diagram of a charging system of a portable electric device according to the prior art.  
         [0016]    [0016]FIG. 2 is a schematic diagram of a charging system of a portable electric device according to the present invention.  
         [0017]    [0017]FIG. 3 is a state diagram of a combination of a power source, a transformer, a power cord, a converter, and a portable electric device shown in FIG. 2. 
     
    
     DETAILED DESCRIPTION  
       [0018]    Please refer to FIG. 2. FIG. 2 is a schematic diagram illustrating a charging system  30  according to the present invention. Portable electric devices  10 A and  10 B have corresponding charging ports  50 A and  50 B for inputting a specially designed DC working voltage into the portable electric devices. The portable electric device can be a mobile phone, a PDA, or obviously nearly any device requiring a DC working voltage. Only two portable electric devices are shown in FIG. 2 allowing easy explanation of this embodiment.  
         [0019]    The charging system  30  according to the present invention comprises transformers  32 A,  32 B,  32 C corresponding to respective power supplies and converters  42 A and  42 B corresponding to the respective portable electric devices. The transformers  32 A,  32 B, and  32 C correspond to different power supply sources. The converters  42 A and  42 B correspond respectively to the portable electric devices  10 A and  10 B. A power cord  40 , removably connected between a transformer and a converter, transmits a standard DC voltage generated by a transformer to a converter.  
         [0020]    In this preferred embodiment, a housing of the transformer is made of a hard plastic. That is, the transformer comprises a hard cubic structure and is easy to carry. Each transformer comprises a standard outputinstalled on the housing. The preferred embodiment, shown in FIG. 2, shows that the transformer  32 A alters the power of a battery  35  into the standard DC voltage and outputs the transformed power via an output port  34 A. The transformer  32 B transforms an AC power  20 , input via an input port  36 B, into the standard DC voltage and outputs the transformed power via an output port  34 B. The transformer  32 C changes a DC power  22 (for example, provided by a car or an airplane), input via an input port  36 C, into a standard DC voltage and outputs the transformed power via an output port  34 C. According to the present invention, a different transformer alters each kind of input power into the standard DC voltage and outputs the transformed power via a standard output port. In another words, the shape of the transformers“ 32 A,  32 B and  32 C output ports  34 A,  34 B and  34 C are the same. The standard DC voltages output via the output ports  34 A,  34 B and  34 C are also the same.  
         [0021]    The charging system  30  according to the present invention has a corresponding converter for each portable electric device. Each converter comprises an input port and an output port. Each input port receives a standard DC voltage, but each output port corresponds to a different specially designed charging port of a portable electric device. Each converter inputs a standard DC voltage via an input port  46 A or  46 B, transforms the input power into a specially designed working voltage of the corresponding portable electric device, and outputs the transformed voltage via an output port  48 A or  48 B. As shown in FIG. 2, the converters  42 A and  42 B correspond respectively to the portable electric devices  10 A and  10 B.  
         [0022]    The converters”  42 A and  42 B respective input ports  46 A and  46 B are standardized. The output port  48 A of the converter  42 A corresponds to the charging port  50 A of the portable electric device  10 A. The converter  42 A transforms the standard DC voltage into the specially designed working voltage of the portable electric device  10 A and outputs the transformed voltage via the output port  48 A. In the same manner, the output port  48 B of the converter  42 B corresponds to the charging port  50 B of the portable electric device  10 B. The converter  42 B transforms the standard DC voltage into the specially designed working voltage of the portable electric device  10 B and outputs the transformed voltage via the output port  48 B.  
         [0023]    According to the present invention, the power cord  40  transmits electric power between the transformers  32 A,  32 B and  32 C and the converters  42 A and  42 B. The power cord  40  has a first connection end  45  and a second connection end  43 . The first connection end  45  can removably connect to the output port of each transformer. The second connection end  43  can removably connect to the input port of each converter. According to the present invention, the first connection end  45  conforms to the same standard as that of the second connection end  43 , making the connection ends  43  and  45  of the power cord  40  interchangeable. The output port of the transformer can be a standard USB, RS232, PS2, or 1394 interface. The corresponding power cord  40 , of course, must have the same standard.  
         [0024]    An operation of the charging system  30  according to the present invention can be described as follows. When users charge a portable electric device, they connect a transformer to the corresponding power source and the transformer alters the power to the standard DC voltage. An output port of the transformer connects with a first connection end of a power cord. A second connection end of the power cord connects with an input port of a converter. An output port of the converter connects to a charging port of a portable electric device. A power source is transformed into the standard DC voltage by the transformer, output via the standard output port of the transformer, transmitted via the power cord to the standard input port of the converter. The converter alters the standard DC voltage into a specially designed working voltage that is outputted via the output port of the converter to the charging port the portable electric device. Finally, the portable electric device is charged.  
         [0025]    Please refer to FIG. 3 (and FIG. 2). FIG. 3 is a state diagram of a combination of a power source, a transformer, a power cord, a converter, and a portable electric device according to the present invention. To charge the portable electric device  10 B, connect the power cord  40  to the output port  34 B of the transformer  32 B and to the input port  46 B of the converter  42 B. Now connect the output port  48 B of the converter  42 B to the input port  50 B of the portable electric device  10 B. Lastly, connect the input port  36 B of the transformer  32 B to an AC power source  20 . The transformer changes the AC power  20  into the standard DC voltage and the converter  42 B transforms the standard DC voltage into a specially designed working voltage that charges the portable electric device  10 B via the charging port  50 B.  
         [0026]    The most important characteristic of the present invention is using a separate power cord to connect the standardized output port of a transformer with the standardized input port of a converter. Thus, there is no need to provide a specially designed transformer for each portable electric device. For example, users can charge the portable electric device  10 A with the AC power  20  via the output port  48 A of the converter  42 A by connecting the power cord  40  between the transformer  32 B and the converter  42 A. The second connection end  43  of the power cord  40  can connect selectively the converter  42 A or  42 B to charge the portable electric device  10 A or  10 B because of the standardized input ports  46 A and  46 B of the converters  42 A and  42 B. Additionally, the portable electric device according to the present invention need not provide any specially designed transformers for different input power sources. For example, users can charge the portable electric device  10 B with the DC power  22  via the output port  48 B of the converter  42 B by connecting the power cord  40  between the transformer  32 C and the converter  42 B.  
         [0027]    Because standardized connectors are used, the power cord  40  can selectively connect to the transformers  32 A,  32 B, and  32 C. Therefore, various power sources, such as the battery  35 , the AC power  20 , or the DC power  22  can be used as long as the second end  43  of the power cord  40  connects to the input port  46 B of the converter  42 B. It is worthwhile to mention that many portable electric devices comprise a built-in USB standard charging port. The transformers and the corresponding power cords according to the present invention can be designed to the USB standard. Thus, each transformer can transform different power sources to a USB standard voltage and directly charge a portable electric device comprising a USB charging port.  
         [0028]    According to the present invention, each portable electric device is equipped with only one corresponding converter. Each power source used requires only one transformer. Users can charge different portable electric devices with different kinds of power sources via a power cord using the standard output port of a transformer and the standard input port of a converter. Therefore, users do not need to carry every charging system with them. The weight and volume of the converter according to the present invention is very small because the converter only transforms a standard DC voltage into another DC voltage. Additionally, the hard, cubic construction of transformers according to the present invention provides for easier carrying and the short power cord makes for easier storage.  
         [0029]    In contrast to the prior art, the present invention provides a single power charging system to charge multiple portable electric devices, eliminating the need for complete specially designed charging systems for each portable electric device and for each different kind of power source.  
         [0030]    Following the detailed description of the present invention above, those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.