What do the characteristics of LED flashlights mean in simple terms? LEDs for flashlights: characteristics, photos, diagrams Which LED is needed for a flashlight

The American company CREE is a leading manufacturer of solid-state light sources. The LEDs of the XLamp family of the XR, XP, MC series developed and produced by it are highly efficient and economical, which makes it possible to create modern technologically advanced and environmentally friendly lighting devices on their basis.

So let's decipher the notation a little.

For example, the flashlight says: LED CREE XP-E R2

CREE is naturally the name of the diode manufacturer

XR-E, CREE has XP-E, XP-G, other companies have P4, P7, etc. - this is the designation of the diode itself.

R2 - brightness bin. Bin shows how many lumens the LED produces when consuming 1 watt of energy, for an LED this is a current of 350 mA. In English this parameter is called flux bin. Currently there are Q2, Q3, Q4, Q5, R2, R3, R4, R5, S2. The table below shows how many lumens can be obtained from which diode.

Q2-Q5 and R2 are available for XR-E diodes, R2, R3 are available for XP-E, R4-R5 and S2 are only available for XP-G.

What is the main difference other than brightness?

XR-E is the oldest and is found only in flashlight models that have been on the market for quite some time. XR-E is externally very easy to identify, it has a large hemisphere covered by a diode, the crystal itself is larger than that of subsequent series (for comparison, on the XP series it is just a droplet, the size of the XP-E compared to the XR-E was reduced by 80%. XP -E differs from XP-G in that the E has three stripes on the diode, the G series has four, it turns out that the area of ​​the XP-G is larger.

Consequently, in reflectors of the same size and structure, the longest-range one is XP-E, since it has the smallest crystal, and the smallest light source, since it is easy to focus into a narrow beam, then XR-E, and the widest beam is XP-G, not because of the crystal size, but because of the difficulty of focusing, more on that below.

If the diodes are arranged according to energy efficiency from weakest to brightest, we get XR-E - XP-E - XP-G, where the latter is the most energy efficient, see the table below.

It would seem that if there is the brightest and newest and most efficient XP-G diode, then why are all the well-known and respected flashlight manufacturers in no hurry to switch to this diode. The reason is simple. Each diode requires a specially designed reflector to produce an acceptable light beam.

Let's look at all the series. If you shine a flashlight on a flat wall, you will see the following artifacts:

U XP-E- an ideal picture without any flaws: a well and evenly focused central beam and smooth side illumination without dips.

U XP-G When focusing using a reflector, a so-called donut hole can be observed, when the central beam of light looks like a donut with a noticeable darkening inside. This is not the fault of the flashlight manufacturers, but a feature of the diode. Therefore, companies such as Fenix, Jetbeam, Nitecore, Zebra, 4sevens were in no hurry to update their lineup, while others, in the race for new products, either installed a highly textured reflector, or simply used reflectors for other types of diodes. All this negatively affects the focusing of the beam and the range of the flashlights. According to many experts, flashlights using this type of diode are inferior in range to older models using XP-E and XR-E.

XM-L- is a real masterpiece of this company! This is the latest development of 2011! Since the invention of this LED, 95% of powerful flashlights are built on it! This diode has outstanding characteristics. Its brightness reaches up to 1000 lumens at a current of 3A!

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 identify a universal device that is equally effective in all conditions. In the end, a small pocket flashlight can never compare with powerful stationary equipment, and homemade devices are not always superior to ready-made ones (even those made in China), and it’s not just 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 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. For both homemade devices and ready-made ones, you can install a timer to save energy. Autonomous mode can last for hours (pocket and headlamps) 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 operate on ordinary AA batteries; in other cases, it is better to select the type of battery based on general requirements so that repairing or replacing the battery does not become an unsolvable 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. The more complex the 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 assembling it yourself, 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 the 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 .

The use of LEDs in flashlights has long passed from fashion trends to a theoretically and practically justified necessity. They, unlike incandescent lamps, are designed for use in directional light sources.

Numerous features of the light-emitting matrix of diodes make it possible to obtain devices with parameters that are even theoretically impossible for an incandescent lamp to approach.

The most powerful flashlights in the world

The most powerful tactical flashlight in the world was created by the Korean company Polarion based on a xenon lamp. Two models are available: PH50 and PF50 (with and without handle).

Initially, a heavy-duty tactical flashlight was produced for special services and special forces. It is now available for purchase. The average price is $1100. Let's go through its characteristics.

• Luminous flux 5200 lumens;
• beam range 1500 meters;
• weight - 1.8 kg;
• ignition time to maximum brightness - 4 seconds;
• operating time 90 minutes;
• Battery charging time from a 220V network is 4 hours.

But in fact this is far from the limit.

A homemade LED flashlight with a luminous flux power of 18,000 lumens was manufactured in Germany (Frankfurt)! It is so bright that it can easily burn out the retina of the eye.

Types of Powerful LED Flashlights

There are about 10 types of lanterns depending on their purpose:

• Hand-held compact or full-size flashlights. Classic form factor, suitable for everyday household needs.
• Headlamps. Allows you to illuminate your workspace while leaving your hands free.
• Highly specialized flashlights. These include underwater flashlights, shock-resistant tourist flashlights, laser flashlights, tactical flashlights (under-barrel flashlights), etc.
• Flashlight shocker. Performs a protective role. It is equipped with a powerful battery and produces an arc voltage of up to 3,000,000 Volts.

We will be looking at hand-held, full-size, high-power flashlights. They can be divided into two types, depending on their purpose: signaling and lighting.

Signal lights designed to create a narrow beam of light that maintains focus over long distances.

This type produces a spot of high brightness even at a distance of 600-800 meters.

In lighting lanterns reflectors of scattering type. They provide bright illumination with a beam angle of approximately 120 degrees.

How to choose an LED flashlight

Let's look at what to look for when choosing a powerful LED flashlight.

Luminous flux power: from 60 lumens to 4600 lumens. The larger it is, the brighter it is and the faster the battery will drain.

Based on the intensity of the light flux, you can estimate how far it will shine. Determine the distance using the table below.

Power supply type:

• batteries;
• batteries;
• combined (batteries with built-in generator).

We choose according to our needs. The rechargeable one is more expensive, but with regular use we benefit from charging. Battery-powered ones are cheaper, but if you choose a powerful LED, you will buy them weekly.

The type of power source determines its operating time. Essentially, the more the better, but also much more expensive. Choose by finance. The average battery capacity, depending on its type, is shown in the table below. Depending on the capacity, you can calculate how long the LED flashlight will work (see below for how to calculate).

Focus type:

• signal (search);
• lighting.

The light of a signal light is focused into a thin beam, allowing it to shine much further than conventional flashlights. But apart from the beam spot, nothing will be visible around.

Flashlights are more defocused, making them more convenient to use at home, on a bicycle, hunting, etc.

How to choose a household LED flashlight

For domestic needs, high power is not needed. A more important parameter is the battery life.

If you plan to use the flashlight regularly, it is better to consider battery-powered models with a built-in generator. The built-in generator will not allow you to be left without lighting. It works on the principle of a dynamo; for domestic needs this is the optimal, almost eternal option.

How to choose a powerful rechargeable LED flashlight

Powerful LED flashlights are purchased by those who are interested in fishing, hunting, or often spend the night outdoors.

First of all, we look at the type of housing protection:

• IP50 protection class provides protection against dirt and dust;
• protection class IP65 - products that are not afraid of moisture, and with the IP67-69 marking you can even be submerged under water.

Choose the power of LEDs and batteries for a household flashlight based on your needs. Recommendations are provided above.

How to calculate the operating time of a flashlight using batteries or rechargeable batteries

The LED crystal supply voltage is 3.2-3.4V. Average current consumption is 300mA per 100 lumens.

When powering a weak flashlight with a brightness of 50 lumens, from 2 AA batteries with a total capacity of 4000 mAh, they will be enough for 26 hours of continuous operation of the flashlight. Taking into account the error in current consumption and battery capacity, we will add a correction factor of 0.8. Total 21 hours.

Operating time = 4000mAh(capacity of our batteries) / 150 mA(LED current consumption) * 0.8 = about 21 hours.

The capacity can be found on the batteries themselves or in the flashlight passport (if it is rechargeable). We take the current consumption based on the luminous flux of the installed LED (it is in the flashlight passport or can be found by the marking of the LED matrix).

With a luminous flux of a super powerful flashlight of 1000Lm, the consumption will be 3000mA. We divide the capacity of 4000 by the consumption of 3000 with a coefficient of 0.8 = we get the period of continuous operation from the same 2 AA batteries in 1 hour.

How to convert an ordinary flashlight into an LED one

The price of powerful flashlights is from 20 to 500 dollars. At the same time, for a couple of dollars you can buy an ordinary flashlight with a high-quality body, which, with minimal investment, will turn into a powerful light source using diodes.

Which LED is best for a flashlight? The LED used must be rated for voltages up to 5 volts and have a compact size.

The brightest LED for a flashlight

If you want to build a very powerful flashlight with minimal investment, pay attention to a model such as Luminus SST-90-WW Star 30W. Its supply voltage is 3-3.7 volts, which will make the flashlight quite compact.

The luminous flux at a current consumption of 9000 mA is 2300 lumens. It is clear that it will not be able to work normally from AA batteries, much less from ordinary batteries.

To make such a flashlight, it is better to use a massive housing in which one or two 6-volt, 6Ah batteries can be installed.

To cool the matrix you will need a massive heatsink and a power driver.

A conversion in this version costs $35-40, but ready-made solutions of similar power start from $100-120.

When creating a similar design using three bright LEDs for a Cree XM-L2 T6 10W flashlight, the design will cost almost half as much, due to the price of the drivers and the diodes themselves.

Homemade bright flashlight

Choose a compact diode with a power of up to 1W for your flashlight. Diode supply voltage 3.2-3.6 V, current consumption 300 mA, luminous flux 100 lumens. The relatively low power will allow you to do without a cooling radiator.

With a light emitter size of 25 x 25 mm, it is possible to install 9 such LEDs with a total brightness of 900 lumens. It is possible to use a budget current stabilizer LM317 () as a driver. With a total current consumption of up to 2700 mA, this flashlight can be powered from two AA batteries.

The total cost of refurbishment will not exceed ten dollars.

When choosing 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 a more complex 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 Cree company, which produces a wide line of 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 the one-watt version, the forward 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 radiation intensity, 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 a warm white emission color (T≤3500°K) are the 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 the operating temperature to increase 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 their 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 must not only be ergonomic, but also be 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.

A division of the Japanese company Nichia has long 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 the world-famous company Cree hold the lead not only on the American continent. Standing out due to their 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 producing LED backlights for its 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 has relied on the introduction of 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 in the visible spectrum, but also make discoveries in the IR, UV and laser directions.

Scientific reports coupled with news about the development of artificial lighting indicate continued healthy competition between large corporations. We see positive trends in the development of LED technology in the constantly updated range of flashlights, surprising with their long-range beam, high degree of protection, ability to charge from solar energy and other know-how.

Read also

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, from the first indicator element to the brightest “Cree” diode to date, was preceded by a huge amount of work. Today we will try to analyze the various characteristics of LEDs, find out how these elements have evolved and how they are classified.

Read in the article:

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. The demand for lighting devices of this type is steadily growing. 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 the negative aspects, 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 can 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 angle of the luminous flux 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 the greatest 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 is a fairly 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 closest temperature spectrum to LED fluorescent lamps is. 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 of poor quality, but their characteristics are most often overstated.

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 do not confuse the size of the SMD LED and the 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 thing. However, this is a misconception. The technical characteristics of the SMD2835 LED are 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 SMD LED “Cree” is called a bin, which is mandatory to be marked on the packaging. Recently, a lot of counterfeits of this brand have appeared, 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's buzzer should beep and the LED should light 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 worldwide marking 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. The 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 you can understand that this is a white LED strip 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 to illuminate suspended 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 the normal operation of 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 design of such a device is not complicated, and if desired, a simple stabilizer can be made with your own hands. 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 consist of a light diode and resistors 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 cells 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. A standard charger will handle 6-12 cells. 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, with a 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 of Russian stores there is a huge assortment of products from 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. Self-connection to a 12 V network was discussed a little higher, but there shouldn’t be any problems with connecting to the controller - they come with a diagram that even a schoolchild 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