I finally got around to ordering 100 of these unique little 3400K LEDs today!!! Looking forward to working with them on some projects.
Been out of the making and modding lights for a while… but with 2 (…and now looking at 3) PG&E power outages here lately I’ve renewed inspiration to make more custom battery powered indoor lamps and lights.
Lights that run for hours, soft lighting that is warm and comfortable. That’s what is needed when the power is out for many hours! These little warm high CRI wonders have inspired me.
I got a sample of 10 of his high CRI 5600K leds from rngwn in this week and I did some testing.
First a beamshot from 20cm distance from the wall:
Actually this shot looks nicer as in reality, the beam is indeed really smooth but there is a slight tint change at the very edge but it is nothing serious, at least not so bad as rngwn’s own beamshot in this thread.
So the tint is really really good and does not change much at different currents.
The light output. I made no graph (not enough time) but a video. You see the led shining at a luxmeter that I placed at a precise distance so that the luxmeter reading is quite exact 10 times the output in lumen. So a reading of 93 corresponds to 9.3 lumen total output. The voltage and current can be read from the USB power supply. I checked, they are not greatly off from reality.
So, like the 3400K led, it maxes out at about 120mA (25 lumen), but above 80mA (22 lumen) there is not very much gain. This is a very nice performance, at a bit but not much better than the Yuji 5600K led.
As discussed via PM also, I expect a good market for high CRI 3mm leds, especially at warmer tints. Of course over here we like them anyway because we like all leds, but in model building (trains!), perhaps a bigger hobby than flashlights worldwide, a lot of use is made of 0603 and 1205 leds, sold on ebay with two wires already attached because soldering them is too difficult for most, while the application of standard 3mm leds is more robust, way easier and often looking better. I have one time bought warm 3mm leds (was not easy to find) and the tint is quite disgustingly yellow-green, I would not like to light my preciously built railroad yard with those.
But I’m not a model builder and do not know one so perhaps someone else can confirm?
Thanks for that info led4power, I did not know that. The graph is very convincing, and overdriving 5mm leds makes it much worse. Not that lifetime matters greatly for what we hobbyists do here, my Nitecore Tube is used for 3 seconds once a day to look into the letterbox, but if we do serious builds for Nasa it does matter a lot.
I don’t have data for this particular LEDs, but a very old “fade test” data from CPF do suggest that a really well-made 5mm LEDs (radioshack’s) might happily last 50k hrs at 30ma.
For Nichia-tier LEDs, they would last ~5000 hrs at 30 ma (at L70 a.k.a. leds considered “failed” when the brightness drops below 70%)
The thread also mentioned that, LED lifespan increases 4x for every halved currents.
For these LEDs though (which is now known to be more efficient than Yuji’s and probably many standard 5mm LEDs), my educated guess would be at least ~4000 hrs at 30ma/ ~1000 hrs at 60ma L70. For occasional usage (i.e. 1 hours/day) that will take years until the degradation becomes apparent.
Got a notice from the post office in my mailbox yesterday
I have no idea why that time they droped a notice in the mailbox instead of the parcel like for the previous leds but i was lucky enough to be able to go there today (as i am usually working during opening hours) and take the parcel.
It looks like it was opened (customs ?) but everything is fine and i am happy with the leds :)