Three Oslons tested: 1) latest gen. Oslon Black Flat 2) SSL80 4000K 92CRI latest gen. 3) SSL80 4500K 96CRI 1 gen. before latest

Luck?
I thought most people used hot air when reflowing SMD components?

Just do it the way you like and if you fail try mentioned OL method :+1:

I am looking forward for tests.

BTW Heat gun and hot air station are not the same to me.

Yeah I meant the hot air thingy that’s smaller than the gun.
I will try one the OL method first, if that doesn’t work I will try with hot air + solder paste.

I use a hot plate and an old pan…works great for me.

I couldn’t use hot air, was too slow and not hot enough. Ended up using soldering pen old-lumens style.

The first time I reflowed it, the LED pads didn’t connect, so I tried again but forgot I rotated the PCB 180 degrees and accidentally soldered the LED backwards and blew it while testing xD
Luckily I bought 10 of them!
Next two LEDs I reflowed worked well.

I did two LEDs, since I only had two MCPCBs.
I was short on time, so the second LED (which I did a better reflow on) I only tested 3A-5A.
Here are the results:

As you can see, the second LED was reflowed a bit better and is getting higher output.
The X axis is amps, the Y axis is relative lux, so you just use that number for comparing. Ambient light was 7 on the y-axis.

As you can see, my large CPU heatsink with fan cooling and MX-4 thermal paste does not peak at 4.5A, or even 5A.
My power supply could not do over 5.2 but the output seems that it would keep going and peak at about 6-7A.
Very good results IMO, and driving it at 6A should give me even higher intensity than in DJozz’s tests since it won’t start dropping at 4.5A :smiley:
.
REMEMBER I measured this is just for me, since my “flashlights” use extreme cooling. For realistic results in a normal flashlight don’t pay attention to this graph :wink:

Nice results Enderman, well done!

The max at higher amps can also be explained by a better led, by accident or not. My led (just 1) was tested already 1.5 years ago, Osram may have improved the thermal properties in the meantime without officially calling it a new version. I say that because there is indeed a new version out, the Black Flat S, but just in multiled form, with better thermal performance. They may just used that improvement for the single die version too without telling.

True, definitely the possibility of a better bin or revision.
What kind of cooling setup did you use in your tests?
My heatsink was at least 100W of cooling capacity, with a 120mm fan and copper plate and heat pipes.
MX-4 is also some of the best thermal paste that isn’t liquid metal.
.
In the actual flashlight build I will be using liquid metal, it even more heat conductive than solder :slight_smile:
I would totally buy a 7 or 8A buck driver from MTN electronics, if they had one :frowning: seems like the Black Flat could take it.

Thanks Mr. Enderman,
Properly re flowed and pressed led(solder as thin as possible) will perform better than one that is re flowed without press and has thicker solder layer between led and mcpcb. That is imho and ime and with classic lux meter test of same types of led I did years ago.

I am really interested how would they perform in single cell FET lights.

Mr. Enderman any chance you could start up group buy for this led? Or any of you guys of course?


Ha :slight_smile: Djozz is not joking when he does his test :+1:

Yeah I did press the second LED down better, that could be it.
Either way it does seem like all the LEDs are the same bin like it says in the datasheet.

They will not be good for direct drive, unless you are ok with less current.
At 4.2v the LED only took 2.5A, and to get it to 5A it required 5v.
Direct drive with a single cell would make it run at ~2-2.5A which isn’t very high.
I recommend a CC buck driver for people who want to drive this LED hard.
(at least this is what the power supply showed me, I didnt have time to check it with a voltmeter)
On second though, the 3ft of wire might have made a difference, I bet the voltage drop at the LED is actually less than what the power supply showed.
Maybe like 1v less? that would be more similar to DJozz’s results…

Nice, I think my setup did provide better cooling than that since it didn’t have a huge copper column that heat had to travel through.
What thermal paste do you usually use?

2.5A at 4.2V sounds far outside normal voltage variation for the Black Flat.

Yeah it was probably just the power supply.
Now that I know it won’t burn up I will do a test using my MTN max 6A driver and measure the voltage at the LED.

And build one small light with FET driver please :smiley:

DTP friendly P channel MOSFET driver
17mm and bigger

did 17mm Oshpark
and 17-24mm Seeed design

Still no reply’s for this revolutionary driver?

Lexel when we can expect it and how much it will cost?

I see MCU there but is it possible that you individually re flash it for costumer demands (I need only Turbo, mid, low without memory effect so it always starts on high.

The parts price will be around 1.3$ less than the other Narsil/Bistro drivers, as the FET is cheaper and no AMCs

The MCU can be Attiny 13a, 25 and 85 or other
Pin 3,5 and 6 are bridged to the single FET, so it is possible to run different 1 channel output firmwares

@Djozz: thank you for testing the Black Flat two years ago! Because of you my big thrower now does 1.7Mcd. We all might have never noticed this LED if you hadn’t tried it.

You’re welcome. But my own first test in a Brinyte B158 made me believe that in practice this led was not so great as the test suggested. Must have been an imperfect reflow. Good that you guys went on with this led. :slight_smile:

I got the first batch 17 and 20mm boards produced