CN2147711Y - Electronic ballast - Google Patents

Abstract

The utility model relates to an electronic ballast. A harmonic distortion decreasing circuit and an abnormal state protection circuit are additionally arranged on the basis of the original circuit. The former is realized through the network which is composed of capacitors, resistors and diodes, and the latter is realized by making use of the induction coil coupled on the choke coil in a resonating circuit to feed back abnormal state signals to the circuit which is composed of switch transistors and double-contact electric relays. In addition, the induction coil and the network which is composed of the electric relay form a preheat circuit through a 555 time-base integrated circuit. The utility model has the advantages of reasonable structure, high safety, long service life and high power factor.

Description

Electronic ballast

The utility model relates to a kind of circuit arrangement that is used for fluorescent lamp starter and ballast, belongs to the circuit arrangement class of electrolighting.

At present common electric ballast is mainly by current rectifying and wave filtering circuit, composition such as high-frequency oscillating circuits and load resonant circuit, current rectifying and wave filtering circuit is made of full wave bridge rectifier and filter capacitor, and after current rectifying and wave filtering circuit, be connected to by positive feedback auto-excitation type pulse transformer B and two higher-order of oscillation switching circuits that transistor constitutes, the frequency of oscillation of this circuit is generally between 20KHZ～50KHZ.After the higher-order of oscillation switching circuit its output be connected to choke and connect fluorescent tube two end-coils (load) thereby and resonant capacitance constituted load resonant circuit, this resonant circuit makes fluorescent lamp high pressure starter, and choke just plays the ballast effect behind the starter.Though the electric ballast of this structure is simple in structure; cost is also lower; but there is following several problem from the situation of practical application: the first, poor reliability; only be to satisfy the requirement of starter and ballast because of the electric ballast of this structure; and do not have a protective device of overvoltage, overcurrent or abnormality, when fluorescent lamp, often produces bigger electric current whole electric ballast is burnt can not starter the time because of aging; so useful life is short, brings difficulty for applying.The second, the electric ballast harmonic distortion of said structure is big, and its harmonic component does not reach the triple-frequency harmonics stipulated in the ZBK74012-90 standard of country promulgation less than first-harmonic 30 λ %(λ: power factor (PF)) and second harmonic less than the requirement of first-harmonic 5%.And harmonic content is too big, not only causes the interference to electrical network to increase, and the line power factor reduces, and more serious meeting influences the safe operation of electric ballast and power supply network.Three, existing this electric ballast belongs to quick cold starter mode to the starter of fluorescent lamp, and homemade straight-pipe fluorescent lamp almost all belongs to the preheating cathode formula, when being carried out starter, this homemade straight-pipe fluorescent lamp requires to carry out filament pre-heating earlier, and then high pressure starter, otherwise will accelerate coming off of Filament of fluorescent lamp surface triplex carbonate thermionic emission material, the lamp tube ends blackout is accelerated, influence the useful life of fluorescent lamp.Four, the power factor (PF) of whole circuit is low, generally has only about 0.6.

The purpose of this utility model is in order to overcome the deficiency of above-mentioned existence, and provides a kind of safe and reliable, can prolong the useful life of fluorescent lamp, improves the electric ballast of power factor (PF).

The purpose of this utility model is finished by following technical solution, promptly is connected to reduce the harmonic distortion circuit between current rectifying and wave filtering circuit and higher-order of oscillation switching circuit, and it is by capacitor C ₂, resistance R ₃, diode V ₅, resistance R ₄, capacitor C ₃Successively the series connection and at C ₂, R ₃, V ₅, R ₄And R ₃, V ₅, R ₄, C ₃Two ends each and be connected to diode V ₇And V ₆Constitute; Be equipped with abnormal state protection circuit on higher-order of oscillation switching circuit, its formation is to establish one group of resistance-capacitance depressurization and current rectifying and wave filtering circuit in addition, and its output is parallel with voltage-stabiliser tube V respectively ₂₅With double-contact relay K ₂, normally opened contact KJ ₂₁Two groups of loops of series connection are at normally opened contact KJ ₂₁Two ends be connected to triode V ₂₆CE knot, and B knot serial connection voltage-stabiliser tube V ₁₄And resistance R ₁₂A full wave bridge rectifier V is passed through with the E knot in the back ₁₇～V ₂₀Be connected to and choke W ₁The induction coil W of coupling ₂, this abnormal state protection circuit is by normally opened contact KJ to the effect of higher-order of oscillation switching circuit ₂₂Be parallel to switching tube V in the higher-order of oscillation switching circuit ₁₂BE knot between realize.

The utility model is at described full wave bridge rectifier V ₁₇～V ₂₀The back also is connected to preheating starting circuit, and it is mainly by 555 time-base integrated circuits and relay K ₁Constitute, by resistance R ₁₄And capacitor C ₉The series connection back is inserted at full wave bridge rectifier V ₁₇～V ₂₀Output, 6 and 2 ends and 1 end of 555 time-base integrated circuits are parallel to capacitor C ₉Two ends, and 3 ends are being connected to relay K ₁After respectively with 4 ends, 8 ends and resistance R ₁₄The f point join and relay K ₁Normally-closed contact KJ ₁Be parallel to capacitor C in the load resonant circuit ₁₀Two ends.

The utility model also is connected to piezo-resistance R at the input of circuit ₁, fuse F ₁And rfi filter T ₁, play effects such as overvoltage, overcurrent and inhibition radio frequency interference.

Description of drawings is as follows:

Fig. 1 is a structural representation of the present utility model.

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

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

Below will the utility model is further introduced by accompanying drawing, Fig. 1, electron rectifier has a housing that is rectangle 1, base 2 is arranged below, there is installing hole 3 at the two ends of base 2, the both sides of housing 1 are provided with input and output wiring hole 4, and in housing 1, be mounted with constitute below the electronic building brick 5 of described circuit.Fig. 2; circuit of the present utility model is by over-voltage over-current protection circuit 6; current rectifying and wave filtering circuit 7; higher-order of oscillation switching circuit 8, load resonant circuit 9 reduces harmonic distortion circuit 10; abnormal state protection circuit 11; preheating starting circuit 12 and load 13 are formed, and the physical circuit principle is seen Fig. 3, is connected to fuse F at circuit input end ₁, piezo-resistance R ₁And rfi filter T ₁Constitute over-voltage over-current protection circuit 6, played the over-voltage over-current protection effect, also suppressed radio frequency interference simultaneously; Be connected to current rectifying and wave filtering circuit 7 after this over-voltage over-current protection circuit 6, its all-wave is by bridge rectifier V ₁～V ₄Form full wave bridge rectifier V ₁～V ₄Two outputs and be connected to by capacitor C ₂, resistance R ₃, voltage-stabiliser tube V ₅, resistance R ₄, capacitor C ₃Successively the series connection and at C ₂, R ₃, V ₅, R ₄And R ₃, V ₅, R ₄, C ₃Two ends are parallel with diode V respectively ₇And V ₆The reduction harmonic distortion circuit 10 that is constituted, adding above-mentioned reduction harmonic distortion circuit 10 before higher-order of oscillation switching circuit 8 can make harmonic distortion be effectively controlled, power factor (PF) is improved greatly, general its power factor (PF) can reach about 0.95, the functional reliability of using improves, its operation principle is: at the positive half cycle of input voltage, when input terminal voltage Ucd greater than bridge rectifier V ₁～V ₄During output Uab voltage, obvious V ₁And V ₃Conducting, anodal input current i is non-vanishing, and electric network source directly gives higher-order of oscillation switching circuit 8 power supplies, and output current is to electrochemical capacitor C simultaneously ₂And C ₃Charge, and they are charged to higher value, when charging finishes, diode V ₅Bearing bigger reverse voltage, when Ucd=Uab, capacitor C ₂And C ₃Do not begin discharge, along with the decline of the positive half cycle magnitude of voltage of Ucd, Uab also descends, but capacitor C ₂And C ₃The two ends pressure drop still remain unchanged and diode V ₅The back-pressure of bearing begins to reduce, and at this moment electrical network still passes through diode V ₁And V ₃To higher-order of oscillation switching circuit power supply, this moment i=0, when Ucd continues to reduce and diode V ₅When the back-pressure of bearing is reduced to zero, diode V ₁And V ₃End capacitor C ₂Through diode V ₆, capacitor C ₃Through V ₇Give the higher-order of oscillation switching circuit power supply of back simultaneously, when line voltage oppositely and its absolute value when surpassing Uab, diode V ₂And V ₄Conducting, the value of i is non-vanishing again, therefore owing to adopted above-mentioned resistance, the network that electric capacity and diode constitute carries out filtering, the non-zero-time of power network current i is increased greatly, and its waveform is compared with the current waveform of prior art, more approaches sine wave, thereby significantly reduced higher harmonic components, the summation of all high-frequency harmonics also has only about 22% of fundametal compoment.Foregoing circuit also plays a part filtering simultaneously, has therefore cancelled the filter capacitor of original independent setting.

After above-mentioned reduction harmonic distortion circuit 10 and be connected to higher-order of oscillation switching circuit 8, it is by positive feedback auto-excitation type pulse transformer B, triode V ₁₂And V ₁₃, capacitor C ₄～C ₇, resistance R ₅～R ₁₁, diode V ₈～V ₁₁Deng composition, export higher-order of oscillation electric currents via choke W by these higher-order of oscillation switching circuit 8 backs ₁And capacitor C ₁₀The resonant circuit 9 that is constituted makes fluorescent lamp high pressure starter, and above-described higher-order of oscillation switching circuit 8 is basic identical with load resonant circuit 9 and prior art, no longer is described in detail at this.

Find that in to the practical application of existing electric ballast fluorescent lamp can not starter because of problem such as aging, just easily ballast burnt this moment that the utility model has been set up abnormal state protection circuit 11 in circuit for this reason.It is at full wave bridge rectifier V ₁～V ₄Be parallel with another group resistance-capacitance depressurization and bridge rectifier, at this full wave bridge rectifier V before ₂₁～V ₂₄Output be parallel with voltage-stabiliser tube V ₂₅With double-contact relay K ₂With normally opened contact KJ ₂₁Two groups of loops of series connection are at normally opened contact KJ ₂₁Two ends and be connected to triode V ₂₆BE knot, and V ₂₆B knot pass through resistance R ₁₂With voltage-stabiliser tube V ₁₄Serial connection and be connected to bridge rectifier V ₁₇～V ₂₀Respective end, E knot is access V directly ₁₇～V ₂₀Another respective end, bridge rectifier V ₁₇～V ₂₀Two terminate at and choke W in addition ₁The induction coil W of coupling ₂On.While another normally opened contact KJ ₂₂Be connected in parallel on triode V in the higher-order of oscillation switching circuit 8 ₁₂BE knot between.Its operation principle is that the 220V alternating voltage is through resistance R ₂And capacitor C ₁Resistance-capacitance depressurization and bridge rectifier V ₂₁～V ₂₄Rectification, capacitor C ₁₁After the filtering, voltage stabilizing didoe V is given in power supply ₂₅With double-contact relay K ₂Work.During the ballast operate as normal, Ue ≈ 12V, and voltage stabilizing didoe V ₁₄Value more than 20V, so V ₁₄With diode V ₂₆All can not conducting, relay K ₂Also can't move, when abnormality appears in fluorescent tube (fluorescent lamp can not starter, rectifying effect promptly occurs or goes to swash the method effect), induction coil W ₂Will sense the higher voltage value, through rectifier V ₁₇～V ₂₀Can produce a high voltage at output after the rectification, make V ₁₄Conducting, triode V ₂₆Obtain bias current and conducting, relay K ₂Must be electric, two normally opened contact closures, wherein normally opened contact KJ ₂₂Closure makes higher-order of oscillation switching circuit failure of oscillation, thereby this circuit is worked; Another group normally opened contact KJ ₂₁Closure makes relay K ₂Self-locking, thus prevented the starting of oscillation once more of circuit, get rid of abnormality after, ballast and fluorescent lamp can continue operate as normal.

At described bridge rectifier V ₁₇～V ₂₀Afterwards and be connected with preheating starting circuit 12, promptly be connected to by resistance R at two outputs ₁₄And capacitor C ₉The loop of series connection is connected into the monostable mode with 555 time-base integrated circuits, and its 6 and 2 end and 1 end are parallel to capacitor C respectively ₉Two ends, 3 terminations have relay K ₁After be connected on integrated circuit 4 ends, 8 ends and resistance R respectively ₁₄The f point, and relay K ₁Normally-closed contact KJ ₁Be parallel to capacitor C in the load resonant circuit 9 ₁₀Two ends.Its operation principle is: when connecting main circuit power, by the power supply of higher-order of oscillation switching circuit output through choke W ₁, load 13(filament) and relay K ₁Normally-closed contact KJ ₁Form the loop, simultaneously choke W ₁The high-frequency voltage signal at two ends also is coupled to induction coil W ₂Two ends, this induced voltage is through V ₁₇～V ₂₀Full-wave bridge rectifier and capacitor C ₈Filtering, resistance R ₁₃Current limliting step-down and voltage stabilizing didoe V ₁₅Voltage stabilizing obtains the direct voltage of about 10V and supplies with 555 time-base integrated circuits and relay J ₁Make direct-current working volts.Rigidly connect when leading to main circuit power capacitor C ₉The two ends pressure drop be zero, 3 ends of 555 time-base integrated circuits are output as high level, relay K ₁Be failure to actuate normally-closed contact KJ ₁Keep normally closedly, fluorescent lamp can not starter, carries out preheating but electric current then flows through filament.Working direct current is to capacitor C subsequently ₉Charging, the voltage at its two ends raises gradually, when rise to direct-current working volts 2/3 the time, 555 time-base integrated circuits counter-rotatings, 3 ends are output as low level, relay K ₁Get electric adhesive, normally-closed contact KJ ₁Disconnect choke W ₁And capacitor C ₁₀Form series resonance, C ₁₀The high pressure at two ends is added in the fluorescent tube two ends and makes the interior argon gas ionization of fluorescent lamp, tube starting, and behind the starter, circuit off resonance, choke W ₁Play the ballast effect, above-mentioned warm-up time is by resistance R ₁₄And capacitor C ₉Value decision.

If with above-described choke and connect and be two or several and be connected in series with corresponding resonant capacitance separately and form two or several resonant circuits in parallel, at this moment control two or many fluorescent tubes with regard to an available electric ballast.Correspondingly on the choke of parallel connection, be coupled with corresponding induction coil and, can make abnormal state protection circuit 11 and preheating starting circuit 12 operate as normal by the output in parallel of full-bridge bridge rectifier separately.

Among Fig. 3, R ₁=470K, R ₂=2M, R ₃=R ₄=20 Ω, R ₅=680K, R ₆=R ₇=100 Ω, R ₈=R ₉=5.1 Ω, R ₁₀=R ₁₁=0.5 Ω, R ₁₂=3.3K, R ₁₃=100 Ω, R ₁₄=51K, C ₁=0.68 μ, C ₂=C ₃=4.7 μ, C ₄=0.022 μ, C ₅=6800P, C ₆=C ₇=0.1 μ, C ₈=100 μ, C ₉=47 μ, C ₁₀=0.015 μ, V ₁～V ₈Be 1N4007 diode, V ₉Be 1N4148 diode, V ₁₀Be DB3 bidirectional diode, V ₁₁Be 1N4148 diode, V ₁₂And V ₁₃Be MJE13005 triode, V ₁₄Be 35V voltage stabilizing didoe, V ₁₅Be 10V voltage stabilizing didoe, V ₁₆～V ₂₄Be 1N4007 diode, V ₂₅Be 11V voltage stabilizing didoe, V ₂₆Be 9013 triodes, F ₁Be 1A fuse, T ₁Be rfi filter, wherein W ₁=W ₂=10 circles, T ₂Be chokes induction coil winding, wherein W ₃=100 circles, W ₄=6 circles, B are positive feedback auto-excitation type pulse transformer, its L1a=L1b=5 circle, L1c=9 circle, IC ₁Be NE555C time-base integrated circuit, K ₁Be 4098 single contact relays, K ₂Be 4099 double-contact relays, LAMP is a fluorescent tube.

The utility model compared with prior art, have rational in infrastructure, safe and reliable, can prolong the service life of fluorescent lamp, power factor (PF) height, economize on electricity, the excellent characteristics of Universal electric performance, be a kind of national standard that meets, easy to utilize, the efficient Full functional electronic ballast of obvious economic and social benefit is arranged.

Claims (3)

1, a kind of electric ballast includes a housing and settles its interior electronic building brick such as current rectifying and wave filtering circuit, higher-order of oscillation switching circuit and load resonant circuit, it is characterized in that:

A, between current rectifying and wave filtering circuit (7) and higher-order of oscillation switching circuit (8) and be connected to and reduce harmonic distortion circuit (10), it is by capacitor C ₂, resistance R ₃, diode V ₅, resistance R ₄, capacitor C ₃Be connected in series successively, and at C ₂, R ₃, V ₅, R ₄And R ₃, V ₅, R ₄, C ₃Two ends each and be connected to diode V ₇And V ₆Constitute;

B, be equipped with abnormal state protection circuit (11) on higher-order of oscillation switching circuit (8), its formation is: other establishes one group of rectifier filter, and its output is parallel with voltage-stabiliser tube V respectively ₂₅With double-contact relay K ₂With normally opened contact KJ ₂₁Two groups of loops of series connection are at normally opened contact KJ ₂₁Two ends be connected to triode V ₂₆, this triode V ₂₆B knot serial connection voltage-stabiliser tube V ₁₄Full wave bridge rectifier V is passed through with the E knot in the back ₁₇～V ₂₀Be connected to and choke W ₁The induction coil W of coupling ₂, another normally opened contact KJ ₂₂Be connected in parallel on switching tube V in the higher-order of oscillation switching circuit (8) ₁₂BE knot between.

2, electric ballast as claimed in claim 1 is characterized in that described full wave bridge rectifier V ₁₇～V ₂₀The back also is connected to preheating starting circuit (12), and it is mainly by 555 time-base integrated circuits and relay K ₁Constitute, by resistance R ₁₄And capacitor C ₉The series connection back is inserted at V ₁₇～V ₂₀Output, 6 and 2 ends and 1 end of integrated circuit are parallel to capacitor C respectively ₉Two ends, and 3 ends are being connected to relay K ₁After respectively with 4 ends, 8 ends and resistance R ₁₄The f point join relay K ₁Normally-closed contact KJ ₁Be parallel to capacitor C in the load resonant circuit (9) ₁₀Two ends.

3, electric ballast as claimed in claim 1 or 2 is characterized in that described circuit input end is connected to piezo-resistance R ₁, fuse F ₁And rfi filter T ₁

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