CN2120387U - Cathodeless long life daylight lamp tube - Google Patents

Abstract

The utility model relates to a long life daylight lamp tube without cathode, which is used in daily life and work. The utility model needs no preheating or the vulnerable cathode (filament) which emits electrons; the electrode which replaces the cathode is made of metallic filaments to lead in the high-frequency impulse voltage of a ballast, so as to make the daylight lamp arc discharge to start the lamp tube. The wire electrodes of the lamp tube are serrated or cochleate; one or two contact conductors are arranged on each end of the lamp tube; the joints of electrodes and the contact conductors are sealed in sealing glass at the end of the lamp tube. The utility model has the advantages of long service life, easy producing, low cost, safe and reliable operation and strong practicability, and is electricity-saving.

Description

Cathodeless long life daylight lamp tube

The utility model belongs to the fluorescent tube of daily life work with fluorescent lamp.

The fluorescent tube that uses belongs to pre-heated fluorescent tube at present, and its life-span depends primarily on the length in negative electrode (filament) life-span of emitting electrons, and before startup, the temperature of negative electrode should reach between 850 ℃-900 ℃, otherwise to the lamp tube service life influence greatly.Because when negative electrode is not heated to said temperature, just can not launch abundant electronics, if the contact of starter just disconnects at this moment, the high voltage pulse that two interpolars produce is easy to make the oxide on the negative electrode to splash, and causes the lamp tube end blackout.Once fail to light fluorescent tube if start, then the starter contact is closed once more, and said process repeats again, till lamp tube starting.The starter contact repeatedly disconnects and is closed, circuit is produced impact to involve the heavy current vibration, makes the aging or fracture of negative electrode impaired (" focus " that particularly exist on the negative electrode), electronics powder splash to come off fluorescent tube blackout, life-span are subtracted greatly.In addition, negative electrode is very thin, and vibration resistance is not strong, is subject to mechanical shock etc. and ruptures.

In whole numbers of starts, the relative percentage value that negative electrode is not heated to the instantaneous starting that promptly starts more than 850 ℃ is bigger, and then the life-span of negative electrode is short more.When instantaneous starting percentage 40%, the lost of life 1/5; When all being instantaneous starting, its life-span will shorten 2/3.The general one-shot of fluorescent lamp is lighted seldom, and the situation that 2-4 time even more times startup are lighted occupies the majority, the main cause that lamp tube service life that Here it is is short.

The negative electrode of fluorescent tube can reach 850 ℃ later on again row start, this warm-up time with negative electrode is relevant, the latter is relevant with the length of starter time of closing contact again.Starter commonly used is a glow starter, and closing time was designed to about 2 seconds, but owing to be subjected to the influence of voltage, temperature etc., this time is very inaccurate: when voltage was higher than 220 volts, the starter closing time was extremely short, caused instantaneous starting; When voltage was lower than 220 volts, starter once closure was difficult to light fluorescent tube, caused repeatedly instantaneous starting just can light fluorescent tube, thereby it is more serious just to light the anticathode damage of fluorescent tube than one-shot; When ambient temperature and brownout, starter is difficult to closed, and even not closed, lamp just can not be lighted.

In recent years, people have developed electric ballast, and it has the light a lamp function of pipe of instantaneous disposable start-up point, and having overcome inductance type iron core ballast and starter preferably needs repeatedly to start the shortcoming that just can light fluorescent tube.Electric ballast still adopts four line connections, is about to tube cathode and is connected in series with the electric ballast output circuit, to adapt to the mode of connection of pre-heated fluorescent tube.This is not only unnecessary, and there is the harm of surge voltage and electric current equally in target, makes negative electrode early ageing blackout or fracture, causes lamp tube service life to shorten.If electric ballast operating frequency design De Taigao, then the life-span of fluorescent tube only slightly prolongs than the life-span of using the Inductive ballast ballast, even long not as good as the lamp tube service life of using Inductive ballast.But because electric ballast has energy-conservation; the power factor (PF) height; no stroboscopic; noiselessness; advantages such as low-temp low-pressure startup; add that people are to the weak point of electric ballast such as self be subject to surge voltage and the updating (as Chinese utility application---electric ballast of rush of current infringement etc.; application number is 91214405.X-6; it has the anti overvoltage function; and improvement output circuit structure; short circuit filament starter; with protection fluorescent tube and inherently safe); electric ballast has very big potential market; society and economic benefit and progressively replace the development trend of Inductive ballast, this improves operation principle and method of work to adapt to electric ballast with regard to necessary to pre-heated fluorescent tube.

From as can be known above-mentioned,, mainly be to the extent of damage decision of the negative electrode of fluorescent tube emitting electrons to the life-span extent of injury of pre-heated fluorescent tube no matter be Inductive ballast or electric ballast.Because it is the arc discharge burning that fluorescent tube is lighted principle, so only need suitably to increase the starting resistor of lamp tube ends electrode, just can replace the effect of the negative electrode of emitting electrons.

The purpose of this utility model is to design a kind of no negative electrode at the deficiency of prior art, need not preheating the fluorescent tube of (electrode that only needs to import supply voltage), with the supporting use of electric ballast, with prolonging lamp tube service life at double, simplify lamp tube structure and manufacture craft, reduce and produce and use cost.

This fluorescent tube also can be used with inductance type ballast, and effect is the same, but must redesign or improve traditional iron core formula Inductive ballast, makes it to produce enough starting voltages, and starts the back at fluorescent tube and play normal ballast effect.

The utility model is on the architecture basics of present pre-heated fluorescent tube, the negative electrode that saves emitting electrons is a filament, the direct connection of the electrode of anchored filament can be formed new electrode, also can on demand electrode be made various suitable shapes, all the other manufacture crafts requirements and material specification etc. are identical with the pre-heated fluorescent tube of making, need not change, but the total length that is exposed to the electrode in the fluorescent tube should there be 3～10 centimetres, guarantee that discharge normally carries out.

It is cold start-up that the utility model changes warm start, and electrode need not generate heat and emitting electrons, and the electrode metal filament diameter can be done greatlyyer than filament diameter, thus be difficult for impaired, prolonging lamp tube service life; Economize on electricity; Save noble metal; Reducing fluorescent tube makes and use cost.

Below in conjunction with accompanying drawing utility model is described further.

Fig. 1 is for the utility model four is drawn stitch formula schematic diagram;

Fig. 2 is for the utility model two is drawn the stitch schematic diagram.

With reference to Fig. 1, the utility model does not have the negative electrode of heating and electron emission, but directly make electrode with the wire short circuit of making the preheating fluorescent tube anchored filament, ballast voltage is imported fluorescent tube, the high-frequency pulse voltage that utilizes ballast to produce starts fluorescent tube, and the fluorescent tube arc discharge is lighted. 4 centimetres of electrode length overalls are made sawtooth pattern, and dotted portion is leading foot and electrode contact glass-dead seal part, and drawing stitch is four, to adapt to the requirement of four line connections.

With reference to Fig. 2, operation principle of the present utility model is identical with Fig. 1's. 8 centimetres of electrode length overalls make screw type, and dotted portion is leading foot and electrode contact glass-dead seal part, and drawing stitch is two, to adapt to the requirement of two line connections.

Embodiment of the present utility model is as follows:

1, as Fig. 1, with sealing the corresponding to wire of glass coefficient of thermal expansion and contraction, diameter and length (can directly use filament Support Level and lead-out wire that pre-heated fluorescent tube uses) with fluorescent tube, directly short circuit forms electrode in lamp tube ends, draws two leg respectively, totally 4 leading foots.All the other manufacture crafts, material requirements are with pre-heated fluorescent tube.

2, as Fig. 2, form electrode according to embodiment 1 short circuit wire, each only draws a leg two ends, totally two leading foots.All the other manufacture crafts, material requirements are with pre-heated fluorescent tube.

Claims (3)

1, a kind of no negative electrode long-life fluorescent tube, constitute by fluorescent tube, electrode and contact conductor, it is characterized in that electrode is a wire, connects the lead-in wire of lamp tube ends respectively, the joint of electrode and lead-in wire is encapsulated in sealing in the glass of lamp tube end, and drawing the outer lead-in wire of the every end of fluorescent tube is one or two.

2, fluorescent tube according to claim 1, the electrode that it is characterized in that being exposed in the fluorescent tube is long for 3-10 centimetre.

3, fluorescent tube according to claim 1, what it is characterized in that wire electrode is shaped as dentation or helical form etc.

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