CN2071415U - Energy-saving electronic ballast for fluorescent lamp - Google Patents

Abstract

The energy-saving electronic ballast of the fluorescent lamp consists of an input circuit (1), a rectifying and filtering circuit (2), a push-pull power oscillation and driving circuit (3), a common-state conduction preventing circuit (4), a sine wave conversion and ballast circuit (5) and a filament parallel circuit (6), wherein the input circuit (1) comprises an inductor L with a common magnetic core₁And L₂And a capacitor C₁、C₂And C₃. The common-state conduction preventing circuit (4) is composed of a diode D₅Resistance R₄And a capacitor C₇And (4) forming. Therefore the utility model discloses except that possess that current electronic ballast has energy-conservation showing, power factor is high, do not have to exchange humming sound and stroboscopic and weight and alleviate advantages such as greatly, still less than general electronic ballast's external noise interference, circuit operational reliability is high, and high-power triode is not fragile.

Description

Electronic power saving ballast for fluorescent lamp

The utility model relates to a kind of circuit arrangement of controlling fluorescent lamp.

Is developing and small lot batch manufacture in the existing producer of China the electronic ballast for fluorescent lamps, patent has also been applied in product that has or design, they are compared with existing inductance type ballast, have obviously energy-conservation, power factor is high, no AC hum and stroboscopic, can disposable starter and the advantage that alleviates greatly of weight.But mostly there are the following problems for these electric ballasts: (1) radio interference and noise to external world is bigger; (2) functional reliability is relatively poor, its main cause is that the pusb pull oscilator high power valve in the circuit is easy to generate the common-mode conducting and causes transistor to burn, the fluctuating range of external voltage is big in addition, the peaking voltages that surge current and external interference and vibration square wave front edge and back are produced along distortion etc. are to the impact of oscillating tube, possibility that causes transistor to damage all arranged, and existing electric ballast does not take to prevent that common-mode conducting measure or measure are insufficient.

Therefore, the purpose of this utility model is to provide a kind of radio noise to external world to disturb electronic ballast for fluoresent lamp less, reliable working performance.

Design of the present utility model is on the basis of the basic circuit of existing electric ballast, its input circuit and anti-common-mode turning circuit part is improved realized.

Below in conjunction with drawings and Examples the utility model is described in detail.

Fig. 1 is the utility model circuit frame principle figure;

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

Referring to Fig. 1, the utility model by common input circuit (1), rectification and filter circuit (2), recommend power oscillation and drive circuit (3), anti-common-mode turning circuit (4), sinusoidal wave conversion and ballasting circuit (5) and filament shunt circuit (6) form external fluorescent tube (7) when this electric ballast is worked.Its operation principle is, single phase alternating current power supply carries out rectifying and wave-filtering through circuit (1) to circuit (2), circuit (2) supply circuit (3) is with DC power supply, circuit (4) is prevented the control of common-mode conducting to circuit (3), the square wave oscillation signal of circuit (3) output is transformed into the supersonic frequency sine wave signal through circuit (5) and supplies with fluorescent tube (7), circuit (6) is connected in parallel on the two ends of fluorescent tube (7) filament, circuit (5) forms series resonance by filament and circuit (6), provides preheat curent and starter high pressure to fluorescent tube (7).Circuit (1) plays a part to suppress Circuits System radio noise to external world and disturbs between external power and this device circuit system.

Referring to Fig. 2, input circuit (1) comprises fuse RD, is total to the inductance L of magnetic core ₁With L ₂And capacitor C ₁, C ₂With C ₃, L wherein ₁With L ₂Seal in the input circuit (1) C respectively ₁Be connected in parallel on the output of input circuit (1), C ₂With C ₃Two its two ends, back that are in series are connected in parallel on the output of input circuit (1) and C ₂With C ₃Tie point with ground join.This input circuit form.Both can remove the high frequency parasitics electric current that circuit of electronic ballast system itself is caused, and disturb to suppress its radio noise to external world, and can remove the interference of external voltage to Circuits System itself again, rectification and filter circuit (2) are by diode D ₁To D ₄, capacitor C ₄With C ₅And resistance R ₁Become.Recommending power oscillation and drive circuit (3) comprises by resistance R ₃, capacitor C ₆And bidirectional diode D ₇The saw-toothed wave generator of forming and by large power triode T ₁With T ₂, diode D ₆, oscillation transformer B ₁And resistance R ₅To R ₈That forms recommends power oscillation and driver.Saw-toothed wave generator is to recommending power oscillation and driver provides triggering signal, Qi Zhenhou, C ₆Through D ₆, T ₂And R ₈Discharge, triggering finishes.Recommend power oscillator and the 300V DC power supply is changed into the square wave power of 20-30KHZ.R ₆And R ₈Give T respectively ₁And T ₂Provide negative feedback voltage, to improve the stability of square-wave signal.Anti-common-mode turning circuit (4) is by diode D ₅, resistance R ₄And capacitor C ₇Form, wherein D ₅Be connected in parallel on triode T ₁Collection, emitter-base bandgap grading between, R ₄With C ₇Be connected in parallel on triode T respectively ₁Collector electrode and T ₁The connecting resistance R of emitter institute ₆Between the lower end.D ₅, C ₇And R ₄Effect, be to make large power triode T ₁With T ₂Can be in stable saturation conduction or cut-off state, square wave front edge and back be along precipitous, two pipes by and the friendship of conducting to get over the time elongated, and can prevent peak voltage, thereby can avoid the common-mode conducting occurring and damage power tube.Sinusoidal wave conversion and ballasting circuit (5) are by inductance L ₃And capacitor C ₁₀Form, it provides the supersonic frequency sine voltage of 20-30KHZ, the inductance L of the band magnetic core that volume is very little to fluorescent tube (7) ₃When the fluorescent tube normal ignition, has current-limiting function again.Filament shunt circuit (6) is by resistance R ₉With capacitor C ₁₁Form L ₃And C ₁₀By filament and C ₁₁And R ₉The formation series resonant circuit that is together in series successively provides starting voltage about preheat curent and 400V to fluorescent tube (7).

The utility model electric ballast has been owing to taked strong interference protection measure at input circuit, so to external world radio noise disturbs gentlyer during work, after tested, reached state specified standards.Because the measure that anti-common-mode turning circuit is taked is abundant, input circuit also has simultaneously and suppresses the effect of external voltage to Circuits System interference itself well in addition, so power tube can not damage easily, the reliability and stability of circuit working improve greatly.This electric ballast can with the supporting use of the fluorescent tube of various power.The applicant adopts this kind electric ballast to cooperate with fluorescent tube and the structure of a kind of efficient energy-saving fluorescent lamp of producing is: electric ballast is contained in the printed board, printed board places in the plastic capsule, plastic capsule is being supported lampshade and lamp socket, and fluorescent tube places the lampshade inboard.

Claims (1)

1, a kind of energy-saving electronic ballast of controlling fluorescent lamp, by input circuit (1), rectification and filter circuit (2), recommend power oscillation and drive circuit (3), anti-common-mode turning circuit (4), sinusoidal wave conversion and ballasting circuit (5) and filament shunt circuit (6) are formed, circuit (3) includes large power triode T ₁With T ₂, of the present utility model being characterised in that:

A) input circuit (1) comprises the inductance L of common magnetic core ₁With L ₂And capacitor C ₁, C ₂With C ₃, L wherein ₁With L ₂Seal in the input circuit (1) C respectively ₁Be connected in parallel on the output of input circuit (1), C ₂With C ₃Two its two ends, back that are in series are connected in parallel on the output of input circuit (1) and C ₂With C ₃Tie point with ground join;

B) anti-common-mode turning circuit (4) is by diode D ₅, resistance R ₄And capacitor C ₇Form, wherein D ₅Be connected in parallel on triode T ₁Emitter-base bandgap grading between, R ₄With C ₇Be connected in parallel on triode T respectively ₁Collector electrode and T ₁The connecting resistance R of emitter institute ₆Between the lower end.

Images