[1900k edition is in!] WTS: 1900k-5800k 5mm LED 95+ CRI

Nice! I bought some!

FWIW,

some time ago I’ve shown a 1:3 mix of the 5800K and 2300K resp. LEDs. Now that I got that Opple Lightmaster, I measured:

Payment sent for a pack of 50 1900K leds tracked to Taiwan

That is nicely under the BBL, Unheard, does the Opple give the duv value too?

No, I need to convert x,y by hand:

gives –0.0051

Interesting, but not very natural, I would not want it for an EDC light.

Here's the CRI test results from Djozz for 19K-C (1900k).

Cool! My package has hit US customs the last time I checked.

Awesome!!! A true candlelight warm hi CRI!
I’ve been using the 2400K for such, but will HAVE to get some of these now.
Will there be any output/current/voltage data on these?
Thanks again for finding and offering these gems to the community.

You can look at the table in the OP (unless you want a graph data, which I don't have right now). I have updated table with the new emitter since it's introduction.

I would be interested. Should I expect that the lumen output would be even higher than the 3200K-EX?

If you're interested, you can put your name in here (with size & quantity):

https://budgetlightforum.com/t/-/66585

I'm keeping the record so I can pull the trigger once it hits the threshold. For now, the interest is only ~15% of the set threshold, so I need a lot more interest in the project so I don't end up losing a lot of money.

Done

I realize this is about upgrading the stock LED in the C01 to the EX LED, but can someone give more details? Thanks…

I'm going to repost Djozz's modding here. It's about the 22 Ohm resistor on the board.

In his case, he did the opposite by instead of bridging the resistor, he opted to replace the resistor with larger value of 220 Ohm to reduce the input into sub-lumen and extend the battery life.

https://budgetlightforum.com/t/-/51879/3184

In his picture, you can see the "221" resistor (220 Ohm) on the left. In the stock boards, you will see "220" (22 Ohm) instead. That's the resistor you need to bypass to increase the drive current.

Also, I have an old Black Diamond headlamp that use to have an incandescent bulb that I am thinking of modding with 14 of the 32K-C-EXs wired in parallel. It is setup for three AAs, but I can easily modify it to only use two AAs instead (and would use NiMH batteries). Anyone see an issue direct driving all those LEDs with that setup? I have actually already had 14 LEDs in it a long time ago and just always used three partially depleted alkaline cells to keep from over-driving the LEDs too much. From old emails I see the ordered the LEDs in 2003 from some guy named Brian Lam; they were suppose to be 8000mcd white LEDs.

Looking closer at the chart in the original post of this thread, it appears I could actually use the 34K-A ones and get 22lm of output (per LED) driving them with 120mA which is only a bit lower than the 27lm for the EX model. Is that correct or am I missing something?

@rngwn
Thanks for the pic and explanation as well as the link to that other thread.

Well, the problem with driving the 34K-A at 120ma is that you will kill the LED rather quickly. I asked iamlucky13 to abuse my emitters a few years back, and this post is what he reported:

https://budgetlightforum.com/t/-/58510/382

As you can see, it permanently degraded the 3400k emitter (34K-A) within a span of days when being driven at 125mA. 2300k emitters could handle a bit more, but still...

As a rule of thumb, you should never drive the LED past it's peak output curve (34K-A peaked at 110mA). Otherwise, you will destroy the emitters in a hurry.

To get a reasonable lifespan, you should limit the current to 50-80% of that peak (90mA for standard model [edit: for 34K-A, can't vouch for other models], 120mA for EX version). So, you will realistically get 21lm from the standard model vs 27lm EX models. That's about 30% difference, so take it what you will.

Thanks again rngwn! I suspected that might be the case. :slight_smile: It is good to know I can safely drive the 34K-A with 90mA and get about 20lm out of each one. That lower current will equate to a longer run time which is a benefit — so they might actually work better for me then the EX model really. Going with a standard model would also allow be more choice of color temp too. I’ll have to think about it some more…

After looking further at the lumens vs. current vs. voltage graph (in the initial post), I realized that the 34K-A needs a bit more voltage than the 32K-C-EX so I don’t think they would run very bright with just two AA NiMHs. So I think I am going to go with three AA batteries and a DC-DC regulator to control the power. Finding a DC-DC small enough to fit in the head of the flashlight was an initial concern, but I think I can get one in there with my projected setup. Is there a graph like the aforementioned one that also includes rngwn’s other standard LEDS (besides the 34K-A)?

I had no idea that the Nichia GS was rated as high as 70ma. Does it get warm at that level? I’m actually not worried about going that high. I’d just love to have a 5 lumen, 5mm coin light with decent tint and runtime.