Utility model content
The purpose of this utility model is that one has superpower lightning protection capability, comprises three grades of lightning-protection systems.Be intended to solve requirement of shelter high, the problems such as demand on signal quality is high.
For reaching this object, the utility model by the following technical solutions:
Based on three grades of lightning-protection modules of network interface protection, comprise input side RJ45 interface, isolating transformer and outlet side RJ45 interface, is characterized in that: comprise three grades of lightning protection,
First order lightning-protection system is positioned at input side RJ45 interface side, comprises four gas discharge tubes, has 4 pairs of differential data line at input side RJ45, a described gas discharge tube in parallel between every pair of data lines, the crura intermedium ground connection of described gas discharge tube;
Second level lightning-protection system is positioned at isolating transformer, draws single line from the centre cap of each winding of described isolating transformer, and 4 lines of drawing connect a piezo-resistance respectively to ground, and four piezo-resistances form second level lightning-protection system;
Third level lightning-protection system A is also positioned at isolating transformer, the line of drawing from the centre cap of each winding of described isolating transformer connects a bipolarity transient voltage killer tube respectively to ground, and four bipolarity transient voltage killer tubes form the 3rd pole lightning-protection system A.
Preferably, also comprise third level lightning-protection system B, described third level lightning-protection system B is positioned at isolating transformer, divide 4 protection groups, described protection group is connected in parallel between 4 pairs of differential data line of isolating transformer secondary side extraction respectively, and each protection group comprises a rectifier bridge and the unidirectional TVS pipe with rectifier bridge parallel connection, and each described rectifier bridge is by two Diode series, four diodes be connected in parallel to each other again formed, and described differential data line is between two diodes of series connection.
Preferably, be connected to network isolation transformer primary side in 8 data lines of input side RJ45 by 8 decoupling resistances, described decoupling resistance is as the isolation of first order lightning protection and second level lightning protection.
Preferably, for third level lightning protection A, the line of drawing at described centre cap is first connected a decoupling inductance, more described bipolarity transient voltage killer tube of connecting is to ground.
Preferably, be used for POE from going between described isolation inductance and described bipolarity transient voltage killer tube to power.
Preferably, the described gas discharge tube puncture voltage of first order lightning protection is between 200-250V, and through-current capacity is greater than 2000A, and clamp voltage is within 20V.
Preferably, the clamp voltage of the described piezo-resistance of second level lightning protection is between 120V-140V, and through-current capacity is greater than 500A.
Preferably, described decoupling resistance is the chromatic circle resistance in 2.2 Europe, more than power 3W, and the inductance value of described decoupling inductance is greater than 220uH.
Preferably, the described bipolarity transient voltage killer tube puncture voltage in described third level lightning-protection system A is greater than 56V, and clamp voltage is less than 70V.
Preferably, about puncture voltage 5V, clamp voltage is no more than 20V in picosecond the described unidirectional TVS pipe response time of third level lightning protection B.
To sum up, the utility model combines the advantage of three kinds of different lightning-protection systems, builds three grades of lightning-protection systems, increases decoupling resistance and decoupling inductance effectively to isolate between different lightning-protection systems simultaneously.The advantages such as the utility model has high, the manipulative TVS pipe junction capacitance of degree of protection, the response time of each element of unattenuated signal, reasonable utilization and through-current capacity, composition multistage protection.
Embodiment
Below in conjunction with drawings and Examples, the utility model is described in further detail.Be understandable that, specific embodiment described herein only for explaining the utility model, but not to restriction of the present utility model.It also should be noted that, for convenience of description, illustrate only the part relevant to the utility model in accompanying drawing but not entire infrastructure.
See Fig. 1, disclose the three grades of lightning-protection modules of powering based on POE according to the utility model specific embodiment.It comprises input side RJ45 interface 1, isolating transformer 2 and outlet side RJ45 interface 3, first order lightning-protection system is positioned at input side RJ45 interface side, comprise four gas discharge tubes G1, G2, G3 and G4, at input side RJ45, there are 4 pairs of differential data line, a gas discharge tube in parallel between every pair of data lines, the crura intermedium ground connection of described gas discharge tube;
Second level lightning-protection system is positioned at isolating transformer, single line is drawn from the centre cap of each winding of described isolating transformer, 4 lines drawing connect a piezo-resistance respectively to ground, and namely described four piezo-resistance RV1, RV2, RV3 and RV4 form second level lightning-protection system;
Third level lightning-protection system A is also positioned at isolating transformer, the line of drawing from the centre cap of each winding of described isolating transformer connects a bipolarity transient voltage killer tube respectively to ground, and four bipolarity transient voltage killer tube TVS1 ~ TVS4 form the 3rd pole lightning-protection system A;
Third level lightning-protection system B is positioned at isolating transformer, divide 4 protection groups, described 4 protection groups are connected in parallel between 4 pairs of differential data line of isolating transformer secondary side extraction respectively, each protection group comprises a rectifier bridge and the unidirectional TVS pipe with rectifier bridge parallel connection, each described rectifier bridge is by two Diode series, four diodes be connected in parallel to each other again formed, and described differential data line is between two diodes of series connection.See Fig. 1, D1 and D3 series connection, D2 and D4 connects, TVS5 in parallel again after composition rectifier bridge, and a differential data line is between D1 and D3, and an other differential data line is between D2 and D4; Similar D5 ~ D8 forms a rectifier bridge, then TVS6 in parallel; D9 ~ D12 forms a rectifier bridge, then TVS7 in parallel; D13 ~ D16 forms a rectifier bridge, then TVS8 in parallel; Above-mentioned diode D1 ~ D16 and TVS5 ~ TVS8 is composition third level lightning-protection system B just.
Three grades of lightning-protection systems of the present utility model, rationally form according to the speed of various lightning protection component response time and the not equivalent properties of surge capacity of releasing, lightning protection grade is high, lightning protection good reliability.
First order lightning protection is gas discharge tube G1 ~ G4, this grade of lightning protection both anti-differential mode also anti-common modes.When differential mode surge attacks, there is surge voltage at gas discharge tube G1 ~ G4 two ends, and when its surge voltage has exceeded the breakdown value of gas discharge tube, gas discharge tube can be breakdown, and surge voltage will be clamped in very low voltage threshold.When common mode surge attacks; one end and the crura intermedium of gas discharge tube G1 ~ G4 have surge voltage, and when its surge voltage has exceeded the breakdown value of gas discharge tube, gas discharge tube is breakdown; surge voltage is clamped in very low voltage threshold, thus protection late-class circuit.
Second level lightning protection is piezo-resistance RV1 ~ RV4, and this grade of lightning protection can only protect common mode surge.When common mode surge comes interim; and its voltage has exceeded the pressure sensitive voltage value of piezo-resistance; piezo-resistance starts clamper; along with the rising of surge voltage; in piezo-resistance, voltage also can raise, but after being elevated to the clamped voltage value of piezo-resistance, even if surge voltage raises again; in piezo-resistance, voltage also can not raise again, thus protection late-class circuit.
Preferably, after 8 data lines of input side RJ45 are connected to network isolation transformer primary side by 8 decoupling resistances, as the isolation of first order lightning protection and second level lightning protection.When after piezo-resistance RV1 ~ RV4 clamper; if there is no R1 ~ R8; common-mode voltage so on first order lightning protection G1 ~ G4 just can only reach the clamped voltage value of piezo-resistance RV1 ~ RV4; and the puncture voltage of gas discharge tube is higher than piezo-resistance clamp voltage; cause gas discharge tube G1 ~ G4 cannot be breakdown, do not have the effect of protection.
Third level lightning-protection system A is two-way TVS pipe TVS1 ~ TVS4, and this grade of lightning protection can only protect common mode surge.When common mode surge comes interim, and its voltage has exceeded the puncture voltage of described two-way TVS pipe, and two-way TVS pipe can by surge clamper, and along with the rising of surge voltage, on two-way TVS, voltage also can not raise again, thus protection late-class circuit.
Preferred further, between described piezo-resistance RV1 ~ RV4 and described two-way TVS pipe TVS1 ~ TVS4, there is decoupling inductance.Described decoupling inductance has two effects, and one is to play electric current inhibitory action, and two is the isolation as second level lightning protection and 3rd level lightning protection A.When surge spike is added on decoupling inductance, due to the characteristic of inductance, inverse electromotive force can be produced and suppress electric current to increase, there is pressure drop at inductance two ends simultaneously.After TVS1 ~ TVS4 is breakdown, if do not have L1 ~ L4, in piezo-resistance, voltage also can by clamper and two-way TVS pipe same level, causes piezo-resistance cannot be breakdown, does not have protective effect.
Further preferably, described third level lightning-protection system A, except protection PHY, also will protect rear level power supply.Because generally 48V DC power supply can be provided as POE power supply to rear class mainboard from isolating transformer centre cap lead-out wire.Namely see Fig. 2, the network equipment disclosed in the utility model is also applicable to POE and powers, and that is lightning-protection module disclosed in the utility model can further protect having the network equipment that POE powers.In the present embodiment, be used for POE from going between described isolation inductance and described bipolarity transient voltage killer tube to power.Specifically, after inductance L 1 ~ L4, draw four lines respectively power for POE, wherein, POE powers _ 1,2 and POE power _ 3,6 be one group and power; POE powers _ 4,5 and POE power _ 7,8 are another group power supplies.
Third level lightning-protection system B comprises diode D1 ~ D16 and unidirectional TVS pipe TVS5 ~ TVS8, and the protection of this level can only protect differential mode surge.Being on duty, it is interim to touch surge, has surge voltage between often pair of differential data line, and now TVS pipe can by voltage clamping, protection late-class circuit.But TVS pipe junction capacitance is very large, is placed between data wire and can affects signal quality.For so, it is in parallel with TVS that the utility model uses 4 diodes to form a rectifier bridge, then be parallel between data wire by rectifier bridge.Such data-signal is charged to the junction capacitance of TVS by rectifier bridge, and after being full of, junction capacitance does not have discharge path.Like this, when data-signal is low, junction capacitance is not discharged by holding wire; When data-signal is high, junction capacitance is full of already, and data-signal also can not charge to junction capacitance.So, the capacity effect of TVS will become very little very little, affects signal quality hardly.
Preferably, the described gas discharge tube puncture voltage of first order lightning protection is between 200 ~ 250V, and through-current capacity is greater than 2000A, and clamp voltage is within 20V.
Preferably, the clamp voltage of the described piezo-resistance RV1 ~ RV4 of second level lightning protection is between 120V ~ 140V, and through-current capacity is greater than 500A.
Preferably, described decoupling resistance is the chromatic circle resistance in 2.2 Europe, more than power 3W.
Preferably, described third level lightning-protection system A, except protection PHY, also will protect rear level power supply.Because generally 48V DC power supply can be provided as POE power supply to rear class mainboard from isolating transformer centre cap lead-out wire.So described two-way TVS pipe, namely described bipolarity transient voltage killer tube TVS1 ~ TVS4 is preferably puncture voltage and is greater than 56V, and clamp voltage is less than the two-way TVS pipe of 70V.
Preferably, described decoupling inductance will select large inductance value inductance, is preferably inductance value and is greater than 220uH.
Preferably, third level lightning protection B is the PHY chip in order to protect rear class, and therefore, the described unidirectional TVS pipe preferred response time, about puncture voltage 5V, clamp voltage was no more than the unidirectional TVS pipe of 20V in picosecond.
For POE lightning protection, although the through-current capability of gas discharge tube is maximum, although junction capacitance is minimum, its response time is very slow, is generally Microsecond grade.Although the response time of TVS pipe is the fastest, be generally picosecond, its through-current capability is minimum, and junction capacitance is maximum.The indices of piezo-resistance is all between the two.It is fast that good lightning-protection system must possess response simultaneously, and through-current capability is large, can not affect the features such as signal quality.To this, the utility model adopts three grades of lightning protection, and the first order is gas discharge tube, and the second level is piezo-resistance, and the third level is TVS pipe, and meet response fast, through-current capability is large, can not affect these requirements of signal quality simultaneously.
If only have one-level lightning-protection system, namely only there is gas discharge tube G1 ~ G4, also can play the protection of differential mode common mode.But the gas discharge tube response time is very slow, and lightning waveform just can rise to the high pressure of several kilovolts usually in a few microsecond, before gas discharge tube response, does not have other protection to protect late-class circuit, so probably damage late-class circuit.
If only have the 3rd pole lightning-protection system, although response is very fast, once surge energy is very large, TVS pipe cannot be born, and may be broken, thus also cannot protect late-class circuit.
In the utility model, the large through-current capacity of existing gas discharge tube, has again the quick response of TVS, and middle also have the excessive of piezo-resistance.
If differential mode surge voltage is added in the utility model, that first respond is TVS5 ~ TVS8 in third level lightning-protection system B, and TVS5 ~ TVS8 is rapidly by voltage clamping.Along with the continuation of surge voltage raises, once reach the puncture voltage of G1 ~ G4 in first order lightning-protection system, gas discharge tube G1 ~ G4 will be breakdown.Once gas discharge tube is breakdown, surge voltage will be clamped on very low voltage, and now all surge energies are all released through gas discharge tube.
If common mode surge voltage is added in the utility model, that first respond is TVS1 ~ TVS4 in third level lightning-protection system A, and TVS1 ~ TVS4 can rapidly by voltage clamping.Large inductance L 1 ~ L4 now plays metering function, prevents the too large damage TVS pipe of immediate current.Although now TVS1 ~ TVS4 clamper, due to the existence of L1 ~ L4, if surge voltage continues to strengthen, the voltage on the RV1 ~ RV4 of second level lightning-protection system can continue to increase, once reach breakdown value, RV1 ~ RV4 is again by surge voltage clamper.If surge voltage also continues to increase, due to the existence of decoupling resistance R1 ~ R8, continuation increases by the voltage on the crura intermedium of gas discharge tube and one end, once reach breakdown value, gas discharge tube G1 ~ G4 third time is by voltage clamping, and this time clamper can on very low-voltage thresholding, and all surge energies will be released through G1 ~ G4.Thus protection late-class circuit.
The advantages such as in sum, the utility model has high, the manipulative TVS pipe junction capacitance of degree of protection, the response time of each element of unattenuated signal, reasonable utilization and through-current capacity, composition multistage protection.
Above content is in conjunction with concrete preferred implementation further detailed description of the utility model; can not assert that embodiment of the present utility model is only limitted to this; for the utility model person of an ordinary skill in the technical field; without departing from the concept of the premise utility; some simple deduction or replace can also be made, all should be considered as belonging to the utility model by submitted to claims determination protection range.