What LED is this?

[Fallingwater]

I got a few of these at a really low price some time ago. Seller said they're high-flux, but didn't say anything else. Figured for €0.3 a pop I couldn't lose, so I got a few. Never actually used them for anything up until now, but now I have a project in which I could use them, so I'd like some more data.

I can't actually see the die shape under the dome, by the way. Also, that's not rust on the square metal part - it just looks like it after auto-leveling the picture. It just came up of a deeper colour in the picture.

 

[-Gast-]

Looks like Cree XL-Series
http://www.led-tech.de/de/High-Powe...erie/CREE-XL-7090-Emitter-LT-1277_120_79.html

 

[Illum]

I think -Gast- might be right on this one...
if the corners were dropped it would resemble Nichia NS6W183T

 

[Fallingwater]

Huh. I thought I was getting cheap generics, didn't know genuine Crees could cost so little.
Do they use the same die as the XR-E package? It seems doubtful considering the price, but y'never know...

 

[BikerBob]

Sometimes, you just can't identify the exact part number/specs for a component, unless the supplier provided the information. I've got a box full of unmarked/salvaged LEDs (mostly indicator lights). No idea what the specs are. When I go to use one, I connect an adjustable bench power supply, and see what voltage/current the LED is happy with. Then I look at the brightness. If it is good enough for my application, I use, it. Otherwise, I find the others in the box that look similar, put them in a small zip-lock bag, along with a small note of what voltage/current they seemed to like. Sort of writing your own datasheet.

So many vendors use similar packages for different parts, you really can't tell exactly what you have based on appearance. Think of how many different LEDs come in T-1 3/4 (5 mm) water-clear packages.

...Bob

 

[Illum]

Huh. I thought I was getting cheap generics, didn't know genuine Crees could cost so little.
Do they use the same die as the XR-E package? It seems doubtful considering the price, but y'never know...

probably not, CREEs don't just make XREs...but it was interesting to note that the dies used in their lines were reflected in other series
XRE-XPE-MCE
XRC-XPC
XPG is currently an oddball.

CREEs also make piranha LEDs as well as 5mms, so much variance exists below the well known high powered LED lines

 

[WeLight]

Yes these are either XL7090 or 3XL7090. The first is a 1 watt generic, the latter A 3 watt, this was when Cree made dedicated power leds. the cloudy phospher was how they made this early leds. I would recommend you bake this led at 80 D C for 24 hours before reflowing

 

[narey]

hi,fallingwater, i like your signature,which makes perfect sense!

 

[Fallingwater]

I'm having trouble soldering to this. I can't reflow (I don't have a reflow oven and I don't have anything to reflow the LEDs on), so I'm trying to solder wires to those tiny tabs on the sides, but solder won't stick and I'm afraid to crank the soldering station to 450°C for fear of damaging the LED.

What efficiency can I expect out of these compared to, say, a XR-E P4?