Patent Publication Number: US-7722370-B2

Title: Socket with detection functions

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a socket with a detection function, and more particularly to a network socket that detects a type of an inserted plug according to voltage variation of a detection pin. 
   2. Description of the Prior Art 
   Currently, fool-proof designs of an RJ-45 network socket are still not good enough, so a phone cable plug of a type similar to a network cable plug, e.g. an RJ-11 plug, can be easily inserted into the network socket. However, since a great difference exists between signals carried on phone cables and network cables, when the phone cable plug is wrongly inserted into the network socket, not only may back-end electronic devices of the network socket be damaged, but the phone-line circuit loop may also enter a short-circuit state, causing the phone line to appear to be engaged. 
   For example, please refer to  FIG. 1 .  FIG. 1  is a schematic diagram of a circuit loop between a telephone set  11  and a branch exchange  12  in a conventional public switched telephone network (PSTN). When the telephone set  11  is not picked up, or on the hook, a hook switch  112  is in an open-circuit state. At this time, a DC operating voltage that the branch exchange  12  supplies to the telephone set  11 , i.e. a voltage between Tip  13  and Ring  14 , roughly lies between 36 and 60 volts depending on the country. When alerting an incoming call, an AC ring signal of about a hundred volts (40 to 150 Vpp) is superimposed over the DC operating voltage to ring the telephone set  11  by the branch exchange  12 . Therefore, when the phone cable plug is wrongly inserted into the network socket, the back-end electronic devices of the network socket, such as a notebook computer, may be damaged due to inability to bear such high voltages as the DC operating voltage and the AC ring signal. In addition, please refer to  FIG. 2 .  FIG. 2  is a schematic diagram of a pulse transformer  20  built in a conventional network socket. The pulse transformer  20  includes input terminals RX 0 + to RX 3 +, RX 0 − to RX 3 − and output terminals TX 0 + to TX 3 +, TX 0 − to TX 3 −, for receiving and outputting network signals, respectively, and is utilized for enhancing reception reliability of the network socket by filtering electromagnetic interference from the high frequency differential signals. As shown in  FIG. 2 , when the phone cable plug is wrongly inserted into the network socket, the Tip  23  and the Ring  24  are respectively coupled to the input terminals RX 2 + and RX 2 −, and since the input terminals RX 2 + and RX 2 − are short-circuited inside the pulse transformer  20 , the phone-line circuit loop is then operated in a state similar to an off-hook state of the hook switch  112  in  FIG. 1 , causing the phone line to seem to be engaged. 
   On the other hand, since the trend of the notebook computer is toward lightweight and small size development, less space is available at the periphery of the notebook computer for installing input/output ports, except for batteries, optical drives, and cooling fans, so if the phone cable sockets and the network cable sockets could be integrated, the space occupied by these sockets will be reduced effectively. 
   SUMMARY OF THE INVENTION 
   It is therefore an objective of the present invention to provide a socket with a detection function. 
   According to the present invention, a socket with a detection function is disclosed. The socket includes a plurality of metal spring pins, a first detection pin and a second detection pin. The first detection pin is formed on a side of the plurality of metal spring pins, and is coupled to a system ground. The second detection pin is formed on another side of the plurality of metal spring pins, and is coupled to a pull high resistor that provides a high voltage level for the second detection pin. The second detection pin further includes an elastic metal arm extending toward the first detection pin and forming on a top of the first detection pin. The first metal spring pin of the plurality of metal spring pins is pressed down to make the elastic metal arm of the second detection pin contact the first detection pin when a phone cable plug is inserted into the socket. 
   These and other objectives of the present 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 THE DRAWINGS 
       FIG. 1  is a schematic diagram of a circuit loop between a telephone set and a branch exchange in a conventional PSTN. 
       FIG. 2  is a schematic diagram of a pulse transformer built in a conventional network socket. 
       FIG. 3  is a rear-view diagram of a socket with a detection function according to an embodiment of the present invention. 
       FIG. 4  merely shows the metal spring pins and the detection pins in  FIG. 3 . 
       FIG. 5  and  FIG. 6  are schematic diagrams of a socket when a network cable plug and a phone cable plug are inserted according to an embodiment of the present invention, respectively. 
   

   DETAILED DESCRIPTION 
   Please refer to  FIG. 3 .  FIG. 3  is a rear-view diagram of a socket  30  with a detection function according to an embodiment of the present invention. The socket  30  includes a housing  31 , metal spring pins Pin 1  to Pin 8 , and detection pins PinA and PinB. The metal spring pins Pin 1  to Pin 8  are placed in parallel inside the housing  31 , and are individually utilized for receiving signals. The detection pin PinA is formed on a side of the metal spring pins Pin 1  to Pin 8 , and is coupled to a system ground GND. The detection pin PinB is formed on another side of the metal spring pins Pin 1  to Pin 8 , and is coupled to a pull-up resistor R 1  that provides a high voltage level for the detection pin PinB. The detection pin PinB further includes an elastic metal arm  32  extending toward the detection pin PinA and formed on a top of the detection pin PinA. Preferably, the socket  30  is a RJ-45 network socket, and a most lateral metal spring pin of the metal spring pins Pin 1  to Pin 8 , e.g. Pin 1 , further includes an extension part  33  bended inward and downward to the socket  30 . 
   For simple illustration, please further refer to  FIG. 4 , which merely shows the metal spring pins Pin 1  to Pin 8  and the detection pins PinA and PinB in  FIG. 3 . The metal spring pins Pin 1  to Pin 8  are normal pins of an RJ-45 network socket, and thus when an RJ-45 network cable plug is inserted into the socket  30 , network signals can be received by the metal spring pins Pin 1  to Pin 8 , respectively. Such reception operations are well-known by those skilled in the art, and are not narrated herein. Compared with the RJ-45 plug (network cable plug), a RJ-11 plug (phone cable plug) merely has six pins, but spacing between each pin of the phone cable plug is similar to that of the RJ-45 plug. Thus, when an RJ-11 plug (phone cable plug) is inserted into the socket  30 , the metal spring pins Pin 1  and Pin 8  located on each side of the socket  30  are both pressed down by a housing of the phone cable plug. In such a situation, the elastic metal arm  32  of the detection pin PinB is forced to contact the detection pin PinA in the embodiment of the present invention, so that the type of the inserted plug can be determined according to the voltage variation of the detection pin PinB. 
   For example, please refer to  FIG. 5  and  FIG. 6 .  FIG. 5  and  FIG. 6  are schematic diagrams of the socket  30  when a network cable plug and a phone cable plug are inserted according to an embodiment of the present invention, respectively. As shown in  FIG. 5 , when an RJ-45 plug or no plug is inserted into the socket  30 , since the detection pin PinB is not contacted by the detection pin PinA, a voltage level of the detection pin PinB is still kept at a high voltage level provided by the pull-up resistor R 1 . On the other hand, as shown in  FIG. 6 , when an RJ-11 plug is inserted into the socket  30 , the metal spring pins Pin 1  and Pin 8  on each side of the socket  30  are both pressed to the bottom by the housing of the phone cable plug, causing the elastic metal arm  32  of the detection pin PinB to contact the detection pin PinA, so as to change the voltage level of the detection pin PinB to that of the detection pin PinA, i.e. the voltage level of the system ground GND. 
   Therefore, the inserted plug type of the socket can be determined by the voltage variation of the detection pin PinB in the embodiment of the present invention, so as to switch signals received by the metal spring pins Pin 1  and Pin 8  to couple between a network signal processing module and a phone signal processing module. Moreover, the network sockets (RJ-45 sockets) and the phone sockets (RJ-11 sockets) can then be integrated for reducing the space required by the sockets. 
   Please note that the above embodiments are merely exemplary illustrations of the present invention, and that those skilled in the art can certainly make appropriate modifications according to practical demands, which also belong to the scope of the invention. For example, the detection pin PinA can further be realized by a metal housing of the socket  30 , thereby only one additional detection pin is required to achieve the same detection function in the embodiment of the present invention. Or, the metal spring pin Pin 8  can be used for replacing the metal spring pin Pin 1  to change the voltage level of the detection pin in another embodiment of the present invention. Such variations also belong to the scope of the present invention. 
   As mentioned above, the inserted plug type of the network socket can be determined by the voltage variation of the detection pin in the embodiment of the present invention, so as to control the back-end electronic devices to switch reception of the network signals and the phone-line signals. Therefore, the network cable sockets and the phone cable socket can then be integrated for reducing the required space effectively. 
   Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention.