LEDs for flashlight. types of LEDs for flashlights, brightness. How to choose a powerful rechargeable LED flashlight
Let's consider LED products, ranging from old 5 mm to super-bright high-power LEDs whose power reaches 10 W.
To choose the “right” flashlight for your needs, you need to understand what kinds of LED flashlights there are and their characteristics.
What diodes are used in flashlights?
High-power LED lights started with 5mm sensor devices.
LED flashlights in completely different designs, from pocket to camping, became widespread in the mid-2000s. Their price has dropped noticeably, and the brightness and long term service from one battery charge played a role.
5mm white ultra-bright LEDs consume 20 to 50 mA of current, with a voltage drop of 3.2-3.4 volts. Luminous intensity – 800 mcd.
They perform very well in miniature keychain flashlights. Small size allows you to carry this flashlight with you. They are powered either by “mini-pen” batteries or by several round “tablets”. Often used in flashlight lighters.
These are the types of LEDs that have been installed in Chinese lanterns for many years, but their life is gradually coming to an end.
In search lights when large size reflectors, 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 flashlights with powerful Cree-type LEDs.
Search light with 5mm LEDs These flashlights operate on AA, AAA batteries or rechargeable batteries. They are inexpensive and inferior both in brightness and quality to modern flashlights with more powerful crystals, but more on that below.
IN further development Manufacturers of flashlights have gone through many options, but the market for quality products is occupied by flashlights with powerful matrices or discrete LEDs.
What kind of LEDs are used in high-power flashlights?
Powerful flashlights mean modern flashlights various types ranging from those the size of a finger to huge search lights.
In such products, the Cree brand is relevant in 2017. 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 is LED from the manufacturer Luminus.
Such things are significantly superior to LEDs from Chinese lanterns.
What Cree LEDs are most commonly installed in flashlights?
Models are called consisting of three or 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 carry) range from small flashlights smaller than the palm of your hand to large, serious search flashlights.
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 |
| Illumination 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 luminous flux. The brightness of your flashlight and the amount of light that the source can provide depends on it. Different LEDs, consuming the same amount of energy, can differ significantly in brightness.
Let's look at the characteristics of LEDs in large floodlight flashlights :
| 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 |
| Illumination angle, ° | 115 | 120 | 100 | 90 |
| Color rendering index, Ra | 70-90 | 80-90 | 80-90 |
Sellers often do not indicate 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 flashlight may be called “EDC T6 Flashlight”, there is more than enough information in such brevity.
Flashlight repair
Unfortunately, the price of such flashlights is quite high, as are the diodes themselves. And it is not always possible to purchase a new flashlight in case of a breakdown. Let's figure out how to change the LED in a 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 flashlight; it is usually attached to a threaded connection.
In diode test or resistance measurement mode, check that the LED is working properly. To do this, touch the black and red probes to the LED terminals, first in one position, and then swap the red and black ones.
If the diode is working properly, then in one of the positions there will be low resistance, and in the other - high. This way you determine that the diode is working and conducts current in only one direction. The diode may emit faint light during testing.
Otherwise, there will be a short circuit or high resistance (open) in both positions. Then you need to replace the diode in the flashlight.
Now you need to unsolder the LED from the flashlight and, observing the polarity, solder in a new one. Be careful when choosing an LED, consider its current consumption and the voltage for which it is designed.
If you neglect these parameters, in the best case the flashlight will quickly dry up, in the worst case the driver will fail.
A driver is a device for powering an LED with a stabilized current from different 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 have figured out how to replace the LED in a flashlight and want to upgrade it, before buying heavy-duty models, study the basic principles of LED operation and the limitations in their operation.
Diode matrices do not like overheating - this is the main postulate! And replacing the LED in a flashlight with a more powerful one can lead to this situation. Pay attention to models in which more powerful diodes are installed and compare them with yours; if they are similar in size and design, change them.
If your flashlight is smaller, you will need additional cooling. We wrote more about making radiators with our own hands.
If you try to install such a giant as the Cree MK-R into a miniature keychain flashlight, it will quickly fail from overheating and it will be a waste of money. A slight increase in power (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.
Police lights
LED Police flashlight with shocker Such lanterns 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
The wide range of models is very difficult to cover in one article, but general recommendations for repairs can be given.
- When repairing a flashlight with a stun gun, be careful, preferably use latex gloves to avoid electric shock.
- Flashlights with dust and moisture protection are assembled on a large number of screws. They differ in length, so make notes from where you unscrewed this or that screw.
- Optical system Flashlight Police allows you to adjust the diameter of the light spot. When disassembling the body, make marks on the position in which the parts were before removal, otherwise it will be difficult to put the unit with the lens back.
Replacing the LED, voltage converter unit, driver, and battery is possible using a standard soldering kit.
What kind of LEDs are used in Chinese lanterns?
Many products are now purchased on Aliexpress, where you can find both original products and Chinese copies that do not correspond to the stated description. The price for such devices is comparable to the price of the original.
In a flashlight that claims a Cree LED, it may not actually be there; at best, there will be a diode of a frankly different type, at worst, one that will be difficult to distinguish from the original in appearance.
What might this entail? Cheap LEDs are made in low-tech conditions and do not produce the declared power. They have low efficiency, which is why they have increased heating of the case and crystal. As has already been said, overheating is the worst enemy for LED devices.
This happens because when heated, the current through the semiconductor increases, as a result of which the heating becomes even stronger, the power is released even more, and this avalanche-like leads to breakdown or breakage of the LED.
If you try and spend time searching for information, you can determine the originality of the product.
Compare the original and fake cree LatticeBright is a Chinese LED manufacturer that makes products very similar to Cree, probably a coincidence of design thought (sarcasm).
Comparison Chinese copy and the original Cree On the substrates these clones look like this. You can notice the variety of shapes of LED substrates produced in China.
Detecting counterfeit by LED substrate Counterfeits are made quite skillfully; many sellers do not indicate this “brand” in the product description and where the LEDs for flashlights are made. The quality of such diodes is not the worst among Chinese junk, but it is also far from the original.
Installing an LED instead of an incandescent lamp
Many people have horse races or incandescent lamps collecting dust in old things, and you can easily turn it into LED. For this there is either ready-made solutions, or homemade.
Using a broken light bulb and LEDs, with a little ingenuity and solder, you can make a great replacement.
Iron barrel in in this case needed to improve heat dissipation from the LED. Next you need to solder all the parts to each other and secure 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 unsoldered - a hole will form. Pass the resistor lead through it.
Next you need to solder the free lead of the LED to the base, and the resistor to the central contact. For a voltage of 12 volts, a 500 Ohm resistor is needed, and for a voltage of 5 V – 50-100 Ohms, for power supply from a Li-ion 3.7V battery – 10-25 Ohms.
How to make an LED lamp from an incandescent lamp Selecting 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 dispersion angle to heating of the case.
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!
Understanding what parameters the operation of a flashlight depends on is equally important for those who want to choose a ready-made model and those who want to design a device with their own hands (be it a keychain flashlight with an LED, a pocket, head-mounted or hiking version). Repairing flashlights mainly depends on their design, and replacing some elements requires special skills. Bright is not the only definition for a quality device.
The first step is to identify the purpose of the flashlight. It is hardly possible to highlight universal device, equally effective in any conditions. In the end, a small pocket flashlight can never compare with powerful stationary equipment, and homemade devices are not always superior to ready-made ones (even those made in China), and it’s not just how the LED was selected.
Dimensions
It is necessary to determine the size of the flashlight in 2 cases: to be able to carry it with you (in your pocket, bag, etc.), and to correctly calculate the body when drawing up the diagram yourself.
Dimensions also need to be known when selecting accessories. A headlamp is worn on a special tape, and a hiking lamp is worn on a clip or in a fabric case (on the belt).
Luminous flux parameters
Often, the brightest flashlight is required, but not always a large number of lumens completely determine this indicator. An equally important role is played by the lighting dispersion angle. A simple keychain flashlight with an LED or any pocket version can handle illumination of a small area. The narrower the beam, the further a device can shine, for example, a headlamp for hiking.
Important: The lens can radically change the characteristics of the device. The operation scheme of focusable flashlights is quite simple: the position of the lens adjusts the width and tilt of the beam as it approaches/moves away from the LED.
Selection of the LED itself
It is the light source that determines most of the flashlight's performance (how bright it is). The operation of the device is affected not only by the LED itself, but also by the value of its operating current. The current strength must be taken into account so as not to inadvertently burn the device, because repairing the flashlight is not always appropriate. LEDs and their strings can be grouped in different ways to increase range or coverage area (the largest is usually located closer to the center).
Work offline
Duration of work is a very relative value. It is determined not only by the choice of battery, but also by the flashlight mode, for which the LED is responsible. As for homemade devices, and for ready-made ones, you can install a timer to save energy. Autonomous mode can last for hours (pocket and headlamps) and even days (emergency and search), this period is influenced mainly by the main characteristics.
Types of batteries
Batteries vary depending on the principle of energy generation; among the most popular types are the following:
- lithium (Li-Ion);
- nickel metal hydride (NiMH);
- nickel-cadmium (NiCd);
- lead-acid;
- lithium polymer (Li‑pol);
- nickel-zinc (NiZn).
A small flashlight (pocket or headlamp) can also work on regular AA batteries, in other cases, it is better to select the type of battery based on general requirements so that repairing or replacing the battery does not become an unsolvable task.
Operating modes
The simpler the device, the fewer modes it has in its arsenal. The simplest bright keychain flashlight with an LED, pocket and headlamps, as a rule, have no more than one. The more complex the system, the greater the probability of failure of one of the components, i.e. the more often they require repairs.
Classification of modes:
- brightness (minimum-medium-maximum);
- signal (strobe);
- programmable (manually configured by the user).
Exposure to external factors
The circuit itself and the LED must be protected from shock, shaking, dust and dirt. For more serious devices, it is better to ensure moisture resistance. This can be quite difficult not only when self-assembly, but also after purchasing ready-made models. It is better to check the water resistance in advance, especially on Chinese-made flashlights, in order to be able to carry out repairs in a timely manner.
Mounting location
The flashlight should be easy to use. To do this, you need to think in advance about how the circuit will be drawn up - the location of the buttons responsible for how the LED, auxiliary lenses and diffusers work. It is important to be able to adjust the mount (headlamp or bicycle light), clamping density, etc.
Current stabilization
The operating mode of the LED flashlight directly depends on the supplied current; other characteristics may be similar. Stabilized devices are considered brighter and more stable, but when discharged they quickly go out. An unstabilized flashlight is less bright, but the lamps go out gradually, eventually reducing their brightness to 0.
Having understood the parameters of the device, it becomes much easier not only to select the type of flashlight you are interested in (pocket, head, mounted, keychain flashlight with LED), but also to determine the required elements, if you have your own circuit and selected the appropriate LED, as well as to carry out partial repairs of the device .
The American company CREE is a leading manufacturer of solid-state light sources. The LEDs of the XLamp family of the XR, XP, MC series developed and produced by it are highly efficient and economical, which makes it possible to create modern technologically advanced and environmentally friendly lighting devices on their basis.
So let's decipher the notation a little.
For example, the flashlight says: LED CREE XP-E R2
CREE - naturally the name of the diode manufacturer
XR-E, CREE has XP-E, XP-G, other companies have P4, P7, etc. - this is the designation of the diode itself.
R2 - brightness bin. Bin shows how many lumens the LED produces when consuming 1 watt of energy, for an LED this is a current of 350 mA. IN English language this parameter is called flux bin. Currently there are Q2, Q3, Q4, Q5, R2, R3, R4, R5, S2. The table below shows how many lumens can be obtained from which diode.
Q2-Q5 and R2 are available for XR-E diodes, R2, R3 are available for XP-E, R4-R5 and S2 are only available for XP-G.
What is the main difference other than brightness?
XR-E is the oldest and is found only in flashlight models that have been on the market for quite some time. XR-E is externally very easy to identify, it has a large hemisphere covered by a diode, the crystal itself is larger than that of subsequent series (for comparison on the XP series it is just a droplet, size XP-E compared to the XR-E was reduced by 80%. XP-E differs from XP-G in that the E has three strips on the diode, the G series has four, it turns out that the area of the XP-G is larger.
Consequently, in reflectors of the same size and structure, the longest-range one is XP-E, since it has the smallest crystal, and the smallest light source, since it is easy to focus into a narrow beam, then XR-E, and the widest beam is XP-G, not because of the crystal size, but because of the difficulty of focusing, more on that below.
If the diodes are arranged according to energy efficiency from weakest to brightest, we get XR-E - XP-E - XP-G, where the latter is the most energy efficient, see the table below.
It would seem that if there is the brightest and newest and most efficient XP-G diode, then why are all the well-known and respected flashlight manufacturers in no hurry to switch to this diode. The reason is simple. Each diode requires a specially designed reflector to produce an acceptable light beam.
Let's look at all the series. If you shine a flashlight on a flat wall, you will see the following artifacts:
U XP-E - perfect picture without any drawbacks: a well and evenly focused central beam and smooth side illumination without dips.
U XP-G When focusing using a reflector, a so-called donut hole can be observed, when the central beam of light looks like a donut with a noticeable darkening inside. This is not the fault of the flashlight manufacturers, but a feature of the diode. Therefore, companies such as Fenix, Jetbeam, Nitecore, Zebra, 4sevens were in no hurry to update their lineup, while others, in the race for new products, either installed a highly textured reflector, or simply used reflectors for other types of diodes. All this negatively affects the focusing of the beam and the range of the flashlights. According to many experts, flashlights using this type of diode are inferior in range to older models using XP-E and XR-E.
XM-L- is a real masterpiece of this company! This latest development 2011! Since the invention of this LED, 95% of powerful flashlights are built on it! This diode has outstanding characteristics. Its brightness reaches up to 1000 lumens at a current of 3A!
For safety and the ability to continue active activities in the dark, a person needs artificial lighting. Primitive people pushed back the darkness by setting fire to tree branches, then they came up with a torch and a kerosene stove. And only after the invention of the prototype of a modern battery by the French inventor Georges Leclanche in 1866, and the incandescent lamp in 1879 by Thomson Edison, did David Mizell have the opportunity to patent the first electric flashlight in 1896.
Since then in electrical diagram new samples of flashlights, nothing changed until in 1923 the Russian scientist Oleg Vladimirovich Losev found a connection between luminescence in silicon carbide and the p-n junction, and in 1990 scientists were unable to create an LED with greater luminous efficiency, allowing it to replace an incandescent light bulb. The use of LEDs instead of incandescent lamps, due to the low energy consumption of LEDs, has made it possible to repeatedly increase the operating time of flashlights with the same capacity of batteries and accumulators, increase the reliability of flashlights and practically remove all restrictions on the area of their use.
The LED rechargeable flashlight that you see in the photograph came to me for repair with the complaint that it was purchased the other day chinese lantern Lentel GL01 for $3, does not light up, although the battery charge indicator is on.
The external inspection of the lantern made a positive impression. High-quality casting of the case, comfortable handle and switch. The plug rods for connecting to a household network for charging the battery are made retractable, eliminating the need to store the power cord.
Attention! When disassembling and repairing the flashlight, if it is connected to the network, you should be careful. Touching unprotected parts of your body to uninsulated wires and parts may result in electric shock.
How to disassemble the Lentel GL01 LED rechargeable flashlight
Although the flashlight was subject to warranty repair, but remembering my trips during warranty repairs electric kettle failed (the kettle was expensive and the heating element in it burned out, so it was not possible to repair it with your own hands), I decided to do the repairs myself.
It was easy to disassemble the lantern. It is enough to turn the ring that secures it by a slight angle counterclockwise. protective glass and pull it off, then unscrew a few screws. It turned out that the ring is fixed to the body using a bayonet connection.
After removing one of the halves of the flashlight body, access to all its components appeared. On the left in the photo you can see a printed circuit board with LEDs, to which a reflector (light reflector) is attached using three screws. In the center there is a black battery with unknown parameters; there is only a marking of the polarity of the terminals. To the right of the battery is the printed circuit board charger and indications. Installed on the right mains plug with retractable rods.
Upon closer examination of the LEDs, it turned out that there were black spots or dots on the emitting surfaces of the crystals of all LEDs. It became clear even without checking the LEDs with a multimeter that the flashlight did not light due to their burnout.
There were also blackened areas on the crystals of two LEDs installed as backlight on the battery charging indication board. In LED lamps and strips, one LED usually fails, and acting as a fuse, it protects the others from burning out. And all nine LEDs in the flashlight failed at the same time. The voltage on the battery could not increase to a value that could damage the LEDs. To find out the reason, I had to draw an electrical circuit diagram.
Finding the cause of the flashlight failure
The electrical circuit of the flashlight consists of two functionally complete parts. The part of the circuit located to the left of switch SA1 acts as a charger. And the part of the circuit shown to the right of the switch provides the glow.
The charger works as follows. The voltage from the 220 V household network is supplied to the current-limiting capacitor C1, then to a bridge rectifier assembled on diodes VD1-VD4. From the rectifier, voltage is supplied to the battery terminals. Resistor R1 serves to discharge the capacitor after removing the flashlight plug from the network. This prevents electric shock from capacitor discharge in the event of your hand accidentally touching two pins of the plug at the same time.
LED HL1 connected in series with current-limiting resistor R2 in opposite direction with the upper right diode of the bridge, as it turned out, always lights up when the plug is inserted into the network, even if the battery is faulty or disconnected from the circuit.
The operating mode switch SA1 is used to connect separate groups of LEDs to the battery. As you can see from the diagram, it turns out that if the flashlight is connected to the network for charging and the switch slide is in position 3 or 4, then the voltage from the battery charger also goes to the LEDs.
If a person turns on the flashlight and discovers that it does not work, and, not knowing that the switch slide must be set to the “off” position, about which nothing is said in the flashlight’s operating instructions, connects the flashlight to the network for charging, then at the expense If there is a voltage surge at the output of the charger, the LEDs will receive a voltage significantly higher than the calculated one. A current that exceeds the permissible current will flow through the LEDs and they will burn out. As an acid battery ages due to sulfation of the lead plates, the battery charge voltage increases, which also leads to LED burnout.
Another circuit design What surprised me was the parallel connection of seven LEDs, which is unacceptable, since the current-voltage characteristics of even LEDs of the same type are different and therefore the current passing through the LEDs will also not be the same. For this reason, when choosing the value of resistor R4 based on the maximum permissible current flowing through the LEDs, one of them may overload and fail, and this will lead to an overcurrent of parallel-connected LEDs, and they will also burn out.
Rework (modernization) of the electrical circuit of the flashlight
It became obvious that the failure of the flashlight was due to errors made by the developers of its electrical circuit diagram. To repair the lantern and eliminate it repeated breakdown it is necessary to redo it, replacing the LEDs and making minor changes to the electrical circuit.
In order for the battery charge indicator to actually signal that it is charging, the HL1 LED must be connected in series with the battery. To light an LED, a current of several milliamps is required, and the current supplied by the charger should be about 100 mA.
To ensure these conditions, it is enough to disconnect the HL1-R2 chain from the circuit in the places indicated by red crosses and install an additional resistor Rd with a nominal value of 47 Ohms and a power of at least 0.5 W in parallel with it. The charge current flowing through Rd will create a voltage drop of about 3 V across it, which will provide the necessary current for the HL1 indicator to light. At the same time, the connection point between HL1 and Rd must be connected to pin 1 of switch SA1. In this simple way, it will be impossible to supply voltage from the charger to the LEDs EL1-EL10 while charging the battery.
To equalize the magnitude of the currents flowing through the LEDs EL3-EL10, it is necessary to exclude resistor R4 from the circuit and connect a separate resistor with a nominal value of 47-56 Ohms in series with each LED.
Electrical diagram after modification
Minor changes made to the circuit increased the information content of the charge indicator of an inexpensive Chinese LED flashlight and greatly increased its reliability. I hope that LED flashlight manufacturers will make changes to the electrical circuits of their products after reading this article.
After modernization, electrical circuit diagram took the form as in the drawing above. If you need to illuminate the flashlight for a long time and do not require high brightness of its glow, you can additionally install a current-limiting resistor R5, thanks to which the operating time of the flashlight without recharging will double.
LED battery flashlight repair
After disassembly, the first thing you need to do is restore the functionality of the flashlight, and then start upgrading it.
Checking the LEDs with a multimeter confirmed that they were faulty. Therefore, all the LEDs had to be desoldered and the holes freed from solder to install new diodes.
Judging by its appearance, the board was equipped with tube LEDs from the HL-508H series with a diameter of 5 mm. LEDs of type HK5H4U from a linear LED lamp with similar technical characteristics were available. They came in handy for repairing the lantern. When soldering LEDs to the board, you must remember to observe polarity; the anode must be connected to the positive terminal of the battery or battery.
After replacing the LEDs, the PCB was connected to the circuit. The brightness of some LEDs was slightly different from others due to the common current-limiting resistor. To eliminate this drawback, it is necessary to remove resistor R4 and replace it with seven resistors, connected in series with each LED.
To select a resistor that ensures optimal operation of the LED, the dependence of the current flowing through the LED on the value of the series-connected resistance was measured at a voltage of 3.6 V, equal to the voltage of the flashlight battery.
Based on the conditions for using the flashlight (in case of interruptions in the power supply to the apartment), high brightness and illumination range were not required, so the resistor was chosen with a nominal value of 56 Ohms. With such a current-limiting resistor, the LED will operate in easy mode, and energy consumption will be economical. If you need to squeeze out maximum brightness from the flashlight, then you should use a resistor, as can be seen from the table, with a nominal value of 33 Ohms and make two modes of operation of the flashlight by turning on another common current-limiting resistor (in the diagram R5) with a nominal value of 5.6 Ohms.
To connect a resistor in series with each LED, you must first prepare the printed circuit board. To do this, you need to cut any one current-carrying path on it, suitable for each LED, and make additional contact pads. The current-carrying paths on the board are protected by a layer of varnish, which must be scraped off with a knife blade to the copper, as in the photograph. Then tin the bare contact pads with solder.
It is better and more convenient to prepare a printed circuit board for mounting resistors and soldering them if the board is mounted on a standard reflector. In this case, the surface of the LED lenses will not be scratched, and it will be more convenient to work.
Connecting the diode board after repair and modernization to the flashlight battery showed that the brightness of all LEDs was sufficient for illumination and the same brightness.
Before I had time to repair the previous lamp, a second one was repaired, with the same fault. I didn’t find any information about the manufacturer or technical specifications on the flashlight body, but judging by the manufacturing style and the cause of the breakdown, the manufacturer is the same, Chinese Lentel.
Based on the date on the flashlight body and on the battery, it was possible to establish that the flashlight was already four years old and, according to its owner, the flashlight worked flawlessly. It is obvious that the flashlight lasted a long time thanks to the warning sign “Do not turn on while charging!” on a hinged lid covering a compartment in which a plug is hidden for connecting the flashlight to the mains for charging the battery.
In this flashlight model, the LEDs are included in the circuit according to the rules; a 33 Ohm resistor is installed in series with each one. The resistor value can be easily determined by color coding using an online calculator. A check with a multimeter showed that all the LEDs were faulty, and the resistors were also broken.
An analysis of the cause of the failure of the LEDs showed that due to sulfation of the acid battery plates, its internal resistance increased and, as a result, its charging voltage increased several times. During charging, the flashlight was turned on, the current through the LEDs and resistors exceeded the limit, which led to their failure. I had to replace not only the LEDs, but also all the resistors. Based on the above-mentioned operating conditions of the flashlight, resistors with a nominal value of 47 Ohms were chosen for replacement. The resistor value for any type of LED can be calculated using an online calculator.
Redesign of the battery charging mode indication circuit
The flashlight has been repaired, and you can begin making changes to the battery charging indication circuit. To do this, it is necessary to cut the track on the printed circuit board of the charger and indication in such a way that the HL1-R2 chain on the LED side is disconnected from the circuit.
The lead-acid AGM battery has been upgraded to deep discharge, and an attempt to charge it with a standard charger was unsuccessful. I had to charge the battery using stationary unit power supply with load current limiting function. A voltage of 30 V was applied to the battery, and at the first moment it consumed only a few mA of current. Over time, the current began to increase and after a few hours increased to 100 mA. After fully charged The battery was installed in the flashlight.
Charging deeply discharged lead-acid AGM batteries as a result of long-term storage increased voltage allows you to restore their functionality. I have tested the method on AGM batteries more than a dozen times. New batteries that do not want to be charged from standard chargers, when charging from permanent source at a voltage of 30 V they are restored almost to their original capacity.
The battery was discharged several times by turning on the flashlight in operating mode and charged using a standard charger. The measured charge current was 123 mA, with a voltage at the battery terminals of 6.9 V. Unfortunately, the battery was worn out and was enough to operate the flashlight for 2 hours. That is, the battery capacity was about 0.2 A×hour and for long work The lamp needs to be replaced.
The HL1-R2 chain on the printed circuit board was successfully placed, and it was necessary to cut only one current-carrying path at an angle, as in the photograph. The cutting width must be at least 1 mm. Calculation of the resistor value and testing in practice showed that for stable operation of the battery charging indicator, a 47 Ohm resistor with a power of at least 0.5 W is required.
The photo shows a printed circuit board with a soldered current-limiting resistor. After this modification, the battery charge indicator lights up only if the battery is actually charging.
Modernization of the operating mode switch
To complete the repair and modernization of the lights, it is necessary to resolder the wires at the switch terminals.
In models of flashlights being repaired, a four-position slide-type switch is used to turn on. The middle pin in the photo shown is general. When the switch slide is in the extreme left position, the common terminal is connected to the left terminal of the switch. When moving the switch slide from the extreme left position to one position to the right, its common pin is connected to the second pin and, with further movement of the slide, sequentially to pins 4 and 5.
To the middle common terminal (see photo above) you need to solder a wire coming from the positive terminal of the battery. Thus, it will be possible to connect the battery to a charger or LEDs. To the first pin you can solder a wire coming from the main board with LEDs, to the second you can solder a current-limiting resistor R5 of 5.6 Ohms to be able to switch the flashlight to energy saving mode work. Solder the conductor coming from the charger to the rightmost pin. This will prevent you from turning on the flashlight while the battery is charging.
Repair and modernization
LED rechargeable spotlight "Foton PB-0303"
I received another copy of a series of Chinese-made LED flashlights called the Photon PB-0303 LED spotlight for repair. The flashlight did not respond when the power button was pressed; an attempt to charge the flashlight battery using a charger was unsuccessful.
The flashlight is powerful, expensive, costs about $20. According to the manufacturer, the luminous flux of the flashlight reaches 200 meters, the body is made of impact-resistant ABS plastic, and the kit includes a separate charger and a shoulder strap.
The Photon LED flashlight has good maintainability. To gain access to the electrical circuit, simply unscrew the plastic ring holding the protective glass, rotating the ring counterclockwise when looking at the LEDs.
When repairing any electrical appliances, troubleshooting always starts with the power source. Therefore, the first step was to measure the voltage at the terminals of the acid battery using a multimeter turned on in mode. It was 2.3 V, instead of the required 4.4 V. The battery was completely discharged.
When connecting the charger, the voltage at the battery terminals did not change, it became obvious that the charger was not working. The flashlight was used until the battery was completely discharged, and then it was not used for a long time, which led to a deep discharge of the battery.
It remains to check the serviceability of the LEDs and other elements. To do this, the reflector was removed, for which six screws were unscrewed. On the printed circuit board there were only three LEDs, a chip (chip) in the form of a droplet, a transistor and a diode.
Five wires went from the board and battery into the handle. In order to understand their connection, it was necessary to disassemble it. To do this, use a Phillips screwdriver to unscrew the two screws inside the flashlight, which were located next to the hole into which the wires went.
To detach the flashlight handle from its body, it must be moved away from the mounting screws. This must be done carefully so as not to tear the wires off the board.
As it turned out, there were no radio-electronic elements in the pen. Two white wires were soldered to the terminals of the flashlight on/off button, and the rest to the connector for connecting the charger. A red wire was soldered to pin 1 of the connector (the numbering is conditional), the other end of which was soldered to the positive input of the printed circuit board. A blue-white conductor was soldered to the second contact, the other end of which was soldered to the negative pad of the printed circuit board. A green wire was soldered to pin 3, the second end of which was soldered to the negative terminal of the battery.
Electrical circuit diagram
Having dealt with the wires hidden in the handle, you can draw an electrical circuit diagram of the Photon flashlight.
From the negative terminal of the battery GB1, voltage is supplied to pin 3 of connector X1 and then from its pin 2 through a blue-white conductor it is supplied to the printed circuit board.
Connector X1 is designed in such a way that when the charger plug is not inserted into it, pins 2 and 3 are connected to each other. When the plug is inserted, pins 2 and 3 are disconnected. This ensures automatic disconnection of the electronic part of the circuit from the charger, eliminating the possibility of accidentally turning on the flashlight while charging the battery.
From the positive terminal of battery GB1, voltage is supplied to D1 (microcircuit-chip) and the emitter of a bipolar transistor type S8550. The CHIP performs only the function of a trigger, allowing a button to turn on or off the glow of EL LEDs (⌀8 mm, glow color - white, power 0.5 W, current consumption 100 mA, voltage drop 3 V.). When you first press the S1 button from the D1 chip, a positive voltage is applied to the base of the transistor Q1, it opens and the supply voltage is supplied to the LEDs EL1-EL3, the flashlight turns on. When you press button S1 again, the transistor closes and the flashlight turns off.
From a technical point of view, such a circuit solution is illiterate, since it increases the cost of the flashlight, reduces its reliability, and in addition, due to the voltage drop at the junction of transistor Q1, up to 20% of the battery capacity is lost. This circuit solution is justified if it is possible to adjust the brightness light beam. In this model, instead of a button, it was enough to install a mechanical switch.
It was surprising that in the circuit, LEDs EL1-EL3 are connected in parallel to the battery like incandescent light bulbs, without current-limiting elements. As a result, when turned on, a current passes through the LEDs, the magnitude of which is limited only internal resistance battery and when it is fully charged, the current may exceed the permissible value for the LEDs, which will lead to their failure.
Checking the functionality of the electrical circuit
To check the serviceability of the microcircuit, transistor and LEDs from external source The current limiting power supply was supplied with correct polarity at 4.4 VDC directly to the PCB power pins. The current limit value was set to 0.5 A.
After pressing the power button, the LEDs lit up. After pressing again, they went out. The LEDs and the microcircuit with the transistor turned out to be serviceable. All that remains is to figure out the battery and charger.
Acid battery recovery
Since the acid-acid battery with a capacity of 1.7 A was completely discharged, and the standard charger was faulty, I decided to charge it from a stationary power supply. When connecting the battery for charging to a power supply with a set voltage of 9 V, the charging current was less than 1 mA. The voltage was increased to 30 V - the current increased to 5 mA, and after an hour at this voltage it was already 44 mA. Next, the voltage was reduced to 12 V, the current dropped to 7 mA. After 12 hours of charging the battery at a voltage of 12 V, the current rose to 100 mA, and the battery was charged with this current for 15 hours.
The temperature of the battery case was within normal limits, indicating that the current charging in progress not for the release of heat, but for the accumulation of energy. After charging the battery and finalizing the circuit, which will be discussed below, tests were carried out. The flashlight with a restored battery illuminated continuously for 16 hours, after which the brightness of the beam began to decrease and therefore it was turned off.
Using the method described above, I had to repeatedly restore the functionality of deeply discharged small-sized acid batteries. As practice has shown, only serviceable batteries that have been forgotten for some time can be restored. Acid batteries that have exhausted their service life cannot be restored.
Charger repair
Measuring the voltage value with a multimeter at the contacts of the output connector of the charger showed its absence.
Judging by the sticker pasted on the adapter body, it was a power supply that produced an unstabilized constant pressure 12 V with a maximum load current of 0.5 A. There were no elements in the electrical circuit that limited the amount of charging current, so the question arose, why was an ordinary power supply used as a charger?
When the adapter was opened, a characteristic smell of burnt electrical wiring appeared, which indicated that the transformer winding had burned out.
A continuity test of the primary winding of the transformer showed that it was broken. After cutting the first layer of tape insulating the primary winding of the transformer, a thermal fuse was discovered, designed for an operating temperature of 130°C. Testing showed that both the primary winding and the thermal fuse were faulty.
Repairing the adapter was not economically feasible, since it was necessary to rewind the primary winding of the transformer and install a new thermal fuse. I replaced it with a similar one that was on hand, with a DC voltage of 9 V. The flexible cord with a connector had to be resoldered from a burnt adapter.
The photo shows a drawing of the electrical circuit of a burnt-out power supply (adapter) of the Photon LED flashlight. The replacement adapter was assembled according to the same scheme, only with an output voltage of 9 V. This voltage is quite sufficient to provide the required battery charging current with a voltage of 4.4 V.
Just for fun, I connected the flashlight to a new power supply and measured the charging current. Its value was 620 mA, and this was at a voltage of 9 V. At a voltage of 12 V, the current was about 900 mA, significantly exceeding the load capacity of the adapter and the recommended battery charging current. For this reason, the primary winding of the transformer burned out due to overheating.
Finalization of the electrical circuit diagram
LED rechargeable flashlight "Photon"
To eliminate circuit violations in order to ensure reliable and long-term operation, changes were made to the flashlight circuit and the printed circuit board was modified.
The photo shows the electrical circuit diagram of the converted Photon LED flashlight. Additional installed radio elements are shown in blue. Resistor R2 limits the battery charging current to 120 mA. To increase the charging current, you need to reduce the resistor value. Resistors R3-R5 limit and equalize the current flowing through the LEDs EL1-EL3 when the flashlight is illuminated. The EL4 LED with a series-connected current-limiting resistor R1 is installed to indicate the battery charging process, since the developers of the flashlight did not take care of this.
To install current-limiting resistors on the board, the printed traces were cut, as shown in the photo. The charge current-limiting resistor R2 was soldered at one end to the contact pad, to which the positive wire coming from the charger had previously been soldered, and the soldered wire was soldered to the second terminal of the resistor. An additional wire was soldered to the same contact pad (in the picture yellow color), designed to connect a battery charging indicator.
Resistor R1 and indicator LED EL4 were placed in the flashlight handle, next to the connector for connecting the charger X1. The LED anode pin was soldered to pin 1 of connector X1, and a current-limiting resistor R1 was soldered to the second pin, the cathode of the LED. A wire (yellow in the photo) was soldered to the second terminal of the resistor, connecting it to the terminal of resistor R2, soldered to the printed circuit board. Resistor R2, for ease of installation, could have been placed in the flashlight handle, but since it heats up when charging, I decided to place it in a freer space.
When finalizing the circuit, MLT type resistors with a power of 0.25 W were used, except for R2, which is designed for 0.5 W. The EL4 LED is suitable for any type and color of light.
This photo shows the charging indicator while the battery is charging. Installing an indicator made it possible not only to monitor the battery charging process, but also to monitor the presence of voltage in the network, the health of the power supply and the reliability of its connection.
How to replace a burnt out CHIP
If suddenly a CHIP - a specialized unmarked microcircuit in a Photon LED flashlight, or a similar one assembled according to a similar circuit - fails, then to restore the flashlight's functionality it can be successfully replaced with a mechanical switch.
To do this, you need to remove the D1 chip from the board, and instead of the Q1 transistor switch, connect an ordinary mechanical switch, as shown in the above electrical diagram. The switch on the flashlight body can be installed instead of the S1 button or in any other suitable place.
Repair and alteration of LED flashlight
14Led Smartbuy Colorado
Stopped turning on LED flashlight Smartbuy Colorado, although three AAA batteries were installed new.
The waterproof body was made of anodized aluminum alloy and had a length of 12 cm. The flashlight looked stylish and was easy to use.
How to check batteries for suitability in an LED flashlight
Repair of any electrical device begins with checking the power source, therefore, despite the fact that new batteries were installed in the flashlight, repairs should begin with checking them. In the Smartbuy flashlight, the batteries are installed in a special container, in which they are connected in series using jumpers. In order to gain access to the flashlight batteries, you need to disassemble it by rotating the back cover counterclockwise.
Batteries must be installed in the container, observing the polarity indicated on it. The polarity is also indicated on the container, so it must be inserted into the flashlight body with the side on which the “+” sign is marked.
First of all, it is necessary to visually check all contacts of the container. If there are traces of oxides on them, then the contacts must be cleaned to a shine using sandpaper or the oxide must be scraped off with a knife blade. To prevent re-oxidation of the contacts, they can be lubricated with a thin layer of any machine oil.
Next you need to check the suitability of the batteries. To do this, touching the probes of a multimeter turned on in DC voltage measurement mode, you need to measure the voltage at the contacts of the container. Three batteries are connected in series and each of them should produce a voltage of 1.5 V, therefore the voltage at the terminals of the container should be 4.5 V.
If the voltage is less than specified, then it is necessary to check the correct polarity of the batteries in the container and measure the voltage of each of them individually. Perhaps only one of them sat down.
If everything is in order with the batteries, then you need to insert the container into the flashlight body, observing the polarity, screw on the cap and check its functionality. In this case, you need to pay attention to the spring in the cover, through which the supply voltage is transmitted to the flashlight body and from it directly to the LEDs. There should be no traces of corrosion on its end.
How to check if the switch is working properly
If the batteries are good and the contacts are clean, but the LEDs do not light, then you need to check the switch.
The Smartbuy Colorado flashlight has a sealed push-button switch with two fixed positions, closing the wire coming from the positive terminal of the battery container. When you press the switch button for the first time, its contacts close, and when you press it again, they open.
Since the flashlight contains batteries, you can also check the switch using a multimeter turned on in voltmeter mode. To do this, you need to rotate it counterclockwise, if you look at the LEDs, unscrew its front part and put it aside. Next, touch the flashlight body with one multimeter probe, and the second one to the contact, which is located deep in the center of the plastic part shown in the photo.
The voltmeter should show a voltage of 4.5 V. If there is no voltage, press the switch button. If it is working properly, then voltage will appear. Otherwise, the switch needs to be repaired.
Checking the health of the LEDs
If the previous search steps failed to detect a fault, then at the next stage you need to check the reliability of the contacts supplying the supply voltage to the board with LEDs, the reliability of their soldering and serviceability.
A printed circuit board with LEDs sealed into it is fixed in the head of the flashlight using a steel spring-loaded ring, through which the supply voltage from the negative terminal of the battery container is simultaneously supplied to the LEDs along the flashlight body. The photo shows the ring from the side it presses against the printed circuit board.
The retaining ring is fixed quite tightly, and it was only possible to remove it using the device shown in the photo. You can bend such a hook from a steel strip with your own hands.
After removing the retaining ring, the printed circuit board with LEDs, which is shown in the photo, was easily removed from the head of the flashlight. The absence of current-limiting resistors immediately caught my eye; all 14 LEDs were connected in parallel and directly to the batteries via a switch. Connecting LEDs directly to a battery is unacceptable, since the amount of current flowing through the LEDs is limited only by the internal resistance of the batteries and can damage the LEDs. At best, it will greatly reduce their service life.
Since all the LEDs in the flashlight were connected in parallel, it was not possible to check them with a multimeter turned on in resistance measurement mode. Therefore, the printed circuit board was supplied with a DC supply voltage from an external source of 4.5 V with a current limit of 200 mA. All LEDs lit up. It became obvious that the problem with the flashlight was poor contact between the printed circuit board and the retaining ring.
Current consumption of LED flashlight
For fun, I measured the current consumption of LEDs from batteries when they were turned on without a current-limiting resistor.
The current was more than 627 mA. The flashlight is equipped with LEDs of type HL-508H, the operating current of which should not exceed 20 mA. 14 LEDs are connected in parallel, therefore, the total current consumption should not exceed 280 mA. Thus, the current flowing through the LEDs more than doubled the rated current.
Such a forced mode of LED operation is unacceptable, as it leads to overheating of the crystal, and as a result, premature failure of the LEDs. An additional disadvantage is that the batteries drain quickly. They will be enough, if the LEDs do not burn out first, for no more than an hour of operation.
The design of the flashlight did not allow soldering current-limiting resistors in series with each LED, so we had to install one common one for all LEDs. The resistor value had to be determined experimentally. To do this, the flashlight was powered by pants batteries and an ammeter was connected to the gap in the positive wire in series with a 5.1 Ohm resistor. The current was about 200 mA. When installing an 8.2 Ohm resistor, the current consumption was 160 mA, which, as tests showed, is quite sufficient for good lighting at a distance of at least 5 meters. The resistor did not get hot to the touch, so Any will do power.
Redesign of the structure
After the study, it became obvious that for reliable and durable operation of the flashlight, it is necessary to additionally install a current-limiting resistor and duplicate the connection of the printed circuit board with the LEDs and the fixing ring with an additional conductor.
If previously it was necessary for the negative bus of the printed circuit board to touch the body of the flashlight, then due to the installation of the resistor, it was necessary to eliminate the contact. To do this, a corner was ground off from the printed circuit board along its entire circumference, from the side of the current-carrying paths, using a needle file.
To prevent the clamping ring from touching the current-carrying tracks when fixing the printed circuit board, four rubber insulators about two millimeters thick were glued onto it with Moment glue, as shown in the photograph. Insulators can be made from any dielectric material, such as plastic or thick cardboard.
The resistor was pre-soldered to the clamping ring, and a piece of wire was soldered to the outermost track of the printed circuit board. An insulating tube was placed over the conductor, and then the wire was soldered to the second terminal of the resistor.
After simply upgrading the flashlight with your own hands, it began to turn on stably and the light beam illuminated objects well at a distance of more than eight meters. Additionally, the battery life has more than tripled, and the reliability of the LEDs has increased many times over.
An analysis of the causes of failure of repaired Chinese LED lights showed that they all failed due to poorly designed electrical circuits. It remains only to find out whether this was done intentionally in order to save on components and shorten the life of the flashlights (so that more people would buy new ones), or as a result of the illiteracy of the developers. I am inclined to the first assumption.
Repair of LED flashlight RED 110
A flashlight with a built-in acid battery was repaired Chinese manufacturer trademark RED. The flashlight had two emitters: one with a beam in the form of a narrow beam and one emitting diffused light.
The photo shows the appearance of the RED 110 flashlight. I immediately liked the flashlight. Convenient body shape, two modes of operation, a loop for hanging around the neck, a retractable plug for connecting to the mains for charging. In the flashlight, the diffused light LED section was shining, but the narrow beam was not.
To make the repair, we first unscrewed the black ring securing the reflector, and then unscrewed one self-tapping screw in the hinge area. The case easily separated into two halves. All parts were secured with self-tapping screws and were easily removed.
The charger circuit was made according to the classical scheme. From the network through a current-limiting capacitor with a capacity of 1 μF, voltage was supplied to rectifier bridge from four diodes and then to the battery terminals. The voltage from the battery to the narrow beam LED was supplied through a 460 Ohm current limiting resistor.
All parts were mounted on a single-sided printed circuit board. The wires were soldered directly to the contact pads. The appearance of the printed circuit board is shown in the photograph.
10 side light LEDs were connected in parallel. The supply voltage was supplied to them through a common current-limiting resistor 3R3 (3.3 Ohms), although according to the rules, a separate resistor must be installed for each LED.
During an external inspection of the narrow beam LED, no defects were found. When power was supplied through the flashlight switch from the battery, voltage was present at the LED terminals, and it heated up. It became obvious that the crystal was broken, and this was confirmed by a continuity test with a multimeter. The resistance was 46 ohms for any connection of the probes to the LED terminals. The LED was faulty and needed to be replaced.
For ease of operation, the wires were unsoldered from the LED board. After freeing the LED leads from the solder, it turned out that the LED was tightly held by the entire plane of the reverse side on the printed circuit board. To separate it, we had to fix the board in the desktop temples. Next, place the sharp end of the knife at the junction of the LED and the board and lightly hit the knife handle with a hammer. The LED bounced off.
As usual, there were no markings on the LED housing. Therefore, it was necessary to determine its parameters and select a suitable replacement. Based on the overall dimensions of the LED, the battery voltage and the size of the current-limiting resistor, it was determined that a 1 W LED (current 350 mA, voltage drop 3 V) would be suitable for replacement. From the “Reference Table of Parameters of Popular SMD LEDs,” a white LED6000Am1W-A120 LED was selected for repair.
The printed circuit board on which the LED is installed is made of aluminum and at the same time serves to remove heat from the LED. Therefore, when installing it, it is necessary to ensure good thermal contact due to the tight fit of the rear plane of the LED to the printed circuit board. To do this, before sealing, thermal paste was applied to the contact areas of the surfaces, which is used when installing a radiator on a computer processor.
In order to ensure a tight fit of the LED plane to the board, you must first place it on the plane and slightly bend the leads upward so that they deviate from the plane by 0.5 mm. Next, tin the terminals with solder, apply thermal paste and install the LED on the board. Next, press it to the board (it’s convenient to do this with a screwdriver with the bit removed) and warm up the leads with a soldering iron. Next, remove the screwdriver, press it with a knife at the bend of the lead to the board and heat it with a soldering iron. After the solder has hardened, remove the knife. Due to the spring properties of the leads, the LED will be pressed tightly to the board.
When installing the LED, polarity must be observed. True, in this case, if a mistake is made, it will be possible to swap the voltage supply wires. The LED is soldered and you can check its operation and measure the current consumption and voltage drop.
The current flowing through the LED was 250 mA, the voltage drop was 3.2 V. Hence the power consumption (you need to multiply the current by the voltage) was 0.8 W. It was possible to increase the operating current of the LED by decreasing the resistance to 460 Ohms, but I did not do this, since the brightness of the glow was sufficient. But the LED will operate in a lighter mode, heat up less, and the flashlight’s operating time on a single charge will increase.
Checking the heating of the LED after operating for an hour showed effective heat dissipation. It heated up to a temperature of no more than 45°C. Sea trials showed a sufficient illumination range in the dark, more than 30 meters.
Replacing a lead acid battery in an LED flashlight
A failed acid battery in an LED flashlight can be replaced with either a similar acid battery or a lithium-ion (Li-ion) or nickel-metal hydride (Ni-MH) AA or AAA battery.
The Chinese lanterns being repaired were equipped with lead-acid AGM batteries of various sizes without markings with a voltage of 3.6 V. According to calculations, the capacity of these batteries ranges from 1.2 to 2 A×hours.
On sale you can find a similar acid battery from a Russian manufacturer for the 4V 1Ah Delta DT 401 UPS, which has an output voltage of 4 V with a capacity of 1 Ah, costing a couple of dollars. To replace it, simply re-solder the two wires, observing the polarity.
After several years of operation, the Lentel GL01 LED flashlight, the repair of which was described at the beginning of the article, was again brought to me for repair. Diagnostics showed that the acid battery had exhausted its service life.
A Delta DT 401 battery was purchased as a replacement, but it turned out that its geometric dimensions were larger than the faulty one. The standard flashlight battery had dimensions of 21x30x54 mm and was 10 mm higher. I had to modify the flashlight body. Therefore, before buying a new battery, make sure that it will fit into the flashlight body.
The stop in the case was removed and a part of the printed circuit board from which a resistor and one LED had previously been soldered off was cut off with a hacksaw.
After modification, the new battery installed well in the flashlight body and now, I hope, will last for many years.
Replacing a lead acid battery
AA or AAA batteries
If it is not possible to purchase a 4V 1Ah Delta DT 401 battery, then it can be successfully replaced with any three AA or AAA size AA or AAA pen-type batteries, which have a voltage of 1.2 V. For this, it is enough connect three batteries in series, observing polarity, using soldering wires. However, such a replacement is not economically feasible, since the cost of three high-quality AA batteries size AA may exceed the cost of purchasing a new LED flashlight.
But where is the guarantee that there are no errors in the electrical circuit of the new LED flashlight, and it will not have to be modified either. Therefore, I believe that replacing the lead battery in a modified flashlight is advisable, since it will provide reliable operation the lantern is still a few years away. And it will always be a pleasure to use a flashlight that you have repaired and modernized yourself.
The modern lighting market offers huge selection lighting devices with narrow scattering angles and a long range. These are spotlights general purpose, spotlights for transport, theater stages, studios, construction sites, airfields and many others. Such lighting devices also include powerful battery-powered flashlights.
When choosing the most suitable, modern and effective flashlight, you may immediately become confused, since with all the variety of their designs, types of light sources used, range and beam scattering angle and other parameters, it is difficult to immediately settle on a specific model.
In this article we will try to understand the most important technical features of flashlights that influence the correctness of their choice.
The purpose of powerful flashlights
Powerful flashlights designed for use in difficult conditions, where a stable, bright luminous flux is required, the maintenance of which is ensured over a long period of time. Most often they are used in their work by rescue services, employees of the Ministry of Internal Affairs, speleologists and tourists. Typical representatives of this class of lighting devices are search or tactical flashlights. Also powerful are under-barrel flashlights, which are attached under the barrel of a weapon using special fasteners, camping flashlights or those that have a long operating time, headlamps or headlamps, the fastening of which allows you to attach them to your head. Therefore, when choosing a powerful flashlight, you should always pay attention to what purpose it is intended for.
The special conditions in which powerful flashlights are usually used dictate special requirements for their design and light characteristics. Namely:
- shock resistance and moisture resistance of the case;
- the presence in lanterns of materials with high thermal conductivity, ensuring effective heat removal from the light source;
- battery capacity, the value of which directly affects the duration of the flashlight and its stability luminous flux;
- universal design of the container for installing batteries;
- possibility of adjusting the angle of dispersion of the light flux;
- the reliability of special fastenings, the effectiveness of anti-slip inserts or notches on the handle of the flashlight, the presence of a strap for carrying the flashlight on the shoulder and other nuances.
Body material and handle design
Since it so happens that search lights are the most popular on the market, we will take a look at them as an example.
For the manufacture of the body of modern powerful search lamps, anodized duralumin is often used, lightweight, durable and corrosion-resistant, on the outer surface of which either anti-slip polyurethane coating is applied, resistant to scratches and impacts, or longitudinal, transverse and diagonal notches. The body of such flashlights is mostly made in the form of a tube that simultaneously performs two functions - a handle and a container for batteries. But there are flashlights with a remote handle. Examples of cases and handles can be seen in the images below.
The images also clearly show the radiator fins, which increase the efficiency of heat removal from the light source. The ribs are made by turning the body metal mass closer to the optical part of the flashlight.
Waterproof
Flashlights have different degrees of protection against foreign objects and moisture getting inside their housing. Since all flashlights have minimal protection capable of trapping dust particles, but are not able to work when they are exposed to drops and splashes of water for a long time, they can be divided into two groups: non-moisture-resistant and moisture-resistant flashlights. According to the classification system for degrees of protection (IP - Ingress Protection Rating), non-moisture resistant ones can be assigned the value IP50, that is, dust-proof and moisture-permeable. Housings for moisture-resistant flashlights are usually produced with the ability to immerse all flashlights under water. Therefore, their degree of protection starts from IP67 and ends with IP69. Sometimes the number indicating the penetration of foreign objects is omitted and the letter “X” is placed instead of the first number (IPХ7 - IPХ9).
Let's decipher the meaning of numbers 7 - 9. Number 7 indicates the possibility of briefly immersing the flashlight to a depth of up to 1 meter. The number 8 indicates the possibility of long-term immersion of the flashlight to a depth of more than 1 meter. The number 9 indicates the possibility of long-term immersion of the flashlight to a very great depth, where there is high fluid pressure.
Sources of light
The light source is perhaps the most important element that characterizes the consumer and operational parameters of flashlights. Conventional incandescent lamps are becoming a thing of the past and are no longer used in modern powerful flashlights. Modern high-power flashlights use halogen incandescent lamps, xenon discharge lamps (HID) and light-emitting diodes (LED) as light sources.
Halogen lamps
This is an improved type of incandescent lamps and we can only talk about their advantages in comparison with traditional options. Filling the bulb of an incandescent lamp with halogen additives made it possible to increase its luminous efficiency at the same power and extend its service life by half (up to 2000 hours) by reducing tungsten burnout.
The lamps have an average light output of 22 Lm/W. This is almost twice as high as a conventional incandescent lamp, but it is still very low considering that the lamp must be operated in a portable flashlight and the energy source has a limited resource. The lamps are very sensitive to frequent switching on, at which they basically burn out.
Like ordinary lamps incandescent lamps are becoming a thing of the past, because they find it difficult to compete with durable and energy-efficient LED and xenon light sources.
Xenon lamps
A characteristic feature of xenon lamps is that the electrical discharge of the lamp occurs in the inert gas xenon, at high pressure and high current densities. For this reason, lamps have very high brightness And visible spectrum radiation close to sunlight With color temperature 6100 - 6300 K.
Xenon lamps have high voltage ignition and therefore require the use of special ignition devices. After ignition, the lamps light up within approximately 15 seconds.
Xenon lamps are very sensitive to changes in supply voltage. When the supply voltage changes by ±5%, the lamp power changes by ±20%. For this reason, when using lamps of this type, it is necessary to use stabilizing devices that maintain the voltage at the same level as the battery discharges.
The light output of a xenon lamp ranges from 80 to 100 Lm/W. Xenon discharge has the highest brightness. According to theoretical estimates, it maximum brightness can reach 2000 MKd/m².
The bright, powerful luminous flux of the daytime spectrum allows you to evenly illuminate a large area, which makes such flashlights an indispensable tool for search work in accident sites, in conditions of heavy dust and gas contamination in mines, deep wells and caves. The light of a xenon flashlight is noticeable even during the day at a great distance, which is very important during rescue operations in the mountains and taiga.
This type of light source confidently replaces incandescent lamps and gas discharge lamps from modern models lanterns This fact is easily explained by the following advantages of LEDs:
- the LED, unlike a xenon lamp, is inertia-free and when a supply voltage is applied to it, it instantly reaches the nominal glow mode, just like a halogen lamp;
- the heating temperature of the LED is much lower than the heating temperature of halogen and xenon lamps;
- since when the LED lights up, less energy is spent on heating, LEDs, today, have the most high efficiency- up to 45%. By comparison, a halogen lamp has an efficiency of about 5%, a xenon lamp - up to 30%;
- The maximum luminous efficiency of LEDs used in industrial production is 120 Lm/W. The average luminous efficiency of LEDs used in battery-powered flashlights is 80 - 95 Lm/W, that is, comparable to the luminous efficiency of xenon lamps.
Light distribution
Powerful flashlights can be classified both by the type of light source and by the direction of the light flux. Speaking about the direction of the light flux, we can distinguish two types of powerful flashlights:
- spotlights. The beam of light from such lanterns has a wide front and is capable of illuminating objects located at a fairly large distance, more than five hundred meters;
- long-range flashlights. The beam of light from such lanterns has a very narrow directionality so that one bright spot is projected on the illuminated object, but the range of such a beam reaches one and a half kilometers. For information: the range of the flashlight is determined by the distance at which the illumination level is equivalent to the light intensity of the full moon, which is taken equal to 0.25 lux and is optimal for safe movement.
Spotlights are most effective at short and medium distances up to five hundred meters. Their the most important characteristic It is not the range of action, but the brightness of the light flux over the maximum area without deep shadow. This is ensured thanks to the special design of the reflectors. Spotlights are ideal for active rest, hunting and fishing.
Long-range flashlights have a completely different purpose. Long-range flashlights are used by speleologists, searchers, and miners.
Long-range flashlights usually include flashlights with a lighting range of 500 meters or more. This is also ensured by the design of reflectors and optics, which allow the light beam to be focused. What is important here is not the scattering of light, but its concentration at one point, the formation of a bright light spot.
Very often, the functions of spotlights and long-range flashlights are combined in one flashlight. Structurally, such lanterns have a movable (in the axial direction) diffuser and a lens mounted at the outlet. By adjusting them, they achieve the creation of a light spot of the required diameter. When adjusted, the angle of light redistribution and the focal distance between the lamp (LED) and the illuminated object change.
Rechargeable batteries
Powerful search LED flashlights mainly use two types of replaceable batteries for power supply, these are 26650 and 18650, with an output voltage of 3.7 V. Such rechargeable batteries are produced by many companies, have different prices, declared capacity values, discharge and charge times. Batteries of these types are widely used not only for powering flashlights, but also, for example, for making laptop batteries. Therefore, there should not be any difficulties in purchasing such batteries.
IN different models lights are installed different quantities batteries. Basically these are 2, 3 elements. There are a large number of flashlight models that have a universal container designed to install 1, 2 or 3 elements by adding a special insert supplied with the flashlight to the handle.
Since 18650 and 26650 batteries have the same length, 65 mm, some flashlight models can use batteries of both types. To prevent the 18650 elements from “dangling” inside the container, a plastic adapter sleeve is included with the flashlight.
In small lanterns it is possible to install 1 element. It happens that instead of 1 18650 element, 2 CR123A elements are used.
More powerful battery-powered LED flashlights can be equipped with D-type cells with a capacity of 10,000 mAh and a voltage of 1.2 V.
In general, when choosing a flashlight, you should definitely be interested in what batteries are used in them, and what they can be replaced with. To assess the possibility of such a replacement, see the tables of standard sizes of galvanic cells.
If you decide on a search light model, remember that for it to be successful, reliable and long work needed quality batteries. I think that if you are going to spend a significant amount of money on a flashlight Money, you should not skimp on its most important element.
In the case of flashlights that work with a xenon lamp, from the point of view of choosing a power element, everything is much simpler. All flashlights have their own batteries, which are supplied with the flashlight. Therefore, when choosing a flashlight, you don’t need to think about anything. However, if you look at this from an operational point of view, then over time there may be problems with replacing them.
Although there are exceptions. For example, the flashlight shown in the photo below is powered by four 18650 batteries.
Operating modes
Operating modes of flashlights with a xenon lamp, due to the inertia of turning on the lamp and limited number cycles of its on-off cycles, as a rule, have three operating modes, namely these are the modes in which the lamp operates at different capacities. Each lantern has an operating mode at minimum power, at which the lamp glows stably, an operating mode at rated power, and a forced mode, at which maximum brightness is created. When operating in the latter mode, the battery capacity is naturally consumed very quickly.
A powerful LED rechargeable flashlight, in addition to the listed operating modes of xenon flashlights, has two additional modes work is:
- stroboscopic mode. This mode is intended for self-defense from an attacking enemy, by disorienting him in space with very bright and frequent light pulses;
- SOS mode or beacon to attract the attention of strangers to you.
To summarize, we can conclude that powerful flashlights with halogen incandescent lamps have faded into the background. The leadership is shared by flashlights with xenon lamps and flashlights with LEDs. However, LED high-power flashlights have characteristics comparable to flashlights equipped with xenon lamps, and therefore are increasingly used.
And finally, we invite you to watch a video review of two portable, powerful rechargeable LED flashlights made in China and Germany.
