Microcircuit for switching flashlight modes. Benefits of a tactical strobe flashlight: myth or reality? Description of driver functions

The Chinese people's electrical industry is good for everyone, but it still does not reach the level of global manufacturers. A striking example of this is flashlights. High-quality, reliable, modern, but with jokes.

Specifically, this is the Phase lantern, that’s what it’s called. It shines brightly, the blue spectrum is almost invisible in the light, it is not expensive (with a battery it cost me 394 rubles). Three glow modes: bright, dim and strobe. And they all turn on sequentially every time the flashlight is turned on. That is, not like on the same Petzl - first the brightest, and then when you press again the following modes, but simply in a chain. Turn it on - bright, turn it off, turn it on again - dim, turn it off, turn it on - strobe.

I don’t need such a variety of modes; one bright one is enough. I had to eliminate unnecessary modes.

We unscrew the head of the flashlight and remove the converter unit.

Use an awl to pry up the contact pad and pull out the converter board.

We find the only microcircuit for selecting modes, heat up the two legs closest to the throttle and drop solder there so that it connects them together with a drop.

Let's put the module back together. To make the wires fit easily, we turn the converter board relative to the body a couple of turns. Then we make two diametrically located cuts on the top of the body. This will allow you to securely tighten the module when assembling the flashlight (for example, with the sharp jaws of powerful tweezers or side cutters). After this, the head will definitely not come off.

I received an order from a good friend who is interested in fishing. He had a simple Head Torch, which had a number of shortcomings, but was completely satisfactory in size and appearance. Well, for good man- a good thing, but for me it’s just training for the brain and hands.

Let's get started. To begin with, I will highlight the advantages of this flashlight:

• compact and lightweight body;
• ability to adjust focus;
• convenient location controls (button), considering that the flashlight is a headlamp.

Now there are many more disadvantages:

• inconvenient control - three modes that switch according to a cyclic algorithm (the fourth mode is “off”), that is, if you missed the desired mode, then you have to “click” all the modes in a circle until you “click” to desired mode;
• one of the modes - flashing - is generally useless, it only interferes with control;
• there is no monitoring of the battery condition, that is, with each discharge cycle it damages the battery, greatly discharging it (if you do not turn it off, it can drain the battery by up to 1...2 volts);
• there is no current stabilization, that is, as the battery discharges, the brightness gradually decreases;
• the battery is charged stupidly through a resistor, there is no control of the charging current and there is no correct algorithm charge lithium ion battery(every charge cycle destroys the battery);
• There is a Chinese LED with low efficiency;
• There is a Chinese battery with an inflated capacity on the label.

Now about what I would like to get in the end:

• convenient control of modes, remove the flashing mode;
• introduce current stabilization through the LED (install a driver);
• replace the LED with a more efficient and reliable one (CREE XPG), warm glow (instead of the standard cold one);
• monitor the battery discharge; when the battery is discharged, turn off the flashlight;
• add a lithium-ion battery charge controller;
• replace the battery with a normal one.

Open the flashlight housing.

Here we see that its “brains” are made on the basis of an LSI chip, so they cannot be modified in any way.

When replacing the LED with another LED, the output current changed by almost 50%, which indicates the absence of any current stabilization. It was decided to throw out the original board and make our own. I chose the ATtiny13A-SSU as the management controller due to the following main advantages:

• low price - about 30 rubles (at the time of writing, May 2014);
• compact body surface mount;
• in sleep mode consumes less than 500 nanoamps (!!!);
• possibility of working with low voltage power supply (up to 1.8V);
• ability to work at temperatures below 0 degrees.

The choice fell on the AMC7135 as the LED driver due to the following characteristics:

• ability to operate at low supply voltages;
• the minimum voltage drop on the microcircuit is only 0.15V;
• possibility of PWM adjustment of LED brightness;
• compact body.

Driver circuit:

A short explanation about the operation of the circuit and the components used. To measure the battery charge level, the ADC of the microcontroller and an external reference voltage source (hereinafter referred to as ION) REF3125 with an output voltage of 2.5V are used. An external ION is used for a reason - it helps to measure battery voltage with minimal errors, since the accuracy of the ION built into the microcontroller leaves much to be desired. The AMC7135 is controlled using a PWM signal with a frequency of 500 Hz. When the driver is turned off, the microcontroller turns off AMC7135 de-energizes the ION and goes into “Power Down” sleep mode, consuming less than 1 µA. The device does not require any configuration or adjustment, and after assembly and firmware it starts working immediately so that you can select the driver shutdown voltage “for yourself.” , at the end of the article is attached an archive with firmware for voltages of 3.1...3.6 Volts in increments of 0.1V.

I spread the signet, etching, soldering, writing software in AVR Studio 5, flashing the microcontroller. At the board manufacturing stage, you need to drill holes and connect the tracks on both sides of the board with jumpers. I took a copper core from a twisted pair cable, tinned it, and made jumpers from it.

That's what came out of it. The signet and firmware set can be downloaded at the end of the article.

On one side of the board (double-sided with a diameter of 18 mm) all the control brains were located, on the other side of the board there was an LED driver with a copper polygon for proper cooling. Optionally, a second AMC7135 driver chip can be installed on the board to increase the maximum output current from 350 mA to 700 mA. The small size of the board was not chosen by chance - it was necessary to fit the driver in its original place in the case. Here is a photo to estimate the size of the resulting scarf:

The native control controller supplied the following current to the LED in the following modes:

• 1 mode, approximately 200 mA;
• Mode 2, approximately 60 mA;
• Mode 3, approximately 60 mA (flashing).

The native controller is controlled according to the following algorithm. When the button was pressed, the transition to the next mode was performed. 1 --> 2 --> 3 --> OFF and so on in a cycle. If you accidentally missed the desired mode, you will have to sit and “click” until you reach the desired mode. Also, to turn off the flashlight you need to click through all the modes. You can’t even dream about quickly turning on/off the flashlight.

My controller board with driver produces the following currents in different modes:

• 1 mode, 30 mA;
• 2 mode, 130 mA;
• Mode 3, 350 mA (will be used for a short time, since the flashlight body does not provide proper cooling for the LED).

My controller is controlled using the following algorithm. A single (short) press turns the flashlight on/off (while maintaining the last selected mode). Holding the button for a long time switches the mode to the next one. Thus, we have the ability to quickly turn on/off the flashlight and change modes. The annoying and useless “flashing lights” mode is now gone. When the battery voltage drops to the level specified in the firmware, the flashlight switches to the previous mode. That is, if mode 3 was set, then first the controller will turn on mode 2, then the flashlight will work for a while, then mode 1 will turn on, the flashlight will work for some more time, and only then it will turn off. There are already similar designs on the Internet, but they either have control by breaking the power circuit, which is not always justified, or they do not use sleep mode, and this is very important!!

So, we throw out the old brains, and also remove the capacitor, for some reason connected in parallel to the button. Probably the Chinese were struggling with contact bounce. My bounce processing will be software, so the capacitor is no longer needed.

We’ll also take out the standard LED and replace it with an efficient one. CREE LED XPG with a warm glow.

Preparing our new LED:

Assembling the optical unit:

Now we embed new board control controller and LED driver:

Assembling the body:

Thus, on appearance no changes have occurred, but inside now everything is as it should be. Battery discharge monitoring, current stabilization, normal mode control, and the “correct” LED. When turned off, the controller consumes little power as the microcontroller goes into sleep mode.

Later, a normal battery charge controller was installed on the MAX1508 chip, and the native Chinese battery was replaced with external unit batteries, consisting of 2 original cans Sanyo UR18650.

In active mode, the ATtiny13A microcontroller consumes less than 500 µA due to its clock speed of 128 kHz. Also in active mode, the consumption of the AMC7135, the consumption of the external ION, and the consumption of the internal ADC of the microcontroller are added. The total current consumption in active mode depends on the ion used, and can range from 0.1 mA to 1 mA. I used the REF3125 ION, the total consumption of the circuit in operating mode was 0.5...0.8 mA.

ION REF3125 can be replaced with analogues:

• ADR381
• CAT8900B250TBGT3
• ISL21010CFH325Z-TK
• ISL21070CIH325Z-TK
• ISL21080CIH325Z-TK
• ISL60002BIH325Z
• MAX6002
• MAX6025
• MAX6035BAUR25
• MAX6066
• MAX6102
• MAX6125
• MCP1525-I/TT
• REF2925
• REF3025
• REF3125
• REF3325AIDB
• TS6001

Attached short video, demonstrating mode control. The video was shot a long time ago, the LED was original back then, later it was replaced with CREE XPG, and the original battery was also present. I was too lazy to shoot the video again. I also want to warn you that not every programmer supports microcontroller firmware at 128 kHz. For the firmware I used the "USBAsp" programmer with the "Slow SCK" option enabled. Happy crafting everyone!!

Attention! The firmware of the control microcontroller has been completely rewritten. The program's operating algorithm has become more correct, and some shortcomings in the device's operation have been eliminated. Below you can download a trial version of the firmware with a operating time limit of 10 minutes. After the test time has expired, the LED goes out and the control is blocked. After reconnecting the battery, we again get 10 minutes of test time.

The full version of the firmware can be purchased.

List of radioelements

Designation	Type	Denomination	Quantity	Note	Shop	My notepad
	MK AVR 8-bit	ATtiny13A	1	SOIC package 208 mil		To notepad
	Capacitor	1 µF	1	not less than 1 µF		To notepad
	Resistor	4.7 kOhm	2	or 3...10 kOhm

Many of our clients to whom we brought a “tactical flashlight” to order - no, no, no, and they ask about the usefulness of such a thing as the strobe function (quickly reproducing repeating bright light pulses). Unfortunately, in Russian practice The stroboscopic glare effect is practically not illuminated, which has led to many myths and misconceptions. In this article we will try to fix this. We should start with the background: how the strobe effect appeared and what it actually is.

What is a strobe?
A stroboscope (from the Greek “strobos” (circling, random movement) and “skopio” (looking)) is a light source (lamp, flashlight, spotlight) that flashes at different frequencies. A person who sees these flashes has a feeling of electric welding flashes, a starry sky or a lightning bolt. Accordingly, a tactical flashlight with a strobe means a bright flashlight that can quickly blink (flicker) and blind the enemy. However, how to evaluate the effectiveness of this blinding (and, accordingly, evaluate the benefits of the strobe)? First you need to delve into the theory.

Booch effect
Back in the distant 1950s, the disorientation ability of light flashes was “discovered.” When exposed to low-frequency flashing or flickering light, the person began to experience slight clouding of consciousness. They did not pay much attention to this phenomenon if it were not for the increasing number of complaints from helicopter crews complaining of disorientation and dizziness. Looking at the sky, the crew members were exposed to the blinding effects of the sun: the rotating blades of the helicopter caused the light to “flicker”, creating a strobe effect and preventing the pilots from controlling the machine, as a result of which emergency situations occurred quite often.

Due to the uproar in the press, scientific research. Dr. Butch was the first in the world to scientifically describe this effect. Unfortunately, his name was lost, but the laurels of the discoverer remained. Subsequently, the psychological effect of the strobe light was called “ imbalance of brain cellular activity caused by exposure to low-frequency flicker bright light ". To achieve the desired effect, the “flicker” had to be produced with a frequency of 1 to 20 hertz, i.e. Roughly matches the frequency of human brain waves. By the way, epileptic seizures occur for approximately the same reasons. This effect is also called “Flicker vertigo” ( Wikipedia.org/wiki/Flicker_vertigo ). Nowadays, if you pay attention, you will notice that almost all helicopter pilots (including in cinematography) wear polarized sunglasses - one of the reasons for this is the same “Butch effect”.

Principles for the widespread development of the strobe
The history of tactical flashlights is far from new - they existed before, they exist now. However, previously the possibility of a flashlight with a strobe function could not be realized purely physically due to the technology being unsuitable for this.

Now that lamp lamps are practically a thing of the past and almost 95% of products are sold on LEDs, all roads are open to strobe. This can be solved in a couple of seconds by programming the microcontroller. In addition to the strobe function (fast flashing), LEDs allow you to implement simpler functions: for example, sending an SOS signal or beacon mode.

However, manufacturers often push the strobe to the heap (if only there was one), cunningly using marketing for their own purposes. Like, don’t hesitate, dear buyer, you will need it. How to determine whether there is a strobe in a flashlight cunning trick sellers, or is this a truly important tactical innovation?

You need to weigh the pros and cons.

The strobe light disrupts the enemy's vision, i.e. directly affects his ability to use brute physical force and also disrupts his mental state, causing the effect of confusion, i.e. directly affects his ability to take ANY action (including shooting at you to kill, if we are NOT talking about physical resistance).

The stroboscopic effect is based on the brain’s perception of the so-called “afterimage”. Almost all of us have encountered something similar. for a long time looking at the sun or a bright light bulb. A so-called “visual imprint” is created in the human brain (and not on the retina, as many people think), caused by short-term exposure to point light at a high level of intensity. This print is an intangible image (i.e., not ingrained into the retina), which can change (size, shape, etc.) depending on the duration and frequency of light exposure. The effect of disorientation and dizziness occurs if such imprints-images appear and disappear at too high a speed, i.e. change so often that the brain does not have time to adapt to their cycle and frequency.
Strobe tactical lights do not allow the photoreceptors to reset, i.e. cause the same disruption in a person’s field of vision. The bright, flickering light tricks human perception by imitating information coming in segments, while the brain tries to piece them together into a coherent image that changes with each flash. “Afterimages” accumulate with each flicker, which overloads the enemy’s brain and causes disorientation almost instantly.
A homemade prototype of such a “weapon” has been a tool of psychological pressure during interrogation for many years: few have not seen how a criminal is shined with a lamp in the eyes.

In the movies, we have repeatedly seen how good police investigators place a source of bright light directly opposite the suspect’s eyes. If you strain your memory, many will remember the scenes where the lamp during interrogation swayed. Then, in the absence of LED lights, the strobe effect was created in this way, taking the interrogated person out of mental balance. If the lamp did not sway, then it was moved (for example, moved along the table) manually, supplemented by shouts of “Are you going to answer?!” Speak! Come on!". This was done so that the auditory impact (screams) would have a greater psychological effect due to the fact that visual perception of the world (vision) is inaccessible due to the blinding effect.

This, by the way, is one of the main reasons why you should not sit facing the fire (especially looking at the fire). Only careless tourists or complete beginners in the “survivalist” craft sit like this - professionals know that fire “attracts the eye.” Scientifically, this “attraction” is explained by the fact that the human eye reacts more actively to movement than to immobility. Many teachers use this when during a lesson they do not sit motionless at their desk, but walk around the room, forcing students to watch themselves and concentrate. This is also explained by the fact that fire varies in intensity of light exposure and light gradient (some pieces are lighter, others are darker, the color and intensity of light is constantly changing (tongues and flashes of flame, flickering coals, etc.)). This means that certain parts of the eye are illuminated and a loss of combat effectiveness (the illuminated part of the eye will temporarily not see movement).

This effect once again proves the effectiveness of the strobe.

Summarizing the pros and cons of a strobe:

A flashlight with a strobe function has several of the most reliable and time-tested advantages, namely:
1) Disorients the enemy
2) Violates the direct and peripheral vision of the enemy
3) Increases the time the enemy adapts to the situation
4) Causes short-term fear, confusion, numbness
5) Increases the recovery time of the enemy’s night vision
6) Creates a visual and psychological barrier against aggression

However, in addition to the advantages, there are some disadvantages and tactical problems that can greatly hinder in a real combat encounter.

When exposed to light WITHOUT the accompaniment of a source of constant (non-flickering) light (for example, a headlamp or a partner with a regular flashlight or a cover officer with a spotlight), the strobe “smears” the vision of its owner, which leads to the fact that a person without experience in using a strobe LOSES the ability to notice slow or smooth movements. You could encounter a similar effect at almost any disco, if you tried to move your hand in the flickering rays of light.

In the USA, a series of tests were conducted among police officers, simulating a real detention. The officer stood opposite the criminal and turned on a strobe flashlight, demoralizing the enemy. The test results showed that the instructor, playing the role of a bandit, could absolutely calmly move his hands to a distance of 20-30 cm long, before the policeman noticed his threatening intentions. It is worth noting that if you are playing the role of a “bandit,” then your movements should be made as smooth, slow and careful as possible in order to avoid premature detection.
In addition, the impact of any bright light on the retina in low light conditions (in the dark in particular) instantly and completely impairs night vision. Research on the topic “Which hits the eyes harder in the dark – strobe or direct light” practically none, but de facto the strobe will have a STRONGER effect, because In addition to illuminating night vision, it introduces the effect of disorientation in space. This is due to the fact that the period of adaptation of human vision after a short flash is much shorter than after a series of flickers.
To put it into words, many of us, being in the dark, have repeatedly received a “light shock” to our eyes - for example, from the backlight from a phone (we looked at the time at night), the TV turned on (on a bright stage, especially with full white illumination of the screen) or, for example, a monitor computer (we lay down to rest, listened to a couple of songs, the monitor went out (screen timeout). We got up, “awakened” the monitor - it hurt our eyes).

You can take even more life-threatening options - a random reflection from an ordinary mirror in the dark, causing discomfort and instant disorientation. All these cases are a single flash, after which vision is able to QUICKLY (literally in 1-2 seconds) recover and adapt to changed conditions, i.e. night vision “turns on” again. After a series of similar flashes, the eyes begin to get tired and “lose” the picture.
This can be seen on dark alley, illuminated by lanterns standing quite far from each other (that is, when there are “pieces” of darkness between the illuminated areas.

A man walking through such terrain in dark time days, is constantly exposed to disorientation, because the eye does not have time to focus and the surrounding dark space is “blurred”. Similar moments have been repeatedly shown in films - when a victim, walking along a street illuminated in a similar way, does not notice the maniac following her.
Those who repeatedly drive on an unlit highway at night will understand perfectly well this part articles, because in fact, they are constantly exposed to the “strobe effect” from oncoming cars. Each of them moves with at different speeds and has its own type of headlight with different angles tilt to the ground and different lighting intensities, as well as different types light element (incandescent lamp, xenon, etc.). The car driver receives flashes of different frequency, brightness and intensity in his eyes, which constantly keeps him half-blind and unable to quickly respond to an emergency change in the road situation. If it still begins to snow or rain, where each of the drops is, in fact, a lens focusing light...

This “blinding” is associated with the so-called “dark adaptation of the eyes” factor. In short, it is as follows:
0) dark adaptation begins from the moment the eyes are immersed in darkness and is divided into three stages
1) during the first (15-30 minutes depending on age and state of vision), the most intense adaptation to low light conditions (or complete absence of light) occurs
2) during the second (30-60 min) there is a gradual and continuous increase in light sensitivity
3) during the third (60-80 minutes) final and complete adaptation to darkness and full “switching on” of night vision occurs.
This is due to the fact that the human eye consists of several layers of nerve cells ending in the terminal apparatus: cones and rods, which are light receptors. These receptors in various ways react to different light intensities. Cones have lower sensitivity and are a device daylight allowing you to distinguish colors. Rods, on the contrary, are highly sensitive to weak light intensities and are night vision devices (there are many more of them in the retina).
In other words, adaptation occurs only after the layers of these receptors adapt and “settle” in your eye.
With the strobe effect, they cannot “settle down”, because forced to constantly react to the next change in the color and illumination of the “visible” space. This manifests itself even in small things - almost every person has at least once left a brightly lit room onto a dark porch, where he immediately “got lost” and became almost blind. Or vice versa - from a dark, unlit entrance, go out into the light. Most interesting fact that after such a change of locations a person is NOT ABLE to conduct effective observation until approximately the middle of the second stage, i.e. For almost 45 minutes the person does not look like a worthy sentry.
According to the dynamics of dark adaptation of the eyes, after 5 minutes the sensitivity of the eye increases by only 30% of the initial level, and after 15-20 minutes - by 80%. This time depends on the “difference” between the old and new, established sensitivity. It is one thing when a person plunges into darkness from twilight, another thing when he was previously in a brightly lit room. At the same time, when a person constantly alternates between illuminated and unlit locations, the sensitivity of the eye drops even below 30%. “Blindness” is maximum when a person plunges into darkness immediately after crossing the illuminated area. In the case of a strobe negative factor is that the person using the strobe is exposed to its influence, albeit to a much lesser extent, constantly falling from the illuminated “area” into darkness.

Briefly summarizing the disadvantages and disadvantages of the strobe light:

1) The strobe makes it difficult to notice slow or smooth movements
2) The strobe light blinds its owner, even if directed in the opposite direction
3) Combat use A strobe light is contraindicated for beginners who are not accustomed to its effects.
4) All of the above points can be solved by the presence of an independent additional source of CONSTANT light, i.e. a second non-flickering flashlight (eg a headlamp) or a partner with a flashlight.
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The need to use a strobe light

During a full-fledged combat encounter, lack of awareness and lack of data about the enemy is in itself a strong psychological factor that causes stress, as well as... fear. This is what the “tactical” strobe light is based on - visual and psychological pressure on the enemy. At its core, disorientation in front of a strobe is a fear of the unknown, of an incomprehensible “frightening” influence. One of the tasks of a police flasher is precisely this effect (a rotating or flashing flashing light creates the same stroboscopic effect).

While under the influence of flashes, most people are limited in their ability to receive visual information about what is happening around them, i.e. his attention is unable to concentrate on anything, which leads to instant discomfort, and then the gradual emergence of fear. Terrorists are not able to identify the size and threats (police, special forces), the number of attackers, their physical presence, exact location, conditions environment and many others. All this serves as a fairly strong deterrent and can be very, very effective in the right hands. You can more or less evaluate the effectiveness of this from this video:

Even despite the indirect impact (through the camera), it becomes noticeable - with a strobe light, movements are much more efficient (less noticeable to the enemy).
During tests of US police officers, it was found that movement with the use of a strobe light is much more effective than without it. Using a tactical strobe, the officer could move up to 25 feet (~8 meters) BEFORE the "bandit" noticed that he was moving. Almost all of the officer's movements over shorter distances went unnoticed and were incorrectly or inaccurately identified. In the same tests, with a STATIC effect (i.e., the officer stood still), the strobe lost its effectiveness much faster. However, the light sensitivity of peripheral vision plays an important role here. If the strobe light is static (located in one place), and its owner is displaced a little further (for example, standing a few steps to the side), then there is a high chance that the enemy will either not notice the owner, or will not be able to adequately assess the degree of threat and will try first. knock out the strobe itself. In other words, if you put down a flickering flashlight, and step back and take a firing position a little to the side, you will be safer than hiding behind a strobe light. These tactics are ideal for defending objectives or holding corridors and other choke points.

To summarize briefly:

1) A tactical strobe is more useful than vice versa
2) The strobe is most effective when its carrier is constantly moving
3) Dynamic strobe (moving) is effective in attack
4) Static strobe light (fixed) is effective for defensive tactics and holding positions

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Strobe frequency
The flickering frequency of the strobe plays a significant role:
— Frequency up to 2 hertz (1-2 flashes per second) is used in fire alarms, schools, hospitals, stadiums, etc. and is completely safe.
— Frequency up to 8 hertz (6-8 flashes per second) has a slight effect on humans (visual difficulties and the appearance of multi-colored lights are possible).
— Frequency up to 12 hertz (10-12 flashes per second) has a full stroboscopic blinding effect
— Frequency up to 16 hertz (14-16 flashes per second) has a full stroboscopic blinding effect
— Frequency up to 25 hertz (23-25 ​​flashes per second) is ineffective and has virtually no blinding effect
Most modern "tactical" strobe lights have a factory limit on the flicker frequency of 10-12 hertz (10-12 flashes per second). As a rule, this is quite enough to cause blindness.

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Strobe lights, epileptic seizures and the Police Law
Although rare, the stroboscopic effect can cause convulsions and an attack of photosensitive epilepsy in the blinded person. One example of this is the case that occurred in 1997 in Japan. During the screening of one of the episodes of the animated series " Pokemon" was depicted big Bang, which featured an alternation of flashing blue and red lights, resulting in 685 children who saw the scene being sent to the hospital. The reason for this was that the explosion shown was a stroboscopic flash involving several colors at a frequency of approximately 20 hertz. Despite the fact that 90% of the 685 hospitalized children complained only of dizziness, some of them had to be admitted for treatment due to individual characteristics.
A similar practice is also found in the archives of special services - mainly Western ones, since this is little documented in the Russian Ministry of Internal Affairs. Some of the criminals whom police officers came to apprehend with a strobe light fell into a stupor and experienced a minor attack of convulsions, which made it possible to subdue them without much effort. In most cases, these were people under the influence of surfactants (narcotics) or the influence of strong alcohol. Unlike a stun gun and other similar tools for influencing criminals, a strobe flashlight is not a special tool, it is allowed for free sale and is completely legal. In the event of a seizure in a caught criminal, the police officer who used the strobe light does not fall under the scope of the Police Act because the harm he caused was not intentional, and also does not in itself fall under the category of “harm” or “violence” (an ordinary flashlight).

________________________________________

Conclusion:
In conclusion, we can say that a flashlight with a strobe function is a useful and necessary thing and can come in handy in difficult times. The advantages of the stroboscopic blinding effect outweigh the disadvantages - all that is required is to practice and get used to the strobe before “combat use”.
You can order a tactical flashlight with a strobe function in our store.

Many people buy goods from China. This has its advantages (cheapness) and disadvantages - you cannot touch the product before buying. So I ordered a flashlight on Aliexpress. After receiving it and completely disassembling it, one of the shortcomings immediately emerged - the cooling of the LED. There was a void under the substrate and the “star” was in contact with the body only at the edges. Therefore, after prolonged operation, the case remained warm, and the LED was boiling. Since I don’t have a familiar turner, I had to use an adapter heatsink between the housing and the LED substrate.

Firstly, the contact with the body has improved, and secondly, additional cooling has appeared in the form of a cylindrical radiator. All joints were coated with thermal paste, and the structure was assembled together. I’ll immediately make a reservation about cooling. There are different versions of this flashlight. And the second version does not have a hole under the substrate, but only two holes for the wires.

If you come across such a design, then you are lucky; if not, then you definitely need to take care of cooling. The LED gets very hot. Measuring the temperature for several minutes near the LED showed more than 100 degrees. This is unacceptable for the long life of your ray of light.

Now about the second improvement: the driver. When I ordered the flashlight, I immediately decided that I would exchange it for a more convenient one. Many people are annoyed by these strobe lights and SOSs, and even by the inadequate turning on of the flashlight after previous work. When turned on, it jumps to the next mode, and if in last time you worked with the minimum mode, now it will turn on the strobe light for you. I'm definitely not happy with this. Let's move on to the driver itself. The driver below is a friend's design AVSel, for which I express my deep gratitude to him. Unlike special microcircuits, it is made . All files for it.

Driver circuit for MK

Description of driver functions

1. The flashlight has 5 operating modes. The most minimal mode is done by PWM for reasons of maximizing efficiency from the battery. I got the following currents - 0.03 A - 0.07 A - 0.20 A - 0.55 A - 1.40 A. They can be changed by selecting a low-resistance resistor, and the drop across it will be 50 mV. Using Ohm's law, you can calculate how much resistance is needed for the selected current.
2. Battery discharge monitoring. When the voltage drops below 3.0 V, the driver switches to minimum mode and blinks smoothly once every 10 seconds. If the blinking is disturbing, you need to turn off the flashlight for a couple of seconds and turn it on again. When the voltage drops below 2.75 V, the flashlight turns off and goes into sleep mode with a current consumption of about 0.3 mA.
3. When switching to the minimum mode, the battery charge is indicated from 5 blinks (fully charged) to 1 blink (discharged). After the indication, the minimum mode is activated.
4. Smooth start. The start time depends on the selected mode. 0 seconds for minimum and approximately 0.8 seconds for maximum.
5. Possibility to enable thermal control.

To enable thermal control, you need to calibrate:

• set the minimum mode and turn off the power,
• set the supply voltage to 4.5..5 V and supply power,
• the driver detects this condition, resets the previous calibration data and switches to maximum mode.
• We warm, we warm, we warm, measuring the temperature with a thermometer or finger. When we think it’s enough, we lower the voltage to 4.2 V or lower.
• the driver turns off the LED, pauses for 2 seconds to stabilize the supply voltage and temperature, and stores the calibration temperature value in the EEPROM. If you turn off the power before this point, the thermal control will be disabled.
• after saving, the driver turns on the minimum mode, calibration is completed,
• turn off the power, cool it a little, turn it on, turn it to maximum mode, heat it up, check the operation of the thermal control.

I set this mode to about 80 degrees on the LED substrate. At maximum current, the flashlight works for about half an hour, after which it turns off. It is quite possible that the temperature increase is also helped by the transistor, which heats the controller on the other side of the board.

At the same time, the case is noticeably hot, and the temperature on the LED itself does not exceed the set one. This tells us that the cooling is quite efficient compared to the initial version. And in winter they are great for warming your hands.

Also on printed circuit board There is protection against polarity reversal on the P-channel transistor. First, it was tested without soldering the microcontroller, and then on a working flashlight by turning the battery over. Now a flashlight can be considered an excellent assistant in dark places, and not worry about the condition of the battery and LED. Especially for - SssaHeKkk.

Discuss the article IMPROVING THE OPERATION OF A FLASHLIGHT

Anton INS 18-12-2010 22:51

The question is actually in the subject.
Tonight I thought - why?
What is it used for initially and who uses it for what?

awl 18-12-2010 23:12

Initially, the creators did not know what to do with the flashlight microcontroller, and added this function supposedly to disorient the “enemy”. For its time it was probably cool, especially after lamp lanterns, where this was impossible to implement.

ilkose 18-12-2010 23:34

It really stops dogs, but not all)))

John Jack 18-12-2010 23:50

Because setting the brightness mode for most diode lamps was done through PWM, which is the quick switching on and off of the light. It was logical to make a strobe, SOS and other blinkers, because for this there was no need to change anything at all in the flashlight, just add a few lines to the firmware.
And now this is a bad tradition, for some reason manufacturers believe that a flashlight without a built-in disco will sell worse, especially the DX Chinese, who can sacrifice one of the necessary modes for the sake of strobe or SOS. Although now more special flashlights are made without frills, and many less special flashlights have strobes hidden deeper in the interface.

Der Alte Hase 19-12-2010 01:35

The strobe can be both signaling and disorienting. If I still understand the presence of the first in flashlights with reverse-click buttons, then the second is an absolutely stupid feature. Disorienting, incl. owner of the lantern...

psm 19-12-2010 02:15

When we ride bikes in places where there are pedestrians, I turn on the strobe.
My son has mirrors on his bike - after 15-30 minutes he complains that my strobe makes him sick.
Pedestrians react better to a strobe than to just a flashlight - more noticeable.

Donkey11 19-12-2010 04:17

I would throw you off my bike for the strobe you shine in my eye, and someone will arrange it for you.

alex.g 19-12-2010 07:48

I would throw you off my bike for the strobe you shine in my eye,

Keyboard Rambo? I recommend going out on the road and leaving your cars. I especially recommend it with flashing lights if there is nowhere to apply aggression.

during the day

Anton INS 19-12-2010 09:49

Thanks everyone for the comprehensive information!

combat_rabbit 19-12-2010 11:47

And lately this is the only way I cross the road (not directly into the drivers’ eyes, but a little down) especially in illuminated areas, just with a burning light no one lets me through!

psm 19-12-2010 12:09

Of course, in pedestrian areas, a pedestrian has complete priority over a cyclist. But since there are no bicycle paths in our country, let’s somehow get along. Flashlight strobe during the day- this is a very adequate option to attract attention. Both drivers and pedestrians. And quite harmless. At night it is better to use just light - it is already noticeable. Or, in addition to the light of the flashlight, turn on a bicycle blinker - they do not dazzle.

P.S. And throwing a cyclist off his bike can lead to jail time. Hooliganism, causing bodily harm.

balash33 19-12-2010 14:06

quote: A strobe from a flashlight during the day is a very adequate option for attracting attention.

Recently I met some friends who had arrived from the south at the airport. There are hundreds of cars, they all have headlights, the frost is -30. They couldn’t find me until I identified myself with a strobe light. I think that let it be, you don’t have to turn it on if you’re allergic to the strobe :-)

Der Alte Hase 19-12-2010 16:56

Well, confirmation... Most people use a signal strobe. There are no problems with the direct click button, i.e. It is needed in flashlights with reverse click buttons. Bicycles don't count. To be honest, I vaguely imagine how you can drive with the strobe on... After a few seconds without driving, you begin to feel the effects of it...

Der Alte Hase 19-12-2010 17:02

....especially after lamp lanterns, where this is impossible to implement.

Why is it impossible? Implemented a long time ago. AW softstarter for maglights and shuriks, for example. I sometimes blink five thousand lumens in nature... For fun. You can organize sabotage on the highways...

awl 19-12-2010 17:16

With a frequency of 10-15 hertz?

Luddit 19-12-2010 18:57

Maybe sometimes a strobe is needed, but lights that cannot be turned on and off without going through that strobe are infuriating.

Anton INS 19-12-2010 19:06

After a few seconds without driving, you begin to feel uneasy about it...

I noticed that this effect depends on the frequency of the strobe: on some it’s normal, and on some it’s “so vomit and throw away.”

mr.ttrx 19-12-2010 19:47

The movie "Kick-Ass" shows what a strobe is needed for. I also tried it once on dogs, and they ran off into the darkness with a squeal.
Theoretically, it should blind well those wearing NV.

Anton INS 19-12-2010 19:59

quote: Originally posted by mr.ttrx:
I also tried it once on dogs, and they ran off into the darkness with a squeal.

ag111 19-12-2010 20:14

There are people whom the strobe can drive into a mental attack. So throwing it off the bike is still humane.

awl 19-12-2010 20:15

Sometimes I’m too lazy to get up to chase away the cats from somewhere, I try to blink the flashlights - but they absolutely don’t care, even a 1200lm strobe

grajdanskiy 19-12-2010 20:16

quote: Originally posted by Anton INS:

Dogs don't have very good night vision, but on cats it should have a mega effect

Oddly enough, but it turns out the other way around...

Anton INS 19-12-2010 20:37

quote: Originally posted by ag111:
There are people whom the strobe can drive into a mental attack. So throwing it off the bike is still humane.

Yes, by the way, blinking can provoke an epileptic seizure.

Anton INS 19-12-2010 20:38

quote: Originally posted by awl:
Sometimes I’m too lazy to get up to chase away the cats from somewhere, I try to blink the flashlights - but they absolutely don’t care, even a 1200lm strobe

Oh, what kind of light-resistant ones did you get?

Danill 19-12-2010 22:52

I also tried a 650lm strobe on cats. There's no reaction. If you shine a light closer than a meter, then the animal’s dissatisfaction is noticeable. I even tried it on one marten - the same thing.
In general, strobe, sos, etc. Let them be better, but hidden. Although in my opinion the most useful mode, this is a flashing beacon - short flashes, with an interval of several seconds, and with long-term operation of the flashlight in this mode.

Joker12 20-12-2010 12:39

The strobe light has proven to be an excellent means of indicating/attracting attention. This looks especially clear in autumn weather. In light rain and twilight, car enthusiasts are especially familiar with such conditions - when the asphalt shines, the light from the headlights is mostly scattered in the wet asphalt. Not much illumination. Providing a signal with a strobe in such conditions is an absolute benefit. The human eye immediately reacts to the strobe.

Donkey11 20-12-2010 12:28

quote: Originally posted by alex.g:

Keyboard Rambo? I recommend going out on the road and leaving your cars. I especially recommend it with flashing lights if there is nowhere to apply aggression.

And what does this have to do with cars, you don’t like it when drivers behave like pigs on the road without switching to low beam or fucking xenon?
And here you have a focused light in your face, how long have you been shining it on yourself?
There are bells to indicate this, and according to the rules, a cyclist has nothing to do on the pedestrian sidewalk. Not only does he break these rules, but he also hits people in the eyes with a flashlight.

quote:
Of course, in pedestrian areas, a pedestrian has complete priority over a cyclist. But since there are no bicycle paths in our country, let’s somehow get along. Flashlight strobe during the day- this is a very adequate option to attract attention. Both drivers and pedestrians. And quite harmless. At night it is better to use just light - it is already noticeable. Or, in addition to the light of the flashlight, turn on a bicycle flasher - they do not dazzle.

P.S. And throwing a cyclist off his bike can lead to jail time. Hooliganism, causing bodily harm.

Oh, okay, tell stories, it just fell, you have to drive carefully))

Donkey11 20-12-2010 12:42

quote: Originally posted by psm:

It makes no sense to explain to some that a light on a bicycle is meant to shine on the road under the wheels and not into the eyes of oncoming people. Everyone measures for themselves.
The roads are full of goats with collective farm xenon and incorrectly adjusted neighbors :-)
And for excessive aggressiveness, I recommend a woman.

Those. Is it normal to shine a strobe in the eyes of passers-by, because they don’t understand something? Fools all around
Then don’t be judgmental when someone who has misunderstood pushes a flashlight up your ass. )
You need to treat others humanely and not think only about yourself. The strobe is somewhat blinding even from a distance. It attracts attention, but it's like knocking on a door with a hammer. Is it not fashionable to put a bell on a bicycle?

mt1000 20-12-2010 12:48

What did you have in physics or geometry at school?
If a cyclist shines on the road, he shines at an angle to the ground.
tell me what bolt he should use to adjust the flashlight so that it shines above the road
and even in people’s eyes?

Or is it just a seasonal exacerbation and you have no one to quarrel with?

Donkey11 20-12-2010 13:01

Apparently you had absolutely zero knowledge on this subject. Judging by the nonsense that you wrote. And apparently you only saw the bike in the picture. )))) Place the flashlight at an angle “to the ground” and walk around, theorist. You are not shining laser light and the angle of inclination is not 90 degrees.
It's good if it's 30 degrees.

Donkey11 20-12-2010 13:33

Come on, Hedgehogs are proud birds and will not fly until you kick them.

alex.g 20-12-2010 14:39

quote: Originally posted by Der Alte Hase:
To be honest, I vaguely imagine how you can drive with the strobe on... After a few seconds without driving, you begin to feel the effects of it...

It's really stupid to drive at night with a strobe. Just constant light is already noticeable in itself. The strobe is relevant during the day first of all. And it is especially relevant on the road. The difference is felt very well when you drive with or without a strobe. Drivers leaving secondary roads or courtyards often do not perceive a cyclist riding on the main road at all, although they are obliged to yield. A colleague of mine had a serious breakdown in this way, and I myself almost stopped at the door of such bullies several times. If you are driving with a strobe, then the first thing the driver reacts to is his peripheral vision, and often this is enough for him to reflexively press the brake even before he figures with his chicken brain that the bicycle is much lighter and softer than his car and therefore can be brazenly pushed.

In pedestrian areas in the evening there is really no point in turning on the strobe. But an ordinary bicycle front warning light is quite acceptable. They usually blink at a low frequency, shine widely and dimly, but indicate a cyclist quite well.

Donkey11 20-12-2010 15:38

I installed a good old bell on my bike, it identifies itself very well. But this is kind of not fashionable now. And I agree with the road, cyclist drivers are for the participants traffic in most cases they do not count, although this is more noticeable in a big city

alex.g 20-12-2010 16:05

quote: Originally posted by Donkey11:
I installed a good old bell on my bike, it identifies itself very well. But this is kind of not fashionable now.

Donkey11, the world is much wider than your circle of perception and your cycling places. Not a single pedestrian will hear the good old bell when you are driving along Leningradka (there is such a street in Moscow). And at the mention of the pneumatic horn, you will probably start talking again about your strange perverted fantasies about stuffing foreign objects in the anus of strangers

Donkey11 20-12-2010 16:30

quote: Originally posted by alex.g:

Donkey11, the world is much wider than your circle of perception and your cycling places. Not a single pedestrian will hear the good old bell when you are driving along Leningradka (there is such a street in Moscow). And at the mention of the pneumatic horn, you will probably start talking again about your strange perverted fantasies about stuffing foreign objects into the anus of strangers

And in general, what annoys you? How many times have cyclists shined a strobe light in your eye? And by the way, how many have you already lost?

Go because you have to go footpath and in the rightmost row of Leningrad itself, if you haven’t read the DD rules. Then there will be no problems with annoying pedestrians. They are not obligated to give way to you at all, not at the bell, not at your air horn. This is just for reference.
That's right, when you're running 20 km along a pedestrian road, whoever can run up. And strobe and suck and curse words will all be used.
Judging by the fact that you don’t like what I’m saying, you actively apply it yourself. I met such riders more than once or twice, and honestly my hands were itching. Because he smears himself with mud and rushes like crazy, ready to knock down everything in his path.
Thank God they haven’t shined a strobe in my eye yet, but I know very well how it shines, I have a flashlight on my bike myself.
What’s annoying is that cyclists scold others, the same drivers, but don’t notice their own mistakes in relation to the same pedestrians.

alex.g 20-12-2010 16:42

quote: Originally posted by Donkey11:

Thank God they haven’t shined a strobe in my eye yet,

Well, what is your problem then?

Donkey11 20-12-2010 17:18

Where is the problem? I wrote what to expect with this option, and then let them think for themselves.

mr.ttrx 20-12-2010 17:34

quote: Originally posted by Donkey11:

what to expect with this option

From whom to expect? normal person will react to this normally.

Der Alte Hase 20-12-2010 18:13

And how many normal people have you seen among us?

Anton INS 20-12-2010 21:26

Okay, it seems to me that the topic has been exhausted, thank you everyone!

mt1000 20-12-2010 21:27

I don’t rule out that there are some who will rush naked into a Kruzak driving along a pedestrian path, at first it’s fine until they hit you in the forehead with a door - it doesn’t knock the crap out