This was one mighty fine little light. Got mine today and Iāve played some with it. Only problem I see is that it ramps very quickly down from high levels since it get hot.
I also read a thread on laser forum where a guy got a 1watt laser into his eye and got permanent damage. This sounds really scary and I got to think of dangers with powerful flashlights like this and kids. Is it safe to let my kiddo use this? Sheās 4 and really liked this little light, told here to not touch the button on it and use it at the level I set for now and Iām watching all the time. Am I paranoid?
My nephew is 4 and is not allowed to touch my D4. His father does not let him touch his D4 either. He has his own little AA LED light that he uses and feels like itās the same as ours.
Too much potential damage to skin, eyes, furniture, etc, in my humble opinion.
I would do 2+2, I doubt that you would see a difference with only one 3000K in the herd.
I love it, SST20 have a small die so you gain some throw compared with 219C or worse, LH351D.
Iāve tested both, and the SST20 are my favorites, because of the gain in throw.
The tint mix is really nice, but I already like both tints so itās not really a surprise
Hmm, maybe not. I think Iām gonna try it though, mostly because I only have four Nichias to my name, 3 4000ks and a 3000k. Thereās a fourth 4000k in my buddies H03 that Iām gonna swap for a LH351D next time I see him, but that wonāt be for several weeks. I really want a nichia D4, the D4 was my first light that I got before I knew what tint I wanted, so itās a 6500k xpl-hi, no gracias lol.
Some degree of trust is required, of course. People canāt even go outside without being exposed to something dangerous. I mean, some kids stare at the sun just because they can. So this is really something you have to determine on your own, based on how trustworthy your child is.
Almost any LED can cause eye damage if itās running at more than a few milliamps. Staring at a modern LED is a lot like staring at the sun. And almost any battery can start a fire if the user shorts it to itself or something. So I canāt really say any flashlight is 100% safe.
A S2+ with a 3x7135 driver (or, even better, 1x7135 driver) is a lot harder to cause damage with. However, Iād suggest going even smaller if possible. Maybe something with a single AA or AAA Eneloop battery at first.
OTOH, a parentās job isnāt to protect their child from the world, but rather, to help their child explore the world. If they make a mistake and start a fire or hurt themselves or something, itās not necessarily a bad thing, as long as the damage isnāt permanent. It may help them learn caution. Making mistakes is one of the fastest ways to learn, as long as the mistakes arenāt too big to recover from.
TL;DR: It really depends on what kind of person your child is.
Hi TK & all. Looks like Iām getting sucked in to BLF again, at least for a little bit. Thanks for posting!
A:
I apologize in advance for anything Iāve missed in the thread - Iāve only hopped around in it some, there is a lot of good content.
@TK - Something from the OP confused me:
I saw in the OP that youād improved this ~4.5mA figure in Anduril but I couldnāt find a post discussing the improvements or how they worked. I also saw your comment (āā#1570ā:TK's Emisar D4 review - #1570 by ToyKeeper ā) about how the light didnāt go into standby immediately and the next few messages between you and rizky_p explaining that the actual standby drain (as measured by rizky_p) is 24.5Ī¼A and that a project of your eliminates the delay.
I guess Iām asking for more information on the quiescent current / parasitic drain situation.
Do you know whether currently shipping lights have a firmware with low parasitic drain?
Was the move from 4.5mA down to 0.02mA purely a matter of firmware and/or changes in measurement strategy?
B:
Iām also interested in whatās needed (from a hardware standpoint) for a good implementation of something like Anduril, Narsil, or RampingIOS on an FET+1 driver. After reading about it I really want to order an Emisar D4 right awayā¦ but Iāve got a small handful of good momentary switch lights which need drivers and I want to rehab at least a couple of those before buying even MORE flashlights. I have an embarrassing number of non-working flashlights.
As many of you are probably aware I am VERY out of the loop.
Iāve read that a low-value resistor has been added to FET drivers in order to reduce ringing and keep the MCUs from rebooting at high currents.
Iāve read that resistor dividers for momentary button flashlights should use high value resistors to minimize drain.
What do I need in order to get started with thermal regulation?
Iām no expert on the matter but Iād hazard a guess: spot brightness is probably the greater enemy vs total light output. With that said, even 300lumens from a single LED can leave after images that stick around in your vision for hoursā¦ so Iād take TKās suggestions very seriously. In addition to those suggestions maybe you could consider using a diffusing film. eg site:budgetlightforum.com film - Google Search
Driving very large emitters (or multiple emitters) at low currents is also a way to reduce spot brightness. I suspect that you could (safely?) get away with a much higher output if you used a large emitter coupled with a diffusion film vs a single XP-G / Nichia 219 / etc.
A custom low-powered triple or quad might be the cheapest way to get spot brightness down while still retaining a large amount of out-the-front illumination. Or something like a C8 host with DC Fix film with an XP-L or larger-die emitter (such as an SST-series emitter). The C8 gives a large window to apply the DC Fix over.
FWIW Iām interested in this topic as well, although I havenāt really explored it. High powered flashlights are dangerous and Iām uncomfortable with the idea of children using them. Suggestions or explanations of why Iām wrong about spot brightness or how to deal with it are welcome!
Will need to read more up on it. The D4 is def bright. I read that my Maxa Beam does do damage to the eyes but from what I understood that was not because of the intensity but the fact that short arc creates a lot of UV light and not all are filtered out by the glass. The maxa is going to be locked in my weapons cabinet tho as itās def not something for a kidā¦
Iām with toykeeper on the part about parenting. This is why I do let here play with it while Iām watching and explain that itās dangerous to point it directly at someone and that itās very powerful so she can not adjust it with the button. This is teaching here about the dangers but still allowing here to explore. Thereās lots of things that are dangerous when not handled properly so they might as well learn instead of avoidingā¦ But if short therm exposure of the beam can be harmful itās not worth the risk of a kid not listening because there is no second chance with the eyes.
She has weak AA and AAA flashlights but itās more fun to borrow mineā¦
Maybe I should make a separate thread instead off taking this off topic :zipper_mouth_face: ?
I donāt know if itās allowed with links to another forum but this thread below was a good thread to rise awareness about lasers and might be somewhat relevant to powerful leds also so Iāll post it. Mods delete if itās not allowed. This was whatās got me thinking about eye safety. It didnāt have a good outcome but it shows how fast things can go bad.
Small die laser diodes will always be more dangerous than LEDs because of their insane candela/lumen ratio compared to LEDs, especially at long distances. They can do much much much more damage at similar power levels.
Even Iām not keen on the Emisar D4. Its potential for damage, and huge heat generation means itās not a light Iāll be carrying, ever. I prefer a regulated 1000 lumens from a quad LED setup, for very long runtimes of regulated brightness.
Eye damage? Not that Iāve heard of. I have 210 lights and the majority are heavily modified, folks around here know by now that I canāt help but modify a light for all itās worthā¦ never heard of anyone actually having damage from a bright flashlight. Sure, if you look right at it from up close it hurts and you look away, but itās not lingering and causes no ādamageā to my knowledge. Sure arenāt as bright as the sun day in and day outā¦
Adults have to use common sense, Li-ion cells and bright flashlights are not toys for children to play with. Like guns and knives, screwdrivers and wall outlets, common sense must prevailā¦
I was writing about physical damage, like on your skin, your backpack.
And no! Actually, on very close distances, most high power flashlights actually have higher intensity than the sun. This is how I can see my modded BLF Q8 in the brightest part of the day, and when I pull it straight to my face, it gets very hot quickly.
The stock D4 has a standby drain of about 0.02 mA. If I recall correctly, it goes into standby about 6 seconds after turning āoffā.
When the light is awake but has the main emitters off, like between blinks in beacon mode, it uses about 4.5 mA.
The stock lightās moon mode is higher than that, like maybe 7 mA or so. I forget the exact value, but the moon level is higher than I wanted.
In newer firmware, I reduced the power used while awake. To do this, I made it under-clock the MCU at low levels, and also made it go into an idle state between interrupt events. So by reflashing a stock D4 to the latest Anduril, moon mode drops to about 1.7 mA and the between-beacon-flashes power use drops to like 1.1 mA. Also, it goes into standby a lot sooner after going to āoffā mode. In most cases, standby is immediate.
To reduce standby power, you can change the fuses a bit while flashing. Basically, turn off BOD and itāll drop standby from ~0.024 mA to ~0.002 mA. This change doesnāt really affect battery life much though, and mostly just determines whether the light will reboot after changing the batteries, or if it can go without power for long enough to swap the cells.
Iām not sure what exactly was done to eliminate ringing, but if I understand correctly, itās a resistor on the FET control pin to soften the edge of the curve a bit. It may be possible to determine how this works by looking at a recent driver from MtnElectronics or Emisar or Texas_Ace, but I donāt really know enough about circuit design to explain it.
The voltage divider can be eliminated entirely on most 4V linear-driven e-switch lights. There is no need to use pin 7 for that any more. Eliminating this reduces standby drain quite a bit compared to older designs, makes PCB layout easier, and frees up a pin for other purposes. The MCU uses VCC on pin 8 to measure voltage.
To use thermal regulation, at the moment, it needs a tiny25/45/85 MCU with a sensor built in. For running Anduril (or other FSM-based interfaces), Iād suggest tiny85. I plan to add support for tiny84/841/1634 sometime too, but Iām not sure when.
One other thing to note is, for e-switch lights, the UI development is now a lot easier than it was in the past. Take a look at the FSM UI toolkit if you have any interest in making or modifying interfaces. This allows people to define interfaces in a much more intuitive way than before, and makes it fairly easy to support a variety of different hardware.
Also, aux LEDs are a popular thing now. Theyāre blingy like tritium vials, except they donāt wear out and they can be turned off or turned down.
Youāve probably missed other things while you were gone too, but Iām not sure what.
As for lasersā¦ I have a list of ācool toys which are too dangerous for me to ownā, and high-powered lasers are on that list. I could buy or make one, and it would be glorious, but someone would probably get hurt. Many of the high-powered ones are bright enough that even just looking at the hotspot on a wall, without protective goggles, can cause eye damage.