JP2010034780A - Noise filter with balun transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a noise filter with a balun transformer, which can simply construct a system suited to in-phase communication and communication between different phases by using existing coaxial wires in a power line carrier communication for transmitting/receiving signals by superposing a high frequency signal to a power line. <P>SOLUTION: The noise filter 13 with the balun transformer, which is arranged between a PLC modem 3 connected to a power line and a PC 1 (11) in the power line carrier communication for transmitting/receiving signals by superposing the high frequency signal to the power line includes: a noise filter 4 whose input/output terminal is a balanced terminal; the balun transformer 15 which is a balance-unbalance conversion circuit connected in parallel with the noise filter 4; and a noise filter 4 whose input/output terminal is an unbalanced terminal; and a coaxial connector 7. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power line carrier communication wiring device that enables power supply and transmission / reception of data signals using an indoor power line used in ordinary houses and the like.

  FIG. 6 is a diagram schematically illustrating the configuration of the power line communication system disclosed in Patent Document 1. As shown in FIG. 6, a high-voltage distribution line (6600V) 22 is installed on the top of a utility pole (not shown), and a pole transformer 21 that reduces the voltage of the high-voltage distribution line 22 to a commercial voltage (100V) is a utility pole. It is installed at a high place. From the secondary side of the pole transformer 21, a low-voltage distribution line 23 and a neutral line 24 in the low-voltage distribution line 23 are drawn out and a customer distribution board (not shown) is connected via a watt-hour meter (not shown). Power distribution to The power line communication system includes a coupler 26 that couples a signal generated between one of the low-voltage distribution lines 23 and the neutral line 24 to a modem 25, a signal line 27 that connects the coupler 26 and the modem 25, and And a filter 28 attached to the ground wire 29.

  Electric power is drawn from the two lines of the high-voltage distribution line 22 and connected to the primary side of the pole transformer 21, and the midpoint of the secondary side is grounded by the ground line 29. The two wires on the secondary side are input to the coupler 26 and are connected to the coupling transformer 26a via the capacitor 26b constituting the coupler 26. Capacitor 26b is set to have a high impedance for commercial frequencies (50/60 Hz) and a low impedance for high frequencies. As a result, only the high-frequency signal passes through the coupling transformer 26a and the commercial frequency is blocked, so that the capacity of the transformer can be reduced. Accordingly, a high frequency signal is generated on the secondary side of the coupling transformer 26a and is input to the modem 25 through the signal line 27 of the twisted pair cable.

  In the present invention, the signal line 27 and the ground line 29 are connected in the high-frequency region by mounting the filter 28 together with the signal line 27 on the secondary side of the coupling transformer 26a and the ground line 29 for grounding the neutral line 24. By combining them to form a balanced circuit, different potential components from the ground at this frequency are attenuated by this filter 28, so that a high-frequency leakage electric field from the distribution line can be reduced. With this configuration, it is possible to supply data from a WAN (Wide Area Communication Network) composed of an optical fiber or the like to the user's home A via the filter 28, the coupler 26, and the low-voltage distribution line 23. The data can be received by the PC 31 after being demodulated by the modem (slave unit) 30. Data from the PC 31 is modulated by the modem (slave unit) 30 and transmitted to the WAN via the low-voltage distribution line 23, the coupler 26, the filter 28, and the modem 25. A plurality of user homes B are connected to the low voltage distribution line 23.

JP 2004-289458 A

  The spread of the Internet in recent years has been remarkable, and the importance of the access environment to the Internet is increasing even at home, and power line communication, that is, PLC (Power Line Communications), has attracted attention as means for simplifying the access. Since the line is connected by simply plugging it into the AC power line, which is an existing indoor wiring, a personal computer can be connected to the Internet without any new wiring work, and a home network for connecting electrical equipment can be easily constructed. Will be. PLC communication speeds of 2 to 30 MHz are permitted (October 4, 2006), and large-capacity information can be communicated. At present, a PLC device is connected mainly to an indoor power line, and then connected to a personal computer or the like for communication.

  The single-phase, three-wire 100V wiring used for indoor power lines in general households is composed of an L1 phase and an L2 phase, with the middle wire grounded. When communicating with a PLC (Power Line Communications) device, communication between different phases between the power line (outlet) connected to the L1 phase and the power line (outlet) connected to the L2 phase is the same phase communication In this case, it is difficult to obtain the maximum effective communication speed in the specifications, and in the case of using a distribution board of another system, depending on the situation Communication may not be possible.

  FIG. 4 shows an example of a configuration diagram of power line carrier communication in a general household. The single-phase three-wire system 100V is wired through the distribution board 1 of each home. For PLC communication between the same rooms, a signal from a WAN 10 (wide area communication network) such as the Internet passes through a BB circuit terminator 9 such as an ADSL modem and is superposed on a commercial frequency by a PLC modem 3 through a noise filter 4 and is connected to an outlet 2 It is conveyed to the indoor wiring L1 phase or L2 phase. PLC communication between the same rooms is in-phase communication. From the outlet 2, only the high frequency signal passes through the PLC modem 3 and the commercial frequency is blocked, and communicates with the PC 1 (11) through the noise filter 4. PLC communication between the same rooms can be performed without any problem in the L1 phase and the L1 phase (in-phase communication). However, in the case of different rooms, if the indoor power line is grounded in a different phase, communication may be difficult because the signal is significantly reduced between the L1 phase and the L2 phase (interphase communication).

  FIG. 5 is an example of a noise filter configuration diagram. The noise filter 4 is set so that the communication frequency band of the PLC modem passes but the power frequency band of home appliances cannot pass. Further, the normal noise filter 4 is inserted into the PLC modem and the balanced wiring inside the PC.

  In order to improve the communication situation as much as possible, the impedance upper 6 is connected to the indoor power line in power line carrier communication to improve the influence of the impedance from the home appliance (TV 8) on the outlet 2 and the home appliance (TV 8). Install between. By connecting a household electrical appliance with low impedance to the power line carrier communication system, a signal flows to a device with low impedance, but this can be handled by connecting an impedance upper in between.

  In FIG. 4, PLC communication can be easily performed in the same phase in the room 1, but communication between different phases such as the room 1 and the room 2 is difficult.

  Wireless LAN, wired LAN, etc. can be considered as countermeasures for inter-phase communication. However, in the case of wireless LAN, it is necessary to purchase and install a new device, and communication is performed if the wall contains reinforcing bars. It becomes difficult. Usually, there are many cases where PLC communication is considered because a wireless LAN cannot be used, and the reason is that communication becomes difficult if the wall contains the above reinforcing bars. In the case of a wired LAN, it is necessary to purchase and install a new device, and it is necessary to install a LAN cable.

  Therefore, an object of the present invention is to provide a function of a conventional noise filter that does not reduce a signal during phase-to-phase communication in power line carrier communication and that does not require a new device by using existing coaxial wiring. Another object of the present invention is to provide a noise filter with a balun transformer comprising a noise filter having an unbalanced terminal incorporating a balanced-unbalanced conversion circuit (balun transformer).

  As a countermeasure for the above-described inter-phase communication, it is conceivable to perform communication using the coaxial wiring 14 for TV signals or the like that is often installed between different rooms, but the coaxial wiring 14 is an unbalanced wiring. Therefore, communication is difficult only with the PLC communication device for balanced wiring and the conventional noise filter, and since the noise filter 4 does not have a coaxial connector, the coaxial wiring 14 such as an existing TV signal line is directly installed. Cannot connect to. As another device, since a device having a balun transformer is used for balanced-unbalanced conversion, the connection is complicated and the cost may increase. For that purpose, the interphase communication has been improved by using a coaxial cable (unbalanced wiring) and a balun transformer for the noise filter.

  A balun transformer is a signal conversion element using a balun circuit for mutually converting an unbalanced signal propagating through an unbalanced transmission line and a balanced signal propagating through the balanced transmission line.

  The noise filter is a filter composed of a coil element and a capacitor element.

  The present invention is power line carrier communication that transmits and receives signals by superimposing high-frequency signals on power lines, and performs communication using coaxial wiring for TV signals and the like that are often installed between different rooms. This is a noise filter with a balun transformer. The noise filter with a balun transformer is preferably configured by integrating a balanced-unbalanced conversion circuit (balun transformer) and a coaxial connector serving as an unbalanced terminal for connection to the coaxial wiring.

  According to the present invention, in power line carrier communication for transmitting and receiving a signal by superimposing a high frequency signal on a power line, a noise filter with a balun transformer installed between a modem connected to the power line and a PC, the input / output terminal A balun comprising: a noise filter having a balanced terminal; a balun transformer being a balanced-unbalanced conversion circuit in parallel with the noise filter; a noise filter having an input / output terminal as an unbalanced terminal; and an unbalanced terminal. A noise filter with a transformer is obtained.

  According to the present invention, a noise filter with a balun transformer is obtained in which a coaxial connector is connected to the external connection side of the unbalanced terminal.

  According to the present invention, it is possible to obtain a noise filter with a balun transformer, wherein the balun transformer includes a signal conversion element using a balun circuit.

  According to the present invention, it is possible to obtain a noise filter with a balun transformer, wherein the noise filter circuit includes a coil element and a capacitor element.

  With the above configuration, the noise filter with a balun transformer according to the present invention is provided with another noise filter, a balun transformer, and its output terminal in addition to the conventional noise filter circuit and its input / output terminal. A noise filter having a balanced conversion function and packaged with unbalanced terminals connectable to unbalanced wiring is obtained.

  The power line carrier communication has a characteristic that the signal is more easily attenuated during inter-phase communication than in the inter-phase communication, and it is difficult to obtain the maximum execution communication speed according to the specifications. In some cases, communication may not be possible depending on the situation. By using the noise filter with a balun transformer of the present invention, it is possible to perform carrier communication with little direct signal attenuation using coaxial wiring that is often installed between different rooms. Since the existing coaxial wiring for TV signals is used, it is not necessary to purchase and install a new cable, thereby preventing an increase in cost. In addition, since the noise filter is integrated with the balanced-unbalanced conversion function, the coaxial wiring and the coaxial connector, the size can be reduced.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a structural diagram of general household power line carrier communication according to the present invention. FIG. 2 is a configuration diagram of a noise filter with a balun transformer according to the present invention. 1-2, the housing and the output terminal are schematically shown.

  A noise filter 13 with a balun transformer having an unbalanced terminal of the present invention shown in FIG. 2 includes a coaxial connector 7 for connecting to a coaxial wiring 14, a noise filter 4 and a balun transformer 15, and a PLC from the coaxial connector 7 The signal of the communication frequency band of the modem 3 is passed. The noise filter 4 composed of a coil and a capacitor does not pass signals in the power supply frequency band of household appliances that are noise sources other than signals in the communication frequency band and signals in the low frequency band.

  The balun transformer 15 is a balun circuit including a coil and a capacitor for mutually converting an unbalanced signal propagating through the unbalanced transmission line and a balanced signal propagating through the balanced transmission line.

  The noise filter 4 includes a coil element and a capacitor element, and values of the coil element and the capacitor element are determined so as to pass a power line carrier signal of 2 MHz to 30 MHz.

  The case of the configuration diagram of general household power line carrier communication according to the present invention shown in FIG. 1 will be described. The single-phase three-wire system 100V is wired to each room through the distribution board 1 of each household. For PLC communication between the same rooms, a signal from a WAN 10 (wide area communication network) such as the Internet passes through a BB circuit terminator 9 such as an ADSL modem and is superposed on a commercial frequency by a PLC modem 3 through a noise filter 4 and is connected to an outlet 2 It is conveyed to the indoor wiring L1 phase or L2 phase. PLC communication between the same rooms is in-phase communication. From the outlet 2, only the high frequency signal passes through the PLC modem 3 and the commercial frequency is blocked, and communicates with the PC 1 (11) through the noise filter 13 with a balun transformer having an unbalanced terminal. PLC communication between the same rooms can be performed without any problem in the L1 phase and the L1 phase (in-phase communication).

  However, in the case of different rooms, if the indoor power line is grounded in a different phase, communication may be difficult because the signal is significantly reduced between the L1 phase and the L2 phase (interphase communication). Therefore, in order to improve the communication situation as much as possible, in order to improve the influence of the impedance from the home appliance (TV8) on the indoor power line in the power line carrier communication, the impedance between the outlet 2 and the home appliance (TV8) is improved. Upper 6 is installed. By connecting a household electrical appliance having a low impedance to the power line carrier communication system, a signal flows to a device having a low impedance. Therefore, it is possible to cope by connecting an impedance upper in between.

  However, although the PLC communication can be easily performed in the same phase in the room 1 only by installing the impedance upper 6, for example, communication between different phases such as the room 1 and the room 2 shown in FIG. It was often difficult. However, when the balun transformer-equipped noise filter 13 having an unbalanced terminal of the present invention is used, the coaxial connector 7 in the room 1 is connected from the coaxial connector 7 of the balun transformer-equipped noise filter 5 by the coaxial wiring 14 with a coaxial connector. Further, the coaxial connector 7 which is an unbalanced terminal in the room 1 is connected to the coaxial connector 7 which is an unbalanced terminal in the room 2 via the existing coaxial wiring 14, and is further balanced by the coaxial wiring 14 with the coaxial connector. By being connected to the coaxial connector 7 of the noise filter with transformer 5, signals can be transmitted and received with the PC 2 (12) in the room 2. In this case, the coaxial connector 7 of the noise filter 5 with balun transformer and the coaxial connector 7 of the coaxial wiring 14 may be directly connected without using the coaxial wiring 14 with the coaxial connector. The coaxial connector 7 of the noise filter 5 with balun transformer may be provided at the tip of a coaxial cable or the like drawn from the board or housing without being provided on the board or housing of the noise filter 5 with balun transformer.

  As described above, by replacing the noise filter with balun transformer of this embodiment with a conventional noise filter, communication is performed by superimposing unbalanced wiring between rooms where power lines are wired in different phases. be able to. Further, the wiring is not complicated as in the case of connecting another device to the conventional noise filter.

  FIG. 3 shows an example of a circuit of a noise filter with a balun transformer of the present invention. A noise filter 13 with a balun transformer having an unbalanced terminal of the present invention shown in FIG. 3 includes a coaxial connector 7 which is an unbalanced terminal for connection to the coaxial wiring 14, a noise filter 4 comprising a coil and a capacitor, and an LPF (low pass). And a balun transformer 15 constituting the filter.

  As described above, according to the present invention, a noise filter with a balun transformer that has a function of a conventional noise filter and is packaged so as to be directly connectable with an unbalanced wiring is obtained.

  Needless to say, the present invention is not limited to the above embodiment, and the housing, terminals, and shapes thereof used in the present invention, the balun transformer, the noise filter, and the like are arbitrarily designed according to the purpose. can do.

  As mentioned above, although embodiment of this invention was described, this invention is not restricted to these embodiment, Even if there is a design change of the range which does not deviate from the summary of this invention, it is included in this invention. That is, various changes and modifications that can be naturally made by those skilled in the art are also included in the present invention.

  By using the noise filter with a balun transformer of the present invention, a system suitable for in-phase communication and inter-phase communication using existing coaxial wiring in power line carrier communication for transmitting and receiving signals by superimposing high-frequency signals on power lines It can be constructed easily.

The block diagram of the general household power line carrier communication by this invention. The block diagram of the noise filter with a balun transformer by this invention. An example of the circuit of the noise filter with a balun transformer by this invention. An example of a lineblock diagram of general household power line carrier communications. An example of a noise filter block diagram. The figure which represented typically the structure of the power line communication system of patent document 1. FIG.

Explanation of symbols

1 Switchboard 2 Outlet 3 PLC Modem 4 Noise Filter 5 Noise Filter with Balun Transformer 6 Impedance Upper 7 Coaxial Connector (Unbalanced Terminal)
8 TV
9 BB circuit terminator (ADSL modem, etc.)
10 WAN (Wide Area Network)
11 PC1
12 PC2
13 Noise filter 14 with balun transformer having unbalanced terminal Coaxial wiring 15 Balun transformer 21 Column transformer 22 High voltage distribution line 23 Low voltage distribution line 24 Neutral line 25 Modem (master)
26 Coupler 26a Coupling transformer 26b Capacitor 27 Signal line 28 Filter 29 Ground line 30 Modem (slave unit)
31 PC

Claims (4)

  A noise filter with a balun transformer installed between a modem connected to the power line and a PC in power line carrier communication for transmitting and receiving signals by superimposing a high frequency signal on the power line, wherein the input / output terminal is a balanced terminal A noise filter with a balun transformer, comprising: a filter; a balun transformer that is a balanced-unbalanced conversion circuit in parallel with the noise filter; a noise filter having an input / output terminal as an unbalanced terminal; and an unbalanced terminal.   The noise filter with a balun transformer according to claim 1, wherein a coaxial connector is connected to an external connection side of the unbalanced terminal.   2. The noise filter with a balun transformer according to claim 1, wherein the balun transformer includes a signal conversion element using a balun circuit.   The noise filter with a balun transformer according to claim 1, wherein the filter circuit includes a coil element and a capacitor element.

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