LED lamps flicker when switched off. Why does the LED lamp blink?

Over the past couple of decades, a movement that cares about preserving the environment on our planet has become very fashionable. But such fighters often encounter completely unexpected problems and try to find out why the light is blinking. Powersave lamp when the lights are off, how does the stroboscopic effect affect human vision, why in fluorescent lamps mercury. What can I say, sometimes you have to pay for your desire to help the planet.

How does a fluorescent lamp work?

At first glance it seems that fluorescent and energy-saving lamps much better than their counterparts with an incandescent filament. But it’s worth looking a little more closely at the differences between the products.

But if we take nature specifically, then there is still the question of what exactly is more dangerous for it. Imagine that you have several small cans of mercury above your head. Introduced? So, this is not the plot of some horror movie, but the everyday reality of those who decided to try new lamps.

But don't despair, the same LED bulbs do not contain mercury vapor or other environmentally hazardous substances.

Why does the LED lamp blink when turned on?

It just so happened that she LED lamp works due to the stroboscopic effect. Roughly speaking, in a second it goes out and lights up (flickers) again about a hundred times. Due to this inconsistent glow, thousandths of a second of light and complete darkness alternate. But the human eye is designed in such a way that it does not perceive such sudden and short-term changes and records normal illumination. It just takes extra effort.

If flickering suddenly begins to be observed with the naked eye:

• You can check its frequency using a video camera; it records the slightest vibrations.
• Most likely the problem is the quality of the lamps themselves; you should look for the receipt and go to the store where you bought them.
• There may be a problem with the capacitor, which regulates the voltage and frequency of the supplied current. To fix the problem, you can either replace the existing capacitor or solder a new one.
• The problem may also be related to the wiring; remember when it was last changed, and whether there were any other “alarm bells”.

Any flicker negatively affects not only a person’s vision, but also his nervous system. There is an opinion that it is frequently changing picture underlies the formation of epilepsy.

Why does the LED lamp blink when the lights are off?

It's not very pleasant when the lamp continues to blink when the light is off. There may again be several reasons:

1. You have installed illuminated switch. For its needs, the indicator constantly consumes a small amount of electricity, as a result electrical network does not close.
2. Almost imperceptible current discharges also pass through the lamps, but this voltage is not enough to fully turn them on. Regular exposure to the capacitor gradually leads to the fact that the lighting fixture begins to blink, accumulating charge.
3. Each LED lamp is a rather complex mechanism, with capacitors or drivers that regulate the voltage supply. Any malfunction at this level can cause “light music” at night.
4. In this case, it is enough to place an ordinary transistor in parallel with the lamp.
5. No one is immune from low-quality products. The product may be defective or simply not meet quality standards. In this case, claims should be made to the manufacturer or seller.

If you want to solve the problem as quickly as possible, Screw in one ordinary incandescent light bulb parallel to the LED lamps, in most cases this helps. On the one hand, the problem seems trivial; it can be solved in 5 minutes.

But without understanding the basics, you can not only get confused for a long time, but also cause harm to your health. All work on the network should be carried out having previously de-energized the room .

Why does a switched off energy-saving light bulb blink?

Problems with energy-saving lamps most often arise for the same reasons:

• Topping the list is manufacturing defects and non-compliance with standards. Not all stores provide their customers with only the best products.
• In second place is the already familiar backlit switch.
• Manufacturers of most lamps advise that they should not be used with this type of switch.
• But if for some reason you did not read this information before purchasing lamps, you will have to change the switches in the house or remove indicators from them.
• In any case, work should begin only after you have turned off the power to the apartment on the panel.
• Alternatively, a transistor can be used again, placing them in parallel. This option is suitable if you cannot refuse the backlight for important reasons.

Saving electricity is a useful thing. But think about it, how much electricity does a pair of light bulbs consume? Now compare this with how much you spend on running a computer, refrigerator, or washing machine. It is not always worth saving on your own comfort, especially when it comes to vision.

Test the bulbs for a couple of weeks and make sure you're really happy with them.

How to reduce the burden on the environment?

Today there are many more reasonable ways to save energy:

1. Use of solar panels and wind generators.
2. The layout of the house and the location of windows in accordance with the lighting.
3. Taking into account the topographical features of the area and the wind rose.
4. Implementation of closed-loop production processes.

What can cause an energy-saving lamp to blink?

Problems and blinking of energy-saving lamps even when turned off can be caused by:

• Using switches with an illuminated indicator. A useful thing, especially if you have trouble seeing and orienting yourself in the dark. But there may be too much light.
• Wiring problems.
• Lamp non-compliance with quality standards.

You can fight each cause on your own, but it is better to take all precautions so as not to lose your health, and maybe even your life. Electricity is no joke.

It’s unpleasant when at night, instead of going to bed after a busy day, you have to try to understand why the energy-saving lamp is blinking when the lights are off. It's good that the problem can be solved, screwing an ordinary lamp in parallel. Well, or in a more radical way, by removing all energy-saving devices.

Video about blinking energy-saving lamps

In this video, electrician Ivan Matveev will talk about the reasons that cause the light to flicker when the light is turned off, and also describe how this phenomenon can be eliminated using a resistor and how to connect it:

Holders LED lighting Sometimes the light bulb may flicker when turned off. This behavior of the light source creates visual discomfort, interferes with sleep at night, and the light bulb itself fails faster. The topic of this article, why the LED lamp blinks, is aimed at identifying and eliminating possible causes of LED lighting malfunction. However, this problem is also relevant for energy-saving light bulbs. Let's try to find out further why this happens.

Let's get acquainted with the design of modern light sources

To find out why LED lamps blink when the lights are off, you need to briefly study its design. By the way, the electronic circuit led lamps similar to the housekeeper diagram. So, any of these light sources operates on 220 volt AC power. But for the LEDs located in the lamp bulb to glow, it is necessary D.C. less voltage. To do this, a special electronic circuit called a driver is placed in the lamp body. This is a kind of switching element of LEDs.

The driver rectifier is assembled from 4 diodes. Passing through it alternating current is converted to constant. However, this voltage still pulsates and to smooth it out, the electronic circuit is equipped with a capacitor. It serves as a storage unit for the current required to illuminate the LEDs. Having understood the electrical circuit, it is time to find out the reasons why the lamp is blinking.

Common Causes of Flashing

It should be noted that lamps tend to blink not only after being turned off, but also when turned on. This could be due to several reasons:

• the weak power of the driver does not correspond to the parameters of the emitter, which does not allow a full launch of the device;
• The driver rectifier is designed for low mains voltage drops. With strong pulsations electronic device can't cope;
• Some switches are equipped with an illuminated indicator. By passing current through itself, the indicator allows the driver capacitor to charge, which is why short-term flashes of the LEDs occur;
• A correctly connected switch should break the phase. If the gap is set to zero, the switched off lamp will blink in any case;
• High frequency waves often cause LEDs to glow. If there are such emitters nearby in the form of household appliances, pulsation may be observed. An elementary reason could be a mobile phone tower installed near the house.

And in conclusion, it is necessary to mention a possible defect in the light source itself, or the old lamp has simply exhausted its resource.

Methods for eliminating lamp flickering

So, it's time to find out what to do when the switched off light is blinking.

Backlight problem

Let's start with the simplest thing - a wall switch equipped with backlight. The operating principle is as follows electrical diagram simple For illumination, a small light bulb is used in the switch housing. It is connected to electrical circuit according to the principle that when the key is turned on, the current flows to the lamp, and the indicator is turned off. When the key is turned off, the interrupted circuit does not supply voltage to the light source, but at this time a new circuit is closed, supplying current to the indicator, and it begins to glow.

A small voltage passes through this indicator, allowing the driver capacitor to charge. Having accumulated energy, the capacitor gives it to the LEDs, but it is so small that it can only cause a short-term flash. Constant repetition of this process creates visible flickering of the lamps.

There are several ways to solve this problem:

1. The easiest way is to cut off the indicator wires inside the switch with pliers. The main thing is not to confuse the wires going to the backlight with the main line, otherwise you may be left without light. If you lack knowledge, it is better to install a new switch without an indicator.
2. A simple solution to the problem is possible if a multi-arm chandelier hangs on the ceiling. It is enough to screw a weak incandescent lamp into one of the sockets, which will extinguish the incoming voltage from the indicator.
3. For those who are friends with electricity, the method of installing a 2 W quenching resistor in the circuit is suitable. You need to take a part with a resistance of 50 kOhm and connect it inside the junction box or near the chandelier socket. The resistor is connected in series with the LED lamp through the terminal blocks, and a heat-shrinkable tube is put on for protection. The same effect is possible if, instead of a resistor, you connect a capacitor with a capacity of 0.5 μF, rated for a voltage of at least 400 volts.

If you still want to leave the indicator working and the LED lamps not to blink, you need to make a separate circuit for illumination inside the switch. Receiving current through other wires, the indicator will glow constantly in any position of the switch key.

Driver problem

When there is no backlight on the switch, but the lights are still blinking, the problem may be hidden in the driver. It is best to replace a product under warranty. If the warranty period has expired, and you have unusable lamps and a soldering iron at home, you can try to resolder the converter from another product. First you need to disassemble the plastic housing of the light bulb. Usually its halves are held in place by clamps. If they break during disassembly, it's okay. After repair, the body can be glued with any high-quality glue.

So, inside the disassembled case under the printed circuit board you need to find a small microcircuit. Current flows through it from the lamp base to the LEDs. This microcircuit needs to be unsoldered, and in its place another converter from a similar lamp must be soldered.

Capacitors tend to “dry out” during operation, losing their capacity. Sometimes this is the cause of the problem. Then there is no need to change the converter; you just need to solder in a new capacitor with the appropriate marking.

Electrical wiring problem

It happens that there is no backlight on the switch, a new lamp was checked upon purchase, and the home chandelier began to flicker immediately after installation. Perhaps the reason lies in the electrical wiring. Old houses have a lot of twists inside the distribution boxes instead of the required terminal blocks. They had long since oxidized, and the insulation could have cracked in many places. Here you need to think about replacing such wiring, and it’s not about the flickering of the lamps itself, but for your own safety.

If LED lamps flicker during new wiring, it means that unscrupulous electricians made a defect. There should be a break in the phase wire through the switch to the chandelier. This can be easily checked with an indicator screwdriver. They unscrew the tab from the chandelier and, with the switch off, use the tip of the screwdriver to touch the contacts inside the socket, but without connecting them to each other. If the screwdriver indicator lights up, it means that there is constant voltage coming to the chandelier. The problem is solved by changing the wire inside the junction box going to the switch.

The reason for the poor quality of lamps

The most common reason for the blinking of switched off lamps is their poor quality. This problem is sometimes observed in LED lamps and spotlights. Many Chinese manufacturers save money by putting low-quality parts into their products. Such lamps are cheaper than branded analogues and usually come without a warranty.

There may be domestic products with a good-looking body, but with Chinese filling inside. Thus, the manufacturer tries to reduce the cost of its product to increase demand. Most often, defects in such lamps are detected by inspection at the time of purchase, but it is better to give preference to branded LED light sources.

Why do working lamps flicker?

The flickering of switched off LED lamps is visible to the naked eye. If a problem occurs, it can be fixed immediately. But it happens that the lamps blink when the lights are on. This is almost invisible, however, at the subconscious level you feel discomfort and rapid eye fatigue.

The problem is the same capacitor inside the case. The small capacity does not have time to cope with the pulsation. The current passing at 50 Hz is doubled, causing the LEDs to blink at 100 Hz. There are rules according to which the pulsation coefficient of LED light sources installed in medical and children's institutions is allowed to be no more than 20%. In other cases, there are no special requirements, however, this should not be neglected, because the coefficient of cheap lamps can reach up to 60%.

You can independently identify flicker in two experimental ways:

1. Immediately after turning on one LED light source in a dark room, you need to quickly wave a regular pen or pencil in front of it. If a continuous trace is visually visible, then the pulsation is normal. Broken lines indicate a high rate.
2. The easiest way to see the pulsation is with a camera or mobile phone. By pointing the camera at the lamp from a distance of 1 m, you can see dark lines displayed on the display. They talk about high pulsation.

You can get rid of pulsation by simply replacing the capacitor with a part of larger capacity. Sometimes the dimmer can be the cause of flickering LEDs. This device is often installed to adjust the brightness of lighting. The fact is that not all LED light sources are dimmable. This needs to be clarified when purchasing lamps. Such information is indicated on the product packaging.

And finally, the cause of flickering may simply be poor network voltage. The problem can be solved by installing a stabilizer throughout the house. The device must have a surge protector. By the way, a stabilizer can solve the problem of lamps blinking due to high-frequency interference.

Many people notice that LED lamps, especially inexpensive and budget Chinese models, can flicker and blink after the power is turned off, and sometimes even during operation. But there is no need to rush to pass a “sentence” on such a light source; perhaps the problem does not lie there at all and this malfunction can be easily eliminated. Let's try to figure it out...

Causes of flicker

Ripple when LED lamps are turned off or on can occur for the following reasons.

1.Problem with backlit switches

Typically, modern glow-in-the-dark switches have LED or neon lighting installed, which simply does not completely disconnect the network. That is, the main lighting turns off, and the backlight leaves the circuit “closed”, with a small current flowing through the switch. This becomes a charge for the capacitor, that is, it charges a little and the internal circuit of the lamp turns on, it glows, then the capacitor discharges and the lamp goes out. This process occurs cyclically.

2. Low quality of the lamps themselves

The source of pulsations can be low-quality lamps, namely, non-compliance with GOST requirements for the power of the power source. This is typical for lighting devices made in China.

3. Incorrect wiring

This usually happens in houses with old electrical wiring. The switch does not break the phase wire, as it should be, but the neutral wire. As a result, the circuit is under voltage, which creates flickering.

How to eliminate flicker?

Of course, the first priority action when such a phenomenon occurs is to replace the lamps. That is, if you still have the purchase receipt, you need to go to the store to replace the lamps or get a refund.

If the receipt has not been saved or there is no desire to deal with the return of the goods, you can upgrade or replace the switch. Replacement means purchasing a new switching device without backlight.

Upgrading the switch is more difficult. To do this, it is recommended to remove the LED from it, connect an additional load to the circuit parallel to the lamp in the form of a resistor with a resistance of 50 kOhm and a power of 2 W, or lay a separate electrical wire to the lamp. Of course, in order to perform these manipulations you must have some knowledge, skills and comply with safety requirements.

In conclusion...

Good advice in this case would be to purchase lamps from trusted manufacturers with a good reputation, so that you don’t have to change or redo anything later.

You can read more about LED lamps in this article.

Watch the video on how to get rid of flickering LED lamps: