Abstract:
A power line adapter and its controlling method to be operated in a power-saving mode are disclosed. The power line adapter includes a power-transmitting module for generating a DC supply voltage and a data-transmitting module for transmitting data. Furthermore, the data-transmitting module at least includes a power line communication circuit and an Ethernet physical layer transceiver. The controlling method comprises steps of: monitoring a link signal generated by the Ethernet physical layer transceiver when the power line adapter is operated in an active mode; and, disconnecting the DC supply voltage to the power line communication circuit and entering the power-saving mode if the link signal indicates a disconnection over a first time period.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a power line adapter, and more particularly to a power line adapter can be operated in a power-saving mode. 
       BACKGROUND OF THE INVENTION 
       [0002]    In the recent years, the personal computers (PC) and the networks have played essential roles in people&#39;s life, and now, we rely on computer networks to retrieve and share information. Today, individual computers can be connected to a power-line network, wherein the power-line network is constructed based on the electrical wires. Unfortunately, the magnitude of voltage in the electrical wires is much higher than the magnitude of voltage in signal itself; furthermore, the magnitude of noise in the electrical wires is also relatively high. However, the above problems can be solved by using the power-line adapter. 
         [0003]      FIG. 1  is a diagram showing a power-line network, which is constructed by the electrical wires and power sockets in a house. Generally, there are a lot of power sockets in each division of a house, and these power sockets are connected in parallel by electrical wires. Today, these power sockets and electrical wires not only serve to supply the AC voltage (for example 120V 60 Hz), these power sockets and electrical wires can also be the components of the power-line network in the house. As depicted in  FIG. 1 , the AC voltage is supplied to the desktop computer  100  when the power plug  105  of the desktop computer  100  is plugged in the first power socket  110 . Furthermore, the desktop computer  100  can be connected to the laptop computer  200  by using the electrical wires in the house if the network cable  115  of the desktop computer  100  is plugged in the first power line adapter  120  which is plugged in the second power socket  125 , and also the network cable  215  of the laptop computer  200  is plugged in the second power line adapter  220  which is plugged in the third power socket  225 . 
         [0004]      FIG. 2  is a block diagram showing the circuit configuration of a conventional power line adapter. The power line adapter  300  comprises a power plug  302 , a power line communication circuit  304 , an Ethernet physical layer transceiver  316 , a network socket  318 , a bridge rectifier  320 , a power transformer  322 , and a DC/DC converter  324 . The power line communication circuit  304  further comprises a coupling unit  306 , a line driver  308 , an analog front-end circuit  310 , and a main controller  312 . 
         [0005]    In the conventional power line adapter  300 , the power plug  302 , the power line communication circuit  304 , the Ethernet physical layer transceiver  316 , and the network socket  318  together function as a data-transmitting module; the power plug  302 , the bridge rectifier  320 , the power transformer  322 , and the DC/DC converter  324  together function as a power-transmitting module which is for providing the DC supply voltage (Vcc) needed by the operations of the power line communication circuit  304  and the Ethernet physical layer transceiver  316 . That is, the AC voltage received by the power plug  302  is first converted to a first DC voltage by the bridge rectifier  320 ; the voltage level of the first DC voltage is further modulated by the power transformer  322 ; the modulated first DC voltage is further converted to the DC supply voltage (Vcc) by the DC/DC converter  324  and finally outputted to the power line communication circuit  304  and the Ethernet physical layer transceiver  316 . 
         [0006]    The network socket  318  is for the connection of the network cable (i.e., RJ45, not shown in  FIG. 2 ) of a computer, and data can be derived to or derived from the computer through the Ethernet physical layer transceiver  316 . In other words, when the computer is sending data out, the data outputted by the Ethernet physical layer transceiver  316  has to be processed and modulated by the main controller  312 , the analog front-end circuit  310 , the line driver  308 , and the coupling unit  306 , and then eventually transmitted to the electrical wires. Alternatively, when the computer is receiving data, the modulated data in the electrical wires is processed and demodulated by the coupling unit  306 , the analog front-end circuit  310 , and then eventually transmitted to the computer through the Ethernet physical layer transceiver  316 . 
         [0007]    Generally, the power line adapter is always plugged in the power socket, and accordingly the power is always consuming all the time even no cable connection is built or no data is transmitting between two computers. That is, 80%˜90% power, compared to the power consumed by the power line adapter operating in transmitting data, is waste. Therefore, designing a power line adapter capable of operated in a power-saving mode when no cable connection is built or no data is transmitting is the main purpose of the present invention. 
       SUMMARY OF THE INVENTION 
       [0008]    The object of the present invention is to provide a power line adapter capable of operated in a power-saving mode when no data is transmitting. 
         [0009]    The present invention provides a power line adapter, comprising: a power plug, which can be plugged in a power socket, for receiving an AC voltage; a power-transmitting module, connected to the power plug, for converting the AC voltage to a DC supply voltage; a data-transmitting module, connected to the power plug, for transmitting data to the power plug or receiving data from the power plug, wherein the data-transmitting module at least comprises a power line communication circuit and an Ethernet physical layer transceiver; a micro controller, connected to the Ethernet physical layer transceiver, for receiving a link signal and a package signal which are derived from the Ethernet physical layer transceiver, and generating a control signal in response to the link signal or the package signal; and, a switch circuit for receiving the control signal and the DC supply voltage; wherein the switch circuit connects the DC supply voltage to the power line communication circuit when the control signal makes the switch circuit in a close position, and the switch circuit does not connects the DC supply voltage to the power line communication circuit when the control signal makes the switch circuit in an open position. 
         [0010]    The present invention provides a method of controlling a power line adapter to be operated in a power-saving mode, wherein the power line adapter includes a power-transmitting module for generating a DC supply voltage and a data-transmitting module for transmitting data, and the data-transmitting module at least includes a power line communication circuit and an Ethernet physical layer transceiver, the method comprising steps of: monitoring a link signal generated by the Ethernet physical layer transceiver when the power line adapter is operated in an active mode; and, disconnecting the DC supply voltage to the power line communication circuit and entering the power-saving mode if the link signal indicates a disconnection over a first time period. 
         [0011]    The present invention provides a method of controlling a power line adapter to be operated in a power-saving mode, wherein the power line adapter includes a power-transmitting module for generating a DC supply voltage and a data transmitting-module for transmitting data, and the data-transmitting module at least includes a power line communication circuit and an Ethernet physical layer transceiver, the method comprises steps of: monitoring a link signal and a package signal generated by the Ethernet physical layer transceiver when the power line adapter is operated in an active mode; and disconnecting the DC supply voltage to the power line communication circuit and entering the power-saving mode if the link signal indicates a connection state and the package signal indicates no data being transmitting over a second time period. 
         [0012]    The above contents of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which: 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a diagram showing a power-line network. 
           [0014]      FIG. 2  is a block diagram showing the circuit configuration of a conventional power line adapter. 
           [0015]      FIG. 3  is a block diagram showing the circuit configuration of a power line adapter of the present invention. 
           [0016]      FIG. 4  is a table showing the power consumption of the power line adapter operated in both the active mode and the power-saving mode. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0017]    The main function of the power line adapter is to transmit the data between the electrical wires and the Ethernet, where the Ethernet mainly adopts the 100 Base-T, or the 10 Base-T protocol. The 100/10 Base-T protocol uses the peer-to-peer system for transmitting data, that is, one peer (i.e., desktop computer) is capable of realizing that the opposite peer (i.e., laptop computer) is connected or disconnected through a link signal (Link); furthermore, the data is transmitting between the two peers (desktop computer and laptop computer) or not can be also aware of according to a package signal (Rxdv). The above-mentioned characteristics in the peer-to-peer system are adopted for the implement of the power line adapter having a power-saving mode of the present invention. 
         [0018]      FIG. 3  is a block diagram showing the circuit configuration of a power line adapter of the present invention. The power line adapter  500  comprises: a power plug  502 , a power line communication circuit  504 , an Ethernet physical layer transceiver  516 , a network socket  518 , a bridge rectifier  520 , a power transformer  522 , a DC/DC converter  524 , a switch circuit  526 , and a micro controller  528 . The power line communication circuit  504  further comprises: a coupling unit  506 , a line driver  508 , an analog front-end circuit  510 , and a main controller  512 . 
         [0019]    In the power line adapter  500 , the power plug  502 , the power line communication circuit  504 , the Ethernet physical layer transceiver  516 , and the network socket  518  together function as a data-transmitting module; the power plug  502 , the bridge rectifier  520 , the power transformer  522 , and the DC/DC converter  524  together function as a power-transmitting module which is to provide the DC supply voltage (Vcc) needed by the operation of the power line communication circuit  504 , the Ethernet physical layer transceiver  516 , and the micro controller  528 . Additionally, the micro controller  528  and the switch circuit  526  together serve to provide a DC-controlled current path, and the switch circuit  526  can be implemented by a MOSFET. 
         [0020]    In the embodiment of the present invention, the DC supply voltage (Vcc) is always supplied to the Ethernet physical layer transceiver  516  and the micro controller  528  no matter the power line adapter  500  is operated in the active mode or in the power-saving mode. The micro controller  528  serves to generate a control signal (C) to the switch circuit  526  in response to the link signal (Link) or the package signal (Rxdv) that are derived from the Ethernet physical layer transceiver  516 . In other words, if the link signal (Link) indicates the connection is established and the package signal (Rxdv) indicates the data is transmitting, then the power line adapter  500  is assumed being operated in the active mode and the control signal (C) will make the switch circuit  526  in close position, accordingly the DC supply voltage (Vcc) is supplied to the coupling unit  506 , the line driver  508 , the analog front-end circuit  510 , and the main controller  512  of the power line communication circuit  504 . Alternatively, if the link signal (Link) indicates the connection is not established or the package signal (Rxdv) indicates the data is not transmitting, then the power line adapter  500  is assumed being operated in the power-saving mode and the control signal (C) will make the switch circuit  526  in open position, accordingly the DC supply voltage (Vcc) can not supply to the coupling unit  506 , the line driver  508 , the analog front-end circuit  510 , and the main controller  512  of the power line communication circuit  504 . 
         [0021]    In the embodiment of the present invention, when the power line adapter  500  is operated in the active mode, the occurrence of the disconnection (or no link) can be detected by the micro controller  528  according to the link signal (Link). That is, the occurrence of the disconnection can be realized by the micro controller  528  if user pulls out cable from the network socket  518  or a computer network socket. If the disconnection has been occurred over a first time period (i.e., 10 seconds), the micro controller  528  makes the switch circuit  526  in open position through the control signal (C). Accordingly the DC supply voltage (Vcc) cannot provide to the power line communication circuit  504 , and the power line adapter  500  enters the power-saving mode. When the micro controller  528  realizes the link (or connection) is rebuilt again through the link signal (Link), the micro controller  528  starts to make the switch circuit  526  in close position through the control signal (C). Accordingly the DC supply voltage (Vcc) is provided to the power line communication circuit  504 , and the power line adapter  500  enters the active mode again. 
         [0022]    In the embodiment of the present invention, the micro controller  528  starts to count time if the link signal (Link) indicates the link (or connection) is established but the package signal (Rxdv) indicates no data is transmitting when the power line adapter is operated in the active mode. If the power line adapter  500  is operated in the active mode but the status of no data transmitting has been occurred over a second time period (i.e., 10 minutes), the micro controller  528  then makes the switch circuit  526  in open position through the control signal (C). Accordingly the DC supply voltage (Vcc) cannot provide to the power line communication circuit  504 , and the power line adapter  500  enters the power-saving mode. When the power line adapter  500  is operated in the power-saving mode but the micro controller  528  realizes the data is transmitting again through the package signal (Rxdv), the micro controller  528  then makes the switch circuit  526  in close position through the control signal (C). Accordingly the DC supply voltage (Vcc) is provided to the power line communication circuit  504 , and the power line adapter  500  enters the active mode again. 
         [0023]      FIG. 4  is a table showing the power consumption of the power line adapter operated in both the active mode and the power-saving mode. The power consumption is 3.2 Watt when the power line adapter  500  is powered by an AC voltage (120V, 60 Hz) and operated in the active mode. The power consumption is down to 0.6 Watt when the power line adapter  500  is operated in the power-saving mode. Therefore, 80.83% power will be saved when the power line adapter  500  is operated in the power-saving mode due to the disconnection or no data transmitting. Similarly, the power consumption is 4.0 Watt when the power line adapter  500  is powered by an AC voltage (240V, 50 Hz) and operated in the active mode. The power consumption is down to 1.15 Watt when the power line adapter  500  is operated in the power-saving mode. Therefore, 71.25% power will be saved when the power line adapter  500  is operated in the power-saving mode due to the disconnection or no data transmitting. 
         [0024]    In the present invention, the switching between the active mode and the power-saving mode is achieved by detecting the link signal (Link) or the package signal (Rxdv) that are derived from the Ethernet physical layer transceiver  516 . The power consumption is significantly reduced when the power line adapter of the present invention is operated in the power-saving mode. 
         [0025]    While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.