Talk about ... flashlights?

    Greetings,% username%!
    This is a small educational program on the current state of the portable lighting industry.
    Disclaimer
    I have nothing to do with the lights shown and the rest of the hardware. This post is not their advertising.

    Let's go, let's start with modern LEDs

    LEDs


    Today, Cree LEDs are the most popular.
    They have by far the best Lm / W ratio and at the same time have excellent neutral and warm options, including those with high Cri . True, with regard to “warm lamp light” and high Cri, here not so long ago diodes from the Japanese company Nichia appeared on the market, which, according to reviews who saw how they shine people, give out just wonderful light (neutral / warm, Cri> 90) Suitable even for permanent use at home.
    Of course, so far the “warmer” the lower the efficiency of the diode. Therefore, in the lanterns, cooler or neutral versions are used.
    At the same time, even a cold Cree in a cheap flashlight will be much more pleasant to look at and much, much brighter than your old LED watering can.

    So. Of the diversity in modern flashlights in 99% of cases are Cree diodes or XP-G / XP-G2

    or XM-L / XM-l2 .

    Those with prefix 2 are built on the new SC³ technology and give out on average 10-20% more light than those without it.
    In particular, one XP-G2 can produce ~ 500 lumens at ~ 5 watts. This is the equivalent of a 50W incandescent bulb.
    And one XM-L2 is about a thousand at ten. This is already a 75-80 watt bulb.

    The size of the XP-G2 / Nichia is only 3.45x3.45 mm. and XM-L2 5x5mm. Honestly, the first time I saw an XP-G roasting to the fullest, I could not believe my eyes.

    Drivers



    All this power must be somehow nourished. This is done by special LED drivers, which are linear, impulse, programmable, and a bunch of other words. In other words, DC-DC converters with MK control.
    For example, in the picture above - a piece of handmade , a pulse driver with a diameter of only 17 mm, providing constant brightness during operation and with an efficiency of about 95-97%. Development and assembly, by the way, Russian-Ukrainian)

    In most Chinese and Russian lamps, there are ordinary linears that smoothly extinguish the diode, depending on the residual voltage on the battery. In lanterns, a more serious driver “drains” out of the battery as much power as possible to ensure constant brightness. Particularly tricky then still go into lowered modes, so that the shutdown was not a surprise.

    Also in drivers such chips as can be implemented.
    • Stroboscope \ SOS (one of the signs of "Chinese")
    • Battery Discharge Control
    • Temperature control
    • moonlight (a mode of very weak glow, which lasts for several months)
    • Programming Modes


    and many many others.


    In this shot from the Oblivion movie, on the rifle you can see the optics of the module with three LEDs, popularly “triple”. The development of this particular light module, by the way, is the work of the Moscow office of Lux-RC (+ their partners from Oveready (responsible for the lamp housing)).
    The flashlight at the beginning of the topic is also designed by Lux-RC. It produces 6,000 lumens with 4 batteries, has active cooling.


    Optics




    Everything is more complicated and simpler here. A typical angle of illumination for LEDs is 120 degrees. In addition, the source of the glow is a square with a side of 3.45 or 5 mm.
    You can collect them in a narrow beam, for example, with a lens. But, linzovannye lanterns are leaky, give almost no illumination, and a very large part of the light is lost in the lenses. Flash-goers do not approve)
    Therefore, if you want quality and range, then you have a direct road to the lights with a deep reflector, for example, the same Thrunite catapult V3, with which Tyoma will go on his next expedition.


    If you need something for everyday needs, then this is more a matter of taste. There are crumpled reflectors and TIR optics, you can get almost any angle of a hot spot / light.

    Nutrition




    All serious flashlights are powered by 18650 lithium batteries (18mm diameter, 65mm length). Today they are the most technologically advanced of all. And they also do not pull the pocket too much.
    For example, the Panasonic NCR18650B has 3400mAh on board, the Sanyo ZTA has about 3000. Also, batteries (with the same Sanyo, Samsung, LG) with a maximum charge voltage of 4.35V instead of 4.2 started to appear. They need, respectively, other chargers.

    From one 18650, a good flashlight can give out 1000 neutral stabilized lumens in an hour.

    Add:
    I forgot to say that there are 18650 both with built-in overdischarge protection (a small scarf on the positive contact) and without it. If such protection is integrated in the lamp, then there is no need to overpay for protected versions. Well, sometimes protected 18650s do not fit into the flashlight, so it is better to clarify this point in advance.

    bonus

    18650 batteries are used in power banks, from which you can power your phone / tablet via USB. For example, here's a 4-battery one.

    Able to give out 2A and in case of using 4 Panasonic on 3400, its total capacity will be about 13500 mAh

    If you are more familiar with the AA / AAA format, then of the Ni-MH batteries, Sanyo Eneloop is considered the best. They have a very low self-discharge and decent capacity. Not the same, of course, as lithium ones, but it is quite suitable for EDC / home duty use.
    With one non- lithium AA, the best flashlights remove about 280 lumens. Such as, for example, SC52w from Zebralight


    There are also AA (14500) lithium batteries, but they are less common and will only go to those lights where it is separately specified.

    Cooling



    Perhaps the most difficult moment. Not all manufacturers are thinking about high-quality heat dissipation for flashlights.
    (The FL33 lamp in the picture above is a pleasant, but rather expensive and exclusive exception)
    Strong LED heating leads to a decrease in the light flux and its gradual degradation. Also, this is not the most pleasant way affects the electronic filling. This is not very critical if you "fry" the diode not for a full and not very long time. But in general it will not be superfluous to read reviews and reviews on relevant forums.

    Modifications


    Among flash drives, it is very common to "finish" the flashlights to the functionality they need, such as:
    • Replacing LEDs with warmer / neutral ones or with new generation diodes
    • Modification of cooling. From stuffing the foil inside the “head” to the manual manufacture of copper (and sometimes silver-plated!) Heat sinks specially for the flashlight
    • Replacement \ modification of electronic filling


    Well, that is, everything can be replaced, except for the case. There are even special shops that sell purely cases / heads, etc.
    So, if you are friends with a soldering iron, you can assemble a flashlight for your own Wishlist.

    Tips


    If you just want to understand and see how modern flashlights shine, anyone on XP-G (2) / XM-L (2) with DX and other Chinese stores will suit you. Their brands usually end with “Fire,” which is why they are called “miscellaneous” (only not to be confused with the expensive American SureFire). There you can buy inexpensive (but do not expect quality from them) 18650. Enough for the first time, but in order not to spoil the impression of use, it is better not to save on power and charging.
    If you want something more, then Wellcome to specialized forums like flashlights . Both flash drive and developers hang out there. You can read reviews, see beamshots, participate in holivars and make your choice. Well, or order a custom flashlight, as I eventually did.

    PS
    Thank you for your help in creating the topic
    Forum for lanterns.
    Base for tests / beam shots of lanterns

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