What LEDs are used in flashlights. Military and special devices. Flashing LEDs - what is it for?

LED operation is based on semiconductor knowledge and practice. They have been known to mankind for almost half a century. Moreover, all the raw materials for the manufacture of such lighting devices have been familiar for more than 20 years. However, it was only recently that we succeeded in connecting them correctly and obtaining impressive LED characteristics. This lighting represents an innovative breakthrough, making diodes quite efficient and environmentally friendly. It is believed that such accessories are much more economical than classic incandescent lamps. They can be used in various areas of human life, not only because of ease of use, but also due to the desired glow temperature.

Characteristics

In order to understand the principle of operation of devices, you need to know following characteristics LEDs:

1. Luminous flux. This parameter is measured in lumens (Lm) and shows the amount of light that the lamp produces. The higher this indicator is, the brighter it will shine.
2. Power consumption is measured in Watts (W). The smaller this parameter, the more economical the energy consumption.
3. Light output, its unit of measurement is considered to be Lm/W. It is central to the operation and efficiency of the entire lighting device.
4. Radiation direction diagram. Parameter of the luminous intensity curve, due to which the fluxes emitted by the diodes are distributed.
5. Color temperature (shades of white light). It is measured in degrees Kelvin in the permissible range from 2700 to 7000 K. The shade of a warm color is considered the most favorable for the eyes, which varies up to 4000 K, and all indicators that are higher are usually referred to as “cool white”. Most often, lamps with warm light are much more expensive than those with cold light, since this is directly related to the features of their production.
6.Color rendering index. This value shows how truthfully the color of an object illuminated by the selected lamps will be displayed. The higher this parameter, the more truthfully the shade of the original object is conveyed.
7. Performance of lighting devices. The most the right decision is the choice of branded manufacturing plants, since such companies can provide more accurate technical characteristics of LEDs, thanks to which the device will last the stated operating time. Also, such lamps provide protection against voltage surges and overheating.
8. Device size. There is no need to judge the advantages and disadvantages based on the size of the crystal. It does not matter whether the LED is large or small, the most important thing is its power.

Considering these characteristics of LEDs, you can choose exactly the device that will give the maximum effect from its intended use.

Quality indicators

The quality indicators of an LED product can be judged based on the following criteria:
- manufacturer (preferably products from well-known companies that publish open data on the reliability of their devices);
- the use of a specially designed design and shape for the fastest possible heat removal, regulating the temperature during operation of the chip;
- optical (lighting) specifications of the LED lamp, which can be obtained from an independent laboratory or manufacturer;
- high-quality guarantees;
- results of long-term tests of the functioning of devices.

White varieties

Most often in everyday life, for decoration and lighting, white LEDs are used, the characteristics of which depend on their tone.

• Warm White light: his Colorful temperature is 2700 K, and it has a slight yellowish tint, similar to the flame that a candle emits. This shade is typical for incandescent lamps; it calms and relaxes. It is important to note that using a matte or transparent shade will change the shade to a softer or richer one. This type of light is not the main one, but it is perfect for additional and decorative lighting and will be ideal for installation in bedrooms. Thanks to it, you can create harmony and homely warmth in the room.
• Natural white light: Its color temperature is 4200K, it is the most popular and most commonly used. Suitable for use as the main source of lighting for both commercial and domestic premises. Can be used on all types of surfaces, such as a kitchen countertop or a desk in an office. Like warm light, natural has several shades. Fixtures and lamps with matte dispersion will have a completely different saturation spectrum than devices with a transparent bulb. It helps produce more accurate and directional light than matte, through which soft highlights of an unobtrusive shade are emitted.
• Cool white light: its color temperature is 6000 K. It has a peculiar bluish tint. This tone is very bright and is most often used for offices and also as local lighting. It has become quite widespread in parking lots, at entrances, in local areas, as well as in parks, alleys and squares. Often installed to illuminate street advertisements, commercial signs, and more.

Types of LEDs

There are a variety of LEDs, the parameters and characteristics of which completely depend on their types:

1.Blinking: used in indicators to attract attention. This type is practically no different from the usual ones, however, for its production a built-in multivibrator circuit is used, which flickers with a break of 1 second. The main types of such diodes are single-color light rays, more complex in their characteristics can flash in several shades alternately or simultaneously, thanks to the RGB parameter.

2. Multi-color blinking LEDs, the characteristics of which are quite diverse and can be represented in two different crystals, working one towards the other, therefore, when the first one lights up, the second one goes out completely. With the help of a current that moves in the initial direction, one color appears, and in the opposite direction another color appears. Thanks to this type of work, a third color is formed, since the two main ones are mixed.

3.Tri-color LEDs, the parameters and characteristics of which consist in the presence of several light-emitting diodes, not connected to each other, but combined in one housing. They work separately, they can light up at the same time, but their controls remain completely different.

4. RGB light emitting diodes with blue, red and green elements, which use a connection with four wires and a single common cathode or anode.

5. Monochrome displays with seven segments, as well as using starburst format. Such screens show all the numbers, and some even specific set letters Using Starburst allows all symbols to be displayed.

Alphanumeric and numeric displays, which were quite common in the 80s, became less popular after the advent of LCD monitors.

Advantages of LED lighting

Being relatively new technology, LEDs are in most cases superior to many lighting sources in terms of light quality, energy efficiency, environmental friendliness and cost-effectiveness. The characteristics of LEDs are superior to those of high-incandescent lamps in almost all areas of application, but such lighting cannot yet solve all the tasks. White diodes have already proven themselves to be an excellent alternative to fluorescent tubular and high-pressure lamps. But it still has to pass a small amount of time until such technologies begin to be used in the public system.

What does the SMD marking mean?

The decoding of this indicator sounds like Surface Mounted Device, which translated into Russian means “a device that is mounted on a surface.” Such a device is a diode, and the surface in our case is the base of the tape.

Any SMD LEDs, the characteristics of which are similar to those of all other similar lamps, consist of several crystals placed in a housing with contact leads, as well as lenses that form the luminous flux. It is emitted by semiconductors and directed into a miniature optical system, which is formed by spherical reflectors, as well as transparent body the diode itself.

What other characteristics do SMD LEDs have? The marking, which is represented by numbers on the tape, shows the dimensions of the crystal in millimeters. The SMD-based strip bends very well in the longitudinal direction.

What does the DIP LED marking mean?

There are also LEDs on sale, the characteristics of which are very similar to SMD. According to their own technical parameters they are a cylindrical body, which is placed on the end strip. This type has good silicone protection. The numbers that are present in the marking, as well as for SMD, indicate the diameter of the diode.

Such crystals can be used to illuminate furniture, only for glass shelves. Unlike the previous tape, this type bends very well in the transverse direction.

Parameters of a high-quality LED flashlight

Today, you can buy a large number of conventional flashlights on the market, but they are being actively replaced by LED ones. This happened primarily due to the fact that the latter give much brighter light.

In order to choose the right LEDs for flashlights, the characteristics of which are very diverse, it is necessary to take into account all the basic requirements of the buyer when choosing. What you need to pay attention to is the type of beam, it can be wide or narrow. Which type to choose depends on the future application. For example, in order to be able to see objects at a distance of 30 meters, it is better to choose a flashlight with a wide beam, while models with a narrow beam can illuminate distant objects well. Most often, such lighting is provided by tactical devices used by tourists, hunters and cyclists.

One more important factor The type of power supply that affects the operation of the flashlight is the type of power supply. For the simplest household appliances, ordinary AA or AAA batteries are used, but for strong and powerful devices this volume will not be enough. In this case, you need to use lithium-ion batteries, which can work continuously for 5 hours.

It is worth paying attention to LEDs for flashlights, the brightness characteristics of which differ from each other by no more than 40%. The quality of the selected devices is guaranteed by the presence of markings. In cases where it is absent, we can talk about a non-certified product, most often made in China.

LEDs from CREE

This company specializes in the manufacture of high-quality and bright diodes. She was one of the first to develop new white light bulbs, thereby establishing new milestone in the industry.

CREE LEDs, the characteristics of which are presented, remain competitive in their industry:

Have record values luminous flux, reaching 345 lumens at a current of 1000 mA;
- thermal resistance at a low level;
- relatively wide angle of study;
- miniature, evenly distributed crystal;
- maximum current reception up to 1500 mA;
- improved silicone lens instead of glass;
- maximum temperature crystal operation 150 °C.

As you can see, such technologies are just coming into force and bring exceptional benefits from their use. Every day new discoveries are made, LED lamps become more economical and brighter, thanks to which they rightfully begin to occupy a leading place in the lighting arena.

Features of SMD 5050 tapes

LEDs in this series have a size of 5x5 mm and a luminous flux depending on color, which ranges from 2 to 8 lumens. They can also be divided according to the degree of moisture protection - IP20 and IP65, since they have two different types coatings, namely polyurethane and silicone. The former can only be placed indoors, while the latter, accordingly, are suitable for the street, since they are not afraid of excessive humidity.

5050 LEDs, whose characteristics and properties help create bright light, consist of three crystals with different or identical diodes in one package. Multi-colored lamps called RGB (red-green-blue), after connecting controllers you can get a variety of colors.

The main technical characteristics are:

Transparent and rigid polyurethane coating;
- high-quality soldering;
- the number of LEDs per 1 meter is 60 pieces;
- cutting ratio - 3 crystals, which is 50 mm;
- width, length, height in mm 10 x 5000 x 3;
- the power supply is connected to 12V or 24V DC.

Features of SMD5730 tapes

Adopting high-efficiency 5730 LEDs, the characteristics and properties of high thermal conductivity and low resistance ensure a long service life of the device. They are resistant to vibration and high humidity environment and temperature changes. They are small enough, have a wide beam angle and are perfect for any surfaces during installation. They can be purchased in reels and tapes.

Many people like to use 5730 LEDs, whose characteristics are suitable for use in various devices, which is very convenient for both ordinary users and designers. They are indispensable for lighting trade and office premises, where not only high energy efficiency is considered important, but also comfortable light transmission.

For those who use LEDs, markings, characteristics and properties are of no small importance. They have a number of advantages over their predecessors, namely:

Phosphor white LEDs rated power 0.5 W are distinguished by a significant service life, stable performance and high-quality performance;
- high resistance to temperature changes, vibrations and high environmental humidity;
- degradation of the luminous flux - no more than 1% for 3000 hours of operation;
- the body is made of high-quality heat-resistant polymer that can withstand up to +250 °C;
- LEDs are fully suitable for reflow soldering.

When selecting or assembling a new LED flashlight Be sure to pay attention to the LED used. If the only task of the future flashlight is to illuminate a dark entrance, then almost any bright white LED will cope with this task. Another thing is the desire to get a portable lighting device with parameters for more difficult task. In this case, the luminous flux is of particular importance, that is, the ability of the flashlight to produce a sufficiently powerful beam and illuminate a wide area of ​​​​space.

Which LED brands are in the top positions, and what characteristics do their light-emitting diodes used in flashlights have?

Main characteristics

The quality of light emitted by the flashlight is controlled by the LED, which can be called, without exaggeration, the heart of the device. The stability of a flashlight's heart rate depends on many parameters, the main ones being current consumption, luminous flux and color temperature. The trendsetter is considered to be the company Cree, which produces wide range super-bright and powerful LEDs, including for flashlights. Modern flashlights are designed with a single LED with a power of 1, 2, or 3 W. In one-watt version the value direct current is about 350 mA with a voltage drop of 2.8-2.9 V.

The current and voltage of a two-watt LED is about 700 mA and 3.0 V, respectively, and a similar 3 W crystal consumes approximately 1000 mA and 3.2 V. The electrical indicators given are typical for LED models of the world's leading brands.

The intensity of radiation, also called luminous flux, depends on the manufacturer and family of the LED. The rated value of the luminous flux of high-power LEDs is usually measured at the maximum permissible operating current. The manufacturer of branded flashlights, along with the type of LED installed, indicates the number of lumens produced by the product.

Unfortunately, flashlight packaging often indicates inflated characteristics, including luminous flux. The reason for this is simple - any manufacturer wants to sell as much product as possible.

Luminous flux is inextricably linked with light. Modern light-emitting diodes are capable of emitting a luminous flux of up to 200 lumens per 1 watt and can be produced with any glow temperature: from yellowish warm to cool white. Lanterns with warm white radiation (T≤3500°K) are most pleasing to the eye, but less bright. Lighting with a neutral color temperature (T=4000-5500°K) allows you to view fine details more effectively. Cool white beam (T≥6500°K) in powerful flashlights with a long illumination range, but irritates the eyes during prolonged use.
Due to the impossibility of making accurate calculations, the lifespan of LEDs is calculated by extrapolation. At a temperature of 25-50 °C, their crystal service life can exceed 200 thousand hours, but this is not economically justified. Therefore, manufacturers allow an increase operating temperature up to 85°C, thus saving on cooling costs. Exceeding the threshold of 150°C leads to irreversible processes of crystal burnout and loss of brightness.

Color rendering index (CRI) is a qualitative indicator characterizing the ability of an LED to illuminate objects without distorting them. real color. For LED lighting sources, including flashlights, a color rendering index of 75 CRI or higher is considered good.

An important element of an LED is the lens. It sets the angle of dispersion of the light flux, and therefore determines the range of the beam. The technical characteristics of LEDs must indicate the value of the radiation angle. For each model, this parameter is individual and can vary from 20 to 240 degrees. Powerful LEDs for flashlights have an angle of 90-120° and, as a rule, are equipped with a reflector with an additional lens in the housing.

Despite the sharp leap in the development of high-power multi-chip LEDs, world leaders continue to produce less powerful LEDs. They are produced in small cases, not exceeding 10 mm in width or diameter. The typical current value of such light-emitting diodes does not exceed 70 mA, and the luminous flux is 50 lm. Powerful flashlights based on them are gradually disappearing from store shelves due to worse technical characteristics and the need for series-parallel connection to increase brightness. Compared to one powerful crystal, the reliability of the circuit and the dispersion angle of several such elements in one package are much worse.

Separately, it is worth noting the four-pin LEDs in the P4 “SuperFlux” or “Piranha” package, which have improved technical characteristics. Piranha LEDs have two important advantages that make them in demand:

• distribute the light flux more evenly;
• do not require heat removal;
• have low cost.

5 largest manufacturers

A portable flashlight should not only be ergonomic, but also equipped with a reliable LED source with a high working life without loss of brightness. In order not to make a mistake with your choice, preference should be given to world-class manufacturers of LED products.

Division of the Japanese company Nichia for a long time held a leading position in the production of LEDs of all types. Due to the high cost of products and increasing competition from China and Taiwan, today it is becoming increasingly rare to find their LEDs in flashlights on the European market. However, the world needs Nichia as an engine of progress. After all, the developments of Japanese companies are taken as a basis by their Chinese and Taiwanese colleagues.
Powerful LEDs for flashlights from around the world famous company Cree hold the lead not only on the American continent. Standing out with lower cost and high quality, LEDs from Cree are available to everyone on the European continent. A rechargeable flashlight with a powerful crystal from an American brand is a reliable friend on a hike, night fishing etc.
Philips Lumileds is a European manufacturer of wide-spectrum light-emitting diodes. The company has achieved certain progress in the construction of outdoor lighting systems of functional and architectural significance. Philips Lumileds developers take an integrated approach to building LED systems, taking into account their design, degree of protection and ease of use.
The South Korean corporation Samsung, well known in Russia, promptly financed its division to search for new LED solutions and now has a full production cycle of emitting diodes. Samsung is not limited to release LED backlight for your own displays. Their successes have spread to other market segments: high-power LEDs (including for flashlights), ultra-bright flash elements, as well as indoor and outdoor lighting modules.
Osram Opto Semiconductors has become famous for the excellent characteristics of LEDs from the Duris series, which are distinguished by their high luminous efficiency and color rendering index. The German company relied on the implementation LED technologies into industrial sectors, focusing on the production of ready-made specialized lamps and fixtures. Osram laboratories improve the performance of light-emitting diodes not only visible spectrum, but also make discoveries in the IR, UV and laser fields.

Reports from scientists along with development news artificial lighting indicate continued healthy competition between large corporations. Positive trends We see the development of LED technology in constantly updated model range flashlights that surprise with their long-range beam, high degree of protection, ability to charge from solar energy and other know-how.

Read also

Suitable for various powers. The luminous efficiency of the device should not exceed 80 lm. You should also pay attention to the driver. Typically it is installed with an output capacitor. Some models have an amplifier. On average, their current consumption is 3 A.

If we consider sensitive modifications, then they have a voltage surge protection system installed. In order to understand the issue in more detail, it is necessary to consider specific models.

Circuits with capacitive capacitors

LED flashlight circuits with capacitors include wave filters. In this case, triggers are used on a semiconductor basis. As a rule, their output voltage does not exceed 20 V. Converters are used to reduce sensitivity. Drivers for models are installed with different throughput. If we consider a 30 V LED, then it has a transceiver.

Using snubber capacitors

The LED circuit with a damping capacitor includes contact filters. In total, the models have two converters. The driver is connected to the LED through a winding. Some modifications have a compact transceiver. Most often it is used with an amplifier.

Characteristics of LED marked 530

These are universal for flashlights. The characteristics of the devices indicate a high conductivity coefficient. LEDs are produced for 20 and 25 V. If we consider the first option, the luminous efficiency of the device is on average 60 lm. The color rendering coefficient in this case depends on the conductivity of the transceiver. For many models, the amplifier is used without a converter.

The current consumption of LEDs does not exceed 2.5 A. Switching time of models of this type is about 6 ms. If we consider 25 V LEDs, then they only use a pulse transceiver. Many models have one amplifier. The driver is connected using a converter. The luminous flux parameter is around 65 lm. The turn-on time for LEDs of this type is 7 ms.

LED 640 (LEDs for flashlights): characteristics, photos

The LED circuit of this series includes a phase-type converter. Filters are used to increase sensitivity. Amplifiers are most often used on a magnetic basis. The luminous efficiency parameter in the devices is 65 lm. It is also important to note that the current consumption does not exceed 4.2 A. The frequency deviation averages 4 Hz.

The service life of this type of LED is three years. The disadvantages of the devices include the low current conductivity of the drivers. Their brightness indicator is extremely low. Light output, as a rule, does not exceed 5%. These 6 volt flashlight LEDs work well.

Using LED 765

The 12V unit uses the specified flashlight LEDs. The 2014 specifications indicate an increased level of current consumption. this modification is equal to 45 lm. It is also important to note that the model is suitable for switching amplifiers. The driver in the device is used at 6.5 microns. Phase interference with these LEDs is not a problem.

Luminous efficiency averages 70 lm. The service life of the device does not exceed four years. The color rendering coefficient is 80%. The model is perfect for flashlights with regulators. In this case, the devices are connected via a contact adapter.

LED 840 circuit

These are compact and universal LEDs for flashlights. The characteristics of the model primarily indicate a high dispersion rate. Its pulsation coefficient reaches a maximum of 80%. The device turn-on time is 5 ms. According to experts, the model is excellent for 12 V flashlights. The amplifier in the device is of the absorbing type.

In total, the model has two drivers. The LED trigger is used with an adapter. To solve problems with heat loss, a capacitor is used as standard. The luminous efficiency of the presented model is 67 lm. The conductivity indicator does not exceed 10 microns. In this case, the current consumption is 0.3. Minimum permissible temperature LEDs are only -10 degrees. The model does not have an overheating protection system.

Characteristics of LED 827

Models with are suitable for the indicated LEDs for flashlights. The characteristics of the device indicate the presence of high-quality wired transceivers. The amplifiers of the model are installed in an open type. The device uses two capacitors in total. They do an excellent job of minimizing heat loss. The minimum permissible LED temperature is -15 degrees.

They are not suitable for 15V flashlights. The protection system in the device is used with filters. The model has a driver for 4.5 microns. Current consumption is no more than 4 A. The LED turn-on time is on average 6 ms. The pulsation coefficient of the model is 85%. Luminous efficiency, as a rule, does not exceed 50 lm.

LEDs LED 830

These flashlight LEDs are perfect for 10V devices. Their characteristics are quite good. The turn-on time is 5 ms, the luminous efficiency is 65 lm, and the current consumption is 3.3 A. The model uses a phase-type converter. According to experts, the model is not suitable for 15 V flashlights.

There is no transceiver in the indicated LED. The driver itself is installed with a conductivity of 4.5 microns. Problems with current rectification are solved thanks to capacitors. The pulsation coefficient of the model reaches a maximum of 90%. The service life of the presented device is three years. The minimum permissible LED temperature does not exceed -20 degrees.

Characteristics of LED series LB

The specified LED is suitable for 15 V flashlights. The characteristics of the model indicate an increased color rendering coefficient. The output voltage of the model is 15 V. The filter in the device is of the wave type. The driver in this case is connected via a conductor. The LED transceiver is used with an adapter. The capacitor is installed in an open type. The model has two triggers in total. In this case, the energy consumption is 2.5 A.

The luminous flux of the device reaches a maximum of 65 lm. The pulsation coefficient of the model is insignificant. Also, the disadvantages can be attributed to the low level of the minimum permissible temperature. A Chinese LED flashlight turns on in 4 ms. The model rarely has problems with current rectification. This model is not suitable for 10V flashlights. The LED does not have an overheating protection system. The frequency deviation of the model is 5 Hz. These Cree flashlight LEDs work great.

daylight

These LEDs for flashlights are produced with high-quality pulse-type amplifiers. In total, the model has two capacitors. The transceiver is standard wired type. It is also important to note that the maximum frequency deviation is 4 Hz. The current consumption of the LED does not exceed 3 A. The luminous flux of the device is 70 lm. The light output of the model is insignificant.

According to experts, the model is excellent for 12 V flashlights. The driver is directly connected via an adapter. On average, the turn-on time is 6 ms. The service life of the presented model is 5 years. The minimum permissible LED temperature is -15 degrees.

TB series (warm white light)

These are simple and inexpensive LEDs for flashlights. The characteristics of the device indicate that the color rendering coefficient of the model is low. It is also important to note that the output voltage is 8 V. The LED lifespan is three years. The modification's transceiver is used high sensitivity. In total, the model has two capacitors. According to experts, the device is not suitable for 10 V flashlights. The current consumption of the model is 2 A. The LED luminous flux reaches a maximum of 65 lm.

Problems with negative modulation are rare. The disadvantages include only a small conductivity parameter. Filters in the device are used only of the open type. The maximum frequency deviation of the LED reaches 5 Hz. To reduce the sensitivity, a trigger is used on the capacitor. The pulsation coefficient of the model is insignificant. To install the LED, a wire adapter is required.

Features of LED models of the LHB series (cold white light)

These LEDs have good characteristics. First of all, it is important to note that the color rendering coefficient is 80%. In this case, the service life is three years. The direct output voltage is 12 V. The turn-on time is 5 ms. In this case, the amplifier is used with an adapter. According to experts, problems with heat loss are rare. The model's capacitors are of the pass-through type.

Since the invention of electric lighting, scientists have been creating more and more economical sources. But a real breakthrough in this area was the invention of LEDs, which are not inferior in luminous flux to their predecessors, but consume many times less electricity. Their creation, starting from the first indicator element and ending with the brightest Cree diode today, was preceded by great amount work. Today we will try to analyze the various characteristics of LEDs, find out how these elements have evolved and how they are classified.

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Operating principle and design of light diodes

LEDs are distinguished from conventional lighting devices by the absence of a filament, a fragile bulb and gas in it. This is a fundamentally different element from them. Scientifically speaking, the glow is created due to the presence of p- and n-type materials in it. The former accumulate a positive charge, and the latter accumulate a negative charge. P-type materials accumulate electrons, while n-type materials form holes (places where electrons are missing). At the moment an electric charge appears on the contacts, they rush to the p-n junction, where each electron is injected into the p-type. From the side of the reverse, negative n-type contact, as a result of such movement, a glow occurs. It is caused by the release of photons. However, not all photons emit light visible to the human eye. The force that makes the electrons move is called LED current.

This information is of no use to the average person. It is enough to know that the LED has a durable body and contacts, of which there can be from 2 to 4, and also that each LED has its own nominal voltage required for lighting.

Good to know! The connection is always made in the same order. This means that if you connect “+” to the “-” contact on the element, then there will be no glow - p-type materials simply will not be able to charge, which means there will be no movement towards the transition.

Classification of LEDs by their field of application

Such elements can be indicator and lighting. The former were invented before the latter, and they have long been used in radio electronics. But with the advent of the first lighting LED, a real breakthrough in electrical engineering began. Demand lighting this type is growing steadily. But progress does not stand still - new types are being invented and put into production, which become brighter without consuming more energy. Let's look in more detail at what LEDs are.

Indicator LEDs: a little history

The first such red LED was created in the middle of the twentieth century. Although it had low energy efficiency and emitted a dim glow, the direction turned out to be promising and developments in this area continued. In the 70s, green and yellow elements appeared, and work to improve them did not stop. By the year 90, the strength of their luminous flux reaches 1 Lumen.

The year 1993 was marked by the appearance in Japan of the first blue LED, which was much brighter than its predecessors. This meant that now, by combining three colors (which make up all the shades of the rainbow), you can get any color. In the early 2000s, the luminous flux already reached 100 Lumens. Nowadays, LEDs continue to improve, increasing brightness without increasing power consumption.

Use of LEDs in household and industrial lighting

Now such elements are used in all industries, be it machine or automotive manufacturing, lighting of production workshops, streets or apartments. If we take the latest developments, we can say that even the characteristics of LEDs for flashlights are sometimes not inferior to old 220 V halogen lamps. Let's try to give one example. If we take the characteristics of a 3 W LED, they will be comparable to the data of an incandescent lamp with a consumption of 20-25 W. The result is energy savings of almost 10 times, which, with daily constant use in an apartment, provides a very significant benefit.

What are the benefits of LEDs and are there any disadvantages to them?

A lot can be said about the positive qualities of light diodes. The main ones include:

As for negative aspects, then there are only two of them:

• Work only with constant voltage;
• It follows from the first - the high cost of lamps based on them due to the need to use (an electronic stabilizing unit).

What are the main characteristics of LEDs?

When choosing such elements for a particular purpose, everyone pays attention to their technical data. The main things you should pay attention to when purchasing devices based on them:

• consumption current;
• Rated voltage;
• power consumption;
• color temperature;
• luminous flux strength.

This is what we can see on the marking. In fact, there are much more characteristics. Let's talk about them now.

LED current consumption - what is it?

The LED consumption current is 0.02 A. But this only applies to elements with one crystal. There are also more powerful light diodes, which may contain 2, 3 or even 4 crystals. In this case, the current consumption will increase, a multiple of the number of chips. It is this parameter that dictates the need to select a resistor that is soldered at the input. In this case, the LED resistance prevents the high current from instantly burning the LED element. This may happen due to high mains current.

Rated voltage

The voltage of an LED is directly dependent on its color. This happens due to the difference in the materials used to make them. Let's consider this dependence.

Light diode resistance

The same LED itself can have different resistance. It changes depending on its inclusion in the circuit. In one direction - about 1 kOhm, in the other - several MOhms. But there is a nuance here. LED resistance is nonlinear. This means that it can change depending on the voltage applied to it. The higher the voltage, the lower the resistance will be.

Light output and beam angle

The luminous flux angle of LEDs may vary depending on their shape and material of manufacture. It cannot exceed 120 0. For this reason, if greater dispersion is required, special reflectors and lenses are used. This quality of “directional light” contributes to greatest strength luminous flux, which can reach 300-350 lm for one 3 W LED.

LED lamp power

LED power is a purely individual value. It can vary in the range from 0.5 to 3 W. It can be determined using Ohm's law P = I × U , Where I – current strength, and U – LED voltage.

Power – quite important indicator. Especially when it is necessary to calculate what is needed for a particular number of elements.

Colorful temperature

This parameter is similar to other lamps. The temperature spectrum is closest to LED fluorescent lamps. Color temperature is measured in K (Kelvin). The glow can be warm (2700-3000K), neutral (3500-4000K) or cold (5700-7000K). In fact, there are many more shades; the main ones are listed here.

LED element chip size

You won’t be able to measure this parameter yourself when purchasing, and now the dear reader will understand why. The most common sizes are 45x45 mil and 30x30 mil (corresponding to 1 W), 24x40 mil (0.75 W) and 24x24 mil (0.5 W). If we translate into a more familiar measurement system, then 30x30 mil will be equal to 0.762x0.762mm.

There can be many chips (crystals) in one LED. If the element does not have a phosphor layer (RGB - color), then the number of crystals can be counted.

Important! You should not buy very cheap LEDs made in China. They may not only be Low quality, but their characteristics are most often overestimated.

What are SMD LEDs: their characteristics and differences from conventional ones

A clear decoding of this abbreviation looks like Surface Mount Devices, which literally means “surface mounted”. To make it clearer, we can recall that ordinary cylindrical light diodes on legs are recessed into the board and soldered on the other side. In contrast, SMD components are fixed with claws on the same side where they themselves are located. This installation makes it possible to create double-sided printed circuit boards.

Such LEDs are much brighter and more compact than conventional ones and are elements of a new generation. Their dimensions are indicated in the marking. But don't confuse the size SMD LED and a crystal (chip) of which there can be many in the component. Let's look at several of these light diodes.

LED SMD2835 parameters: dimensions and characteristics

Many novice craftsmen confuse the markings SMD2835 with SMD3528. On the one hand, they should be the same, because the marking indicates that these LEDs have sizes of 2.8x3.5 mm and 3.5 by 2.8 mm, which are the same. However, this is a misconception. Specifications The SMD2835 LED is much higher, while it has a thickness of only 0.7 mm versus 2 mm for the SMD3528. Let's look at the SMD2835 data with different powers:

As you can understand, the technical characteristics of SMD2835 can be quite varied. It all depends on the quantity and quality of crystals.

5050 LED Specifications: Larger SMD Component

It is quite surprising that, despite its large dimensions, this LED has a lower luminous flux than the previous version - only 18-20 Lm. The reason for this is the small number of crystals - usually there are only two. The most common application of such elements is in LED strips. The density of the strip is usually 60 pcs/m, which gives a total of about 900 lm/m. Their advantage in this case is that the tape gives a uniform, calm light. In this case, the angle of its illumination is maximum and equal to 120 0.

Such elements are produced with a white glow (cold or warm shade), single-color (red, blue or green), three-color (RGB), as well as four-color (RGBW).

Characteristics of SMD5730 LEDs

Compared to this component, the previous ones are already considered obsolete. They can already be called super bright LEDs. 3 volts, which feed both 5050 and 2835, produce here up to 50 lm at 0.5 watts. The technical characteristics of the SMD5730 are an order of magnitude higher, which means they need to be considered.

Still, this is not the brightest LED of SMD components. Relatively recently, elements appeared on the Russian market that literally outshone all others. We will talk about them now.

Cree LEDs: characteristics and technical data

To date, there are no analogues to Cree products. The characteristics of their super bright LEDs are truly amazing. If previous elements could boast a luminous flux of only 50 Lm from one chip, then, for example, the characteristics of the XHP35 LED from Cree speak of 1300-1500 Lm from one chip. But their power is also greater - it is 13 W.

If we summarize the characteristics of various modifications and models of LEDs of this brand, we can see the following:

The luminous flux strength of the SMD LED "Cree" is called a bin, which is mandatory marked on the packaging. IN Lately There are a lot of counterfeits of this brand, mostly made in China. When purchasing, it is difficult to distinguish them, but after a month of use, their light dims and they cease to differ from others. At a fairly high cost, such an acquisition will be a rather unpleasant surprise.

We offer you a short video on this topic:

Checking an LED with a multimeter - how to do it

The simplest and most accessible way is “dialing”. Multimeters have a separate switch position specifically for diodes. Having switched the device to the desired position, we touch the LED legs with the probes. If the number “1” appears on the display, you should change the polarity. In this position, the multimeter buzzer should sound sound signal, and the LED lights up. If this does not happen, it means it has failed. If the light diode is working properly, but when soldered into the circuit it does not work, there may be two reasons for this - its incorrect location or the failure of the resistor (in modern SMD components it is already built-in, which will become clear during the “dialing” process).

Color coding of light diodes

There is no generally accepted global labeling for such products; each manufacturer designates the color as it suits them. In Russia, color coding of LEDs is used, but few people use it, because the list of elements with letter designations is quite impressive and hardly anyone would want to remember it. Most common letter designation, which many consider generally accepted. But such markings are more often found not on powerful elements, but on LED strips.

Decoding the LED strip marking code

In order to understand how the tape is marked, you need to pay attention to the table:

For example, let's take the specific LED CW SMD5050/60 IP68 marking. From it we can understand what is before us LED Strip Light white for surface mounting. The elements installed on it have a size of 5x5mm, in the amount of 60 pcs/m. The degree of protection allows it to work under water for a long time.

What can you make from LEDs with your own hands?

This is a very interesting question. And if you answer it in detail, it will take a lot of time. The most common use of light diodes is the illumination of pendant and suspended ceilings, a work area in the kitchen or even a computer keyboard.

Expert opinion

ES, EM, EO design engineer (power supply, electrical equipment, interior lighting) ASP North-West LLC

“For the operation of such elements, a power stabilizer or controller is required. You can even take it from an old Chinese garland. Many “craftsmen” write that an ordinary step-down transformer is sufficient, but this is not so. In this case, the diodes will blink.”

Current stabilizer - what function does it perform?

A stabilizer for LEDs is a power source that lowers the voltage and equalizes the current. In other words, it creates conditions for normal operation elements. At the same time, it protects against voltage increases or decreases on the LEDs. There are stabilizers that can not only regulate voltage, ensuring smooth attenuation of light elements, but also control color or flicker modes. They are called controllers. Similar devices can be seen on garlands. They are also sold in electrical stores for switching with RGB strips. Such controllers are equipped with remote controls.

The circuit of such a device is not complicated, and if desired the simplest stabilizer You can also make it yourself. To do this, you only need a little knowledge in radio electronics and the ability to hold a soldering iron.

Daytime running lights for a car

The use of light diodes in the automotive industry is quite common. For example, DRLs are manufactured exclusively with their help. But if the car is not equipped with running lights, then purchasing them can hit your pocket. Many car enthusiasts make do with a cheap LED strip, but this is not a very good idea. Especially if the strength of its luminous flux is low. A good solution might be to purchase self-adhesive tape with Cree diodes.

It is quite possible to make DRLs using already broken ones by placing new, powerful diodes inside the old cases.

Important! Daytime running lights are designed specifically to make the car visible during the day and not at night. There is no point in checking how they will shine in the dark. DRLs should be visible in the sun.

Flashing LEDs - what is this for?

A good option for using such elements would be an advertising board. But if it glows statically, it will not attract the attention it deserves. The main task is to assemble and solder the shield - this requires some skills, which are not difficult to acquire. After assembly, you can mount a controller from the same garland. The result is a flashing advertisement that will clearly attract attention.

Color music using light diodes - is it difficult to make?

This job is no longer for beginners. In order to assemble a full-fledged color music with your own hands, you need not only an accurate calculation of the elements, but also knowledge of radio electronics. But still, its simplest version is within the capabilities of everyone.

You can always find a sound sensor in radio electronics stores, and many modern switches have one (light when clapping). If you have an LED strip and a stabilizer, then by running “+” from the power supply to the strip through a similar firecracker, you can achieve the desired result.

Voltage indicator: what to do if it burns out

Modern indicator screwdrivers They consist precisely of a light diode and resistances with an insulator. Most often this is an ebonite insert. If the element inside burns out, it can be replaced with a new one. And the craftsman himself will choose the color.

Another option is to make a chain tester. To do this you will need 2 AA batteries, wires and a light diode. Having connected the batteries in series, we solder one of the legs of the element to the positive of the battery. The wires will come from the other leg and from the battery negative. As a result, when shorted, the diode will light up (if the polarity is not reversed).

LED connection diagrams - how to do everything correctly

Such elements can be connected in two ways - in series and in parallel. At the same time, we must not forget that the light diode must be positioned correctly. Otherwise, the scheme will not work. IN ordinary elements with a cylindrical shape, this can be determined as follows: a flag is visible on the cathode (-), it is slightly larger than the anode (+).

How to calculate LED resistance

Calculating the resistance of a light diode is very important. Otherwise, the element will simply burn out, unable to withstand the magnitude of the network current.

This can be done using the formula:

R = (VS – VL) / I, Where

• VS - supply voltage;
• VL – rated voltage for LED;
• I – LED current (usually 0.02 A, which is equal to 20 mA).

Anything is possible if desired. The circuit is quite simple - we use a power supply from a broken mobile phone or any other. The main thing is that it has a rectifier. It is important not to overdo it with the load (with the number of diodes), otherwise there is a risk of burning the power supply. Standard Charger will withstand 6-12 elements. You can mount a colored backlight for a computer keyboard by taking 2 blue, white, red, green and yellow elements. It turns out quite beautiful.

Helpful information! The voltage supplied by the power supply is 3.7 V. This means that the diodes need to be connected in series-connected pairs in parallel.

Parallel and serial connection: how they are performed

According to the laws of physics and electrical engineering when parallel connection the voltage is distributed evenly across all consumers, remaining unchanged at each of them. With sequential installation, the flow is divided and at each of the consumers it becomes a multiple of their number. In other words, if you take 8 light diodes connected in series, they will work normally on 12 V. If they are connected in parallel, they will burn out.

Connecting 12 V light diodes as the best option

Any LED strip is designed to be connected to a stabilizer that produces 12 or 24 V. Today on the shelves Russian stores a huge range of products available various manufacturers with these parameters. But still, 12 V tapes and controllers predominate. This voltage is safer for humans, and the cost of such devices is lower. ABOUT self-connection to the 12 V network was mentioned a little higher, but there shouldn’t be any problems with connecting to the controller - they come with a diagram that even a schoolboy can figure out.

Finally

The popularity that light diodes are gaining cannot but rejoice. After all, this makes progress move forward. And who knows, maybe in the near future new LEDs will appear that will have an order of magnitude higher performance than those currently existing.

We hope our article was useful to our dear reader. If you have any questions on the topic, please ask them in the discussions. Our team is always ready to answer them. Write, share your experience, because it can help someone.

Video: how to properly connect an LED

Understanding what parameters the operation of a flashlight depends on is equally important for those who want to choose a ready-made model and those who want to design a device with their own hands (be it a keychain flashlight with an LED, a pocket, head-mounted or hiking version). Repairing flashlights mainly depends on their design, and replacing some elements requires special skills. Bright is not the only definition for a quality device.

The first step is to identify the purpose of the flashlight. It is hardly possible to highlight universal device, equally effective in any conditions. After all, small pocket flashlight will never compare with powerful stationary equipment, and homemade devices are far from always superior to ready-made ones (even those made in China), and the point is not only in how the LED was selected.

Dimensions

It is necessary to determine the size of the flashlight in 2 cases: to be able to carry it with you (in your pocket, bag, etc.), and to correctly calculate the body when drawing up the diagram yourself.

Dimensions also need to be known when selecting accessories. A headlamp is worn on a special tape, and a hiking lamp is worn on a clip or in a fabric case (on the belt).

Luminous flux parameters

Often, the brightest flashlight is required, but a large number of lumens does not always completely determine this indicator. An equally important role is played by the lighting dispersion angle. A simple keychain flashlight with an LED or any pocket version can handle illumination of a small area. The narrower the beam, the further a device can shine, for example, a headlamp for hiking.

Important: The lens can radically change the characteristics of the device. The operation scheme of focusable flashlights is quite simple: the position of the lens adjusts the width and tilt of the beam as it approaches/moves away from the LED.
Selection of the LED itself

It is the light source that determines most of the flashlight's performance (how bright it is). The operation of the device is affected not only by the LED itself, but also by the value of its operating current. The current strength must be taken into account so as not to inadvertently burn the device, because repairing the flashlight is not always appropriate. LEDs and their strings can be grouped in different ways to increase range or coverage area (the largest is usually located closer to the center).

Work offline

Duration of work is a very relative value. It is determined not only by the choice of battery, but also by the flashlight mode, for which the LED is responsible. As for homemade devices, and for ready-made ones, you can install a timer to save energy. Offline mode can be counted in hours (pocket and headlamp) and even days (emergency and search), this period is influenced mainly by the main characteristics.

Types of batteries

Batteries vary depending on the principle of energy generation; among the most popular types are the following:

• lithium (Li-Ion);
• nickel metal hydride (NiMH);
• nickel-cadmium (NiCd);
• lead-acid;
• lithium polymer (Li‑pol);
• nickel-zinc (NiZn).

A small flashlight (pocket or headlamp) can also work on regular AA batteries, in other cases, it is better to select the battery type based on general requirements so that repairing or replacing the battery does not become an impossible task.

Operating modes

The simpler the device, the fewer modes it has in its arsenal. The simplest bright keychain flashlight with an LED, pocket and headlamps, as a rule, have no more than one. How more complex system– the greater the probability of failure of one of the components, i.e. the more often they require repairs.

Classification of modes:

• brightness (minimum-medium-maximum);
• signal (strobe);
• programmable (manually configured by the user).

Exposure to external factors

The circuit itself and the LED must be protected from shock, shaking, dust and dirt. For more serious devices, it is better to ensure moisture resistance. This can be quite difficult not only when self-assembly, but also after purchasing ready-made models. It is better to check the water resistance in advance, especially on Chinese-made flashlights, in order to be able to carry out repairs in a timely manner.

Mounting location

The flashlight should be easy to use. To do this, you need to think in advance about how the circuit will be drawn up - the location of the buttons responsible for how the LED, auxiliary lenses and diffusers work. It is important to be able to adjust the mount (headlamp or bicycle light), clamping density, etc.

Current stabilization

The operating mode of an LED flashlight directly depends on the supplied current; other characteristics may be similar. Stabilized devices are considered brighter and more stable, but when discharged they quickly go out. An unstabilized flashlight is less bright, but the lamps go out gradually, eventually reducing their brightness to 0.

Having understood the parameters of the device, it becomes much easier not only to select the type of flashlight you are interested in (pocket, head, mounted, keychain flashlight with LED), but also to determine the required elements, if you have your own circuit and selected the appropriate LED, as well as to carry out partial repairs of the device .