How to test an energy-saving light bulb with a multimeter. How to disassemble and repair an energy-saving lamp? We determine the degree of damage and repair the energy-saving lamp

Has the economy lamp burned out? The easiest way is to throw it in the trash, but you can make… another one out of it, and if you have accumulated several burnt out lamps, then you can do…. repairs.

If you have held it in your hands at least once, then this article is for you.

You can turn on the lamp daylight up to 30 watts, without a starter and choke, using a small scarf removed from our economy lamp. At the same time, it will light up instantly; when the voltage drops, it will not ‘Blink’.

This lamp burns out in two ways:

1) electronic circuit is on

2) the filament burns out

First, let's find out what happened: Here is the housekeeper. Using a screwdriver, pry it in the places indicated by the arrows (assembled with latches)

You need to parse it like this:

Turn off the flask:

We bite off the power wires. We call the glow of the flask (to decide whether to throw away the flask or not)

I was unlucky, both filament coils burned out (for the first time in my considerable practice, usually one, and when the circuit burns out, not even one). In general, if at least one flask burns out, we throw it away; if not, then it is working, and the circuit burned out.

We adjust the working flask for storage (until the next burnt housekeeper) and then to working diagram we hook the flask. So out of several we make 1, or maybe more (depending on your luck).

And here is an option for making a fluorescent lamp. You can connect it like a 6-watt lamp from a “Chinese” lantern (for example, I wrapped it with plastic from a green bottle, and hid the circuit in a burnt-out charger for a Nokia mobile phone and it turned out to be a cool backlight for an aquarium):

and a 30 Watt fluorescent lamp:

Yeah, I’m not a writer…..but oh well.

Energy-saving lamps help save on utility bills, in addition, you can choose the most comfortable color spectrum, which does not tire your eyes during work, which can relieve tension in the recreation area, and each type of ESL will allow you to choose exactly the lighting option that is suitable for a specific indoor zones. Their declared service life can exceed 10 thousand hours, which is ten times longer than the life of a conventional incandescent lamp. But. Sometimes ESLs stop working, so paying five dollars for a new one is not very pleasant.

Typical lamp malfunctions

That is why, before disposing of the lamp, you can try to restore it. Repair only energy saving lamps do it yourself is possible when their design and characteristic faults are known. We will consider this issue right now.

There are no difficulties in repairing ESL if you confidently hold a soldering iron in your hands and have basic skills in reading circuit diagrams. But it may not even get to the point of repairs and circuits, since very often lamps from manufacturers in the mid-price category may simply have manufacturing defects. This is expressed simply - the lamp blinks when turned on or goes out for no reason.

ESL repair and circuits

But first, briefly about the design and architecture of the lamp. Each ESL has a spiral or U-shaped flask, an electronic control unit and a base. The ends of the flask are connected to the spirals on the board electronic unit, and it includes:

medium power transistors;

chokes;

• high voltage capacitors;

  high frequency transformer.

The most vulnerable elements of the circuit may be the heating coils, and their overheating can lead to failure of other board elements.

Ballast repair and diagnostics

ESLs of the lowest and mid-price categories can be assembled without the use of soldering, and the wires are secured using latches. Naturally, after some time the contacts burn out or oxidize, and to repair such lamps it is enough to either solder the conductors where they are attached to the base, or simply clean them of carbon deposits or oxide due to corrosion.

In addition to this reason, there may be another malfunction that leads to the blinking of the lamp - a burnt out filament. A lamp with a burnt filament may not turn on for a long time and may blink. To eliminate the malfunction, you will have to open the case and separate it from the base with a knife or a sharp screwdriver. After gaining access to the board, you need to check the integrity of the ignition coil. Its resistance should be within 10-15 Ohms, but if the thread does not ring with the tester, it has burned out.

Possible problems with the lamp

You don’t even have to check the filaments with a tester; if the glass of the bulb is burnt near the base, you can safely change them, but they will be suitable in terms of resistance. In cases where the lamp simply blinks when turned on, the capacitor may fail. The largest capacitor in the circuit, 400 V, may swell, which means that it has failed. Naturally, you need to replace it with a similar one at nominal value.

A failed capacitor can, in turn, lead to burning of the contacts on the transistors; sometimes they can explode, and this is immediately noticeable when the lamp is opened. In these cases, the transistors are also replaced with new ones (as a rule, these are 13003 transistors). Here are some more common problems with ESL:

breakdown of the capacitor, which is installed between the filaments, it is replaced with the corresponding nominal value (3.3Nf, 2kV);

ESLs of poor quality may blink or not turn on at an air temperature of about 3-5 degrees below zero, or above +40-45⁰С;

the lamp may lose its glow intensity over time, so a low-quality phosphor may show only 50% efficiency at the end of its service life.

When replacing transistors or repairing ballast, it is necessary to take into account that the rating of the transistor depends on the power of the lamp. The table shows the dependence of the names of the transistors used on the ESL power.

ESL modernization

For lamps of poor quality, it is recommended to carry out some upgrades that will help extend the life of the lamp. To do this, an NTC thermistor is installed in the gap with the filaments. It will help limit the amount of inrush current and, as a result, eliminate the possibility of burning out the filaments. There is one important point - the thermistor will heat up, so it cannot be placed directly near the ballast.

Finally, it would be a good idea to make several ventilation holes in the plastic case. This will improve air circulation and will also help maintain a normal board temperature. True, lamps with holes can no longer be installed in wet areas. We hope that these tips will help extend the life of an energy-saving lamp and save a couple of hundred on the purchase of a new lamp. Productive work!

Today, manufacturers of lamps with energy-saving parameters leave no choice at all to ordinary consumers who choose between incandescent and ESL lamps. The choice in favor of the latter is obvious. Now there are almost no apartments or houses left where energy-saving lamps are installed. And this is not to mention office or industrial premises. ESLs can save up to ninety percent of electricity per year. Many of us are interested in the question of whether it is possible to repair energy-saving lamps with our own hands.

Repair of energy-saving lamps or how to assemble one lamp from two

In most cases, manufacturers indicate 8000 hours in service life. continuous operation. But practice shows that most often light bulbs do not last for the specified period. And this comes as a rather unpleasant surprise, since they are not cheap.

But this shouldn't be a big disappointment, since energy-saving light bulbs turn out to be quite easy to repair. It’s not necessary, because out of several non-working ones you can make one working one.

Is it worth starting renovations?

First, you need to find out whether it is even worth undertaking to repair a burnt out light bulb and whether it will be justified. Many experts say that it all depends on how many lamps you want to repair. If we are talking about one light bulb, then it is better not to take it at all. The only exception is the situation when you have several non-working light bulbs, which will become the basis for one working one.

Such a light bulb, like any other, should also be distinguished by its operating life. If your lamp stops shining after a year and a half, and its service life is 10,000 hours, then it may be cheaper. After all, you have to spend money on spare parts, travel, and also lose your own time.

After prolonged use, ESLs lose the ability to turn on quickly. They work a couple of seconds after switching on. You also need to take into account that old light bulbs over time begin to produce more heat than light. Another significant drawback of old light bulbs is the wear and tear of the fluorescent bulb, which fades over time and the lamp becomes not as bright as it was.

To summarize all of the above, you should start repairing light bulbs only when you have several non-working ones on hand. Practice confirms that out of twenty you can make about 5 lamps. If you still decide, then ask your friends or family - they will probably help you with old light bulbs.

How to assemble one lamp from two

To understand what needs to be repaired and how, let’s first look at what it’s made of. Any gas-discharge fluorescent lamp consists of three parts:

• flasks;
• electronic board (ballast);
• base

If the bulb of your non-working lamp has defects (in the form of cracks, for example), then it can no longer be repaired. In other cases, if you have the desire and skills, you can fix it.

Most often, lamps stop working because the filaments burn out or as a result of a breakdown of the electronic board. Before repairing, the lamp must be disassembled and the cause of the breakdown identified. To do this you need to do some steps.

The first step is to disconnect the base from the burnt bulb. The fastenings used are the same as in the housings of mobile phones or remote controls. remote control. Therefore, be extremely careful. The best tool here will be a screwdriver with a wide and thin end. Your main task is not to completely break the base.

The connecting wires are usually short in length, so do not disconnect them too abruptly. In most cases, the first latch is the one located under the inscriptions with the characteristics of the light bulb. You need to insert a screwdriver into this place and turn it gradually. After this, the lamp should split into two parts.

The second stage will be the process of disconnecting the wires from the filaments. There are two pairs of conductors in the bulb - they are the filaments. If you do not disable them, you will not be able to determine functionality. It shouldn't be too difficult for you to disconnect them, since in most cases they are not soldered, but simply wound on top.

The third stage of disassembly and testing will be the diagnosis of filaments. To do this, you need to ring two threads. This will allow you to understand which of them is faulty. In most cases, the lamp consists of two spirals, which have a resistance of 10 to 15 ohms. Based on the results of the call, you can find the cause of the breakdown. There are two options here:

• ballast is damaged;
• one of the filaments has burned out (lamp with a damaged filament).

Depending on the type of breakdown, you will have to perform various manipulations. Let's consider both of these options.

Repair of system components

Restoring a lamp after the failure of the electronic ballast involves identifying all burnt-out elements, as well as those that are still suitable. After disassembling the light bulb, inspect the board for visible external defects on all sides. Also inspect each of its components. If during inspection you do not find any visible defects, then proceed to testing its main modules, namely:

• limiting resistor;
• diode bridge;
• filter capacitor;
• high voltage capacitor.

The fuse is installed into the light bulb by soldering it to the contact on the base. It is already attached in heat-shrinkable material. Most often, it suffers after a short circuit, after which the entire circuit breaks. When a fuse blows, a resistance of 10 ohms is considered normal, while infinity is considered abnormal. Please note that when cutting wires after a fuse has blown, do so as close to it as possible. This way you will provide yourself with a supply of wire to solder the new resistor.

The main function of the diode bridge is to rectify the 220 V voltage. It is based on four diodes. You can ring them on the spot; this does not require soldering them.

The filter capacitor breaks down first in lamps that are made in China. It serves to rectify voltage. The burnout of this element is initially accompanied by unstable operation of the energy-saving light bulb - it makes extraneous sounds, does not turn on immediately, and so on. After failure, you may notice external defects: swelling, darkening, drips, and so on.

The high-voltage capacitor is designed to create a pulse, which, in turn, creates a discharge in the bulb itself. The failure of this particular element causes most breakdowns of energy-saving lamps. You can determine the malfunction without ringing. The lamp will not light up, and the filaments will create a glow near the electrodes.

Once you have checked the main modules of the board, move on to the additional ones: transistors, resistors and diodes. It should be noted that with soldered transistors you will get incorrect multimeter readings, so they must be desoldered first. Also keep in mind that one detected failure does not exclude the possibility of another, so you will have to check all elements.

But there is a method that will allow you to avoid soldering the transistors. You just need to measure the resistance of the elements on the working board and compare them with the non-working ones.

Spiral repair

Often light bulbs stop working for other reasons - failure of the filaments or circuit. A hint here will be the darkening in the place of the burnt spiral. To check, measure their resistance. If one of the threads burns out the right decision will get rid of the flask. Moreover, the board can be used in the future to repair other ESLs. But thrifty users were able to find a way out of the situation here too. You just need to short-circuit the leads of the burnt out spiral.

Do not expect that this will allow you to again enjoy thousands of hours of operation from the corrected lamp. A lamp will not last long on one working coil. Here's what needs to be done.

First of all, disconnect the spirals and determine the performance of each of them (read how to do this above). Using a multimeter, you can find a non-working thread (it will also show signs of burnout). If the second thread is working, you will simply have to bypass the non-working thread with a resistor of the same value as the working one. This step is mandatory because the circuit will not work without the bypass.

That's all. As you can see, repairing energy-saving lamps at home is not easy, but possible. If you yourself have encountered the restoration of such light bulbs, share your comments under this article.

Before we undertake the repair of energy-saving lamps, let's consider some philosophical issues.

Do I need to undertake repairs to an energy-saving lamp?

First of all, you need to honestly answer this question for yourself, calculate everything (money and time), and only then move on to the technical side of the issue. I hope my article will help you make the right choice.

So, let’s take the price of a normal new energy-saving device to be 150 rubles. What does it mean? If a lamp breaks after a year of operation, I think there is no point in repairing it. First of all, because the price necessary details- about 50 rubles, plus the cost of repairs is about 100 rubles. By repair cost I mean the cost of effort and time spent.

And most importantly, the resource and quality of the lamp’s operation steadily decreases over time, and this primarily applies to the luminescent bulb. It darkens at the edges, the overall brightness decreases every hour. As in the photo below.

The bulb of a compact fluorescent lamp darkens at the edges. On the right is an incandescent lamp, it burns without problems. Photo from the article.

The efficiency of such a lamp decreases - it heats up more, but shines less. Another unpleasant effect appears - the lamp “thinks” before turning on. And it turns on after a second or two, and does not flare up immediately, but after a minute or two.

This sometimes infuriates me when I’m in a hurry and have to wander around in the dark.

Conclusion - if an energy-saving lamp breaks after a year of operation, repairing the lamp is not economically viable. Perhaps some of it will be used for spare parts, more on that later.

Moreover, now that good LED lamps can be purchased for 90-120 rubles, there is no point in repairing CFLs at all.

Well, this article is for the brave and desperate.

Terminology and operating principle

Let's expand our consciousness.

Luminescent, compact, energy-saving, with electronic ballast, with an inverter - all the same, the essence is the same. Moreover, such lamps have absolutely different designs. For example, there may be a G9 base, like a halogen lamp, or a regular one - E14, E27, E40.

The lamp may be separate and inserted through sockets, and the electronic ballast may be separate. This applies primarily to linear or tubular lamps. An example of such a design is Armstrong-type lamps for office premises.

That is, there are different designs, but the essence is the same.

It has recently become fashionable to call all these lamps “energy-saving”, but the essence is the same. Why do they call it that - because at the same brightness they consume about 5 times less electricity. According to the sellers, one can argue with this.

By the way, there is often confusion between the concepts “ lamp" And " lamp“. In this case, I separate these two concepts like this. Lamp- This is a flask with a spiral filled with gas. A lamp– this is a lamp plus a circuit that ensures ignition and combustion of the lamp. This circuit can also be called - electronic ballast, electronic ballast, inverter, power supply, generator, etc.

Electronic ballast electronic ballast. Four more lamps - and there will be an Armstrong type lamp

We won't go into details. But the operating principle is the same.

There is a rectifier that produces from 220V 50Hz constant pressure 300…315 Volts. Next, a generator of high (compared to the input) frequency (about 10...15 kHz) operates at this voltage. The generator produces voltage that powers a tube filled with gas and coated with a special compound. You can go deeper, but this is also on other sites.

In the meantime, it is only important to know that an energy-saving lamp fundamentally consists of two parts - electronic unit And glass part(tubes or flasks).

Previously, instead of electronic ballast (electronic ballast, electronic ballast), a throttle and a starter were installed, but this is a completely old story.

Causes of breakdowns of energy-saving lamps

The reasons for CFL failure are commonplace, as in any electronic equipment, namely:

• Overheating for various reasons,
• Poor quality components,
• Frequent on/off
• Problems with the supply voltage (low/high, low).

But here’s another reason that doesn’t seem obvious the first time; my regular reader Vladimir sent me a description of this problem:

What's new in the VK group? SamElectric.ru ?

Subscribe and read the article further:

Quite unexpectedly, CFLs turned out to be very sensitive to the quality of connecting elements and cartridges. This is partly understandable contacting elements were developed for incandescent lamps with their high current consumption, and switching to CFL could result in an unstable connection. The fact is that any element that provides mechanical switching of an electrical signal, for example, a relay, has two characteristics - “maximum” and “minimum” current.

The first is clear, it is determined by the area and shape of the contact, and the second parameter is less common and less known. It is laid down when designing the type of coating of contacting surfaces. If nothing special is done, an oxide film forms on the surface of the contacts, which increases the resistance in the on state, up to an “unstable connection”. Subsequently, “carbon deposits” form at this place, which leads to an increase in the defect.

A poor-quality connection leads to surges in the charge current of the smoothing capacitor of the electronic ballast of the CFL, which reduces its service life and abruptly changes the operating mode of the entire CFL, and this can lead to worse consequences - combustion of the electronics or destruction of the filament circuits in the bulb. And these are not just words, I myself encountered the manifestation of this defect. In one room I have a lamp with five arms for E14 (“minion”) lamps. A fluorescent lamp burned out in one of them, I noted “it happens” and forgot. But a month later, in the same socket, a completely new lamp became unusable. This seemed strange, but there was no desire to figure it out, and the lamp was simply replaced.

Alas, about a month later the story repeated itself again, which was extremely strange, because exactly the same lamps were installed in the neighboring horns and no complaints were made against them. The only thing that could cause a problem was the cartridge of the ill-fated horn. An ordinary carbolite cartridge, one of three that were on the lamp (the original ones were destroyed by exploding incandescent lamps, which prompted the transition to CFLs). A thorough external inspection did not reveal any defects, the wire connection is reliable, the contacting surfaces under the lamp are clean and without any traces of carbon deposits. However, so many lamps burned out in this cartridge for unknown reasons, which cannot be ignored.

Well, I degreased the contacting surfaces, and then sanded them with fine sandpaper. After preventative maintenance, the defect did not manifest itself; at the moment, the lamp in this horn has been working for more than a year. I'll try to assume that the culprit was a thin layer of fat on the contact surface, which led to an unstable connection. If there had been an incandescent lamp in this place, then everything would have functioned normally - a fairly large current from the lamp would break through the oxide layer and a reliable connection would be established.

The problem emerged specifically with CFLs, in which the current consumption is much less, and the current itself is not constant over time. I would also like to emphasize - pay special attention to the quality of connecting elements and sockets when using lamps with low current consumption, especially if the operating life of these lamps is suspiciously short. Not everything is determined by the quality of the CFL; the source of the problem may lie outside it.

What breaks in energy-saving lamps

In this section I will describe how what needs to be analyzed before how to fix an energy saving lamp.

1. Open the lamp.

As a rule, the place of opening is where the inscription with the name and technical parameters of the lamp is applied. The ends are also located there. glass flask, if the flask has several kinks.

How to disassemble a CFL. At the opening point, pry it off with a flat screwdriver.

After opening the lamp we see its structure:

2. Flask.

If there is noticeable darkening at the ends, then the flask can be safely thrown away. Also, the flask can be considered unusable if it has worked in the lamp for more than 2 years.

3. Filament

If the condition of the bulb is normal, we test its filaments with an ohmmeter. The resistance should be several ohms. The more power, the less resistance.

Energy-saving lamps also have filaments; they are needed for initial ignition. Marketers don’t like to mention this fact.

4. Electronic ballast.

The spiral and bulb are normal, good luck! R Repairing an energy-saving lamp may make sense.

We inspect the electronic ballast board. As a rule, if something is burned there, it is immediately visible. Especially burnt resistors. Although, resistors can fail without visible consequences. As a rule, resistors in the emitter and base circuits, as well as transistors, burn out. If something else has burned out, I don’t recommend taking on repairs. Or you’ll just have to change everything on the board, spending a lot of time.

Electronic ballasts from compact fluorescent lamps. Some parts have already been pulled out...

5. Filter capacitor.

This is the same capacitor that smoothes out the ripples of the rectified voltage. When, some say that this particular capacitor is “to blame”. If it is swollen, it must be changed. It is better to choose a capacity one step larger. For example, it was 4.7 uF - set it to 6.8. But this is not important. The operating voltage of the capacitor is the same as the old one, or more if it fits into the case.

6. Installation.

And of course check the fuse, installation integrity, soldering, mechanical damage. Of course, it is better to do this first, immediately after opening.

Now we need to make a decision. I only took on repairs when I had a lot of the same type of burnt-out lamps on hand, so the repairs are much more fun.

Lots of broken lamps. The renovation makes sense.

As practice shows, out of 10 lamps broken due to natural reasons, the normal output is 3-4 pieces.

Energy saving lamp circuit

Before undertaking repairs, you need to consider the fundamental electrical circuits energy-saving (compact fluorescent) lamps, which are listed in a separate article. To be aware of how the lamp works.

Repair of energy saving lamp

What do we see in these diagrams? If there is one lamp in the lamp, then there are at least 2 transistors. So they burn out and pull the resistors with them.

To repair a lamp, you must first determine which resistors have burned out. As a rule, now it is used to indicate the resistor value color coding, without this there is no way to repair.

For example, the last circuit, number 17. The 1 Ohm and 20 Ohm resistors burn out there, for a total of 4 resistors.

With transistors it's a little more complicated. The power of the entire lamp (lamp) depends on the power of the transistor. Transistors are used high-voltage, type MJE or analogues. Here is an approximate table of correspondence between the transistor model and lamp power:

• MJE13001 (power up to 7 W)
• MJE13002 (power up to 10 W)
• MJE13003 (power up to 15 W)
• MJE13004 (power up to 20 W)
• MJE13005 (power up to 40 W)
• MJE13006 (power up to 75 W)
• MJE13007 (power up to 100 W)
• MJE13008 (power up to 120 W)
• MJE13009 (power up to 150 W)

The capacities are approximate, of course it is better to take with a reserve.

Datasheets for transistors and what else I dug up on the topic, as usual, I post below. If anyone needs it, I can publish a method for testing transistors. And also - at different manufacturers The same transistors can have different pinouts; you need to check them before soldering.

Now for the prices of parts. 4 low-resistance resistors with a power of 0.25 W will cost at least 8 rubles. We take retail prices. Popular transistor MJE13003 – 25 rubles, retail again. Total - 33 rubles for parts to repair a lamp with a power of up to 15 W.

But it will only make sense if this business is put on stream, and if the lamps for repair are free. For example, in an enterprise where, for example, 100 lamps can be used in one workshop.

An example of a refurbished lamp.

On occasion, I recently dismantled the CFL I repaired back in 2010.

More precisely, I couldn’t figure it out, but she “figured it out” herself - the latches of the case popped out, and the bulb hung on the wires:

Here's what we have inside:

It can be seen that resistors and transistors have been replaced (judging by the soldering).

In this case, the resistors, due to the lack of the necessary values, are selected so that instead of one 10 Ohm resistor in parallel there are 2 x 22 Ohms, and instead of 51 Ohms - two x 110:

Let me remind you that absolutely the same applies to electronic ballasts for lamps with replaceable lamps.

Well, if the lamp does not light up after replacing resistors and transistors, throw out the electronic ballast. Although, after a test switch-on, I will question the integrity of the new soldered parts.

But one of the options for using electronic ballast from a compact fluorescent lamp is to illuminate an ordinary linear (tubular) lamp.

Elevate it and you will get a wonderful lamp.

Download reference data for transistors for fluorescent lamps

Now – I’m posting files on the topic, as usual, everything can be downloaded for free and freely.

A visual inspection of a lamp does not always allow one to draw a conclusion about its suitability or unsuitability. There are cases when the tungsten filament is not damaged, but the light bulb in the lamp does not light. Things are even more complicated with LED or fluorescent lamps. There are several ways to determine the cause and thereby confirm or refute the malfunction of the lamp. You can learn how to do this from this article.

The simplest way

The simplest diagnostic method is suitable for both incandescent light bulbs and fluorescent and LED lamps. He suggests screwing the suspicious light bulb into another lamp and turning it on. Unfortunately, this is not always possible. Sometimes the threaded part of the base is made with a deviation from standard size and when screwed into the cartridge, it does not close both electrical contacts. Or there are no more lamps with the exact same socket in the house.

When buying a light bulb in an electrical goods store, many people paid attention to how the seller checked it using a tester. The tester body has several connectors designed for diagnosing light bulbs. different types: incandescent, fluorescent and halogen. Its task is to check the integrity of the conductors inside the lamp, as evidenced by the sound signal. This same operation can be done at home using a multimeter or a multifunctional indicator screwdriver.

Checking with a digital tester

In dialing mode

Each multimeter has a continuity mode, with which you can check the integrity electrical connection. This mode is indicated on the instrument panel by a special symbol. To check the functionality of the light bulb:

• set the switch to the dialing mode (checking for a break);
• touch the central contact with one probe and the side contact with the other (for incandescent lamps with a threaded base).

If the lighting device is working properly, the tester makes a sound, and a number within the range of 3-200 Ohms appears on the LCD display.

Before each measurement, you should short-circuit the probes with each other to ensure that the tester's measuring circuit is working properly.

Compact fluorescent (CFL) and LED lamp you can’t test this way, due to the presence inside electronic circuit. Separately, you can check the suitability of only the CFL glass spiral. To do this, you need to carefully separate it from the base part and ring two pairs of wire leads going to the electronic ballast board.

In resistance test mode

There is another, more accurate, method for diagnosing spiral lamps using a multimeter. They can not only determine the suitability of a light bulb, but also find out its resistance. Why is this necessary? For example, the factory imprint on the bulb of an incandescent lamp has been erased. Therefore, its power is unknown. This method will help solve this problem.

Now let's talk about how to test a light bulb with a multimeter in resistance mode. To do this, you need to move the switch to a position with a limit of 200 Ohms, and then touch the electrical contacts of the lamp with the probes in the same way as in the dialing mode. In this case, there will be no sound signal and the LCD will show the resistance value in Ohms. If “1” remains on the display, then there is a break inside the lighting fixture.

Based on the measured resistance of the coil in a cold state, one can draw a conclusion about its power. The table we compiled shows data on the main types of lamps used in everyday life.

During measurements, you should remember that due to poor contact of the probes with the tester, the result obtained may differ from the table one by several ohms.

Checking with an indicator screwdriver

To check whether a light bulb is working properly at home, you do not need to have a multimeter on hand. It is much faster to do this using a multifunctional indicator screwdriver. Its difference from a conventional indicator is the presence of a coin cell battery inside the case. The functionality of such a screwdriver is checked by touching its metal contacts at the ends with your fingers. In this case, the indicator LED inside it should light up.

The sequence of actions for checking an incandescent lamp is as follows:

1. Take the light bulb in one hand, touching the thread (side contact).
2. Take an indicator screwdriver in the other hand and touch the central contact of the lamp with a metal rod, and touch the end of the screwdriver with your thumb. Thus, the circuit is closed through the screwdriver, the lamp and the human body. The entire test takes just a couple of seconds.

Finally…

In conclusion, it is worth noting once again that due to the complexity of the design, it is not possible to determine the performance of an LED or compact fluorescent lamp using a multimeter or an indicator screwdriver. The only way to check such light bulbs is by applying operating voltage to their contacts.

The above methods for checking household light bulbs will also work in the case of car lamps with filament, as well as T8 fluorescent fluorescent lamps.

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