CN2565231Y

CN2565231Y - Efficient electronic ballast

Info

Publication number: CN2565231Y
Application number: CN 02217958
Authority: CN
Inventors: 曾浩然
Original assignee: FEIHONG ELECTRONIC (SHANGHAI) Co Ltd
Current assignee: FEIHONG ELECTRONIC (SHANGHAI) Co Ltd
Priority date: 2002-06-05
Filing date: 2002-06-05
Publication date: 2003-08-06
Anticipated expiration: 2012-06-05

Abstract

The utility model relates to an efficient electronic ballast, which comprises a rectification filtering power factor correcting circuit, an abnormality protection circuit, a triggering start circuit, a half-bridge oscillating circuit, and an output circuit, wherein, a half-bridge self-excited oscillating front-end circuit is coupled in between the triggering start circuit and the half-bridge oscillating circuit. The utility model enlarges the electric current of a lamp tube, enhances the tube temperature when the lamp tube works, increases the output capability of the electronic ballast, improve s the switching characteristics of the power devices, overcomes the uprush hidden danger caused by the inherent DC voltage of a simple pump power factor correction circuit at the time of switching on a power supply, realizes the reliability of the protection circuit under the condition of overdriving or the change of the voltage of the power supply, avoids the misoperation of the protection circuit under the normal working state, and thus, enhances the reliability of the complete machine. The utility model can cause a fluorescent tube to send out light of which the lightness is equal to the lightness of the light of two lamp tubes only by increasing few devices during manufacturing.

Description

High-effect electric ballast

Technical field

The utility model relates to the electrical lighting technical field, particularly a kind ofly inserts the high-effect electric ballast that band is forbidden the semi-bridge autonomous vibration front end circuit held.

Background technology

Fluorescent lamp is a kind of energy-conservation, efficient, green illumination light source that colour temperature can be controlled, and its being extensive use of in every field impels people that it is carried out deep research, excavates its potential to greatest extent, makes it more energy-conservation, efficient.Thereby when improving the fluorescent tube performance, also matching used electric ballast is with it carried out more deep exploration.

At present, in the prior art for improving the light efficiency of fluorescent lamp, have two kinds of approach available: the one, the fluorescent tube of the high light efficiency of selection, also promptly select the higher fluorescent tube of lumen per watt number (lm/w), as the popular T5 that the promotes gradually in the world (fluorescent tube of Φ=17mm) in Europe in recent years, the highest light efficiency can reach 104 lumens/watt, and common straight type fluorescent tube is only between 55～65 lumens/watt; The 2nd, the usefulness of raising electric ballast itself reduces oneself power consumption.For these two kinds of measures, the former, the T5 fluorescent tube since on the more expensive and size of price with the not versatility of T8 fluorescent tube, and the light fixture renewal cost crosses high reason, also is difficult at home at present promote the use of.The latter is not if adopt an effective measure, and it is also very little to produce effects.

The driving of electric ballast of the prior art works in standard T8 fluorescent tube pipe temperature mostly, the low state of Asia and Africa optimum, thereby its efficiency coefficient value (Lm/W) is lower.In order to realize (over drive) technology of overdriving of fluorescent tube, at first must strengthen the output of electric ballast, also promptly strengthen the electric current of electric ballast output transistor, thereby also brought the saturated heating problem of transistor driving.In addition, under overdrive condition, because the variation of input voltage, be used to vibrate and the base stage of the transistor of power output can cause that switching characteristic can significantly degenerate because of driving deficiency or driving supersaturation, at this moment, the temperature rise of transistor also can significantly raise.

Summary of the invention

Technical problem to be solved in the utility model is to overcome existing defective in the above-mentioned prior art, at the T8 fluorescent tube that comparatively generally uses, add on the basis of production cost not increasing basically or reduce, give full play to its potential ability, a kind of high-effect electric ballast is provided.Make its can in the extraordinary utilization of fluorescent tube the performance maximum efficiency.Concrete technical problem to be solved is:

1, increase electric ballast to the lamp tube current driving force, improve the light output intensity of fluorescent tube;

2, when increasing the electric ballast fan-out capability, improve the switching characteristic of its power device, reduce the power consumption of self;

3, improve the abnormal protection circuit, strengthen the fail safe and the reliability of complete machine.

The utility model has adopted following technical proposal to solve its technical problem: a kind of high-effect electric ballast comprises the rectifying and wave-filtering circuit of power factor correction, abnormity protection circuit, trigger starting circuit, half-bridge oscillation circuit and the output circuit that connect successively.It is characterized in that: between trigger starting circuit and half-bridge oscillation circuit, insert a band and forbid the semi-bridge autonomous vibration front end circuit held.

The utility model strengthens lamp current by ballast, and the Guan Wen when improving lamp works can make the luminous efficiency of T8 three primary colors bring up to 105Lm/W from 92Lm/W, has met or exceeded the level of novel T5 fluorescent tube basically.When increasing the electric ballast fan-out capability; improve the switching characteristic of its power device; overcome since single pump power factor correcting circuit intrinsic direct voltage in the power connection upper punch hidden danger of moment; and improved overdrive or the situation of mains voltage variations under the reliability of protective circuit; avoid the complete machine misoperation of protective circuit in normal operation, thereby improved the reliability of complete machine.

The utility model only increases less components and parts during fabrication, also only increases by the power of 8 ~ 9W in actual use, just can make a fluorescent tube send the brightness that is equivalent to two fluorescent tubes, has higher economic value.

Description of drawings

Fig. 1 the utility model circuit structure block diagram;

Fig. 2 the utility model circuit theory diagrams;

Fig. 3 the utility model principle analysis figure.

Embodiment

Come the utility model is further described below in conjunction with accompanying drawing and embodiment.

With reference to Fig. 1, the utility model comprises rectifying and wave-filtering circuit of power factor correction 1, abnormity protection circuit 2, trigger starting circuit 3, half-bridge oscillation circuit 5 and the output circuit 6 that connects successively.Between trigger starting circuit 3 and half-bridge oscillation circuit 5, insert a band and forbid the semi-bridge autonomous vibration front end circuit 4 held.

With reference to Fig. 2, in the semi-bridge autonomous vibration front end circuit 4 that band described in the utility model is forbidden holding, one termination high pressure anode B of capacitor C 3, the other end then connects base stage and the resistance R 5 of transistor Q1, the emitter of another termination transistor Q1 of this resistance R 5, and be connected with diode D1 negative terminal in the trigger starting circuit 3, the collector electrode of transistor Q1 then is connected to the transistor Q3 base stage in the half-bridge oscillation circuit 5; One end of capacitor C 4 is connected with diode D1 negative terminal in the trigger starting circuit 3, the other end of this capacitor C 4 connects the base stage of transistor Q2, and be connected with the anode of voltage stabilizing didoe D2 and an end of resistance R 6, the emitter of the other end of resistance R 6 and transistor Q2 links to each other and ground connection A, and the collector electrode of transistor Q2 then is connected to the base stage of the transistor Q4 in the half-bridge oscillation circuit 5.

In abnormity protection circuit 2 described in the utility model; the anode of unidirectional controllable silicon S CR connects the mid point of resistance R 1, R2: and negative electrode links to each other with the negative terminal of resistance R 4 with voltage stabilizing didoe D2; the other end ground connection of resistance R 4; the base stage b of the positive termination transistor Q2 of voltage stabilizing didoe D2, and be connected with an end of capacitor C 4, resistance R 6.

With reference to shown in Figure 2, after energized, behind electromagnetic compatibility filter circuit, rectification circuit, power factor alignment circuit and the filter circuit of AC power in circuit 1, export a dc high voltage, put between A, the B end in the circuit.This direct voltage charges to capacitor C 2 by resistance R 1, R2, along with two terminal voltages of capacitor C 2 raise gradually, in case after the voltage of bidirectional diode DIAC1 two ends surpasses its puncture voltage, the voltage of capacitor C 2 two ends is just by bidirectional diode DIAC1, resistance R 7, R9, the interior conductive discharge of the winding N13 of transformer T1 and the base stage b of transistor Q4 and emitter e.This positive voltage makes transistor Q4 be tending towards conducting, and mid point output is faced in ground connection.

See another charge circuit again, this moment, positive high voltage just made transistor Q4 charging by the winding N21 of capacitor C 7, C9, transformer T2 and the N11 winding of T1.Under the effect of this charging current,, and make the further conducting of transistor Q4 and gradually in saturated, this moment, transistor Q3 then more was tending towards ending because the just feedback of transformer T1 connects.The higher-order of oscillation is by resistance R 1, R2, R7, and capacitor C 2 and bidirectional diode DIAC1 form start-up circuit 3 and start, the foundation of vibration and to keep then be that coupling by means of between saturable transformer T1 winding realizes.When making transformer T1, charging current is saturation condition, then making N12 and the N13 induced voltage of T1 is zero, reducing and approach zero along with charging current, because the induced voltage of transformer T1 is reverse and positive feedback effect, transistor Q3 conducting, transistor Q4 are ended, form an oscillatory process repeatedly therefrom.

The utility model has adopted (Over drive) technical scheme of overdriving to the T8 fluorescent tube, strengthens the electric current of fluorescent tube, improves the Guan Wen of lamp, makes it that Guan Wen reaches 55 ℃ when work, and its light efficiency reaches 104lm/w, maintains an equal level in the BEF value of T 5 fluorescent tubes.Experimental results show that, overdriving to influence the life-span of fluorescent tube, and for example we have reached its technical performance index 70,000 times to the ON-Off test of a certain model fluorescent tube, be better than greatly aspect light efficiency outside the fluorescent tube of normal parameter utilization, other parameter also And is inferior unlike it.

The utility model is except that adopting fluorescent tube the overdrive scheme, and the transistor of the output that is used to vibrate has also been implemented overdrive scheme, and to and the problem that produces forbids that by the band that is provided with the semi-bridge autonomous vibration front end circuit of holding 4 is properly settled.

With reference to shown in Figure 2, constitute the compensating circuit of transistor Q3 and constitute the compensating circuit of transistor Q4 by capacitor C 4, resistance R 6, transistor Q2 by capacitor C 3, resistance R 5, transistor Q1.In the moment of energized, the high pressure anode of rectification output is to resistance R 1, R2, in the time of capacitor C 2 chargings, the also capacitor C 3 in the semi-bridge autonomous vibration front end circuit 4 that band is forbidden holding, resistance R 5 and capacitor C 4, resistance R 6 chargings, because capacitor C 3, electric capacity is measured smaller value during capacitor C 4 designs, hundreds of approximately pF, thereby the RC time constant is less, so the charging interval is very short, and in resistance R 5, the moment that obtains on the R6, positive voltage made transistor Q1, the Q2 conducting, transistor Q3, Q4 is in the moment cut-off state, and be able to Vent rapidly and put, so not only can not influence the startup of electric ballast, and improved circuit in the reliability of moment of energized, that is:

1, show the moment of connecting switch, transistor Q3, Q4 end, and have reduced starting current, have improved whole aircraft reliability.

2, show the moment of connecting switch, because transistor Q3, Q4 end, so the signal voltage that feeds back on single pump power factor correcting circuit by capacitor C 10 is zero, give transistor Q3, Q4, the problem of withstand voltage of bringing and overcome VBA direct voltage upper punch when start effectively.

After the circuit operate as normal, for example if transistor Q4 is in conducting state, it is positive voltage that the induced voltage that is produced by the N13 winding of transformer T1 puts on transistor Q4 base stage (also being the collector electrode of transistor Q2) by resistance R 9, and when the N13 of transformer T1 winding induced voltage by just going to zero and oppositely the time, transistor Q4 is tending towards ending by conducting.Otherwise transistor Q3 is then, by by being tending towards conducting, and in this transfer process,

Positive direct voltage is then given capacitor C 4, resistance R 6 chargings by transistor Q3, the positive voltage of resistance R 6 two ends puts between the base-emitter of transistor Q2, make it the moment conducting, thereby the electric charge that accumulates in transistor Q4 base stage is immediately discharged, quicken transistor Q4 from being conducting to the process of ending, reduce the switching loss of transistor thus greatly, thereby make the heating that causes owing to overdriving of transistor be able to perfect the solution.

The utility model circuit has also solved because input supply voltage when changing, (for example from 220V ~ change to 242V ~), the drift of the working point of circuit.This is because of the rising along with direct voltage, and compensation also strengthens event.After having used this circuit, the switching loss of transistor is very little, and does not change because of the variation of input voltage.And general its switching loss of circuit is bigger, and the square-wave voltage of output has very high spike to occur when rising and descend, and this is with the transistorized safety of entail dangers to.

With reference to shown in Figure 3, the negative terminal of the resistance R 4 one termination voltage stabilizing didoe D2 in one-way SCR (SCR) cathode return circuit, other end ground connection, the base stage of the positive termination transistor of voltage stabilizing didoe D2 Q2 also is connected with an end of resistance R 6, capacitor C 4.In the abnormity protection circuit of prior art, do not establish voltage stabilizing didoe D2.In fact; when the collector electrode of transistor Q2 is in reverse voltage (negative voltage); the PN junction of the bc of transistor Q2 is in forward conduction; there is a current Ib c to flow through resistance R 4 (with reference among Fig. 3 shown in the arrow); voltage drop that is produced and abnormity protection circuit are in resistance R 3; voltage drop forward stack on the capacitor C 1 puts between the control utmost point-negative electrode of unidirectional controllable silicon S CR; when circuit is adjusted improper or raise and when drawing the variation of parameter by ambient temperature; unidirectional controllable silicon S CR very easily causes misoperation, just can avoid such problem when increase this voltage stabilizing didoe D2 in circuit.

Claims

1, a kind of high-effect electric ballast; comprise successively the rectifying and wave-filtering circuit of power factor correction (1), abnormity protection circuit (2), trigger starting circuit (3), half-bridge oscillation circuit (5) and the output circuit (6) that connect, it is characterized in that: between trigger starting circuit (3) and half-bridge oscillation circuit (5), insert one and be with and forbid the semi-bridge autonomous vibration front end circuit (4) held.

2, high-effect electric ballast according to claim 1, it is characterized in that: a termination high pressure anode (B) of electric capacity (C3) in the semi-bridge autonomous vibration front end circuit (4) that described band is forbidden holding, the other end then connects the base stage and the resistance (R5) of transistor (Q1), the emitter of another termination transistor (Q1) of this resistance (R5), and be connected with diode (D1) negative terminal in the trigger starting circuit (3), the collector electrode of transistor (Q1) then is connected to transistor (Q3) base stage in the half-bridge oscillation circuit (5); One end of electric capacity (C4) is connected with diode (D1) negative terminal in the trigger starting circuit (3); the other end of this electric capacity (C4) connects the base stage of transistor (Q2); and with abnormity protection circuit (2) in the anode of voltage stabilizing didoe (D2) and an end of resistance (R6) be connected; the emitter of the other end of resistance (R6) and transistor (Q2) links to each other and ground connection (A), and the collector electrode of transistor (Q2) then is connected to the base stage of the transistor (Q4) in the half-bridge oscillation circuit (5).