What LEDs for flashlights are more powerful. Characteristics of LEDs for flashlights
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Main characteristics of SMD 5730 LEDs
Modern products with geometric parameters of 5.7 × 3 mm. Due to their stable characteristics, SMD 5730 LEDs belong to the category of super-bright products. For their manufacture, new materials are used, so that they have increased power and highly efficient luminous flux. SMD 5730 allow operation to work in conditions of high humidity. They are not afraid of vibration and temperature fluctuations. Differ in long service life. They have a scattering angle of 120 degrees. After 3000 hours of operation, the degree does not exceed 1%.
Manufacturers offer two types of devices: with a power of 0.5 and 1 watt. The first are marked SMD 5730-0.5, the second - SMD 5730-1. The device can operate on pulsed current. For SMD 5730-0.5, the rated current is 0.15 A, and when switching to a pulsed operating mode, it can reach 0.18 A. It is capable of generating a luminous flux of up to 45 Lm.
For SMD 5730-1, the rated current is 0.35A, the pulse current can reach 0.8A with a light output efficiency of 110 Lm. Due to the use of a heat-resistant polymer in the production process, the body of the device is not afraid of exposure to sufficiently high temperatures (up to 250 ° C).
Cree: current specifications
The products of the American manufacturer are presented in a wide range. The Xlamp series includes single-chip and multi-chip products. The former are characterized by the distribution of radiation along the edges of the device. Such an innovative solution made it possible to arrange the production of lamps with a large glow angle with a minimum number of crystals.
The XQ-E High Intensity series is the company's latest development. Products have a glow angle of 100-145 degrees. With relatively small geometric parameters of 1.6 by 1.6 mm, such LEDs have a power of 3 V with a luminous flux of 330 Lm. The characteristics of Cree LEDs based on a single chip allow you to provide high-quality color rendering CRE 70-90.
Multi-chip LED-devices have the latest type of power supply 6-72 V. They are usually divided into three groups depending on the power. Products up to 4 W have 6 crystals and are available in MX and ML packages. The characteristics of the XHP35 LED correspond to a power of 13W. They have a scattering angle of 120 degrees. They can be warm or cool white.
Testing an LED with a multimeter
Sometimes it becomes necessary to check the performance of the LED. You can do this with a multimeter. Testing is performed in the following sequence:
| Photo | Description of works |
|---|---|
 | We prepare the necessary equipment. An ordinary Chinese multimeter model will do. |
 | We set the resistance mode corresponding to 200 ohms. |
 | We touch the contacts to the element being checked. If the LED is working, it will start to glow. |
Attention! If the contacts are mixed up in places, a characteristic glow will not be observed.
Color marking of LEDs
To purchase an LED of the desired color, we suggest that you familiarize yourself with the color symbol that is part of the marking. At CREE, it is located after the designation of a series of LEDs, and can be:
- wht if the glow is white;
- HEW, if high efficiency is white;
- BWT for white second generation;
- BLU if blue light glow;
- GRN for green;
- ROY for royal (bright) blue;
- RED at red.
Other manufacturers often use a different convention. So KING BRIGHT allows you to choose a model with radiation of not only a certain color, but also a shade. The designation present in the marking will correspond to:
- Red (I, SR);
- Orange (N, SE);
- Yellow (Y);
- Blue (PB);
- Green (G, SG);
- White (PW, MW).
Advice! Familiarize yourself with the symbols of a particular manufacturer in order to make the right choice.
Deciphering the LED strip marking code
For the manufacture of LED strip, a dielectric is used, having a thickness of 0.2 mm. Conductive tracks are applied to it, having contact pads for chips, designed for mounting SMD components. The tape includes separate modules having a length of 2.5-10 cm and designed for a voltage of 12 or 24 volts. The module may include 3-22 LEDs and several resistors. The length of finished products is on average 5 meters with a width of 8-40 cm.
A label is applied to the reel or packaging, which contains all the relevant information about the LED strip. The decoding of the marking can be seen in the following figure:
Article
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.
Search light with 5mm 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 |
| 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 | ||||
| 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
Police LED flashlight with shocker 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.
- When repairing a flashlight with a stun gun, be careful, it is advisable to use rubber gloves to avoid electric shock.
- 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.
- 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.
Compare original and fake cree LatticeBright is a Chinese LED manufacturer that makes products very similar to Cree, probably a design match (sarcasm).
Comparison of the Chinese copy and the original Cree On the substrates, these clones look like this. You can see the variety of shapes of LED substrates produced in China.
Counterfeit detection by substrate for LED 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.
How to make an LED from an incandescent lamp 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!
Over the years, I have changed a great variety of LED headlamps, economy lamps, powerful, compact and underwater lamps, as well as all kinds of backup light options, gaining a lot of experience in their practical use. In this article I will try to tell you which lamps I settled on, I will try to briefly explain what types of lamps are, what light sources are, how to understand the marking of LEDs, which batteries are better to choose and why. It should be noted that I am not a fan of flashlights, they interest me solely in terms of practicality and convenience. I won't go after the extra 10% light output with a fancy $200 flashlight, I'd rather pick one that's 10% weaker but ten times cheaper. Let's start with the basic concepts.
What LEDs are used in flashlights
Since my goal is not to reveal the entire range of light sources that are used in flashlights, I will focus on the main, most popular sources, LEDs. I think I won’t be mistaken if I say that today more than 90% of produced flashlights are LED flashlights. Therefore, we discard incandescent lamps and gas-discharge lamps as ineffective for our purposes.
What kind of LEDs can be found in tourist lanterns and lamps?
The most popular LED manufacturer, Cree, divides its products into two types. These are powerful LEDs, under the general name XLamp and super-bright ( high-brightness). They differ in power consumption, the first group includes LEDs with a permissible current value of 350 mA and above. Super-bright ones are designed for a lower operating current, an average of 30-50 mA. In the third group, I would include COB LEDs, this is a relatively new technology that allows you to place several light-emitting crystals in one housing. The advantage of this technology is the relative cheapness of such elements, since each element does not need a separate case and does not need to be soldered separately. The downside is that the energy efficiency from placing several crystals in one housing has not improved, but the area of \u200b\u200bthe radiating surface has increased, which is critical for powerful long-range flashlights, a larger light source is more difficult to focus.
These are all surface mount diodes, they are mounted on a heat-conducting substrate. There are also indicator-type LEDs, on legs, which are mounted in holes on the board (since there is no problem with heating). They have a rather low brightness, but at the same time they are extremely low-power (below 25 mA), which allows them to be used in those lamps and lamps for which it is not the brightness that is critical, but the duration of operation.
Now I will try to explain with examples what types of diodes are used for what purposes, and also tell you how to decipher the names of LEDs.
What makes the LED glow? A little about drivers
For the operation of the LED, two parameters are important - operating voltage and current. The operating voltage of an LED is sometimes referred to as "voltage drop". This means that after passing through our LED, the voltage in the circuit will be less than exactly the amount of this "drop". If we supply 6 volts to the LED, which has a voltage drop of 3.7 V, then it will consume them, and the device connected after it to the same circuit will get 2.3 volts. But the most important thing for us: the current is important to the LED, not the voltage.
He will take as much voltage as he needs, but the current will try to absorb the whole. If your power supply can deliver 100 amps, the LED will draw current until it burns out. The scheme of operation is simple: the LED consumes current and heats up from this. When heated, the resistance of the LED drops, which means more current can pass through it, it heats up even more, the resistance drops even more, and so on. If you do not limit the current, then the LED will simply burn out. Therefore, there must be a limiting element in the LED power circuit.
In general, in series with the LED, we need to put a current limiter, a "neck" through which no more will pass than our LED can absorb. This element is called "driver". The simplest driver is a resistor. It is used in those circuits where there is no brightness control of the glow and the voltage of the power source does not jump.
More complex drivers are able to stabilize the operating voltage at the level of the LED voltage drop, as well as regulate the current strength, thereby changing the brightness of the glow. The driver is also responsible for various flashlight modes (flashing light, SOS, etc.).
I must say that the brightness and durability of the flashlight depends on the driver.
Use of powerful Cree LEDs in flashlights
Let's start with high-power Cree LEDs, since most of the high-power flashlights that you have to choose from will be built on Cree diodes. What you need to know about these LEDs to choose the right one? The first is production technology, such as XM-L and XM-L2. With the same power of 10W and maximum current, the XM-L LED will produce a luminous flux of 1000 lm, and the Cree XM-L2 - almost 1200 lm.
However, in the marking of diodes, the so-called luminance bin. Technological variation is possible during manufacture, so each batch of LEDs is sorted by brightness and color shade of white. The brightest diodes are sold more expensive, less bright - cheaper. Cree's brightness marking goes from bin J - this is about 30 lumens at a current of 350 mA, to bin U2 - more than 300 lumens at the same current.
What else matters? The shade of the emitted light. The main sources of light in nature are heated bodies. Therefore, initially the spectrum of visible radiation, which depends on the heating temperature, measured in Kelvin, is called the term "color temperature". In the description of LED lights that you can buy on Aliexpress, you rarely see an indication of the color temperature, usually the terms "Warm white", "White" and "Cool white" are used there, which means "warm white", "white" and "cold" white". From personal experience I can say that in most cases it is worth choosing a cold white. I compared in field conditions, in the summer, on fishing. With the same brightness of the glow in a beam of cold white light, the picture is more contrasting, more detailed.
That is, if we need the brightest flashlight, then we should choose a XM-L2 LED flashlight with a U2 brightness bin and a cool white glow.
For example, a table of the color temperature of natural light sources.
Okay, we chose an LED flashlight. Powerful, bright. The question remains: how are we going to feed it? The Cree xm-l2 LED consumes 3A in maximum mode, and in normal mode 700 mA at 2.85 volts, it is usually powered by 18650 lithium batteries, the maximum capacity of the most expensive is 3700 mAh at 3.7 volts. Thus, under ideal conditions (if you do not take into account the efficiency of the driver), our flashlight will work from the most expensive battery for only 96 minutes at maximum brightness, or about 6 hours at normal.
And here the question arises: will six hours of operation of the lantern be enough for one fishing trip? Does it make sense to spend five dollars for one battery, which is enough for 6 hours of a not very bright glow, or is it better to order a flashlight that is less bright, but more long-lasting? Do we need a flashlight of such crazy brightness (and 1200 lumens is the brightness of a 100W incandescent lamp), or is half enough? This is where we begin to consider other types of LEDs in flashlights, for example, XR-C, XR-E, XP-C or XP-E, which, although they give out a smaller brightness bin during operation, are much less voracious. I will not describe the characteristics of these LEDs, you can easily find them in search engines. Below, in the descriptions of the lights, I will mention which LEDs and what I used.
Lantern Small Sun ZY-A21
I bought it as a good long-range flashlight powered by nickel AA or lithium 14500 batteries. At first I was very pleased with the brightness, but the manufacturer let me down: he installed the wrong driver. A couple of years after the purchase, the flashlight started flashing, I took it apart, measured the voltage and current. It turned out that the driver in the maximum mode gives a current of 2.1 A, and in the "half" mode 1.1 A, with a maximum allowable current of 1A for the installed Cree XR-E LED. This increased the brightness of the glow, but greatly reduced the life of the diode, which turned black as a result.
Taking advantage of the fact that LEDs are on Aliexpress, I ordered an XP-L LED instead of XR-E, which can easily digest 3 amperes. The only thing, as I said, in vain I ordered a warm white. Should have ordered cold.
What happened as a result: the brightness increased greatly, both in maximum and in half mode. But due to the different shape and size of the LED, the size increased and the clear border of the light spot disappeared, since the lamp reflector was designed for the "lensed" XR-E. Range remains the same: high brightness compensates for defocusing. A huge plus is that the LED works in a gentle mode and now the flashlight will last a very long time.
General thought: I very rarely use this flashlight for its intended purpose. Mostly he lies at home in case of a power outage. For those who need to shine far and brightly, it would suit more. For example, a security guard of a large area to shine a light on who walks there at the other end of the hangar, and, if necessary, to crack the villain in the head with him. When fishing, in 99% of cases a headlamp is enough.
Due to the fragility, the A21 flashlight is no longer produced, and I would not recommend it. But with the XP-L diode, it has every right to exist, so I will recommend two budget flashlights from a trusted manufacturer, of the same design, with XP-L and XM-L diodes (the first is brighter, but more expensive by a couple of dollars).
Headlamps from Aliexpress
Fishing headlamps are indispensable, so I have five of them. First, I rarely go fishing alone. Secondly, a lantern for a fisherman or a tourist is an essential item: you should always have two spare ones. And finally, the first flashlight was bought about fifteen years ago, when there were legends about Cree LEDs, and enthusiasts bought flashlights on these diodes for a lot of money. By and large, then there were no normal batteries, so the most important indicator for a headlamp was the operating time from one set of batteries. Let's start with him.
Economical headlamp with indicator LEDs
The most popular flashlight of the mid-2000s. I have seen versions with 3, 9, 12, 18 and even 24 LEDs. Crazy numbers up to 500 lumens were written on the packages, but in fact indicator LEDs have a brightness of about 2 lumens per piece. They had no height adjustment, no beam focusing, but they weighed only about 30 grams. At the same time, a huge plus is energy consumption, or rather, its absence. The operating current of one diode, depending on the model, is up to 20 mA. The flashlight, forgotten in the bag, turned on at minimum brightness, on the next fishing trip, a week later, was still glowing. At full brightness, another flashlight could work for two days in a row. Of course, it is difficult to find such a grandfather now, but the flashlight can successfully replace it: a super-bright COB diode, at least a day of operation at full brightness and up to a week of operation in an economical mode (from alkaline batteries). And all this joy is cheaper than two dollars.
Another lantern that is close in ideology, with an important improvement: the ability to adjust the angle of inclination. Instead of indicator LEDs, COB is used, this greatly increases the brightness, although it reduces the operating time. The price is the same.
Absolutely one such lantern is a must have. I always keep it in my car, in case you need to change a wheel, a fuse or check the oil level at night, or if the rest of the lights get wet while fishing. Eneloop batteries are installed inside (in another article), they calmly hold a charge for more than a year.
A headlamp that has stood the test of time
I bought two in 2011 when the first available Cree Q5s went on sale, I remember it cost me $16. This is quite a serious lantern, with a beam adjustment, which can be used to illuminate the fish when playing, and hang it over the table at dinner. A set of batteries is enough for one night. There is a tilt adjustment, a comfortable belt. A good economical option, at the current price.
I highly recommend this flashlight if you have several sets of AAA batteries that can be used in this flashlight. If not, read on.
Headlamp on Cree XM-L with Aliexpress
Powerful LED headlamps that have actually replaced all other flashlights for me. I bought the first one when I saw one from a friend on a fishing trip. A huge supply of brightness, in the maximum mode is used very rarely, but is indispensable when playing a large fish: even a wide beam breaks through the water for several meters. For example, if you stand on a cliff and play a large catfish into a landing net with a four-meter handle, then you see the landing net itself, and all the maneuvers of the fish are under your control.
Purchased with batteries and car charger. A big plus is that you can recharge directly in the car. The downside is that I got the version with a socket for one battery. Now they sell a version for two batteries for the same money (about $7). Why do I recommend the dual battery version? Cree XM-L is a very powerful LED, in maximum mode up to 10 watts. I bought 12 2600 mAh batteries, one battery lasts for an hour in maximum mode and three hours in economy mode. If fishing all night, the battery has to be changed. Two batteries (5200 mAh) would be enough for the night, and since the discharge current per bank would be half as much, this would increase the operating time by another 15 percent. And two-cell lights, if necessary, can easily work with one battery, since the connection is in parallel. The weight of the extra battery can be ignored, since it is located on the back of the head and is not felt at all.
Flashlights, so I bought myself one thinking I had completed my search for the perfect flashlight for my needs. Be careful: after purchase, it is advisable to unwind this lantern and drip sealant into the threaded connection. This will protect you from a lens suddenly flying into the snow, which is very inconvenient to look for at night, but it will allow you to disassemble the lantern if necessary (I can’t imagine why, but you never know).
Just now, when I took a photo of the lights for this article, I noticed that the second light is not XM-L, but XP-E2. I was sure that XML was there and was upset at first, but I remembered that in the fall in the field I used both lamps in turn and did not notice the difference. Most likely because the XP-E2 has twice the area of the emitting surface, due to which the beam is better focused. But it consumes three times less energy, ie. will work three times longer. Perhaps this is really the perfect flashlight: 12 hours at half brightness, 5 hours and a powerful thin beam at full brightness, the best compromise between brightness and operating time.
Comparison of flashlight brightness on XP-L, XM-L and XP-E2
Final photo illustrating the previous text.
- In the center is an XP-L V5 LED flashlight. As expected, it gives the most light. However, the shade - warm white - softens the picture. Due to the use of a different LED in the flashlight for which it was designed, the beam is not clearly focused, the light spot has blurry edges.
- On the left is a XM-L T2 LED lamp, cool white shade. Not as bright, but well focused. The picture is more contrast.
- On the right is the flashlight on the XP-E2. The light spot is smaller, excellent focus, brightness is also decent.
Draw your own conclusions. At the moment, I most often use the third flashlight.
Since the invention of electric lighting, scientists have created more and more economical sources. But a real breakthrough in this area was the invention of LEDs, which are not inferior in terms of 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:
The principle of operation and the device of light diodes
LEDs are distinguished from the usual lighting devices by the absence of a filament, a fragile bulb and gas in it. This is a fundamentally different element. In scientific terms, the glow is created due to the presence of p- and n-type materials in it. The first accumulate a positive charge, and the second - a negative one. P-type materials accumulate electrons in themselves, while holes are formed in n-type materials (places where electrons are absent). At the moment when an electric charge appears on the contacts, they rush to the p-n junction, where each electron is injected precisely into the p-type. From the side of the reverse, negative contact of the n-type, as a result of such a movement, a glow occurs. It is due to the release of photons. However, not all photons emit light visible to the human eye. The force that makes the electrons move is called the LED current.
This information is of no use to the general public. It is enough to know that the LED has a solid housing and contacts, which can be from 2 to 4, and that each LED has its own nominal voltage required for glowing.
Good to know! Connection is always made in the same order. This means that if a “+” is connected to the “-” contact on the element, then there will be no glow - p-type materials simply cannot be charged, which means there will be no movement towards the transition.
Classification of LEDs according to their field of application
Such elements can be indicator and lighting. The former were invented earlier than the latter, while they have long been used in radio electronics. But with the advent of the first lighting LED, a real breakthrough in electrical engineering began. Demand for lighting devices of this type is steadily growing. But progress does not stand still - more and more new species are invented and introduced into production, which are becoming brighter, without consuming more energy. Let's take a closer look at what LEDs are.
Indicator LEDs: a bit of history
The first such red LED was created in the middle of the 20th 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 appear, and work to improve them does not stop. By the 90th year, the strength of their luminous flux reaches 1 Lumen.
1993 is 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. In the early 2000s, the luminous flux already reaches 100 Lumens. Nowadays, LEDs do not stop improving, increasing the brightness without increasing the power consumption.
Use of LEDs in residential and industrial lighting
Now such elements are used in all industries, whether it is mechanical or automotive, 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 the old 220 V halogen lamps. Let's try to give one example. If we take the characteristics of a 3 W LED, then they will be comparable to those of an incandescent lamp with a consumption of 20-25 W. It turns out that energy savings are almost 10 times, which, with daily constant use in an apartment, gives a very significant benefit.
What are the advantages of LEDs and what are their disadvantages?
Much can be said about the positive qualities of light diodes. The main ones can be called:
As for the negative sides, there are only two of them:
- Operates 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 to pay attention to when purchasing devices based on them:
- consumption current;
- Rated voltage;
- power consumption;
- color temperature;
- the power of the luminous flux.
This is what we can see on the label. In fact, there are many more features. Let's talk about them now.
LED current consumption - what is it
The current consumption of the LED is 0.02 A. But this only applies to elements with a single crystal. There are also more powerful light diodes, which can include 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 resistance of the LED prevents the high current from instantly burning the LED element. This may be due to high mains current.
Rated voltage
The voltage of an LED is directly related to its color. This is due to the difference in materials for their manufacture. Let's consider this dependence.
| LED color | Material | Forward voltage at 20 mA | |
|---|---|---|---|
| Typical value (V) | Range (V) |
||
| IR | GaAs, GaAlAs | 1,2 | 1,1-1,6 |
| Red | GaAsP, GaP, AlInGaP | 2,0 | 1,5-2,6 |
| Orange | GaAsP, GaP, AlGaInP | 2,0 | 1,7-2,8 |
| Yellow | GaAsP, AlInGaP, GaP | 2,0 | 1,7-2,5 |
| Green | GaP, InGaN | 2,2 | 1,7-4,0 |
| Blue | ZnSe, InGaN | 3,6 | 3,2-4,5 |
| White | Blue/UV diode with phosphor | 3,6 | 2,7-4,3 |
LED resistance
By itself, the same LED can have a different resistance. It changes depending on the inclusion in the circuit. In one direction - about 1 kOhm, in the other - a few MΩ. But there is a nuance here. The resistance of the LED is non-linear. This means that it can vary 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 light 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 is the quality of "directional light" and contributes to the greatest luminous flux, which can reach 300-350 lm for a single 3 watt LED.
Power of LED lamps
LED power is a purely individual value. It can vary in the range from 0.5 to 3 watts. It can be determined using Ohm's law. P=I × U , Where I is the current strength, and U - LED voltage.
Power is a pretty important indicator. Especially when it is necessary to calculate what is needed for a particular number of elements.
Colorful temperature
This setting is similar to other lamps. The temperature spectrum is closest to that of LED fluorescent lamps. The 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, here are the main ones.
LED chip size
It will not be possible to measure this parameter on your own when buying, and now it will become clear to the dear reader 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 translated 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 Chinese-made LEDs. They can be not only of low quality, but their characteristics are most often overestimated.
What are SMD LEDs: their characteristics and difference from conventional ones
A clear decoding of this abbreviation looks like Surface Mount Devices, which literally means "mounted on the surface." 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 paws on the same side where they themselves are. 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 take a look at some of these light diodes.
LED SMD2835 parameters: dimensions and specifications
Many beginners confuse the marking SMD2835 with SMD3528. On the one hand, they should be the same, because the marking indicates that these LEDs have a size of 2.8x3.5 mm and 3.5 by 2.8 mm, which is the same. However, this is misleading. 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. Consider SMD2835 data with different power:
| Parameter | Chinese 2835 | 2835 0.2W | 2835 0.5W | 2835 1W |
|---|---|---|---|---|
| Light flux strength, Lm | 8 | 20 | 50 | 100 |
| Power consumption, W | 0,09 | 0,2 | 0,5 | 1 |
| Temperature, in degrees C | +60 | +80 | +80 | +110 |
| Consumption current, mA | 25 | 60 | 150 | 300 |
| Voltage, V | 3,2 | |||
As you can understand, the technical characteristics of the SMD2835 can be quite diverse. It all depends on the quantity and quality of the crystals.
5050 LED Characteristics: Larger SMD Component
Quite surprisingly, with 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 of them. The most common application of such elements is found 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), one-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 even super-bright LEDs. 3 volts, which feed both 5050 and 2835, give up to 50 lm at 0.5 watts here. 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 “plugged in the belt” all the rest. About them now and will be discussed.
Cree LEDs: characteristics and technical data
To date, there are no analogues of Cree products. The characteristics of their ultra-bright LEDs are truly amazing. If the previous elements could boast of 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 greater - it is 13 watts.
If we summarize the characteristics of various modifications and models of LEDs of this brand, we can see the following:
The strength of the luminous flux of SMD LED "Cree" is called a bin, which must be affixed to the package. Recently, there have been a lot of fakes for this brand, mostly made in China. When buying, 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 the LED with a multimeter - how to do it
The simplest and most affordable way is "dialing". Multimeters have a separate switch position specifically for diodes. Having switched the device to the desired position, touch the probes to the legs of the LED. If the display shows the number "1", the polarity should be reversed. In this position, the multimeter's buzzer should beep and the LED should be on. If this does not happen, then it is out of order. If the light diode is working, but does not work when soldered into the circuit, there may be two reasons for this - its incorrect location or the failure of the resistor (modern SMD components already have it built in, which will be clear in the process of “ringing”).
Color marking of light diodes
There is no generally accepted global labeling of such products; each manufacturer designates the color as it suits him. In Russia, LED color marking is used, but few people use it, because the list of elements with letter designations is quite impressive and hardly anyone wants to remember it. The most common letter designation, which many consider generally accepted. But such marking is more common not on powerful elements, but on LED strips.
Deciphering the LED strip marking code
In order to understand how the tape is marked, you need to pay attention to the table:
| Position in code | Purpose | Notation | Deciphering the designation |
|---|---|---|---|
| 1 | Light source | LED | Light-emitting diode |
| 2 | Glow color | R | Red |
| G | Green | ||
| B | Blue | ||
| RGB | Any | ||
| CW | White | ||
| 3 | Mounting method | smd | Surface Mounted Device |
| 4 | Chip size | 3028 | 3.0 x 2.8mm |
| 3528 | 3.5 x 2.8 mm | ||
| 2835 | 2.8 x 3.5mm | ||
| 5050 | 5.0 x 5.0 mm | ||
| 5 | Number of LEDs per meter length | 30 | |
| 60 | |||
| 120 | |||
| 6 | Degree of protection: | IP | International Protection |
| 7 | From the penetration of solid objects | 0-6 | According to GOST 14254-96 (IEC standard 529-89) "Degrees of protection provided by enclosures (IP code)" |
| 8 | From liquid penetration | 0-6 |
For example, let's take a specific LED CW SMD5050/60 IP68 marking. From it you can understand that we have 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 be done from LEDs with your own hands?
This is a very interesting question. And if you answer it in detail, then it will take a lot of time. The most common use of light diodes is the illumination of suspended and stretch ceilings, the working area in the kitchen, or even a computer keyboard.
Expert opinion
Engineer-designer of ES, EM, EO (power supply, electrical equipment, interior lighting) ASP North-West LLC
Ask a specialist“For the operation of such elements, a power stabilizer or controller is required. It can even be taken from an old Chinese garland. Many "craftsmen" write that a conventional step-down transformer is enough, but this is not so. In this case, the diodes will blink.”
Current stabilizer - what function does it perform
An LED stabilizer is a power supply that steps down the voltage and equalizes the current. In other words, it creates conditions for the normal operation of the elements. At the same time, it protects against overvoltage or undervoltage on the LEDs. There are stabilizers that can not only regulate the voltage, ensuring the smooth decay of the light elements, but also control the 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 tapes. Such controllers are equipped with remote controls.
The scheme of such a device is not complicated, and if desired, the simplest 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 in your hands.
daytime running lights for car
The use of light diodes in the automotive industry is quite common. For example, DRLs are made exclusively with their help. But if the car is not equipped with running lights, then their purchase can hit the pocket. Many car enthusiasts make do with cheap LED strip, but this is not a very good idea. Especially if the strength of its luminous flux is small. A good way out can be the purchase of a self-adhesive tape on Cree diodes.
It is quite possible to make DRLs with the help of those that have already failed, by placing new, powerful diodes inside the old cases.
Important! Daytime running lights are designed specifically to ensure that the car was visible during the day, and not at night. It makes no sense to check how they will shine in the dark. DRLs should be visible in sunlight.
Flashing LEDs - what is it for?
A good option for using such elements would be a billboard. But if it is statically glowing, then it will not attract due attention. 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 the controller from the same garland. The result is a flashing advertisement that will clearly attract attention.
Color music on light diodes - is it difficult to do it
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 quite within the power of everyone.
In electronics stores you can always find a sound sensor, and many modern switches have it (light on cotton). If you have an LED strip and a stabilizer, then by running “+” from the power supply to the strip through a similar cracker, you can achieve the desired result.
Voltage indicator: what to do if it burns out
Modern indicator screwdrivers consist of just a light diode and resistances with an insulator. Most often it is an ebonite insert. If the element inside burns out, it is quite possible to replace it with a new one. And the color will be chosen by the craftsman himself.
Another option is to make a chain continuity. To do this, you need 2 finger batteries, wires and a light diode. Having connected the batteries in series, we solder one of the legs of the element to the plus of the battery. The wires will go from the other leg and from the minus of the battery. As a result, when the diode is closed, it will light up (if the polarity is not reversed).
LED wiring diagrams - how to do it right
Such elements can be connected in two ways - in series and in parallel. In this case, we must not forget that the light diode must be positioned correctly. Otherwise, the circuit will not work. In ordinary elements with a cylindrical shape, this can be determined as follows: a flag is visible on the cathode (-), it is slightly larger than the anode (+).
How to Calculate LED Resistance
Calculating the resistance of a light diode is very important. Otherwise, the element will simply burn out, unable to withstand the magnitude of the network current.
This can be done using the formula:
R \u003d (VS - VL) / I, Where
- VS - supply voltage;
- VL – rated voltage for the LED;
- I - LED current (usually it is 0.02 A, which is equal to 20 mA).
Everything is possible if desired. The scheme 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 can easily withstand 6-12 elements. You can mount a colored backlight for a computer keyboard by taking 2 blue, white, red, green and yellow elements. It turns out pretty nice.
Helpful information! The voltage that the power supply outputs is 3.7 V. This means that the diodes must be connected in series with switched pairs in parallel.
Parallel and serial connection: how they work
According to the laws of physics and electrical engineering, with a parallel connection, the voltage is distributed evenly over all consumers, remaining unchanged on each of them. With sequential installation, the flow is divided and on 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 from 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, a huge range of products from various manufacturers with these parameters is presented on the shelves of Russian stores. But still, 12 V tapes and controllers predominate. This voltage is safer for humans, and the cost of such devices is lower. The independent connection to the 12 V network was mentioned a little higher, but there should be no problems with connecting to the controller - they are accompanied by a diagram that even a schoolboy will understand.
Finally
The popularity that light diodes are gaining cannot but rejoice. After all, it makes progress move forward. And who knows, maybe in the near future new LEDs will appear, which will be an order of magnitude higher in terms of characteristics than the existing ones.
We hope our article was useful to the 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 connect an LED correctly
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 the company, are distinguished by high efficiency and cost-effectiveness, which makes it possible to create modern technological and environmentally friendly lighting devices based on them.
So let's decipher the notation a bit.
For example, the lantern says: LED CREE XP-E R2
CREE - naturally the name of the manufacturer of the diode
XR-E, CREE has XP-E, XP-G, other companies have P4, P7, etc. is the designation of the diode itself.
R2 - brightness bin. The bin shows how many lumens an 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. At the moment, 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 in XR-E diodes, R2, R3 are in XP-E, R4-R5 and S2 are only in XP-G.
What is the main difference besides brightness?
The XR-E is the oldest and only found in flashlight models that have been on the market for quite some time. XR-E is very easy to identify outwardly, it has a large hemisphere that covers the diode, the crystal itself is larger than in subsequent series (for comparison, on the XP series it is such a droplet, the size of XP-E compared to XR-E was reduced by 80%. XP -E differs from XP-G in that E has three strips on the diode, G series has four, it turns out that the area of XP-G is higher.
Therefore, in reflectors of the same size, structure, the most long-range 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 at XP-G, not because of the size of the crystal, but because of the difficulty of focusing, more on that below.
If the diodes are arranged in terms of energy efficiency from the weakest to the brightest, then 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 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.
Consider all series. If you shine a lantern on a flat wall, you will see the following artifacts:
At XP-E- an ideal picture without any flaws: a well and evenly focused central beam and even side illumination without dips.
At XP-G when focusing with a reflector, the so-called donut hole can be observed, when the central beam of light is 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 on this type of diodes lose in range to old models on 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 have been built on it! This diode has outstanding characteristics. Its brightness reaches up to 1000 lumens at a current of 3A!
