Feasibility study: Luminus SST-90-R Flashlight (620nm red light)

Hello everyone,

Since I am interested into high-powered monochromatic flashlights the Luminus SST-90-R came to my attention. Until now I have tried out different LEDs like XP-E, XP-E2 and Epileds 5050 but none of them are good in terms of output, heat excess and efficiency. Now, with the SST-90-R there's a chance to achieve real brightness with red light as it yields up to 1,500 lumens at 9A current, i.e. with a 4-emitter array you could easily get 5,000 - 7,000 lumens of red light.

https://download.luminus.com/datasheets/Luminus_SST-90_Datasheet.pdf

With the intention to use this LED in a flashlight host there seem to be quite some obstacles to overcome i.a.w. the datasheet.

  • Unlike common LEDs this one has a footprint of 110x100, i.e. there is the necessity to invent a new reflector design or adapt an existing one.
  • The LED board would also need to be redesigned to reflow this LED appropriately.
  • It would also require a new driver to run a multi-emitter setup of let's say 4 pcs in serial connection (4S = 12V) to apply 9 to 13.5A to all 4 LEDs. With a parellel design it would take insane 50A otherwise.
  • Depending on the battery carrier configuration (2s or 4s) it needs to be clarified whether it can be run with a buck or boost driver.

Has anyone an idea if something like this can be done or how realistic it could be to convince a manufacturer like Acebeam to develop such a flashlight? So far, the Acebeam X80-CRI is the only flashlight with substantial red light but it's a floodlight with only little range.

Where would you use the red light for?

You can put it into a flashlight, people have done this before. It is not as large as you wrote, you added a zero (It’s 10mm x 11mm). The LED can be soldered onto the Noctigon MT-G2 pcbs. You can use a buck driver to drive it at the correct current.

The LED is very outdated though, there are better options in terms of efficiency (Cree XP-E2 red, Epileds 5050 Xm-L2 Style red led, some projection LEDs from Osram).

Don’t forget the Olson SSL-80 which is THE MOST efficient LED in terms of usable light focused by the optical system.

Not the most efficient red LED, the most efficient LED period…

No, not in all cases. It’s only more efficient when combined with an aspheric lens. If you combine it with a reflector, less light will actually hit the reflector. This means there will be less light in corona and hotspot, but more in the spill.

Actually, just for fun in my case. I know there are some rare scenarios where red light is mandatory or helpful (hunting, lightpainting, maintaining night vision) but none of these seriously apply to me.

Thanks. Yes, you are right, it's 10mm x 11mm. Unfortunately, the LEDs you mentioned do not have the necessary output I am looking for. With 4 XP-E2 you might achieve 1,200lm but never 5,000 to 7,000 lumens. What I am looking for is a flashlight like the Q8 or Acebeam's X45 with the abilitiy to have a bit of throw and not only a flood light like the X80-CRI. Furthermore, XP-E2 and Epileds 5050 are not safe for usage with FET-drivers. They will easily burn up if driven too hard.

https://www.mouser.de/ProductDetail/LED-Engin/LZ4-00R108-0000?qs=sGAEpiMZZMu4Prknbu83y4xInUYYMTeMIsOLPjBvmxo%3D

if you got boost driver this might be also worth a look, maybe not that top lumens

the SST-90 is only available at BJ flux, if there would be BK this would be pretty much a very efficient LED

SST-90-R-F11-HJ102 is the max. order code that may also contain higher flux bins but then you would need to selct LEDs

Yes yes, sorry for any confusion… To me “optic system” means TIR or aspleric lens, not reflector based, but I see how that statement could be misconstrued.

Why do you want to use such expensive LEDs with a cheap FET driver? I wouldn’t take that risk. Here is a buck driver that can do 11A for each LED. You just need enough batteries in series.

The SST-90 is also not safe with DD driver the firward voltage is too low
What you need is a 4S battery carrier and 4S buck driver so you can use the low Vf to get efficiency up
I got MF01 dual buck with up to 13A regulated current for 4S

SST-90s could fit Cree MT-G boards:


There are Noctigon 16 and 20 mm DTP copper boards for MT-G.
.

If you are into monochromatic LEDs have a look at the 2018 OSRAM OSTAR Projection Compact LE x Q8WP (not Q9).
B 459 nm blue, T 530 nm true green, CG 500…600 nm converted green, A 617 nm “amber” (red-orange) and R 625 nm red.
Not as powerful as the SST-90 but max current is still up to 5 A and unlike the Luminus SFT-20 (2 pads asymmetric) they seem to have 3535 footprint.

I have several Luminus Platlight PT-54, I love them :smiley:

Don’t even need to do that… you can order these already on a star from the factory, it is SSR-90. They even have a version with a flat window SBR-90 but with less lumen rating; but probably better for “throw.”

Many Luminus LEDs are available with these standard aluminium star boards. They look like the cheap non-DTP boards but they are listed in the data sheets so they should be okay up to official max current.

But that is not why we are here, right?

Was addressing one concern in the OP:

I was wondering why the OP talked about a “board”, then found it in the data sheet. So I guess he knows about the star boards and wants/needs something else.

There are two reasons to reflow: 20 mm diameter will not fit into the flashlight (more of my flashlights can fit 17 mm than 20 mm boards) or to improve the heat transfer of the standard aluminium board.

Actually and initially, I was not looking for a single emitter option but for a good multi-emitter light like Acebeam's X45 or something like HaikeLite's MT09R. The original LED boards would not work with the SST-90-R, that's why I thought these may need to be redesigned. Anyway, if there are recommendations or ideas how to run this LED in a smaller, one-cell host like a Convoy C8 or L2 I'd be more than happy to know about it. :-) I doubt this can be done without huge efforts in adapting the reflector and driver.

Finding a suitable driver is easy. Use a linear driver, they are compact. The LD4 led4power is perfect for this.

Or, just get one Luminus PT-121RA… you just need to figure out how to give it 36A :+1: