Why does an energy-saving light bulb stay on after the lights are turned off? Why do LED lamps burn when the lights are off? Review of causes of glow

16.10.2023

Many of us, in order to save energy, have long replaced traditional incandescent lamps with LED and fluorescent lamps. And everything would be fine if there were no “buts”. In some cases, it happens that energy-efficient light bulbs begin to blink or continue to glow faintly even when the switch is turned off, and this phenomenon is not observed with incandescent lamps in the same socket. What is the reason, and what should be done in this case to correct the situation?

The thing is that the design of an energy-saving lamp, LED or compact fluorescent, is distinguished by the presence in its base of an electronic ballast, which is powered by rectified mains voltage. The base contains a diode bridge, a smoothing capacitor, and a high-frequency voltage converter circuit that provides the correct power to ignite the LEDs or gas in the bulb.

The peculiarity of this ballast converter is that it starts exactly at the moment when the voltage level on the built-in filter capacitor becomes sufficient for this, that is, if for some reason the capacitor is sufficiently charged, the lamp immediately flashes.

Thus, the reason why an LED or compact fluorescent lamp continues to glow or blink when the switch is off is the current flowing into it, even a very small one.

Where does this small current come from? Often the problem described occurs when an illuminated switch is used. In addition to button-closing and opening contacts, such switches are additionally equipped with a chain consisting of an LED (or a small neon light bulb) with a resistor.

When the contacts of such a switch are open, the backlight circuit is turned on and is fed in series with the light source controlled by this switch.

The current there is tiny, and if an incandescent lamp is used, then it is not enough for the spiral to heat up even a little, but if a lamp with an electronic ballast, such as LED or fluorescent, is used, then this current is enough to charge the capacitor built into the lamp base, and then the lamp will blink from time to time or glow continuously if its power is not high.

Some conscientious manufacturers of LED and fluorescent lamps indicate on the packaging that this lamp should not be used in combination with a dimmer or backlit switch. But what to do if a problem does arise? There may be several ways out of this situation.

The first way to get rid of the disease is to remove the backlight circuit from the switch. Simply disassemble the switch and remove any interfering elements from it. Now you won’t have a backlit switch, but the light bulbs won’t light up unnecessarily. Or you can simply replace the switches with switches with a regular button without backlight in places where there are energy-saving light bulbs that light up by themselves.

The second method is to add shunt resistors in parallel to the circuits with problem light bulbs (a 2-3 watt 50 kOhm resistor will be enough) or simply add incandescent lamps in parallel so that the switch backlight current flows not through the ballast of the energy-saving light bulb, but through a circuit of lower resistance, then the ballast The energy-saving light bulb simply won't turn on until you press the switch. The shunt resistor can be conveniently installed in a junction box or under.

Due to their economical energy consumption, LED lamps are gradually replacing incandescent lamps. They are used in private houses, apartments, street lighting, illumination of shop windows and areas. Semiconductor-based devices provide a uniform light output without harmful pulsation and flicker. When using LED lamps, you may notice an unusual effect - glow after switching off. A dim lamp at night replaces the lighting and does not disturb the apartment residents. Electricity consumption for a weak glow is minimal. The downside of the glow is the depletion of the LED resource. Continuous operation leads to rapid burnout of the crystal.

Main causes of residual glow

If the LED lamp lights up after turning off, you need to check the wiring

Constantly smoldering or flickering light bulbs in the bedroom quickly become boring. Residents begin to look for the reason for the irritating behavior of the lamp. Electricians name several factors why an LED lamp burns dimly after being turned off:

use of a switch with LED backlight;
electrical wiring faults;
errors when connecting the lamp to power;
low quality LED lamps.

Once you have determined the source of the problem, you can fix it yourself or contact a professional electrician.

LED lamp device

Design of a standard LED lamp

The structural features of the diode lamp explain the effect of glowing or blinking at the moment of switching off. Main components of the LED device:

Glass diffuser or bulb - serves to evenly distribute the light flux.
A board with diodes is an aluminum base with conductive tracks and a group of LEDs that create a luminous flux. Applying a special paste improves heat removal from the chips.
Driver is a high-tech device for converting current characteristics.
A heatsink is a structure made of aluminum or its alloy to remove heat from the board.
Standard base made of brass with thread - the part does not differ in size and structure from the base of an incandescent lamp. This allows devices to be replaced using old cartridges. The base of the base part is made of polymer. Its function is protection against electric current.

The driver is an alternating current converter for a stationary network of 220 V. It uses resistors and capacitors as smoothing filters. To rectify the current, a diode bridge is installed. Household lamps use linear converters; high-power devices are equipped with pulse drivers.

The ability of capacitors to store and then release current explains why LED light bulbs remain dim for a while after the lights are turned off. Installation of the element is required, otherwise the lamp will blink. Its capacity is small, the current quickly runs out and the lamp goes out.

Illuminated switch

A backlit switch may cause the LED lamp to burn partially.

Switches with a luminous LED element make it easy to navigate in the dark. When using LED lamps, this convenient design causes them to partially burn. The device diagram explains why turning it off does not result in complete darkness. It contains a capacitor that accumulates voltage. The potential is spent not only for illumination. Part of it goes to the LED lamp. The voltage is not enough to fully start, so the combustion is dim.

The glow can be constant or periodic. In the first case, the device will continue to glow evenly, using part of the potential. In the second option, the light will light up periodically. These differences are explained by the magnitude of the current flowing. The capacitor needs time to charge, the light flashes, and a faint light appears only when the charge accumulates. This mode negatively affects the service life; the lighting device wastes its allotted resource.

Electrical wiring faults

Faulty electrical wiring in the apartment

Electrical wiring problems are the most dangerous type of malfunction. It not only damages the LED fixture, but may cause a short circuit or electric shock. Malfunctions are caused by the following factors:

operation of wires for more than 15 years;
use of aluminum cables;
load exceeding the design capacity of the wiring.

There is a break in the wire insulation through which current flows out. A small amount of interference is enough to dim the lamp. In apartments, communications are usually laid in a hidden way, so finding the damaged area requires effort.

Incorrect installation of the lamp

When installing a lamp with your own hands, incorrect wiring often occurs. In the distribution box, the phase from the panel is directly connected to the lighting fixture, and the zero is sent to the switch. When the device is opened, current does not stop flowing to the LEDs. The main danger of the situation is the voltage on the lamp after switching off. A person touching the device will receive an electric shock.

Work to correct wire switching is carried out after a power outage.

Low quality light bulb

Low quality Chinese lamp

LED devices are installed to replace standard incandescent lamps to reduce electricity costs. They are safer than fluorescent energy-saving lamps containing mercury vapor. The main disadvantage of LED lighting is its high cost. The desire of manufacturers to save on parts leads to the appearance on the shelves of affordable, but low-quality products. In half the cases where LED lamps glow when the switch is off, the manufacturers are to blame.

Products of unknown manufacture have several main disadvantages: the lack of a driver, the use of a low-quality rectifier that causes pulsation. Instead of the driver, a power supply made of capacitors is installed. It cannot provide stable output current parameters. In addition, the power and color rendering index are overestimated. There is no warranty for such a product. In order not to look for the causes of the malfunction, it is better to immediately purchase products from trusted brands.

Solutions to the problem

The lamp may not turn off completely for months. At this time, the crystal ages, its brightness decreases, and its resource is exhausted. Having figured out why the LED bulbs light up dimly after turning off the lights, you can try to fix the problem yourself. This will require basic knowledge of electrical engineering and the ability to use tools. If you lack the skills, it is better to call an electrician.

What to do with the backlight of the switch

Shunt resistor

If the lamp cannot be turned off completely due to the LED light switch, the first tip is to replace the device. A model without additional functions will not cause a glow. The device with the LED element is installed in another place where it will not create difficulties. Another way out is to remove the backlight. The switch body is unscrewed, the wire to the chip is cut with a tool. Before starting electrical installation work, turn off the power supply to the panel.

If an LED is needed, look for a design solution.

Replace one of the LED fixtures in the lamp with an incandescent lamp. She will take away the free current. This method is only suitable for devices with several horns. The disadvantage of this method is that the energy-saving effect of lighting is reduced.
A more labor-intensive option is to install a resistor in parallel with the lamp in the circuit. Its resistance should be up to 50 kOhm. The current will go to the resistor, the capacitor will remain without charge. The radio component is purchased at a specialized store. When installing the legs, the parts are fixed to a terminal with wires.

Troubleshooting wiring

The problem with the wiring is solved by replacing the section with poor insulation. To find the damaged area, you will need a special device - a multimeter. When cables are installed openly, it is not difficult to find damaged insulation. Hidden placement of wires will require dismantling the decorative coating or plaster. Depending on the state of communications, a separate section or the entire wire is replaced. After installation, the grooves are sealed with gypsum mortar.

Incorrect connection of wires in the junction box is one of the reasons for the light bulb to glow. The correct switching order is: phase - to the switch, zero - to the light bulb. If the current goes directly to the cartridge, the device will not turn off. Transferring the phase to the switch will solve the problem.

How to choose the right LED devices

Energy-saving lamps

Poor quality lighting fixtures are a common reason why an LED light bulb stays on when the switch is off. There are several rules that will help you choose a reliable LED device.

At the very beginning of the 21st century, fluorescent or, as they are also called, energy-saving lamps in a compact arc-shaped or spiral design appeared on store shelves in our country. Some acquired these lamps a little earlier, having the opportunity to be on business trips abroad or vacations in European countries, some a little later. But everyone who purchased them bought them for one single purpose - to save on electricity. And this really worked out and bills came in for noticeably smaller amounts, accordingly the demand for these lamps grew and over time the assortment expanded to satisfy the most demanding consumer, but...

Technologies do not stand still and as one technology develops, another begins to develop, and sometimes it happens that these technologies come into conflict with each other.

With the development of energy-saving lamps, the range of switches has also developed; now there are quite a lot of them. These include one, two or three keypads, backlit, dimmer switches, pass-through switches and the like.

In our case, we will talk about backlit switches, because... They are very widespread and in many apartments they are already installed or are planned to be installed.

When installing a backlit switch, you need to keep in mind that installed LED or fluorescent lamps that will be powered by this switch will conflict with it. This conflict is expressed by the fact that when the switch is turned off, the lamp will light or, in the case of fluorescent lamps, blink, Therefore, you need to make a decision about whether you really need an illuminated switch or not. Just a couple of years ago, most electricians did not even know about this problem.

This happens because when the switch is in the off position, the electrical circuit does not completely open due to the backlight powered through a resistance. Since the circuit is not open, a small voltage is supplied to the lamp, and this voltage is enough to light the lamp at about 5% power. That is, when turned off, the lamp will operate in night light mode. In cases with fluorescent lamps, the lamp flickers subtly at different frequencies. Here the situation is such that the capacitors that are installed in the lamp soft starter accumulate the energy coming from the open switch and, when the full capacity is reached, this energy splashes out, which visually looks like blinking. In both cases, the service life of the lamp is not reduced. There are also times when everything works perfectly and nothing lights up or blinks anywhere. And it happens that, for example, everything works fine for a year, and then it starts to flash and light up. It all depends on the resistance in the switch and in the internal component of the lamp.

Ways to solve the problem

If you have already installed backlit switches and bought expensive LED lamps and were disappointed in advance that they could have sold you a defective product, know that this is not the case. The problem can be solved in several ways, which our specialists have tested in practice:

If you have a multi-arm chandelier, then you can remove the blinking or backlighting effect by installing the lowest-power incandescent lamp in one of the arms. It will collect all the current passed through the backlight. This can also be applied if you have ceiling lights installed. Even if you have one horn for one lamp in the room, the problem can be solved with the help of an adapter from one socket to two;

Directly in the switch, use wire cutters to cut through the resistance of the power supply to the switch illumination. That is, turn a backlit switch into a switch without backlight. Of course, this method can be used only by de-energizing everything in advance;

Replace the resistance in the switch with a resistance with a higher ohm. In this case, detailed consultation with an electrician and, accordingly, his participation in the replacement are required.

So if you bought LED lamps, and they glow when turned off, know that the solution to this problem is not so difficult and, in the first two cases, not very expensive.

LED lamps are well-deservedly popular for many reasons. LED light sources are characterized by long service life, economical power consumption and reliability. However, in addition to the advantages, LED bulbs also have disadvantages. The most common problem consumers encounter is when the LED lamp glows when the switch is off.

Features of LED lamps

LED bulbs have a slightly more complex internal structure compared to conventional incandescent bulbs.

Main elements of an LED lamp:

Nickel-plated brass base. These materials avoid corrosion processes and also ensure good contact with the cartridge.
The base of the plinth is made of polymer (polyethylene terephthalate). The material protects the device body from electricity.
The driver is based on a galvanically isolated current stabilizer modulator circuit. The driver's task is to create conditions for stable operation of the light source even in the event of power surges.
The radiator is made of anodized aluminum alloy. The coating allows heat to be removed from those surfaces of the lamp that are not allowed to overheat.
Aluminum printed circuit board. The component guarantees the desired temperature regime for the chips by dissipating heat to the radiator.
Chips. They represent a key element of the system. They are also called diodes.
Diffuser. It is a glass hemisphere with the highest level of light dispersion achievable within the technology.

The operating principle of LED lamps is based on the release of photons. This occurs as a result of permanent change and the appearance of multiple combinations of electrons. Uninterrupted changes are ensured by the presence of conductors. To optimize the process, resistors or current limiting devices are used.

Recently, more advanced systems have appeared that provide high consumer performance. These bulbs use diode bridges. However, the prices for such lamps are much higher than for old-style products.

Why does the LED lamp glow when the switch is off?

There are several common reasons why LED bulbs glow when the switch is off:

Low quality insulating materials.
Using an illuminated switch.
Low quality light bulb.
Problems with electrical wiring.
Features of the power supply circuit.

Poor quality insulation

Insufficient quality insulation in any part of the electrical circuit often causes problems with light. This malfunction has the most serious consequences, because to correct it you will need to disturb the finishing layer on the walls in order to replace the insulation.

To check the insulation for current leakage, apply high voltage to the network for 1 minute. This is necessary to simulate the conditions under which breakdowns occur in the electrical circuit.

Using Illuminated Switches

The answer to the question of why an LED lamp glows when the switch is off lies in the use of an illuminated switch. The inside of such a device contains a light diode with a current-limiting resistor. The reason the lamp glows is that even when the contact is disconnected, voltage still passes through them. However, the light bulb does not glow at full power, since the circuit contains a current-limiting resistor.

The lamp shines either constantly (if the current is sufficient) or intermittently (flashes because the current is too weak). However, even in the latter case, the current is sufficient to recharge the capacitor. As soon as sufficient voltage accumulates in the capacitor, the stabilizer chip turns on, and the light bulb immediately lights up. Operating the lamp in this mode leads to its rapid wear, since the number of operation cycles for microcircuits is finite.

In this case, there are several methods to eliminate the problem of the luminous light bulb. The easiest way is to remove the backlight from the switch. To do this, dismantle the housing and remove the wire directed to the resistor or light diode. It is also possible to replace the switch with another one that does not have a backlight function.

Another way to solve the problem involves soldering a shunt resistor parallel to the light bulb. You will need a 2 watt resistor with a resistance of up to 50 kOhm. If you do this, the current will flow through this resistor, and not through the light bulb power driver. Installing the resistor is not difficult. You just need to remove the lampshade and secure the resistance legs in the terminal block for connecting the network conductors.

It is enough to connect one resistor to the switch, there is no need to hang them on each lamp.

If you do not have sufficient knowledge of electrical engineering, you can do something simpler. To do this, place a regular incandescent lamp in the lighting fixture. The spiral of the light bulb will serve as a shunt resistor when turned off. However, this option is only suitable if there are several cartridges in the lighting fixture.

Low quality light bulb

Often the cause of a malfunction is an insufficiently high-quality lamp. In this case, there is only one way to solve the problem - replacing the product with a better one.

Electrical wiring problems

If errors are made during the installation of electrical wiring, one of the consequences of this may be the lamp glowing when the switch is already turned off. This situation happens when the zero is confused with the phase, and even after disconnecting the wires remain under the phase.

The situation should be corrected not only to get rid of the unnecessarily shining light bulb. This is also to avoid electric shock when replacing the lamp.

Features of the power supply circuit

To provide a brighter glow and reduce light ripple, a high-capacitance capacitor is sometimes added to the power supply circuit. This results in the fact that even when the switch is turned off, there is still enough charge in it to allow the LEDs to glow.

Carefully read the instructions that come with the LED lamps. It specifies the rules for using the product.
Some convenient lighting features are not easily compatible with LED bulbs. Timers, light intensity controllers, photovoltaic elements, and backlighting often cause failures in the normal operation of LEDs.
Pay attention to the dimensions of the radiator. This element is responsible for removing a sufficient amount of thermal energy that is released when the light is on. The dimensions of the radiator and the power of the lamp must be consistent with each other.
Radiator material. The best choice is an aluminum radiator. Ceramic and graphite products have proven themselves to be excellent.
The quality of the joint between the light bulb body and the base. If there are obvious mechanical defects at the junction, the likelihood of problems with the lamp glowing when the switch is off increases. The base must be securely fixed to the body without play.
Ripple level. The correct glow is uniform, without any flicker. However, it is quite difficult to notice irregularities in the light. This is where a mobile phone video camera comes in handy - it makes it much easier to spot flickering.

Features of LED lamps

LED bulbs have a slightly more complex internal structure compared to conventional incandescent bulbs.

Main elements of an LED lamp:

Nickel-plated brass base. These materials avoid corrosion processes and also ensure good contact with the cartridge.
The base of the plinth is made of polymer (polyethylene terephthalate). The material protects the device body from electricity.

The driver is based on a galvanically isolated current stabilizer modulator circuit. The driver's task is to create conditions for stable operation of the light source even in the event of power surges.
The radiator is made of anodized aluminum alloy. The coating allows heat to be removed from those surfaces of the lamp that are not allowed to overheat.
Aluminum printed circuit board. The component guarantees the desired temperature regime for the chips by dissipating heat to the radiator.
Chips. They represent a key element of the system. They are also called diodes.
Diffuser. It is a glass hemisphere with the highest level of light dispersion achievable within the technology.

Recently, more advanced systems have appeared that provide high consumer performance. These bulbs use diode bridges. However, the prices for such lamps are much higher than for old-style products.

Why does the LED lamp light up when the switch is off?

There are several common reasons why LED bulbs glow when the switch is off:

Low quality insulating materials.
Using an illuminated switch.
Low quality light bulb.
Problems with electrical wiring.
Features of the power supply circuit.

Poor quality insulation

To check the insulation for current leakage, apply high voltage to the network for 1 minute. This is necessary to simulate the conditions under which breakdowns occur in the electrical circuit.

Using Illuminated Switches

The lamp lights either constantly (if the current is sufficient) or intermittently (flashes because the current is too weak). However, even in the latter case, the current is sufficient to recharge the capacitor. As soon as sufficient voltage accumulates in the capacitor, the stabilizer chip turns on, and the light bulb immediately lights up. Operating the lamp in this mode leads to its rapid wear, since the number of operation cycles for microcircuits is finite.

In this case, there are several methods to eliminate the problem of a burning light bulb. The easiest way is to remove the backlight from the switch. To do this, dismantle the housing and remove the wire directed to the resistor or light diode. It is also possible to replace the switch with another one that does not have a backlight function.

It is enough to connect one resistor to the switch, there is no need to hang them on each lamp.

Low quality light bulb

Often the cause of a malfunction is an insufficiently high-quality lamp. In this case, there is only one way to solve the problem - replacing the product with a better one.

Electrical wiring problems

The situation should be corrected not only to get rid of the unnecessarily burning light bulb. This is also to avoid electric shock when replacing the lamp.

Features of the power supply circuit

Carefully read the instructions that come with the LED lamps. It specifies the rules for using the product.
Some convenient lighting features are not easily compatible with LED bulbs. Timers, light intensity controllers, photovoltaic elements, and backlighting often cause failures in the normal operation of LEDs.

Pay attention to the dimensions of the radiator. This element is responsible for removing a sufficient amount of thermal energy that is released when the light is on. The dimensions of the radiator and the power of the lamp must be consistent with each other.
Radiator material. The best choice is an aluminum radiator. Ceramic and graphite products have proven themselves to be excellent.
The quality of the joint between the light bulb body and the base. If there are obvious mechanical defects at the junction, the likelihood of problems with the lamp glowing when the switch is off increases. The base must be securely fixed to the body without play.
Ripple level. The correct glow is uniform, without any flicker. However, it is quite difficult to notice irregularities in the light. This is where a mobile phone video camera comes in handy - it makes it much easier to spot flickering.

220.guru

Review of causes of glow

What to do if the LED lamp is on? There are several reasons why, after turning off the lighting device, the LED lamp continues to burn, even dimly or weakly:

Is this glow dangerous? This problem does not pose any danger to the wiring, but the service life of LED bulbs will be noticeably reduced if they constantly flicker or glow dimly.

If the switching device is in the off position, and the emitter still glows and burns, then it is best to check the last three factors first. This is explained by the fact that it is very difficult to find weak insulation areas in electrical wiring.

In order to do this, it is necessary to create special conditions, as a result of which a high voltage is applied to the circuit for one minute to cause a breakdown. The section of the circuit that causes the lighting element to glow after the switch is turned off will need to be opened. Moreover, if the electrical wiring was installed in a hidden way, then opening it will lead to damage to the integrity of the wall.

It is important to know! There are many situations where when LED light sources are connected to a backlit switch, they function differently. This occurs due to the fact that the lighting element, which is installed in the switching device, closes the circuit and, accordingly, passes a small current. This is what charges and allows the light bulb to glow when the switch is off.

Another problem why an LED lamp glows in the dark is the low cost of the product. If you purchased a poor quality LED light bulb, this can also lead to a similar phenomenon. This is due to the fact that there is some kind of error in the board. But it also happens that the emitter burns dimly due to the fact that it has its own peculiarity in the functioning of the structure.

We are talking about the processes that occur in capacitors when a load is applied to the lighting element. When electric current passes through the circuit, the capacitor stores energy, and then after the load is stopped, it continues to keep the elements glowing.

Another fairly common reason why LED lamps glow when the switch is off is incorrect connection. You can learn more about this from the video:

samelectrik.ru

Device Features

The design of this type of lamp is more complex than its analogue with an incandescent filament. Main elements: base (screw, pin), board with emitters, diffuser, driver. The principle of operation is based on the recombination of electrons and holes with transfer to another energy level, resulting in a glow that is a consequence of the release of photons. These processes are facilitated by the use of certain LED semiconductor materials.

To ensure acceptable lamp operating conditions, a current-limiting element is used. In simpler circuits, a resistor is used for this purpose.

Higher quality light sources operate on a different principle: the circuit is based on a diode bridge, which rectifies the mains voltage and supplies it to LEDs connected in series.

Lamp glow when the load is off

There are several likely factors that could explain why the lighting element is still lit after being disconnected from the power source, albeit dimly:

Problems with electrical wiring, in particular, poor-quality insulation on one of the sections of the circuit.
The LED lamp is connected to a backlit switch.
Poor quality emitters used in the design of the light source.
Functional features of the lamp.

If the emitters burn when the switching device is in the off position, it is recommended to first consider all other factors except the first, since it is problematic to determine the area of hidden wiring that is weak in insulation.

To do this, conditions are created under which a circuit breakdown occurs (high voltage is applied for 1 minute). The problem area, due to which the diode lamps glow after the load is turned off, will have to be opened: the integrity of the wall is compromised if the wiring is laid using the gating method.

A very common situation occurs when energy-saving light sources function differently when connected to a backlit switching device. The problem here lies in the fact that the lighting element installed in the switch completes the circuit, which means it passes a small current. It powers the diode lamps when the lights are off.

The problem of cheap LED products is no less common. If a product of low quality at an affordable price was chosen, and usually the connection between these factors is direct, then there is a high probability of an error in the soldering board. But it happens that the emitter, although dimly, burns due to the functional features of the design.

In particular, we are talking about the processes that occur in the resistor when a load is applied to the lamp: this element accumulates energy as current flows through the circuit, and after the load is turned off, it maintains the glow in the emitters.

How to solve the problem of dim light

If you initially purchased a cheap LED lamp, then it is possible to eliminate the glow only by installing a product from a reliable manufacturer and of high quality.
When the problem lies in the backlit switch, it can be eliminated in different ways. The simplest solution is to change the switching device to a model without backlight. You can also cut off the corresponding backlight power wire; this is done after opening the switch. But in some cases it is important to preserve this function. Then you need to install a resistor in parallel on the desired section of the circuit.
The hardest problem to fix is the one in the wiring. To do everything correctly, of course, it is recommended to find the source of the leakage current. But, as already mentioned, this will entail other difficulties. But as a result, when the light is turned off, the diode lamps will not light up. But you can go another way, a simpler one. To do this, a load (incandescent lamp, resistor or relay) is connected in parallel with the diodes that light up. It is important that the resistance of this element is less than that of LED emitters. As a result, the leakage current will flow, for example, to an incandescent lamp. But due to the slight resistance it will not burn.

As you can see, there are many ways to solve the problem of diode-based emitters, which, although dim, still shine when turned off. It is necessary, if possible, to determine the most likely cause of this phenomenon.

The main advice is to pay attention to lighting products from reliable and trusted manufacturers. It is important to remember that high-quality diode light sources cannot be cheap. This will avoid a number of problems, the most common of which are dim light when the load is off and short service life.

Effective lighting, among other things, is also based on the compliance of the basic parameters of the light bulb with the conditions in which it will work. When choosing, the power of the product, luminous flux, color temperature, color rendering index, and luminous angle are taken into account.

If the light source lights up when the load is off due to rather poor quality, then when choosing a new product, its dimensions should be taken into account. In particular, we are talking about the size of the radiator.

This is an auxiliary design element that facilitates more efficient heat removal from the light source. Before purchasing, you need to pay attention to the correspondence between the dimensions of the radiator and the power of the lamp. If the product is characterized by a small cooler with significant power, then this design option is not worth taking.

The most reliable radiators are made of graphite, ceramics, and aluminum. Moreover, it is important that this element is not type-set.

You also need to pay attention to the quality of the connection between the base and the lamp body. It is important that there are no nicks along the edge of the holder and, in general, it should be characterized by a complete absence of play. Another key point is the level of light pulsation. High-quality lighting elements emit a uniform glow.

The difficulty of checking a lamp for light quality is that the pulsations are invisible to the eye. But craftsmen have come up with a way to solve this problem: you need to use the turned on camera of a mobile phone or camera. The pulsations will be visible because the image will begin to blink.

Thus, if the lighting system immediately after installation produces a weak glow from diode-based lamps, it is recommended to check the circuit, switch and other factors. The fact is that when, with the load turned off, the lighting elements still light up, albeit dimly, this may indicate problems with the wiring, which is already quite serious. To accurately determine the cause, all possible factors must be considered.

proosveschenie.ru

The most common reason for a lamp to glow after being turned off is backlit switches.

Inside such a switch there is an LED with a current-limiting resistor. The LED lamp glows dimly when the light is turned off, because even when the main contact is turned off, voltage continues to flow through them.

Why does an LED lamp burn at full heat and not at full power?? Thanks to the limiting resistor, the current flowing through the electrical circuit is extremely insignificant and insufficient to light an incandescent electric lamp or ignite fluorescent lamps.

The power consumption of LEDs is tens of times lower than the same parameters of an ordinary incandescent lamp. But even a small current flowing through the backlight diode is sufficient for the LEDs in the lamp to glow weakly.

There can be two lighting options. Either the LED lamp lights up continuously after turning off, which means that sufficient current flows through the LED backlight of the switch, or the light flashes periodically. This usually happens if the current flowing through the circuit is too small to cause a constant glow, but it recharges the smoothing capacitor in the power supply circuit.

When sufficient voltage gradually accumulates on the capacitor, the stabilizer chip is triggered and the lamp flashes for a moment. Such blinking must be definitely combated, no matter where the lamp is located.

In this operating mode, the lifespan of the power board components will be significantly reduced, since even the microcircuit does not have an infinite number of operation cycles.

There are several ways to eliminate the situation when the LED light is on when the switch is off.

The simplest is to remove it from the backlight switch. To do this, we disassemble the housing and unscrew or bite off with wire cutters the wire going to the resistor and LED. You can replace the switch with another one, but without such a useful function.

Another option would be to solder a shunt resistor in parallel with the lamp. According to the parameters, it should be designed for 2-4 W and have a resistance of no more than 50 kOhm. Then the current will flow through it, and not through the power driver of the lamp itself.

You can purchase such a resistor at any radio store. Installing the resistor is not difficult. It is enough to remove the lampshade and fix the resistance legs in the terminal block for connecting the network wires.

If you are not particularly friendly with electricians and are afraid to “interfere” with the wiring yourself, another way to “fight” backlit switches can be to install a regular incandescent lamp in the chandelier. When turned off, its spiral will act as a shunt resistor. But this method is only possible if the chandelier has several sockets.

Problems with electrical wiring

Why does the LED lamp glow after being turned off even if the backlit button is not used?

Perhaps, when installing the electrical wiring, an error was initially made and zero is supplied to the switch instead of a phase, then after the switch is turned off, the wiring still remains “under phase”.

This current situation must be eliminated immediately, since even with a scheduled replacement of the lamp, you can receive a sensitive electric shock. Any minimal contact with ground in this situation will cause the LEDs to glow dimly.

Features of the power supply

To increase the brightness of the glow and minimize lighting ripple, high-capacity capacitors can be installed in the power driver circuit. Even when the power is turned off, there is enough charge left in it to light up the LEDs, but it only lasts for just a few seconds.

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At the very beginning of the 21st century, fluorescent or, as they are also called, energy-saving lamps in a compact arc-shaped or spiral design appeared on store shelves in our country. Some acquired these lamps a little earlier, having the opportunity to be on business trips abroad or vacations in European countries, some a little later. But everyone who purchased them bought them for one sole purpose - to save on electricity. And this really worked out and bills came in for noticeably smaller amounts, accordingly the demand for these lamps grew and over time the assortment expanded to satisfy the most demanding consumer, but...

Technologies do not stand still and as one technology develops, another begins to develop, and sometimes it happens that these technologies come into conflict with each other.

In our case, we will talk about backlit switches, because... They are very widespread and in many apartments they are already installed or are planned to be installed.

Ways to solve the problem

So if you bought LED lamps, and they glow when turned off, know that the solution to this problem is not so difficult and, in the first two cases, not very expensive.

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How does LED light work?

The design of an LED lamp is never the same, since each individual manufacturer provides a different layout and circuit for creating the device. However, the general effect of the device remains the same. The required components of LED lamps are: base, driver, radiator, board with sources emitting light and bulb.

When voltage is connected to the light bulb, a chaotic movement of electrons occurs, which, colliding with each other, form holes, as a result of which a bright glow occurs. Thus, even if the minimum amount of current penetrates the semiconductor, it will glow or blink when turned off, so it is advisable to understand the reasons for this.

What causes LED bulbs to flicker?

Let's consider a number of factors that cause the LED device to glow when turned off:

incorrect connection of electrical wiring or lack of performance in certain areas;
poor quality of the device, incorrectly created lamp circuit;
Illuminated switch. Such a device becomes the most obvious cause of LED blinking;
if it is street lighting, it is often motion sensors and timers that influence;
Incorrectly selected voltage for lamps.

Attention! If the LED lamp is connected to a backlit switch, the backlight must be turned off. In this case, the network will open and the current will stop flowing to the capacitor.

The design of energy-saving lamps and the reasons for their flickering

Why does an energy-saving lamp flicker after being turned off is a trivial, but rather painful question. This scares some people, others simply try not to pay attention to the device so as not to worry.

A fluorescent lamp, similar to an LED source, operates from a small amount of direct current. The rectifier, which reduces the voltage for the lamp, is located directly inside the structure. There is also a capacitor, which is the reason the light bulb lights up regularly even when the switch is off.

Please note the backlit dimmer. If you are installing energy-saving appliances, there should not be such a switch. Otherwise, you can penetrate the light source mechanism and turn off the backlight. Then current pulses will stop penetrating into the capacitor.

Advice! Be sure to exclude all causes that cause pulsation of LED lamps and energy-saving ones, since after two to three months such lighting will need to be replaced due to the exhausted number of starts.

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What is this

A light emitting diode (LED) is a regular lamp that consists of many semiconductor crystals and an optical system. This is a semiconductor device that converts electrical voltage into lighting. The spectrum of emitted light depends on the chemical composition of the semiconductor. The first such device appeared in 1968 and was very expensive, and mass production of lamps was launched only in the 21st century. Their design resembles a mini-computer and includes a case, LED, diffuser, radiator, driver, and base. If the LED lamp glows when the switch is off, do not panic. There are several logical explanations for this phenomenon.

Peculiarities

Why does the LED lamp light up when the switch is off? It should be noted that the LED bulb is economical. It reduces electricity costs by almost six times. Long service life is one of the features of the device: the lamp retains its ability to illuminate for fifty thousand hours. It turns on immediately, without delay, like regular incandescent lamps. The LED does not contain hazardous elements, such as mercury and other heavy metals, which would have a negative impact on human health. In addition, the device practically does not heat up during operation, since it does not emit heat. White light does not irritate the human eye, even so bright.

pros

What should I do if the LED lamp glows when the switch is off? This is not dangerous? The mysterious afterglow does not pose a danger to humans. LED devices have many advantages:

Compared to conventional lighting, they consume a small amount of energy (10 volts) to evenly illuminate even a large room;
do not emit ultraviolet light and do not damage human eye tissue;
do not heat the air;
long service life allows for significant savings (if the light bulb shines for five hours every day, it will last for ten years);
environmentally friendly compared to energy-saving devices;
their body is durable, protected from strong impacts and damage;
weigh little;
warms up in one second.

One of the reasons why an LED lamp glows when the switch is off is because there is such a function in the switch.

Minuses

If the LED light glows when the light switch is off, there may be a problem with the wiring. Despite their innovation, functionality and technical characteristics, such lamps still have disadvantages:

the main disadvantage is the high price of the device compared to energy-saving and incandescent lamps;
many users are annoyed by the light spectrum of LEDs; they are not used for reading books or hard work;
Due to the massive use of LED lighting, electricity prices may rise.

These small disadvantages do not cover the significant advantages, which include energy savings, quality and safety.

Causes

What should I do if the LED lamp glows when the switch is off? "RadioKot" is a forum dedicated to electronics, contains a lot of useful information on this topic. According to forum members, there may be several reasons for the weak light after switching off.

Incorrect electrical wiring connection.
The switch has neon lighting.
The LED lamp turned out to be of poor quality.
The LED lamp has additional options (slowly extinguishing lamp).

LED lamps are designed in such a way that their main job is constant voltage. There is a rectifier inside the device, which receives current. Sometimes it happens that after turning off the lamp burns dimly or flickers. Problems with wiring and poor quality of LEDs used are the main reasons for this phenomenon. If the device uses a resistor, it keeps the diodes glowing. Electricity accumulates in them, so even after turning off the lamps emit a weak light.

This happens when the backlit switch is open. In this case, the current to the lamp comes from the switch itself. It does not affect the network load. The current performs the function of charging the capacitor. When charging reaches a certain level, it flashes and turns off. Thus, the process proceeds in a circle, and short blinks occur in the lamp or LED strips.

If you don't want to experience flickering lights during or after a shutdown, choose the right lamp. Conscientious manufacturers always indicate instructions on the packaging, which indicate the operating principle of LED lighting devices and recommendations for correct operation. It is not advisable to use LED lamps together with backlit key switches, photocells, brightness controls, and timers. All this interferes with the operation of the product and causes periodic blinking.

Unfortunately, lighting fixtures are often counterfeited. When purchasing, try to carefully study the packaging in which the lamp is located. The cause of burning after switching off, as well as blinking, is sometimes due to incorrect installation. If this problem bothers you, try to fix it yourself. Check that the light bulb is screwed in securely (with the power off). Remember that the simultaneous use of switches with neon lights (they are needed to recognize their location) and LEDs is not recommended.

Environmental friendliness

Are LEDs safe or not? Many people believe that these lamps are dangerous to human health. If we compare them with energy-saving ones, which contain mercury, we can say with confidence: LED lighting is the future. They are not only economical, but also environmentally friendly. The lamps protect the environment because they do not emit heavy metals after disposal. Their design is such that the devices operate without dangerous, harmful, toxic substances in their composition. Why does the LED lamp light up when the switch is turned off on the car? The cause may be incorrect wiring connections or an incorrectly selected light bulb.

Dangerous or not

Why does the LED lamp light up when the switch is off? There are different reasons, one of which is a malfunction of the device or its poor quality. If we compare LED lamps and traditional ones (fluorescent, mercury, metal halide, sodium) - the first are completely safe. Traditional modern lighting devices contain up to 100 mg of mercury vapor. If they are damaged during transportation or after they have served their useful life, toxic substances are released into the atmosphere. Mercury is dangerous not only for the environment, but also for humans in any of its states - liquid or gaseous.

Exploitation

Does the LED lamp glow when the switch is off? It is recommended to replace the device with a new one if there are no problems with the electrical wiring. Try not to neglect the rules for using LED lamps, then they will work properly.

Dismantling and installation of the device is carried out with the electricity turned off.
Do not allow the LED lamp to come into contact with water.
It is not recommended to use a lamp for street lighting unless it is protected from water and dust.
Lamps cannot be used in devices with a brightness control.
If the LED is used in a circuit with a switch that has a neon backlight, the light will glow faintly when turned off.
Connecting the lamp to a voltage different from the rated voltage leads to a reduction in service life.
Temperature changes in the operation of the lamp lead to its failure.
LEDs do not need to be recycled as they contain no hazardous substances.
The lamps are guaranteed for three years from the date of purchase.

LED lighting can completely replace traditional lighting. Such light bulbs are used in any lighting fixtures and interiors, depending on a person’s preferences.

Price

In the course of the article, we found out why the LED lamp glows when the switch is off. But whether to use it or not is up to everyone to decide for themselves. The objective disadvantage of LEDs is their high cost. The average price for lamps is two hundred rubles. The cost depends on the design of the device, its size and manufacturer. Over time, LEDs will become more accessible to the public.