JP2008118658A - Broadband blocking filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blocking filter for easily installing a blocking filter within a distribution panel, user terminal wall socket and modem and improving communication signal stability and maintainability by providing a small-sized blocking filter in high-speed power line communications. <P>SOLUTION: The broadband blocking filter is configured by including a high-power inductor and a capacitor, a circuit pattern for electrically connecting the inductor and the capacitor; a printed circuit board on which the inductor and the capacitor are disposed and the circuit pattern is formed; and a case for housing the printed circuit board therein. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a blocking filter, and more particularly to a broadband high-voltage blocking filter that controls the flow of communication signals between sub-networks and can be installed on a distribution board at home or office.

  High-speed power line communication (PLC) transmits and receives high-frequency signals of several hundred KHz to several tens of MHz or more using power lines that are already widely used in most homes and offices. Such high-speed power line communication can be connected to an ultra-high-speed Internet line and a telephone line, and can transmit voice, text, video data, and the like.

  The biggest advantage of high-speed power line communication is that unlike other wired network systems, a network can be built using existing power lines without additional wiring work, and a communication network is installed. It is possible to connect to a super-high-speed Internet line and a telephone line even in places where there is no access.

  On the other hand, a disadvantage of high-speed power line communication is that, in high-speed power line communication, a large number of power line networks can be formed, so that one unintended network and another network are connected in communication. That is, A household, B household, and C household that perform high-speed power line communication using a power line form a network of the same protocol, and are communicably connected by one power line. In this way, when households are communicably connected with one power line, a communication signal including at least one of voice, text, and video data is transmitted to a modem installed in household A. There is a risk of communication signals leaking to B or C households through the power line. That is, the communication signal transmitted to the A household not only has poor security and stability, but also has problems such as communication signal distortion, transmission delay, and bandwidth reduction.

  In addition, homes and offices that perform high-speed power line communication using power lines are connected to street lights installed nearby by the same power line, so that electromagnetic waves emitted from street light lines and ballasts are transmitted to homes and offices. By acting as a noise on the communication signal, the communication signal is distorted and the bandwidth is reduced.

  A blocking filter that can solve these problems has been developed, but it is a size that occupies a considerable area for installation in a home or office. Due to problems, general consumers are less willing to purchase.

  Moreover, the conventional blocking filter is used for the power line which uses an outdoor environment and uses a high voltage. Therefore, the size of the inductor and the capacitor was very large.

  Accordingly, there is a need for a blocking filter of an appropriate size that can be applied to high-speed power line communication and can be installed on a distribution board at home or office.

Korean Utility Model Application Publication No. 1992-007129 JP 2003-069728 A JP 2003-174349 A JP 2005-203915 A JP 2005-203916 A

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems, and by providing a blocking filter that is miniaturized in high-speed power line communication, it is possible to easily block power distribution boards, consumer terminal power outlets, and modems. An object of the present invention is to provide a blocking filter that can be provided with a filter to increase the stability and security of communication signals. In addition, a device suitable for indoor use in a relatively low voltage environment is provided.

  Another object of the present invention is to provide a blocking filter having an inductor that is excellent in thermal efficiency in a place where high-speed power line communication is performed and can be used in a circuit through which high power flows.

  To achieve the above object, a broadband blocking filter according to an embodiment of the present invention includes a high power inductor and a capacitor, a circuit pattern for electrically connecting the inductor and the capacitor, and the inductor and the capacitor. A printed circuit board on which the circuit pattern is formed and a case for storing the printed circuit board are included.

  To achieve the above object, a broadband blocking filtering system according to an embodiment of the present invention includes a power line that provides a path for a high power signal to travel, and a plurality of sub-networks that are communicatively coupled to the power line. A blocking filter that is installed at the end of the subnetwork and blocks a flow of communication signals transmitted and received in the respective subnetwork through the power line.

  According to the broadband blocking filter according to the embodiment of the present invention, the flow of communication signals in the communicatively connected network is controlled by installing the blocking filter in the power outlet and the distribution board at the place where the high-speed power line communication is performed. In addition, the stability and security of the communication signal can be increased.

  According to the broadband blocking filter according to another embodiment of the present invention, it is possible to provide an inductor that is excellent in thermal efficiency in a place where high-speed power line communication is performed and can be used for a circuit through which high power flows.

  The preferred embodiments of the present invention are disclosed for illustrative purposes, and those skilled in the art can make various modifications, changes, additions, etc. within the spirit and scope of the present invention. Such modifications, changes and the like must be regarded as belonging to the claims.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the following description is made for explaining the embodiments of the present invention, and the present invention is limited to these embodiments. is not. The same or the same type of elements are denoted by the same or related symbols, and redundant description is omitted.

  1 and 2 are diagrams schematically illustrating a high-speed power line communication system including a blocking filter according to an embodiment of the present invention.

  Referring to FIG. 1, the first sub-network (101), the second sub-network (102), and the third sub-network (103) are networks having the same protocol. It is linked with. Such first to third sub-networks (101 to 103) include a blocking filter (190) on the side connected to the first power line (200), so that the flow of communication signals in the sub-networks (101 to 103) To control. The first to third sub-networks (101 to 103) are connected to a dedicated line (300) provided by an ISP (Internet Service Provider).

  In addition, the first to third sub-networks (101 to 103) are provided with a blocking filter (190) in order to solve the phenomenon that the distortion and bandwidth of the communication signal by the ballast (105) are reduced.

  As shown in FIG. 2, the first to third sub-networks (101 to 103) are connected to the streetlight (104) via the first power line (200). Accordingly, electromagnetic waves generated from the ballast (105) of the streetlight (104) and impedance due to the streetlight line flow into the first to third sub-networks (101 to 103) through the first power line, and distortion and bandwidth of the communication signal. Causes a width reduction. Such first to third sub-networks (101 to 103) are provided with a blocking filter (190a) on one side to block the electromagnetic wave generated from the ballast (105) and the impedance due to the streetlight line. Yes.

  FIG. 3 is a diagram schematically illustrating first to third sub-networks (101 to 103) in which blocking filters according to an embodiment of the present invention are installed. Since the configurations of the first to third sub-networks (101 to 103) according to the embodiment of the present invention are the same, only the first sub-network (101) will be described here. Detailed description of the third sub-network (102 and 103) is omitted. The first subnetwork (101 to 103) includes a master device (130), a slave device (150), and a switchboard (170).

  The master device (130) is a device directly connected to a dedicated line (300, not shown in FIG. 3) for receiving an XDSL signal provided by the ISP. The master device (130) applies a communication signal to the slave device (150). The master device (130) is connected to a switchboard (170) provided in the first sub-network (101).

  Since the slave device (150) is connected to the master device (130) via the second power line (250), the communication signal transmitted to the master device (130) is applied. The slave device (150) is connected to a switchboard (170) arranged in the first subnetwork (101). Such a slave device (150) is preferably a communication device.

  The switchboard (170) includes a fuse (180) and a blocking filter (190).

  The fuse (180) has one side connected to the first power line (200) and the other side connected to the blocking filter (190). The fuse 180 is an automatic circuit breaker for preventing an overcurrent from flowing through the second power line 250 installed in the first sub-network 101.

  The blocking filter (190) has one side connected to the fuse (180) and the other side connected to the master device (130) and at least one slave device (150). The blocking filter 190 transmits a communication signal including at least one of audio, text, and video data in the first subnetwork 101 through the first power line 200 to the second subnetwork 102 and the third subnetwork. It plays the role of preventing transmission to the network (103). That is, when the communication signal transmitted to the master device (130) is applied to at least one slave device (150) through the second power line (250), the blocking filter (190) is connected to the slave device (150). The communication signal is prevented from leaking to the second sub-network (102) or the third sub-network (103) through the connected first power line (200). Conversely, the blocking filter 190 prevents communication signals in the second subnetwork 102 and the third subnetwork 103 from leaking to the first subnetwork 101 through the first power line 200. is doing.

  The blocking filter 190 includes a printed circuit board on which the first to fourth inductors (L1 to L4), the first and second capacitors (C1 and C2), and the first to third resistors (R1 to R3) are disposed. It consists of a case for mounting a printed circuit board. Such a blocking filter (190) will be described in detail below.

  FIG. 4 is a circuit diagram of the blocking filter according to the first embodiment of the present invention. The blocking filter 190a is disposed between the first AC line (AC_1) and the second AC line (AC_2). In the first AC line (AC_1), the first and second inductors (L1, L2) are arranged in series from the output end to the input end. A first contact (N1) is provided between the output terminal (OUT_1) of the first AC line (AC_1) and the first inductor (L1). The first contact (N1) and the first inductor (L1) A second contact (N2) is provided between the two. Further, between the first inductor (L1) and the second inductor (L2), the third contact (N3), the fourth contact (N4), and the fifth contact (N5) are sequentially arranged from the first inductor (L1) side. ) Is provided. Further, in the second AC line (AC_2), the third and fourth inductors (L3, L4) are arranged in series from the output end to the input end in the same manner as the first AC line (AC_1). . A sixth contact (N6) is provided between the output terminal (OUT_2) of the second AC line (AC_2) and the third inductor (L3). The sixth contact (N6) and the third inductor (L3) A seventh contact (N7) is provided in between. Further, between the third inductor (L3) and the fourth inductor (L4), the eighth contact (N8), the ninth contact (N9), and the tenth contact (N10) are sequentially arranged from the third inductor (L3) side. ) Is provided.

  The first contact (N1) and the sixth contact (N6) are connected by the first capacitor (C1), and the second contact (N2) and the seventh contact (N7) are connected by the first resistor (R1). . In addition, the third capacitor (N3) to the eighth contact (N8), the fourth contact (N4) to the ninth contact (N9), and the fifth contact (N5) to the tenth contact (N10) are respectively connected to the second capacitor. (C2), the second resistor (R2), and the third resistor (R3) are connected.

  For example, the first AC line (AC_1) in which the first and second inductors (L1, L2) are arranged in series from the output end to the input end, and the third and the same from the output end to the input end. In the second AC line (AC_2) in which the fourth inductors (L3, L4) are arranged in series, the first AC line (AC_1) on the output end side from the first and third inductors (L1, L3). Between the first and second contacts (N1, N2) from the output end side of the first and the sixth and seventh contacts (N6, N7) from the output end side on the second AC line (AC_2), respectively. A circuit connecting the capacitor (C1) and the first resistor (R1) can be used. Further, on the first AC line (AC_1), which is on the input end side from the first and third inductors (L1, L3) and on the output end side from the second and fourth inductors (L2, L4). Third, fourth, and fifth contacts (N3, N4, N5) from the output end side, and eighth, ninth, and tenth contacts (N8, N9) from the output end side on the second AC line (AC_2) , N10), a circuit connecting the second capacitor (C2), the second resistor (R2), and the third resistor (R3) can be used.

  Since this blocking filter (190a) is a single-phase circuit, either the first AC line (AC_1) or the second AC line (AC_2) is a power line, and the other is a neutral line. That is, since the second AC line (AC_2) becomes a neutral line if the first AC line (AC_1) becomes a power supply line, the second AC line (AC_2) acts as a virtual ground line (GND_line). Further, if the second AC line (AC_2) becomes a power supply line, the first AC line (AC_1) becomes a neutral line, and therefore the first AC line (AC_1) acts as a virtual ground line (GND_line).

  FIG. 5 is a circuit diagram when the second AC line (AC_2) is a virtual ground line (GND_line). The blocking filter (190a) circuit includes first and second capacitors (C1, C2), first and second inductors (L1, L2), and first to third resistors (R1 to R3).

  At this time, the first capacitor (C1) and the first inductor (L1) constitute a first low pass filter (hereinafter referred to as LPF). Further, the second capacitor (C2) and the second inductor (L2) constitute a second LPF. The first capacitor (C1) passes high frequency components, and the first inductor (L1) passes low frequency components.

  The first LPF makes use of the properties of the first capacitor C1 and the first inductor L1 to the slave device 150 through the second power line 250 in the first sub-network 101. Communication signals in the frequency band of 2 to 30 MHz that are transmitted and received can be blocked. The second LPF also plays the same role as the first LPF. Therefore, when a communication signal including at least one of voice, text, and video data is transmitted / received using a power line, it is generally sent on a frequency band of 2 to 30 MHz. A communication signal in a frequency band of 2 to 30 MHz that flows from the output terminal (OUT_1) of (AC_1) to the input terminal (IN) is filtered for components in the frequency band of 2 MHz or more through the first LPF and the second LPF. As described above, the communication signal passing through the first LPF and the second LPF cannot pass through the frequency band component of 2 MHz or more on which the communication signal is placed, and only the frequency band component of 2 MHz or less is passed to the input terminal (IN). Inflow. Even if the frequency band component of 2 MHz or less flowing into the input terminal (IN) flows into the second and third sub-networks (102 and 103), the security and stability of the communication signal are particularly affected. Absent.

  Further, the communication signal remaining in the first capacitor C1 and the second capacitor C2 prevents the communication signal passing through the first LPF and the second LPF from being filtered, so that the first capacitor C1 and A first resistor (R1) is arranged in parallel, and a second resistor (R2) and a third resistor (R3) are arranged in parallel with the second capacitor (C2). The communication signal remaining in the first capacitor (C1) is removed by flowing through the first resistor (R1), and the communication signal remaining in the second capacitor (C2) is removed from the second resistor (R2). And it is removed by flowing through the third resistor (R3). Since the first resistance (R1) value is preferably the same as the combined value of the second resistance (R2) and the third resistance (R3), the values of the first resistance (R1) and the second resistance (R2) are the same. If so, the third resistor (R3) can be excluded by a blocking filter circuit.

  FIG. 6 is a circuit diagram when the first AC line (AC_1) is a virtual ground line (GND_line). The circuit operates in the same manner as the circuit in which the second AC line (AC_2) is a virtual ground line (GND_line). At this time, the first capacitor (C1) and the third inductor (L3) constitute a first LPF. Further, the second capacitor (C2) and the fourth inductor (L4) constitute a second LPF. Since other components and operations are the same as the circuit (see FIG. 5) of the second AC line (AC_2) of the virtual ground line (GND_line), detailed description thereof is omitted.

  FIG. 7 is a perspective view illustrating an inductor provided in the broadband blocking filter according to the embodiment of the present invention. The first to fourth inductors (L1 to L4) provided in the blocking filter (190a) are provided in the blocking filter (190a), and the coil (194) is provided on the outer peripheral surface of the cylindrical ferrite (192). An inductor that is wound in a spiral shape, and the value of the inductor (L) changes according to the number of turns. Such inductors (L1 to L4) can be used for circuits in which high power flows, but in particular, they can be applied to circuits in which 50 amps flow, and a coil is added to an annular magnet that has been used in the past. Thermal efficiency is improved over wound inductors.

  FIG. 8 is a diagram schematically illustrating the actual size of the blocking filter according to the first embodiment of the present invention. The blocking filter (190a) is larger than a normal cigarette box. However, since it is considerably reduced in size compared to the blocking filter that has been used conventionally, it is a size that is easy to carry and light in weight. Although the blocking filter 190a is determined according to the size of the printed circuit board mounted on the case, the size of the printed circuit board is preferably 19 cm wide, 10 cm long, and 15 cm high. Accordingly, the case of the blocking filter 190a is formed to be larger than the size of the printed circuit board so that the inductor, the capacitor, and the resistor disposed on the printed circuit board do not protrude outside when the printed circuit board is stored. Therefore, it is preferable that the internal space of the case of the blocking filter (190a) is 19 cm wide, 10 cm long, and 15 cm high so that it does not shake when the printed circuit board is stored. As described above, the blocking filter (190a) according to the embodiment of the present invention is small in size so that it can be installed in a switchboard, distribution board, or power line modem, and is easy to carry, so it is installed in a home or office. be able to.

  FIG. 9 is a circuit diagram of a blocking filter according to the second embodiment of the present invention. The blocking filter (190b) according to the second embodiment of the present invention is a connector that can be used by directly plugging into a household plug (see FIGS. 11 and 12). The blocking filter (190b) has a plug (300) for connecting to a household outlet (not shown) at the input end (AC IN), and an outlet (AC OUT) for connecting to a power line modem (AC OUT). 400).

  The blocking filter circuit of the blocking filter (190b) is a circuit for using a single-phase power supply, and one AC power line (AC Line) branched from the plug (300) is connected to an AC power line (AC Line). ) Are connected in series with a fuse (FUSE) and a first inductor (L1) for protecting the internal circuit from an overcurrent. The second inductor (L2) is connected to the other neutral line. Further, a capacitor (C1) for a low-pass filter (LPF), a first resistor (R1), and a third are disposed between the first and second inductors (L1, L2) and the outlet (400) serving as an output terminal. An impedance matching circuit (500) connected in series with the resistor (R3) is interposed. As a result, the AC power supply line (AC Line) and the neutral line (Neutral line) are connected in parallel.

  Here, the impedance matching circuit 500 includes a resistor R2 and a capacitor C2 connected in parallel. Thus, the capacitor (C1), the first resistor (R1), the third resistor (R3), and the impedance matching connected in parallel between the AC power line (AC Line) and the neutral line (Neutral line). A circuit (500) may be included.

  The impedance matching circuit 500 is connected in series to a third resistor R3, a first node N1 provided between the first inductor L1 and the outlet 400, and a second inductor (N1). L2) to the second node (N2) provided between the outlet (400). The impedance matching circuit (500) matches impedance values that are variable by an external device (power line modem, electric / electronic product, etc.) connected to the outlet (400).

  10 to 12 are actual implementation examples of the blocking filter 190b according to the second embodiment of the present invention. FIG. 10 is a diagram showing a pattern in which the blocking filter circuit of FIG. 9 is actually applied. 11 and 12 are views showing the outer shape of the blocking filter according to the second embodiment of the present invention. As described in the first embodiment, such a blocking filter (190b) blocks a frequency signal in the 2 to 30 MHz band flowing out to another external sub-network connected through one power line and connects to the power line. The noise generated from the general electric and electronic products is cut off, and the variable impedance change is cut off to provide a stable power line environment.

  FIG. 13 is a circuit diagram of a blocking filter according to a third embodiment of the present invention. FIG. 14 is an actual implementation example of a blocking filter to which the circuit of FIG. 13 is applied. The circuit of the blocking filter (190c) according to the third embodiment of the present invention uses single-phase power as in the series type. The circuit of the blocking filter (190c) includes a first node (N1) and a second node (N2) formed on one line connecting an AC power line (AC Line) and a neutral line (Neutral Line), and a smoothing capacitor. (C1) and a low pass filter (LPF).

  The smoothing capacitor C1 is connected between the first node N1 and the second node N2 to remove noise drawn from the outside.

  The low pass filter (LPF) is connected to the AC power line (AC Line) and the neutral line (Neutral Line) at the first node (N1) and the second node (N2). The low-pass filter (LPF) is an RC filter circuit, and filters frequency signals in the 2 to 30 MHz band as described in the first and second embodiments.

  In addition, an impedance matching circuit (500) for matching an external impedance can be added to the blocking filter (190c) in the same manner as the serial blocking filter (190b) described in the second embodiment.

  The blocking filter (190c) is for solving the installation problem of the serial blocking filter (190b) according to the second embodiment. In general, power line communication equipment such as power line modems and blocking filters should be installed after turning off the power line to prevent malfunction of the equipment and the introduction of distorted signals during network setup. Yes. However, since the blocking filter (190c) according to the third embodiment of the present invention can be installed without cutting off the electric power, it can be installed under conditions where the power supply cannot be cut off. Furthermore, by processing the contact portion (600) with a high-performance magnet together with downsizing, the installation can be further simplified, and the problems of the installation position and size can be solved.

  15 and 16 are graphs showing various forms of communication signals input to the sub-network according to the embodiment of the present invention. FIG. 15 is a graph before the blocking filter (190a) is installed in the first to third sub-networks (101 to 103), and FIG. 16 is a graph after the blocking filter (190a) is installed. The graphs on the left side of FIGS. 15 and 16 represent frequency analysis of communication signals. The vertical and horizontal axes of these graphs indicate amplitude and frequency, respectively. The graphs on the right side of FIGS. 15 and 16 represent the analysis of the change over time of the communication signal. The vertical and horizontal axes of these graphs indicate the amplitude and time, respectively.

  As shown in FIG. 15, the first to third sub-networks (101 to 103) include at least one of voice, text, and video data due to interference by the streetlight (104) line and the ballast (105). It can be confirmed that noise is generated in the communication signal in the frequency band of ˜30 MHz and the bandwidth of the communication signal is reduced. On the other hand, as shown in FIG. 16, the first to third sub-networks (101 to 103) are provided with blocking filters (190a) in the first to third sub-networks (101 to 103). It can be confirmed that distortion of the input communication signal due to the interference between the street lamp line and the ballast and the reduction of the bandwidth can be prevented.

  As described above, the blocking filter according to the embodiment of the present invention not only improves the reliability of the safety and stability of the communication signal in the home or office, but also uses the streetlight line and the ballast in the frequency band of 2 to 30 MHz. Noise generation and bandwidth reduction phenomena can be eliminated.

The figure which showed roughly the high-speed power-line communication system provided with the blocking filter which concerns on 1st Example of this invention. 1 is a diagram schematically illustrating a high-speed power line communication system including a blocking filter according to a first embodiment of the present invention. FIG. 3 is an exemplary diagram schematically illustrating the subnetwork illustrated in FIG. 1 or FIG. 2. FIG. 4 is a circuit diagram of a blocking filter illustrated in FIG. 3. FIG. 5 is a circuit diagram showing that the blocking filter circuit shown in FIG. 4 is driven in various ways. FIG. 5 is a circuit diagram showing that the blocking filter circuit shown in FIG. 4 is driven in various ways. FIG. 5 is a diagram schematically illustrating an inductor arranged in the blocking filter circuit diagram illustrated in FIG. 4. FIG. 3 is an exemplary diagram schematically showing an actual size of the blocking filter according to the first embodiment of the present invention. The blocking filter circuit diagram which concerns on 2nd Example of this invention. The figure which shows the pattern where the blocking filter circuit based on 2nd Example of this invention was actually applied. The figure which showed the external shape of the blocking filter which concerns on 2nd Example of this invention. The figure which showed the external shape of the blocking filter which concerns on 2nd Example of this invention. The blocking filter circuit diagram which concerns on 3rd Example of this invention. The figure which showed the actual implementation example of the blocking filter to which the circuit of FIG. 13 was applied. The figure which showed the effect of the blocking filter which concerns on the Example of this invention. The figure which showed the effect of the blocking filter which concerns on the Example of this invention.

Explanation of symbols

100: Subnetwork
130: Master device
150: Slave device
170: Switchboard
190 (190a, 190b, 190c): Blocking filter
200: First power line
250: Second power line
300: Plug, dedicated line
400: Outlet
500: Impedance matching circuit
600: Contact area

Claims (11)

High power inductors and capacitors,
A circuit pattern for electrically connecting the inductor and the capacitor;
A printed circuit board on which the inductor and the capacitor are disposed and the circuit pattern is formed;
A broadband blocking filter comprising: a case for storing the printed circuit board.   The broadband blocking filter according to claim 1, further comprising a resistor connected in parallel with the capacitor. The size of the printed circuit board is:
The broadband blocking filter according to claim 1, wherein the horizontal length is 12 to 19 cm, and the vertical length is 4 to 10 cm. The case is
The horizontal and vertical lengths are formed to be greater than the horizontal and vertical lengths of the printed circuit board,
2. The broadband blocking filter according to claim 1, wherein the height is 2 to 15 cm. The inductor and capacitor operate as a low pass filter,
The broadband blocking filter according to claim 1, wherein the low-pass filter filters a communication signal in a frequency band of 2 to 30 MHz on which at least one of voice, text, and video data is placed. The capacitor and resistor operate as a low pass filter,
The broadband blocking filter according to claim 2, wherein the low-pass filter filters a communication signal in a frequency band of 2 to 30 MHz on which at least one of voice, text, and video data is placed. The low pass filter is
7. The broadband blocking filter according to claim 5, further comprising an impedance matching circuit in which a resistor and a capacitor are connected in parallel, and an impedance matching circuit that matches an impedance value that changes according to connection of an external device is matched. The inductor is
The broadband blocking filter according to claim 1, wherein a coil is formed in a spiral shape on the outer peripheral surface of the cylindrical ferrite. A power line that provides a path for high-power signals to travel;
A number of sub-networks communicatively coupled to the power line;
A wideband blocking filtering system, comprising: a blocking filter that is installed at a terminal of the subnetwork and blocks a flow of communication signals transmitted and received in the respective subnetwork through the power line. The subnetwork is:
A street light stabilizer that controls the current flowing through the street light,
The broadband blocking filtering system according to claim 9, wherein the broadband blocking filtering system is a distribution board, a distribution board, or a power line modem including the blocking filter. The blocking filter is
10. The broadband blocking filtering system according to claim 9, wherein a communication signal in a frequency band of 2 to 30 MHz carrying at least one of voice, text and video data is filtered.