*BLF LT1 Lantern Project) (updated Nov,17,2020)

[sbslider]

@DavidEF

Even 5mA is well into the territory of “Moonlight” mode. 60mA is insane!

My D4 running Anduril is 2.1mA at the bottom of the ramp, with my Lexel aux board also. With just the aux board running, which is barely enough to navigate around my house at night, it is less than 1mA. At the bottom of my stepped range, its 4.7mA, which is super easy to see anywhere in my house. I use this when I want to illuminate a safe lock at my work. 60mA is ridiculous!!!

[Madtoffel]

I don’t know how bright you all want the switch/ auxiliary light to be, but does the cri even matter at a sublumen brightness level, since the human eye can only see b/w in very low light conditions?

[SIGShooter]

Here are the additions since 4/28. Don’t forget to check your name in one of the linked spreadsheets if you haven’t already done so.

1420 Toglud
1421 Keisari
1422 Keisari
1423 BobG
1424 Martinc5618
1425 Martinc5618
1426 DAGG3R
1427 MRsDNF
1428 MRsDNF
1429 jon7
1430 Ironhorse
1431 Th558
1432 Yummy Yam
1433 m0nk33
1434 Edindevon
1435 Thrust84
1436 cvaty
1437 mikewilzn
1438 mountainair26
1439 mountainair26
1440 tocirahl
1441 jeep157
1442 bquinlan
1443 Fat_Head_Carl
1444 Light
1445 pthartung
1446 amishbill
1447 darrylo
1448 darrylo
1449 ossifrage
1450 PabstyLoudmouth
1451 hcanning
1452 Tjbchs
1453 Pierre
1454 seriesone
1455 dubyrunning
1456 Nicolaas
1457 Klayking
1458 ligonw
1459 amars7
1460 808Hi
1461 808Hi
1462 braino
1463 Juls Boo
1464 7pot
1465 ViperAUG
1466 mugs
1467 mugs
1468 Kahuna
1469 Razors84
1470 heysquanchy1916
1471 Marcello
1472 Dawged
1473 jknut
1474 Dougdimadome
1475 NiceU
1476 NiceU
1477 dmbaty
1478 dmbaty
1479 TrueNerd
1480 Mr.Poppy
1481 Mr.Poppy
1482 Mr.Poppy
1483 cu42
1484 cu42
1485 blammergeier
1486 blammergeier
1487 Pöbel
1488 Pöbel
1489 KalmJ
1490 cm64
1491 Petroleum Lantern Guy
1492 Jinx
1493 charwinger21
1494 EricJ2190
1495 EricJ2190
1496 NMJoe
1497 NMJoe
1498 Tldd
1499 SvenWalker
1500 Caboose
1501 shooter52a
1502 Attackhorse
1503 Big_Sam
1504 will34
1505 snakesnakington
1506 Mr Excitement
1507 lmcmann
1508 lmcmann
1509 D10ten
1510 beastlykings
1511 beastlykings
1512 Klocknov
1513 bc777
1514 Stereodude
1515 Hiatus1r8
1516 azuretan
1517 ossifrage
1518 ossifrage
1519 magnet
1520 B0Y1L4W
1521 rockmonkey4004

[DBSAR]

@Madtoffel

I don’t know how bright you all want the switch/ auxiliary light to be, but does the cri even matter at a sublumen brightness level, since the human eye can only see b/w in very low light conditions?

For the switch “glow night light” CRI is not important at all. What is beneficial, is to keep it in the yellow/amber color spectrum as a night moon light/firefly glow in the range where it do not upset the circadian rhythm for sleep, while blue/green spectrum light radiation reduces natural melatonin production in your body.

[ToyKeeper]

@DBSAR

For the switch “glow night light” CRI is not important at all. What is beneficial, is to keep it in the yellow/amber color spectrum as a night moon light/firefly glow in the range where it do not upset the circadian rhythm for sleep, while blue/green spectrum light radiation reduces natural melatonin production in your body.

Mostly, yellow doesn’t attract bugs as much.

The blue light melatonin thing can be misleading. A 2700K light at 100 lumens contains a lot more blue light than a blue button LED at 0.1 lumens. Even though it looks yellow, it has a bigger impact on sleep than a blue button.

[SKV89]

For me, I leave on my 2000k Tiara Pro at maybe 20 lumens when I stay at hotels. Does not affect my sleep unlike cooler cct lights. My sleep quality is generally very sensitive to light. Perhaps a 2000k indicator light that can serve as a firefly night light might be nice.

[Wieselflinkpro]

Is this the driver of ghe LT1?

https://www.aliexpress.com/item/Sofirn-C16-Flashlight-Driver-Board-48-5mm-4-2V-Led-Light-Driver-5-Modes-Lanterna-Lamp/32887892375.html

[Agro]

@DavidEF

@djozz

It is nice to see them next to each other

I agree that the shorter shade on the V2 looks better. Sofirn may be still in a design stage that the shade can be shortened a bit? You can always ask, and a shorter lantern is an advantage.

About the switch-leds: I have done a quite comprehensive search for all kinds of micro-SMD leds (0403, 0603, 0805) for use in lighted switches and I can report that a good warm white is not on the open market, although Sofirn as it is based in China may find sources that I can not access. The warmest are 2700K and are a low CRI ugly tint. There is one led from Nichia that is 2700K 80CRI and nice tint (Nichia NSSLT02A, I have a few of those) but that one is fragile, with a thick silicone cover that is easy to knock off, you do not want it near a moving switch and cap. Also a phosfor-converted amber would be nice but I have never found those in the small leds category either, the smallest is the PC-amber Nichia E17A, a bit too luxurious for a switch led.
Instead you may want to settle for red or orange, with red being a more efficient led (may not be so relevant in this application with 4 big batteries, runtime is forever anyway).

I wonder if Yuji could be convinced to make a tiny high CRI very warm white emitter for us. With over 1400 on the list, and two emitters per switch, we’re already close to 3000pcs. That seems like a respectable order size to me, but it depends on whether they already have tooling and equipment to make such small emitters and whether they are even interested. If they can make 5mm leaded package LEDs, they should be able to make tiny SMDs too, right?

Yuji makes SMD LEDs already, 5730 and 2835. The site throw 404s so I can’t link to them directly. I have datasheets at hand - they go down to 2700K. But why Yuji? They don’t seem any better than Optisolis to me. Am I missing something?
As to reasonable order quantities….I remember reading some guy who tried to get a batch of custom LEDs manufactured.
Minimum order quantities were in the millions. With one exception - Nichia.
I tried to find that post now (it was some blog I think) - and I failed. That’s sad, it was a nice read.

[fneuf]

@fneuf

The more the CRIs, the merrier!

@DBSAR

@Madtoffel

I don’t know how bright you all want the switch/ auxiliary light to be, but does the cri even matter at a sublumen brightness level, since the human eye can only see b/w in very low light conditions?

For the switch “glow night light” CRI is not important at all. What is beneficial, is to keep it in the yellow/amber color spectrum as a night moon light/firefly glow in the range where it do not upset the circadian rhythm for sleep, while blue/green spectrum light radiation reduces natural melatonin production in your body.

I misread the posts, I thought was discussed the main warm leds. Indeed, tweaking the CRI criteria of the LED of a switch is plain überluxury, probably overengineering, and mainly unuseful to the enduser.

That said, at this state, what are the aimed official CRIs levels for the LT1?

[Pöbel]

wasn’t the LT1 supposed to have many AMC? So this cannot be it.

[weklund]

I am in for two, please.

[Madtoffel]

I don’t know where the idea that we are using some random aliexpress driver is coming from, but we are using a custom made driver desigend by Lexel. You can find pictures of that on the buttom of the main post on the first page.

[Kingjohn]

I am in for another one!

[Tally-ho]

@Wieselflinkpro

Is this the driver of ghe LT1?

You can see the LT1’s driver (prototype) in the first message of this thread.

@DBSAR

Barry from the factory have provided a photo of the new LT1 BLF lantern driver ready for the firmware for the lantern!

[DBSAR]

@Pöbel

wasn’t the LT1 supposed to have many AMC? So this cannot be it.

It will have 7 AMC 7135’s per channel. ( total of 14)

[iamlucky13]

@Agro

Yuji makes SMD LEDs already, 5730 and 2835…But why Yuji? They don’t seem any better than Optisolis to me. Am I missing something?

All of those - 2835, 5730, Optisolis - are overkill for indicator lights - capable of significantly more output that is needed, and with a cost the manufacturer won’t be favorable toward. They might even be large enough to be a packaging challenge for a button PCB. The whole PCB is maybe 8-10mm across. After providing room for the button itself, a 2.8mm wide LED looks really big.

Youtube still showing Q8 indicator PCB
Full Youtube Video of indicator LED swap

@fneuf

Indeed, tweaking the CRI criteria of the LED of a switch is plain überluxury, probably overengineering, and mainly unuseful to the enduser.
That said, at this state, what are the aimed official CRIs levels for the LT1?

Worrying about 90 CRI vs 80 or perhaps even 70 CRI like we often do for primary emitters, I’m sure is getting carried away.

Between a monochromatic or even phosphor-converted amber emitter, and a very warm white, I’m not so sure, despite the low lumens.

My wife has several different types of electric “candles” with some form of amber LED. Even the glow of the candle itself, not considering the illumination of nearby objects, looks non-candle-like to me.

I’m not advocating one way or the other. Just suggesting I think there would be a visible difference between those options.

[DBSAR]

@iamlucky13

@Agro

Yuji makes SMD LEDs already, 5730 and 2835…But why Yuji? They don’t seem any better than Optisolis to me. Am I missing something?

All of those - 2835, 5730, Optisolis - are overkill for indicator lights - capable of significantly more output that is needed, and with a cost the manufacturer won’t be favorable toward. They might even be large enough to be a packaging challenge for a button PCB. The whole PCB is maybe 8-10mm across. After providing room for the button itself, a 2.8mm wide LED looks really big.

Youtube still showing Q8 indicator PCB
Full Youtube Video of indicator LED swap

@fneuf

Indeed, tweaking the CRI criteria of the LED of a switch is plain überluxury, probably overengineering, and mainly unuseful to the enduser.
That said, at this state, what are the aimed official CRIs levels for the LT1?

Its practically pointless to worry about applying or using hi-CRI emitters for the switch, as its just a glow, to use as a very dim night light or indicator for locating the lantern switch in the dark. its planed intensity of less than a lumen (or less than 2 or 3 milliamps) is just adding unnecessary cost and delays to the production model. From my tests a dim glow of a orange or yellow LED does the trick quite well.

Worrying about 90 CRI vs 80 or perhaps even 70 CRI like we often do for primary emitters, I’m sure is getting carried away.

Between a monochromatic or even phosphor-converted amber emitter, and a very warm white, I’m not so sure, despite the low lumens.

My wife has several different types of electric “candles” with some form of amber LED. Even the glow of the candle itself, not considering the illumination of nearby objects, looks non-candle-like to me.

I’m not advocating one way or the other. Just suggesting I think there would be a visible difference between those options.

[staticx57]

Maybe this will explain why amber is a poor stand in for an actual candle

Black Flat Yellow not white flat amber

black flat yellow

xnova

flame

[iamlucky13]

Cleaning up the formatting of the above, quite satisfactory response from the lantern guru himself for easier reading.

Also, to further clarify what I was getting at: I think a very warm (<2200K) white indicator of any CRI will have a different character than an orange/yellow/amber one, not that it is necessarily better suited for the purpose. Also, based on djozz’s post a ways up, this tangent might be moot anyways.

@DBSAR

@iamlucky13

@fneuf

Indeed, tweaking the CRI criteria of the LED of a switch is plain überluxury, probably overengineering, and mainly unuseful to the enduser.

Worrying about 90 CRI vs 80 or perhaps even 70 CRI like we often do for primary emitters, I’m sure is getting carried away.

Between a monochromatic or even phosphor-converted amber emitter, and a very warm white, I’m not so sure, despite the low lumens.

My wife has several different types of electric “candles” with some form of amber LED. Even the glow of the candle itself, not considering the illumination of nearby objects, looks non-candle-like to me.

I’m not advocating one way or the other. Just suggesting I think there would be a visible difference between those options.

Its practically pointless to worry about applying or using hi-CRI emitters for the switch, as its just a glow, to use as a very dim night light or indicator for locating the lantern switch in the dark. its planed intensity of less than a lumen (or less than 2 or 3 milliamps) is just adding unnecessary cost and delays to the production model. From my tests a dim glow of a orange or yellow LED does the trick quite well.

[iamlucky13]

@staticx57

Maybe this will explain why amber is a poor stand in for an actual candle

Thanks! This is cool data to see!

Was the camera used for the photos in auto white balance?