What you need to know about LED lamps. What does the color temperature of LED lamps mean LED lamps and their characteristics

Information about what LED lamps are, what their principle of operation is and why they are better than other light sources. This topic is relevant because the future lies with them (diodes), so now we will review the most important technical characteristics of LED bulbs!

The device, in other words, the design of the LED lamp is represented by the following elements:

plastic light diffuser;
LEDs (usually at least 5 pieces);
installation board;
aluminum radiator (removes heat);
driver that converts the mains voltage;
ventilation holes (air circulates through them, as a result of which the driver cools);
base (is a conductor of electric current from the network).

It can be seen that inside the light bulb is a rather complex mechanism, the principle of operation of which differs from alternative light sources. It is because of the driver that is present in the circuit that the light can blink when connected to a dimmer. In this case, it is recommended to use special .

Characteristic

Main technical characteristics of LED lighting lamps:

Plinth type. It can be screw (marking E27, E14) and pin (G19, G13, GU10, etc.).
Power consumption - from 3 to 30 watts.
Rated voltage 220 V.
Luminous flux - from 250 Lm to 2500 Lm (average 100 Lm / 1 W).
Operating temperature range from -10 to +40°С.
Degree of protection (IP index, taken into account if the LED lamp will be installed in rooms with excessive moisture or dust, for example, in a bath).
Color temperature from 2700 to 6400 Kelvin.
Service life from 30 to 50 thousand hours.
Overall dimensions (length*width*height).
Weight (each product is individual).

Visual video review

Kinds

As such, a variety of LED lamps does not exist, which cannot be said about. Usually they can be distinguished by the type of base, working power and glow color.

ABOUT plinths we have already said above, considering the technical characteristics.

We draw your attention to the fact that it is rather difficult for a novice electrician to learn everything, especially since it is not necessary to do this at all. If you need to buy a new LED light bulb, it is best to take the old one to the store and show it to the seller.

Concerning working food, then the lamps can operate from 4, 12 and 220 V. The first group is used in decorative lighting of objects, the last two can be used as general lighting.

color glow LED lamps can be different: warm light, cold, daylight, etc. (the difference is shown in the photo below).

Application area

The scope of LEDs knows no limits. They can be used wherever possible: in supermarkets, in interior lighting, for, for decorative lighting of furniture and various architectural objects. Most often, light bulbs are used in private homes. They have proven themselves well because of the many advantages, which we will discuss later.

Advantages

Finally, we have moved on to the most interesting part of the article, in which we will consider the pros and cons of LED lamps for the home.

The main advantages are:

the highest energy savings (products save 10 times more electricity consumed than);
the highest luminous efficiency, which reaches a record 120 lm / 1 W;
the service life significantly exceeds 40,000 hours, which is also the highest indicator;
a wide range of products of various shapes, colors and dimensions;
high body strength;
does not harm the environment (does not have inert gases inside the flask);
works with power surges;
the number of on / off does not affect the service life;
heating is small (up to 60 degrees Celsius), so you can not be afraid when installing the product near flammable materials.

Flaws

The main disadvantage of the LED lamp is its high cost compared to other light sources.

Also, the disadvantages of products include:

the spectrum of luminescence can negatively affect a person's well-being;
the light is narrowly focused, which requires the installation of several LED bulbs to evenly illuminate a small room;
for efficient and long-term operation, it is necessary to purchase expensive radiators, drivers and power supplies;
the service life indicated on the package does not correspond to the real one (due to the fact that the crystals begin to spontaneously go out over time);
Most products do not function well

First of all, one should pay tribute to the huge variety, excellent design, simplicity, thoughtfulness and low price of products of the industry of the Middle Kingdom. A large range of China-made industrial LED luminaires is now available in the CIS market. In addition, a lot of locally assembled lamps are offered, but created from Chinese “constructors”. Almost all of these products are described by suppliers as extremely reliable, operating in the most difficult climatic conditions, in a wide range of supply voltages and, often, in an almost astronomical temperature range.

The question is natural, how much can you trust the declared characteristics and will the enterprise using such lamps receive the expected savings?

In our company, a lot of work has been done on the development, manufacture and testing of lamps with modular LEDs COB (Chip on Board - a crystal on a substrate, read COB). The main task in this case is to determine the temperature regimes that ensure long-term operation in the range of environmental exposure, which are established by the technical conditions. A mathematical apparatus for calculating cooling radiators was developed. The temperatures of finished products were measured with contact and non-contact meters, including a Fluke thermal imager.

Let's make a small digression to explain the importance of temperature conditions for the operation of lighting LEDs.

A model of a ten-watt white light LED module (Fig. 1) shows the main components. Crystals emitting blue light are placed on a massive, usually silver-plated copper substrate and filled with a colloidal solution of a yellow phosphor. In the luminaire, the module is mounted through a thin layer of heat-conducting paste on a radiator that dissipates heat into the environment.

Rice. 1. Model of 10 watt LED module

The maximum non-destructive temperature of operation of crystals specified by the developers usually does not exceed 135-150 °C. But such heating leads to degradation of the semiconductor structure and a gradual decrease in the luminous flux. In order to maintain the majority of the flow during long-term operation, the temperature of the crystals must be much lower.

Since it is difficult to directly measure the temperature of crystals, it is customary to normalize the substrate temperature, taking into account the thermal resistance of the crystal-substrate. The temperature difference between the crystals and the substrate varies depending on the power of the module, cooling modes and external conditions. On average, the temperature difference is approximately 20 °C.

Figure 2 shows the performance graph of LED modules depending on the operating temperature according to the Taiwanese company "Huey Jann Electronics Industry", which specializes in the production of COB LED modules. Preservation of 70% of the luminous flux after 50 thousand hours of operation is possible if the substrate temperature is not more than 60 °C, and the temperature of the crystals, respectively, does not exceed 80 °C.

What should be the cooler that provides this mode of operation? First of all, we are talking about passive radiators that dissipate heat due to natural air convection and radiation.

Many factors affect heat dissipation. Ambient temperature is of great importance. But the orientation of the radiator in space, configuration, material and surface properties of the radiator, and much more are also important. All these parameters will be considered another time. For now, we restrict ourselves to estimating the dimensions of the radiator relative to the ambient temperature.

Rice. 2. Dependence of the performance of LED modulesher temperature

One of the radiators commonly used in Chinese fixtures is shown in Figure 3. Such coolers are usually supplied with LED modules from 30 to 150 watts. The height of the radiator when installing a 50-watt module is 100 mm, the surface area is 3480 cm 2 . These dimensions are given by most luminaire manufacturers and are recommended by the radiator manufacturers themselves.

Rice. 3. Extruded aluminum radiator with a diameter of 160mm

Calculations show that on this heatsink with a 50-watt load and an ambient temperature of 40 °C, in the most favorable case, the substrate temperature will reach 100 °C. The lamp will work for some time, but the rapid decrease in light output will negate all the benefits of LED lighting. It is possible to provide normalized 50,000 hours of operation only if the ambient temperature does not exceed 10-15 °C. Obviously, this mode of operation is unacceptable. Even worse is the dissipation of more power, as heatsinks with a lower surface area per watt ratio are recommended and supplied.

Luminaires with a large number of low power surface mount LEDs are not considered here. Their use is much more important not in industrial, but in office or domestic applications. It can only be noted that although they have slightly different characteristics, the problems of heat removal and operation at extreme temperatures are also present there, and often to a much greater extent. To be fair, it's important to note that LED lighting manufacturer Edison has calculated that the cooling area required may be smaller than when using LED modules. Unfortunately, their calculations are too simplified and no supporting information is provided from the practice of application.

The problem of the high operating temperature of LED crystals in lighting technology has not gone unnoticed by manufacturers. Quite a few other cooler options are offered, but almost always the financial benefit prevails over the reliability indicators.

Alas, the marginal savings on materials in the products of the Chinese industry did not bypass the field of industrial lighting. The consumer has the right to be critical of the products offered and to demand from suppliers reasonable characteristics of a particular LED lamp.

When developing the cooling elements, our company proceeded from the requirements of the technical conditions, according to which the maximum ambient temperature of 40 °C should not affect the performance and service life of the luminaire.

Radiators calculated according to these requirements for 50 W of input power should have a cooling surface of about 200 dm 2. This is almost six times more than the Chinese counterparts. Smaller area results in higher crystal temperature and shorter life. In particular, on one of the experimental samples of a lamp with a 50 W LED by Edison, placed on a radiator with an area of 90 dm2, temperature measurements showed the following picture (Fig. 4). The figure shows the temperature in degrees Celsius. The maximum temperature of the crystals during this measurement is 89.8 °C, the temperature of the substrate is 60 °C, the ambient temperature during the measurement is 22 °C. And although this mode can be recognized as acceptable, any increase in ambient temperature or deterioration in convection conditions can lead to an accelerated decrease in the luminous flux.

Rice. 4. Image of a 50W LED taken with a Fluke thermal imager.

The size of the cooling area of 90 dm 2 was chosen based on the recommendations for the application of the Taiwanese company "Edison Opto Corporation". For 50 W modules, the company suggests using a cooler with an area of 70-73 dm 2 .

Thus, one should be very attentive to imported LED lighting equipment in terms of the declared durability parameters and operating conditions, if significant resource savings are expected from it, both in terms of reducing energy consumption and in terms of long service life.

N. N. GAVRILOV
Deputy technical director issues
LLC "Industrial Group Kalchenko and K"
[email protected]

The decline in retail prices for LED lamps has led to a sharp increase in their sales. However, the situation with the choice of quality goods for many still remains a dead end. If it was easy to buy an incandescent light bulb, with the advent of CFLs, the task has not become much more complicated due to a wider range and shades of emitted light. The parameters of LED lamps have significantly more points than the bulbs of previous generations.

But don't be afraid. To buy a good LED lamp, in-depth knowledge of the product is not needed. It is enough to deal with the main parameters once, so that later it is easy to navigate among the numbers indicated on the package. So what does the buyer need to know about LED lamps, and what technical characteristics to look for before buying?

Main characteristics

Following the proverb: "Meet by clothes ..." it is enough to pick up a box with a light bulb to get acquainted with its main technical characteristics. You should pay attention not to large bright numbers, but to a description of 10 or more positions printed in small print.

Light flow

At a time when the incandescent lamp was the No. 1 light source, the concept of luminous flux was of little interest to anyone. The brightness of the glow was determined by the nominal power of the light bulb. With the advent of LEDs, the power consumption of light sources has decreased significantly, and the efficiency has increased. Due to this, there was a saving, which is so often reminded of commercials.

Luminous flux (Ф, lm or lm) is a value that indicates the amount of light energy given off by a lighting device. Based on the value of the luminous flux, you can easily choose a replacement for an existing light bulb with a spiral. To do this, you can use the following table of correspondence. Along with the luminous flux, one can often come across the concept of "light output". It is defined as the ratio of luminous flux to power consumption and is measured in lm/W. This characteristic more fully reflects the efficiency of the radiation source. For example, a 10 W neutral light LED lamp emits a luminous flux of approximately 900-950 lm. So, its light output will be equal to 90-95 lm / W. This is about 7.5 times more than the equivalent with a 75 W coil with the same luminous flux.

It happens that after replacing an incandescent lamp with an LED one, its brightness is lower than stated. The first reason for this phenomenon is the installation of cheap Chinese LEDs. The second is underestimated power consumption. Both of these reasons indicate a poor quality product.

Also, the amount of luminous flux depends on the color temperature. In the case of LEDs, it is customary to indicate the luminous flux for neutral light (4500°K). The higher the color temperature, the greater the luminous flux and vice versa. The difference in light output between the same type of warm (2700°K) and cold (5300°K) LED lamps can be up to 20%.

Power

The power consumption of an LED lamp (P, W) is the second most important technical characteristic, which shows how much electricity an LED lamp consumes in 1 hour. The total power consumption is the sum of the power of the LEDs and the power of the driver. The most popular in our time are led lighting devices with a power of 5-13 W, which corresponds to 40-100 watt lamps with a filament.

High-quality pulse-type drivers consume no more than 10% of the total power.

As advertising, manufacturers often use the concept of "Equivalent power", which is expressed in the inscription on the package like 10 W = 75 W. This means that a 10 W LED lamp can be screwed in instead of the usual 75 W bulb without losing brightness. A difference of 7-8 times can be trusted. But if an inscription like 6 W = 60 W flaunts on the box, then often this is nothing more than an advertising gimmick, designed for the average buyer. This does not mean that the product is of poor quality, but the actual light output will most likely coincide with an incandescent lamp, not 60, but much less.

Supply voltage and frequency

The supply voltage (U, V) is usually indicated on the box as a range within which the manufacturer guarantees the normal operation of the product. For example, the parameter 176–264V indicates that the light bulb will confidently cope with any fluctuations in the mains voltage without a significant loss of brightness.

As a rule, an LED lamp with a built-in current driver has a wide input voltage range.

If the power source does not contain a high-quality stabilizer, then voltage drops in the power supply network will greatly affect the light output and affect the quality of lighting. In Russia, the most common are led-lamps powered by AC 230V with a frequency of 50/60 Hz and DC 12V.

Plinth type

The size of the base must be known in order to select a light bulb in accordance with the existing cartridge in the lamp. The bulk of LED lamps are produced under the E14 and E27 threaded base, which are the standard for Soviet-style wall, table and ceiling lamps. Not uncommon are LED lamps with a GU4, GU5.3 base, which replaced the halogen bulbs installed in spotlights and Chinese chandeliers with a remote control.

Colorful temperature

(TC, °K) indicates the hue of the emitted light. With regard to white LED lamps, the entire scale is conditionally divided into three parts: with warm, neutral and cold light. When choosing, it should be taken into account that warm tones (2700-3500°K) soothe and make you feel comfortable, while cold tones (from 5300°K) invigorate and excite the nervous system.
In this regard, it is recommended to use a warm glow for the home, and a neutral one in the kitchen, in the bathroom and for work. LED luminaires with TC≥5300°K are only suitable for specific work and as emergency lighting.

Scattering angle

By the angle of dispersion, one can judge the propagation of the light flux in space. This indicator depends on the design of the diffuser and the location of the LEDs. The norm for modern lamps for general use is ≥210°. For effective work with small details, it is better to buy a lamp with a dispersion angle of 120 ° and install it in a table lamp.

Dimmable

The possibility of dimming (lighting brightness control) of an LED lamp implies its correct operation from a dimmer (dimmer). Dimmable lamps are more expensive, as their electronic unit has a more complex device. An ordinary led bulb, when connected to a dimmer, will not work or will blink.

Ripple factor

(Kp) is not always given in the list of characteristics, despite the fact that it is of paramount importance and has an impact on health. The need to measure this parameter arose due to the presence of an electronic unit in the lamp and the high response of the LEDs. Low-quality power supplies are not able to perfectly smooth out the ripple of the output signal, as a result of which the LEDs begin to flicker at a certain frequency.

The ripple coefficient of LED lamps powered by a stable DC network is zero.

The best quality is considered to be LED lamps with Kp below 20%. In models with a current driver, the ripple factor does not exceed 1%. It is easy to determine this parameter in practice using an oscilloscope. To do this, you need to measure the amplitude of the variable component of the signal on the LEDs and divide it by the voltage measured at the output of the power supply.

By the frequency of the AC signal in the load, you can determine the type of driver used.

Operating temperature range

You should carefully consider this characteristic if you intend to operate the LED bulb in non-standard conditions: on the street, in production workshops. Some models are able to work correctly only in a narrow temperature range.

Color rendering index

Using the color rendering index (CRI or Ra), you can evaluate how natural the color of objects illuminated by an LED lamp is. Ra≥70 is considered good.

Degree of protection against moisture and dust

This parameter is expressed as IPXX, where XX is two digits indicating the degree of protection against solid objects and water. It may not be found on the specifications list if the lamp is intended for indoor use only.

Extra options

Product life

Service life is a very abstract characteristic of an LED lamp. The fact is that under the service life, the manufacturer understands the total operating time of the LEDs, and not the lamp. At the same time, the time between failures of the remaining parts of the circuit remains in great doubt. In addition, the quality of the body assembly and soldering of radio elements affects the operating time. In addition, not one manufacturer, due to the long service life, does not conduct full-fledged tests for the degradation of LEDs in a lamp. So the declared 30 thousand hours or more is a theoretical indicator, not a real parameter.

Flask type

Despite the fact that the type of bulb for many is not a critical technical parameter, in many models it is indicated in the first line. Usually the type and marking of the flask is expressed in alphanumeric code.

Weight

It is rare that anyone is interested in the weight of a product at the time of purchase, but for some lightweight lamps it matters.

Dimensions

How many manufacturers - so many cases that differ in appearance and dimensions. For example, 10 W LED lamps from different manufacturers may differ in length and width by more than 1 cm. When choosing a new led lamp for lighting, do not forget that it must fit in an existing lamp.

The market for LED products continues to develop dynamically, as a result of which the characteristics of the lamps change and improve. We hope that in the near future quality standards will be developed for LED lamps, which will simplify the task of the buyer with the choice. In the meantime, own knowledge is the main support when choosing and buying.

The main characteristics of led lamps

LED lamps differ from traditional models in the complexity of the device. If the incandescent lamp consists only of a tungsten filament connected by conductors to the base, then the led analogue has a set of LEDs. To make them work, an electronic board is mounted inside the light bulb housing. It contains a regulator with diodes and a capacitor, called a driver. Some models are equipped with sensors for control. In general, the LED lamp is an electronic light source that can be repaired, which highlights its advantages.

Power is one of the important characteristics of the product

For a led light source, power is not the main indicator of the brightness of the glow, but still it is one of the important characteristics. Power by definition is a measure of the conversion or rate of energy consumption. That is, this indicator is needed only to account for the consumption of electricity.

Considering the technical characteristics of LED lamps, it is necessary to pay attention to their advantages. The main one is economy. LED products consume negligible current compared to traditional incandescent lamps. On the packaging and case of each led product there is a power marking, and it ranges from 3 to 25 watts. Usually this indicator is indicated by the letters "W" or "P".

Everyone who is used to ordinary light bulbs does not understand how it is possible to screw in 10 W instead of 100 W in a chandelier to illuminate the entire room. The fact is that with less voltage consumption, LEDs emit more brightness. For example, a 10W LED lamp is as bright as a classic 75W light source. To compare the power of different lamps, there are special tables that allow you to choose the right product.

However, we must remember that Chinese LED lamps actually have less power than what is indicated on the package. A significant difference can be seen with a run-up of 5 watts. Such shortcomings must be immediately identified and it is better not to purchase such a product.

light temperature

LEDs have a different glow color. There are three main types:

daylight white light, corresponding to natural light;
warm light, similar to an incandescent lamp;
cold light is characterized by white color, but it has a blue tint.

Color temperature is measured in degrees Kelvin. This parameter is marked on the product with the letter "K". According to the numbers opposite it, you can determine the color of the light emitted by the LEDs. There is a special scale that helps determine the shade of light.

The colder the shade, the higher the glow temperature. For example, LEDs with a light temperature of 4000 K emit an analogue of daylight. It will not replace the sun's rays, but in the dark the brightness of such a lamp will be strong. The bedroom needs a calm atmosphere, which can be provided by warm light with an indicator of 2700 K. LED lighting devices with the ability to adjust the temperature of the light are very convenient to use at home. They allow you to change the color of the glow as you wish.

What voltage are LED bulbs rated for?

The operation of the LEDs is possible only from direct current with a voltage of 12 volts. In order for the LED bulb to work from an AC voltage of 220 volts, a driver is installed in its housing. This is a kind of voltage converter, which, passing 220 V through itself, gives a reduced voltage at the output.

However, there are light bulbs designed to operate on a 12 or 24 volt network. Most often they are used in cars. When buying a product, you need to pay attention to the voltage, otherwise an incorrectly selected light bulb may burn out.

Luminous flux

When buying a light bulb, a person is primarily interested in its brightness. There is such a thing as a luminous flux. It directly depends on the power of the product and is measured in Lumens. Light is obtained from voltage conversion. In this case, energy is spent on heat. If we take a tungsten filament, then only 70% goes to the glow, and the rest of the energy goes with heat, which shows the big drawbacks of outdated light sources. LEDs do not emit heat and all 100% of the energy goes to the brightness of the light.

Modern LED lamps can emit from 1 W to 80 Lm. There are developments of LEDs with a high indicator, but they are very expensive and are not used in everyday life. To compare the luminous flux of different lamps, there are special tables.

High-quality LEDs are very expensive, which encourages many manufacturers to put cheap counterparts. Naturally, the declared luminous flux of 80 Lm with 1 W cannot be obtained from such a product. In addition, you need to pay attention to the color of the flask. If it is matte, then the loss of luminous flux will be from 15 to 30%.

In many homes, it is now customary to put dimmers to adjust the brightness of the light. You need to know that for LED lamps there are special dimmers that change the pulse, not the voltage. If the LED lamp is connected through a conventional dimmer, when the voltage decreases, the luminous flux will not only decrease, but also be distorted. In addition to changing the shade of light, the efficiency of the LEDs themselves will also decrease.

Possibility of dimming lamps

Since we are talking about dimmers, it must be said right away that not all LED bulbs can be connected to a dimmer. It depends on the product driver, which is able or not able to respond to the dimmer. Usually, the manufacturer indicates this parameter on the packaging of the LED product. If the marking does not contain data on dimming, it is better to refuse such a product.

Color reproduction

Rarely anyone pays attention to this indicator. The color rendering index allows you to perceive the color of the illuminated object close to reality. For example, a value of 70 on a package label indicates that the color of an object illuminated by LEDs will match the real thing by 70%. That is, a white object will remain snow-white, a green surface will acquire the color of meadow grass, etc. The color rendering index is determined for each lamp in the laboratory.

Varieties of plinths

In addition to the main indicators, when buying an LED lamp, you must correctly select the base according to the base, otherwise it simply will not work to screw it into the lighting device. The most common are the E14 and E27 threaded bases. They are used in many home chandeliers. Although there are varieties of carob bases installed in different models of fixtures, for example, spotlights. A description of all types of LED lamp bases can be found in the table.

Lamps with bases, having the letter "G" in the designation, are usually designed for a voltage of 12 V. Outwardly, their pins are similar, but still they differ in thickness and distance between them. Products with E27 and E14 bases are used in a 220 V network, and bulbs with an E14 base have a maximum power of 6 watts.

Operating environment temperature

The manufacturer indicates the optimal operating temperature for LED lamps in the range from -40 to +40 ° C. Although in reality, the products work well in the northern regions at -55 ° C. You can skip this characteristic when buying lamps for the home.

Classification by degree of protection

The classification of the degree of protection depends on the conditions under which the light bulb can operate. If a traditional light bulb can withstand rain, then for an LED counterpart, moisture can be fatal if it gets on the electronic circuit. The degree of protection on the packaging is indicated by the letters "IP". There are numbers nearby, and the larger they are, the better the product is protected from moisture, dirt and mechanical impact on the case.

flicker

LEDs have the ability to create pulsating light. It will not be possible to see it with a normal eye, but with a large flicker, this will quickly affect eye fatigue. Flicker is very harmful to the eyes. For medical and children's institutions, this figure, according to the norms, should not exceed 20%. In cheap Chinese light bulbs, the pulsation rate can be up to 60%.

You can determine the flicker strength yourself with a simple pencil. They need to sharply hold in front of a glowing light bulb and look at the remaining trace. Smooth solid stripes indicate the norm. If after a stroke of a pencil an intermittent trace remains, such a lamp should be discarded. Its level of pulsation is very high.

Beam Angle

An incandescent lamp emits light in all directions of a transparent bulb. Sometimes this is good, but for targeted lighting, such radiation is characterized by large losses. LEDs emit light in a beam. That is, there are no losses, all the light purposefully goes to illuminate a certain object. In order for the bulb to be able to illuminate a large area, the LEDs under the bulb are placed at different angles.

For a night lamp or spotlight, light bulbs with a small scattering angle are suitable. In the house, the ideal choice would be products with a scattering angle of 180 o. If you want to perform general lighting of a large area, here you need to pay attention to light bulbs with a scattering angle of 360 °.

Flask size

The size of the product does not really apply to the characteristics, but still it requires due attention. Many chandeliers and other similar lighting fixtures have shades of limited size. This must be taken into account when choosing a light bulb, as it can ugly stick out of the ceiling or sink deep inside, which will take away some of the light. Worse, if the light bulb does not enter the ceiling at all.

In terms of dimensions, we can say that the greater the power, the larger, of course, the size of the product case. The shape of the bulb can also be different, in the form of a candle, pear, etc. Recently, 15 W models with a small body have appeared on the market, similar to less powerful lamps from 7 to 8 W. However, they do not overheat due to the special materials used.

Lifetime

Manufacturers guarantee the performance of LED products up to 30 thousand hours. If you count this in days, assuming a constant glow, you get more than three years. However, no one has a light at home for days. The lamp shines for no more than 8 hours a day. With this use, the LEDs will last up to 10 years.

Home light bulbs with E27 base

For home use, the LED light source with an E27 screw base is ideal. This is due to interchangeability with traditional incandescent lamps. It is enough to unscrew one lamp from the cartridge and replace it with another. If we talk about the technical characteristics of the LED lamp E27, then all the parameters are identical to those discussed above.

Whatever the types of LED lamps, they all have the characteristics considered. This must be taken into account when choosing a product in order to select a suitable light source.

For more than a hundred years, people have been using incandescent lamps to light their homes, cities, workplaces and industrial premises. And only in the last few decades, alternative lighting devices have begun to develop widely. To replace the filaments, it was proposed to use the well-known , and they are already being replaced by LEDs.

The cheaper semiconductor LEDs, in particular, allow them to be used much more widely than usual. Not only in equipment as a replacement for signal lamps or for decorative design, but also as a full-fledged replacement for lighting fixtures. They have a wider range of consumer characteristics, ranging from luminous flux, consumption, size and ending with the color of the radiation itself.

Main technical characteristics

To decide on the choice of a suitable LED lamp, you can only familiarize yourself with its technical characteristics. They are described in detail on the packaging or are presented in abbreviated form on the device itself in the form of markings. All characteristics and characteristic values are presented below:

Plinth and body type (E27, E14, G5, G13, GU4, GU5.3);
Power consumption 3-20W;
Supply voltage from 12V DC to 220V AC;
Radiation power, radiation efficiency;
Warmth (hue) of the emitted light 2700-6700K;
The ability to adjust the brightness;
Light distribution;
Medium temperature range
Design

The most common type of base is E27, like most incandescent lamps that are used in the home. In lampshades and nightlights, the smaller size E14 is more common. Even smaller E14 can only be found in equipment, such as a refrigerator or microwave oven.

For or the largest plinth E40 is used.

LED lamps are available in all common types of socles:

To replace daylight fluorescent lamps, LEDs are used in a tubular housing with two-pin terminals G5, G13.

Lighting systems mounted in false ceilings use sockets with two contact leads. This version is marked as GU4, GU5.3, GU10, GU13. In this case, LED lamps are more often used at a voltage of 12-24 volts, and, accordingly, the base conclusions are quite thin.

Power consumption

Power consumption plays a significant role, in fact, only for calculating the total consumption of lighting in a room or a building as a whole. For all types of LED lamps, the power consumption varies from 3 to 25 watts. It is impossible to unambiguously determine the degree of brightness or power of the light flux by the power consumption.

Direct or variable current source

The LEDs themselves operate on direct current in a 12 V network. For their operation, special drivers are used, circuits that bring the external supply voltage to a suitable one for the element itself. With the help of drivers, it is possible to connect to a standard alternating voltage of 220 volts in a household electrical network. In addition, there are versions for AC and DC voltages of 12-24 V.

It is important to clarify in advance what voltage will be used for power, and select the appropriate model. With the wrong choice, at best, the lamp simply will not work. At worst, it will burn out if too much voltage is applied.

LED lamps equipped with a driver are much easier to tolerate surges that occur in the mains. If incandescent lamps dim when the voltage drops, and when they increase, they light up brighter and can burn out, then the LED elements in a fairly wide voltage range shine equally effectively.

Luminous flux of LED lamp

The most significant parameter for the consumer is the power of light emission from the lamp and its efficiency. It is measured in lumens (Lm) or Lm/W. The second parameter determines the ratio of radiation power to power consumption, in fact, showing its efficiency.

If an incandescent lamp has an efficiency of only 10-15 Lm / W, then for LEDs it is already 70-90 Lm / W. That is, for every watt consumed, a lamp with an LED produces almost 10 times more luminous flux power.

In order to evaluate the luminosity in comparison with a filament, it should be taken into account that:

For a 40W lamp, the luminous flux is approximately 360 Lm.
For 60W - 600 lm.
For 100W - 1000 Lm.

Table comparing the luminous flux of LED lamps compared to incandescent and fluorescent lamps:

The packaging may indicate either the power of the luminous flux or efficiency (light output) or a comparative characteristic, equating it to a filament of the same luminosity. The latter option is more common, although it is not as clear as the first two.

LED color temperature

One of the most important differences between LED elements and incandescent lamps is the color of the emitted light. It can be selected in a fairly wide range, in contrast to the warm yellowish glow standard for a filament.

The shade of light is determined by the color temperature scale, built on the basis of the color of the glow of the metal when it is hot. The temperature of the yellow warm glow of the metal corresponds to a temperature of 2700K (degrees Kelvin).

For white color, daylight, the temperature corresponds to 4500-6000K. At the same time, at the lower border, white light still gives off a slightly yellow tint. Everything above 6500 is a bluish cold color.

It is best to choose the color of the radiation based on personal preferences or in order to present the interior decoration of the room in the best possible way.

Dimmable LED Lamps - Dimmable

LED lamps can be dimmed. In this they favorably differ from luminescent housekeepers. To control the LED, a special dimmer device is used. It generates power in the form of pulses. The lower the pulse frequency, the dimmer the diode burns, and vice versa, the higher the frequency, the brighter it is.

The user will not see the blinking frequency of the diode and will not feel discomfort from flickering, because it is about 200-300 kHz. The human eye can perceive the frequency of blinking only at frequencies up to 200 Hz with increased sensitivity.

However, it should be borne in mind that not all LED lamps can be dimmed. The limitation is imposed by the built-in driver for the LED, which is deliberately configured for a certain frequency of operation or only for linear power. Lamps with the ability to adjust are called dimmer, which must be marked on the package.

Light distribution of the lamp - the direction of the light flux

The LED itself can only emit light in one direction, and often in a small sector in front of it. This is not a problem when it comes to narrowly focused light sources, such as a night lamp, where a narrowly focused beam of light is already preferable.

Another thing is if the lamp should illuminate everything around and as evenly as possible. To do this, a diffuser made of frosted polycarbonate is placed in front of the LED. Additionally, several diodes can be used instead of one, directed at different angles.

Medium temperature range

Unlike fluorescent lamps, which mostly operate only at an ambient temperature of +5C to +45C, LED lamps operate in the range from -40 to +40. This allows them to be used in conditions where only gas-discharge, mercury, sodium or incandescent lamps could previously be used.

Other parameters of LED lamps

In addition to the above parameters, there are several more. The LED during operation emits not only light, but also heat. Significantly smaller than an incandescent lamp, but still noticeable.

The main problem is that the heat is not distributed along with the light, but in the opposite direction towards the substrate of the diode itself. When overheated, the semiconductor may lose some of its characteristics or even fail.

In order to solve this problem, a radiator is used, and it is an indispensable and integral part of a modern LED lamp. The most commonly used aluminum radiator with fins to increase the heat distribution area. The more powerful the lamp, the larger and more massive the radiator is used. Structurally, it is performed as part of the base.

By the presence of a radiator and its quality, you can determine the quality of the lamp itself and how long it can work. If it does not have a radiator at all, or it is made of thin tin, then it is better not to purchase one, unless we are talking about the most low-power options for 2-3 watts.

In conclusion, it is worth listing the main advantages and disadvantages of LED lighting elements over other analogues.

Pros:

economical in terms of power consumption 3-20W;
high efficiency in terms of light output for each consumed watt of power 70-90 lm / W;
pure glow color, narrow spectrum;
lack of ultraviolet radiation;
low level of electromagnetic ripples<1%;
uniform light, no noticeable flicker;
directional glow;
a wide range of colors and lighting shades 2700-6700K;
working life up to 50,000 hours;
strong and durable case made of polycarbonate or tempered glass;
a large selection of plinth designs and installation methods;
adaptation to any supply voltage 12-220V;
manufacturer's warranty.

Minuses:

still quite expensive
not well understood health effects

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