TK's Emisar D4 review

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.

Finally, I receive 18500 tube from intl-outdoor. I like it better than 18350, Tiny size but still have enough length for nice grip! Too bad, there is no good 18500 battery on market right now :frowning: .

(WB 5000K): XP-G2 3D, Nichia 219c, XPL-HI 3A

It can drop down in large steps. Stepping back up only goes one small step at a time though.

The step-downs could be made smoother with a bit more code, but it also has a high risk of introducing bugs. I actually tried it at one point, but the direct approach was too buggy and the indirect approach was fragile. So I went with a more robust but also more visible method.

Also, the regulation is not based on the current temperature, but on the predicted future temperature. This means it’s sensitive to the rate of change. If it’s below the target temperature but rising quickly, it will step down pretty quickly. But if it’s above the target temperature and falling quickly, it won’t step down (and may even step up a little).

When it first turns on in turbo, it will generally exceed the target temperature before it stabilizes. This is because, even with the predictive algorithm, thermal lag still delays the measurements too much to avoid the initial peak. Basically, thermal regulation is rather unpleasantly like trying to steer a fast-moving cow around a hairpin turn on an icy race track. While wearing someone else’s glasses.

Yes, it’s based on the predicted temperature, not the current temperature. This helps it compensate for thermal lag. Without that, the racing cow was slamming into each turn’s crash wall a lot harder.

The light makes a distinction between the actual ramp level and the target level. The button sets the target level, while thermal regulation can change only the actual level. This allows it to step back up when the actual level is lower than the target level and the temperature is no longer too high.

To change the behavior, the ramp button code could perhaps use the actual level instead of target level, when they’re different? I doubt it would be a difficult change… and patches are welcome. :slight_smile:

If I understand correctly, this isn’t a software bug. It means the power wasn’t disconnected long enough for the driver to lose power. To make this happen, do the following:

  • Ramp to a low level.
  • Click to turn the light off.
  • Wait at least 6 seconds so the light will enter sleep mode.
  • Loosen then tighten the tailcap quickly.
  • Notice that the light doesn’t blink. Click to turn it on, and see it’s still at the last-used level.

This happens because the standby current is so low that it is able to tolerate short interruptions while it’s asleep.

I wonder how hard it would be to add an inductive charging circuit in a tailcap. I really don’t like poking holes in a waterproof light for USB ports.

Not that I have an inductive charger… but it might be a nice way to do these things without incurring the usual problems associated with built-in charging.