Many people have a question: “What does an LED lamp consist of and how does it work?” In today’s article we will find out for you and also tell you why it is important to use only high-quality components when assembling a lamp.

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Features of LED lighting operation

If you are faced with the problem that the LED lamp is on when the switch is off, do not be surprised. This indicates that current is flowing through the LEDs. The brightness of the glow depends only on its strength.

On the one hand, this phenomenon has a positive side, if the lighting is in the toilet or corridor it can be used as night lighting. What if it's in the bedroom? It is possible that the light does not smolder, but flashes periodically.

There may be several reasons for this phenomenon:

• Use of illuminated switches;
• electrical wiring faults;
• features of the power supply scheme.

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 a 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.

I have a bad feeling that the article and the first comments were “ordered”. I am an expert in this field, so I can judge. I can advise you by e-mail if you want.

RUB 5,500 minimum for an Armstrong lamp? Pfff... Lies. Where do these prices come from? There is only one option - I looked at leading Western manufacturers. Despite the fact that high-quality lamps made in Russia (based on diodes from Cree, OSRAM, NICHIA, LG and other excellent manufacturers) cost twice cheaper. For 2,500 rub. I will find you an analogue of the standard one new raster lamp (new, because with degradation the raster lamp will lose 30-50% of lumens). For 5,000 rub. - the same "Armstrong", but twice as powerful.

About the other disadvantages: 100% true for consumer Chinese lamps or for lamps assembled in a garage in the backyard.

#9 maniak is absolutely right - the lamps in the pictures are of poor quality. If you see these, pass by. I will say more, you don’t even have to look for high-quality LED lamps for a standard base of standard sizes. The reason is simple - you cannot fit a high-quality driver and a powerful cooling system into a standard form factor.

Although lamps for suspended ceilings are very, very good. Thanks to the power of only 5-8 watts, there is no need for a huge radiator, it just fits.

Come on, tell us what harmful metals you found in LED lamps? Enlighten us on this issue!

About degradation. LEDs are afraid of high temperatures. If the lamp does not have an excellent heat sink, it will die. If there is. The stated period will be on. Take a look at the OSRAM website and see the results of the laboratory examination.
And in general! Everything else degrades even more quickly. DRLs lose 30% of the brightness of the light flux in the first 1000 hours.
And LEDs have an “extension”. For the first 1000 hours, the following happens: the LED increases brightness by ~5-10%, then loses up to 10-15%, then reaches the declared level and maintains it until the end. For proofs - again, go to the OSRAM website.
And one more thing. The same Nichia diodes will serve faithfully. Diodes from China are born dead.

About payback. If you have one light bulb, then yes, you will not pay for it in life. Do you have a business? Order a lighting design (large companies do it for free) or pick up a pencil yourself. You can pay for it in 3, 2, or less than a year. By increasing the lighting level. Proof - on the LEDEL website, for example.

About the nuisance of lighting. What kind of lamps do you have? How many Kelvin? The Chinese who burned out the phosphor in a month and came close to the ultraviolet? What is the flicker factor?
It’s the luminescent ones (including compact ones) that are unpleasant. Due to degradation, long ignition, hum during operation, stroboscopic effect. Well, all other lamps where the phosphor quickly burns out or the temperature was initially above 5500-6000 K.

About directional light. It's a pure lie. Yes, it is directional and that's an advantage, damn it!! Okay at home, back and forth, but in rooms with ceilings higher than 4-5 meters this is critical.
Directionality is a plus because:

No loss of luminous flux due to reflector
- the ceiling is not illuminated (why do you need it? Especially if it’s an office or workshop?)
- no loss due to the form factor (as in QCL, where the light bulb shines into itself)
- finally, it illuminates only what really needs to be illuminated

In other words, the direction of the light flux, coupled with the lenses, can further save money.

About quality components. Dear ones - what are they? Yes, more expensive than other lamps, but again - up to 5500 rubles. it simply cannot reach beyond “Armstrong” by definition. I have never seen such prices in my life.

About fluctuations in the network. How many lamps can withstand fluctuations of 1000 W? But LEDs can.

And many more advantages are simply forgotten. For example, absolute indifference to the number of switches on and off, to the duration of work without a break. Instant ignition even in cold weather. Resistance to mechanical damage (compared to CFLs, which you can’t even touch with your finger, that’s all). Well, etc.

Well, Yakov Kuznetsov. Please be kind. Tell us where you got so much false and categorical information.

A pressing problem when using LED lighting equipment as the main lighting is the periodic pulsation of the light flux. Why does the LED ceiling light blink when turned on? This is due to the characteristics of the LED matrix, which passes direct electric current exclusively in one direction, unlike incandescent lamps.

From an ordinary incandescent light bulb, the light also pulsates, but in this case the electrons can move in different directions, accordingly, the flickering frequency is similar to the frequency of an alternating electric current (50 Hz). Therefore, the organs of vision do not perceive such flickering. The amplitude of the light pulsation is also minimal due to the heating of the spiral. The light flow from such a light source has only one direction; accordingly, due to changes in the mains voltage, the brightness of the lighting also changes.

In this article:

Types and causes of LED element flickering

Conventionally, two types of flickering of an LED source can be distinguished:

• up to 50 Hz – low-frequency;
• more than 50 Hz – high-frequency.

The causes of flickering can be divided into three categories:

• constant drop in mains voltage;
• low mains voltage, which does not allow the power supply circuit of the LED source to function fully;
• malfunction, design features of the LED source power supply circuit.

Low frequency flickering of LED lamps

The amplitude of the alternating mains voltage changes with a frequency of 50 times/sec and has the form of a sinusoid. The luminescence of the matrix is ​​provided exclusively by positive and negative half-waves passing through the LED. If a light source equipped with LEDs blinks, this may be the reason for significant savings on the power supply by the manufacturer.

In inexpensive models of such lighting equipment, a single-bridge rectifier is often used to reduce its cost, designed to convert AC voltage to DC. A certain number of oscillations are cut off after the diode bridge, and by adding a capacitor to the electrical circuit, ripple is reduced. Such a scheme allows you to observe the pulsation of the light flux with a frequency of 25 times/sec.

Important! If the LED light continues to blink even after adding a normal bridge rectifier to the circuit, then the problem is most likely in the capacitor.

The capacitor, as a rule, accumulates charge at the amplitude maximum and returns it to the load at the minimum. At the output, the average voltage amplitude decreases, and the ripple becomes significantly smaller. If the resource capacity is insufficient, the capacitor is not enough to recharge the LED elements, whose brightness changes with each half-wave. According to sanitary standards, the pulsation of the light flux should not be more than 10 percent of the nominal intensity.

How can you prevent the LED light source from blinking in this situation?

You can prevent the blinking of an LED lamp using a rectifier bridge for diodes and a high-capacity capacitor.

It is also worth knowing that even the highest quality lighting equipment using diodes will flicker when the mains voltage changes. Effective mains voltage 310 V (220 V – nominal). Quite often, especially in the evening, when the network is significantly overloaded with many household electrical appliances, the voltage may drop to 180 V. This, accordingly, entails flickering of light sources.

Reasons for flickering of branded lighting devices

At low mains voltage, even if the light source is equipped with a capacitor of sufficient capacity, blinking may occur, since as a result of a decrease in amplitude, the capacitor will not have time to recharge. Such power surges occur periodically, but if they cause discomfort, you can additionally use a voltage stabilizer.

If the problems are completely corrected, but the LED elements continue to flicker when the lighting equipment is turned on, it is worth checking the quality of the contact connections on the switch or socket. Perhaps the contacts have oxidized.

Quite rarely, not the entire source blinks, but only several LED elements. Why does an individual LED of an LED ceiling lamp flicker when it is turned on when the neighboring lamps are working normally? This can happen if different types of crystals with different power ratings were used during the assembly process of the matrix. Unfortunately, it is useless to deal with such a problem, and, most likely, some LED elements will fail very quickly.

It is important to understand! The blinking of LED lighting fixtures at a low frequency, which can be detected visually, is detected instantly. It is enough just to determine why this is happening.

Reasons for flickering of an LED lighting device when turned on

The main reason why LED equipment may flicker is the poor quality of the LED matrix. Ripple in the output voltage of even a classic power supply circuit is inevitable. In high-quality diodes, the luminescence saturation in the established voltage range is almost identical, due to which any ripple is prevented.

In the case of a low-quality matrix, even if the voltage drops by 0.5, a change in the brightness of the light flux already occurs. In some cases, this situation can be corrected by installing a capacitor with a larger capacity. But such a lighting source is not recommended for living rooms.

Recommendation! When detecting the blinking of an LED chandelier, you should not ignore this phenomenon. This can lead to vision problems over time. You should definitely take the time to fix the problem, and if possible, return the low-quality light bulb to the seller.