CN100414803C - Lightning protection method and device for Ethernet port - Google Patents

Abstract

The invention discloses a lightning protection method and device for an Ethernet port, wherein the method is: providing an instantaneous high-voltage current discharge path between the differential lines of a differential line pair, and the current discharge is provided by a gas discharge tube, which is located at the front of the protection circuit stage; the high voltage generated between the differential lines due to lightning and high-voltage static electricity is released by the instantaneous high-voltage current discharge path; the rear stage of the differential circuit uses varistors and TVS tubes for voltage clamping; The residual voltage is clamped to a lower voltage value by the varistor and TVS tube to protect the subsequent circuit. The lightning protection device includes: a receiving differential line pair, a transmitting differential line pair, and an instantaneous high-voltage current discharge circuit; the instantaneous high-voltage current discharge circuit is connected to the two differential lines of the receiving differential line pair and the transmitting differential line pair between lines. The invention is mainly used for Ethernet lightning protection, and has the characteristics of high safety, low cost and flexible networking.

Description

Lightning protection method and device for Ethernet port

technical field

The invention relates to a lightning protection device, in particular to a lightning protection method and device for an Ethernet port.

Background technique

With the vigorous construction of domestic broadband metropolitan area networks, more and more Ethernet switches are used as user access devices in enterprise networks and broadband communities. With the expansion and deterioration of the application environment of switches, especially in corridors, operators need to improve the security performance of Ethernet ports and increase the lightning protection capabilities of ports to meet the needs of reliable long-distance travel of equipment.

The Ethernet port with lightning protection function can resist lightning strikes and static electricity, support even harsher networking environments, and effectively improve the security of network equipment and other electrical equipment. Therefore, it is more and more popular in enterprise network and broadband networking applications. more attention.

Currently, there is no other effective lightning protection method for Ethernet ports on the market. In specific networking, Ethernet equipment can only be protected to a certain extent by deep burial and other construction methods against natural disasters such as lightning strikes and high-voltage static electricity. The disadvantages of this approach are:

1. Poor security. The method of deeply buried network cables generally only protects the uplink port or other important Ethernet user interfaces, and the network cables of other interfaces are still open, so the danger of lightning strikes and static electricity still exists.

2. High cost. General construction methods all have high manpower and material costs, and often extend the construction period.

Contents of the invention

The purpose of the present invention is to provide a lightning protection method and device for Ethernet, so as to improve the security of the network, reduce the cost and the like.

The method of the present invention is:

Provide an instantaneous high-voltage current discharge path between the differential lines of the differential line pair; wherein, the current discharge path adopts a two-level protection method;

The high voltage generated between the differential lines due to lightning and high-voltage static electricity is released through the instantaneous high-voltage current discharge path.

According to the above method: the two-stage protection method refers to: connecting the front-stage protection device and the rear-stage protection device between the front-stage differential line and the rear-stage differential line respectively, and connecting the front-stage protection device and the rear-stage protection device series impedance device.

The pre-stage protection device is an air discharge tube connected between the pre-stage differential lines, the post-stage protection device is a voltage clamping transient suppression diode connected between the post-stage differential lines, and the impedance device is a pressure-sensitive resistance.

The current discharge path is set outside the Ethernet port or at the back stage of the Ethernet port.

Lightning protection device of the present invention comprises:

Receive differential line pair, transmit differential line pair and current discharge circuit for instantaneous high voltage; among them,

The instantaneous high-voltage current discharge circuit includes: a front-stage protection device connected to the front-stage differential line, a rear-stage protection device connected to the rear-stage differential line, and a series connection between the front-stage protection device and the rear-stage protection device. impedance devices.

According to the above lightning protection device: the preceding protection device is an air discharge tube, the subsequent protection device is a voltage clamping transient suppression diode, and the impedance device is a piezoresistor.

Both ends of the differential line pair are electrically connected to a plug or a socket respectively, so as to facilitate connection with other devices.

Effect of the present invention:

1. High security: The built-in or external lightning protection module design is adopted on the Ethernet device, which can reliably reduce the probability of lightning damage to the device. At the same time, it can effectively avoid the high-voltage danger caused by other electrical equipment, and avoid the high-voltage danger caused by other electrical equipment.

2. Low cost: adopting the present invention can reduce engineering construction such as trenching and lower the cost of networking.

3. Flexible networking: With the present invention, Ethernet devices can be equipped with lightning protection modules or circuits according to actual needs, adapting to complex networking environments. In addition, it is convenient for network management and maintenance.

Description of drawings

Fig. 1 is a schematic circuit diagram of the present invention;

Fig. 2 is the circuit schematic diagram of another structure of the present invention,

Fig. 3 is a schematic circuit diagram of another structure of the present invention.

Fig. 4 is the networking diagram outside the Ethernet equipment of the lightning protection device of the present invention;

Fig. 5 is a network diagram of the lightning protection device of the present invention inside the Ethernet device.

Detailed ways

The present invention provides an instantaneous high-voltage current discharge path between the differential lines of the Ethernet differential line pair. When a high voltage is generated between the differential lines in the Ethernet due to lightning and high-voltage static electricity, the instantaneous high-voltage current discharge path Release it to prevent lightning or high-voltage static electricity from entering the Ethernet device and damaging circuits and devices.

Referring to FIG. 1 , voltage-clamping transient suppression diodes (Transient Voltage Suppressor, TVS for short) VD1 and VD2 are respectively connected between differential lines rx ⁺ , rx ⁻ and differential lines tx ⁺ , tx ⁻ . TVS tubes VD1 and VD2 are integrated in one tube, and its model is SLVU2_8.4. Two pairs of connecting sockets or plugs for differential wire pairs to facilitate connection with other equipment. The TVS tube is a voltage limiting protection device, which uses the nonlinear characteristics of the device to clamp the overvoltage to a lower voltage value to protect the subsequent circuit. When instantaneous high voltage is generated between the differential lines due to lightning, etc., the TVS tube clamps the high voltage, and this structure provides single-stage protection for the 10/100BASE-T Ethernet port.

Referring to Figure 2, the structure shown in the figure uses an air discharge tube as the high voltage release path, and the model of the air discharge tube is 3r097cxa_2. The air discharge tube is a switch-type protective device, and its working principle is gas discharge. When the voltage between the two poles is large enough, the gap between the poles will be broken down by discharge, and the original insulating state will be transformed into a conductive state, similar to a short circuit. In the conductive state, the voltage maintained between the two poles is very low, generally 20-50V, so it can protect the subsequent circuit. This structure mainly discharges high voltage caused by static electricity or the like.

Referring to Figure 3, the structure shown in the diagram uses a voltage-clamping transient suppression diode (Transient Voltage Suppressor, TVS for short) and an air discharge tube as the instantaneous high-voltage current discharge path and voltage clamping circuit, for 10/100BASE-T Ethernet Ports are protected in two levels. Air discharge tubes G1 and G2 and TVS tubes VD1 and VD2 are respectively connected between differential lines rx ⁺ , rx ^- and differential lines tx ⁺ , tx ^- . The model of the TVS tube is SLVU2_8.4, and the model of the air discharge tube is 3r097cxa_2. 2W high-power piezoresistors R1, R2, R3 and R4 are connected between the TVS tube and the air discharge tube.

The varistor is a voltage limiting protection device. Utilizing the nonlinear characteristics of the varistor, when an overvoltage occurs between the two poles of the varistor, the varistor can clamp the voltage to a relatively fixed voltage value.

When a high voltage is generated between the differential lines, the voltage between the two poles of the air discharge tube is large enough, and the gap between the poles will break down the discharge, and the original insulating state will be transformed into a conductive state, similar to a short circuit. The voltage maintained between the two poles in the conductive state is very low, generally 20-50V. The varistor and TVS tube clamp the overvoltage to a lower voltage value, so as to realize the protection of the subsequent circuit.

Figure 4 is a networking diagram in which the lightning protection module is placed outside the Ethernet device. The entire lightning protection module is connected outside the Ethernet port, that is, between the network port connector RJ45 and the user equipment PC, to form a separate lightning protection device.

Figure 5 shows that the lightning protection module is installed at the back stage of the port, that is, between the network port connector RJ45 and the network port transformer, and becomes a part of the Ethernet device.

The lightning protection device in this embodiment mainly protects the receiving and sending differential line pairs of the 10/100BASE-T Ethernet port. By adopting the method or device described in the invention, the port of the Ethernet device can resist the instantaneous current of 10KA at most, and at the same time, the circuit is stable and reliable, which can completely meet the networking requirements of the Ethernet device.

Claims (7)

1. A lightning protection method for an Ethernet port is characterized in that:

providing a current leakage path of instantaneous high voltage between the differential lines of the differential line pair; the current leakage path adopts a two-stage protection mode; the two-stage protection mode is as follows: a front stage protection device and a rear stage protection device are respectively connected between the front stage differential line and the rear stage differential line, and an impedance device is connected in series between the front stage protection device and the rear stage protection device; the high voltage generated by lightning and high-voltage static electricity between the differential lines is released by the instantaneous high-voltage current leakage path.

2. The method of claim 1, wherein the preceding stage protection device is an air discharge tube connected between preceding stage differential lines, the subsequent stage protection device is a voltage clamp type transient suppression diode connected between subsequent stage differential lines, and the impedance device is a varistor.

3. Method according to one of claims 1 to 2, characterized in that the current bleeding path is arranged outside the ethernet port.

4. The method according to any one of claims 1 to 2, wherein the current bleeding path is provided at a stage subsequent to the ethernet port, and is a part of an ethernet device.

5. A lightning protection device for an ethernet port, comprising: the current bleeder circuit receives the differential line pair, sends the differential line pair and instantaneous high voltage; wherein,

the current bleeder circuit of the instantaneous high voltage includes: the protection circuit includes a preceding stage protection device connected to a preceding stage differential line, a succeeding stage protection device connected to a succeeding stage differential line, and an impedance device connected in series between the preceding stage protection device and the succeeding stage protection device.

6. The lightning protection device according to claim 5, wherein the front stage protection device is an air discharge tube, the rear stage protection device is a voltage clamping transient suppression diode, and the impedance device is a varistor.

7. The lightning protection device according to any one of claims 5 to 6, wherein both ends of the differential line pair are electrically connected to a plug or a socket, respectively, so as to facilitate connection with other equipment.

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