Fluorescent lighting connection. Connect the burnt fluorescent lamp
We offer two options for connecting fluorescent lamps, without the use of a choke.
All fluorescent lamps operating on AC power (except for lamps with high-frequency converters) emit a pulsating (with a frequency of 100 pulsations per second) luminous flux. This acts tiringly on people's eyesight, distorts the perception of rotating knots in the mechanisms.
The proposed lamp is assembled according to the well-known power supply scheme of a fluorescent lamp with a rectified current, characterized by the introduction of a K50-7 high-capacity capacitor for smoothing pulsations into it.
When you press a common key (see diagram 1), the pushbutton switch 5В1 is activated, which connects the luminaire to the electrical network, and the 5В2 button, which closes the glow circuit of the LD40 fluorescent lamp with its contacts.When the keys are released, the 5V1 switch remains on, and the SB2 button opens its contacts, and the resulting EMF self-induction lamp lights up. When the key is pressed a second time, the SB1 switch opens its contacts and the lamp goes out.
The description of the switching device is not given because of its simplicity. For even wear of the filament of the lamp, the polarity of its inclusion should be changed after about 6000 hours of operation. The luminous flux emitted by the lamp has practically no pulsations.
Diagram 1. Connections of a fluorescent filament lamp (option 1.)
Even lamps with one burnt thread can be used in this lamp. To do this, its conclusions are closed on the base with a spring of thin steel string, and the lamp is inserted into the lamp so that the rectified voltage is applied to the closed legs (upper thread in the diagram).
Instead of a capacitor of brand KSO-12 per 10,000 pf, 1000 V, a capacitor from a failed starter for LDS can be used.
The main reason for the failure of fluorescent lamps is the same as that of incandescent lamps - a blown filament. For a standard luminaire, a fluorescent lamp with this kind of malfunction is, of course, unsuitable, and must be discarded.Meanwhile, according to other parameters, the resource of a lamp with a burnt filament often remains far from being worked out.
One of the ways to "resuscitate" fluorescent lamps is the use of cold (instantaneous) ignition. To do this, at least one of the cathodes must be
get up with emission activity (see the scheme that implements this method).
The device is a diode-capacitor multiplier with a multiplicity of 4 (see diagram 2). The load is a chain of series-connected gas-discharge lamps and incandescent lamps. Their power is the same (40 W), the nominal supply voltage is also close in magnitude (respectively 103 and 127 V). Initially, when an alternating voltage of 220 V is applied, the device operates as a multiplier. As a result, a high voltage is applied to the lamp, which provides “cold” ignition.
Scheme 2. Another option for connecting a fluorescent fluorescent lamp.
After the occurrence of a steady glow discharge, the device switches to the full-wave rectifier mode loaded with active resistance. The effective voltage at the output of the bridge circuit is almost equal to the network one.It is distributed between the lamps E1.1 and E1.2. Incandescent lamp performs the function of a current-limiting resistor (ballast) and at the same time it is used as an illumination, which increases the efficiency of the installation.
Note that the fluorescent lamp is actually a kind of powerful Zener diode, so that changes in the magnitude of the supply voltage affect mainly the glow (brightness) of the incandescent lamp. Therefore, when the mains voltage is characterized by increased instability, the E1_2 lamp should be taken with a power of 100 W for a voltage of 220 V.
The combined use of two different types of light sources, complementary to each other, leads to an improvement in lighting characteristics: the pulsations of the light flux decrease, the spectral composition of the radiation is closer to the natural one.
The device does not exclude the possibility of using as a ballast and a typical choke. It is connected in series at the input of a diode bridge, for example, in an open circuit instead of a fuse. When replacing the D226 diodes with more powerful ones - the KD202 series or the KD205 and KTS402 (KTS405) blocks, the multiplier allows you to power the fluorescent lamps with a power of 65 and 80 W.
Properly assembled device does not require adjustment.In the case of fuzzy ignition of a glow discharge, or in the absence of one at all at the nominal mains voltage, the polarity of the fluorescent lamp should be changed. Previously it is necessary to make a selection of burnt out lamps to identify the possibility of working in this lamp.
The article will consider the repair of fluorescent lamps. Despite the fact that this type of llamas serves for a long time, they still fail. To understand the possible causes of failure, you need to understand the principle of their action.
A fluorescent lamp is a flask filled with an inert gas with the addition of mercury vapor. Along the edges of the lamp into the flask are soldered to a pair of electrodes, which are connected to the spiral of tungsten. Fluorescent lamp spirals are similar to those used in incandescent lamps. The difference is that the surface of tungsten is covered with a film of alkali metals. This is due to the purpose of the spirals: their task is not to shine, but to release free electrodes into the surrounding space. Also, the cathodes of the electron tubes work during heating.
The lamp is divided into two stages: start and glow.When starting, the starter connects the spirals of electrodes located at the edges of the lamp to the mains supply in series with the choke. The filaments are heated, free electrons are released from them into the surrounding space.
Then the starter opens its contacts and a high voltage pulse is generated between the electrodes at the edges of the lamp due to the emf of self-induction. Electrons come into motion. The current through the gas gap of the lamp during operation is limited by the inductive resistance of the choke.
On their way, electrons meet inert gas molecules and ionize them. As a result, molecules lose free electrons and become positive charges - ions. So the number of carriers of electric current is maintained in the lamp.
When meeting with mercury atoms, the electrons do not ionize them, but give energy to the electrons that make up its composition. Electrons are excited, moving to a higher orbit. But this state is unstable and lasts a short time. Returning to their place, the electrons give off energy in the form of ultraviolet radiation into the surrounding space.
The bulb of the lamp from the inside is coated with phosphor - a substance that can glow under ultraviolet light.So the energy of ultraviolet radiation is converted into visible light, the hue of which depends on the type of phosphor used.
Repair of fluorescent lamps: major faults
It is possible to break the tightness of the lamp only by breaking it. Gas leakage from its internal cavity is impossible. The reasons why the lamps fail are the following:
- blown filament;
- violation of filament coverage;
- depletion of phosphor.
At violation of the properties of the phosphor coating of the lamp, the color of its glow changes or its brightness decreases. It is impossible to restore such a lamp.
When shedding or fading the coating of the electrodes at startup, fewer free electrons are released. The lamp does not light up, and it can be seen that the heating of the filaments occurs: at the edges of the lamp there is a reddish glow that occurs when the starter contacts close.
The most common cause of failure of the lamp - blown filaments . It occurs for the same reasons as in incandescent bulbs. Additionally, this is facilitated by the shedding or evaporation of the layer covering the tungsten. The metal from the exposed areas evaporates, the thickness of the filament decreases. At the next start, the thread breaks.If one of the two electrodes has blown, the lamp will not start up anymore, since the start circuit is interrupted through the starter.
Scheme for starting a faulty fluorescent lamp
A lamp with broken filaments can be made to work even more. To do this, the launch scheme is fundamentally changed: the starter and the throttle will no longer help.
Electronic components in the circuit for different lamp powers are selected from the table
|Rated power, W||Capacitors C1, C2||Capacitors C3, C4||D1-D4 diodes|
|30||4 uF x 350 V||3300 pF||D226 B|
|40||10 uF x 350 V||6800 pF||D226 B|
|80||20 uF x 350 V||6800 pF||D 205|
CapacitorsC1 andC2 - paper, metal or similar,C3 andC4 - mica, but they must withstand a working voltage not lower than 350 V, like the previous ones. The rectifier diodes in the table are outdated, instead of them you can use modern models that can withstand direct current of at least 0.5 A and reverse voltage - 400 - 600 V.
The circuit is a double-wave rectifier with voltage doubling. Consider the principle of its work, dividing it into three stages.
The process is repeated with the frequency of the mains. CapacitorsC3 andC4 designed to protect against interference.
Read more about capacitors read articles: "" and "".
It is easy to see that the lamp is operating at a constant current (the direction is indicated in the last figure by the red arrow). Therefore, mercury vapor is gradually shifted towards one of the electrodes, which is why the lamp does not glow uniformly. To compensate for this deficiency, the electrodes of the lamp are reversed, turning it over in the luminaire. The second drawback is the frequency of the pulsation of the light of the lamp is doubled.
Therefore, the method of launching burnt fluorescent lamps is recommended for cognitive purposes, or for use in rooms where the requirements for the quality of lighting are low and the light in them is turned on rarely and for a short time.
In the autumn, he put the order in the garage and found three old burnt fluorescent lamps. Marking - FL18S / D (fig.1 ), length about 60 cm, diameter 26 mm. In one, the luminophore began to crumble inside the tube, and the two apparently still intact. I decided to remember the youth and make a lamp for the garage workbench, lighting the lamp from the rectifier-doubler mains voltage of 220 V.
I met this scheme in the magazines "Young Technician" and "Fish Breeding and Fisheries" in the section on aquariums - earlier it was much easier to find a burned-out lamp and solder four D7Z diodes with two MBM 0.1 μF capacitorsfig.2 ) than to search for a choke, a starter and a lamp with whole threads (there is a similar circuit and). An ordinary incandescent lamp was used as a ballast that takes on excess voltage after ignition of a fluorescent lamp. The brightness of the fluorescent lamp depends on the resistance of its thread.
First, of course, you need to check the lamps for the possibility of working in such a scheme. A bridge of 1N4006 diodes was soldered by a mounted installation, MPR 0.1 μF 400 V film capacitors were soldered to it, and the rest of the commutation was divorced. Incandescent lamp set power of 40 watts. The first tube lit up without any problems (fig.3 ), the second outwardly whole did not want to work, but the one that was rejected due to the shedding of the phosphor also lit up, but only after replacing the 40-watt incandescent lamp with a 60-watt lamp.
So, well, now it's up to the hull. The luminaire planned to be installed in the garage above the workbench, so the body needs to be strong and preferably so that it covers the lamps from above and in front from an accidental blow - a garage, after all ...
Having rummaged in the scraps left over from various construction repairs, I found a piece of metal profile of sufficient length and a width of 49x39 mm in depth (the standard is probably “50x40”).Approximately what is needed, although it is a pity that it is narrow - it would be wide, it would be possible to fix both working lamps. However, no, it's not a pity - all the same, there are only two nests for installing a fluorescent lamp (fig.4 ).
Approximately imagining where, what and how will be located inside the "profile", it turned out that its length is redundant and even if you install an additional cartridge for an incandescent lamp, a length of 1.05-1.1 meters is sufficient. I cut off the excess, and also cut out of a 16 mm chipboard two rectangles with dimensions of 48x37 mm for their installation in the ends of the box (fig.5 andfig.6 ).
Then install all the sockets and lamp holders on the corners of plastic (also remnants of repair) and fix them “in place” with screws and nuts 3 mm (fig.7 )
Onfig.8 you can see how it looks with the lamps, and onfig.9 It shows how the caps of the screws on the back side of the “profile” look - they almost do not protrude and, if necessary, a wooden bar can be attached on top.
Diodes with capacitors are decoupled on a piece of one-sided foil fiberglass with four foil sections left on it (fig.10 ). This “board” is fixed to the back wall of the “profile” with an M3 screw (fig.11 ). On the front wall there is a power switch.Electrical wiring is performed with insulated wire in additional fabric insulation - I don’t know the name, I found the wire, as you can already guess, right there in the garage. The mains lead goes through a hole in the side insert near the switch — seen in the upper right corner onfigure 11 .
The electronic circuit of the luminaire does not need to be set up, but if it does not always light up immediately after switching on, you can touch or run your hand over the surface of the fluorescent lamp. If it seems that the incandescent lamp shines excessively bright and at the same time still heats the body, then you can try to replace it with a more powerful one - while it will shine more dimly (fig.12 ), and luminescent is brighter, but at the latter the service life will decrease (if, of course, we can talk about the “service life” of a lamp with a burnt thread).
The LB-15 lamp of 1984, found at home, was also checked, but she did not want to work under any circumstances. But such an experiment was carried out - the lamp with the FL18S / D lamp was connected to the 220 V network via LATR and after its ignition the supply voltage was reduced to about 100 V.At the same time, the incandescent lamp was very dim, and the luminescent lamp was almost unchanged - a good enough property for use in a garage, where the voltage of 220 V is very unstable.
Andrei Goltsov, Iskitim
List of radio elementsDesignation A type Face value amount Note Score My notebook VD1-VD4
Recently I looked at a whole box of burnt energy-saving lamps, mostly with good electronics, but burnt filaments of a fluorescent lamp, and I thought - I need to apply all this stuff somewhere. As is known, LDS with burnt filaments must be supplied with rectified network current using a starter-free starting device. In this case, the filaments of the lamp are bridged by a jumper and to which high voltage is applied to turn on the lamp. There is an instant cold ignition of the lamp, a sharp increase in the voltage on it, when it starts without preheating the electrodes.
And although ignition with cold electrodes is for a more severe mode than switching on in the usual way, this method allows using a fluorescent lamp for a long time to illuminate.As you know, the ignition of a cold electrode lamp requires an overvoltage of up to 400 ... 600 V. This is realized by a simple rectifier, the output voltage of which will be almost twice as high as 220V mains input. A conventional low-power incandescent bulb is used as a ballast, and although using a lamp instead of a choke reduces the efficiency of such a lamp, if you use incandescent lamps of 127 V and include it in the DC circuit in series with the lamp, we will have sufficient brightness.
Any rectifier diodes, for voltage from 400V and current 1A, it is possible and Soviet brown KT-shki. Capacitors are also with an operating voltage of at least 400V.
This device works as a voltage doubler, the output voltage of which is applied to the cathode - the LDS anode. After ignition of the lamp, the device switches to two-half-wave rectification with active load and the voltage is equally distributed between the EL1 and EL2 lamps, which is true for an LDS with a power of 30–80 W, with an operating voltage of about 100 V on average. incandescent bulbs will be about a quarter of the flow of LDS.
For a 40 W luminescent lamp, an incandescent lamp of 60 W, 127 V is required. Its luminous flux will be 20% of the LDS flux. And for a 30 W LDS, two incandescent bulbs of 127 V, 25 W each, can be used by turning them on in parallel. The luminous flux of these two incandescent lamps is about 17% of the luminous flux of LDS. Such an increase in the luminous flux of an incandescent lamp in a combined lamp is explained by the fact that they operate at a voltage close to the nominal one when their luminous flux approaches 100%. At the same time, with a voltage on the incandescent lamp about 50% of the nominal, their luminous flux is only 6.5%, and the power consumption is 34% of the nominal.