CN2269691Y - Electronic ballast - Google Patents

Abstract

The utility model relates to an electronic ballast, which is composed of a rectifying and filtering circuit, a high-frequency oscillating circuit, etc. An NTC thermistor is respectively connected in parallel to leading wires of filaments of both ends of an accessed fluorescent lamp tube or a compact fluorescent lamp tube. The electronic ballast of the utility model has low manufacture cost and simple circuits; the electronic ballast not only can retain all advantages in the use of the ballast and reduce energy loss, but also can prolong the actual service life of fluorescent lamps and enhance the light effect of lamp tubes.

Description

Electric ballast

A kind of electric ballast, specifically a kind of fluorescent tube electric ballast in useful life that prolongs relates to the improvement of circuit of electronic ballast.

Through the several years research and development, the quality of electric ballast self and life-span are improved widely and are progressively accepted by the user.Generally the situation of reflection is that fluorescent tube is shorter than Inductive ballast the useful life in being used with electric ballast now, and it is electric ballast and working method different cause of Inductive ballast to fluorescent lamp that the someone proposes this.Because Inductive ballast is to adopt the starter mode that Filament of fluorescent lamp is carried out after the preheating just starter, the shortcoming of the serious sputter of electronics powder when not producing cold start-up, heater chain cut-offs behind the fluorescent tube starter, have only lamp current and do not have heater current, thereby the filament evaporation is aging relative few with the electronics powder, go wrong so long as not starter, the useful life of fluorescent lamp is longer relatively; Electric ballast then is to adopt the mode of the higher-order of oscillation that light pipe is lighted, and under the high-frequency and high-voltage state, even filament does not have preheating, fluorescent tube equally can build-up of luminance.Just because of this, sputter is very serious to this cold starter phenomenon to the electronics powder, thereby causes short phenomenon of fluorescent tube life-span to take place.For this reason, a lot of people take to have increased filament preheating circuit on electric ballast.When but fluorescent tube uses electric ballast to make current limliting, its operating frequency is elevated to 20KHZ～50KHZ, near the characteristic of electrode is changed, make negative electrode keep certain temperature again in order to reduce ion bombardment, after fluorescent tube is lighted, need the certain heating current of maintenance, to guarantee enough electronics emissions.Like this, the time enough electric currents are arranged owing to take starting into account, fluorescent tube is lighted after still during operate as normal, filament will keep excessive electric current; Add emission current and can pass through filament simultaneously, it is seriously overheated that filament still causes when light pipe is worked, and makes the oxidation material accelerated evaporation, and serious meeting causes the tungsten evaporation, this just produces early stage blackout and early stage fracture of wire phenomenon, and this all is to have constituted fluorescent tube short main cause in useful life.Thereby, guarantee that electric ballast not only economizes on electricity but also save money the actual life when improving fluorescent tube use electric ballast, be the key of promoting Green Lighting Project.

The purpose of this utility model provides a kind of simple in structurely, and cost is lower, has both possessed the every advantage of electric ballast, can prolong fluorescent tube useful life again effectively, reduces the electric ballast of electric ballast energy consumption.

The utility model is to implement like this, by current rectifying and wave filtering circuit, and in the electric ballast that high-frequency oscillating circuits is formed, on the lead-in wire of fluorescent lamp (or compact fluorescent lamp) lamp tube ends filament 1, filament 2, each negative tempperature coefficient thermistor NTC in parallel ₁, NTC ₂

Fig. 1 is circuit of electronic ballast figure described in the utility model;

Fig. 2 be described in the utility model on negative tempperature coefficient thermistor the circuit of electronic ballast figure of diode in parallel.

Below in conjunction with accompanying drawing in detail enforcement of the present utility model and principle are described in detail.

As shown in Figure 1, the 220V AC power is through fuse R _x, connect to by diode D ₁-D ₄, capacitor C ₁The current rectifying and wave filtering circuit of being formed.Behind power connection, resistance R ₁To capacitor C ₂C is worked as in charging ₂On voltage equal trigger tube D ₆Starting resistor after, D ₆Trigger, electric current is through R ₁, D ₆, R ₃To vibration T ₂Base stage, make T ₂The pipe conducting; At this moment inductor L ₁-1 induced current makes oscillating tube T ₁Conducting, and L ₁-2 phase places and L ₁-1 is opposite, T ₂Pipe ends simultaneously, and resonant tank is then because C ₄Discharge and recharge and oscillator coil L ₁Effect, make T again ₂The pipe conducting, entire circuit forms vibration.After producing the inversion vibration, owing to be parallel to oscillating capacitance C ₄The thermistor PTC at two ends (can also adopt other filament pre-heating mode) is a low resistance during cold conditions, make lamp tube ends be similar to conducting, at this moment, because NTC thermistor resistance when cold conditions is higher, circuital current carries out preheating by filament 1, thermistor PTC, 2 pairs of filaments of filament; After thermistor PTC energising a period of time, its resistance is high-impedance state rapidly with the rising of resistance temperature, equals to add high pressure and begins starter in lamp tube ends.Because at the tube starting leading portion, circuit has carried out preheating to filament, the electronics powder sputtering phenomenon that has occurred when having avoided owing to cold start-up; Behind the filament pre-heating starter, thermistor NTC ₁, NTC ₂Its resistance also is low resistive state rapidly with the rising of resistance temperature, fully acting on, the electric current that flows through filament is reduced relatively, and main electric current is a lamp current with filament 1, filament 2 backs in parallel, in fluorescent tube, circulate, thereby avoided having on the filament big electric current that the phenomenon of oxidation material evaporation is produced.Owing to adopted at filament 1, filament 2 thermistor NTC in parallel ₁, NTC ₂Structure, both guaranteed that starting had enough heater currents at the beginning, can behind the fluorescent tube starter, be low resistive state by filament again, thereby reduced the power consumption of electric ballast on filament, reduced the heater current of fluorescent tube, made the certain heating current of its maintenance, to guarantee is enough thermionic emission, the filament evaporation is reduced, and electronics powder aging period prolongs, the light efficiency and the useful life of having improved fluorescent tube effectively.

As shown in Figure 2, further reduce, alleviate the energy loss of filament after the light pipe conducting in order to make heater current connect the back at fluorescent tube, can be on the two ends of fluorescent tube or compact fluorescent lamp tube filament 1,2 thermistor NTC ₁, NTC ₂Two ends, respectively in parallelly again insert a diode D ₉, D ₁₀, like this, the electric current on the filament is further shunted from diode when the diode forward conducting, thereby improves the light efficiency of light pipe.

Adopted electric ballast described in the utility model, because cost of manufacture is low, processing technology is simple, all advantages that both can keep electric ballast, reduce the filament energy consumption of electric ballast to fluorescent tube, can improve the light efficiency of fluorescent tube again, the life-span when guaranteeing to prolong effectively fluorescent tube and electric ballast and being used.

Claims (2)

1, a kind of electric ballast, by current rectifying and wave filtering circuit, compositions such as high-frequency oscillating circuits is characterized in that on the lead-in wire of fluorescent tube (or compact fluorescent lamp tube) two ends filament 1, filament 2, negative tempperature coefficient thermistor NTC of access in parallel respectively ₁, NTC ₂

2, electric ballast according to claim 1 is characterized in that at said negative tempperature coefficient thermistor NTC ₁, NTC ₂On can distinguish diode D in parallel ₉, D ₁₀

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