CN2132381Y

CN2132381Y - High power electronic ballast with preheating protective function

Info

Publication number: CN2132381Y
Application number: CN 92230404
Authority: CN
Inventors: 葛少明
Original assignee: EZHOU CLOCK FACTORY
Current assignee: EZHOU CLOCK FACTORY
Priority date: 1992-08-21
Filing date: 1992-08-21
Publication date: 1993-05-05
Anticipated expiration: 2002-08-21

Abstract

The utility model relates to an improved electronic ballast with high power factors, which is composed of a rectifying filter circuit, an inverter circuit, a filament preheating circuit and a protective circuit. The input end of the rectifying bridge of the rectifying filter circuit is connected with an 220V AC power supply, and the output end of the rectifying bridge of the rectifying filter circuit is connected with the input end of the power supply of the inverter circuit; the output end of the inverter circuit is provided with conductor wires which are used for connecting with the lamp filaments at both ends of a lamp tube, and the output end of the filament preheating circuit is provided with another two conductor wires which are used for connecting with the lamp filaments at both ends of the lamp tube. The utility model has the advantages of simple structure, complete function, high power factor, low harmonic content and low electric pollution; the filament preheating circuit works reliably, the protective circuit acts sensitively, and thus the service life can be ensured and the service life of the lamp tube can be extended.

Description

High power electronic ballast with preheating protective function

The utility model relates to the electroporation field, the high power factor electric ballast of specifically a kind of improved prolongation fluorescent tube and ballast life.

At present, research and produce electric ballast, various in style, but that ubiquity useful life is short, comprise that institute joins fluorescent tube and ballast self, the harmonic content height, problem such as power factor (PF) is low, thereby can't popularize.The fluorescent tube short electric ballast that is in useful life does not mostly possess the preceding filament warm of starter, even notice this kind problem, electric ballast as the production of the plumbous net in Ezhou, Hubei Province factory, design has filament preheating circuit, but it adopts the switch transition of miniature circuit breaker as the preheating starter, has the voltage adaptation narrow range, especially relay sticky point problem, short problem of life-span does not still intactly solve.In addition, existing electronic ballast lacks the self-protection function, causes the useful life of electric ballast self short, and its protective value comprises two aspects in fact, and the one, the protective capability when using power supply to surpass the scope of application; The 2nd, when fluorescent tube uses its end-of-life, a kind of " abnormality " takes place, fluorescent tube internal starting material funeral this moment to the greatest extent, tube filament is intact, two ends apply high pressure, can not starters, like this, the power of whole fluorescent tube is reflected on the electric ballast, and electric current sharply increases and electric ballast is burnt.That CN89221411.2 discloses is a kind of " electric ballast with modified model protective device; its design is mainly by high tension protection circuit with prevent that continuous starting circuit from forming; high tension protection circuit is made up of diode, two-way trigger tube, protection switch pipe and resistance, electric capacity; this circuit for intermittence protective circuit very unreliable; and have only supply voltage and work when too high, invalid unusually to fluorescent tube.CN88206350.2 also discloses a kind of electronic ballast for fluoresent lamp with overcurrent protection; it has mainly adopted relay to carry out overcurrent protection; because it is short that relay exists useful life; move defectives such as unreliable, insensitive and voltage adaptation narrow range; equally also only supply voltage is worked when unusual, and invalid when unusual to fluorescent tube.

The purpose of this utility model provides a kind of multiple functional, has filament pre-heating and automatic protection functions, the high power factor electric ballast that harmonic content is low are arranged when power supply and fluorescent tube abnormality.

The utility model is made up of current rectifying and wave filtering circuit, inverter circuit, filament preheating circuit and protective circuit.The input termination 220V AC power joint of the rectifier bridge in the current rectifying and wave filtering circuit; the output of current rectifying and wave filtering circuit is connected with the inverter circuit power input; output in the inverter circuit connects fluorescent tube two ends wire filament; the output of filament preheating circuit has two leads in addition that connect fluorescent lamp two ends filament; filter circuit in the current rectifying and wave filtering circuit is by diode D3; D4; D7 and capacitor C 0; electrochemical capacitor C1; C2 constitutes; the positive pole of rectifier bridge is connected with D3 negative pole and C1 positive pole; the rectifier bridge negative pole is connected with D7 positive pole and C2 negative pole; D3 is anodal to be connected with the anodal D4 negative pole of C2; D4 is anodal to be connected with C1 negative pole and D7 negative pole; C0 is connected in parallel on the both positive and negative polarity of rectifier bridge output; filament preheating circuit is formed by controllable silicon 3CT1 and for 3CT1 provides the delay circuit and the power circuit that trigger time delayed turn-off; the 3CT1 first anode; second plate is drawn the lead that connects tube filament respectively; the output of delay circuit connects the trigger electrode of 3CT1; protective circuit is formed by one-way SCR 3CT2 and for 3CT2 provides the delay trigger circuit and the power circuit of time-delay trigger current; the resistance R 8 of 3CT2 negative electrode in preheat circuit connects the 3CT1 control utmost point, anode contact energy source.

Wherein, filament preheating circuit also can be made up of rectifier bridge and one-way SCR, the input of rectifier bridge has the lead-out wire that connects the fluorescent lamp tube filament, and the output head anode order of rectifier bridge is to the controllable silicon anode, and the rectification bridge output end negative pole connects delay circuit ground wire (negative pole) in the preheat circuit.

Filament preheating circuit can also be by two one-way SCRs; two diodes and the delay circuit composition that trigger current is provided for two controllable silicons; the anode of two one-way SCRs has the lead-out wire that connects fluorescent tube two ends filament respectively; the negative pole of two diodes is connected with the anode of two one-way SCRs respectively; the positive pole of two diodes connects the negative pole of preheat circuit; filament preheating circuit can also be made of and protective circuit is formed by one-way SCR with for one-way SCR provides delay trigger circuit and power circuit a thermo-sensitive resistor element; the one-way SCR anode connects the direct current output cathode of current rectifying and wave filtering circuit; negative electrode is through resistance; be connected with transistor base behind the capacity cell; the collector electrode of this triode connects the transistor base in the inverter circuit, and emitter connects the direct current output negative pole of current rectifying and wave filtering circuit.

Because filament preheating circuit reliable operation of the present utility model; pre-heat effect is good; thereby prolonged fluorescent tube useful life; its protective circuit is active in one's movements reliably, has guaranteed the utility model useful life, and its power factor (PF) is more than 0.9; reduced harmonic content largely; reduced electropollution, it is multiple functional, and circuit structure is simple.

Describe in detail below in conjunction with the utility model embodiment accompanying drawing:

Figure one the utility model embodiment 1 circuit diagram

Figure two the utility model embodiment 2 circuit diagrams

Figure three the utility model embodiment 3 circuit diagrams

Figure four the utility model embodiment 4 circuit diagrams

Embodiment 1

Shown in figure one, the filter circuit that the rectifier bridge that current rectifying and wave filtering circuit 1 is made up of diode D1, D2, D5, D6 and diode D3, D4, D7 and electrochemical capacitor C1, C2, polarity free capacitor C0 form is formed.The rectifier bridge input inserts the lead of 220V AC power, its output head anode and D3 negative pole, and C1 is anodal to be connected; Negative pole of output end and D7 positive pole, the C2 negative pole connects, and C0 is attempted by between the output positive and negative charge.Inverter circuit 2 is common resonant circuit.It is by triode BG1, BG2, trigger tube DB diode D8, and capacitor C 4, C5, oscillator coil B1, inductance coil L1 and resistance R 1-R6 form, and the input power supply is connected with the rectifying and wave-filtering output.The output of inverter circuit 2 has the lead that connects fluorescent tube W filament two ends.Filament preheating circuit 3 is formed by bidirectional triode thyristor 3CT1 with for 3CT1 provides the delay circuit and the power circuit that trigger time delayed turn-off.Its delay circuit is made up of triode BG3, BG4, electrochemical capacitor C8 and resistance R 7-R11, and power circuit is made up of coil L2, diode D9, capacitor C 7.The 3CT1 first anode, second plate have the lead that is connected with the fluorescent tube filament two ends respectively; delay circuit output connects the 3CT1 trigger electrode through R8; power circuit output cathode (D9 positive pole) end is connected with delay circuit input positive terminal, and protective circuit 4 is formed by one-way SCR 3CT2 and for 3CT2 provides the delay circuit and the power circuit of time-delay triggering.The delay circuit here is made up of resistance R 12, R3, voltage-stabiliser tube Dw and C9 electric capacity, and power supply is provided by the preheat circuit power supply, and the 3CT2 anode connects positive supply, and negative electrode connects preheat circuit R8 to 3CT1 trigger electrode.Present embodiment can use the fluorescent tube of various different capacities.

Its operation principle is as follows:

The 220V AC power is through rectifier bridge D1, D2, D5, D6 rectification, and filter capacitor is through D4 to C2 serial connection charge, and C1 is through D7, and C2 is through the output of D3 parallel discharge, and about the about 200V of output direct current, C0 then absorbs moment surge peak current.This filtering mode, charging capacitor is little, promptly the charging interval long, discharge capacity is big, thereby significantly reduces harmonic content.Output dc voltage is given inverter circuit work.When energized, inverter circuit C3 charges through R1, equals trigger tube D when C1 is charged to voltage _BDuring trigger voltage, D _BTrigger, electric current is through R1, D _BTo resonance triode BG2, make the BG2 conducting, the B1-2 induced current makes the BG1 conducting, and the B1-1 phase place is opposite with B1-2, BG2 is ended, and resonant tank is because effect of discharging and recharging and the oscillator coil effect of C5 make the BG2 conducting, repeat above-mentioned charge circuit, so repeatedly, resonance forms.Forming resonant tank moment, when L1 passes through electric current, L2 is induced current on L1, through the D9 rectification, C7 filtering, this moment, preheat circuit BG4 ended and the BG3 conducting, and electric current triggers bidirectional triode thyristor 3CT1 conducting from BG emitter, collector electrode through R8, lamp tube ends is equivalent to short circuit, and the resonant tank output current directly flows through through the two ends filament and makes filament pre-heating, lamp tube ends short circuit and do not have not starter of high pressure.After after a while, preheat circuit C8 charge to the certain hour filament pre-heating fully after, the BG4 conducting, and BG3 ends, controllable silicon 3CT1 trigger current is disconnected by BG3, controllable silicon is off-state, this moment, resonant tank was through dc power anode → tube filament → C6 charging → tube filament → C5 charging → L1 → B1, (during the BG2 conducting), during the BG1 conducting, BG1 emitter → B1L1 → C5 discharge → filament → C6 discharge → filament → BG1 collector electrode is in the resonant tank that ballast and fluorescent tube are formed, because C6 is significantly smaller than C5, so on C6, C6 is connected on lamp tube ends to loop pressure drop, makes lamp tube ends add a high pressure so basically, fluorescent tube is taken by force by height punctured and starter, then resonant tank directly flows through through fluorescent tube.The luminous work of fluorescent tube.

When supply voltage is too high; the resonant tank output current is along with increase; the L1 electric current of flowing through also increases; directly be coupled out induced voltage by L2 from L1; the voltage of the last output of L2 increases; at this moment; too high voltage inserts protective circuit 3CT2 trigger electrode via R13 to Dw; C9 delayed time after a bit of time, the 3CT2 triggering and conducting, and power supply makes the lamp tube ends short circuit through preheat circuit R8 triggering and conducting 3CT1; the output loop of inverter circuit becomes preheat mode like this; this operating state makes whole power loop very little, and resonant tank output is reduced, thus the protection ballast.When fluorescent tube is in abnormality; the resonant tank power supply enlarges markedly equally; the L1 electric current of flowing through is big; L2 voltage height; thereby make electric current puncture Dw and conducting 3CT2 through R13; 3CT2 is conducting 3CT1 again; make electric ballast be in preheat mode; the environmental protection of small-power output services ballast because after the disconnected conducting of 3,CT2 one, even the trigger electrode trigger current disappears; it still has the function of keeping; as long as the negative and positive voltage across poles is non-vanishing, it is in conducting state all the time, makes it to have defencive function completely.Direct voltage only is that whole resonant tank is the pay(useful) load of fluorescent tube basically about 200V behind the present embodiment rectifying and wave-filtering, and the L1 inductance value is very little, so entire circuit power factor (PF) height.Its preheat circuit can be exactly according to the requirement of fluorescent tube; with preheat curent and be controlled at suitable some warm-up time; thereby make the fluorescent tube long service life, and protective circuit has the protective capability to abnormity of power supply and abnormal condition of lamp tube, the useful life of electric ballast is also long naturally.

Embodiment 2

Shown in figure two; its current rectifying and wave filtering circuit is identical with the circuit structure of embodiment 1 with inverter circuit and protective circuit; different is that filament preheating circuit is by one-way SCR 3CT1; diode D9-D12 rectifier bridge replaces among the embodiment bidirectional triode thyristor 3CT1 in 1; its principle is that the interchange oscillation circuit electric current on the embodiment 1 bidirectional triode thyristor 3CT1 is controlled by an one-way SCR 3CT1 after rectifier bridge D9-D12 is rectified into direct current; other is identical with embodiment 1; the advantage of present embodiment is to provide a kind of small power electric sub-ballast; the trigger current that wherein triggers 3CT1 is minimum; preheating, the power consumption of protective circuit is extremely low and cost is low.

Embodiment 3

Shown in figure three; its current rectifying and wave filtering circuit is that the road is identical with the circuit structure of embodiment 1 with inverter circuit and protection; different is pre-thermoelectric by a bidirectional triode thyristor among two one-way SCR 3CT1,3CT2 and two diodes replacements of D10, the D11 embodiment 1; its principle is to cooperate two one-way SCRs to use the electric current of positive and negative two half-waves of the alternating current in the conducting resonant tank respectively by two diodes, and is very suitable when the resonance frequency of present embodiment in inverter circuit is high.

Embodiment 4

Shown in figure four, its current rectifying and wave filtering circuit, inverter circuit are identical with embodiment one, and different is that preheat circuit is only by a temperature sensing element R ⁰T constitutes; with capacitor C 9; the C10 parallel connection; there is the lead-out wire that connects fluorescent tube filament at its two ends; protective circuit is by one-way SCR 3CT1; and delay circuit; power circuit and triode BG3; resistance R 3; R4; R5; electrochemical capacitor C5 forms; here delay circuit is by resistance R 1; R2; voltage-stabiliser tube Dw; electrochemical capacitor C3 forms; power circuit is by inductance coil L1-2; diode; D8; electrochemical capacitor C4 forms; the 3CT1 anode connects the positive source of current rectifying and wave filtering circuit output; negative electrode is through R3; R4 connects the BG3 base stage; the BG3 collector electrode connects BG2 base stage in the inverter circuit, and the BG3 emitter connects the out-put supply negative pole of current rectifying and wave filtering circuit.Its operation principle is as follows: R in the preheat circuit ⁰Be low resistance during the t cold conditions, when inverter circuit resonance, resonant tank is because R ⁰T cold conditions resistance is little, makes the approximate conducting state of lamp tube ends and makes loop current directly flow through filament and preheating, at R ⁰T is after energising a period of time, and its resistance value rises rapidly and is high-impedance state, and lamp tube ends promptly adds high pressure and starter like this.The principle of protective circuit is basic identical with embodiment 1; different is the positive pole that one-way SCR 3CT1 anode directly connects current rectifying and wave filtering circuit output; after the controllable silicon conducting; electric current makes the BG3 saturation conduction through 3CT1 sun → 3CT1 the moon → R3, R4 step-down, because pressure drop is very low behind BG3 collector electrode and the emitter saturation conduction; the BG3 collector electrode connects inversion circuit BG2 base stage; the BG3 emitter links to each other with BG2, is about to inverter circuit BG2 base stage and emitter short circuit like this, and the resonance of inverter circuit stops.Thereby protected ballast.The anti-interference of present embodiment is extremely strong, is applicable to large-power occasions.

Claims

1, a kind of high power factor electric ballast with preheating protection function, it is characterized in that by current rectifying and wave filtering circuit 1, inverter circuit 2, filament preheating circuit 3 and protective circuit 4 are formed, the input of the rectifier bridge in the current rectifying and wave filtering circuit 1 connects the 220V AC power conductors, the output of current rectifying and wave filtering circuit 1 is connected with inverter circuit 2 power inputs, output in the inverter circuit 2 has the lead that connects the lamp tube ends filament, the output of filament preheating circuit 3 has two leads in addition that connect tube filament, filter circuit in the current rectifying and wave filtering circuit 1 is by diode D3, D4, D7 and capacitor C 0, electrochemical capacitor C1, C2 constitutes, the positive pole of rectifier bridge is connected with D3 negative pole and C1 positive pole, the rectifier bridge negative pole is connected with D7 positive pole and C2 negative pole, the D3 negative pole is connected with C2 positive pole and D4 negative pole, D4 is anodal to be connected with C1 negative pole and D7 negative pole, C0 is connected in parallel on the both positive and negative polarity of rectifier bridge output, filament preheating circuit 3 is formed by controllable silicon 3CT1 and for 3CT1 provides the delay circuit and the power circuit that trigger time delayed turn-off, the 3CT1 first anode, second plate is drawn the lead that connects filament respectively, the output of delay circuit connects the trigger electrode of 3CT1, protective circuit 4 is formed by one-way SCR 3CT2 and for 3CT2 provides the delay trigger circuit and the power circuit of time-delay trigger current, the 3CT2 negative electrode connects the 3CT1 control utmost point in the preheat circuit 3, anode contact energy source;

2, according to the described electric ballast of claim 1, it is characterized in that filament preheating circuit 3 is made up of rectifier bridge D9-D12 and one-way SCR 3CT1, the input of rectifier bridge D9-D12 has the lead-out wire that connects the fluorescent tube lamp line, the positive pole of output connects the 3CT1 anode, and the negative pole of output connects the negative pole in the preheat circuit 3;

3, according to the described electric ballast of claim 1, it is characterized in that filament preheating circuit 3 is made up of 3CT1,3CT2 one-way SCR and diode D10, D11, the anode of 3CT1 and 3CT2 has the lead that connects tube filament respectively, the negative pole of D10 is connected with the 3CT1 anode, the D11 negative pole is connected with the 3CT2 anode, and the positive pole of D10, D11 all is connected with negative pole in the preheat circuit 3;

4,, it is characterized in that filament preheating circuit 3 is by thermo-sensitive resistor R according to the described electric ballast of claim 1 ⁰T constitutes, capacitor C 9, C10 series connection back and R ⁰The t parallel connection, R ⁰The t two ends connect the tube filament lead; protective circuit 4 by one-way SCR 3CT1 and for 3CT1 provide the time-delay trigger current delay circuit; power circuit and resistance R 3; R4; R5; electrochemical capacitor C5; triode BG3 forms; its delay circuit is by resistance R 1; R2; voltage-stabiliser tube DW; electrochemical capacitor C3 constitutes; its power circuit is by inductance coil L1-2; diode D8; electrochemical capacitor C4 constitutes; the 3CT1 anode connects direct current output cathode in the current rectifying and wave filtering circuit 1; negative electrode is through R3; R4; R5 is connected with the BG3 base stage; the BG3 collector electrode connects the BG2 base stage in the inverter circuit 2, and emitter connects direct current output negative pole in the current rectifying and wave filtering circuit 1.