CN2462638Y

CN2462638Y - Fluorescent lamp electronic ballst with abnormal state protection

Info

Publication number: CN2462638Y
Application number: CN 01217042
Authority: CN
Inventors: 沈卫军
Original assignee: Wuxi Balas Lighting Electronics Co Ltd
Current assignee: Wuxi Balas Lighting Electronics Co Ltd
Priority date: 2001-01-03
Filing date: 2001-01-03
Publication date: 2001-11-28
Anticipated expiration: 2011-01-03

Abstract

The utility model relates to a fluorescent lamp electronic ballast with abnormal state protection, which comprises a filter circuit 1, a rectifying filter circuit 2, a DC/AC inverter circuit 3, an output network circuit 4 and an automatic abnormal state protection circuit 9, wherein, the protection circuit 9 is connected between the output end of the output network circuit 4 and the DC/AC inverter circuit 3, and comprises a sample circuit 5, a half-wave rectifying filter circuit 6 and an abnormal control circuit 7, wherein, the sample circuit 5 has C1, R1 and R2; the half-wave rectifying filter circuit 6 has D1, C2 and R3; the abnormal control circuit 7 has D2 and V3. The utility model has the characteristics of simple structure, low cost, high reliability, easy production and debugging, etc.

Description

Electronic ballast for fluoresent lamp with abnormal condition protection

The utility model relates to a kind of electric ballast, relates in particular to a kind of electronic ballast for fluoresent lamp with abnormal condition protection.Belong to the photoelectric source technical field.

Electric ballast does not in the market have the abnormal condition protection function mostly, and when fluorescent tube can not conducting be lighted because of certain reason, electric ballast can damage too greatly because of load.The safe in utilization of this kind ballast can not be protected.Do not meet national standard yet.Rare some have the ballast of abnormal condition protection on the market, or lack the market competitiveness because of circuit complexity, cost are too high, or because of the circuit debugging difficulty, easily affected by environment and generation misses to be protected, and causes the lamp cisco unity malfunction.For a long time, people always research and development have reliability height, cost low, debug easily that protective circuit is used for electric ballast.

The purpose of this utility model is to provide a kind of and has simple in structurely, with low cost, and the reliability height, produces the electronic ballast for fluoresent lamp that debugging is easy to protective circuit.

The purpose of this utility model is achieved in that a kind of electronic ballast for fluoresent lamp with abnormal condition protection; comprise filter circuit, current rectifying and wave filtering circuit, DC/AC inverter circuit and output network circuit and abnormality automatic protection circuit, the abnormality automatic protection circuit is connected between the output and DC/AC inverter circuit of output network circuit.

Protective circuit of the present utility model includes sample circuit, halfwave rectifier filter circuit and unusual control circuit.

Sample circuit of the present utility model comprises capacitor C 1 and resistance R 1, R2, the halfwave rectifier filter circuit comprises diode D1, capacitor C 2 and resistance R 3, unusual control circuit comprises diode D2 and triode V3, its circuit connects as follows: sample circuit capacitor C 1 one terminates at the output of output network circuit choke induction L3, the other end successively with resistance R 1, the R2 back that is connected in series links to each other with the direct current negative terminal of the D3～D6 bridge-type ballast of rectifier filter circuit, the positive pole of the diode D1 of half-wave ballast filter circuit is connected on R1, on the contact of R2, the positive pole of negative pole and capacitor C 2, the negative pole of resistance R 3 and unusual control circuit diode D2 links to each other, and the other end of the negative pole of capacitor C 2 and resistance R 3 is connected on the direct current negative terminal of the D3 of current rectifying and wave filtering circuit～D6 bridge rectifier; The positive pole of diode D2 links to each other with the base stage of triode V3, and the collector electrode of V3 links to each other with the base stage of DC/AC inverter circuit triode V2, and the emitter of triode V3 is also linked the direct current negative terminal of current rectifying and wave filtering circuit D3～D6 bridge rectifier.

Owing to adopt such scheme, make electric ballast gap under abnormality work and reduce power output automatically, reached the purpose of protecting.And after abnormality was excluded, ballast can recover operate as normal automatically, need not to reset.Generally after the output loading of ballast was determined, its protective circuit need not any debugging, gets final product reliably working, has simplified production technology greatly, and cost is in 1 yuan.Therefore simple in structure, with low cost, and the reliability height.Have broad application prospects.

Fig. 1 is a theory diagram of the present utility model.

Fig. 2 is a circuit diagram of the present utility model.

Fig. 3 is the circuit theory diagrams of an embodiment of the present utility model.

Make a detailed description below in conjunction with the accompanying drawing utility model of becoming a partner:

See Fig. 1; the utility model is a kind of electronic ballast for fluoresent lamp with abnormal condition protection; comprise electromagnetic interface filter circuit 1; current rectifying and wave filtering circuit 2; DC/AC inverter circuit 3; output network circuit 4 and abnormality automatic protection circuit 9; wherein the electromagnetic interface filter circuit 1; current rectifying and wave filtering circuit 2; DC/AC inverter circuit 3 and output network circuit 4 connect to form basic circuit 8; and protective circuit 9 is by sample circuit 5; halfwave rectifier filter circuit 6 and unusual control circuit 7 connect to form; protective circuit 9 is connected between the tie point and DC/AC inverter circuit 3 of output network circuit 4 and fluorescent tube 10; gather the level magnitude that output network circuit 4 is imported fluorescent tubes 10 by sample circuit 5, through by unusual control circuit 7 decisions DC/AC inverter circuit 3 being quit work behind the halfwave rectifier filter circuit 6 detection ripples.When in circuit, abnormal signal being arranged; the level magnitude of input fluorescent tube tend to surpass when working under the normal condition more than one times; at this moment often much higher by the level magnitude calibration of sample circuit 5 and halfwave rectifier filter circuit 6; unusual control circuit 7 conductings; DC/AC inverter circuit 3 is quit work, play a protective role.

According to above scheme, Fig. 2 has provided physical circuit.Form two π type electromagnetic interface filter circuit 1 by C3, L1, C4.D3～D6 and C5 form current rectifying and wave filtering circuit 2.Diode D7～D10, capacitor C 6～C8, resistance R 4～R11, inductance L 2a～L2c and two transistor V1, V2 form DC/AC inverter circuit 3, and capacitor C 9, C10 and inductance L 3 constitute output network circuit 4.Core technology protective circuit 9 of the present utility model is: by the sample circuit 5 that capacitor C 1, resistance R 1, R2 series connection constitute, be connected between the direct current negative terminal negative pole of D3～D6 bridge rectifier of the tie point of output network circuit 4 choke induction L3 and fluorescent tube 10 and current rectifying and wave filtering circuit 2.Diode D1, capacitor C 2, resistance R 3 constitute halfwave rectifier filter circuit 6.The positive pole of diode D1 is connected on the contact of resistance R 1, R2, negative pole links to each other with the negative pole of the diode D2 of positive pole, resistance R 3 and the unusual control circuit 7 of capacitor C 2, the other end of the negative pole of capacitor C 2 and resistance R 3 is connected on the direct current negative terminal of the D3～D6 bridge rectifier of current rectifying and wave filtering circuit 2, obtain signal by diode D1 from the resistance R 1 of sample circuit 5, the connection mid point of R2, through capacitor C 2 filtering, resistance R 3 is intended C2 is being provided a discharge loop; The unusual control circuit of forming by diode D2, triode V3 7.Wherein the negative pole of Zener diode D2 links to each other with the negative pole of the rectifier diode D1 of half-wave rectifying circuit 6, the positive pole of D2 links to each other with the base stage of switch control triode V3, and the collector electrode of V3 is connected on the base stage of triode V2 of DC/AC inverter circuit 3, the emitter of V3 links to each other with the end of the emitter resistance R6 of V2, is connected on the direct current negative terminal of bridge rectifier of the D3～D6 of current rectifying and wave filtering circuit 2 then; The negative pole of filter capacitor C5; Triode V3 is as if saturation conduction, and then the V2 base potential is lowered to below the threshold voltage, and V2 ends, 3 failures of oscillations of DC/AC inverter circuit, thereby play a protective role.The detailed operation principle is described below:

Under the normal condition, the DC/AC inverter circuit 3 that triode V1, V2 and resistance, electric capacity, inductance element are formed is lighted fluorescent tube by output choke induction L3, the signal of telecommunication that sampling capacitance C1 gathers enters diode D1 rectification and through C2 filtering through R1, R2 voltage divider, at this moment level value is lower, deficiency is so that Zener diode D2 conducting, so triode V3 can not get signal and is in cut-off state.Protective circuit is not worked.When fluorescent tube the complete and lamp of filament occurs and abnormality such as can not normally light line power tend to surpass work under the normal condition more than one times; the higher meeting of signal amplitude frequently of sampling electricity makes Zener diode D2 puncture conducting; triode V3 is saturation conduction immediately; triode V2 base potential is lowered to below the threshold voltage; so V2 ends; 3 failures of oscillations of DC/AC inverter circuit play a protective role.But after the DC/AC inverter circuit quit work, the level of sample circuit collection also was zero, and Zener diode D2 turn-offs, and triode V3 also ends, and the DC/AC inverter circuit is resumed work again.But as long as abnormality is not got rid of, protective circuit will be moved again again, and the DC/AC circuit is quit work; also promptly under abnormality; the output of electron rectifier is discontinuity, thereby has reduced power output, has protected electric ballast and unlikelyly damages under abnormality.Above scheme has provided the pattern of the protective circuit of the push-pull oscillator DC/AC inverter circuit that double pole triode forms.For a people who has electronics knowledge slightly,, also can be used in the DC/AC inverter circuit of device rate of doing work converters such as adopting power switch MOSFET, igbt to circuit conversion a little.

Make in order to realize abnormality occurring the DC/AC inverter not produce gap work phenomenon and disposable shutoff.Can between unusual control circuit 7 Zener diode D2 and switch control triode V3, insert " triggering level holding circuit " 11 (as Fig. 3), this holding circuit also can be made up of the circuit of other similar effect, thereby makes V3 promptly be locked in conducting state once conducting.These holding circuits can make the V3 base stage obtain a lasting electricity saturation conduction frequently and always of keeping, the DC/AC inverter is quit work always, when getting rid of abnormality, as long as cut off primary power source, ballast can be resumed work, " triggering level holding circuit " like this is a lot, and ready-made module can directly be used in the reality.All can use as CD4013 etc.Be easy to realize for the people of these basic circuit knowledge of tool slightly.

Claims

1, a kind of electronic ballast for fluoresent lamp with abnormal condition protection; comprise filter circuit (1), current rectifying and wave filtering circuit (2), DC/AC inverter circuit (3) and output network circuit (4); it is characterized in that it also comprises abnormality automatic protection circuit (9), abnormality automatic protection circuit (9) is connected between the tie point and DC/AC inverter circuit (3) of output network circuit (4) and fluorescent tube (10).

2, a kind of electronic ballast for fluoresent lamp with abnormal condition protection according to claim 1 is characterized in that abnormality automatic protection circuit (9) includes sample circuit (5), halfwave rectifier filter circuit (6) and unusual control circuit (7).

3; a kind of electronic ballast for fluoresent lamp according to claim 2 with abnormal condition protection; it is characterized in that sample circuit (5) comprises capacitor C 1 and resistance R 1; R2; halfwave rectifier filter circuit (6) comprises diode D1; capacitor C 2 and resistance R 3; unusual control circuit (7) comprises diode D2 and triode V3; its circuit connects as follows: sample circuit (5) capacitor C 1 one terminates at the tie point of output network circuit (4) choke induction L3 and fluorescent tube (10); the other end successively with resistance R 1; the R2 back that is connected in series links to each other with the direct current negative terminal of the D3～D6 bridge-type ballast of rectifier filter circuit (2); the positive pole of the diode D1 of half-wave ballast filter circuit (6) is connected on R1; on the contact of R2; the positive pole of negative pole and capacitor C 2; the negative pole of resistance R 3 and unusual control circuit (7) diode D2 links to each other; the other end of the negative pole of capacitor C 2 and resistance R 3 is connected on the direct current negative terminal of the D3～D6 bridge rectifier of current rectifying and wave filtering circuit (2); the positive pole of diode D2 links to each other with the base stage of triode V3; the collector electrode of V3 links to each other with the base stage of DC/AC inverter circuit triode V2, and the emitter of triode V3 is also linked the direct current negative terminal of current rectifying and wave filtering circuit 2D3～D6 bridge rectifier.

4,, it is characterized in that between unusual control circuit (7) Zener diode D2 and triode V3, inserting triggering level holding circuit (10) according to claim 2 or 3 described a kind of electronic ballast for fluoresent lamps with abnormal condition protection.