TK's Emisar D4 review

Wellā€¦ itā€™s hard to say something without fitting components and power calculation, obviously there wont be too much lumens using boost or buck driver. Yeah, a lack of place is limmiting driverā€™s opportunities. But comfortable interface and rich functionality thatā€™s what can make a real wow effect.

As for Indigo, everyone can use source code without any restrictions. Thereā€™s no licence but author is not against, in simple words - do what you want :slight_smile:

Test 4 looks like the best regulation, it goes to a steady level fastest. And well done in preventing oscillations!

Is your thermal algorithm specifically working well in this host or would it work just as well (without oscillations) in bigger hosts?

Thanks for the insight Dale and couldnā€™t agree more, but this not off the shelf glow stickers or store bought cloth tape, plastic or vinyl, it is a multi layer heat resistant sort of tape capable of withstanding heat to 500C or very close to it, Kapton heat range is only about 280C, the luminescent pigments is in between heat shielded materials, and it all can be easily removed, well sort of easily, depends how long itā€™s been on as the current adhesive seems to harden with time and the heat I think, generally easily removed by tweezers and then a low grade solvent or alcohol and q tip to remove left over adhesive cling, One material is a 1 mil thick polyimide film in disks, Edit: or in sheet form, and is just short of being actual Kapton being itā€™s short of the polymers used in actual Dupont Kapton tape then with the silicone adhesive application to bond the layers, and one other layer is PTFE with Teflon then with the luminescent pigments I place in between the layers it works fantastic but time consuming to make and expensive so really only barely practical, it does not melt even when testing it with my jewelers torch (Little Smith), also make glow O rings with hybrid silicone tubing and my own mix of pigments, injected, measured and sealed, and that is also heat resistant as well but not to the extent of this tape, yep have melted a few stickers, tapes, cloth in the process of trying to figure out what works and what doesnā€™t, there are some very bad products that will melt almost immediately so people need to really search for heat resistance 80C min. if using glow anything in lights for sure, I couldnā€™t agree with you more Daleā€¦Thanks

It looks like the driver cavity is about 19.3 mm inner diameter and about 2.5 mm deep. The tiny85 is the tallest component, at about 2.0 mm, which leaves 0.5 mm empty space to the shelf. In theory, Hank could make that 0.4mm or 0.5mm shallower to speed up thermal regulation response, but there might not be enough room for the wires.

I agree the UI can make a huge difference. Thatā€™s why Iā€™m excited about the firmware being fully open-source. It can have any UI you want. :slight_smile:

Does this mean Indigo is public domain? Usually ā€œno licenseā€ defaults to ā€œcopyrighted with all rights reservedā€, legally. But if the author states that it is released under public domain or CC0, I can include it in the repository.

(note: ā€œpublic domainā€ and Creative Commons Zero ā€œCC0ā€ are equivalent)

I suppose I could include it anyway, but it would still need a clear license of some sort. For example, I have DrJonesā€™ luxdrv which is CC-BY-NC-SAā€¦ even though the NC (non-commercial) part causes trouble. The NC part means I canā€™t even look at the code without risk of being sued, because people sometimes sell the stuff I make.

Always wondered what keeps scoundrels in the light industry from just hanging back and watching your fantastic R&D along with many other fantastic advancements that have came from this group then take it and tweak it to their purpose and then use it commercially, seems all they have to do is make some slight tweak and call it their own and register it as such, probably already happens, sort of like watching Manker make such great use out of the driver used in the A6 on, seemed almost every light Manker designed after the A6 and BLF SE X6 & X5 all used those drivers, perhaps some deal was struck way back when,

Nice work TK. :+1:

If I understand correctly, what I have is the first production run. The second batch, I think, will have some firmware updates based on what Iā€™m doing.

Itā€™s pretty nice, but in the first batch you should manage the temperature yourself instead of relying on the built-in thermal protection.

I donā€™t expect a driver retaining ring. It would make the light longer.

Normally Iā€™d be more upset about the driver glue, but it wasnā€™t difficult to remove and didnā€™t really make modding any harder in this case.

The switch PCB is not easily accessible. I havenā€™t attempted to remove it. However, if you do manage to get it out, the driver already has an unused pad to control an indicator LED. This makes it compatible with Narsilā€™s indicator features.

If I understand correctly, thatā€™s what Iā€™m doing?

Iā€™m calibrating it for this specific host, but I plan to try it on a SRK and a Convoy triple tooā€¦ the idea is to update bistro and crescendo with the same algorithm, and maybe Narsil if Tom is okay with that. If things go well, it shouldnā€™t need much (or any) modification to work in different lights, but that might be overly optimistic. It does at least adjust proportional to the rate of change though, so it will react slower on lights with less power or more thermal mass.

Anyway, Iā€™m not done yet. I hope I can get it to produce a nearly-flat runtime graph for the whole life of the battery, aside from the initial hot peak. It looks promising so farā€¦ like, on that last graph, I changed hands to give it a fresh heat sink, and about 15 seconds later it stepped up a bit.

Itā€™ll be interesting to try this underwater, or touch it with ice mid-test.

Oh, also, tiny85 chips donā€™t use a calibrated sensor. They vary by at least 10 C between individual pieces. So I think I need to convert that thermal toggle function into a thermal calibration function like in bistro.

There are reasons I use a GPLv3 license: The GNU General Public License v3.0 - GNU Project - Free Software Foundation

Some very skilled lawyers created that license specifically to make sure free software wonā€™t be abused. People can make and sell derivative works, but they canā€™t just take ā€” they have to give too, by releasing their changes under the same license. Thatā€™s the foundation of the whole free software information economy. Share and share alike.

What tape is it? I could use some.

That is interesting TK, thanks, always wondered but should have figured that if I am wondering there are lawyers making sure there is no wondering about it, that is great.

Agro, I make it myself but I donā€™t sell it, itā€™s still work in progress but fairly good at where it is at the moment and the O rings I make as well, got real tired of trying to find GITD O rings so made my own and they are a 1000 times better than any store bought just not as easy to work with or convenient, lots of work just to make one ring and then measure for fit and install, easy hour work.

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

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

I think itā€™s nesessary to replace spring to a brass pill. Cutting down the driverā€™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, itā€™s more a toy than a serious develop, as author says. He doesnā€™t want to licence it, who would have thought but pirates must rejoy :slight_smile: Seems that in your country thatā€™s really hard to sell something without following intelectual property laws. I understandā€¦ 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:
(itā€™s over-sampling and using noise to slightly increase the resolutionā€¦ which may sound silly, but it improved the results so Iā€™m keeping it that way)

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

I measured 20.40a at the tail with vtc6ā€¦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 pulledā€¦ I was guessing about 15A, so itā€™s even higher than expected. That works out to like 75W. I added this info to the review, since I donā€™t have tools to measure that many amps.

^ A 75W incandescent bulb is actually pretty brightā€¦ Dangā€¦ :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 isnā€™t safe to handle after 10 seconds. I think Iā€™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 userā€™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 didnā€™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.