I realize this is about upgrading the stock LED in the C01 to the EX LED, but can someone give more details? Thanksā¦
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?
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. 
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 ā 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. Iāll have to think about it some moreā¦
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 donāt 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 rngwnās 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? Iām actually not worried about going that high. Iād just love to have a 5 lumen, 5mm coin light with decent tint and runtime.
Hello,
This just came out of the blue, but it seems like the company that makes 23k-AB, 34k-A, 58k-A (2300k, 3400k, 5800k) has just gone out of business. The sales rep did not respond to my inquiries, and the company's minisite has seemingly gone missing from the marketplace.
For 23k-AB and 34k-A, I only have a few left, so I'm afraid that this will be your (lucky few's) last chance ever to get your hands on these.
23k-AB and 34k-A is now down to LAST pack each. I will not be able to restock them in the foreseeable future (if ever).
Do not send payment before I confirm it, if your order includes either of these. First come first served.
This is sooo sad. If you still have the last packs, I will claim both of them. I have 100 of each in my stock already but ā¦ they will eventually run out.
I hope youāll find alternatives.
Let me know, Iāll PM
Bummer, I had just talked myself into buying both.
rngwn,
If you find any more packs laying (or even partial packs) around, please me know via PM.
A big thanks rngwn for setting me up with the scraps he had left!
Thatās unfortunate news. Sofirn C01 is using those leds. Hopefully one of the other companies could fill in the void. Somewhere between 2700k - 3500k.
I do have backup companies to order from. The biggest problem is that I cannot get them as cheaply as Sophia's. In fact, I'd rather be making 0.5w models which delivers more output and could fit more hosts because the BOM gap between the standard models and those EX models isn't all that big anymore.
I do happen to have a high-CRI 3mm prototypes laying around in 3200k and 4000k, so I might as well list them here for $8/50pcs as well.
The 1900K 5mm LEDs are awesome!
I swapped out 6 cold white emitters in a simple flashlight, transforming it from a well-meaning gift I didnāt have a use for into a fantastic night-time companion. ePacket delivery took 21 days to my US address, which Iām happy with given expected holiday shipping delays.
All photos are locked to ISO 55, white balance 4500K on a Pixel 4 XL.
Iām running the LEDs at around 10 mA via (((4.0ā2.7)Ć·20)Ć1000)Ć·6. (6 LEDs in parallel, 20 Ohm resistor, roughly 4 volts from lightly used 3Ć AAA alkaline in series, ignoring internal resistance. Iāll switch to NiMH.)
Click/tap photos for larger view.
Before - 6Ć stock cold white LEDs:
(The flashlight is already partially disassembled, making the side spill more visible.)
After - 6Ć RWN05-19K-C:
In case itās useful for anyone else, hereās a tint comparison against a D4SV2 with OSRAM W2 and a KR4 with Nichia E21A 2700K and non-floody optic.
Tint comparison - OSRAM W2, E21A 2700K, RWN05-19K-C:
(The host flashlight body is very basic. There isnāt a dedicated optic, just a plastic cover. Iām impressed by how well this worked.)
1 Thank
Good work! Enjoy the candle-like color.
These 5mm LEDās basically are their own optic and are not typically used with an external optic. I believe both the size of the cavity the LED sits in and the height and curvature of the dome affect the beam profile of a 5mm LED.
Update: The postal service has raised the cost of e-Packet to U.S. once again. From March 1, 2022, the ePacket shipping cost to U.S. will be $11. The shipping cost to other countries remains the same until further notice.
Until then, the ePacket shipping cost to the U.S. remains the same $10.