The most powerful diode for a flashlight. Characteristics of LEDs: main parameters and distinctive features

The problem of choosing an LED is acute due to their wide range and unlimited price range. The production technology and parameters of LED lamps are accelerating very quickly. It is difficult to keep up with new products, it is even more difficult to figure out which diode is better, which is newer and what should be bought in this or that case.

Of course, you should choose a light source based on your needs. If you are a fanatic of novelties and like to measure the length and width of the beam in the company of like-minded people, naturally, you need the latest super-bright novelties. For hunters, fishermen, divers and other lovers of active pastime, the brightness, focusing or scattering of the beam, its color shade are important.

Deciphering the bin codes of LEDs

In the production of LEDs, they are assigned bin codes. At first glance, this abracadabra does not mean anything. Only knowing the classification, it becomes completely clear which diode is in front of you. The LED bin includes data on the housing design, color subgroup, color shade, brightness code. There are additional digits related to the internal production code, for the user they have no value.

For example:
XPGWHT-L1-1C0-R5 is a diode with XPG package, color - WHT (white), subgroup L1 - white, 1C0 - shade according to ANSI table, R5 - brightness code (139-148 lumens at 350 mA).

Cree XLAMP XR-E

A common, but rather outdated LED. It is a small crystal with a protective glass lens mounted on a substrate that acts as a heat sink and serves as the basis for contacts.

The light output depends on the brightness code and ranges from Q2 (87.4 to 93.9 lumens) to R2 (114 to 122 lumens) at 350 mA. As a rule, a diode of this class is used in inexpensive flashlights. The maximum temperature of the light-emitting crystal is up to 150 °C, when operating with a maximum current of not more than 1 A and a voltage of not more than 3.9 V.

Available in colors:
warm white - 2700-3600°K;
neutral white - 3700-5000°K;
cold white -5000-10000°K.

Cree XLAMP XP

• XPE. This series is particularly popular due to the combination of robust design, high light output and acceptable cost. Externally, the crystal has big sizes than the previous series, the reflector is shallow. Maximum temperature 150 °C, current 1 A, voltage 3.4 V. Cree XPE has a wider temperature scale of colors, the “Outdoor white” shade has been introduced into the scale with a range of 4000-5300 °K. It's more natural cold White color. Luminance bins: N4, P2, P3, P4, Q2, Q3, Q4, Q5, R2, R3, these are 144-280 lm. Luminous efficiency 19-34 lm/W.
• XPC. This series is a modification of XP-E with a current of 0.5 A and a voltage of 3.5 V. Color shades and luminous flux power are in the same range as that of the prototype. The light output is higher (35-59 lm / W), respectively, we can talk about a clear advantage in this parameter. XPE and XPC are used in small handheld flashlights.
• XPG. New generation LED with superbrightness and efficiency. Has relatively large area crystal, can withstand up to 1.5 A. Light output leaves far behind its predecessors and is in the range from 90 to 139 lm / W. Maximum luminous flux 346-534 Lm. The color shade is divided into 4 groups. Luminance bin classification: Q4, Q5, R2, R3, R4, R5, S2, S3 - determined at a current of 700 mA. Diodes of this class are used for powerful handheld, sporting flashlights. For long-range, super-bright flashlights, the latest XP-G2 system should be used, which has more light output at standard characteristics.

Cree XM-L

Very powerful LED (10 W) used in professional flashlights and stationary lighting sources. The crystal is 2.5 times larger than XPG, which provides a wide beam of light. If you use a shallow reflector, you get a large jellied spot from the lantern. The luminous flux at a current of 3 A can reach 900 lm. The maximum luminous flux depending on the brightness bin is 1008 lm. The classification of brightness bins is determined at a current of 700 mA, the following are used: S6, T2-T6, U2, U3 (similar to Cree J-A5).

Which diode to choose?

If lighting characteristics are important to you, then you don’t have to look at the brand of the LED, since it determines only design features. There is no need to buy a powerful Cree XM-L diode for a key fob flashlight, XPE is enough here. For powerful and reliable light sources, XP-G, XP-G2, XM-L, XM-L2 are better suited.

The color group is a matter of taste. The best options are neutral or natural white. The exception is professionals who use LEDs in their optics and the spectral shade is important to them.

The power of the flashlight depends on the power source, but the brightness directly on the bins. At a current of 350 mA, Q5 and R2 will be the brightest, at a current of 700 mA - T6, S3 or U2, U3. When choosing brightness bins, keep in mind that some of them, for example, U, can only work in the cold spectrum, so for flashlights with soft, warm light, it is better to choose something of their T encoding.

Let's take a look at LED products ranging from the old 5mm LEDs to super-bright high-power LEDs up to 10W.

To choose the “right” flashlight for your needs, you need to understand what kind of LED flashlights are and their characteristics.

What diodes are used in flashlights?

Powerful LED lights began with devices with a 5mm matrix.

LED flashlights in completely different designs, from pocket to camping, became widespread in the mid-2000s. Their price has dropped significantly, and the brightness and long battery life have played a role.

5mm white ultra-bright LEDs draw 20 to 50 mA of current at a voltage drop of 3.2-3.4 volts. Light intensity - 800 mcd.

They show themselves very well in miniature flashlights-trinkets. The small size allows you to carry such a flashlight with you. They are powered either by "mini-finger" batteries, or from several round "pills". Often used in lighters with a flashlight.

These are the LEDs that have been installed in Chinese lanterns for many years, but their age is gradually expiring.

In search lights with a large reflector, it is possible to mount dozens of such diodes, but such solutions are gradually fading into the background, and the choice of buyers falls in favor of lights on powerful Cree-type LEDs.

These flashlights run on AA, AAA or rechargeable batteries. They are inexpensive and lose both in brightness and quality to modern flashlights on more powerful crystals, but more on that below.

AT further development flashlight manufacturers have gone through many options, but the market for quality products is occupied by flashlights with powerful matrices or discrete LEDs.

What LEDs are used in powerful flashlights?

Powerful lanterns mean modern lanterns various types ranging from those that are the size of a finger, ending with huge search lights.

In such products in 2017, the Cree brand is relevant. This is the name of an American company. Its products are considered one of the most advanced in the field of LED technology. An alternative are LEDs from the manufacturer Luminus.

Such things are far superior to LEDs from Chinese lanterns.

What are the most commonly installed Cree LEDs in flashlights?

Models are named consisting of three to four characters separated by a hyphen. So diodes Cree XR-E, XR-G, XM-L, XP-E. Models XP-E2, G2 are most often used for small flashlights, while XM-L and L2 are very versatile.

They are used starting from the so-called. EDC flashlights (everyday wear) are from small flashlights smaller than the palm of your hand, to serious large search lights.

Let's look at the characteristics of high-power LEDs for flashlights.

Name	Cree XM-L T6	Cree XM-L2	Cree XP-G2	Cree XR-E
A photo
U, V	2,9	2,85	2,8	3,3
I, mA	700	700	350	350
P, W	2	2	1	1
Operating temperature, °C
Luminous flux, Lm	280	320	145	100
Luminescence angle, °	125	125	115	90
Color rendering index, Ra	80-90	70-90	80-90	70-90

The main characteristic of LEDs for flashlights is the luminous flux. It determines the brightness of your flashlight and the amount of light that the source can give. Different LEDs, consuming the same amount of energy, can differ significantly in brightness.

Consider the characteristics of LEDs in large flashlights, searchlight type :

Name
A photo
U, V	5,7; 8,55; 34,2;	6; 12;	3,6	3,5
I, mA	1100; 735; 185;	2500; 1250	5000	9000...13500
P, W	6,3	8,5	18	20...40
Operating temperature, °C
Luminous flux, Lm	440	510	1250	2000...2500
Luminescence angle, °	115	120	100	90
Color rendering index, Ra		70-90	80-90	80-90

Sellers often indicate not the full name of the diode, its type and characteristics, but an abbreviated, slightly different alphanumeric marking:

• For XM-L: T5; T6; U2;
• XP-G: R4; R5; S2;
• XP-E: Q5; R2; R;
• for XR-E: P4; Q3; Q5; R.

The lantern can be called just that, “EDC T6 Lantern”, information in such brevity is more than enough.

Flashlight repair

Unfortunately, the price of such flashlights is quite high, as well as the diodes themselves. And it is not always possible to purchase a new flashlight in case of breakage. Let's figure out how to change the LED in the flashlight.

To repair a flashlight, you need a minimum set of tools:

• soldering iron;
• flux;
• solder;
• screwdriver;
• multimeter.

To get to the light source, you need to unscrew the head of the lantern, it is usually fixed on a threaded connection.

In diode test or resistance measurement mode, check if the LED is working properly. To do this, touch the black and red probes to the LED leads, first in one position, and then swap red and black.

If the diode is working, then in one of the positions there will be low resistance, and in the other - high. This way you determine that the diode is good and conducts current in only one direction. During the test, the diode may emit a weak light.

Otherwise, there will be a short circuit or high resistance (open) in both positions. Then you need to replace the diode in the lamp.

Now you need to unsolder the LED from the lamp and, observing the polarity, solder a new one. Be careful when choosing an LED, consider its current consumption and voltage for which it is designed.

If you neglect these parameters - at best, the flashlight will quickly sit down, at worst - the driver will fail.

A driver is a device for powering an LED with a stabilized current from various sources. Drivers are manufactured industrially for power supply from a 220 volt network, from a car electrical network - 12-14.7 volts, from Li-ion batteries, for example, size 18650. Most powerful flashlights are equipped with a driver.

Increasing the power of the flashlight

If you are not satisfied with the brightness of your flashlight or you figured out how to replace the LED in the flashlight and want to upgrade it, before buying heavy-duty models, study the basic principles of LED operation and limitations in their operation.

Diode matrices do not like overheating - this is the main postulate! And replacing the LED in the flashlight with a more powerful one can lead to such a situation. Pay attention to the models in which more powerful diodes are installed and compare with yours, if they are similar in size and design, change them.

If your flashlight is smaller, additional cooling will be required. We wrote more about making radiators with our own hands.

If you try to install such a giant as the Cree MK-R in a miniature keychain flashlight, it will quickly fail from overheating and it will be a waste of money. A slight increase in power (by a couple of watts) is acceptable without upgrading the flashlight itself.

Otherwise, the process of replacing the brand of LED in a flashlight with a more powerful one is described above.

Lanterns Police

Such flashlights shine brightly and can act as a means of self-defense. However, they also have problems with LEDs.

How to replace the LED in a Police flashlight

A wide range of models is very difficult to cover in one article, but general repair recommendations can be given.

1. When repairing a flashlight with a stun gun, be careful, it is advisable to use rubber gloves to avoid electric shock.
2. Lanterns with dust and moisture protection are assembled on a large number of screws. They differ in length, so make notes where you unscrewed one or another screw.
3. The optical system of the Police flashlight allows you to adjust the diameter of the light spot. When disassembling on the body, make marks in what position the parts were before removal, otherwise it will be difficult to put the block with the lens back.

Replacing the LED, voltage converter unit, driver, battery is possible using a standard soldering kit.

What LEDs are in Chinese lanterns?

Many products are now bought on aliexpress, where you can find both original products and Chinese copies that do not match the stated description. The price for such devices is comparable to the price of the original.

In a flashlight where the Cree LED is declared, it may not actually be there, at best there will be a frankly different type of diode, at worst one that will be difficult to distinguish from the original outwardly.

What might this entail? Cheap LEDs are made in low-tech conditions and do not give out the declared power. They have a low efficiency, from which they have increased heating of the case and crystal. As already mentioned, overheating is the worst enemy for LED devices.

This happens because when the semiconductor is heated, the current increases, as a result of which the heating becomes even stronger, the power is released even more, this leads to an avalanche-like breakdown or breakage of the LED.

If you try and spend time searching for information, you can determine the originality of products.

LatticeBright is a Chinese LED manufacturer that makes products very similar to Cree, probably a design match (sarcasm).

On the substrates, these clones look like this. You can see the variety of shapes of LED substrates produced in China.

Fakes are quite skillfully made, many sellers do not indicate this "brand" in the product description and where the LEDs for the lights are made. The quality of such diodes is not the worst among Chinese junk, but far from the original.

Installing an LED instead of an incandescent lamp

Many old things have horse races or lanterns on an incandescent lamp gathering dust and you can easily make it LED. For this there is either turnkey solutions, or self-made.

With a broken light bulb and LEDs, with a little ingenuity and solder, you can make a great replacement.

An iron barrel in this case is needed to improve heat dissipation from the LED. Next, you need to solder all the parts to each other and fix with glue.

When assembling, be careful - avoid shorting the leads, hot glue or heat shrink tubing will help with this. The central contact of the lamp must be soldered - a hole is formed. Pass a resistor lead through it.

Next, you need to solder the free output of the LED to the base, and the resistor to the central contact. For a voltage of 12 volts, you need a 500 Ohm resistor, and for a voltage of 5 V - 50-100 Ohms, for power from a Li-ion 3.7V battery - 10-25 Ohms.

Choosing an LED for a flashlight is much more difficult than replacing it. It is necessary to take into account a lot of parameters: from brightness and scattering angle, to case heating.

In addition, we must not forget about the power supply for the diodes. If you master everything described above, your devices will shine for a long time and with high quality!

We make a flashlight on LEDs with our own hands

LED flashlight with 3V converter for LED 0.3-1.5V 0.3-1.5 VLEDflash light

Usually, a blue or white LED requires 3 - 3.5v to operate, this circuit allows you to power a blue or white LED with low voltage from a single AA battery.Normally, if you want to light up a blue or white LED you need to provide it with 3 - 3.5 V, like from a 3 V lithium coin cell.

Details:
Light-emitting diode
Ferrite ring (~10 mm diameter)
Winding wire (20 cm)
1kΩ resistor
N-P-N transistor
Battery




Parameters of the used transformer:
The winding going to the LED has ~45 turns wound with 0.25mm wire.
The winding going to the base of the transistor has ~30 turns of 0.1mm wire.
The base resistor in this case has a resistance of about 2K.
Instead of R1, it is desirable to put a tuning resistor, and achieve a current through the diode ~ 22mA, with a fresh battery, measure its resistance, then replacing it with a constant resistor of the received value.

The assembled circuit must work immediately.
There are only 2 reasons why the scheme will not work.
1. the ends of the winding are mixed up.
2. too few turns of the base winding.
Generation disappears, with the number of turns<15.



Put the pieces of wire together and wind around the ring.
Connect the two ends of different wires together.
The circuit can be placed inside a suitable enclosure.
The introduction of such a circuit into a flashlight operating from 3V significantly extends the duration of its operation from one set of batteries.

Here you can see what the results of the experiment led to.

The circuit offered to your attention was used to power an LED flashlight, recharge a mobile phone from two metal hydrite batteries, when creating a microcontroller device, a radio microphone. In each case, the operation of the circuit was flawless. The list where you can use the MAX1674 can be continued for a long time.


The easiest way to get a more or less stable current through the LED is to connect it to the unregulated power circuit through a resistor. Keep in mind that the supply voltage must be at least twice the operating voltage of the LED. The current through the LED is calculated by the formula:
I led \u003d (Umax. supply - U working diode) : R1

This scheme is extremely simple and in many cases justified, but it should be used where there is no need to save electricity, and there are no high requirements for reliability.
More stable circuits - based on linear stabilizers:


As stabilizers, it is better to choose adjustable, or fixed voltage, but it should be as close as possible to the voltage on the LED or a string of LEDs connected in series.
Stabilizers like LM 317 are very suitable.
German text: iel war es, mit nur einer NiCd-Zelle (AAA, 250mAh) eine der neuen ultrahellen LEDs mit 5600mCd zu betreiben. Diese LEDs benötigen 3,6V/20mA. Ich habe Ihre Schaltung zunächst unverändert übernommen, als Induktivität hatte ich allerdings nur eine mit 1,4mH zur Hand. Die Schaltung lief auf Anhieb! Allerdings ließ die Leuchtstärke doch noch zu wünschen übrig. Mehr zufällig stellte ich fest, dass die LED extrem heller wurde, wenn ich ein Spannungsmessgerät parallel zur LED schaltete!??? Tatsächlich waren es nur die Messschnüre, bzw. deren Kapazität, die den Effekt bewirkten. Mit einem Oszilloskop konnte ich dann feststellen, dass in dem Moment die Frequenz stark anstieg. Hm, also habe ich den 100nF-Condensator gegen einen 4.7nF Typ ausgetauscht und schon war die Helligkeit wie gewünscht. Anschließend habe ich dann nur noch durch Ausprobieren die beste Spule aus meiner Sammlung gesucht... Das beste Ergebnis hatte ich mit einem alten Sperrkreis für den 19KHz Pilotton (UKW), aus dem ich die Kreiskapazität entfernt habe. Und hier ist sie nun, die Mini-Taschenlampe:

Sources:
http://pro-radio.ru/
http://radiokot.ru/

LEDs are based on semiconductor knowledge and practice. They have been known to mankind for almost half a century. At the same time, all the starting materials for the manufacture of such lighting devices have been known for more than 20 years. Nevertheless, it was only recently possible to connect them correctly and obtain impressive LED characteristics. This lighting represents an innovative breakthrough, thanks to which diodes have become 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 the 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 the following characteristics of LEDs:

1. Luminous flux. This parameter is measured in lumens (Lm) and indicates the amount of light that the lamp gives out. The higher this indicator, the brighter it will shine.
2. Power consumption, measured in Watts (W). The smaller this parameter, the more economical the power consumption.
3. Light output, its unit of measurement is Lm / W. It is central to the operation and efficiency of the entire lighting fixture.
4. Radiation direction diagram. The 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 allowable range from 2700 to 7000 K. A shade of 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 “cold white”. Most often, lamps with warm light are much more expensive than cold ones, as this is directly related to the peculiarities of their production.
6.Color rendering index. This value shows how faithfully the color of an object will be displayed, which is illuminated by the selected fixtures. The higher this parameter, the more truthfully the shade of the original object is transmitted.
7. The performance of lighting fixtures. The best decision is to choose branded manufacturers, as such companies can provide more accurate LED specifications, so that the device will last the advertised operating time. Also, such lamps provide protection against power surges and overheating.
8. Instrument size. No need to judge the disadvantages and advantages based on the size of the crystal. It doesn't matter if the LED is large or small, the most important is its power.

Given 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 of well-known companies that publish open data on the reliability of their devices);
- the use of a specially designed construct and form for the fastest possible heat removal, regulating the temperature regime during the operation of the chip;
- optical (lighting) specifications of the LED lamp, which can be obtained from an independent laboratory or manufacturer;
- high-quality guarantee certificates;
- results of the results of long-term tests of the functioning of devices.

Varieties of white

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

• Warm white light: its color temperature is 2700 K and it has a slight yellowish tint, similar to the flame emitted by a candle. It is this shade that is typical for incandescent lamps, it soothes and relaxes. It is important to note that the use of a matte or transparent cover will change the shade to a softer or more saturated one. This type of light is not the main one, but it is perfect for additional and decorative lighting, it will be ideal for installation in bedrooms. Thanks to him, you can create harmony and home warmth in the room.
• natural white light A: 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 kitchen worktops or office desks. Like warm light, natural light has several shades. Luminaires and lamps with matte dispersion will have a completely different spectrum of saturation than devices with a transparent bulb. It contributes to a more precise and directional light than matte, through which soft highlights of an unobtrusive shade are emitted.
• cold white light: Its color temperature is 6000K. It has a peculiar bluish tint. This tone is very bright and is most often used for offices, as well as local lighting. It has become quite widespread in parking lots, in porches, in the local area, as well as in parks, alleys and squares. Often installed to illuminate street advertisements, commercial signs and more.

Varieties 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 practically does not differ from the usual ones, however, for its manufacture, a built-in multivibrator circuit is used, which flickers with a break of 1 second. The main types of such diodes distribute single-color light beams, more complex in their characteristics can flash in several shades alternately or simultaneously, thanks to the RGB parameter.

2. Multicolor flashing LEDs, whose characteristics 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. Thanks to this type of work, a third color is also formed, since the two main ones are mixed.

3.Tricolor LEDs, the parameters and characteristics of which are the presence of several light-emitting diodes that are not connected to each other, but combined in one housing. They work separately, they can glow at the same time, but their control remains completely different.

4. Light emitting RGB 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 the starburst format. Such screens show all numbers, and some even a certain set of letters. Using Starburst allows all symbols to be displayed.

Quite common in the 80s, alphanumeric and numeric displays became less popular after the advent of LCD monitors.

Benefits of LED Lighting

As a relatively new technology, LEDs are in most cases superior to many light 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 as an excellent alternative to fluorescent tubular and high pressure lamps. But it will still be a short time before such technologies are used in the public domain.

What does the SMD marking mean?

The decoding of such an indicator sounds like Surface Mounted Device, which translated into Russian means "a device that is mounted on the surface." A diode acts as such a device, and the surface in our case is the base of the tape.

Any SMD-LEDs, the characteristics of which are similar to the parameters of all other similar lamps, consist of several crystals placed in a housing with contact leads, as well as lenses that form a luminous flux. It is emitted by semiconductors and sent to a miniature optical system, which is formed by spherical reflectors, as well as a transparent housing of 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 strip based on SMD bends very well in the longitudinal direction.

What does the DIP LED marking mean?

There are also LED-light-emitting diodes on sale, the characteristics of which are very similar to SMD. According to their technical parameters, they are a cylindrical body, which is placed on the end tape. This type has good silicone protection. The numbers that are present in the marking, as well as for SMD, mean the diameter of the diode.

To illuminate furniture, you can use such crystals, only for glass shelves. Unlike the previous tape, this kind of bends very well in the transverse direction.

Parameters of high-quality LED flashlight

Today, a large number of conventional flashlights can be purchased on the market, but they are being actively replaced by LEDs. This happened primarily due to the fact that the latter give a 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 prefer 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, and models with a narrow beam can illuminate distant objects well. Most often, tactical devices used by tourists, hunters and cyclists have such lighting.

Another important factor affecting the performance 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, it is necessary to use lithium-ion batteries that 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 presence of marking serves as a guarantee of the quality of the selected devices. In the absence of it, we can talk about a non-certified product, most often made in China.

CREE LEDs

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

CREE LEDs, whose characteristics are presented, remain competitive in their industry:

They have record values ​​of luminous flux, reaching 345 lumens at a current of 1000 mA;
- low thermal resistance;
- relatively extended study angle;
- miniature, evenly distributed crystal;
- maximum current reception up to 1500 mA;
- an improved silicone lens instead of the glass used;
- the maximum operating temperature of the crystal is 150 °C.

As you can see, such technologies are just coming into force and bring exceptional benefits from their use. New discoveries are being made every day, LED lamps are becoming more economical and brighter, thanks to which they are beginning to rightfully occupy a leading position in the light arena.

Features of SMD 5050 tapes

LEDs of this series have a size of 5x5 mm and a luminous flux depending on the 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 of coatings, namely polyurethane and silicone. The former can only be placed indoors, while the latter, respectively, are also suitable for the street, since they are not afraid of excessive humidity.

5050 LEDs, whose characteristics and properties help to create bright light, consist of three dies with different or identical diodes in one package. Multi-colored lamps are called RGB (red-green-blue), after connecting the controllers, they 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;
- multiplicity of cutting - 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, which features high thermal conductivity and low resistance, ensures a long service life of the device. They are resistant to vibration, high humidity and temperature changes. Small enough, have a wide angle of light and are perfect for any mounting surface. They are available in spools and tapes.

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

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

Phosphor white LEDs with a nominal power of 0.5 W are distinguished by a long service life, stable performance and high-quality performance;
- high resistance to temperature changes, vibrations and high humidity of the environment;
- 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.

Understanding what parameters the flashlight operation depends on is equally important for those who want to choose a ready-made model for themselves, and for those who want to design a device with their own hands (whether it’s a flashlight keychain with an LED, pocket, head or hiking version). Repair of flashlights mainly depends on their device, and the replacement of 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 single out a universal device that is equally effective in all conditions. After all, a small flashlight can never match powerful stationary equipment, and homemade devices are far from always superior to ready-made ones (even Chinese-made ones), and it's not just how the LED was chosen.

Dimensions

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

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

Luminous flux parameters

Often, it is the brightest flashlight that is required, but not always a large number of lumens fully determine this indicator. An equally important role is given to the angle of dispersion of illumination. Lighting a small area can be handled by a simple keychain flashlight with an LED or any pocket option. The narrower the beam, the farther the device can shine, for example, a headlamp for hiking.

Important: The lens can radically change the characteristics of the device. The operation of focusable lights 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

It is the light source that determines most of the performance of a flashlight (how bright it is). The operation of the device is affected not only by the LED itself, but also by the magnitude of its operating current. The current strength must be taken into account so as not to inadvertently burn the device, because the repair of the lantern is not always in place. The LED and their strings can be grouped in different ways to increase the 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 due not only to the choice of battery, but also to the flashlight mode, for which the LED is responsible. For both homemade devices and ready-made ones, you can mount a timer to save energy. Autonomous mode can be calculated in hours (pocket and headlamps) and even days (emergency and search), this period is mainly influenced by the main characteristics.

Types of batteries

Batteries differ depending on the principle of obtaining energy, 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 run on conventional 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 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 need repairs.

Mode classification:

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

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. It can be quite difficult not only with self-assembly, but also after acquiring ready-made models. It is better to check water resistance in advance, especially on Chinese-made flashlights, in order to be able to carry out repairs in time.

Location of fasteners

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

Current stabilization

The mode of operation of the flashlight on LEDs directly depends on the supplied current, while other characteristics may be similar. Stabilized devices are considered brighter and more stable, but quickly go out when discharged. An unstabilized flashlight is less bright, but the lamps go out gradually, reducing their brightness to 0 over time.

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