Project: SUNLIKE LT1 board (Option for 660nm Red)

We’re talking about 123 vs 153 mA/LED and the same total current. Efficacy improvements will give at most a few percent difference in output. Please note that most of efficacy improvements come from lower Vf rather than higher output. And here this improvement will be burned by 7135s anyway.
And in the datasheet I see a few percent difference between CCTs as well.
So I actually think it would act as an output equalizer.

This may be different if the LT1 driver has extra 7135s soldered (which I would recommend anyway).
EDIT: I see that 7*7135s per channel is the max. So efficiency improvements from having more pads would be quite small but still, they should improve the outputs balance.

This is what I said but LampMan (BelMOR) is adamant that the warm and cool emitters are the same brightness.

I expect the lower Vf than the LH351D and same current but higher light output will result in a cooler LT1 head/top part which is good since that’s where I notice most of the heat building when running my LT1 for extended periods of time with 7 amc7135s active.

SunLike LEDs have lower flux per wattage =(
It will not colder or brighter!

Id like to have at least one. Im not too picky and will likely settle on a popular combination of warm tints, once the group reaches a consensus. This is an interesting thread and I appreciate the R&D going into it.

1. I can do 18+18, it is all in this space
2. In future will be 3rd generation of SOL2835, it is much more brighter, but without violet
3. 660nm red have ~2.2v, not ~3v. It will work or no?

I see I’ve made an error. The LH351D has quite a low Vf when only driven at 600mA, about 2.8v while sunlike sol will have a Vf of ~3v at 150mA.

Assume all 7 7135s are active. That’s 2450 mA. Spread between 4 LH351D, that’s ~613mA. Spread between 16 sunlike 2835s is ~153 mA.

The figure I’ve seen thrown around for the LT1 with 7 7135s active is 840 Lumens. With sunlike (using the 64 lumens (5000k) at 150mA figure of the datasheet) the 16 emitters would produce 1024 lumens.

What is the lumens per emitter at 150mA? You say it’s identical for both 2700K and 5000k? This can’t be the case, can it? It seems like warm emitters are always more inefficient since the phosphor layer is thicker?

Correct for optical losses and higher temperature and you’re in the same ballpark but higher colour rendering and rosier.

BTW, I’ve notice a Refond “Sunfeel” mentioned in the catalogue with nicely looking spectrum but I fail to find any details.

Does anyone know more about them?

Yeah I’m not so sure about this project. The LT1 emitters are already pretty nice. The uneven glare is a bit annoying though.

When I proposed this I expected the benefits would be:

- Cooler head temperature

- Slightly brighter

- Better colour rendering

  • Smoother beam

It looks like the head temperature might not be cooler and the brightness increase wouldn’t be too substantial.

I’m not sure about the stock tint of the light. It might get a bit rosier? I’ve never thought of my LT1 as being green so it’s not an improvement imo


It will be about 600lm, not 1000. I mean with diffuser

BTW, I never use my LT1 above 2700K. I’d like to go warmer.

I’d like to have some cooler spectrum as well because I’d like the candle mode to vary CCT.
But for this to happen without going above 2700K I need some warmer LEDs. So unless I find something warmer it looks like 2700K at both channels would be the best choice for me…

I have a feeling that kapton converters from 7135 to E21A footprint would be a bad idea….but an entertaining one. :wink:

Warmer would be nice but it seems like we don’t have that option unless we find some different LEDs. My guess is that the diffuser should affect the LH351Ds and threes 2835 SOL emitters the same so brightness should be close if not higher with the sunlike emitters.

There was the LH351B in 2200K a while back, but it’s only 80 CRI.

I am interested in one.

2700K + 5000K is ok, but my ideal combination would probably be 2000K + 4000K.

Luminus Cube and Nichia E17A and E21A are available in some warmer color temperatures.

The Nichia are available through Eurekatronix, although that probably affects the cost.

The Luminus are available in a 2016 package (2.0mm x 1.6mm) and a 3030 package and may be easier to solder than the Nichias, which are chip scale package.

Add me for one. Thank you.

I think I will add this board to my site, customers will place an order after that I will give paypal from my business partner from China for payment. After 10+ payments I will order this flashlight. After I received (seems like 2-3 month) it I will finalized project and give it to the factory and after 1.5-2 month I will received 100-150pcbs and stencil

All done! Who need this pcb, just place order HERE and I will send paypal account for payment (with 5% fee)
It is possible to place order without registration, and there’s english language with button on the top

I think that will be better to add this to head comment

As you can see, way to speed up the project is send flashlight to me faster that Sofirn Official Store from aliexpress.

It will be 18+18 leds. I can soldering not all

And who want more warm spectrum, the 1 way to get it, it it is order 10-20k pcs 2835 leds in the factory or add 660nm. But red leds is 2.2v, so I need to test how it will work. Now I have spectrometer PG200N, so I can test ready pcbs with leds better that anyone without it

s. Do not spend my time anymore please. The only way why I do it, it is money! Yes, I like flashlights, but I can spend my time to creating head flashlight with 12w SunLike COB 36v LED (I still waiting leds from Seoul)

pps. 14.8$ (2.5+1.5+10.8) + 6$ (shipping for any order) + 5% paypal fee

Interested in one also.

Who need this pcb, just place order HERE and I will send paypal account for payment (with 5% fee)
It is possible to place order without registration, and there’s english language with button on the top

Hi Lampman, I made the order and asked for Paypal in a reply mail. Nice initiative, thanks Sunnysunsun and Lampman! :+1:

Check spam folder. Fu…ing gmail =(

paypal is: 50380707[d0g]
add paypal fee 5%
add mark: for Adam for BLF LT1 pcb order#