While doing the output/current tests of the 3200K and 5600K version it became very clear that these are different leds, not just a different phosfor. Then I took a closer look and the build appeared slightly different too. At first that made no sense to me, the difference should only be the phosfor. But then I remembered that the 3200K and 5600K batch were purchased with 2 years in between, 3200K in January 2015, 5600K in May 2017, so in between Yuji had changed the design (for the better, as seen in the test) So most likely the 3200K leds in the new Sofirn behave like the 5600K led in this test, apart from the tint.
For the test I thought it would be fair not to cool the leds as well as possible but simply solder them on a common FR4 board, so the heatsinking would not be too different from how the led is mounted inside the flashlight.
Here are the output/current tests:
Directly after the test the leds and led wires felt luke-warm to my lips, nowhere near hot.
This chart already shows that the chosen 25mA is a very conservative current, at 50% or less of the maximum possible output and 30% of maximum current, while most of my flashlight builds are 80% of max output or more.
But to get a hint at longterm stability I soldered the two leds in series and did a 24-hour runtime test at 50mA (so double what the leds will get in the flashlight). Here are some voltage and output numbers of the combined leds in series:
So, nothing exciting is happening here, the leds are fine and show no signs of fading. So unless led death is a sudden event without performance warning, also 50mA is a fine current for these leds.
AFAIC, the suggested 25mA drive current for the flashlight is a nice careful current.
Thanks all for all the input about things I do not know much about, like jon_slider and Noir for info about potting and Noir for driver info. Especially the driver info I will communicate literally to Barry because it is stuff I do not understand myself and hopefully the Sofirn engineers do understand it.
Djozz, thanks for sharing your test. Useful data like this is great to see, especially seeing the improvement both in output and Vf.
I’m also glad to see your test has a good match to a similar test I did with a 3200K purchased in the last 6 months. I can’t measure lumens, but I did see intensity peak at 90mA, with Vf around 3.2V. Here’s my results (along with another user’s CRI data further down the thread): http://candlepowerforums.com/vb/showthread.php?444187-Yuji-BC-5mm-LED-Stress-Test-Graph-and-Images
Even better, you have lumen maintenance results that I have not attempted. It looks like there was a small drop in output over the first 30 minutes as they warm up, and then fairly stable for 24 hours.
That supports a separate plan I have for a little personal project driving 9 of them in parallel at 350mA – as long as I don’t get too much current hogging due to variation in Vf or voltage drop in the wiring.
I hardly ever visit CPF so I had not seen your nice test before, very nice that my result matches yours, and I see that the assumption is correct that Yuji changed to a new make of led between 2015 and 2017.
djozz your test is nice, but it doesn’t show how hot the emitter gets on the inside and how its life expectancy is reduced. I would not overdrive them.
djozz your test is nice, but it doesn’t show how hot the emitter gets on the inside and how its life expectancy is reduced. I would not overdrive them.
No, it does not show that, that is why I called the 50mA test just a hint at longterm stability. Sofirn is going to use 25mA for the AAA twisty which is within the specifications for this led (30mA maximum continuous current).
“History doesn’t repeat itself, but it sometimes rhymes,” Mark Twain
…
After the Apocalypse there will be only 2 things left alive, Cockroaches and Keith Richards
I don’t know much about flashlight LEDs, but it seems like you have a HUGE variation in the performance of the two 5600K LEDs. I know the planned drive current is around 25mA, and the variation there percentage wise is not as large as 90mA. But just seeing a 50% variation if Vf at the same current, and a 4x variation in lumens at the same current, makes me think the LEDs are terribly inconsistent, or you have some sort of a test setup issue causing the variation.
Not saying this to be critical, but my observations. Thanks for running the tests, I know it takes a decent amount of time and resources to do something like this.
—
PocketSammich wrote: I don’t need this, but I want it. Please sign me up.
Sbslider, that’s not actually two separate 5600K emitters. djozz plotted the lumen output as a function of the current of a single emitter as the dark blue line, and the forward voltage as a function of current for the same emitter as the light blue line.
So it’s not a test of consistency between emitters, although the result is consistent with a test I did separately.
Sbslider, that’s not actually two separate 5600K emitters. djozz plotted the lumen output as a function of the current of a single emitter as the dark blue line, and the forward voltage as a function of current for the same emitter as the light blue line.
So it’s not a test of consistency between emitters, although the result is consistent with a test I did separately.
Hope that makes sense.
Guess I should have read the legend . . .
thanks for the clarification.
—
PocketSammich wrote: I don’t need this, but I want it. Please sign me up.
I’m pretty sure that Sofirn does not do HA III coating, let go on a 6 dollar light. I guess that their silver flashlights are anodised but not to HA III.
Convoy’s have a nice clear coating but I know that Simon is keen on good coatings. But still I doubt it is HA III
So, at 3x rated max current, it still gave ~63lm/w efficiency.
Now I KNOW I need a source for a couple hundred of each tint!
Dang, you have that much lights to mod?
Nah, I want the bare LEDs for a multi-emitter light! I’m thinking a DIY photographic ring light with tint mixing. Or maybe a nice High CRI light for my house.
EDIT: I keep saying tint. What I mean is CCT or color temp.
—
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
There was some talk about getting “extra” LEDs several posts back. Is that even remotely a possibility? I’m thinking of doing a DIY photographic ring light, with tint mixing. I would like to buy maybe 100 of each tint, or even more, but I can’t afford 1000 at their price! Not saying it isn’t worth the price. I’m 100% certain it is worth every penny. I just don’t have that much money.
There have been several group buys in the past, but none planned at the moment that I know of.
I wonder if the LED’s are something Richard at Mountain Electronics would interested in stocking. They’re good for tinkering since 5mm LED’s are easy to work with.
I think somebody a few pages upthread found an Australian vendor that has them. You might see if you can find the post.
I’m pretty sure that Sofirn does not do HA III coating, let go on a 6 dollar light. I guess that their silver flashlights are anodised but not to HA III.
Convoy’s have a nice clear coating but I know that Simon is keen on good coatings. But still I doubt it is HA III
I have never seen a real (good) HA3 coating on a Chinese light except for maybe Zebralight. At the very least they are not as good as they could be. The best coatings I have seen/felt are from HDS and Surefire (and I have no problem criticizing their lights for lots of other reasons). Maybe also Lupine. This is entirely subjective though. My current Armytek definitely gets way more scratches from keys than my HDS ever did.
Today when I arrived home I picked one of my 2 AAA flashlights, the Nitefox K3 and its diffuser.
I don’t know if this is relevant, important, doable, interesting, or not, but given the (future) specs of the flashlight being discussed here, would it be “nice” to have a diffuser for it? Again, I don’t know how “important, etc…” it would be, and also if it would add anything “interesting”, but would it be nice to propose a diffuser for this light? Just an idea… :ARROW-RIGHT:
I’m pretty sure that Sofirn does not do HA III coating, let go on a 6 dollar light. I guess that their silver flashlights are anodised but not to HA III.
Convoy’s have a nice clear coating but I know that Simon is keen on good coatings. But still I doubt it is HA III
I have never seen a real (good) HA3 coating on a Chinese light except for maybe Zebralight. At the very least they are not as good as they could be. The best coatings I have seen/felt are from HDS and Surefire (and I have no problem criticizing their lights for lots of other reasons). Maybe also Lupine. This is entirely subjective though. My current Armytek definitely gets way more scratches from keys than my HDS ever did.
This is a keychain light, floody, and only about 8-10 lumen. Diffuser is really not needed but if Sofirn would make it for those who wants it as an optional accessory, that would be great.
I never had a diffuser on my E01 that I am carrying. Wouldn’t it easily come off in your pants due to putting the key in and pulling it out?
This is a keychain light, floody, and only about 8-10 lumen. Diffuser is really not needed but if Sofirn would make it for those who wants it as an optional accessory, that would be great.
I never had a diffuser on my E01 that I am carrying. Wouldn’t it easily come off in your pants due to putting the key in and pulling it out?
+1 The only way I see a diffuser being useful on a light of such small output, is if it had TK’s candle mode installed and you wanted to use it while in a concert.
—
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
This is a keychain light, floody, and only about 8-10 lumen. Diffuser is really not needed but if Sofirn would make it for those who wants it as an optional accessory, that would be great.
I never had a diffuser on my E01 that I am carrying. Wouldn’t it easily come off in your pants due to putting the key in and pulling it out?
DavidEF wrote:
[…] +1 The only way I see a diffuser being useful on a light of such small output, is if it had TK’s candle mode installed and you wanted to use it while in a concert.
Hum, the perspective I thought was more on an indoor environment. With the warmest tint, I thought it could be of some use! But, as I don’t know how that will end to be in terms of luminosity and beam, I don’t know if the idea was good or not! Hence my suggestion
Thanks for your inputs, though
BTW, David, on concerts I like the stroooooooobes for better headbanging
I don’t know if this is relevant, important, doable, interesting, or not, but given the (future) specs of the flashlight being discussed here, would it be “nice” to have a diffuser for it? Again, I don’t know how “important, etc…” it would be, and also if it would add anything “interesting”, but would it be nice to propose a diffuser for this light? Just an idea… :ARROW-RIGHT:
It’s a good idea. An easy diy option is the cap from a tube of chapstick, which will fit on many AAA lights.
Results of the Yuji high CRI 5mm led tests.
While doing the output/current tests of the 3200K and 5600K version it became very clear that these are different leds, not just a different phosfor. Then I took a closer look and the build appeared slightly different too. At first that made no sense to me, the difference should only be the phosfor. But then I remembered that the 3200K and 5600K batch were purchased with 2 years in between, 3200K in January 2015, 5600K in May 2017, so in between Yuji had changed the design (for the better, as seen in the test) So most likely the 3200K leds in the new Sofirn behave like the 5600K led in this test, apart from the tint.
For the test I thought it would be fair not to cool the leds as well as possible but simply solder them on a common FR4 board, so the heatsinking would not be too different from how the led is mounted inside the flashlight.
Here are the output/current tests:
Directly after the test the leds and led wires felt luke-warm to my lips, nowhere near hot.
This chart already shows that the chosen 25mA is a very conservative current, at 50% or less of the maximum possible output and 30% of maximum current, while most of my flashlight builds are 80% of max output or more.
But to get a hint at longterm stability I soldered the two leds in series and did a 24-hour runtime test at 50mA (so double what the leds will get in the flashlight). Here are some voltage and output numbers of the combined leds in series:
0 hrs 6.43V 29.9lm
5 min 6.37V 28.2lm
30min 6.35V 27.6lm
2 hrs 6.37V 28.0lm
3.5hr 6.38V 28.0lm
10hrs 6.39V 28.3lm
16hrs 6.35V 27.5lm
24hrs 6.38V 27.7lm
So, nothing exciting is happening here, the leds are fine and show no signs of fading. So unless led death is a sudden event without performance warning, also 50mA is a fine current for these leds.
AFAIC, the suggested 25mA drive current for the flashlight is a nice careful current.
link to djozz tests
Thanks all for all the input about things I do not know much about, like jon_slider and Noir for info about potting and Noir for driver info. Especially the driver info I will communicate literally to Barry because it is stuff I do not understand myself and hopefully the Sofirn engineers do understand it.
link to djozz tests
Djozz, thanks for sharing your test. Useful data like this is great to see, especially seeing the improvement both in output and Vf.
I’m also glad to see your test has a good match to a similar test I did with a 3200K purchased in the last 6 months. I can’t measure lumens, but I did see intensity peak at 90mA, with Vf around 3.2V. Here’s my results (along with another user’s CRI data further down the thread):
http://candlepowerforums.com/vb/showthread.php?444187-Yuji-BC-5mm-LED-Stress-Test-Graph-and-Images
Even better, you have lumen maintenance results that I have not attempted. It looks like there was a small drop in output over the first 30 minutes as they warm up, and then fairly stable for 24 hours.
That supports a separate plan I have for a little personal project driving 9 of them in parallel at 350mA – as long as I don’t get too much current hogging due to variation in Vf or voltage drop in the wiring.
I hardly ever visit CPF so I had not seen your nice test before, very nice that my result matches yours, and I see that the assumption is correct that Yuji changed to a new make of led between 2015 and 2017.
link to djozz tests
djozz your test is nice, but it doesn’t show how hot the emitter gets on the inside and how its life expectancy is reduced. I would not overdrive them.
Project Excalibur - Next Generation LED Thrower (UPDATE 2018-01-15: 1.7Mcd)
Portable Thrower Comparison
No, it does not show that, that is why I called the 50mA test just a hint at longterm stability. Sofirn is going to use 25mA for the AAA twisty which is within the specifications for this led (30mA maximum continuous current).
link to djozz tests
So, at 3x rated max current, it still gave ~63lm/w efficiency.
Now I KNOW I need a source for a couple hundred of each tint!
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
Interested in:
1 3200K
1 5600K
Interested in a neutral white one
Interested in:
1 3200K
1 5600K
“History doesn’t repeat itself, but it sometimes rhymes,” Mark Twain
…
After the Apocalypse there will be only 2 things left alive, Cockroaches and Keith Richards
I don’t know much about flashlight LEDs, but it seems like you have a HUGE variation in the performance of the two 5600K LEDs. I know the planned drive current is around 25mA, and the variation there percentage wise is not as large as 90mA. But just seeing a 50% variation if Vf at the same current, and a 4x variation in lumens at the same current, makes me think the LEDs are terribly inconsistent, or you have some sort of a test setup issue causing the variation.
Not saying this to be critical, but my observations. Thanks for running the tests, I know it takes a decent amount of time and resources to do something like this.
PocketSammich wrote: I don’t need this, but I want it. Please sign me up.
Sbslider, that’s not actually two separate 5600K emitters. djozz plotted the lumen output as a function of the current of a single emitter as the dark blue line, and the forward voltage as a function of current for the same emitter as the light blue line.
So it’s not a test of consistency between emitters, although the result is consistent with a test I did separately.
Hope that makes sense.
thanks for the clarification.
PocketSammich wrote: I don’t need this, but I want it. Please sign me up.
Interested in:
1 3200K
1 5600K
Sign me up for 2× 3200K please.
EDIT: can natural HA III colour be an option?
I’m pretty sure that Sofirn does not do HA III coating, let go on a 6 dollar light. I guess that their silver flashlights are anodised but not to HA III.
Convoy’s have a nice clear coating but I know that Simon is keen on good coatings. But still I doubt it is HA III
link to djozz tests
interested in 3 of each tint probably
Dang, you have that much lights to mod?
I’m in for couple 56K.
Nah, I want the bare LEDs for a multi-emitter light! I’m thinking a DIY photographic ring light with tint mixing. Or maybe a nice High CRI light for my house.
EDIT: I keep saying tint. What I mean is CCT or color temp.
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
There have been several group buys in the past, but none planned at the moment that I know of.
I wonder if the LED’s are something Richard at Mountain Electronics would interested in stocking. They’re good for tinkering since 5mm LED’s are easy to work with.
I think somebody a few pages upthread found an Australian vendor that has them. You might see if you can find the post.
They’re not ring lights, but you might also take a look at the Viltrox panels, like the VL-162T and L116T mentioned here:
https://www.reddit.com/r/flashlight/comments/7fal9w/nld_viltrox_vl162t/
I have never seen a real (good) HA3 coating on a Chinese light except for maybe Zebralight. At the very least they are not as good as they could be. The best coatings I have seen/felt are from HDS and Surefire (and I have no problem criticizing their lights for lots of other reasons). Maybe also Lupine. This is entirely subjective though. My current Armytek definitely gets way more scratches from keys than my HDS ever did.
Project Excalibur - Next Generation LED Thrower (UPDATE 2018-01-15: 1.7Mcd)
Portable Thrower Comparison
Today when I arrived home I picked one of my 2 AAA flashlights, the Nitefox K3 and its diffuser.
I don’t know if this is relevant, important, doable, interesting, or not, but given the (future) specs of the flashlight being discussed here, would it be “nice” to have a diffuser for it? Again, I don’t know how “important, etc…” it would be, and also if it would add anything “interesting”, but would it be nice to propose a diffuser for this light? Just an idea… :ARROW-RIGHT:
MY REVIEWS THREAD /// My Flashlight Collection ///
Mods: 1 / 2 // TIR: 1 / 2 // Others: Biscotti 3 + 1*7135 / Triple TIR w/ XP-G2 /// My Review's Blog (PT) /// OL Contest 2019 /// OL Contest 2020 /// GIVEAWAYs: 1 / 2
Maybe you never saw the BLF EagleEye X6-SE with HAIII ano?
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
Interested in
1 × 3200K
1 × 5600K
Don’t mistake my kindness for weakness.
I am kind to everyone, but when someone is unkind to me, weak is not what you are going to remember about me.
This is a keychain light, floody, and only about 8-10 lumen. Diffuser is really not needed but if Sofirn would make it for those who wants it as an optional accessory, that would be great.
I never had a diffuser on my E01 that I am carrying. Wouldn’t it easily come off in your pants due to putting the key in and pulling it out?
+1 The only way I see a diffuser being useful on a light of such small output, is if it had TK’s candle mode installed and you wanted to use it while in a concert.
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
Hum, the perspective I thought was more on an indoor environment. With the warmest tint, I thought it could be of some use! But, as I don’t know how that will end to be in terms of luminosity and beam, I don’t know if the idea was good or not! Hence my suggestion
Thanks for your inputs, though
BTW, David, on concerts I like the stroooooooobes for better headbanging
MY REVIEWS THREAD /// My Flashlight Collection ///
Mods: 1 / 2 // TIR: 1 / 2 // Others: Biscotti 3 + 1*7135 / Triple TIR w/ XP-G2 /// My Review's Blog (PT) /// OL Contest 2019 /// OL Contest 2020 /// GIVEAWAYs: 1 / 2
Put me down for 2 × 3200K and 2 × 5600K
It’s a good idea. An easy diy option is the cap from a tube of chapstick, which will fit on many AAA lights.
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