JP2010124384A - Plc noise filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power line communication (PLC) noise filter which includes functions of conventional noise filters and incorporates a power line/telephone line conversion and power line/coaxial cable conversion functions. <P>SOLUTION: The PLC noise filter includes a first balanced circuit 6 disposed in the middle of a power line consisting of balanced wiring and a home electrical appliance connected to the power line, a second balanced circuit 7 connected in parallel to the first balanced circuit 6, and one unbalanced circuit 8. The first balanced circuit 6 includes a function of passing a power supply frequency band of the home electrical appliance of 50 Hz to 60 Hz and not passing a frequency band to be used for PLC. The second balanced circuit 7 and the unbalanced circuit 8 are connected in parallel to the first balanced circuit 6 via two DC cut capacitors 9 connected in series to two pieces of wiring. The second balanced circuit 7 is connected to a telephone line 14 consisting of balanced wiring via a telephone line modular jack 1 as a balanced terminal inverse to the power line. <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 a general house or the like.

  The spread of the Internet in recent years is remarkable, and the spread of high-speed access environment to the Internet is increasing by wiring optical fibers from the office building to the home. At present, attention is paid to power line communication, that is, PLC (Power Line Communication) as means for simplifying home network construction. Since the line is connected just by plugging into the AC power line power outlet that is the existing indoor wiring, the PC is connected to the Internet in any room in the home without any new wiring work, In addition, a home network for connecting electrical devices to each other can be easily constructed.

  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. In communication by PLC, a technique for removing noise from electrical devices in the home is indispensable. For example, in Patent Document 1, a different potential from the ground is attenuated to reduce leakage of an electric field from a distribution line. A technique for providing a power line communication system is disclosed.

  Patent Document 1 discloses the following configuration. Power is drawn from the two lines of the high-voltage distribution line and connected to the primary side of the pole transformer, and the midpoint of the secondary side is grounded by the ground line. The two wires on the secondary side are input to the coupler and connected to the coupling transformer via a capacitor constituting the coupler. The capacitor is set to have a high impedance with respect to the commercial frequency (50/60 Hz) and a low impedance with respect to the high frequency. Thereby, only the high frequency signal passes through the coupling transformer and the commercial frequency is blocked, so that the transformer capacity can be reduced. Therefore, a high-frequency signal is generated on the secondary side of the coupling transformer, and is input to the modem through a twisted pair cable.

JP 2004-289458 A

  The indoor power line of a general household is a single-phase three-wire 100V and the middle wire is grounded. When communicating with a PLC device, in the so-called inter-phase communication via different outlets connected to one of the grounded middle wire and the other two different wires that are not grounded, the phases that match the wires that are not grounded are the same. Compared with so-called in-phase communication, the signal is significantly reduced, and communication may not be possible between some outlets.

  FIG. 5 shows a configuration diagram in the case where a PLC communication device and a conventionally used noise filter 16 are connected to an indoor power line of a general home that is the basis of the present invention. PLC communication using the outlet 5 that is in the same phase in the same room can be communicated between L1 and GND (interphase communication) without any problem. However, in the case of the communication between the outlets 5 connected between L1 and GND and between the outlets 17 not connected in the same phase connected between L2 and GND (for example, between different rooms), that is, in the communication between the phases where the indoor power lines are grounded in different phases. As described above, since the signal is remarkably reduced, communication may be difficult.

  FIG. 4 shows a conventionally used noise filter composed of a coil and a capacitor as a basis of the present invention. This noise filter has an impedance upper function, is connected in parallel with the PLC modem 4, and is connected to the home appliance at a terminal opposite to the household outlet 5. This noise filter passes the power frequency band of household appliances of 50 Hz or 60 Hz, but cannot pass the communication frequency band of PLC (impedance upper function). Therefore, noise does not leak from the noise source 3 such as home appliances to the PLC modem 4.

  In the configuration of FIG. 5, PLC communication can be easily performed in the same phase, but communication is difficult between different phases as described above.

  Therefore, the present invention was made to solve the problem that it is difficult to realize communication between different phases in the home, and the purpose thereof is to have a function of a conventional noise filter, and An object of the present invention is to provide a noise filter for PLC further incorporating a power line-telephone line conversion function and a power line-coaxial cable conversion function. That is, an object of the present invention is to provide a PLC noise filter that can use a telephone line or a coaxial cable for television for PLC communication between different phases without requiring special equipment and new indoor wiring.

  The noise filter for PLC of the present invention has the function of an impedance upper as in the conventional noise filter, and improves the influence of the impedance of the home appliance on the indoor power line in PLC communication. If a household appliance with low impedance is connected to the PLC communication system, a PLC communication signal flows to the household appliance with low impedance unless a filter or the like is used. If the PLC noise filter of the present invention is connected, it is possible to cope with signal leakage to the home appliance side as in the conventional noise filter.

  In order to solve the above-described problems, the present invention is a PLC noise filter used for power line carrier communication (PLC communication), and is disposed between a power line formed of balanced wiring and a home appliance connected to the power line. It consists of a first balanced circuit and a second balanced circuit or / and one unbalanced circuit connected in parallel to the first balanced circuit, the first balanced circuit being a low pass filter, 50 Hz to 60 Hz The power supply frequency band of home appliances is allowed to pass, and the frequency band (2 to 30 MHz) used for PLC communication is not allowed to pass, and the second balanced circuit and / or one unbalanced circuit has two wirings Are connected in parallel to the first balanced circuit via two DC cut capacitors connected in series to the power line, and the second balanced circuit is a telephone jack modular jack as a balanced terminal opposite to the power line. And a PLC for noise filter connected to a telephone line which is in equilibrium wiring through a.

  Further, the unbalanced circuit is connected to a coaxial cable which is a non-balanced wiring via a coaxial connector as an unbalanced terminal opposite to the power line.

  The second balanced circuit is composed of two capacitors connected in series to two wires, and is connected to a modular jack.

  The non-equilibrium circuit is composed of a balun transformer, and one wiring on the opposite side to the power line of the balun transformer is connected to the coaxial connector, and the other wiring is grounded.

  The second balanced circuit is connected as a balanced terminal to a telephone line made of balanced wiring via a telephone line modular jack.

  The wiring on the non-equilibrium circuit that is not grounded is connected to the core wire of the coaxial cable that is the unbalanced wiring through the coaxial connector.

  By adopting such a configuration, the present invention can prevent noise from a household electric appliance or the like that is a noise source from leaking to the PLC modem as in the case of a conventional noise filter.

  Further, in the present invention, a DC cut capacitor and a second balanced circuit are connected to a telephone line which is a balanced wiring, and the telephone line is used to make other noise filters for PLC in the home, a PLC modem, and a PC. By connecting, it is possible to enable in-home communication that has conventionally been difficult between different phases.

  In addition, when a telephone line cannot be used, it is possible to enable in-home communication, which has conventionally been difficult between different phases, by using a coaxial cable for television that is unbalanced wiring.

  In the present invention, the PLC communication is performed between the common phases by the power line as before, and the PLC communication in the home, which has been conventionally difficult between the different phases, can be used for the telephone line and the coaxial for the television set which are already laid regardless of the power line. The noise filter for PLC which can be performed with high quality using a cable can be provided.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  1 to 3 are diagrams for explaining an embodiment of a PLC noise filter according to the present invention, and FIG. 1 shows a configuration example of a PLC noise filter according to the present invention. FIG. 2 is a diagram showing a configuration example using the second balanced circuit 7 according to the present invention. FIG. 3 is a diagram showing a configuration example using the unbalanced circuit 8 according to the present invention.

  The PLC noise filter according to the embodiment of the present invention may be housed in a housing in which terminals are installed in a so-called inlet type noise filter configuration, but the housing and output terminals are schematically shown in FIGS. It shows.

  The PLC noise filter of the present invention is a coaxial jack for connecting to a modular jack 1 for connecting to a telephone line 14 already installed in the home or a coaxial cable 15 for television already installed in the home. It has a connector 2 as a terminal, and has an impedance upper that is a first balanced circuit 6 composed of a coil and a capacitor, a second balanced circuit 7 composed of a capacitor, and / or one unbalanced circuit 8 composed of a balun transformer.

  The first balanced circuit composed of a coil and a capacitor in FIG. 1 is 6, and the power frequency band (50 Hz or 60 Hz) of the home appliance as the noise source 3 passes through as it is, and the signal of the PLC communication frequency band does not pass through. Noise from home appliances does not leak to the side. As a specific example of the first balanced circuit 6, for example, a combination of a 33 nF capacitor and a 4.7 μH coil has an attenuation characteristic of 40 dB or more in the frequency band (2 to 30 MHz) of PLC communication.

  In the present invention, it is possible to perform PLC communication even in rooms between different phases by using a telephone line 14 laid in a conventional home that is no longer used due to the spread of optical fibers.

  As the DC cut capacitor 9 in FIG. 1, a capacitor of about 120 nF can be used.

  As the capacitor constituting the second balanced circuit 7 in FIG. 1, a capacitor of about 120 nF can be used.

  FIG. 6 is a diagram showing an example of Insertion Loss of a balun transformer used in the present invention. As the balun transformer constituting the unbalanced circuit 8 in FIG. 1, a balun transformer having specifications with the representative characteristics shown in FIG. 6 can be used.

  If the PLC noise filter shown in FIG. 1 is used to configure the indoor wiring as shown in FIG. 2, the signal attenuation is unavoidable in the inter-phase communication using the power line described with reference to FIG. For communication between PC 1 and PC 2, the PLC communication signal is superimposed from the indoor power line through the modular jack 1 to the telephone line 14, which is a balanced wiring, and each PLC noise filter and PLC is connected via the telephone line 14. It can be connected to the modem 4 and also has the effect of the DC cut capacitor 9 so that high-quality home communication without attenuation becomes possible.

  When the telephone line 14 cannot be used, if the indoor wiring is configured as shown in FIG. 3 using the PLC noise filter shown in FIG. 1, the different phases using the power line described with reference to FIG. For communication between PC1 and PC2 in which signal attenuation was unavoidable in the communication in the above, the PLC communication signal is superimposed from the indoor power line through the coaxial connector 2 onto the coaxial cable 15 for television, which is an unbalanced wiring, and the coaxial cable. 15 can be connected to each PLC noise filter and PLC modem 4, and there is also an effect of the DC cut capacitor 9, which enables high-quality home communication without attenuation.

  Of course, in-phase communication using a power line can be performed as usual without any problem.

  As described above, by replacing the PLC noise filter according to the embodiment of the present invention with a conventional noise filter, a telephone line or a coaxial cable can be used for communication wiring between rooms where power lines are wired in different phases. Can be used for communication. Further, the wiring is not complicated as in the case of connecting another device to the conventional noise filter.

  Needless to say, the present invention is not limited to such an embodiment, and the housing, terminals, and shapes used in the present invention can be arbitrarily designed according to the purpose.

The figure for demonstrating embodiment of the noise filter for PLC by this invention, The figure which shows the structural example of the noise filter for PLC by this invention. The figure for demonstrating embodiment of the noise filter for PLC by this invention, The figure which shows the structural example using the balanced circuit by this invention. The figure for demonstrating embodiment of the noise filter for PLC by this invention, The figure which shows the structural example using the unbalanced circuit by this invention. The figure of the noise filter used conventionally from the coil and capacitor | condenser which are the basis of this invention. The block diagram at the time of connecting the apparatus for PLC communications, and the noise filter conventionally used to the indoor electric power line of the general household used as the basis of this invention. The figure which shows an example of Insertion Loss of the balun transformer used by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Modular jack 2 Coaxial connector 3 Noise source 4 PLC modem 5, 17 Outlet 6 1st balanced circuit (impedance upper)
7 Second balanced circuit 8 Unbalanced circuit (balun transformer)
9 DC cut capacitor 10 Opto-electric converter (ONU)
11 Optical cable 12 PC (PC)
13, 16 Noise filter 14 Telephone line 15 Coaxial cable

Claims (4)

A noise filter for PLC used for power line carrier communication (PLC communication), a first balanced circuit disposed between a power line made of balanced wiring and a home appliance connected to the power line, and the first balanced circuit A second balanced circuit or / and one unbalanced circuit connected in parallel to
The first balanced circuit has a function of allowing a power frequency band of household appliances of 50 Hz to 60 Hz to pass and not allowing a frequency band used for PLC communication to pass;
The second balanced circuit and / or one unbalanced circuit is connected in parallel to the first balanced circuit via two DC cut capacitors connected in series to two wires,
The PLC noise filter according to claim 1, wherein the second balanced circuit is connected to a telephone line formed of a balanced wiring via a telephone line modular jack as a balanced terminal opposite to the power line.   2. The PLC noise filter according to claim 1, wherein the unbalanced circuit is connected to a coaxial cable, which is a non-balanced wiring, via a coaxial connector as an unbalanced terminal opposite to the power line.   The said 2nd balanced circuit consists of two capacitors respectively connected in series with two wiring, and is connected to the said modular jack, The one of Claim 1 thru | or 2 characterized by the above-mentioned. PLC noise filter.   4. The non-equilibrium circuit is composed of a balun transformer, and one wiring on the opposite side to the power line of the balun transformer is connected to the coaxial connector, and the other wiring is grounded. The noise filter for PLC of Claim 1.

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