TK's Emisar D4 review

Any chance of selling an optional 18650 body tube with knurling on it?

I like the added grip knurling provides. I’m not a huge fan of completely smooth tubes.

I think it’s nesessary to replace spring to a brass pill. Cutting down the driver’s metal border or even more could help to win a few mm. Also a good idea to drill the hole in the pcd for inductor or make the existed hole wider under the led star in the center specially for inductor (must be something like direct connect with mcpcb) and make the other ones for wires.

The code is far from being perfect, it’s more a toy than a serious develop, as author says. He doesn’t want to licence it, who would have thought but pirates must rejoy :slight_smile: Seems that in your country that’s really hard to sell something without following intelectual property laws. I understand… so if there were a licence, that would be the best solution. I may not know all the aspects but you have the source code. Who prevents you from licensing it by yourself? Who cares?

BTW, part of the difference between Test 3 and Test 4 was a cheap trick: The attiny85v has a thermal sensor and 10-bit ADC. So, I made it give me about 11 or 12 bits of precision. :smiley:
(it’s over-sampling and using noise to slightly increase the resolution… which may sound silly, but it improved the results so I’m keeping it that way)

Just got my D4 (Nichia) in today. Here’s a size comparison with the ZL SC600w MKIII HI.

I measured 20.40a at the tail with vtc6…this thing is a hot rod!

Thanks for the review and work on the F/W TK!

Seems like an awesome light that will blow the S41/E14 out of the water.

Just hope it will ship with 90+ CRI 5000K 219C as an option.

Thanks! I was wondering how many amps it pulled… I was guessing about 15A, so it’s even higher than expected. That works out to like 75W. I added this info to the review, since I don’t have tools to measure that many amps.

^ A 75W incandescent bulb is actually pretty bright… Dang… :smiling_imp:

A german online-shop lists them for a reasonable price. Do you want me to send you two pieces ?

The head of the light isn’t safe to handle after 10 seconds. I think I’ll use GA cells instead to get more runtime/less heat.

Someone should make a light like this with a plastic or rubber cage round the head. The cage should be sufficient to prevent the user’s fingers from directly contacting the metal in the head, while having slits to allow heat to escape.

Getting too hot to touch in 10 seconds sounds a lot like my modded DQG Tiny III 18650 with FET driver. It became such a problem that I made an external finned aluminum heatsink. Even that didn’t solve the problem, but then I painted the heatsink with paint and super-glue and installed a new button cover made out of Sugru. The light still gets too hot to touch, but now takes more like a minute to get there instead of 10 seconds. The finish on the light looks awful though.

Here’s a picture with the 18350 tube. It’s almost the same size as the 4sevens mini turbo mkii!

Measured it with Aspire 18350 and it pulled 13.7A. Impressive.

Thank you TK for your nice and useful review! :+1: I like the green one. :smiley:

The road has led you to an interesting place — welcome to BLF!

It’s not often that anyone spends their first post on one of my threads. :slight_smile:

After a couple minor tweaks, I tried a runtime test on turbo with a full 25R cell until LVP kicked in.

I had the thermal limit set to 45 C (ish) and pointed a fan at it the whole time. Output stayed fairly close to a stable level after the initial peak, but it actually got slightly brighter over time overall. I suspect this might be due to the cell voltage getting closer to the emitter Vf, so there may have been less heat. Toward the end it also becomes very clear that the thermal regulation is fighting against the typical direct-drive sag curve.

So… aside from being a little bumpy, thermal regulation seems to be working pretty well.

Output is about 900lm with active cooling. Could you also measure output with out cooling?

It would be nice if you posted the link in here

Test 5 looks great! And yes, a version minus fan cooling and plus hand cooling seems most realistic to me. And given the nature of this light (hotrod) I would not mind the thermal limit to be a bit over 50 degrees for some higher regulated output.

What kind of stable output are we looking at in test5 btw? My guess would be 600-ish lumen?

Thanks for the fine review.

I prefer the size, tint, beam and UI of the Nichia D4 much more than any of the Manker, Astrolux or similar lights popular here. I rarely use them because the UI just isn’t simple enough for simple me.

Double-click the D4 and you will immediately see more light than you think possible from anything this size. Within seconds it will be too hot to hold.

But use the ramping, and, ah, you can get whatever level is perfect for you.

The Nichia tint and beam are just right for walking the dogs in the dark. The beam is floody and the tint seems neither too yellow or white — but just right.

I am using an unprotected 3500 mAh 18650 I purchased from ZebraLight. Lack of a clip is a nit as is the absence of more knurling. I added the deep carry pocket clip available from Richard for $1.10.

The 18650 body is small but large enough to comfortably hold. I passed on the 18350 body.

Darn good light — eager to see what’s next.

This active-cooling test was just a sanity check to make sure the regulation doesn’t do anything dumb. The 45 C limit was arbitrary. The thermal ceiling will be user-configurable, so you can change its stable output level by changing the temperature limit.

Most likely, the calibration procedure will be:

  • Fast-click 10 times from off, then hold the button on 11th click.
  • Light comes on at a low mode.
  • To disable thermal regulation (or set it to a very high temperature), let go of the button now. Otherwise, keep holding.
  • Light goes up to maximum.
  • Keep holding until the light feels hot.
  • Let go of the button to set the thermal ceiling.

Attiny85 chips use un-calibrated thermal sensors, so a factory default value will be inconsistent. It seems best for the default to err on the safe (low) side, with a config option so the user can set it to whatever they like.

Done. Had been posted there already, though. :slight_smile: