Patent Publication Number: US-2009221170-A1

Title: Adaptive Plug With Discriminating Functionality

Description:
FIELD OF THE INVENTION 
     The present invention relates to wireless communication, and more particularly to charging interfaces for mobile terminals. 
     BACKGROUND OF THE INVENTION 
     It is known that a rechargeable device can be recharged by a relatively high current in order to be recharged faster. However, it is important that a charger providing a high current not be used with a rechargeable device that cannot accept that high current. Permanent damage to a wireless terminal (e.g. a mobile phone) can be caused by attempting to charge the terminal with a current that exceeds specifications. 
     Normal wireless phones cannot support high-current charging as such. Reasons for this include the cost and size of electronics needed to support a charging current exceeding one ampere, and also heating problems in small-sized terminals. However, high-current terminals are feasible. 
     One solution to avoid the over-charging problem would be if the high-current phones are recharged using chargers that cannot be used with normal phones, and if the normal phones are recharged using chargers that cannot be used with the high-current phones. However, this is an expensive solution that would require an entirely separate charging system for the two different types of phones. It would be very preferable if recharging systems would be sufficiently agile so that different recharging equipment would not always be needed for the two types of terminals. 
     It is not only desirable that a high-current phone can be charged with a standard charger, but also that the reverse can be done, without damaging either of the phones. High-current chargers are very useful for reducing charging delays, but on the other hand normal terminals cannot handle current in excess of one ampere. A mechanism to prevent accidental charging of a normal phone with a high current charger must be developed. 
     Also, from a manufacturing point of view, it would be better to not produce a different diameter plug interface for different charging interface versions, or to make different shapes for the plug. If parts are similar, then manufacturing costs will be less. 
     In the future, mobile terminal manufacturers will market mobile terminals that charge at different rates. It is essential that high-current chargers cannot be accidentally used with “normal phones.” Normal phones must not accept high-current chargers. This can be accomplished many ways. The software in a normal phone could be designed to reject the high-current chargers, but this would not be very convenient for the consumer, as the plugs would look the same. Nevertheless, making completely different interfaces for high-current chargers is not desirable, because it would be desirable good if normal chargers could be used for charging the high-current supporting phones also. 
     SUMMARY OF THE INVENTION 
     The present invention ensures that a normal charger can be used with either a normal terminal or with a high current terminal, while also ensuring that the high current charger cannot provide a high current to the normal terminal. Furthermore, it is also possible for a single plug to function as both a high current charger and as a normal charger. 
     It is possible to employ a fully mechanical approach in order to ensure that a normal charger can be used with either a normal terminal or with a high current terminal, while also ensuring that the high current charger cannot provide a high current to the normal terminal. This is done by implementing a longer plug for high-current chargers. Using the high-current charger in a normal phone is mechanically prevented. The high-current plug does not make contact with the standard jack. However, the standard plug operates correctly with the high-current jack. 
     Moreover, it is also possible for a high-current charger to be used in a normal charging mode with normal phones, by employing a dual ground implementation of the recharging plug. It may also be remarked that the functionality of the fully mechanical implementation can be combined with that of the dual ground implementation. It is possible to implement three versions of chargers that would be compatible with high-current-supporting phones: a high-current only-charger, a dual-mode charger (supporting both high-current and standard charging), and a standard charger. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a normal charging arrangement alongside a high current charging arrangement according to an embodiment of the present invention. 
         FIG. 2  shows a high current plug being used with a normal terminal and vice versa, according to an embodiment of the present invention. 
         FIG. 3  shows a plug capable of operating as a high current plug or a low current plug, according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention describes a system for recharging a mobile terminal using a higher-than-normal current, or using a normal current, the mobile terminal being either able or unable to accommodate the higher-than-normal current. The invention can be further appreciated by reference to the embodiments shown in the accompanying figures. 
     As seen in  FIG. 1 , a normal charger  105  is connected by wire  110  to a normal charging plug  115 . The plug  115  includes a plug element  120  as well as a portion  125  that extends beyond the plug element. 
     The high-current charger  130  has a similar arrangement, including a wire  135  connecting to a high-current plug  140  that has a high-current plug element  145  and a portion  150  that extends beyond the high-current plug element. Notice that the dimensions of these two plugs are somewhat different, as shown in  FIG. 1 . 
     The normal charging plug  115  plugs into a jack  155  of a normal terminal  160 , the normal jack  155  including a jack element  165  that comes into contact with the plug element  120  at which point the current flows from the normal charger to the normal terminal. 
     Likewise, the high-current charging plug  140  plugs into a jack  170  of a high-current terminal  175 , the jack  170  including a jack element  180  that comes into contact with the plug element  145  at which point the current flows from the high-current charger to the high-current terminal. Notice that the dimensions of these two jacks are somewhat different, as shown in  FIG. 1 . 
       FIG. 2  shows what happens if the plugs and jacks are crossed; i.e. if the high-current plug  140  is inserted into the normal jack  155 , and the normal plug  115  is inserted into the high-current jack  170 . The high current is not able to flow into the normal terminal  160 , but the normal current does flow into the high-current terminal  175 . Thus, the present invention allows the normal charger  105  to be safely used to charge up either type of terminal, whereas the high current charger  130  is carefully barred from overcharging the normal terminal  160  because the plug element  145  does not reach the jack element  165 . 
     Turning now to  FIG. 3 , this shows an additional embodiment of the present invention, where the plug  310  includes a high-current plug element  315  and a portion  320  that extends beyond the plug element. Unlike the high-current plug  140  in  FIG. 2 , the plug  310  in  FIG. 3  can be used to supply current to not just the high-current jack element  325 , but also to the normal jack element  330 . Likewise, the normal plug  335  can also be used to supply current to either jack. The plug  310  is able to provide two different levels of current, depending upon whether the jack element only reaches the portion  320  where the low current is available, or instead reaches all the way to the plug element  315  where the high current is available. 
     If a person uses the plug  310  to charge the jack element  325 , then the user may twist the plug to a position where it can be fully inserted onto the jack element  325 , and the pieces  340  and  345  show how the jack and the plug can be aligned. In contrast, the normal plug and jack do not have any pieces  350 ,  355  with these aligning characteristics. Regarding  FIG. 3 , both jacks are compatible with both plugs, although this is not the case for the embodiment shown in  FIG. 1  and  FIG. 2 . 
     It is to be understood that all of the present figures, and the accompanying narrative discussions of best mode embodiments, do not purport to be completely rigorous treatments of the method, terminal, and system under consideration. A person skilled in the art will understand that the steps and signals of the present application represent general cause-and-effect relationships that do not exclude intermediate interactions of various types, and will further understand that the various steps and structures described in this application can be implemented by a variety of different combinations of hardware and software which need not be further detailed herein.