I once received and fiddled with a C8S Sofirn buck driver (sense voltage: :facepalm: ≈0.23V), it worked but as usually happens with very high sense voltage drivers can't really say great things of it from a modder's viewpoint, imho burns too much power in the sense resistor and this means lesser efficiency and small room for overcurrent purposes.
What where the Sofirn managers thinking when planning the C01S? They probably cheapened to the brim in the driver for maximum cost savings, and the price paid is lack. It strictly is a boost driver, blows up with li-ion cells (no multi-chemistry). Its sense voltage, at ≈95mV, could be better, and also detrimentally contributes to a high minimum Vin to Vout difference.
Well, hope they can do some optimization to the driver for it to end up working. I wouldn't really mind if it means the low mode ends up being slightly more bright than it should, just slightly of course. Hope they also rework the current sense thing to reduce the Vin to Vout difference, and as a side effect we get improved driving current for red emitters.
The color E17A is a 3V LED due to being phosphor converted from blue.
However, it probably won’t appear as deep of a shade of red as a photo red, nor be as efficient as standard red.
Additionally, it was already mentioned Nichia’s can be hard to source in small to medium quantities, and as reported by Clemence, these chip scale packages are more difficult to solder to a board. Perhaps they could buy enough from Clemence, but almost certainly at a higher price than buying straight from a distributor, especially if Sofirn normally has their LED’s flowed onto PCB’s by a shop with pick and place equipment and other aids.
Sofirn told me a prototype will be ready soon. According to their engineering dept. they will not be able to reach 470mA but they will try to get as close as possible.
GrrreatLux-Perpetua, looks like they are going to make it work. They won't be able to get to ≈470mA? I think that means they could fit an R22 for ≈430mA. So, there will be improvement. :THUMBS-UP:
Currently, Sofirn‘s engineering is working on a prototype, maybe even a whole new driver. Once that has happened I plan to discuss the result of the UI poll with them to see if we keep on using the „high-low“ UI or move on to a more advanced UI (at higher costs). Eventually, Sofirn is going to launch the manufacturing process. Maybe they will only offer deep red or both red and deep red, depending on their sales forecast and supply in components.
I don’t have any confirmed updates yet but I‘ll keep you updated.
Thanks so much for the update and the whole project Lux, sounds pretty good! I think this is going to be a really unique little light ideal for so many tasks.
My lack of knowledge will really show here, but here goes: is the deep red just less bright or am I missing something? Are there any beam shots of these two leds? I don’t care so much which are used AFAIK but I’m just curious.
Many thanks once again for all the hard work and the great idea!
According to the datasheet Amber emitters drop in output with increased temperature in a very steep way, i.e. their output at 85°C is just ⅓ of what they do at 25°C.