Surge protection device for communication lines

Abstract

This invention provides a surge protection device that does not require grounding or power lines and can be installed on PoE-compatible communication cables. [Solution] The surge protection device 10 is installed on a PoE-compatible communication line 5 that connects the transmitting device 2 and the power receiving device 3 and is capable of transmitting and receiving data signals and supplying power. The surge protection device 10 is connected to the PoE-compatible communication line 5 and includes a splitter 11 that separates the data signal and power output to the communication line 5, a signal line 15 that is connected to the splitter 11 and transmits the data signal separated by the splitter 11, a power supply line 16 that is connected to the splitter 11 and transmits the power separated by the splitter 11, an injector 12 that is connected to the signal line 15 and the power supply line 16 and outputs the data signal and power to the PoE-compatible communication line 5, a first surge protection element 13 installed on the signal line 15, and a second surge protection element 14 installed on the power supply line 16.

Description

Technical Field

[0001] The present invention relates to a surge protection device, and more particularly to a surge protection device provided in a communication line compatible with PoE.

Background Art

[0002] Devices such as network cameras operate by being connected to a transmitting device such as a switching hub via a communication cable (communication line) such as a LAN cable. When a network camera is used for security and surveillance purposes, the network camera is often installed on a ceiling or outdoors, but generally there is no power supply on the ceiling or outdoors. Therefore, in addition to the communication cable, a power supply cable must be installed, and ensuring power supply has been a problem.

[0003] In recent years, a method called PoE (Power over Ethernet (registered trademark)) has been developed to supply power together with a data signal through a communication cable. By using PoE technology, it becomes unnecessary to lay a power supply cable, so it becomes easier to install a network camera even in a place where it is difficult to secure power.

[0004] Communication cables have originally been used for connecting electronic devices in an indoor network, and since they are less affected by abnormal voltages (surge voltages) from lightning or power transmission lines, protection measures have not been so necessary. However, as described above, since the cases of installing electronic devices in an indoor network outdoors have increased, it has become necessary to take surge protection measures for communication cables.

[0005] One surge protection measure is to interpose SPDs (Surge Protectors, Protectors) in communication cables (for example, Patent Document 1). Two types of SPDs are known: discharge-type SPDs and isolation-type SPDs. Discharge-type SPDs use discharge-type surge protection elements such as lightning tubes and varistors to reduce the circuit impedance in response to abnormal voltages, thereby suppressing and protecting the equipment being protected from abnormal voltages. Isolation-type SPDs use isolation-type surge protection elements to insulate the circuit from abnormal voltages and protect the equipment being protected.

[0006] However, since PoE supplies DC power, PoE-compatible communication cables (hereinafter also referred to as "PoE cables") that supply data signals and power to electronic devices cannot be equipped with insulated SPDs, and must instead be equipped with discharge SPDs. However, since discharge SPDs require a grounding wire, a separate grounding wire must be installed for the discharge SPD, which necessitates securing installation space, material costs, and construction costs.

[0007] Isolated SPDs do not require a grounding wire, but as mentioned above, they cannot be installed in PoE cables and are used in communication cables that transmit only data signals (hereinafter also referred to as "signal lines" or "signal cables"). Therefore, when installing isolated SPDs for powered devices such as PoE-compatible network cameras and IP phones, a system 100 like the one shown in Figure 6 is configured. A switching hub 102 connected to a power supply 101 is connected to an injector 103 by a signal cable 104. Isolated SPDs 105 are installed at two locations on the signal cable 104: one near the switching hub 102 and another near the injector 103. The injector 103 is also connected to a power supply 107 by a power supply cable 106. Surge protection transformers 108 are connected to the power supply cable 106 at two locations: one near the power supply 107 and another near the injector 103. A PoE-compatible network camera 109 is connected to the injector 103 by a PoE cable 110. The injector 103 is connected to a signal cable 104 and a power supply cable 106.

[0008] Data signals from the switching hub 102 are transmitted to the injector 103 via the signal cable 104. Power is supplied to the injector 103 via the power supply cable 106. The injector 103 combines the data signals from the signal cable 104 and the power from the power supply cable 106 to produce a PoE-compatible output, which is then supplied to the network camera 109 via the PoE cable 110. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Special Publication No. 2015-529431 [Overview of the project] [Problems that the invention aims to solve]

[0010] In system 100 in Figure 6, an isolated SPD 105 is used, eliminating the need for a grounding wire, but a power supply cable 106 must be connected to the injector 103. Furthermore, surge protection devices such as a lightning protection transformer 108 are also required for the power supply cable 106, making the configuration complex. Originally, using PoE had the advantage of eliminating the need for the power supply cable 106 and reducing the number of cables, but in system 100 in Figure 6, the number of cables cannot be reduced.

[0011] The present invention has been made in view of the above-mentioned problems, and aims to provide a surge protection device that can be installed in a PoE-compatible communication cable and does not require a ground wire or power wire. [Means for solving the problem]

[0012] To achieve the above objectives, the present invention encompasses the subject matter described in the following sections.

[0013] Item 1: A surge protection device installed on a PoE-compatible communication line that connects a transmitting device and a receiving device and is capable of transmitting and receiving data signals and supplying power, A splitter connected to the aforementioned communication line, which separates the data signal and power transmitted to the communication line by the transmitting device, A signal line connected to the aforementioned splitter and transmitting data signals separated by the splitter, A power supply line connected to the aforementioned splitter and transmitting the power separated by the splitter, An injector connected to the signal line and the power supply line, which outputs the received data signal and power to the communication line, A first surge protection element provided on the signal line, A surge protection device comprising a second surge protection element provided in the power supply line.

[0014] Item 2: A substrate on which the splitter, the signal line, the power supply line, the injector, the first surge protection element, and the second surge protection element are provided, The surge protection device according to item 1, comprising a housing for housing the aforementioned substrate.

[0015] Item 3: A first port connected to the splitter, into which data signals and power are input from a PoE-compatible communication line, The surge protection device according to item 2, further comprising a second port connected to the injector and outputting data signals and power to a PoE-compatible communication line.

[0016] Item 4: In a plan view, the substrate is, It is divided into a pattern region where a pattern is formed and a patternless region where no pattern is formed. The surge protection device according to claim 2 or 3, wherein the first surge protection element is provided across a patternless area.

[0017] Item 5: The surge protection device according to Item 4, wherein slits are provided in areas without the pattern that overlap with the first surge protection element.

[0018] Item 6: The substrate is rectangular in shape, The surge protection device according to any one of items 2 to 5, wherein the first surge protection element is provided on one side along the long side of the rectangular shape, and the second surge protection element is provided on the other side along the long side of the rectangular shape.

Effects of the Invention

[0019] According to the present invention, it is possible to provide a surge protection device that does not require a ground wire or a power line and can be provided in a PoE-compatible communication cable.

Brief Description of the Drawings

[0020] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of a system provided with a surge protection device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing a schematic configuration of the surge protection device. [Figure 3] FIG. 3 is a plan view of a substrate. [Figure 4] FIG. 4 is a plan view of a substrate on which components are mounted. [Figure 5] FIG. 5 is a perspective view of a housing. [Figure 6] FIG. 6 is an explanatory diagram showing the prior art.

Embodiments for Carrying Out the Invention

[0021] An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a system 1 provided with a surge protection device 10 of the present embodiment, and FIG. 2 is a block diagram for explaining the configuration of the surge protection device 10 of the present embodiment.

[0022] (Configuration of System 1 Equipped with Surge Protection Device 10) The system 1 includes a transmitting device 2 (also referred to as a "power supply device" or "PSE") connected to a power supply 4, a receiving device 3, a PoE-compatible communication line 5 (hereinafter also referred to as a "communication cable 5") connecting the transmitting device 2 and the receiving device 3, and a surge protection device 10 provided in the middle of the communication cable 5.

[0023] Transmitting device 2 outputs data signals and power to communication cable 5. In the following explanation, the signal output by transmitting device 2, that is, the signal with power superimposed on the data signal, is also called the PoE signal. Transmitting device 2 can be, for example, a PoE-compatible switching hub, power adapter, or PoE injector, but any electronic device that is PoE-compatible and can output data signals and power to communication cable 5 is acceptable. PoE (Power over Ethernet®) is a technology that allows transmitting device 2 to send and receive data signals and supply power to powered device 3 via a standard cable compliant with the Ethernet® standard. Various PoE standards such as IEEE802.3af, 802.3at, and 802.3bt are defined depending on the amount of power supplied to powered device 3.

[0024] The PoE-compatible communication cable 5 is an Ethernet® cable, such as a LAN (Local Area Network) cable. The communication cable 5 transmits a PoE signal which is a combination of data signals and power, but it can also transmit only data signals or only power.

[0025] The powered device 3 could be, for example, an internet camera, a wireless LAN (Local Area Network) access point (AP), an IP phone, or a microphone. However, any electronic device that is PoE-compatible and can receive data signals and power from the communication cable 5 is acceptable.

[0026] For example, if the transmitting device 2 is a switching hub and the receiving device 3 is a PoE-compatible internet camera, the switching hub is often installed indoors and the internet camera is often installed outdoors. In this case, the length of the communication cable 5 is longer, ranging from several meters to tens of meters, compared to when connecting electronic devices indoors. In such cases, as shown in Figure 1, surge protection devices 10A and 10B (referred to as "surge protection device 10" unless otherwise specified) are installed at two locations on the communication cable 5: one near the switching hub and the other near the internet camera. More surge protection devices 10 may be installed on the communication cable 5. If the communication cable 5 is short, a surge protection device 10 may be installed at only one location on the communication cable 5.

[0027] (Configuration of surge protection device 10) Figure 2 shows the configuration of the surge protection device 10. The surge protection device 10 comprises a splitter 11, an injector 12, a signal line 15, a power supply line 16, an isolated SPD 13 (first surge protection element), and an isolated DC / DC converter 14 (second surge protection element).

[0028] The splitter 11, also known as a "PoE splitter," is connected to the PoE-compatible communication cable 5 on the transmitting device 2 side, as well as to the signal line 15 and the power supply line 16. It receives the signal (PoE signal) output to the communication cable 5 by the transmitting device 2 and separates it into a data signal and power. The splitter 11 can be any type that can separate the PoE signal received via the communication cable 5 into a data signal and power.

[0029] The signal line 15 connects the splitter 11 and the injector 12, and transmits the data signals separated by the splitter 11 to the injector 12. The signal line 15 may be a LAN cable of the same specifications as the PoE-compatible communication cable 5, or any cable capable of transmitting data signals may be used.

[0030] The power supply line 16 connects the splitter 11 and the injector 12 and transmits the power separated by the splitter 11. The power supply line 16 may be a LAN cable of the same specifications as the PoE-compatible communication cable 5, or any cable capable of transmitting power may be used.

[0031] The injector 12, also known as a "PoE injector," is connected to the signal line 15 and the power supply line 16, as well as to the PoE-compatible communication cable 5 on the power receiving device 3 side. It combines the data signal transmitted from the signal line 15 and the power supplied from the power supply line 16 into a single PoE signal and outputs it to the communication cable 5. The injector 12 only needs to be capable of combining the data signal and power and outputting it as a PoE signal. The injector 12 is driven by the power supplied from the power supply line 16.

[0032] The first surge protection element is provided on the signal line 15. In this embodiment, an isolated SPD 13 (Surge Protective Device) is used as the first surge protection element. The isolated SPD 13 is equipped with an isolated surge protection element and protects the transmitting equipment 2 and receiving equipment 3, which are the targets of protection, by isolating the circuit from abnormal voltages. For example, the isolated SPD 13 model number OLA-PT1000 manufactured by Otowa Electric Industry Co., Ltd. is used. The first surge protection element is not limited to the isolated SPD 13, and any element or device that has the function of protecting the transmitting equipment 2 and receiving equipment 3, which are the targets of protection, on the signal line 15 may be used. For example, a photocoupler or an isolated pulse transformer may be used.

[0033] A second surge protection element is provided on the power supply line 16. In this embodiment, an isolated DC / DC converter 14 is used as the second surge protection element. The isolated DC / DC converter 14 includes a transformer and electrically isolates the input side from the output side in the power supply line 16 through which DC current flows. The second surge protection element is not limited to the isolated DC / DC converter 14, but can be any element or device that has the function of protecting the transmitting equipment 2 and receiving equipment 3, which are the targets of protection in the power supply line 16. For example, a module with a DC / DC converter function using an isolation transformer and induction coil may be used.

[0034] (operation) In System 1 shown in Figure 1, the PoE signal, which includes data signals and power, output from the transmitting device 2 is output to the communication cable 5. The surge protection device 10A receives the PoE signal output from the transmitting device 2 via the communication cable 5. The splitter 11 separates the PoE signal into signal and power, outputting the data signal to the signal line 15 and the power to the power supply line 16. The signal line 15 transmits the data signal, and the power supply line 16 transmits the power. The injector 12 receives the data signal and power via the signal line 15 and power supply line 16, and outputs the data signal and power as a single PoE signal to the communication cable 5 on the receiving device 3 side.

[0035] The second surge protection device 10B receives a PoE signal from the communication cable 5 and operates in the same manner as surge protection device 10A. Surge protection device 10B outputs a PoE signal to the communication cable 5, and the powered device 3 receives the PoE signal, which is a data signal and power.

[0036] Since the signal line 15 of the surge protection device 10 is equipped with a first surge protection element, even if an overvoltage (surge voltage) occurs in the communication cable 5 due to lightning, the overvoltage is suppressed by the insulating effect, and the transmitting equipment 2 and the receiving equipment 3 are protected. Furthermore, since the power supply line 16 of the surge protection device 10 is equipped with a second surge protection element, even if an overvoltage occurs in the communication cable 5 due to lightning, the overvoltage is suppressed by the insulating effect, and the transmitting equipment 2 and the receiving equipment 3 are protected.

[0037] In conventional technology, a grounding wire was required when attaching a discharge-type SPD to a PoE-compatible communication cable 5, and an injector 12 was required when using an insulated SPD 13 that did not require a grounding wire, and a power line was required for the injector 12. However, with the surge protection device 10 of this embodiment, surge protection for the transmitting equipment 2 and the receiving equipment 3 is possible simply by attaching the surge protection device 10 to the PoE-compatible communication cable 5. In this way, there is no need to add new power lines or grounding wires, and wiring work is unnecessary. Wiring work requires technique depending on the wiring location and the length of the power lines and grounding wires, and construction costs are high, but by installing the surge protection device 10 of this embodiment, wiring work is unnecessary and construction costs can be reduced.

[0038] (Other embodiments) (Overall configuration of surge protection device 10) Figures 3 to 5 show other embodiments of the surge protection device 10. The surge protection device 10 of this embodiment comprises a circuit board 20 and a housing 40 in which the circuit board 20 is housed. On the circuit board 20 are provided components including a splitter circuit (also called "splitter 11"), a signal line 15, a power supply line 16, an injector circuit (also called "injector 12"), an isolated SPD 13 (first surge protection element), and an isolated DC / DC converter 14 (second surge protection element). Unless otherwise specified, the splitter 11, signal line 15, power supply line 16, injector 12, isolated SPD 13, and isolated DC / DC converter 14 have the same functions and configurations as those in the embodiments shown in Figures 1 and 2, and therefore a detailed explanation is omitted.

[0039] (Circuit board 20) Figure 3 is a plan view of the substrate 20. In Figure 3, components placed on the substrate 20 are not shown. In a plan view, the substrate 20 has four patternless areas 21A to 21D arranged in a roughly cross shape, and these four patternless areas 21A to 21D define the four patterned areas 22A to 22D where patterns are placed. The four patternless areas 21A to 21D are provided to improve the dielectric strength between the four patterned areas 22A to 22D. A pattern is a wire printed on the substrate 20 that connects the various components placed on the substrate 20.

[0040] In this embodiment, the substrate 20 is rectangular in shape. In the plan view shown in Figures 3 and 4, the direction in which the longer side of the rectangular substrate 20 extends is called the first direction or transverse direction, and the direction in which the shorter side of the rectangle extends is called the second direction or longitudinal direction. Furthermore, one side in the longitudinal direction is called the upper side, and the opposite side in the longitudinal direction is called the lower side. One side in the transverse direction is called the left side, and the opposite side in the transverse direction is called the right side.

[0041] In one example, the circuit board 20 is set to have a vertical length of 114 mm, a horizontal length of 166 mm, and a thickness of 1.6 mm.

[0042] In this embodiment, in a plan view, the first unpatterned area 21A is rectangular and extends laterally from the left edge 20c of the substrate 20 in the lateral direction. The second unpatterned area 21B is provided continuously with the first unpatterned area 21A and extends to the right edge 20d of the substrate 20 in the lateral direction. The second unpatterned area 21B is L-shaped, with one side of the L extending laterally and the other side extending vertically. The widths of the first unpatterned area 21A and the second unpatterned area 21B are preferably as large as possible from the viewpoint of insulation, and are determined in consideration of the area occupied by the components provided on the substrate 20. In this embodiment, the widths of the first and second unpatterned areas 21A and 21B are set to 8.0 mm.

[0043] Slits 23A to 23C are provided in the first unpatterned region 21A and the second unpatterned region 21B. Slits 23A to 23C are holes that penetrate the substrate 20 in the thickness direction. In this embodiment, three slits 23A to 23C are provided. The first unpatterned region 21A is provided with a linear slit 23A extending in the lateral direction and an L-shaped slit 23B. The second unpatterned region 21B is provided with an L-shaped slit 23C corresponding to the shape of the second unpatterned region 21B. From the viewpoint of insulation, it is desirable that the area of ​​slits 23A to 23C be large in the first unpatterned region 21A and the second unpatterned region 21B. However, if there are too many slits 23A to 23C, or if the length or width of slits 23A to 23C is too large, the total area of ​​slits 23A to 23C will become too large, which may weaken the strength of the substrate 20 and cause it to crack when screwing it to the housing 40. Therefore, the appropriate number, length, and width are set. In this embodiment, the width of slits 23A to 23C is set to 1 mm, the length of the straight portion of slits 23A to 23C is set to 50 mm or less, and the length between adjacent slits 23A to 23C is set to 1 mm or more.

[0044] The third unpatterned region 21C is rectangular and extends between the first unpatterned region 21A and the upper edge 20a of the substrate 20. The fourth unpatterned region 21D is rectangular and extends between the first unpatterned region 21A and the lower edge 20b of the substrate 20. In this embodiment, the third unpatterned region 21C and the fourth unpatterned region 21D do not have slits from the viewpoint of the strength of the substrate 20, but slits may be provided.

[0045] The shape of the substrate 20 is not limited to a rectangular shape, but may be any shape. Also, the number, length, width, and placement position of the first to fourth patternless areas 21A to 21D, and the number, length, width, and placement position of the slits 23A to 23C are not limited to this embodiment, but can be appropriately determined according to the size of the substrate 20 and the area required to mount components on the substrate 20.

[0046] The first pattern area 22A is the area enclosed by the first unpatterned area 21A, the third unpatterned area 21C, and the upper edge 20a and left edge 20c of the substrate 20. The second pattern area 22B is the area enclosed by the first unpatterned area 21A, the second unpatterned area 21B, the third unpatterned area 21C, and the upper edge 20a and right edge 20d of the substrate 20. The third pattern area 22C is the area enclosed by the first unpatterned area 21A, the second unpatterned area 21B, the fourth unpatterned area 21D, and the lower edge 20b and right edge 20d of the substrate 20. The fourth pattern area 22D is the area enclosed by the first unpatterned area 21A, the fourth unpatterned area 21D, and the lower edge 20b and left edge 20c of the substrate 20.

[0047] Patterns for connecting components are printed in each of the first to fourth pattern regions 22A to 22D. Of the first to fourth pattern regions 22A to 22D, the region where no pattern is printed is ground, and the potential difference with the reference voltage is 0V.

[0048] By providing patternless areas 21A to 21D and slits 23A to 23C, the first to fourth pattern areas 22A to 22D can be isolated from each other, preventing surge voltages caused by lightning from being transmitted to the transmitting equipment 2 and the receiving equipment 3.

[0049] (Components on circuit board 20) As shown in Figure 4, a first port 30 and a splitter 11 are provided in the first pattern area 22A of the substrate 20. A LAN connector (not shown) attached to the end of a communication cable 5 is plugged into the first port 30, connecting the communication cable 5 to the splitter 11 on the substrate 20. The first port 30 is located on the left side of the substrate 20, along the upper edge 20a of the substrate 20. The first port 30 and the splitter 11 are connected by a pattern.

[0050] The fourth pattern area 22D is provided with an injector 12 and a second port 31. A LAN connector (not shown) attached to the end of a communication cable 5 is plugged into the second port 31, connecting the communication cable 5 to the injector 12 on the substrate 20. The second port 31 is located along the lower edge 20b of the substrate 20, aligned vertically with the first port 30. The second port 31 is shielded. The second port 31 and the injector 12 are connected by a pattern.

[0051] An LED indicator 32 is provided on the lower edge 20b of the fourth pattern area 22D of the substrate 20. The LED indicator 32 is connected to a boost circuit 36 ​​by a pattern (not shown) and its illumination and extinguishing are controlled. The LED indicator 32 has two LEDs 32A and 32B (Figure 5), with one LED 32A lit up while receiving a PoE signal from the transmitting device 2, and the other LED 32B lit up while transmitting a PoE signal to the receiving device.

[0052] An isolated SPD 13 is provided spanning the first unpatterned area 21A between the first pattern area 22A and the fourth pattern area 22D. That is, one terminal of the isolated SPD 13 is located in the first pattern area 22A, and the other terminal is located in the fourth pattern area 22D. One terminal of the isolated SPD 13 is connected to the splitter 11 in the first pattern area 22A by a pattern that constitutes a signal line 15, and the other terminal of the isolated SPD 13 is connected to the injector 12 in the fourth pattern area 22D by a pattern that constitutes a signal line 15. Capacitors (not shown) are provided in these patterns that constitute the signal line 15 to isolate the signal line 15 from ground and to regulate the voltage.

[0053] In a plan view, a slit 23A is provided in the first patternless region 21A that overlaps with the insulating SPD 13. The slit 23A is provided at a position that overlaps with the insulating SPD 13 in a plan view.

[0054] A voltage adjustment circuit 33 is provided in the second pattern area 22B. The voltage adjustment circuit 33 adjusts the voltage input to the isolated DC / DC converter 14 and converts the power separated by the splitter 13A into, for example, DC 12V power. The voltage adjustment circuit 33 is composed of a converter controller switch IC and the like. A connection circuit 34, including a transformer and a photocoupler, is provided spanning the third patternless area 21C between the first pattern area 22A and the second pattern area 22B. One terminal of the connection circuit 34 is connected to the splitter 11 in the first pattern area 22A by a pattern that constitutes a power supply line 16, and the other terminal of the connection circuit 34 is connected to the voltage adjustment circuit 33 in the second pattern area 22B by a pattern that constitutes a power supply line 16.

[0055] Furthermore, an insulating capacitor 35A is provided spanning the third patternless region 21C. The insulating capacitor 35A eliminates the potential difference between the first pattern region 22A and the second pattern region 22B, thereby providing isolation.

[0056] An isolated DC / DC converter 14 is provided spanning the second patternless area 21B between the second pattern area 22B and the third pattern area 22C. That is, one terminal of the isolated DC / DC converter 14 is located in the second pattern area 22B, and the other terminal is located in the third pattern area 22C. One terminal of the isolated DC / DC converter 14 is connected to the voltage adjustment circuit 33 in the second pattern area 22B by a pattern that constitutes a power supply line 16, and the other terminal of the isolated DC / DC converter 14 is connected to the boost circuit 36 ​​in the third pattern area 22C by a pattern that constitutes a power supply line 16. In addition, an insulating capacitor 35B is provided spanning the second patternless area 21B. The insulating capacitor 35B eliminates the potential difference between the second pattern area 22B and the third pattern area 22C, thereby providing isolation.

[0057] In a plan view, the slit 23C is positioned to overlap with at least the isolated DC / DC converter 14. In this embodiment, the insulating capacitor 35B is positioned to overlap with the isolated DC / DC converter 14.

[0058] A boost circuit 36 ​​is provided spanning the fourth patternless area 21D between the third pattern area 22C and the fourth pattern area 22D. The boost circuit 36 ​​boosts the voltage of the power output from the isolated DC / DC converter 14 to a voltage corresponding to the powered device, and consists of a switching controller, a PSE controller, a reverse current prevention diode, etc. One terminal of the boost circuit 36 ​​is located in the third pattern area 22C, and the other terminal is located in the fourth pattern area 22D. One terminal of the boost circuit 36 ​​is connected to the isolated DC / DC converter 14 in the third pattern area 22C by a pattern that constitutes the power supply line 16, and the other terminal of the boost circuit 36 ​​is connected to the injector 12 in the fourth pattern area 22D by a pattern that constitutes the power supply line 16.

[0059] Furthermore, an insulating capacitor 35C is provided spanning the fourth patternless region 21D. The insulating capacitor 35C eliminates the potential difference between the third pattern region 22C and the fourth pattern region 22D, thereby providing isolation.

[0060] In a plan view of the substrate 20, an insulated SPD 13 is positioned horizontally along one of the rectangular long sides of the substrate 20, and the pattern for the signal line 15 is provided along the vertical direction, connecting the insulated SPD 13 to the splitter 11 and the injector 12. An insulated DC / DC converter 14 is positioned horizontally along the other of the rectangular long sides of the substrate 20. The pattern for the power supply line 16 is provided in a roughly U-shape with an opening on the left side, parallel to the upper edge 20a, the right edge 20d, and the lower edge 20b of the substrate 20, and connects the insulated DC / DC converter 14 to the splitter 11 and the injector 12. In other words, the insulated SPD 13 and the insulated DC / DC converter 14 are positioned at separate locations on the substrate 20, and the pattern for the power supply line 16, which is parallel to the pattern for the signal line 15, is positioned along the right edge 20d of the substrate.

[0061] When the power supply line 16 and the signal line 15 are placed in close proximity, especially when they are placed parallel to each other, an induced current may flow in the signal line 15, generating noise. However, in this embodiment, the pattern of the signal line 15 and the pattern of the power supply line 16, which is parallel to the pattern of the signal line 15, are placed as far apart as possible on the left and right sides of the substrate in the lateral direction, so noise is less likely to occur.

[0062] (Housing 40) As shown in Figure 5, the housing 40 is a rectangular parallelepiped whose planar shape corresponds to the shape of the substrate 20, and houses the substrate 20 inside. The substrate 20 is fixed inside the housing 40 by mounting means such as screws (not shown). The housing 40 may consist of a housing body and a lid, in which case the housing body and the lid may be separated vertically or horizontally and be detachable. A first opening 41 for exposing the first port 30 is formed on one side of the housing 40, and a second opening 42 for exposing the second port 31 is formed on the side of the housing 40 opposite to the one side. Furthermore, LEDs 32A and 32B of the LED indicator 32 provided on the substrate 20 are fitted into the opening next to the first opening 41.

[0063] According to this embodiment, since components are provided on the substrate 20 and the substrate 20 is housed in the housing 40, the surge protection device 10 can be miniaturized, and a small mounting space is sufficient. Further, the user can configure the system 1 shown in FIG. 1 by simply connecting the communication cable 5 to the first port 30 and the second port 31 of the surge protection device 10.

[0064] Note that the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Expressions indicating that things such as "in a certain direction", "along a certain direction", "the same", "identical", "equal", and "homogeneous" are in an equal state not only represent a strictly equal state, but also represent a state in which there are tolerances or differences within the range where the same function can be obtained. Expressions representing triangular, rectangular, or circular shapes not only represent geometrically precise shapes, but also represent shapes including concavo-convex portions, chamfered portions, etc. within the range where the same effect can be obtained. The expressions "comprising", "having", "including", or "possessing" one component are not exclusive expressions excluding the existence of other components. "Parallel" and "orthogonal" mean substantially "parallel" and "orthogonal", and include not only a strictly "parallel" and "orthogonal" state, but also a state including an error of about several degrees. Also, there are cases where an expression such as "part" is used, for example, "end part". For example, the "end part" means a part having a certain range including the "end". The same applies to other expressions with "part".

Explanation of Signs

[0065] 1 System 2 Transmitter device 3 Power receiving device 4 Power supply 5 Communication cable 10 Surge protection device 11 Splitter 12 Injector 13 Insulated SPD (first surge protection element) 14. Isolated DC / DC converter (second surge protection element) 15 signal line 16 Power supply line 20 circuit boards 30 Port 1 31 Port 2 40 Housing

Claims

1. A surge protection device installed on a PoE-compatible communication line that connects a transmitting device and a receiving device and is capable of transmitting and receiving data signals and supplying power, A splitter connected to the aforementioned communication line receives and separates the data signal and power output to the communication line by the transmitting device, A signal line connected to the aforementioned splitter and transmitting data signals separated by the splitter, A power supply line connected to the aforementioned splitter and transmitting the power separated by the splitter, An injector connected to the signal line and the power supply line, which outputs the received data signal and power to the communication line, A first surge protection element provided on the signal line, A surge protection device comprising a second surge protection element provided in the power supply line.

2. A substrate on which the splitter, the signal line, the power supply line, the injector, the first surge protection element, and the second surge protection element are provided, The surge protection device according to claim 1, comprising a housing for housing the aforementioned substrate.

3. A first port connected to the aforementioned splitter, into which data signals and power are input from the aforementioned PoE-compatible communication line, The surge protection device according to claim 2, further comprising a second port connected to the injector and outputting data signals and power to the PoE-compatible communication line.

4. In a plan view, the aforementioned substrate is It is defined as a pattern region where a pattern is formed and a patternless region where no pattern is formed. The surge protection device according to claim 2, wherein the first surge protection element is provided across the area without the pattern.

5. The surge protection device according to claim 4, wherein a slit is provided in the area where the pattern does not overlap with the first surge protection element.

6. The substrate is rectangular in shape. The surge protection device according to claim 2, wherein the first surge protection element is provided on one side along the long side of the rectangle, and the second surge protection element is provided on the other side along the long side of the rectangle.

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