Talk about future projects and donation topic

There’s the Nichia 319A which has a hexagonal die.

But wasn’t there talk of a plan for a dual lens zoomie?
That could be a fun challenge.

The circular CBT90 and CBT140 are not COBs, it is a single LED, and they are about as efficient as cree LEDs.
The only difference is that instead of being 6 or 12v they are 3v and much higher current.

Yes Jerommel, when a zoomie is done as BLF special I have something to do with it can only be a tad strange, so double lens or some sort of wavien thing.
I have seen your Brinyte and have a Jaxman Z1, no point in making a regular, those are available in good quality already :smiley:

I’m not sure if the BLF Lantern project is still on your table as a future project, but many would still like to see that be added hopefully in the future.

SBT-70 is not a COB.
According to Luminus CBT-90 is a chip-on-board LED

CBT-140 is a COB too.

As to efficiency, if I read the datasheet correctly, the top bin of CBT-90 does 2100 lm at the rated current. That’s 9A. At this current Vf is 3.1 V. So 75 lm/W. In Texas Ace tests of XHP35 E2 bin we see the same output with c.a. 100 lm/W. There’s HI E4 available.

ADDED: that said, I’d love to see a big thrower based on CBT-90.
ADDED: though probably compact 3*18650 package is (by far) not enough to make it thermally stable at high output.

Yes I saw your post.
I had hoped Barry and you would have kicked it off.
Charging, interesting head
Could it be done in such a way the head Lego’s with the Q8?
Maybe some sort of jumper so we could do this one with the long tube 2S for long runtimes. Adjust jumper and use it with the normal Q8 or short ST tube?
Though a really good diffuser (with inverted shining cone surrounded by frosted white) that screws on the Q8 instead of bezel would make it a lantern but missing the smart design features you made.)

Just thinking out loud here :wink:
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Those luminous LEDs, only the 140 seems round. 21A is a good match with the Q8 driver though, are they as expensive as the SST were/are?

” Chip on board package assures straightforward system assembly with the best
possible thermal performance for high power devices.”

This is referring to the fact that the LED chip comes attached to the MCPCB board.
It is not a “COB” type LED that has multiple blue LEDs underneath a phosphor layer.

This is a real COB:

This is a single die LED with a sound shape:

I never hear much from Barry. (i don;t remember who that was. :P) im not sure about the high amp output of the Q8 driver would work with a continuous-running lantern head. The main concept and ability of the lantern design is to have a warmer white output that creates less eye glare, a warmer tone & higher CRI for lantern use, added with substantial long run times even on maximum mode, compactness for storage, ability to run on 1, 2 ,3 or 4 cells, have built in regulated parallel charging (that can charge from a solar panel in off grid locations) etc. If i had a Q8 sample to work with and modify, i could probably start from scratch on a re-worked second lantern prototype based on the Q8 body and its driver with all its modes, but at a reduced current to increase run times.) (and add charging ability)
Below is the current prototype still being battered hard and used & performing as the best LED lantern i ever used, here on a mountaintop expedition we did back in July in a mountain range on the Atlantic coast:

I like to do tests so I will be happy If I can help the future projects with some homework. :smiley:
The convoy and Q8 thread compatibility is a good idea.
Also a very small light I think would be better with 18350 than 16340 because now we have the Aspire 18350 as a decent high drain cell but I can not name much good 16340.
I can measure lumens, Intensity, temperature, current, voltage. I can solder and put together a driver so you can count on me in if need to do some experiment on future lights :sunglasses:

Thanks for the info.

DBSAR, yes you are right, sorry for again talking about a simple diffuser.

So a Q8 tube compatible head
Driver with less amps then Q8
Single warm led
USB charging.

It seems a driver like the ST needs but with less 7135 chips and charging chip

Of course in your proto the total length is more then needed, since you build on a SRK.

You had an inverted reflector/cone planned for sideways light right?

Powerbank function?
Charge the lantern with a solar panel and at night cherfe phone and or speaker.
Ample space and more versatile.

Maybe cool to do ST and lantern at the same time aiming for early summer for finishing the lantern.
You have a Q8 ordered?
Not a red lighted switch but green acting as beacon.

Definitely add a charging chip to the driver board, maybe a TP4056 chip type (as integrated designed by someone who has that capability) and indeed a USB power output is a possibility too as the lantern runs from four 18650 cells in parallel. (using four 3500mah cells would give it a 14000 mah charging theoretical capacity?) I already thought about adding a separate “glow” led to the switch boot on the prototype, based from the circuit design from the Steam Pipe light glow tube, ( which has been running for the last few years on the same pair of AA batteries) meaning from the lanterns batteries the drain would unmeasurable.
edit: I did order one Q8 , ( but they say its on back order now) but that Q8 is to use as a flashlight. (not going to butcher that one for a lantern prototype.

Added I will be building a “jig” to hold the 30Q cells in this week coming, and wired with #12 guage wire and 20 Amp switch to run the tests on the 30Q cells.
(tests will be scenarios that could happen in a 4-parallel light like the Q8 or SRK, will include:

- one fully depleted cell dropped in the parallel circuit with three other full charged cells

- one full charged cell shunted in the circuit in reverse-polarity against three other full charged cells. (if all cells survive the first test)

  • other tests open to suggestion if any cells survive. :slight_smile:

A bezel swap or plug-in diffuser would change the Q8 into a lantern it seems. Ramping lets you adjust the brightness (and runtime), charging and PB feature could be an add-on ‘ring’ in between the batteries and the head…

Maybe there are efficiency issues i don’t understand though… but it seems a Q8 is a good base. Why build something very similar from scratch again?

Yes, a good lantern is on my wishlist. Still using the Coleman fuel one as tthere’s no good battery alternative.

Stated like that it seems doomed indeed.

But i am not suggesting any one company to design and produce a whole set of components just like that. I merely point out that if ‘everybody’ would comply with some ‘agreed upon scheme and interface set’ then a lot of lights would have compatible parts, to the point it would be easy to produce new lights with just a part swap, likely the head. Do you really need another 18650 tube or tail cap when you can pick one already designed and produced?

It is a bit disturbing to see that most lights from a single manufacturer won’t lego… but then that may actually mean it is effectively impractical - for the reasons you point out.

Regarding BLF lights, i imagine planned compatibility between parts when possible could only help future projects.

The CBT-140 ist very inefficient!
Both LEDs have been superseeded by the new CFT-90 which is much better, but still not as efficient and cheap as Cree LEDs. They all have very low thermal resistances though, making them much better suited for high wattages.

I have have spent some time thinking about putting a CFT-90 into my BLF GT. Conclusion: it’s a cool idea, but very impratical and extremely expensive. The GT is also actually too small to adequately cool the LED at for example 35A (120W) (I think it will go at least this high). After 10min the LED would already hit around 144°C (based on thermal analysis in the GT thread and the thermal resistance of the CFT-90).

I have found a better alternative with similar performance, but higher efficiency and practically free in comparison.

Not really, 60lm/W is about the same as my XHP70 is getting when driven at 12A.

The CFT90 is also square, so that’s no fun…

I just calculated the effciencies.
The CBT-140 (14mm^2) in it’s best available Bin (UA) @90W (25A) & 85°C will do 4122-4430lm, 46-50lm/W, up to 100cd/mm^2.

The XHP-70 P2 (28.75mm^2 with dome) will do around 6780lm @ 12A (92W) @85°C, 72lm/W (see test here, I added 12% brightness for the P2 Bin). De-doming it will make it the same size as the CBT-140 and reduce the brightness a bit. The driver of the XHP-70 will probably be more efficient and much, much cheaper because of lower currents.

The XHP70.2 P2 has basically the same brightness, but has a higher efficiency because of the lower Vf.

Wow, but a zoomie would benefit from a round DIE
Even hexagonal is better to look at then a square IMHO