TK's Emisar D4 review

Has anyone thought of building a flashlight with a phase change heat sink?

https://www.1-act.com/led-thermal-management/

Something that would contact the smooth outside of the light and carry heat away from it (better than your hand) would be useful.
Swords with gauntlet hilts that wrap outside of the grip area illustrate how it could work.
https://www.google.com/search?q=gauntlet+hilt+sword&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiejeX8rNLVAhUJi1QKHUUyC-IQ_AUICygC&biw=1106&bih=830#imgrc=zr9y3GNnmppEnM:

Here are some modern-tech designs: http://www.windrosearmoury.com/zc/index.php?main_page=index&cPath=71

That’s what I suspect as well. Got 50 a couple of times and 51 was clearly different.

I took D4 for a short walk (buying flashlights is good for health!), have some things to report.

  1. Like said already many times, knurling is missing.
  2. I noticed a quirk in the UI. If I ramp the light up to a fairly high level, wait for thermal management to restrain it an start ramping again, I expect the light to smoothly change output. It jumps to the previously set level and starts ramping from that.
  3. A weird software bug:
    Sometimes the light doesn’t notice that I cut off the power. It doesn’t blink on power-on and doesn’t reset mode to 350 mA. Happened twice accidentally, I couldn’t reproduce. Then after playing some I tried to do it again and it happened: there were no blinks. But then I noticed more: now I can reproduce it at will, it happens every time. I think this may be because I have not turned the light on since it happened, there’s some flash state that makes the light not notice and turning it on resets that.
  4. I like the tint.
  5. Very floody, but still less than I was afraid of.
  6. Everybody knows it, but the output is good. :slight_smile:

I thought about that. There could be a minor LED temperature improvement by replacing solid trays with vapor chambers. Or actually large portions of head. It could also make powerful lights (D4 counts) slightly shorter. Likely too expensive to be worthwhile.
You could use heat pipes to spread heat over large heatsinks. It could make them more effective, making monster lights a bit brighter.
You could also use something like paraffin wax to increase thermal capacity and thus increase turbo duration.

wondering if anyone really only spent $40? Add batteries, spare tubes…. :wink:

Ha ha good point! Well i spent $42 with the tracking , think I may be the only one with no 18350/18500 tube though………….for me the 18650 is compact enough and it eats through one of those fast enough :open_mouth:

:+1:

Same here, only standard 18650 format. But I did get all three colours though. Interestingly I like all three colours, and I’m glad I got them all.

18650 only for me as well. It does eat juice like its free. small enough to loose already!

Also, we’ve got 3 reviews on MTN!!!

Yes one of them is mine…(pops collar) :wink:

Mtn was out of Green 18350 tubes last week.I hope they they get some in soon so i can try out these new aspire 18350’s i have.

Well, the heat sinks made for RC engines would clamp onto the smooth flashlight surface, with a dab of thermal goop:

https://www.google.com/search?q=model+engine+heat+sink+clamp

I wonder if there’s a way to use the waste heat — does anybody make micro- or nano-sized Stirling engines?

Yikes let’s keep it PG.

lol! :smiley:

Can this take Olight batteries?

I would stick with unprotected flat tops. Keep your springs in good shape.

From OP

Maximum cell length: 67 mm
(protected cells may not fit)

Battery: One 18650, 18500, 14500, 18350, or 16340 cell (with matching tube)

From me
goofy proprietary cells designed to not work in normal lights (no)

Yes. I’m using button top GA now, but definitely prefer, and feels better using a flat top cell.

LOL, ignorant me did not intend my remark that way, I will remove it!

Isn’t protected safer though?

Generally yes, but protected cells often don’t work in a light like the D4. There are two reasons:

1) It just doesn’t physically fit. Either it’s too thick, and/or it’s too long due to the protection circuit. The D4 probably won’t contact when tightening the tailcap.
2) 99% of protected cells are going to trip most likely due to the current that’s too high. Only recently you have 15A protected cells; those might work… if they fit… But they probably don’t fit anyway.

Haha. I figured. I had to say it still. Lol.