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Hi, rngwn.
Do you plan on selling less powerful high cri COBs ?
Not yet, at least not in the same form factor. The major reason is that by simply sourcing 100w (the most powerful) variant, it gives buyer choices to run it at lower power settings without having to deal with too many product lineups (which I cannot financially deal with as of now). Also, once overheads (such as shipping costs) are taken into the equation, the lesser variants don’t get that much cheaper.
Aside from some tint shifts (that is can potentially be a negative thing), underdriving a more powerful LEDs will result in better efficiency and longer lifespan. As far as voltages are concerned, all variants in this form factor (except the AC ones) are to be run at the same voltage. All you need to do is to pair it with a less powerful drivers or just feed it with less current.
I assume you mean lower voltage? How much voltage do you have to work with? Is it batteries or wall power?
The idea is to improve the lightening in my flat (currently ~300 LED Watt, mainly ceiling chandeliers)
I’d better opt for 5-20w COBs and maybe some led chips in 5050/5630/5730/etc size with 0.5w-3w.
100W cob is just over the top for this task imo.
“5mm LED 95+ CRI” from other rngwn’s topic does not suit as well :).
I was looking through alibaba website but finding a reliable supplier with fair HI-CRI LEDs might be a bit tricky…
I have also ordered a pack of 90+cri Samsung LH351D some time ago (thx BLF for Samsung LH351D 5000k 90CRI LED $0.74 with Free Overnight Shipping) but use it for “lazy” flashlight mods only.
For lighting my house I use these LED bulbs
I measured the CRI at 93. But be careful, they are USA voltage.
Yes, I saw your feedback here - [Review] 5700K CRI95+ COBs from user rngwn - #9 by Joshk.
But as you’ve already said they are in the USA and apply for USA voltage.
I need to find either led bulbs for 220V or suitable LED chips, preferably directly from China ( e.g. aliexpress/alibaba/taobao )
IIRC, there is an Aliexpress store named MARSWALLED who sells High CRI strips.
All you need is 220v to 12v driver and a proper tubing.
If you want to use these COBs as 9w lighting, you sure can.
From my review you linked, I have tested/operated them like that.
—0.25A 26.5v—
CCT: 6191
Duv: 0.0008
CRI: 97.3
TLCI: 99
—0.50A 27.02v—
CCT: 6156
Duv: 0.0006
CRI: 97.7
TLCI: 99
Need:
2x3500
2x5700
Europe tracked shipping
PM coming
Do you still have these? I’d like two 5700k.
Yes.
So question: what optics/diffusers would you recommend for such a light?
I still haven’t found any real uses for them, so I want to make some room lighting with it, some particularly bright portable room lighting 
For me, I put it in a floodlight and then put a frosting sticker on the glass panel to diffuse the light. Not the perfect solution, but it's good and practical enough for me.
I see.
I personally want to make something like a studio light, so I guess I’m going to have to make a chonky heatsink and find some good actual optics.
Did you ever do this? Putting together the same. Bought two Thermalright Assassin Spirit 120 heatsinks for $24/ea, but still figure out which COB & Optics.
It’s either:
- the one in this thread, 22mm, 100w, ?? lumen, ~95ish CRI, $12
- Bridgelux Vero SE 29 Gen 7, 29.2mm, 80W, 11k lumen, $28
- Luminus Devices CVM 27 AB00-F2-3, 26.5mm, 150W, 12.5k lumen, $48
Both other brands have a newer version that’s 20% more efficient, but I spent last few days searching and they’re not available anywhere unless buying in bulk.