A kind of dropout type lightning protection circuit
The utility model relates to Electronic Protection circuit technical field, relates in particular to a kind of dropout type lightning protection circuit.
Thunder and lightning is sound, light, the concurrent a kind of physical phenomenon of electricity that occurs in the atmosphere, typically refers to the electric discharge phenomena of charged cloud layer to the earth.If electronic product is struck by lightning, can produce instantaneous overvoltage or overcurrent in its inner circuit, light then influence the performance of electronic product, heavy then can produce not destroying of irrecoverable property to electronic product.
Use as industrial electronics, reliability of products causes closes importantly, and such as the LED driving power of open air, it causes driving power or light fixture to be struck by lightning easily and damage when thunderstorm weather, after lamp extinguishes, and the immeasurable loss that it will cause.At first, most outdoor lamp products are that install in the high-altitude, and it is high that thunderbolt damages the back replacement cost; Secondly, when outdoor lamp suffers thunderbolt to cause fraction defective higher, the image of influence municipal administration easily; In addition, " blackout " situation after lamp puts out, occurs and cause serious accident easily.Therefore, when carrying out the design of electronic product, must adopt the lightning Protection Design technology,, and prevent that thunder and lightning from producing the damage of irrecoverable property to electronic product with the performance impact of reduction thunder and lightning to electronic product.
In the shocking preventing technology that present many places such as highway, airport, subway, harbour, parking lot, school, hospital, ward, factory etc. take; Generally be L-N-FG (line-line-ground) 2KV or L-N (line-line) 2KV; L-FG; N-FG (line-ground) 4KV, the lightning protection grade is low, and mostly product is that the damage type is irrecoverable.
So, be necessary to study in fact, provide a kind of lightning protection grade high, the lightning protection circuit simple, practical, that applicability is strong.
Summary of the invention
For addressing the above problem, the purpose of the utility model is to provide the dropout type lightning protection circuit that a kind of lightning protection grade is high, simple, practical, applicability is strong.
For realizing above-mentioned purpose, the technical scheme of the utility model is:
A kind of dropout type lightning protection circuit includes live wire circuit, zero line circuit and ground path; Wherein, be connected with first piezo-resistance, second piezo-resistance, the 3rd piezo-resistance, the 4th piezo-resistance and accident indicator circuit and discharge tube between live wire circuit and the zero line circuit.
Further, said accident indicator circuit includes resistance R 1, LED light-emitting diode and the dropout protection switch that is connected in series between live wire and the zero line.
Further, said dropout protection switch one end connects zero line, and the other end also connects with first, second piezo-resistance that is connected in parallel in except being connected to light-emitting diode.
Further, be connected in series with dropout protection switch formation again after said first piezo-resistance, the second piezo-resistance parallel connection, form the dual lightning protection of first order line-line.
Further; Said the 3rd piezo-resistance one end connects live wire; The other end is connected to zero line through discharge tube ground connection with through the 4th piezo-resistance respectively; Thereby form the second level L line-ground lightning protection that constitutes by the 3rd piezo-resistance and discharge tube, and the third level N line-ground lightning protection that constitutes by the 4th piezo-resistance and discharge tube.
Compared to prior art; The effective mating reaction of this creation through the three-level protective circuit makes most of surge of power port in the first order, second level protective circuit, just be absorbed or releases, residual surge through in the third level protective circuit once more by effective inhibition; Surge energy is further weakened; Improved the surge protection efficient of whole protecting circuit effectively, for the electronic equipment of rear end provides safe operational environment, for the reliability of electronic equipment provides guarantee.
Description of drawings
Fig. 1 is the circuit theory diagrams of the utility model.
For purpose, technical scheme and advantage that the present invention is created is clearer,, the present invention's creation is further elaborated below in conjunction with accompanying drawing and embodiment.Should be appreciated that specific embodiment described herein only in order to explanation the present invention, and be not used in qualification the present invention.
Please with reference to shown in Figure 1, the present invention creates the dropout type lightning protection circuit and includes live wire circuit L, zero line circuit N and ground path G; Wherein, be connected with the first piezo-resistance M1, the second piezo-resistance M2, the 3rd piezo-resistance M3, the 4th piezo-resistance M4 and accident indicator circuit and discharge tube AR1 between live wire and the zero line.
Said accident indicator circuit includes resistance R 1, LED LED 1 and the dropout protection switch F1 that is connected in series between live wire and the zero line.Said dropout protection switch F1 one end connects zero line N, and the other end also connects with the first piezo-resistance M1 that is connected in parallel in, the second piezo-resistance M2 except that connecting LED 1.Constitute with dropout protection switch F1 again after the said first piezo-resistance M1, the second piezo-resistance M2 parallel connection and be connected in series the dual lightning protection of formation first order line-line.
Said the 3rd piezo-resistance M3 one end connects live wire; The other end is connected to zero line through discharge tube AR1 ground connection with through the 4th piezo-resistance M4 respectively; Thereby form the second level L line-ground lightning protection that constitutes by the 3rd piezo-resistance M3 and discharge tube AR1, and the third level N line-ground lightning protection that constitutes by the 4th piezo-resistance M4 and discharge tube AR1.Thereby form live wire to zero line, live wire over the ground, zero line over the ground, totally three grades lightning protection circuit has improved the lightning protection degree of protection.
Under normal operation, the piezo-resistance in the three-level protective circuit, discharge tube AR1 all are high-impedance state, and indicating device is luminous, and whole anti-surge circuit can not influence the operate as normal of circuit.When surge voltage that producing because of thunderbolt or switch moment plug appears in power port, DM EMI acts on first order dual-protection circuit earlier and is absorbed or releases.Surge voltage gets into second level protection when common mode disturbances, third level protective circuit absorbs surge or release; Vertiginous electric current suppresses surge voltage level transmission backward after through the three-level protective circuit; When residual surge passed through the afterbody protective circuit, the surge voltage of its final residue was basically all in the scope that general electronic equipment can bear, through actual testing authentication; This anti-surge protection circuit can bear>the above surge impact of 6KV; Through effective mating reaction of three-level protective circuit, the surge voltage that gets into back end electronics is reduced to below the 1.5KV basically, for the reliability of electronic equipment provides certain guarantee.In the present embodiment, the preferential ceramic gas discharge tube of gas discharge tube, because the insulation impedance of gas discharge tube is big, the leakage current of its generation is little.Avoided in the circuit due to leakage current big and produce the electronic component problem on fire of generating heat.
The power input of the utility model dropout type lightning protection circuit serial or parallel connection electronic equipment all has same effect, and dropout protection switch F1 broke off after the dropout type lightning protection circuit loses efficacy, and then can not damage the power supply of electrical network bio-occlusion LED driving power.1 of LED LED in the indicating device extinguishes, and prompting the attendant change.
During use, the utility model lightning protection circuit is connected on the power input of electronic equipment, external power supply is earlier through behind the utility model, supplies power inputing to electronic equipment.This lightning protection circuit is through effective mating reaction of three-level protective circuit; Make most of surge of power port in the first order, second level protective circuit, just be absorbed or release; Residual surge passes through in the third level protective circuit once more by effective inhibition; Surge energy is further weakened, and the surge voltage of the entering back end electronics of its final residue basically all below 1.5KV, has improved the surge protection efficient of whole protecting circuit effectively; For the electronic equipment of rear end provides safe operational environment, for the reliability of electronic equipment provides guarantee.
The above is merely preferred embodiment of the present invention, not in order to restriction the present invention, all any modifications of within spirit of the present invention and principle, being done, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.