CN2148455Y - Fluorescent lamp starting preheater matching with electronic ballast - Google Patents

Abstract

The utility model relates to a fluorescent lamp starting preheater having at least one positive temperature coefficient thermal resistor. Connected between two filaments, the preheater is directly or indirectly connected in parallel with the primary oscillation capacitor of the electronic ballast. Matched with the preheater, the preheating current of the filament of the fluorescent lamp is high, the starting voltage of the fluorescent lamp is low, and the preheater withdraws from operation in high-impedance state after the fluorescent lamp is started, protecting the filament and extending the service life of the fluorescent lamp remarkably. The utility model has the advantages of simple structure, low cost and convenient installation. The preheater can be designed to patch with the lamp in a container alone. The utility model is compatible with the lamp failure protection technique of the electronic ballast or the not start-up protection technique and can be collocated with each other.

Description

Fluorescent lamp starting preheater matching with electronic ballast

The utility model is a kind of fluorescent lamp starting preheater of joining single, multi-lamp electric ballast (hereinafter to be referred as electric ballast).

Compare with inductance type ballast, electric ballast has advantages such as efficient electricity-saving, no buzzer, no stroboscopic sense and energy low voltage starting.A machine electronic ballast for multiple lamps particularly, ratio of performance to price height has a extensive future.But common electric ballast mostly is quick startup formula, the then preheating cathode types that belong to of commercially available fluorescent lamp more.Because electric ballast without preheating function, fluorescent lamp is promptly punctured under too high terminal voltage by force without filament pre-heating, causes the electronic emitting material on filament surface to consume above set limit down to sputter filament premature aging, the very fast blackout in lamp two ends, the lost of life.

Task of the present utility model is, for the fluorescent lamp of the common electric ballast of adapted provides a kind of lamp to start preheater.When fluorescent lamp starting, at first through the time-delay of one section preheating filament, and then with not too high starting voltage lamp to be lighted, the electronic emitting material on protection filament and surface thereof prolongs life-span of lamp.

Of the present utility model being characterised in that: the fluorescent lamp starting preheater has a semistor at least, but this thermistor series and parallel impedance component also can directly or behind the series and parallel impedance component be connected with the outlet side of a rectification link.The terminal that produces behind the two ends of this thermistor or the series and parallel impedance component or the input of rectification link are two terminals of preheater.(main oscillations electric capacity can have several to two filaments that the two ends of preheater are connected lamp near main oscillations electric capacity in the LCR circuit of electric ballast, down together) on two lamp bases of end, perhaps be connected and comprise the two ends of main oscillations electric capacity at least between two lamp bases at interior any circuit section, preheater can be an one with Design of Digital Ballast both, also can be installed in the container whole or in part, two terminal is drawn, connect with fluorescent lamp and electric ballast.

Below, concrete feature of the present utility model and embodiment are described in conjunction with the accompanying drawings.

In the accompanying drawing 1 dot-dash wire frame A is fluorescent lamp starting preheater of the present utility model, and surplus is fluorescent lamp and electric ballast and the closely-related part of preheater A.Two ends D, the D of preheater A is connected two filament R of fluorescent lamp ₁, R ₂Two lamp base E of close electric ballast main oscillations capacitor C (C can have several) end ₁, E ₂On, perhaps be connected E ₁With E ₂Between comprise the two ends of C at least at interior any circuit section.Preheater A has a semistor R _{T ℃}R _{T ℃}Both can be the slow change type semistor, can be again the switching mode semistor, also can be the semistor that Curie point or switch temperature are arranged, and can also be the semistor with critical temperature.R _{T ℃}Can the series and parallel impedance component, also can directly or behind the series and parallel impedance component be connected with the outlet side of a rectification link.R _{T ℃}Two ends or R _{T ℃}The terminal that produces behind series and parallel resistance, the anti-element or the input of rectification link are two terminal D, the D of preheating A.Preheater A in the accompanying drawing 1 is by R _{T ℃}With an adjustment resistance R _aBe in series, and produce two terminal D, D.Rationally select R for use _aResistance, the filament pre-heating electric current and the warm-up time that can obtain to suit.R _aCan economize simultaneously with its shorted on both ends.Preheater A can be an one with Design of Digital Ballast both, also can be installed in whole or in part in the container, and two terminal D, D are drawn, and connected with electric ballast and fluorescent lamp.

Now with R _{T ℃}For semiconductive ceramic material semistor PTC with Curie point or switch temperature is an example, analyzes the adapted electric ballast and add the operation situation in the fluorescent lamp starting stage of preheater A.

T---the R curve that accompanying drawing 2 changes corresponding to himself temperature T for the resistance R of PTC.Accompanying drawing 3 is adapted electric ballast and the terminal voltage U that adds the fluorescent lamp starting stage lamp of preheater A ₁Along with the passing of time t changes corresponding to PTC resistance R and the waveform that changes.At the beginning of the electric ballast energising, oscillating current is through R ₁, R ₂Flow to C and A, PTC begins to heat up, and rises to Curie point or switch temperature T at T _bBefore, R slightly descends, but shows as a constant R that numerical value is less substantially ₂₅Because PTC is in parallel with C, be equivalent to resistance value ratio R this moment ₂₅A little bit smaller slightly resistance and appearance value are connected in the LCR oscillating circuit of electric ballast then than the big a lot of capacitances in series of C, so LCR circuit oscillation frequency f is lower, quality factor q is less, so dividing potential drop peak value and then U on the C ₁Amplitude lower and more stable, lamp is not lighted, oscillating current is to R ₁, R ₂Heating.Along with the passing of t and the accumulation of PTC heat, T meets and exceeds T _b, R skyrockets, and the equivalent resistance and the equivalent capacity of PTC and C parallel circuits are more and more littler, and f is more and more higher, and the Q value is increasing, dividing potential drop on the C and then U ₁Amplitude also more and more higher, preheat curent is also increasing, preheating is quickened.Through width is t _D1Preheating time-delay, T rises to quite high T _POr maximum of T _N, U this moment ₁Exist a higher peak value that lamp is lighted.After lamp is lighted, U ₁Go down after a rise to light working voltage.In lamp normal work period after this, still have the small electric current PTC that flows through.Be subjected to the influence of factors such as voltage, ambient temperature, dissipation factor, PTC reaches a kind of dynamic equilibrium between electric current that flows through it and T, R or be stabilized in its maximum, perhaps be stabilized in and be lower than on the peaked higher resistance value, be to maintain high-impedance state in a word, wasted work is very little, is similar to open circuit, PTC is equivalent to out of service, no longer lamp work is produced obviously influence.

Above-mentioned analysis is applicable to R _{T ℃}For the switching mode semistor with have a situation of the semistor of critical temperature.R _{T ℃}Situation during for the slow change type semistor is slightly different, difference is, the slow change type semistor does not have tangible Curie point or switch temperature section and the T-R slope of curve less, should select the big or high person of temperature coefficient of normal temperature resistance when therefore using as much as possible.

Accompanying drawing 4 does not have the lamp terminal voltage U in fluorescent lamp cold start-up stage of the electric ballast of preheat function for adapted ₂T changes and the waveform of variation in time.Can find out U in the accompanying drawing 3 significantly ₁Light t constantly at lamp _D1Peak value, be significantly less than U in the accompanying drawing 4 ₂Light t constantly at lamp _D2Peak value.As seen, preheater A of the present utility model has significant protective effect to the electronic emitting material on the Filament of fluorescent lamp of adapted electric ballast and surface thereof, life-span that can the significant prolongation lamp.

Claims (3)

1, a kind of fluorescent lamp starting preheater A that joins the single, multi-lamp electric ballast, it is characterized in that: preheater A has a semistor R at least _{T ℃}, R _{T ℃}Can series and parallel resistance, anti-element, also can directly or series and parallel hinders, link to each other R with the outlet side of rectification link behind the anti-element _{T ℃}Two ends or R _{T ℃}The terminal that produces behind series and parallel resistance, the anti-element or the input of rectification link are two terminal D, the D of preheater A; D, D are connected two filament R of fluorescent lamp ₁, R ₂Two lamp base E of main oscillations capacitor C (C can have several) end in the LCR circuit of the single, multi-lamp electric ballast of close its adapted ₁, E ₂On, perhaps be connected E ₁, E ₂Between comprise the two ends of C at least at interior any circuit section.

2, according to the fluorescent lamp starting preheater of claim 1, it is characterized in that: described R _{T ℃}Both can be the slow change type semistor, can be again the switching mode semistor, also can be the semistor that Curie point or switch temperature are arranged, and can also be the semistor that critical temperature is arranged.

3, according to the fluorescent lamp starting preheater A of claim 1, it is characterized in that: described preheater A can be an one with the single, multi-lamp Design of Digital Ballast both, also can be installed in whole or in part in the container, two terminal D, D are drawn, with two filament R of fluorescent lamp ₁, R ₂Two lamp base E of main oscillations capacitor C (C can have several) end in the LCR circuit of the single, multi-lamp electric ballast of close its adapted ₁, E ₂Connect, perhaps with E ₁With E ₂Between the C that comprises at least connect at the two ends of interior any circuit section.

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