When the LED lamp is turned off, it glows dimly. Why does the LED lamp glow dimly when the switch is off? Dim light - what to do

The design of LED lamps differs significantly from the design of conventional incandescent lamps. This is often the explanation for LED lamps burning when the switch is off.

LED lamp device

Despite the variety of models and the difference in technical solutions depending on the manufacturer, each LED lamp has the following main components:

• base;
• frame;
• LEDs;
• driver.

As in conventional lighting fixtures, the base is used for fastening, and the body is used to accommodate the main elements. Some of the lamps are equipped with radiators for cooling. Lighting sources are LEDs - semiconductor elements that convert electrical energy into light radiation. The voltage they consume is significantly lower than the usual 220 V, and therefore the power is much less than that consumed by ordinary light bulbs. This is the basis for savings in the operation of LED lamps. But to create the required voltage, it is necessary to use special converters (drivers) that lower it to the required value. This is where the main differences appear. The converter is a complex device consisting of electronic components: a diode bridge, resistors, transistors, capacitors, chokes, and sometimes transformers.

Why do LED lamps work after being turned off?

The glow of the device when it is turned off can be caused by several reasons.

Operation of the capacitor included in the driver

The ability of an LED lamp to continue to work when the light is turned off causes quite a logical surprise among many consumers. Electricity is not supplied, but the device is functioning. The next question then arises: where does the food come from? Some electronic components are capable of storing electrical energy. A capacitor is one of them. It is part of the LED lamp. While it glows from the network, it accumulates electricity. When the electricity is completely turned off, the capacitance releases the accumulated energy and acts in this case as a source of voltage. It is because of this detail that LED lamps may burn briefly after being turned off.

The capacitance is considered reactance, since it is capable of returning consumed power to the network. If it were not an integral element of LED lamps, then they would not be able to shine when the electricity was turned off. Similar to how ordinary lamps stop working after being turned off, because they are very simple devices that do not contain reactive elements. When the electricity stored by the capacitor runs out, it stops being a power source and producing voltage, as a result of which the LED lamps stop receiving energy and go out. In this case, the accumulated charge is only enough for a few seconds to maintain the operation of the device after switching off.

It is unlikely that this couple of moments of glow needs to be eliminated. Moreover, capacitance plays an important role in power conversion: it smoothes out ripples in voltage after a decrease.

LED switch

If the LED lamp glows for a long time after being turned off, then the reason is different. The lighting fixture may be used in conjunction with a switch. Very often they use an LED switch, which, in addition to the main function of disconnecting the electrical circuit, also performs an additional function: it lights up when the lamp is turned off. To do this, it is equipped with an LED, which is supplied with voltage when the light bulb is not working. Thanks to the parallel connection, no power is supplied to the lamp. That is, at this moment, an electric current passes through the switch LED, which charges the above-mentioned capacitor. When the latter accumulates a sufficient amount of electricity, it begins to send it to the network, acting as a power source. LED light bulbs receive this electricity and glow. After the reactive element is discharged, there is no energy and the light bulb stops burning. The capacitor is then charged again and the process repeats. It will light up and then go out, which visually looks like blinking.

Important! This drawback disrupts the normal operation of the device, increases the amount of electricity consumed, and shortens its service life.

It is necessary to consider what can be done to eliminate the described defect.

Ways to eliminate blinking

1. The easiest way out is to replace the switch with another one that does not light up. Once the entire circuit is open, it will not glow, so no voltage will be required during the shutdown, and no current will flow to recharge the capacitor. The advantages of this method are speed and simplicity, but its disadvantage is the additional financial costs of a new switch.
2. Self-removal of the backlight from the switch. In this case, you will need to disassemble the lamp body, unscrew or use wire cutters to bite off the wire that goes to the resistor and LED.
3. Adding a shunt resistor. This method is suitable for those who want both the LED light and the switch to glow in the dark. But its implementation requires some technical steps. First of all, you will need to purchase a resistor with a resistance of about 50 kOhm and a power of 2-3 W, this can be found in any radio parts store. Then you need to remove the lamp shade, and plug the wires coming from the resistor into the terminal block to which the network wires are connected.
   

   Important! Before starting work, you should de-energize the circuit by turning off the machine, and when working, you must follow safety precautions. Do not do this work yourself if you are not confident in your abilities. Working with high voltage is dangerous to life!

   As a result, the resistor will be connected in parallel with the lamp and, when it is turned off, the current flowing through the switch LED will also flow through the resistor, and not through the driver capacitor, so it will not have the opportunity to recharge. As a result, the LED lamp will not light when the switch is off.

If the owner does not want to do electrical work, as suggested by the described methods, then you can simply additionally screw in a regular incandescent lamp if there is a free socket in the chandelier. The disadvantages of this method is that it will shine when the LED lamp is turned off. This will change the blinking to constant. Another disadvantage is that the screwed-in light bulb will consume electricity at times when lighting is not required at all.

Errors when connecting electrical wiring to the switch

If the LED lamp continues to work even when it is turned off, and the person does not use the backlit switch, then the reason may be incorrect wiring: a zero was connected to the switch instead of a phase. In this case, when the circuit is opened, the zero is switched off, not the phase, as a result of which the wiring is energized. As a result, the lamp lights up when the switch is off. This situation must be corrected by connecting the wires correctly. Otherwise, during a scheduled replacement of the lighting fixture, even when everything is turned off, there will be a danger of receiving an electric shock, since the wiring will be live.

Whatever method of eliminating blinking you choose, compliance with safety regulations is mandatory, and error-free connection of the wiring to the switch is the key to normal operation of the device.

Often, from customer reviews, you can hear complaints that when you turn off the lights in the house, the LED lamp either begins to flicker or continues to burn very weakly. Troublesome eye blinking problem. But in connection with why the LED lamp burns dimly after turning off the light and how to get rid of it, you will learn from this article.

Switch light problem

The most common question is “Why do LED bulbs continue to light when the switch is off?” people are using illuminated switches indoors. A miniature neon light bulb (sometimes an LED) located inside the housing does not affect the operation of the lamp when the light source is an incandescent or halogen lamp. If you screw an LED light bulb into a lamp, it will often continue to burn dimly even after the voltage is removed.

The problem of dimming or flickering after turning off the light switch is also common with compact fluorescent light bulbs (CFLs). The essence of the problem and methods for solving it are similar to those with LED lamps.

Why this happens becomes clear if you carefully look at the diagrams for turning on a light bulb through an illuminated switch, given below. From the diagrams it follows that at load L1 after turning off the lighting there is still a small potential that penetrates through the circuit of the neon light bulb (Fig. 1) or LED (Fig. 2) HL1. In some cases, this is enough to start the LED lamp power circuit. As a result, the turned off LED lamp does not go out completely. It either glows faintly or glows at half-glow, or flickers spontaneously.

Designations on the diagrams:

• HL1 – LED or neon backlight;
• D1 – diode limiting reverse voltage;
• L1 – LED main lighting lamp;
• S1 – illuminated switch.

There are three ways to fix this problem:

Design feature of the LED lamp

The second most common reason why an LED lamp lights up dimly when the switch is off is hidden in its driver. And this is not surprising, because every manufacturer of LED products uses dozens of types of driver circuits, constantly changing and improving them. But often such changes are made with one goal - to reduce the cost of the finished product. But as a result, due to the use of low-quality components and errors made when assembling the driver, the LEDs remain lit even when the lights are turned off. Such a malfunction does not reduce the service life of the LED lamp, but it cannot be eliminated.

Poor quality wiring

Another common reason why LED lights light up when the switch is off is faulty wiring. You should seriously think about repairing it if:

• aluminum wires have been in use for more than 30 years;
• problems arise with LED lamps from different manufacturers;
• the switch that opens the circuit with the LED lamp does not have a built-in backlight.

Electrical wiring can affect the operation of an LED lamp in two cases:

1. The phase and zero are swapped, that is, the phase wire goes directly to the cartridge, and the zero wire goes directly to the switch. In this case, the LED spotlight driver or bulbs are constantly energized, causing the LEDs to either dim or flash despite the electrical circuit being open. The problem is solved by reconnecting the wires in the junction box so that the “phase” goes to the switch, and the “zero” goes to the lamp.
2. Another malfunction is a violation of the integrity of the hidden wiring, or rather the insulation of one of the wires. As a result, a small leak occurs inside the reinforced concrete wall, and the LED lamp continues to glow after the light is turned off. Using a megohmmeter, you can measure the insulation resistance and make sure that its value is underestimated. But it will not be possible to determine the location of the breakdown. Therefore, there is only one way out - to replace the section of wiring from the junction box to the chandelier.

Today it is common to replace conventional incandescent lamps with LED lamps; they consume electricity more economically and last longer. But it happens that when screwing a completely new light emitter into the socket, problems arise; the LED lamp glows when the switch is off. The glow is even, not flickering, but very weak. As soon as you replace the energy-saving light source with an old incandescent one, the problem disappears. This problem was voiced by the author of the review back in 2014.

There may be several reasons for this:

• resistor-based illuminator;
• problems in the power system;
• defective diodes;
• features of the power supply circuit;
• The switch is equipped with backlight.

After the appearance of such a phenomenon as a light burning when the switch is off, people immediately go to change the light fixture, thinking that it is defective. But this is only one of the reasons that may not be confirmed. The problem of smoldering light can become its advantage, acting as a night light in the dark. This is convenient for a toilet or corridor, but in a recreation area it can cause discomfort. Therefore, you should understand and find the source of the reason for the light glowing after the switch is turned off.

Effect of lamp structure

To understand why LED lamps light up when the lights are off, you need to look into its structure. The stores offer illuminators of different sizes and shapes. The internal structure is also different. Probably everyone has noticed large differences in the price category of this product, from 100 rubles to a thousand. It is the features of the device that determine such a wide range.

One of the main differences between modern lighting and conventional incandescent lighting is a constant supply of current; such circuits are called rectified. The LED lamp has the following components:

• glass diffuser;
• board with diodes attached to it;
• radiator;
• ballast with capacitor;
• base

The capacitor, which converts and stores energy, is located on the driver. Then the current is supplied through the circuit to the board, from it to the chips and diodes. A high quality LED lamp has a slightly different operating principle. The basis is a diode bridge; it supplies energy to the LEDs in a series connection. Such sources will not be disturbed by a dim glow after the switch is turned off.

Do not confuse an LED lamp with a fluorescent lamp. It is luminescent light emitters that are called energy-saving.

Most often, they can be distinguished by their spiral-shaped flasks. They gradually gain light when turned on, and there are no problems with the glow when the switch is off.

Fixing the glow problem

There are several ways to stop LED lamps from glowing when turned off, depending on the reason. If the switch has a backlight, it should be removed. This is the most common reason why lights stay on after being turned off. You can check why LED bulbs are lit when the switch is off in chandeliers with several sockets. Here one or all light emitters can smolder or blink.

The built-in diode closes the circuit, and a small part of the current passes, producing a glow. To troubleshoot problems, you need to pry and unlatch the switch key and remove the base. Then pull out the LED with its mount and install the entire structure back. Some switches do not have a large enough resistor, increasing it will solve the problem.

The second most popular reason for the glow when the switch is off is an LED lamp with a resistor. To glow, the current must be converted; this function is performed by a resistor. Energy can accumulate in it, gradually depleting the reserve after the power is turned off. Hence the result that the LED lamp is lit after switching off. In some cases, energy is released in bursts, charging and discharging. The problem is solved by purchasing another light emitter of better quality. You can also disassemble the illuminator and make a bypass with a capacitor, it costs a penny. But it’s unlikely that anyone will want to delve into electronics, unless it’s a matter of principle.

The LED lamp is of poor quality and stays on after switching off. Products with an affordable price may have external or internal defects. This is not a rule, but, nevertheless, it occurs. The problem with such affordable devices is incorrect soldering of the board. In this case, the LED backlight lights up after turning off due to design features, so you need to buy a higher quality light emitter.

Another common cause is incorrect wiring where the current flow does not stop. LED lights are sensitive, and they only need this small amount of voltage to maintain a dim glow when the switch is off. If the LED lamp lights up evenly, then there is enough current. It happens that the LED backlight lights up intermittently, lights up for a while and goes out. This means that there is little energy, but gradually it accumulates in the capacitor and splashes out onto the LEDs.

The wiring problem is the most difficult to solve. To do this, you need to find the source of the energy leak. There is a simpler option: installing an additional load so that there is less resistance. Here you can install an old incandescent light emitter, insert a relay, or an additional resistor into the circuit. The leaking energy will go to this load, and the LED lamp will not light up after turning off.

Effect of a burning light bulb after switching off

For those for whom a slight night glow does not cause discomfort, another question arises: is it safe? And how does this affect energy consumption? There is no danger in the smoldering light. The lamp will not burst in the middle of the night or crack. Burnout is possible, but it is an extremely rare case.

The main disadvantage of LED bulbs glowing when the switch is off is the rapid depletion of the illuminator. The fact is that the circuit is designed for a certain number of starts and burning times. Therefore, after two months of almost continuous glow, the light bulb becomes unusable.

To ensure that the problem of light decay does not bother you in the future, you need to choose the right lighting fixtures and switches. First of all, you should focus on well-known and trusted manufacturers. Pay attention to the proportionality of the power and the radiator of the light emitter. If the radiator is small, but the light output is quite powerful, then you should not buy one. Preference should be given to aluminum radiators. If the issue is not fundamental, then it is better to take the switch without backlight.

In the lighting equipment market, LED lamps are in greatest demand. This is due to their advantages over light sources with similar characteristics. Significant advantages are their efficiency, reduced pulsation coefficient, fire safety, and longer service life compared to other lamps. But along with them, LED lamps have some disadvantages. One of the disadvantages is the glow when the switch is off. If, when the switching device was turned on, the lamps burned evenly and without flickering, and when turned off, their light dimmed but remained, then this will be the situation described below.

When faced with this phenomenon, one should not be surprised. This indicates that current is flowing through the LED. There is also a positive side to this process. By installing an LED floodlight to illuminate the yard area, it can be used as a backlight at night. But there is also a negative scenario when the lamp starts to light up, but immediately goes out. This will obviously get on your nerves at night. Let's look at this phenomenon and look in detail at ways to eliminate it.

One of the reasons why an LED lamp burns after turning off may be:

1. poor insulation or other damage to electrical wiring;
2. Structurally, the LED lamp has low quality LEDs;
3. the switching device has a light indication;
4. unusual functioning of the LED.

If the switch keys are in the “off” position, and the lamps are still on, then you must first check positions 2, 3. Since it is difficult to identify the location of damage in the electrical wiring.

To find an area that has insufficient insulation, it is necessary to apply increased voltage to the circuit for 60 seconds. As a result, a breakdown occurs at the site of damage. The wiring section must be replaced.

But sometimes the LED glows faintly due to its special functionality. When current passes through a circuit, a capacitor is capable of storing electrical energy. And after stopping the voltage supply, it has a residual glow. And also, when the light is turned off, the lamp continues to burn dimly at full intensity due to its poor quality. In most cases, the error lies in the microcircuit.

What you need to pay attention to when buying an LED lamp

The main criterion for choosing an LED light source is the high quality of the LED itself. And it has a high cost, so good quality lamps cannot be cheap. Consider characteristics such as power and luminous flux. Try to buy lamps from reliable and trusted manufacturers; low-quality Chinese ones can quickly break.

If the lamp glows when the switch is off, then when purchasing in the future, take into account the overall dimensions of the radiator. The function of this part of the LED lamp is to cool it. Before purchasing a light source, pay attention to the presence of a radiator and matching lamp power.

Incorrect connection of switching device wires

Another common reason why an LED lamp lights up after being turned off is errors in switching the switch wires.

The electric current passing through the backlight recharges the capacitor device. When the required charge limit is reached, the operating circuit starts, accompanied by a short-term glow. Then the shutdown mode occurs. After some time, the situation repeats itself again.

The disadvantage of this mode is that any light bulb has a specific working resource. It is calculated by the number of switchings (on/off). After this resource is exhausted, the lamp will become inoperable. A similar problem occurs with low-power LED tape units, which have a current rectifier and a capacitor at the input. A small electric current passing through the switching device with light indication will allow the capacitor to recharge. Therefore, LED lamps may glow after switching off or flicker.

What to do if you installed a diode lamp, but it glows after being turned off?

Elimination methods

1. The simplest way to troubleshoot the problem is to disconnect the conductors that power the light indication. This wiring must be removed by first removing the cover of the switching device.

If you do this, there will be no current charging the capacitor and the light bulb will stop flickering when the switch is off.

1. To avoid such a problem, you should not purchase a switch with a light indication.
2. If you cannot do without such a switch, and you do not want to put up with the glow when it is off, then a parallel installed resistor will save the situation. Place it on the required part of the electrical circuit - and the current will flow along the path of least resistance here, and not through the driver. The price of this device is low, and you can purchase it at any radio equipment store.

The resistor will not negatively affect the operation of the LEDs. But it is necessary to take into account the fact that when the switching device is disconnected, the light indication will be on. The resistor will also draw electrical current, so don't forget to insulate it. Installing resistance yourself is a simple process. You need to remove the lampshade, and then connect the resistor contacts in the terminal block of the network conductors.

1. There is another way to eliminate the glow of the lamp. Install a light source with an incandescent filament (FI) in a chandelier with several sockets. The tungsten helix will act as a resistance when the switching device is turned off.

This method can quickly solve the problem in the short term. Please note that LN consumes 10 times more power than LED lamps, so you will need to take a closer look at the situation as soon as possible. Otherwise, the economic aspect of using LED lamps is lost.

16.06.2014

Please tell me, after turning off the switch, the lamps glow a little. How to fix this? I've already turned off the backlight LED in the switch - it doesn't help. Thank you.

This sometimes happens with switches equipped with LED backlights that light up when they are off. It is this glow that is usually the cause of smoldering or blinking of LED lamps when turned off - a small current that provides illumination of the switch causes smoldering in the lamps. We remove the backlight of the switch - we solve the problem, because... Now the power supply circuit is completely broken.

If you have already removed the backlight, but the problem remains, then the situation is more complicated, and there may be two reasons.

1) The problem is in the switch itself - the current escapes through it. Disassemble and try to physically disconnect the wire. If the glow goes away, simply replace the switch with a different model.

2) But if the smoldering remains, then it is obvious that the switch is connected completely incorrectly. Namely, it is hung on the wrong wire - it breaks the zero (ground), but should break the phase. It turns out that the phase is constantly supplied to the lamps, which leads to smoldering. Actually, if installed correctly, even in this case they should not smolder, but, apparently, the mass of your LED lamps or lamps is not insulated (which, of course, is not very good), and this mass is in contact with either the metal suspended ceiling or the supporting concrete designs. This can be corrected by swapping the current-carrying wires so that the switch breaks the phase. This is done either in the dashboard or in the transfer case.

You may also be advised to hang a simple filter on each lamp, which will absorb the current leakage. But we categorically do not recommend doing this - in this case you will have a constant current runaway.

We need to fix the wiring!