CN2529487Y - Fluorescent lamp electronic ballast - Google Patents

Abstract

The utility model discloses a fluorescent lamp electronic ballast which belongs to the technical field of electric lightening for lightering and power supply through high frequency electricity. The utility model impedes the relatively high charged electricity current when starting the machines while using a slipstream circuit or a sourced filtering circuit through connecting the paralleled unit of an inductor L2 and a capacitance C1 and the paralleled unit of an electric resistor R1 and a reed pipe J in series with the back part of a ballasting bridge. And though connecting a neon tube in parallel between a feedback electric inducting coil and partial ballasting inducting coil, and connecting an electric feeding AC input terminal in series with the inductor L1, the utility model also is used when an N tube does not work bu lightens under normal circumstance. Under abnormal circumstance that he N tube glow discharges and switches off, and then the utility model limits the electricity current on the feedback and ballasting coil to certain value till zero; in addition, the load of the power tube is very low. When the N tube switches from switching off to switching on, the harmful pulse is impeded due to the effect of L1 at the short period. Finally, the utility model achieves to the protection on cost abnormality and protection on machine starting impacting electricity current.

Description

A kind of electronic ballast for fluoresent lamp

Technical field

A kind of electronic ballast for fluoresent lamp of the utility model relates to and the electric lighting technology, and concrete is to belong to a kind of circuit arrangement that is used for discharge lamp igniting or control, wherein by high-frequency alternating current lamp is lighted a fire and powered operation.

Background technology

Fluorescent lamp (HD) electric ballast roughly has following three parts on principle, i.e. (1) anti-electromagnetic interference and current rectifying and wave filtering circuit; (2) circuit of power factor correction; (3) HF power conversion device.On above-mentioned (2) this problem the employing partially-filtered Circuit is arranged, the current follow-up circuit of being called is also arranged, power factor (PF) can reach more than 90%.More take active filter, can obtain very level and smooth and the direct voltage of rule, as long as suitably control, input current just becomes sine wave.But all have a technical problem in these two schemes, promptly be lower than under the input voltage situation at output voltage and start shooting, impulse current is very big.(foregoing is seen 1998 the 1st 22 pages of the phases " enlightenment of Motorola's electric ballast " of Chinese electric lighting, 1998 the 2nd phases 24 pages " reducing the circuit of fluorescent lamp electronic ballast of harmonic wave ").The electric ballast of 92,208,994 1 kinds of charged source input protections of utility model has proposed exchanging resistance of series connection on the incoming line before the rectifier bridge; electric capacity in parallel between two lines then; resistance is at 0.5 Ω-20 Ω, capacitor's capacity 〉=1000Pf; big electric current when starting to reach effective inhibition can prevent that also the electrical network high-voltage pulse from puncturing.Blemish in an otherwise perfect thing be this resistance consumed power and become pyrotoxin in vain always.The high-frequency electronic ballast of utility model 90207790 anti-surge voltages has proposed exchanging inductance of series connection on the incoming line before the rectifier bridge, inductance value is 0.3-1mH, can resist 2 kilovolts of-2.5 kilovolts of external circuit surge voltages, make that voltage obviously descends on the filter capacitor, play the anti-effect of resistance.In addition, the HD electric ballast also should have abnormal state protection circuit, and negative electrode fracture of wire and the lamp of standing professional standard at least can not start two tests.(foregoing is seen " household electrical appliance 4 phases of nineteen ninety-five the 10th page the 11st page " to the observation and the thinking in electric ballast market " ") 97,223,685 1 kinds of electric ballasts with the neon tube protector for abnormal condition of utility model have proposed at the HF power conversion device by outputting inductance L1; through ballast inductance L2 signal is delivered to the filament leading foot of fluorescent lamp HD again; again on starting capacitor this basis in parallel of each leading foot of the filament another side that is connected across the fluorescent tube two ends with a semistor; the two ends of starting capacitor also will be parallel with a neon tube N who has the bimetal leaf contact as protector for abnormal condition again, and this neon tube is unloaded down from fluorescence lamp starter.In case its protection philosophy is abnormality to occur, damage such as fluorescent tube HD, or because of quality not good; though be preheated and starting capacitor C both end voltage raises at filament; and fluorescent tube HD be can not light the time, in the case, if when starting capacitor C both end voltage continues to be increased to the starting voltage value of neon tube N; neon tube N starter; output loading resonance departs from, and the C drops that powers on is when the N starter and through certain hour t after promptly 0.2 second to 1 second; the N closure, the C short circuit dischange.Through certain closing time promptly after 30 seconds to 60 seconds N cooling back disconnect, the last voltage of C is again from liter above freezing, needs only pipe and do not change and continue said process.Electric ballast has obtained protection like this.Blemish in an otherwise perfect thing be that it is not that good HD eliminates that at first this protection can make some quality, and through test, wherein some such pipe can be lighted with the method for the power of strengthen lighting a fire.Secondly be that output frequency descends and causes ballast inductance induction reactance to reduce under the short-circuit conditions in the N closure, alternating voltage adds again thereon, the effect of the magnetic core magnetic saturation working point of ballast inductance skew is in addition flow through two triode electric currents of this grade and is higher than the normal value of lamp when bright.Two not failures of oscillations of triode this moment, test shows instantaneous sample power surpasses 10W.The life-span of triode can shorten damage even in this case.

Summary of the invention

In view of this; the utility model proposes a kind of electronic ballast for fluoresent lamp, its technical problem that will solve is that the startup impulse current is reduced, and skilful use neon tube abnormal protection device but to make flow through pipe electric current still less; simultaneously, some so-called aging HD still can be lighted.Technical solutions of the utility model are: first technical measures are to set up a series connection resistance after rectifier bridge, and in resistance two ends parallel connection one in reed pipe, at a magnet exciting coil and the assembly after electric capacity is in parallel of connecting again before the resistance.Second technical measures: at outputting inductance is the input of feedback inductance coil and at ballast inductance coil a discharger in parallel such as neon tube from the tapping point of its input meter number of turns less than certain coil determined of half, rather than at the starting capacitor two ends neon tube in parallel.The inductance of the series connection of ac input end before rectifier bridge that adapts.From first measure, the big electric current during start is subjected to resistance to be suppressed, and especially during the peak values of ac input, very fast afterwards resistance is by the short circuit of tongue tube institute, thereby finishes the soft start time-lag action.From second measure, behind HF power conversion device output square-wave pulse, when the voltage that reaches certain HD, lamp is bright.Be t1 during this period of time, should be very short.If it is not bright, this moment, the N pipe promptly entered the aura period, about 1 second of this t2 or more, can be considered resistance in parallel again on feedback coil and the part ballast inductance, this moment, pulse voltage was subjected to significant limitation, voltage on feedback coil and the ballast coil is more than 1 times of glow voltage of N pipe, and the difference that this value deducts 155 volts of voltages on the triode is the magnitude of voltage that is added in the starting capacitor two ends, and this value is also not really high.The N pipe is closed after the t2, and after t3 promptly 3 seconds-6 seconds, the N sheet flicks, and returns to the initialization state.In this period, feedback and part ballast coil are by the N tube short circuit, though there is the dc supply vibration to stop not work on the triode at t3.When flicking moment,, can not produce the rush of current of certain harmful frequency because ac input end seals in inductance.Repeat the t1 section again during the time, this moment, actual measurement showed that the pipe that has can be lighted, or also might light through several cycles again because the power summation of previous cycle to HD arranged.The contrast prior art, clearly, during abnormal protection, the electric ballast operating current is very little, even has the long period to equal zero.Because t2, t3 are longer, go round and begin again to be in for a long time like this under the abnormal protection and use.Pertinent regulations according to " the light fixture safety requirements passes through teaching material with the mandatory national standard of test a surname " of writing by China Commission of Certified Electrical Products's standard coordination place tissue in August, 1997, should select the harshest the 5th kind for use to electric ballast in 5 kinds of unusual circuit is that fluorescent tube does not start, but two unspoiled situations of electrode are tested, method is to connect corresponding artifical resistance at ballast output end, i.e. two 5 Ω resistance wires.Test show the utility model under 250V through 24 hours, touch ballast iron shell with hand, do not have any intensification, similar with 10 ℃ of room temperatures.

Description of drawings

Fig. 1 is to use the utility model electronic ballast for fluoresent lamp electrical schematic diagram of partially-filtered Circuit.

Fig. 2 is to use the utility model electronic ballast for fluoresent lamp electrical schematic diagram of active power filtering.

Embodiment

From Fig. 1, seal in an inductance L 1 at the civil power ac input end, be used in machine taking place under the particular case, transfer to from closure state as the N pipe and flicking in a flash, the external circuit input current is increased severely and when just being sinusoidal peak value, can on L1, be stabilized.Behind the D1-D4 rectifier bridge, seal in the part in parallel of magnet exciting coil L2 and filter capacitor C1 again, and the part in parallel of time-delay soft start resistance R 1 and tongue tube J, when to be used to make start especially just be sinusoidal peak value moment, flow through rectifier bridge and the charging current of filter capacitor C2 and C3 stabilized on R1, under L2 and C1 effect, J connects R1 by short circuit afterwards.By capacitor C 2, C3 and diode D5, D6, D7 component part filter circuit, output forward pulsation peak value is that 310 volts direct current uses for the back level.The back level is the HF power conversion circuit; also include the neon tube abnormity protection circuit; it is by triode VT1, VT2; and on same magnetic core three groups only a small amount of several circles output or claim feedback inductance coil L3-1, L3-2, L3-3; and ballast inductance L4 and fluorescent tube HD and charge and discharge capacitance C6, starting capacitor C7 composition.Neon tube N is connected across between L3-2 input and the part ballast inductance L4, and promptly an end is on the 2nd tapping point on the L4, from an embodiment, point was 50 circles from No. 1 o'clock to No. 2 on the L4 coil, point was 75 circles from No. 2 o'clock to No. 3, and L4 is 125 circles altogether, between the N pipe cross-over connection 1 o'clock to 2 o'clock.No. 2 points generally change about half at L4 coil sum.When fluorescent tube HD normally lights, its current circuit has two, first is: from positive source → C6 charging → filament HD1 → through HD pipe → filament HD2 → ballast inductance L4 → feedback inductance L3-2 → VT2 conducting → power cathode, another is: C6 discharge → VT1 conducting → L3-2 → L4 → filament HD2 → and through HD pipe → filament HD1 → C6.When abnormality occurring, be that the normal and C7 of filament goes up voltage and increases severely, then the last voltage of L4 also rises, when L on the L4 o'clock between No. 2 voltage rise to when making N pipe starter, if when setting 190V, the last voltage of L4 is 475V, and C7 to go up voltage be the poor of L4 155 volts of mid-point voltages going up voltage and triode, be 320V.L4 and C7 go up voltage and have been subjected to the protectiveness restriction.N closure after aura finishes, L3-2 coil be by short circuit, no feedback signal, and triode VT does not work.When the N pipe flicks at that moment from being closed into,, L4 coil and other distributed capacitance effects stabilized because of the L1 coil is arranged owing to producing instantaneous large-current.

From Fig. 2, contrast Fig. 1, difference only changes over partially-filtered Circuit the active filter circuit of being made up of energy storage coil L5, D8, VT3, switch feedback signal coil L3-4, C8, and L3-1, L3-2, L3-3 are on same magnetic core among coil L3-4 and Fig. 1.Other there is no principle and change.Can be used as another kind of execution mode.

Claims (2)

1, a kind of electronic ballast for fluoresent lamp comprises the rectifier bridge that civil power is imported, and circuit of power factor correction is connected with the neon tube protector for abnormal condition in HF power conversion circuit and the output circuit thereof, it is characterized in that:

(1) also is included in the part in parallel that is in series with after the rectifier bridge between magnet exciting coil and the filter capacitor and the part in parallel between series resistance and the tongue tube more afterwards, thereby forms the soft start delay circuit;

(2) the described neon tube protector for abnormal condition that is connected with is meant that the input endpoint at the feedback coil of exporting is on the part ballast coil to the tapping point of coil somewhere, ballast inductance, be parallel with a neon tube; Also can connect into an inductance at the civil power ac input end.

2, a kind of electronic ballast for fluoresent lamp according to claim 1 is characterized in that on the tapping point of coil somewhere, described ballast inductance, can be to count the 50th circle from its input to determine tapping point, and the number of turns of remaining ballast inductance coil is 75 circles.

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