Abstract:
A charging system for charging multiple portable devices includes transformers, branch converters and converters. Each transformer is specific to a different power supply. The branch converters and converters, specific to different portable devices, can be connected in such a way to transfer power to the various portable devices. Connections are standardized within the system giving it a modular design.

Description:
BACKGROUND OF INVENTION 
     1. Field of the Invention 
     The present invention relates to a charging system, and more particularly, to a charging system that can simultaneously charge multiple portable devices. 
     2. Description of the Prior Art 
     In this modern information based society, portable devices such as mobile phones, PDAs (Personal Data Assistants), CD players, portable video players (such as Digital Versatile Disc Players), hand-held computers, and notebook computers, are very common. As portable devices are becoming smaller and lighter, users are often found carrying around two or more. 
     In order to for these devices to function as portable, they require batteries, and typically, these batteries are rechargeable. Please refer to FIG.  1 . FIG. 1 is a perspective view showing a system by which portable devices are charged according to the prior art. The portable device  10 A has a charging port  12 A for receiving an operating voltage carried by direct current. Two kinds of transformers, used to charge the portable device  10 A, are shown. Transformer  16 A has an input port  17 A for receiving an alternating current  20  from a wall outlet. The transformer  16 A transforms the alternating current  20  into the operating voltage of the portable device  10 A and then outputs the operating voltage from an output port  14 A. Similarly, an input port  19 A of the transformer  18 A can receive a direct current  21  from a source such as a standard automobile power point. The transformer  18 A transforms the direct current into the operating voltage of the portable device  10 A and then outputs the operating voltage from an output port  15 A. Users can select either transformer  16 A or  18 A depending on the desired application. The output port of he transformer is connected to the charging port  12 A of the portable device  10 A and the portable device  10 A becomes charged. 
     Portable devices have various charging port connection standards and operating voltages. Common operating voltages are 3 and 12 volts and many devices have unique charging ports. Therefore, prior art devices require specific and often unique charging assemblies. As shown in FIG. 1 each of the three portable devices ( 10 A,  10 B, and  10 C) requires two charging assemblies each with a different transformer and connection. A user wanting to fully use the portability of these devices would have to carry around a total of six chargers ( 16 A,  18 A,  16 B,  18 B,  16 C, and  18 C). 
     As portable devices become increasingly popular, there are an ever-increasing number of places in which they can be charged. For example, automobiles provide direct current through a power point or cigarette lighter and some passenger planes provide charging sockets so that passengers can charge their portable devices while traveling. However, the prior art requires that users carry around exclusive transformers for each of the various portable devices. Not only is this an inconvenience to the user, having device specific chargers increases the costs of design and manufacture. Additionally, many of the places where a user can charge their portable devices only provide a single charging port. If a passenger of a car or airplane has more than one device that they wish to charge they must manually swap them a further inconvenience. 
     SUMMARY OF INVENTION 
     It is therefore a primary objective of the claimed invention to provide a charging system for portable devices that has a detachable modular design and utilizes a single power source to charge multiple portable devices requiring different operating voltages and having different connection standards. 
     The claimed invention, briefly summarized, discloses a charging system for charging a plurality of portable devices. Each portable device comprises a charging port for receiving a corresponding operating voltage of the portable device. The charging system comprises a plurality of transformers, at least a branch converter, and a plurality of converters. Each transformer is used to transform an input voltage into a standard voltage and output direct current from an output port. Each branch converter comprises an input port, a power conversion circuit, a transmission port, and an output port. The input port is used to receive the standard voltage outputted from the output port of the transformer. The power conversion circuit is used to transform the standard voltage into a transmission voltage and the corresponding operating voltage of the portable device. Each of the transmission voltage and the operating voltage are carried by direct current. The transmission port is used to output the transmission voltage. The output port corresponding to the charging port of the portable device is used to output the operating voltage of the portable device. The plurality of converters is used to transform the transmission voltage into a plurality of operating voltages required by the portable devices. Each converter comprises an input port corresponding to the transmission port of the branch converter for receiving the transmission voltage and an output port corresponding to the charging port of the portable device for outputting the operating voltage. When two portable devices need to be charged simultaneously, users connect the branch converter belonging to one of the portable devices to the transformer, and connect the converter belonging to another portable device to the branch converter. 
     It is an advantage that the claimed invention can charge many portable devices at once by using a single transformer and power supply. The claimed invention also has a modular design that can decrease production costs and makes it convenient and portable to the user. 
     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 
     FIG. 1 is a perspective view in which portable devices are charged according to the prior art. 
     FIG. 2 is a perspective view of an embodiment of a present invention charging system. 
     FIG. 3 is a functional block diagram in which a branch converter shown in FIG. 2 uses an alternating current power source to simultaneously charge two portable devices. 
     FIG. 4 is a perspective view of a second embodiment of the present invention charging system. 
     FIG. 5 is a functional block diagram of the second embodiment of the present invention charging system. 
    
    
     DETAILED DESCRIPTION 
     Please refer to FIG.  2 . FIG. 2 is a perspective view of an embodiment of a present invention charging system  22 . The present invention charging system can charge a plurality of portable devices. The embodiment shown in FIG. 2 uses four portable devices as an example. This, of course is not limiting. The present invention charging system can be widely used with various different portable devices. The portable devices  10 A,  108 ,  10 C and  10 D shown in FIG. 2 can be mobile phones, personal digital assistants, or notebook computers, among others. As mentioned above, each portable device  10 A to  10 D respectively has an exclusive charging port  12 A to  12 D. Each portable device must be supplied a specific operating voltage to charge safely and correctly. 
     The present invention charging system comprises a plurality of transformers, and of branch converters and converters corresponding to different portable devices. Each transformer corresponds to one kind of power source for transforming the power into a standard voltage carried by a direct current. As shown in FIG. 2, a transformer  16 D is designed for use with an alternating current power source  20  such as power provided by a wall socket. The transformer  16 D receives power from the alternating current power source  20  through an input port  17 D and transforms it into a standard voltage carried by direct current. The transformer  16 D outputs the standard voltage from an output port  14 D. Likewise, the transformer  18 D receives power from a direct current power source  21 , such as provided by a charging socket in an automobile or airplane, from an input port  19 D. The transformer  18 D transforms the power into a standard voltage carried by direct current, and then outputs the standard voltage from an output port  15 D. In the present invention, the physical connections of the output ports of each transformer are identical, and the output power has the same standard voltage. 
     The branch converters receive the standard voltage from a transformer and convert it to an operating voltage corresponding to a portable device, and a transmission voltage. Each branch converter has an output port and a transmission port. The output port is used to output the operating voltage corresponding to the portable device. The transmission port is used to output a transmission voltage carried by direct current. Branch converter  30 C, shown in FIG. 2, is designed for portable device  10 C. The input port  32 C of the branch converter  30 C can connect with the output port of each of the transformers  16 D and  18 D to receive the standard voltage. After receiving the standard voltage, the branch converter  30 C converts the standard voltage into the operating voltage of the portable device  10 C and the transmission voltage. The operating voltage of the portable device  10 C is outputted from the output port  34 C, and the transmission voltage is outputted from the transmission port  36 C. The physical connection of the output port  34 C matches that of the charging port  12 C of the portable device  10 C. The power outputted from the output port  34 C is that required by the portable device  10 C. Similarly, the branch converter  30 D is designed for the portable device  10 D. After receiving the standard voltage at the input port  32 D, the branch converter  30 D outputs the operating voltage of the portable device  10 D through an output port  34 D.The physical connection of the output port  34 D matches that of a charging port  12 D of the portable device  10 D. The branch converter  30 D further converts the standard voltage into the transmission voltage. The transmission voltage is outputted from a transmission port  36 D of the branch converter  30 D. In the present invention, the shape of the output port of each branch converter corresponds to a portable device (such as a notebook computer as illustrated). The branch converter transmission ports, however, have identical physical connections and transmission voltages. 
     Each of the plurality of converters of the present invention corresponds to a portable device. Each converter can accept the transmission voltage via an input port. The converter converts the transmission voltage into the operating voltage corresponding to a portable device, and then outputs the operating voltage through an output port. The output port of each converter can connect with the charging port of the corresponding portable device. The converter  42 A, shown in FIG. 2, can connect with the portable device  10 A. The converter  42 A converts the transmission voltage received at the input port  46 A into the operating voltage of the portable device  10 A, and then outputs the operating voltage through the output port  48 A. The physical connection of the output port  48 A matches that of the charging port  12 A of the portable device  10 A. Similarly, the converter  42 B is designed for the portable device  10 B and converts the transmission voltage received at the input port  46 B into the operating voltage of the portable device  10 B, and outputs the operating voltage from the output port  48 B. The physical connection of the output port  48 B matches that of the charging port  12 B. The connection of the input port of each converter mates with the transmission port of each branch converter. The input port of each converter can accept the transmission voltage outputted from the transmission port of each branch converter. 
     In the present invention, although each transformer is designed for different power sources, it is standardized in output port connection and power supplied. Each branch converter is designed for a different portable device. Although the output port of each branch converter is specific to a corresponding portable device, the input port of the branch converter can connect with the output port of each of the transformers. The connection and power output of the transmission port of each branch converter are also the same. Each converter is designed for a different portable device. The input ports of the converters are the same, in connection and power, and match the transmission port of the branch converters. 
     The operation of the present invention is illustrated as follows. For example, users want to use the direct current power source  21  to charge the portable device  10 C. Users can do that by first connecting the output port  15 D of the transformer  18 D to the input port  32 C of the branch converter  30 C, then connecting the output port  34 C of the branch converter  30 C to the corresponding charging port  12 C. The transformer  18 D transforms the power supplied by the direct current power source  21  into the standard voltage, also carried by direct current. The branch converter  30 C converts the standard voltage into the operating voltage of the portable device  10 C. The converted operating voltage is transmitted into the portable device, which becomes charged. If users now want to charge the portable device  10 B at the same time, users can do that by first connecting the transmission port  36 C of the branch converter  30 C to the input port  46 B of the converter  42 B, then connecting the output port  48 B of the converter  42 B to the charging port  12 B of the portable device  10 B. The branch converter  30 C not only converts the standard voltage into the operating voltage to charge the portable device  10 C, but also convert the standard voltage into the transmission voltage and transmits the transmission voltage to the converter  42 B through the transmission port  36 C. The converter  42 B converts the transmission voltage into the operating voltage of the portable device  10 B. The converted operating voltage is transmitted to the portable device  10 B through the output port  48 B and the charging port  12 B so that the portable device  10 B becomes charged. 
     One of the features of the present invention is that the output port of both transformers and the input port of each of the branch converters share the same connection standard. The transmission port of each branch converter and the input port of each converter also share a common connection standard. This allows many portable devices to be charged by the same transformer, although each portable device has a different operating voltage. Users can use various power sources to charge their portable devices and each portable device only needs one corresponding converter or branch converter. Therefore, each portable device need not have an exclusive transformer, as was the case of the prior art. 
     Additionally, the present invention can simultaneously charge two portable devices. For example, users can simultaneously charge the portable device  10 B while charging the portable device  10 C. To do this users only need to connect transmission port  36 C of the branch converter  30 C to the converter  42 B so that the portable device  10 B can be charged through output port  48 B and charging port  12 B. If users want to charge the portable device  10 A instead of the portable device  10 B, users need not change the branch converter  30 C but only disconnect the converter  42 B and connect the converter  42 A. 
     Please refer to FIG.  3 . FIG. 3 is a functional block diagram in which the branch convert  30 C shown in FIG. 2 uses the alternating current power source  20  to simultaneously charge the portable devices  10 C and  108 . In this embodiment, the branch converter  30 C has a power conversion circuit  41  for transforming the electrical power. The power conversion circuit  41  comprises a first transformation circuit  40 A and a second transformation circuit  40 B. The first transformation circuit  40 A is connected between the input port  32 C and the output port  34 C of the branch converter  30 C , transforms the standard voltage into the operating voltage of the portable device  10 C, and outputs the operating voltage through the output port  34 C. The second transformation circuit  40 B is connected between the input port  32 C and the transmission port  36 C, transforms the standard voltage into the transmission voltage, and outputs the transmission voltage through the transmission port  36 C. The first transformation circuit  40 A and the second transformation circuit  40 B can be accomplished with DC-to-DC conversion choppers. 
     Please refer to FIG.  4 . FIG. 4 is a perspective view of a second embodiment of the present invention charging system. The branch converter  30 E of this second embodiment is constructed differently from the branch converters  30 C and  32 D shown in FIG. 2, but the function remains identical. The branch converter  30 E comprises a first portion  33 A and a second portion  33 B. The first portion  33 A and the second portion  33 B have power ports  50 A and  50 B respectively and are detachably connected by these power ports. The branch converter  30 E converts the standard voltage into the operating voltage of the portable devices and transmits the operating voltage as the transmission voltage. The input port  32 E of the branch converter  30 E is installed on the first portion  33 A. The input port  32 E has a connection that fits that of the output port of the transformers and accepts the standard voltage. The output port  34 E is installed on the first portion  33 A of the branch converter  30 E for outputting the operating voltage corresponding to the portable device  10 C. In embodiment shown in FIG. 4, the output port  34 E connects with the charging port  12 C of the portable device  10 C. The transmission port  36 E of the branch converter  30 E is installed on the second portion  33 B for transmitting the transmission voltage. The standard of the transmission port  36 E is the same as the standard of the transmission ports  36 C and  36 D of the branch converters  30 C and  30 D shown in FIG.  2 . The transmission port  36 E can connect with the input port of the present invention converters and can provide the transmission voltage to the converters. 
     Please refer to FIG.  5 . FIG. 5 is a functional block diagram of the second embodiment of the present invention charging system. The branch converter  30 E can output power from the output port  34 C and the transmission port  36 E to charge the two portable devices  10 C and  10 B. The key difference between the branch converter  30 E and the branch converter  30 C is where the transformation circuits are installed. The first transformation circuit  40 C, which transforms the standard voltage into the operating voltage of the portable device  10 C, is installed inside the first portion  33 A of the branch converter  30 E, while the second transformation circuit  40 D, which transforms the standard voltage into the transmission voltage, is installed inside the second portion  33 B. The standard voltage received by the input port  32 E of the branch converter  30 E is routed to the second transformation circuit  40 D through the detachable connection of the power ports  50 A and  50 B. The second transformation circuit  40 D transforms the standard voltage into the transmission voltage and outputs the transmission voltage to the converter through the transmission port  36 E. The first transformation circuit  40 C is be designed for different portable vices. As the transformation circuits  40 C and  40 D are physically separated, a further cost savings can be realized by the fact that the second portion  33 B is independent of the portable device charged. 
     In conclusion, the modular design and standardized power transformation of the present invention allow users to simultaneously charge two or more portable devices conveniently. In the prior art, each portable device requires an exclusive transformer for different power sources. In contrast, the present invention only has one transformer for each power source to charge multiple portable devices, which is more efficient. The modular design of the present invention reduces its production cost and makes it conveniently portable. 
     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.