Luminus SST-40, a N4 BA bin tested

Mosfet resistance is irrelevant in case when linear driver operates in linear mode, in that case power dissipation in mosfet is (V_batt - V_led)*I_led.

So switching to other mosfet won't change a thing. Improving thermal path between mosfet top side and pill does help a lot, but it's not easy to make very good thermal path for deep pills/driver cavities. Example how to do it is S2+ thermal kit:

https://led4power.com/product/ld-a4-thermal-enhancement-kit-convoy-s2/

But again, this is not simple for many flashlights and cost is high, if LD-B4 can be used, it's the best method.

Your calculations are valid only when mosfet is in saturation mode - direct drive, where I^2*R loss it the only cause of heat generation.

Interesting results. I always thought dedoming this shifts the DUV higher which is the opposite of what you got. I wonder why the dedomed SST-40 NW in the Nightwatch NI40 is so horribly green +0.02x.

I might slice my FT03 SST-40 NW since there are now replacement LEDs available. I’ve never attempted a complete de-dome though and dont really want to get into doing that myself.

Have any one successfully dedomed SST40, Not slicing, i want to dedome it because i got a very cool white sst40 and i want it to shift color plus the throw

I just got 10 more SST-40 from KaiDomain. Do you want me to try one for you? What methods of de-dome do you have at your disposal? I would want to do what you could replicate, or it wouldn’t be much use to you. :innocent:

EDIT: Actually, just realized, I have some dead ones I burnt up. I’ll try those first! :smiley:

AFAIK Maxtoch seems to be the only one reliably chemically dedoming these. Seems it wasn’t easy when others tried?

Do you have any idea what chemical they might have used?

Nope dedoming these is tricky i think heat might work best. I killed 2 in petrol trying to dedome them. One worked with heat then got killed by a reflector sliding.
I just had one dedome its self now lol the silicone burnt up months after a sliced it. I don’t think its the LED fault it was out of the light for ages i just put the sliced SST40 back in my FT03 last night. Could of had dirt on it from storage as i had no issues with it till now and i used it sliced for over a few weeks. I had a XHP50.2 in my FT03 for the past few months.
Luckily i noticed the smoke and turned the light of i cleaned the dome with some alcohol and it seems to work still.

So I got my 5000K SST-40 LED’s recently… DD bin from Kaidomain and DA bin from Convoy. At low current the DD is a lot greener than the DA from Convoy. At medium current the DD is yellow and DA more white. At high currents the DD is white, where the DA almost has this slight magenta tint to it… I then went ahead and put a DA in my S2R Baton II with a beaded optic. And I can live with it, seriously. I will actually use this light now. And I have recently used my FW3A 219B SW40…. Obviously the color rendering is not good. But it’s an acceptable tint compared to any other SST-40 or XM-L2 in any of my Olights. I’m gonna order some more!

edsg - How did you kill them in petrol trying to de-dome them?

No idea. I think people only came to that conclusion cause of the macro photos of the LED make it clear it wasn’t sliced and diced like some of the Kaidomain ones or otherwise.

The Silicone stays on and takes the bonding wires with it. No matter how long you leave it.

I have 3 more that i sliced the performance difference isn’t to much between the two.

Gasoline has that nasty stank to it. Anyone ever try MEK or xylene?

I think some have. There have been discussions on BLF before about de-doming, and those two were brought up. I can’t remember what the results were. But I think I vaguely recall at least MEK was praised in those discussions.

I’ve heard of that happening with some emitters. I wonder if slicing most of the silicone off first, then soaking, might work. Have you tried that?

Do you mean the performance between sliced and full dome isn’t much difference or the performance of sliced versus fully de-domed?

That’d concern me, because with bare phosphor (and nekkid bond wires), any — I believe it’s called “schmutz” — could stick to it and burn when powered up.

At least if sliced, it could be wiped off.

This led gets my attention. I read through this thread and have more questions than answers.

My objective, in a nutshell, wearable on head worklight 400 lumen 4000 candela 12 deg Hotspot, 10 hours of cc, not green tint: I am interested in building more work headlamps that can get me 200 lpw for 10 hours, using 2s18650 and the buckpuck 700, 700 mA, with a dial dimmer. I use a 31mm,prefer 36mm aluminum smo, because I need a bare minimum 4000 lux at 1 meter. My last build was rain resistant, 2 series 18650 at rear of headband with buckpuck, the head pivoted (one build used thin copper pipe on aluminum with elastic) the led was an Cree XP-L v6 4000 Kelvin thermal epoxy mounted to a flat aluminum avid with finger spikes that epoxied to the aluminum reflector. This thermally epoxied to an old fashioned computer heatsink with thermally attached copper pipe for pivot. The open bezel design allows hyper cooling, with the aluminum reflector (thermally epoxied to pcb) as a huge part of the cooling. This allows a very low led junction temperature. I recall under 40C using mm probe and ir. At 700 mA I measured 373 lumens, over 4000 lux, which I could sustain 9.5 hours. My last build like these was in 2016. I have seen led technology marching backwards, chasing lumens and allowing spectrum filters for higher cri…… I might be interested in 80 cri, but I do not do photography, I only need to see subtle color differences, which even 65 cri metal halides do excellently—(cri+gai+luminance equals color, not just cri). I did attempt to build some 2x amc7135 lights but I really felt the drop in efficiency from 92% to 70% made the lights useless for my jobsite purpose. I really can’t do anything with a runtime much less than 10 hours.

From reading this thread, it looks like this led might bump up the runtime, while allowing the same throw/lux in a 31 mm at 700 mA. However, I am reading that the color will be unacceptable green at 300 to 700 mA. I am thinking that the sbt 70 would offer poor lux at the max allowed mah for a wearable worklight, which is 700 mA. (yes a 3s 1850, or 2s 21700, would allow 1 amp for near 10 hours, however, weight, charge time, and number of bays for 3 to 6 workers, gets messy).

The XP-L2 has lower forward voltage, but it has lower output at 700 mA, which is a big deal since 31 mm is available, while 36 is not. I do not like 40 mm Hotspot size. And at 31mm, my XP-L v6 barely got 4000 lux (minimum acceptable 2meter 1000 lux, for inspection). So, I am thinking the tradeoff of runtime for lower lux with 700 mA, not worth going that route.

I am also thinking that this led might not cut it either. (seriously, no advancement in leds in 4 years, other than wow factor and filtered spectrum to better cri, lower output? However, if output same, lower fV, longer runtime is a great plus since I am still struggling to get 4000 candela for 10 hours. But I hate green tint. I am happy with the 4000 Kelvin XP-L V6 70 cri, tint-although I would like to bump up to 80 cri, if I could without significant output loss. … I have purchased 3 95 cri lights in the last 3 years, including on fixed metal halide, but apart from the tint novelt, I am not really happy with loss in output tradeoff. I use them more as reference lights for my main work lights. )

Now, my un edited questions and notes that arose from reading this long thread, if anyone cares to read and answer:

1. What is the binning? (Flux : N4, Color : BA, Voltage: VK?)
2. Lpw at 1 or 2 watts? At 350 ma and 700 ma?
3. Gallery comparing color rendering v. Xpl v6 at same color temperature.
4. I take it that the fV is 15% lower than the xp-l v6. People are reporting it runs at same due heat as the xp-l v6 at same current. So, I am guessing a 15% longer runtime until the 7135 linear driver cuts out. This correct? Then, what about a 700 ma buckpuck, 92% efficienct buck driver v. A 70% efficient linear driver?
5. Having butchered every led I attempted to dedomed with razor and gasoline, I would rather buy a predomed sbt-40 that has been certified with a bin rating, above the xp-l v5.
6. I don’t understand why the sbt-90.2 is not smaller than the xp-l, 3030 v 3535, at a glance on spec sheet.
7. I don’t understand how the second generation of the sbt-90.2 fits in with the sbt-40: how much lower is the lux per watt as compared to the sbt-40 ; why am I not seeing the sbt-40 having a second generation like the sbt-90.2?
8. Are there any 2s18650 buck driver lights with ramping, which are headlamps?
9. Apart from the buckpuck with dimmer, are there any affordable buck drivers out there that target useful full workday runtime off 2 cells?
10. Do the dome defects and inconsistent suppliers make the led not worth ditching Cree? Is baking at a low temp for a while able to drive out humidity and avoid reflow bubbles?
11. Kaidomain.com, banggood, intl-outdoor, digikey? Aliexpress safe seller , RMM and IOS?, arrow? Mouser, mtnelectronis. Shenzhen Great Technology Co.,Ltd.?
12. Reflow onto same star as xpl? Lead solder paste Best, still in 2020?
13. Ring artifacts?
14. Any fixed lighting using the led?
15. What washer (thickness) could be used to dedomed, by protecting the die? Single edge, razor, scalpel, or beard razor, would work best? Detail Scissors? And, if I don’t get all of the dome off does it ruin the throw? Is it a really thin line between nicking the die and getting a dedomed led that is an improvement?… Toluene better than gas, xylene, lacquer thinner, acetone? (toluene is 5 minutes. Vinh stopped fully removing SST-40 domes, now he shaves them. He says it gives him the same throw, but better output.)
16. Best place to buy 36 mm or 31 mm smo reflectors? 26 mm, maybe for a dedomed version?
17. If I reflow myself, how to avoid creating bubbles, as is the case with most of these?
18. Tint lottery?
19. How badly does the tint shift during amp/mA change? It would suck if green if not slamming with pwm to highest current!! (twisted raven wrote: My SST-40 gives me a brilliant cool white with little green at max output, but at lower outputs on a non PWM driver, it gets rather green. My Quark 2AA-X does that. On turbo, it’s not too bad. On moonlight, greeeeeeeeeen. )
20. Voltage bin? VH, 2.5 VOLT, only good bin to beat the xp-l? (vj 2.7v, vk 2.9v,vl 3.1)
21. If a fet is a dd, with no resistor as mnt electronics claim, why would I pay $20 for a wiring bypass. Mnt can not be correct in what a fet driver is.
22. This is lower than the Cree v6 xpl version 1: Nw only 310 lm typical at 700 mA
170 lm/W typical at 700 ma. Why so much lower? VH and n5 bin in only 6500k?
23. Is this true?: “the die is larger than XP-L or XM-L2, so you either need large optics or a lot of power (or both) to get impressive throw numbers.” (The die is maybe slightly larger. I measured about 10% less throw than dedomed XPL V6 at the same current).
24. Has luxeon or Cree improved in the last 3 years. How about a xp-l v6 in 80 cri? (green tint in a useful =<.1C drive level makes the led useless, other than search and rescue and ocd pursuit).

Hank noctigons from hank, kd, VK from Ali, reflowed on noctigon, Kaidomain.com KD DTP copper MCPCB-s., or aluminum
21.04€ |10 stücke 100 PCS Luminus SST 40 10 watt LED 1 100 lm Kühles Weiß 7000 karat statt CREE XML2 XM L2 LED Licht Emitter Diode für taschenlampe|cool white|10w ledled 10w - AliExpress

https://www.aliexpress.com/store/product/10PCS-100PCS-Luminus-SST-40-10W-LED-1100lm-Cool-White-7000K-instead-of-CREE-XML2-XM/1966839_32819284669.html

https://www.aliexpress.com/item/10PCS-100PCS-Luminus-SST-40-10W-LED-1100lm-Cool-White-7000K-instead-of-CREE-XML2-XM/32819284669.html
Funny, it appears renamed to “GreatLED Store” from shenzen

Like KDlight DTP Mcpcb is 1.5mm thick, Noctigon is 1.6mm thick and SinkPAD-ii is 1.65mm thick. (Is there anymore available DTP Mcpcb’s out there?)

( Vinh uses VTC5A)

KD has VH Voltage binned SST-40’s now.
Has higher brightness bin too.
http://kaidomain.com/Flashlight-DIY-and-Tools/LED-Emitters-or-LED-Star-on-PCB/High-Power-Luminus-SST-40-Voltage-VH-N5-BC-White-6500K-LED-Emitter?sort=p.date_available&order=DESC
Nw only 310 lm typical at 700 mA
170 lm/W typical at 700 mA

https://www.mouser.ca/ProductDetail/Luminus-Devices/SST-40-WDS-F50-N3501
https://www.mouser.com/Search/Refine?Keyword=sst-40

Good luck. I looked over the list and don't think I can answer anything properly, and I thought I know a lot bout LED's.

Some of the questions don't make any sense - like "tint lottery?", "Ring artifacts?".

"tint lottery?" - I thought tint lottery is par for the course with LED's - every brand/model/spec, it's all a matter of binning, both tint and lumens output.

"Ring artifacts?" - I though it was more from the optics, not the LED.

Just fyi, I do like the 5000K tint in the SST-40's, and with KD offering them in bin N5, best of both worlds! I haven't tried one yet, but this is probably the best SST-40 available, maybe for a while, maybe forever.

Well, some leds have more of a tiny lottery and ring artifacts. The xre had unacceptable ring in a smo, for example. Luxeon has a reputation for consistent tint. I am a little concerned that luminus, a Chinese company, might not think twice about qc, tint lottery control. I could be wrong. I am not a fan of any optics other than smo, because I am trying to squeeze out every lumen, Hotspot lux, and spill lux, as possible over a 10 hour runtime.

I do think I like anything from 4000k to 5800 Kelvin, depending on my mood and color that I am inspecting. 5000k (+–300),seems most logical, intellectually, at least. I have 70 cri lights that are 6500k that seem acceptable, and others, same 70 cri and 6500 that I absolutely hate the tint. So I, probably keep under 5700k, just to be safe. I have had green tints, that I would not use, especially back in 2008. Green, and purple, and too far blue tints, which I have encountered, must die.

I apologize for lack of editing, as I am more interested in answers than letting these notes age further on my computer. Thanks for the answers.

Yes, kd, as I recall, had some of the best parts at the best price. Unfortunately, I must order from like 12 suppliers to get all the parts I need for one light. My basement flooded and ruined my 31mm reflectors I had stocked. 36 mm have better spill throw ratio for an XP-L or xml. So, I assume these too… A 26 mm I reserve for the XP-L hi in a single cell, single amc7135. I have no use for a 20 mm reflector…… And, I think the 40 mm too small of a Hotspot. 36 mm smo are hard to find.

Luminus is an american company as far as I know.

You could answer your own questions and order one or a few SST-40 leds, for most people they do not cost a year’s salary.

What I found about beams produced by the SST-40 is that they produce nice, even tinted hotspots without ugly corona’s.