Characteristics of LEDs for flashlights. Repair and power increase

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.

In the further development of flashlights, manufacturers went 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 flashlights are modern flashlights of 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 heated through the semiconductor, the current increases, as a result of which the heating becomes even stronger, the power is released even more, this avalanche-like leads to a 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 are either ready-made solutions or home-made ones.

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!

To move or work in the dark, you need a flashlight. They come in different types ranging from small pocket ones to large military or search engines. The design and power of the flashlight depends on its purpose, for example, in order to illuminate the keyhole in a dark entrance, a low-power pocket flashlight is enough, and for tourists, a camping flashlight that can shine in all directions, like a kerosene lamp, and a waterproof shockproof lantern to move around in conditions of poor visibility. In this article, we will look at how to choose a powerful LED cordless torch for your purposes.

Criterias of choice

To make the right choice of LED lamp, you need to take into account a number of factors, including:

1. Type and power of LEDs. The brightness and energy consumption depend on them.
2. Colorful temperature. The comfort of use depends on it.
3. Capacity and type of batteries. Influences the duration of work.
4. Reflector and optical system. It depends on them how much the light flux will be focused.
5. Design features. Impact resistance, water and dust resistance, usability, carrying and holding.

Types of LEDs

Various LEDs can be used in flashlights, and every year more and more powerful and brighter models come out. However, this does not prevent us from dividing them into the main types used:

1. 5mm LEDs. Previously used in all LED lights, now it is an outdated type of LED, the reason for this is their low brightness and significant energy consumption. To get a strong luminous flux from a flashlight, you have to install a lot of such LEDs, which is not always possible, since such a flashlight does not fit in your pocket.

The photo below shows an example of lanterns on 5 mm LEDs.

1. SMD LEDs.

Various types can be used - 5050, 3528, 5730 and others. They have two advantages - high power and small dimensions. This allows you to achieve a good luminous flux for small-sized lamps. Matrices of such LEDs are installed on camping lanterns and lanterns of other types with a diffused light mode function. It allows you to illuminate a large area from one flashlight with a scattered stream, albeit with loss of illumination, rather than a focused bright beam.

1. Powerful LEDs 1, 3, 5 watts. Two groups can be distinguished here:

• Noname LEDs.
• Branded LEDs, such as CREE brands and its popular XM-l models and others.

Accordingly, cheap Chinese LEDs are installed in products of the budget price segment, and branded LEDs are installed in more expensive lamp models. The differences are in the specific luminous flux - the number of Lumens per 1 watt of power, in other words, the efficiency. This determines not only how bright the flashlight will shine, but also how long it will work on a single battery charge. It is also observed that cheap high-power LEDs fail faster, like any noname products.

What LEDs are installed in powerful flashlights

As already mentioned, the most common are CREE LEDs, we have prepared a summary table with the characteristics of popular LED models 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	<150	<85	<85	<85
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

And more powerful.

Name	Cree MT-G2	Cree MK-R	Luminus SST-50	Luminus SBT-90
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	<85	<150	<85	<85
Luminous flux, Lm	440	510	1250	2000…2500
Luminescence angle, °	115	120	100	90
Color rendering index, Ra	<70	70-90	80-90	80-90

But LEDs can be designated in a different way, with a shorter marking, for example:

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

This video shows the process of replacing such an LED.

Colorful temperature

For flashlights, color temperature is not as important as color temperature for indoor lighting. However, it is worth paying attention to it. is perceived as softer to the eye, while neutral and cold shades make you be more attentive and focused.

Batteries

Now the leading place in sales is occupied by Li-ion batteries. The reason for this is their large capacity with small dimensions, good current output, and the almost complete absence of the memory effect. There are also disadvantages that should be remembered - in the cold, lithium-ion batteries are discharged faster than in heat, and when a lithium can is closed without protection, a reaction will occur with a large release of heat, up to an explosion.

Powerful LED flashlights are most often equipped with lithium batteries, in addition to them, there are other types of batteries:

• Ni-Cd - nickel-cadmium.
• Ni-Mh - nickel-metal hydride.
• Pb - lead.

But recently they are used in flashlights less and less.

Reflector and optical system

The design of the reflector and the presence of lenses affect the shape of the light spot. Some models have the ability to move the lens, which allows you to focus the beam of light. Lenses collect the light flux, as a result you get a more illuminated space, but smaller in area than without focusing.

But for different tasks, a light beam of different sizes is also needed. For example, if the flashlight will be used to repair a car, then in most cases, models with the ability to focus are better to illuminate a large area when troubleshooting, and then narrow the beam of light to a small but bright point when fixing or studying it in detail. At the same time, a focused spot is not needed for driving in the dark; lights that widely illuminate the space in front of them are better suited.

Types by purpose

In addition to the elements used and their features, when choosing flashlights, they also differ in purpose. To choose the right LED flashlight for specific tasks, you need to clearly understand what you will use it for, because there are no universal models as such.

Military and special devices

The main feature of military flashlights and lighting devices for special purposes is, first of all, the high strength of the body and its resistance to moisture. These devices include search lights that shine brightly and far away, which allows you to find something in difficult conditions, such as in the forest or in large rooms.

Models for technical personnel

Lanterns for technical personnel should be compact and have a long operating time. Their size and weight should not complicate the movement of the worker, who already carries tools and parts with him. An excellent addition to such a device would be the ability to focus the light beam and a head mount.

For outdoor recreation and tourism

For tourists, search and camping lights are suitable, as well as those used for military purposes, since the conditions in which they will work are similar - humidity, the possibility of bumps and falls, and so on. A camping lantern resembles a kerosene lamp, is a broadly directed or directed in all directions lighting device. It is convenient to use, for example, when preparing for an overnight stay and dinner. You should also pay attention to flashlights with a built-in generator. They can either work without batteries, or be recharged by acting on the generator lever (rotation or rhythmic pressing on the handle, depending on the design).

How to convert an ordinary flashlight to LED

Let's look at how to make a DIY LED flashlight. To do this, you will need the following set of parts and tools:

1. Frame. You can take from an old lantern or do it yourself, as an option, print it on a 3D printer.
2. LEDs. Selected individually.
3. or resistors to limit their current.
4. Battery.
5. Battery charge controller or charger suitable for the type of batteries used.
6. Button to turn on or toggle switch.

If you will use high power LEDs, you will need a circuit board on an aluminum substrate.

To improve heat dissipation, you need to use a radiator, you can take it from the motherboard. Small heatsinks are installed on chipsets, northbridge, power switches and other board elements.

To charge and protect the 18650 battery, you can use the TP4056 board with protection, you can order it on Aliexpress or buy it in a radio store, it costs 20-50 rubles.

Interesting: This board can be used to replace disposable batteries in a flashlight or to convert any device to batteries.

We pack it into the body of the flashlight, if it is iron, as in the photo, do not forget to provide insulation for all boards.

To power the LEDs, you can use a specialized driver or a switching boost converter, for example, MT3608. The output voltage is set using a multi-turn potentiometer, in the photo below it can be recognized by the blue case.

Expert opinion

Alexey Bartosh

Specialist in the repair, maintenance of electrical equipment and industrial electronics.

If you use a driver for power, then its main characteristics are the output current and power, it depends on how many LEDs you can connect in series.

It is necessary to select such a voltage that the current is 10-30% lower than the nominal one. For 1 W LEDs, the rated current is in the range of 300-350 mA.

A less complicated way is to select the operating mode for heating the LEDs. That is, gradually increase the voltage, trying the radiator by touch, it should not warm up, or its temperature should be less than 50 degrees Celsius, this is the temperature when, when touched, the hand still tolerates it and you do not want to pull it up. This is an inaccurate method, so it is better to focus on both current and heating.

The second option is easier. To replace an incandescent lamp with an LED, you need to take an old light bulb, break the bulb, remove all the insides so that only the base remains. Further, an isolated output of the LED with a soldered resistor, selected for the appropriate voltage, is inserted inside the base.

When purchasing or assembling new LED flashlights, you should definitely pay attention to the LED used. If you buy a flashlight only to illuminate a dark street, then there is a huge choice - we choose any with a bright white LED. But if you want to buy a portable lighting device with characteristics for more complex tasks, then the important point is the choice of the appropriate luminous flux, that is, the ability of the device to illuminate a large area with a powerful beam.

Main characteristics

LEDs are responsible for the quality of light emitted by the flashlight. The stability of lighting depends on many characteristics, among which are current consumption, light flux and color temperature. Among trendsetters it is worth noting the Cree company, in its assortment you can find very bright LEDs for flashlights.

Modern pocket models are created on a single LED, the power of which reaches 1, 2, or 3 watts. The indicated electrical characteristics are the properties of various LED models from well-known brands. The intensity of light rays or luminous flux is an indicator that depends on the type of LED and the manufacturer. The manufacturer also indicates the number of lumens in the characteristics.

This indicator is directly related to the color temperature of light. Light emitting diodes can emit a light output of up to 200 lumens per watt and are produced today with different temperatures for glowing: warm yellowish or cool white.

In flashlights with a warm white tint, the radiation is pleasant to the human eye, but they shine less brightly. Light with a neutral color temperature effectively makes it possible to see the smallest elements. Cool white lighting is usually typical for models with a huge range of light beam, however, with prolonged use, it can irritate the eyes.

If the temperature reaches about 50 °C, then the life of the crystal can be up to 200,000 hours, but this is not justified from an economic point of view. For this reason, many companies produce products that can withstand operating temperatures up to 85°C while saving on cooling costs. Due to exceeding the mark of 150 ° C, the equipment may completely fail.

The color rendering index is a quality indicator that characterizes the property of the LED to illuminate the space, while there is no distortion of the true shade. Flashlight LEDs with a CRI of 75 CRI or more are a good option. An important element of the LED is a lens, thanks to which the angle of dispersion of light fluxes is set, that is, the range of the beam glow is determined.

In any technical characteristic of the LED, the angle of radiation is necessarily noted. For any of the models, this characteristic is considered individual and usually varies in the range from 20 to 240 degrees. High-power LEDs for flashlights have an angle of up to approximately 120 °C, and generally include a reflector and an additional lens.

Although today we can see a strong leap in the production of high-power multi-chip LEDs, global brands are still producing LEDs with lower power. They are produced in a small case, which does not exceed 10 mm in width. In a comparative analysis, it can be seen that one such powerful crystal has a less reliable circuit and scattering angle than a pair of similar elements in a single package at the same time.

It would not be superfluous to recall the four-pin LEDs "SuperFlux", the so-called "piranha". These flashlight LEDs have improved specifications. The piranha LED has the following main advantages:

1. the flow of light is evenly distributed;
2. no need to remove heat;
3. lower price.

LED types

There are many flashlights with improved properties available on the market today. The most popular are LEDs from Cree Inc.: XR-E, XP-E, XP-G, XM-L. The latest XP-E2, XP-G2, XM-L2 are also popular today - they are mainly used in medium-sized flashlights. But, for example, Cree MT-G2 and MK-R LEDs from Luminus are widely used in huge models of search lights that can operate simultaneously from a pair of batteries.

In addition, it is customary to distinguish LEDs by brightness - there is a special code, thanks to which you can sort the LEDs by this parameter.

When comparing some diodes with others, you should pay attention to their dimensions, or rather, to the area of ​​light-emitting crystals. If the area of ​​such a crystal is small, then it is easier to concentrate its light into a narrow beam. If you want to get a narrow beam from XM-L LEDs, then you will need to use a very large reflector, which negatively affects the weight and dimensions of the case. But with small reflectors on a similar LED, a fairly effective flashlight will come out.

Scope of LEDs

Basically, when choosing flashlights, consumers choose models with a maximum glow beam, but in many cases they do not need this option. In many cases, such equipment is used to illuminate the nearby area or an object that is located at a distance of no more than 10,000 m. A long-range flashlight shines at 100 m, although in many cases with a rather narrow beam that poorly illuminates the surrounding area. As a result, when lighting a distant object with such lighting fixtures, the user will not notice those objects that are located in the immediate vicinity of him.

Consider a comparison of the tonality of light that LEDs give: warm, neutral and cold. When selecting the appropriate light temperature for a flashlight, the following important points should be taken into account: Warm LEDs can minimally distort the color of illuminated objects, but they have a lower brightness than neutral spectrum LEDs.

When choosing a powerful search or tactical flashlight, where the brightness of the device is an important point, it is recommended to select an LED with a cold light spectrum. If a flashlight is needed for everyday life, tourist purposes or for use in a head model, then competent color reproduction is important here, which means that LEDs with warm light will be more advantageous. The neutral LED is the golden mean in all respects.

Aside from the cheapest flashlights, which have only one single button, many flashlights have a couple of modes of operation, including strobe and SOS modes. The non-branded model has the following operating options: the highest power rating, the average power, and the "strobe". In addition, the average power is basically 50% of the highest light brightness, and the lowest is 10%.

Brand models have a more complex structure. Here you can control the mode of operation with the help of a button, the rotation of the “head”, the rotation of the magnetic rings and a combination of all of the above.

Hello everyone, I bring to your attention a powerful homemade flashlight. Now you will not be afraid of any darkness. Homemade is assembled quite simply, all materials are purchased and easy to get. So, for example, the author made the body of the lantern from plumbing pipes and parts for them. This flashlight is equipped with lithium batteries, which allows you to easily charge it. So, let's take a closer look at how to assemble such a flashlight!

List of tools:
- drill;
- hacksaw for metal;
- soldering iron;
- wire cutters;
- screwdriver;
- marker;
- pliers.

Flashlight manufacturing process:

Step one. Install LED on cooler
We will use a fairly powerful LED, which means that it will definitely need to remove heat from it. For these purposes, we will need a small aluminum heatsink.

We mark the places, drill holes and cut the threads for the screws. Next, we fasten the LED to the radiator. Be sure to apply thermal paste to the radiator, otherwise the heat transfer will be low and the LED will overheat.

Step two. Making the body
As a case, we need a piece of PVC sewer pipe, it will contain two batteries of 4000 mAh each. As for the radiator with LED, it will be installed inside the cone-shaped part. Since the filling did not completely fit into it, the author slightly increased the length of the part. He cut a piece off another tapered piece and glued it on with superglue. We also need a plug for pipes, there will be a connector for the charger.

Today, LEDs are embedded anywhere - in toys, lighters, household appliances, and even in stationery. But the most useful invention with them is, of course, a flashlight. Most of them are autonomous and give out a powerful glow from small batteries. With it you will not get lost in the dark, and when working in a dimly lit room, this tool is simply indispensable.
Small copies of a wide variety of LED flashlights can be bought at almost any store. They are inexpensive, but the build quality can sometimes not please. Whether it's home-made devices that can be made on the basis of the simplest parts. It is interesting, informative and has a developing effect on tinkerers.

Today we will look at another homemade product - an LED flashlight, made literally from improvised parts. Their cost is no more than a few dollars, and the efficiency of the device is higher than that of many factory models. Interesting? Then do it with us.

The principle of operation of the device

Required Parts

• 20 ml plastic syringe;
• Lenses for LED flashlight with housing;
• Micro button switch;
• Resistor 3 ohm / 0.25 W;
• A piece of aluminum plate for a radiator;
• Several copper wires;
• Superglue, epoxy or liquid nails.

Assembling a powerful LED flashlight

Preparing the LED with lenses

Processing a flashlight body from a syringe

Connecting the Micro Charging Module and Battery

Final assembly of the flashlight