CN2694583Y - A lightning protection circuit - Google Patents
A lightning protection circuit Download PDFInfo
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- CN2694583Y CN2694583Y CN 200320103845 CN200320103845U CN2694583Y CN 2694583 Y CN2694583 Y CN 2694583Y CN 200320103845 CN200320103845 CN 200320103845 CN 200320103845 U CN200320103845 U CN 200320103845U CN 2694583 Y CN2694583 Y CN 2694583Y
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Abstract
The utility model provides a lightning protection circuit, compising a signal interface used for receiving or sending the receiving signals or the sending signals required by the device; at least a group of balanced signal connecting lines used for leading in or leading out the signals from the device; at least a ground strip, the edges of the ground strip are respectively equidistant with the balanced signal connecting lines, which is used for discharging the overvoltage energy generated between the balanced signal connecting lines and the ground when the outside thunder and lightning is applied to the signal interface. Making use of the utility model to design the lightning protection circuit has no need of considering the signal rate, the signal level and the direct current biasing level, the high lightning protection grade can be realized on the base of not increasing the devices and the costs, and the high density and the low cost design of the electron and communication products can turn into possibility.
Description
Technical field
The utility model relates to communication technical field, is specifically related to a kind of lightning protection circuit.
Background technology
At present, along with electronics, development of Communication Technique, communication equipment is complicated day by day, and the status of communication apparatus and importance also improve day by day.Electronics, the high integration of communication chip and the high density of circuit design can cause the antijamming capability of chip, circuit or equipment to become fragile, stability, reliability variation on the one hand; On the other hand because the raising of communication apparatus importance and status in order to ensure user's demand, requires the necessary reliable and stable operation of equipment.The contradiction of these two aspects has determined that guard technology is urgent in the importance and the development of electronics, communications industry.
Usually thunder and lightning is that main in the external interference also is the most severe interference source, the relative power port of the signal port of communication equipment then is the signal transmission rate height, kind is many, the port that antijamming capability is relatively poor relatively is so the signal port shocking preventing technology becomes an important directions of existing electronics, communications industry research.
Using the most general scheme at present in the design is to adopt the method at signal port reload signal SPD (lightning protection device) to realize lightning protection.The SPD principle as shown in Figure 1, three utmost point discharge tubes among the figure can replace with two two utmost point discharge tubes, resistance can replace with inductance.This circuit is made up of discharge tube G1, silicon protection diode D (normally transition diode), resistance R (or inductance L), is actually the two poles of the earth lightning protection circuit.First order discharge tube G1 is used for the bypass big electric current of transient state of releasing, and discharge tube has the characteristics of big through-current capability and higher residual voltage; Second level silicon protection diode D is used for the clamp pressure limiting, and the electronic equipment or the components and parts of protection back, device D have the characteristics of low through-flow, fast-response, low residual voltage usually; The first order often is called thick protection, and the second level often is called thin protection.Resistance between these the two poles of the earth or inductance are used to improve the operating characteristics of discharge tube G1 and promote the two poles of the earth protective feature to cooperate.After the temporary overvoltage ripple arrived lightning protection circuit along the signal line transmission, because discharge tube G1 has higher discharge voltage and long response time, it can not very fast discharge conducting.Before discharge tube G1 does not discharge as yet; silicon protection diode D will at first puncture; and flow through transient current; increase along with this branch road transient current; also correspondingly increase between resistance between these the two poles of the earth or the pressure drop on the inductance; this pressure drop is added on discharge tube G1 two ends, impels discharge tube G1 to move discharge as early as possible.After discharge tube G1 discharge, the passage that it will provide a bypass to release the big electric current of transient state, it also can play over-voltage simultaneously, and implements the protection to resistance (or inductance) and silicon protection diode D.This circuit through-current capability is strong, and residual voltage is low, can realize the high-magnitude lightning protection.But also there is following shortcoming in this circuit:
(1) this circuit adopts the secondary lightning protection, has used multiple device, the cost height.
(2) the most device of this circuit need be selected plug-in unit, and volume is big, to the multiple signals jaws equipment (for example: the switch of 48 road network mouths), can't use this design to realize the design of small size, high-density circuit.
(3) this circuit is owing to used the secondary lightning protection circuit; usually first class of protection circuit G has the parasitic capacitance of 1-5pf; and the second class protection circuit of " fast recovery diode bridge+protection diode " has the parasitic capacitance of 8-20pf usually; these parasitic capacitances can have influence on the rising edge and the trailing edge of high speed signal; influence signal quality and transmission range; so this circuit for the lightning Protection Design of part high speed signal and very high-speed signals with inapplicable, the lightning Protection Design of 100M/1000M network interface for example.
(4) between this circuit two-stage lightning protection circuit decoupling component resistance or inductance are arranged, this resistance or inductance are connected in the signal circuit, and signal is had decay, influences signal.
Usually, for the balanced signal mouth, can also utilize the isolation characteristic of the isolating transformer of signal port own to carry out lightning Protection Design, its principle as shown in Figure 2.This design mainly based on: for balanced line, external interference mainly is a common mode disturbances; And differential mode interference to external world, chip itself can bear; So restrain common mode disturbances, just can realize the signal port lightning protection.Utilize the isolation characteristic of isolating transformer, common mode disturbance voltage is isolated in the interface side of transformer, and the transformer side chip does not have common mode disturbances, so just realizes suppressing common mode disturbances.Because the holding wire of the transformer interface side of this lightning protection circuit is when surge arrives, be to be in high pressure conditions, so select withstand voltage enough strong isolating transformer during circuit design, and in PCB layout and structural design, holding wire and other holding wires, ground wire and the power supply of noting the transformer interface side have enough insulation distances, prevent the insulation breakdown discharge and cause common mode disturbances to be transformed into differential mode interference or directly damage late-class circuit.But this circuit is primarily aimed at the balanced line port lightning Protection Design of isolating transformer, the isolating transformer voltage endurance capability is required than higher, and the lower grade of lightning protection that realizes; Simultaneously, this circuit design than higher, needs strict control insulation distance to the PCB layout designing requirement, is difficult to realize design purpose for the High Density Interface circuit, and is can realization property not strong.
The utility model content
The purpose of this utility model is the above-mentioned shortcoming that overcomes prior art, and a kind of lightning protection circuit is provided, and is used for device signal mouth front end discharge lightning protection, it is characterized in that described circuit comprises:
Signaling interface is used to receive or the signal of required reception of transmitting apparatus or transmission;
At least one group of balanced signal line is used for described signal is imported or derive described equipment;
At least one ground strip, its edge are equidistant with described balanced signal line respectively, the overvoltage energy that is used to release and produces between described balanced signal line and ground when being applied to described signaling interface because of extraneous thunder and lightning reason.
Alternatively, described balanced signal line is one section metal wire on the pcb board (printed substrate), described ground strip be on the pcb board with certain section equidistant metal curve or the metal broken line of described balanced signal line.
Alternatively, described circuit also comprises: isolating transformer, be coupled to described signaling interface and described signal access device by described balanced signal line respectively, be applied to common mode residual voltage on the late-class circuit when being used for further isolated preceding-terminal discharging gap bleed off overvoltage energy.
Preferably, described ground strip comprises: at least one ground through hole, and near described balanced signal line.
Alternatively, described ground strip also comprises: described device housings, and described equipment veneer hold-down screw, described signaling interface connects shell, ground connection fixed terminal, device ground pin pad, PCB ground wire, the metal part of PCB stratum and described device housings ground short circuit.
Alternatively, described balanced signal line comprises: the signal link pad at described signaling interface place, the signal link PCB layout, through hole on the described balanced signal line, device pin pad with the direct-connected short circuit of described balanced signal line, the centre cap that described isolating transformer primary coil is drawn, described centre tap circuit and described balanced signal line direct current short circuit part.
Preferably, described equidistantly distributing at the other ground strip of described balanced signal line is set between the 6mil to 40mil according to the required different discharge voltages of equipment with the distance of described balanced signal line.
Preferably, described circuit also comprises: discharge tube, one end is coupled to described balanced signal line, the other end is coupled to described ground strip, be used for forming the backup design with the front end discharging gap, when bleed off is applied to described signaling interface because of extraneous thunder and lightning reason, the overvoltage energy that between described balanced signal line and ground, produces.
Alternatively, described discharge tube comprises: electric capacity or resistance, or the serial or parallel connection circuit of electric capacity and resistance composition.
Utilize the utility model to carry out the lightning protection circuit design, do not need to consider signal rate, signal level and DC biased level, can on the basis that does not increase device, cost, realize high lightning protection grade making the densification of electronics, communication products, low cost be designed to possibility.
Description of drawings
Fig. 1 is prior art signal port SPD circuit theory diagrams;
Fig. 2 is that prior art utilizes isolating transformer to isolate the principle sketch that common mode disturbances realizes lightning protection;
Fig. 3 is a design PCB layout schematic diagram in the utility model signal port front end discharge lightning protection circuit;
Fig. 4 is the equivalent schematic diagram of embodiment signal port front end discharge lightning protection circuit of the present utility model shown in Figure 3;
Fig. 5 is a design PCB layout schematic diagram when adopting single ground strip in the utility model signal port front end discharge lightning protection circuit;
Fig. 6 is the equivalent schematic diagram of embodiment signal port front end discharge lightning protection circuit of the present utility model shown in Figure 5;
Fig. 7 is the explanation PCB schematic diagram of ground strip and holding wire in the utility model signal port front end discharge lightning protection circuit;
Fig. 8 be among the embodiment of the present utility model on the front end discharge protection circuit parallel discharge pipe to form the PCB layout schematic diagram of backup lightning protection circuit.
Embodiment
For those of ordinary skills being understood and implementing the utility model, now depicted in greater detail embodiment in conjunction with the accompanying drawings can more easily understand the purpose of this utility model and technical scheme and effect of the present utility model by these embodiment those skilled in the art.
The utility model has utilized the nonlinear characteristic protection philosophy of protection device discharging gap; in balanced line signal port lightning Protection Design, do not increase protection device; in the PCB design process, utilize PCB itself to form a PCB layout circuit with discharging gap characteristic; thereby realization lightning Protection Design; as shown in Figure 3, its equivalent schematic diagram is referring to Fig. 4.For the balanced line signal port, being the port that carries out the balanced signal communication in the port, mainly is common mode disturbances owing to respond to the caused interference of thunder, i.e. the holding wire of Chan Shenging and interference voltage between the ground or electric current, the common mode disturbances so draw up just can realize the signal port lightning protection.With reference to Fig. 3 and embodiment signal port front end discharge lightning protection circuit design PCB layout schematic diagram of the present utility model and equivalent schematic diagram shown in Figure 4, in this signal port front end discharge lightning protection circuit, the PCB veneer inserts by signaling interface 31 or required reception of transmitting apparatus or transmission signal, by balanced signal link group TX+ and TX-the equipment desired signal is imported or derives this equipment then, at anomaly weighing apparatus signal link group TX+ and equidistant position, TX-both sides one group of ground strip is arranged, in the present embodiment, be ground through hole 34 and ground through hole 35, the overvoltage energy that is used to release and between described balanced signal line and ground, produces when being applied to described signaling interface because of extraneous thunder and lightning reason.In order further to isolate common mode disturbances, it is the interference between holding wire and the ground, by balanced signal link group TX+ and TX-required acceptance or send before signal imports or derive this equipment related chip with equipment, also will be through an isolating transformer 32, remaining common mode disturbances is isolated in the interface side of isolating transformer behind the overvoltage energy that produces between balanced signal line that will cause because of extraneous thunder and lightning owing to releasing by ground through hole 34 and ground through hole 35 and the ground.
The principle of isolating transformer is that difference mode signal produces electric current on lead, and common-mode signal is a two-wire common electric voltage over the ground, can online generation electric current.Owing to have only differential mode may produce electric current,, thereby reach the purpose of coupled transfer so difference mode signal can be coupled to transformer secondary output; Common mode then is to reach the back level.So promptly reached the purpose of isolating.For example: two-wire voltage is respectively 1050V and 1000V, and differential mode voltage is exactly 50V so, and common-mode voltage is exactly 1025V, supposes it is 1: 1 transformer, and the voltage between lines that is transferred to the back level is exactly 50V, and two-wire does not just have voltage over the ground, but the situation of a suspension; May be exactly a line be 0V, a line is 50V.
In the utility model, by near signaling interface, on the other cloth of signal PCB layout through hole, control every holding wire and the distance of through hole be consistent.Usually PCB layout can be selected according to different discharge voltage design conditions to the distance between the through hole; usually be controlled between the 6mil-40mil; formed the front end discharge protection circuit of the protection philosophy of a similar discharging gap like this between signal PCB layout and the ground through hole; every line forms one " discharging gap " over the ground, and discharging gap parameter unanimity.During normal condition, the signal normal transmission is because parasitic capacitance is very little between signal PCB layout and the ground through hole, so to signal, even high speed transmission of signals is without any influence; When extraneous common mode overvoltage is applied to signal port; be that a transient overvoltage is arranged between holding wire and the ground,, will form the discharge of front end insulation breakdown because command range is closer between signal PCB layout and the ground through hole; this overvoltage energy of releasing, thus late-class circuit protected effectively.Be consistent by the distance between control balanced signal PCB line and the ground through hole, it is inconsistent can not form the front end discharge, causes the common mode overvoltage to convert the differential mode overvoltage to and damages late-class circuit.
In design of the present utility model, can also adopt single ground strip to form front end discharge lightning protection circuit.Equally, utilize PCB itself to form the PCB layout circuit with discharging gap characteristic in the PCB design process, thereby realize lightning Protection Design, as shown in Figure 5, its equivalent schematic diagram is referring to Fig. 6.Design PCB layout schematic diagram and equivalent schematic diagram when adopting single ground strip in Fig. 5 and the embodiment signal port front end discharge lightning protection circuit of the present utility model shown in Figure 6, in this signal port front end discharge lightning protection circuit, the PCB veneer is by the required reception of signaling interface 31 access devices or send signal, by balanced signal link group TX+ and TX-the equipment desired signal is imported or derives this equipment then, there is a ground strip equidistant position in the middle of anomaly weighing apparatus signal link group TX+ and TX-, in the present embodiment, be ground through hole 50, being used to release is applied to the overvoltage energy that produces on the described signaling interface because of extraneous thunder and lightning reason between described balanced signal line and ground.Equally, in order further to isolate common mode disturbances, it is the interference between holding wire and the ground, before the equipment desired signal being imported this equipment related chip pin by balanced signal link group TX+ and TX-, also will be through an isolating transformer 32, being isolated in the interface side of isolating transformer by release remaining common mode disturbances behind the overvoltage energy that produces between the balanced signal line that causes because of extraneous thunder and lightning and the ground of ground through hole 50.
In design of the present utility model is realized; can make full use of the structure that balanced signal mouth circuit itself exists; make the circuit devcie on the pcb board behind signal input interface, form a front end discharge protection circuit; can be implemented in signal port is added superpotential the time; holding wire is front end discharge simultaneously over the ground; bleed off overvoltage energy, the protection late-class circuit.With reference to Fig. 7, Fig. 7 is the explanation PCB schematic diagram of ground strip and holding wire in the utility model signal port front end discharge lightning protection circuit.Each label shown in the figure represents that implication is as follows:
The holding wire pad of 1 expression interface interface device
2 expression signal PCB layout
The through hole of 3 expression signal line passes
4 expression device pin pads
5 expression signal center tap circuit parts
6 indication equipment shells
7 expression PCB earthing screws
8 expression interface connector shells
9 expression connector dead earth terminals
10 expression ground PCB layout
11 expression stratum
12 expression ground pads
13 expression ground through holes
Wherein, the balanced signal line comprises: signaling interface place interface device holding wire pad, the signal PCB layout, through hole on the holding wire, with the device pin pad of the direct-connected short circuit of holding wire, and the part of all and holding wire direct current short circuit such as Signal Spacing transformer primary coil centre cap of drawing and centre tap circuit; Ground comprises: device housings, and PCB veneer hold-down screw, interface connector shell and ground connection fixed terminal, device ground pin pad, the ground through hole, the ground PCB layout, ground PCB layer waits the part of all and shell ground short circuit.
In the wiring of PCB veneer, with above-mentioned balanced signal line required in the veneer with above-mentioned carry out any combination in twos, according to distance (being generally 6-40mil) between different selected balanced signal lines of discharge voltage design and the ground, and guarantee that distance equates consistent between the holding wire of same port and the ground, can realize the design of front end discharge lightning protection circuit.
In order to make above-mentioned front end discharge lightning protection circuit play better lightning protection effect; can also be between described balanced signal line and described ground strip the device of parallel discharge pipe and similar discharge tube; be used for forming the backup design with the front end discharging gap; when bleed off is applied to signal port because of extraneous thunder and lightning reason, the overvoltage energy that between line equalize signal and ground, produces.Referring to Fig. 8, Fig. 8 is the PCB layout schematic diagram that the parallel discharge pipe backs up lightning protection circuit with formation on above-mentioned front end discharge protection circuit.Discharge tube can adopt electric capacity or resistance, or the serial or parallel connection circuit of electric capacity and resistance composition.Guarantee that the device in parallel that increases does not influence the signal normal transmission, but insulation breakdown can take place when signal port adds overvoltage, thus bleed off overvoltage energy protection late-class circuit.
Though described the utility model by embodiment, those of ordinary skills know, the utility model has many distortion and variation and does not break away from spirit of the present utility model, wishes that appended claim comprises these distortion and variation and do not break away from spirit of the present utility model.
Claims (9)
1, a kind of lightning protection circuit is used for device signal mouth front end discharge lightning protection, it is characterized in that described circuit comprises:
Signaling interface is used to receive or the signal of required reception of transmitting apparatus or transmission;
At least one group of balanced signal line is used for described signal is imported or derive described equipment;
At least one ground strip, its edge are equidistant with described balanced signal line respectively, the overvoltage energy that is used to release and produces between described balanced signal line and ground when being applied to described signaling interface because of extraneous thunder and lightning reason.
2, lightning protection circuit as claimed in claim 1, it is characterized in that, described balanced signal line is one section metal wire on the pcb board (printed substrate), described ground strip be on the pcb board with certain section equidistant metal curve or the metal broken line of described balanced signal line.
3, lightning protection circuit as claimed in claim 1 or 2, it is characterized in that, described circuit also comprises: isolating transformer, be coupled to described signaling interface and described signal access device by described balanced signal line respectively, be applied to common mode residual voltage on the late-class circuit when being used for further isolated preceding-terminal discharging gap bleed off overvoltage energy.
4, lightning protection circuit as claimed in claim 1 or 2 is characterized in that, described ground strip comprises: at least one ground through hole, and near described balanced signal line.
5, lightning protection circuit as claimed in claim 1 or 2, it is characterized in that, described ground strip also comprises: described device housings, described equipment veneer hold-down screw, described signaling interface connects shell, ground connection fixed terminal, device ground pin pad, the PCB ground wire, the metal part of PCB stratum and described device housings ground short circuit.
6, lightning protection circuit as claimed in claim 1 or 2, it is characterized in that, described balanced signal line comprises: the signal link pad at described signaling interface place, the signal link PCB layout, through hole on the described balanced signal line, with the device pin pad of the direct-connected short circuit of described balanced signal line, the centre cap that described isolating transformer primary coil is drawn, described centre tap circuit and described balanced signal line direct current short circuit part.
7, lightning protection circuit as claimed in claim 1 or 2 is characterized in that, described equidistantly distributing at the other ground strip of described balanced signal line is set between the 6mil to 40mil according to the required different discharge voltages of equipment with the distance of described balanced signal line.
8, lightning protection circuit as claimed in claim 1 or 2, it is characterized in that, described circuit also comprises: discharge tube, one end is coupled to described balanced signal line, the other end is coupled to described ground strip, be used for forming the backup design with the front end discharging gap, when bleed off is applied to described signaling interface because of extraneous thunder and lightning reason, the overvoltage energy that between described balanced signal line and ground, produces.
9, lightning protection circuit as claimed in claim 8 is characterized in that, described discharge tube comprises: electric capacity or resistance, or the serial or parallel connection circuit of electric capacity and resistance composition.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200320103845 CN2694583Y (en) | 2003-10-21 | 2003-10-21 | A lightning protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200320103845 CN2694583Y (en) | 2003-10-21 | 2003-10-21 | A lightning protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2694583Y true CN2694583Y (en) | 2005-04-20 |
Family
ID=34761816
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200320103845 Expired - Fee Related CN2694583Y (en) | 2003-10-21 | 2003-10-21 | A lightning protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2694583Y (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103259255A (en) * | 2012-02-20 | 2013-08-21 | 联想(北京)有限公司 | Lightening protection circuit of network interface |
| CN104578028A (en) * | 2014-11-28 | 2015-04-29 | 上海航空电器有限公司 | Lightning indirect effect protective structure of airborne equipment |
| CN114648867A (en) * | 2022-02-18 | 2022-06-21 | 广东逸动科技有限公司 | Remote control signal processing system of propeller, propeller and water vehicle |
-
2003
- 2003-10-21 CN CN 200320103845 patent/CN2694583Y/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103259255A (en) * | 2012-02-20 | 2013-08-21 | 联想(北京)有限公司 | Lightening protection circuit of network interface |
| CN103259255B (en) * | 2012-02-20 | 2016-03-30 | 联想(北京)有限公司 | A kind of lightning protection circuit of network interface |
| CN104578028A (en) * | 2014-11-28 | 2015-04-29 | 上海航空电器有限公司 | Lightning indirect effect protective structure of airborne equipment |
| CN104578028B (en) * | 2014-11-28 | 2019-03-05 | 上海航空电器有限公司 | A kind of lightning indirect effect protection structure of airborne equipment |
| CN114648867A (en) * | 2022-02-18 | 2022-06-21 | 广东逸动科技有限公司 | Remote control signal processing system of propeller, propeller and water vehicle |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20050420 Termination date: 20111021 |