As such, damaged fluorescent lamps cannot be restored. First, the atmosphere inside is rarefied, and second, the flask is filled with mercury vapor. Fluorescent lamps are subject to mandatory disposal. The fact of loss of tightness is dangerous. Mercury poisoning does not appear immediately. Today let's talk about how to repair fluorescent lamps and chandeliers with his own hands.
How the fluorescent lamp
works Inside the fluorescent lamp, an arc is ignited. Constantly present plasma discharge. Due to this, the radiation energy is emitted in the infrared. When the rays interact with the phosphor, the latter begins to glow. The frequency of electromagnetic waves changes to the range of visible light. Usually the discharge medium is mercury vapor. For example, a droplet of this substance is present on the inner wall of the flask to maintain a specific concentration.
Electrodes fluorescent lamps of complex configuration. The shape resembles a horseshoe. The arc is inside the bulb, the two legs stick out. This is done for understandable reasons:
- The starters based on chokes proved to be the most effective in terms of price / quality.
- High inductive resistance of the circuit leads to losses due to the shift of the angle between voltage and current.
- To compensate for the effect, capacitors connected in parallel with the fluorescent lamp are used, and a starter is placed in the second branch.
This is not the only reason. For example, some ballasts that support the regulation of brightness, for operation at low currents, require a similar inclusion of active resistances. The shape of the electrodes of the fluorescent lamp is explained entirely by the features of the work. In particular, there are cartridges for chandeliers, taking into account the specified time. Under them are produced lamps with a base on two pins. Standard gas discharge often does not seem to differ from others. A standard cap - E27.The difference between the flask is mainly in the energy efficiency class( see color scale on the package).
It's time to say that a driver is enclosed inside each energy-saving light bulb and LED.This is the driver voltage supply. It is radically different for LED and gas discharge( fluorescent) bulbs. The difference in the amplitude of the voltage: LEDs require 2-3 V for steady burning. It is easy to find in the sale of tape, marking which includes the type of source. For example, SMD 3528. It is easy to find the technical characteristics of this model( data sheet), which shows a supply voltage of 3.3 V.
In gas discharge lamps, a very high potential is usually used. According to the products of the stores, it is logical to divide our object into two parts:
- The usual fluorescent fluorescent lamps.
- Bulbs with caps E27, E14, etc., are used in the usual chandeliers and lamps.
Fluorescent fluorescent lamps
Repair of fluorescent lamps is logical to start with the localization of the fault. We believe that there is a replaceable lamp in the stock, it's time to insert it and see if it will turn on. If everything is in order, the fault lies in burning the flask electrodes. Otherwise, breakage should be sought in the area of the starter and the supply circuit:
- Fluorescent Lamp Electrodes are usually made of tungsten. As the filament bulbs. But due to increased loads, the heat-resistant metal is additionally coated with alkali metal pastes. As you work, the protective layer is consumed: from overheating it dries, crumbles or evaporates. As a result, over time, formed the bare areas of tungsten, which will not fail to burn at the first opportunity. As a result, the arc extinguishes. This causes an instantaneous increase in voltage, which causes the starter to trigger. The fluorescent lamp will blink, but the arc does not light up, the circuit is open. The product can not be repaired, but you can apply the scheme shown in the figure. It is simple and allows you to raise the voltage to about 450 V. Below we consider how the driver works, but for now, we note that as the fluorescent lamp ages, the glass gradually blackens along the pedestals. This is caused by the gradual burning of the electrodes.
- When a new fluorescent lamp is off, it's time to watch the driver. It should be noted here that quite a few schemes are known, it is difficult to give unambiguous recommendations on what to do and how exactly. Driver designs are diverse, ranging from conventional resistors to electronic circuits that supply a fluorescent lamp with a voltage of increased frequency( up to 20 kHz).As a result, the so-called stroboscopic effect arising due to frequent blinking is blocked. A typical fluorescent lamp flickers with a frequency of about 100 Hz( double industrial), which is simply unhealthy. It must be said that electronic ballast is more often used in light bulbs on the E27 base and the like. As for our case, for the most part a throttle circuit with a compensating capacitor is used. The starter is switched on parallel to the lamp.
Non-working fluorescent lamp switching circuit: take everything from life!
The figure shows a possible circuit for switching on a non-working fluorescent lamp. Meaning: the starter is no longer there, and the electrodes will constantly be at a high voltage of 450 V. This will generate a glow discharge. Principle of operation:
- At the initial moment of time, a C4 capacitor is charged through a positive half-wave through diode D4 to a mains voltage of 220 V x 1.41( the root of two) = 310 V. Plus accumulates on the bottom plate( according to the diagram).
- At a negative half-wave, the charge gets capacitor C3 through diode D3.The potential difference on the plates reaches 310 V.
- Now the fluorescent lamp is under a total voltage of about 600 V, enough for the formation of a glowing arc.
- Capacitor C4 is discharged through diodes D1 and D3, and C3 through D2 and D4.
Assignment of capacitors C1 and C2 at the entrance to the decoupling of the power network from the high-voltage part, in the formation of the correct path of charging and discharging the capacitances C3 and C4.It is clear that the elements must withstand modes of operation. The operating voltage of the capacitors is not lower than 350 V. S1 and C2 are better to choose from a number of paper ones, and C3 and C4 are mica( jelektro.ru).Diode requirements are similar.
Fluorescent Lamp Startup System The standard fluorescent lamp switching circuit looks like this:
- A 220V power supply is supplied to one branch of the double electrodes. The choke and the lamp electrodes are connected in series with the capacitor to neutralize the reactive part of the choke.
- A starter is placed in the second branch. It is a parallel-connected contactor and a low-power discharge lamp.
At the initial moment of time, bypassing the choke, the mains voltage is applied to the starter. As a result, the discharge lamp begins to glow. Its current is relatively small and is 20 - 30 mA.Due to this, the heating of the bimetallic relay starts, which closes at the right moment. Then the voltage at the choke begins to grow rapidly, but the current is strongly limited by inductive resistance. Gradually, due to the lack of current, the bimetallic relay cools down, as a result, the circuit is broken.
Then follows a sharp redistribution of potential along the circuit. There is a sharp voltage drop across the choke. Both its windings are wound on a single core, there is a resonant response surge of EMF( coils due to the direction of the coils create a folding effect).The increased voltage pierces the fluorescent lamp, the glowing arc lights up. This leads to the appearance of light. Now look what happens when the electrode burns out:
- The arc goes out, a chain break is formed.
- All voltage is applied to the starter.
- The discharge lamp turns on and the bimetallic relay starts to heat.
- The chain closes, as at the start, then breaks.
- The arising EMF is trying to set fire to a fluorescent lamp, it can be seen how the arc jumps.
- Due to the brevity of the moment when the voltage is increased, the flash lasts a moment.
- Everything is repeated.
The defective fluorescent lamp blinks. Smart heads have guessed constantly to feed it with increased voltage( 600 V) so that the arc does not extinguish. It is clear that such a mode is considered to be too tense, when connected according to the scheme given in the previous section, a broken fluorescent lamp will not work for a long time. As for the ignition scheme, its analysis is carried out as follows:
- Repair of fluorescent chandeliers begins with a check of the throttle. Need to call him. The power is turned off, you do not need to remove this element from the circuit. Usually, a fluorescent lamp choke is manufactured in the form of a solid parallelepiped and has two leads.
- A compensating capacitor is unlikely to cause a breakdown, it only lowers the reactive part of the resistance. It is permissible to ring for a short circuit( if you constantly knock out traffic jams).
- The starter can be checked using a standard power outlet. Usually in the case there is a window through which they observe the decay of the discharge. At some point, the contacts will close. To track this, sequentially with the starter, turn on the usual incandescent light bulb. The process looks like this:
- At first nothing happens.
- Then the light blinks and goes out.
- The cycle is repeated.
All this takes a little time. Much faster than the story about the repair of fluorescent lamps and chandeliers with his own. As a result of the measures taken, the malfunction will be localized.
Repair of halogen light bulbs
Sale in the store bulbs on the E27 base and the like is not always fluorescent. Here is the difference in what is the source of light. In our case, it should emit phosphor. And if frosted glass is simply used, this is a different type of light bulb.
Inside the base there is a driver( voltage driver).If the light bulb breaks, it's time to disconnect the threads with the base and see what's inside. It will take a small slotted screwdriver( even the indicator will come off).The bulb is removed, inside the usual switching power supply, as shown in the picture. To troubleshoot fluorescent fixtures, you should be well versed in electronics.
The circuit consists of diodes, resistors, capacitors, one choke, a pulse transformer and a pair of transistors. The principle of operation described above, with regard to the bulb, it differs from its older relatives in thickness and shape. No more.
Before testing, take the time to draw a circuit of a printed circuit board on a piece of paper; a lot will become clear. Installation is made in a single layer, we do not see much difficulty. Element values are written here, on the printed circuit board, as usual in foreign electronics, there are explanatory signs.