CN2163505Y

CN2163505Y - Power source converter for fluorescent lamp

Info

Publication number: CN2163505Y
Application number: CN 93231387
Authority: CN
Inventors: 吴健
Original assignee: WORKER'S SCHOOL OF JINAN RAILWAY SUB-BUREAU
Current assignee: WORKER'S SCHOOL OF JINAN RAILWAY SUB-BUREAU
Priority date: 1993-07-17
Filing date: 1993-07-17
Publication date: 1994-04-27
Anticipated expiration: 2003-07-17

Abstract

The utility model relates to a converter of a straight direct current-alternating current power supply, which adopts the technical proposals that a multivibrator and a trigger are formed into a signal source with excitation pulses, two VMOS high-power transistors and a transformer B are formed into a power output stage, and the secondary stage of a transformer is connected with an LC series resonance loop; the prblems that a traditional converter works with inefficient performance, large power tubes are difficult to match, and fluorescent lamp tubes with filament breakage can not be used are solved. The utility model has the advantages of electric power saving, reliable work, stable work, etc. Besides, fluorescent lamp tubes with broken filaments can be used without the matching of power tubes; production cost can be effectively reduced.

Description

Power source converter for fluorescent lamp

The utility model is a kind of fluorescent lamp power supply converting means.

No matter existing fluorescent lamp converting means is independent-excited or auto-excitation type, or realizes with the push pull mode of two power transistors, or with the power transistor alternate conduction of two parallel connections with by realizing.All there is following feature in they:

(1) ON time of power transistor is the time of half cycle of oscillation;

(2) existing the conducting simultaneously of two power transistors is the phenomenon of common-mode conducting;

(3) require the parameter of two power tubes to mate symmetrically;

(4) filament of fluorescent tube is in case damage just can not continue illumination.

These factors are unfavorable for the operating efficiency of fluorescent lamp transducer, the raising of reliability and fluorescent tube utilance.

The purpose of this utility model just is to eliminate above-mentioned unfavorable factor, improves the utilance of operating efficiency, reliability and the fluorescent tube of fluorescent lamp transducer.

The utility model utilizes monostable flipflop that the symmetrical square wave pulse of oscillation source is become the burst pulse of width less than half cycle of oscillation, combine with the construction features of VMOS high power transistor, come the exciting power pipe with the method that on its grid, forms a sawtooth waveforms of above-mentioned burst pulse top superposition, improved the flux change rate of transformer, both can make the fluorescent lamp normal illumination, shortened the ON time of power tube again, common-mode conducting and temporary impact electric current have been eliminated, the neither essential power tube that mates symmetrically with parameter can obtain the same effect with the symmetrical power tube that mates of parameter again.The additional capacitor in parallel with tube filament in the circuit of the present utility model can make fluorescent tube damage the back at filament and continue illumination.

Following with reference to accompanying drawing 1, the technical scheme of specification utility model.

V _DDC power supply for adding fluctuates between 44-65V; BX is a protective tube; D ₁It is additional diode.

L ₁And C ₁Form the anti-noise filter unit; R ₁, D ₂, C ₂Form the low-voltage power supply unit; V ₁And V ₂It is the VMOS high power valve; N ₁And N ₂Be two elementary windings of transformer, N ₃Be secondary winding, they are unsaturation type winding; L ₂, C ₇And L ₃, C ₉Be the resonant inductance and the electric capacity of two series arms; C ₆, C ₈, C ₁₀, C ₁₁Be that this circuit is connected in parallel on the additional capacitor on the tube filament, after filament damages, can make fluorescent tube continue illumination; C ₁₂Be to establish for absorbing anti-peak voltage; Frame of broken lines and the inner and negative sanction of Roman number symbolic representation fluorescent tube; R ₅And R ₆Can prevent self-oscillation.

IC ₁-IC ₅Belong to same integrated circuit.R wherein ₂, C ₃, IC ₁Form multivibrator, frequency of oscillation can be by R ₂, C ₃Parameter decision; IC ₂Rise and isolate and inverting function; C ₄, R _W1, R ₃And IC ₄Constitute the monostable flipflop that trailing edge triggers, IC ₃And C ₅, R _W2, R ₄, IC ₅Constitute the monostable trigger element that rising edge triggers, their temporary stable state duration can correctly be selected its corresponding Resistor-Capacitor Unit and be regulated R by corresponding Resistor-Capacitor Unit decision separately _W1, R _W2, can determine the duration and the work schedule of their temporary stable state, obtain temporary stable state output, influence and IC that the asymmetry of compensation oscillation source square wave causes less than the half period ₃Late effect, simultaneously can also make unmatched V ₁, V ₂Identical actual effect when obtaining with coupling, thus the launching efficiency of the best obtained.

When inserting U _DAfter, integrated circuit is by R ₁, D ₂, C ₂The unit power supply that constitutes, multivibrator is exported square-wave pulse continuously, and (this example is set in 30KH ₂To 40KH ₂Between a certain frequency on) through IC ₂Isolate and be divided into two-way after anti-phase, the input of one tunnel monostable flipflop that triggers as trailing edge, the input of the monostable trigger element that trigger as rising edge on another road.

Work as IC ₂Output in trailing edge with low level the time, the monostable trigger element that rising edge triggers does not overturn IC ₅Output low level, V ₂End; And the monostable flipflop that trailing edge triggers upset, between temporary steady state period, IC ₄Export a high level burst pulse, its width is less than half cycle of oscillation, through R ₅Be added in V ₁Grid on because the intrinsic turn on voltage threshold of VMOS high power valve and higher input capacitance, at IC ₄Output burst pulse top superposition a sawtooth waveforms, so V ₁Conducting, and end with the disappearance of above-mentioned driving pulse.Because this driving pulse is narrow and do not have a flat-top, so make transformer obtain higher flux change rate, for other energisation mode, shortened the ON time of power tube, the conducting of no common-mode has improved operating efficiency greatly, avoid transformer because of often being in supersaturation and generating heat and power tube bearing bigger impulse current because of magnetic saturation and common-mode conducting, improved the reliability of work.Work as IC ₂When being in rising edge and high level, the monostable flipflop that trailing edge triggers continues to end, and the monostable trigger element that rising edge triggers upset, IC ₅Export a high level burst pulse between steady state period temporarily, its width is also less than half cycle of oscillation, through R ₆Be added in V ₂Grid on, same V ₁Situation similar, V ₂Grid also be subjected to a burst pulse top superposition voltage of a sawtooth waveforms encourage, produce and V ₁Similar effect.As mentioned above, V ₁And V ₂In turn conducting and ending produces the alternating voltage of corresponding frequencies, the branch road at two fluorescent tube places of supply on extremely in transformer B time.

To L ₂, C ₆, C ₇, C ₈With the branch road that fluorescent tube I forms, the generation of resonance depends primarily on L ₂And C ₇Parameter, its series resonance frequency is identical with the frequency of transformer-secondary voltage.Therefore, under the effect of transformer-secondary voltage, L ₂And C ₇Produce series resonance, C ₇On voltage far above transformer-secondary voltage, thereby can start fluorescent tube I luminous lighting.Because C ₆And C ₈Capacitive reactance much larger than the resistance value of tube filament, thereby most electric current flows through filament, do not influence the preheating of filament, after filament damages, L ₂, C ₆, C ₇, C ₈Still constitute path, guaranteed starting as usual and illumination of fluorescent tube.The situation of another branch road and above-mentioned similar, only the generation of its resonance depends primarily on L ₃And C ₉, fluorescent tube and L ₃Be in parallel.

In sum: a kind of high efficiency fluorescent lamp supply convertor comprises band anti-noise filter and unilateral diode (D ₁) and pressurizer (R ₁, D ₂) dc power supply that constitutes, it is characterized in that by integrated circuit (IC ₁), resistance (R ₂), capacitor (C ₃) multivibrator that constitutes, its output inserts by integrated circuit (IC ₂) inverter that constitutes, inverter output respectively with by integrated circuit (IC ₃, IC ₅) constitute the rising edge monostable flipflop, by integrated circuit (IC ₄) control end of the trailing edge monostable flipflop that constitutes links and forms the Pulse-trigger control switching circuit, Pulse-trigger control switching circuit output respectively with VMOS power tube (V too ₁, V ₂), the control grid of the AC power output amplifier formed of transformer (B) links the secondary (N of transformer (B) ₃) on, in parallel at least one group by an inductor and three LC series resonant tank that capacitor constitutes.

Major advantage of the present utility model is the efficient height of supply convertor, reliable operation, noiseless flicker free frequency stabilization, the fluorescent tube that can use filament to damage.In addition, for the requirement of element, especially the coupling of power tube requires lowly, can simplify technology and reduce cost.

Figure of description is a circuit diagram of the present utility model.Among the figure: I, I are tube load.

When the utility model is implemented, should consider power tube V ₁, V ₂Withstand voltage and power with the designing requirement of adaptive circuit.IC ₁-IC ₅Adopt the hex inverter of integrated circuit Schmidt input.

Claims

1, a kind of high efficiency fluorescent lamp supply convertor comprises band anti-noise filter and unilateral diode (D ₁) and pressurizer (R ₁, D ₂) dc power supply that constitutes, it is characterized in that by integrated circuit (IC ₁), resistance (R ₂), capacitor (C ₃) multivibrator that constitutes, its output inserts by integrated circuit (IC ₂) inverter that constitutes, inverter output respectively with by integrated circuit (IC ₃, IC ₅) constitute the rising edge monostable flipflop, by integrated circuit (IC ₄) control end of the trailing edge monostable flipflop that constitutes links and forms the Pulse-trigger control switching circuit, Pulse-trigger control switching circuit output respectively with VMOS high power valve (V ₁, V ₂), the control grid of the AC power output amplifier formed of transformer (B) links the secondary (N of transformer (B) ₃) on, in parallel at least one group by an inductor and three LC series resonant tank that capacitor constitutes.