What is it?

[tweezak]

Hey, all! Long time member...first time poster.

Here's my curious object.

They were selling off some stuff at work today and I saw this in a box of fans so I grabbed it. It was only a few bucks and I figured it would give me something to power with the HP E3611A power supply I bought there (for $30 :thumbsup.

The star PCB says "LUMILEDS" but that is the only marking aside from the +/- on the solder pads.

I went to the Lumiled/Philips site and looked at some data sheets and the typical forward voltage they give for most of their emitters is 2.95V to 3.5V.

This is a blue emitter and it doesn't even start to barely glow until 4.6V. Since the forward current indicated on the data sheets was 350mA I set that as the current limit on my power supply. At that limit the bias gets to about 6V. Obviously a diode curve is such that a very large change in current corresponds to a very tiny change in voltage so this may not be a meaningful result.

Anyway, even driven at 6V I don't feel the heat sink getting warm at all so I don't think I'm over driving it.

Does anyone know what LED this might be and where I might find a datasheet for it?

Guesses are also welcome.

Thanks!

 

[wyager]

Where do you work where you find esoteric LEDs lying around (and they sell them to you)? Sorry, I haven't got a clue though. Datasheet mining is a pain, huh?
edit:999th post!

 

[tweezak]

Where do you work where you find esoteric LEDs lying around (and they sell them to you)? Sorry, I haven't got a clue though. Datasheet mining is a pain, huh?
edit:999th post!

Congrats on the post whoring! :devil:

I work at HP. Hence the HP power supply and the mega-overkill HP 3458A multimeter in the background of the photo. I picked that up at the last employee surplus sale for $25 if you can believe it. Where else can you get an 8 digit multimeter for that cheap?

Anyway, we have an excess equipment area and they are thinning down the piles of stuff by selling off the redundant items. Most of the stuff comes from largely automated assembly lines that were taken down and parted out. This little item was probably an illuminator for cameras that did checks for alignment on the assemblies. There were lots of the fan/heatsink combos in the box but this was the only one with an LED mounted on it.

I was hoping it was white so I could make a bike light out of it but since it's blue...I don't know what I'll do with it.

I just thought of something...I noticed when I had it cranked up that stuff like highlighters glowed something fierce. Is there any chance this is actually a UV LED and I'm pushing it too hard and it's saturating into the blue spectrum. If so, I may be damaging my eyes.

 

[wyager]

I wasn't aware that big companies would sell surplus like that. Makes sense I guess. Pick me up an oscilloscope next time you get a chance, will ya'?
:nana:

anyway, it's probably not UV if you can see it that well at low currents. ~450nm is plenty high energy enough to fluoresce highlighters.

 

[tweezak]

I wasn't aware that big companies would sell surplus like that. Makes sense I guess. Pick me up an oscilloscope next time you get a chance, will ya'?
:nana:

anyway, it's probably not UV if you can see it that well at low currents. ~450nm is plenty high energy enough to fluoresce highlighters.

Dunno if you've been following the drama at HP for the last 5 years or so but they will do anything to save money and generate "profit." It's really pathetic. Oh...and about an oscilloscope...if I find one for you it will be because I didn't want it. That was the main reason I went to the sale in the first place.

They did have one really old HP analog scope that didn't even power up. By old I mean probably mid 70s vintage. They wanted 2 much for it...$45. They did have a couple of logic analyzers but I wasn't really interested in one of those. They also were pretty old and big. USB based logic analyzers are relatively inexpensive and work really well for most stuff.

Speaking of o-scopes...do you have any experience with any USB scopes? I see them up to around 100MHz. I'm really tempted to get one because if the performance is as they claim it's a pretty good deal compared to most bench units.

 

[wyager]

I built myself a crappy pseud-o-scope with an ATMega... 0-5v at a few khz sample rate, 10 bit resolution, awesome! But beyond that, I have no experience with USB scopes or logic analyzers. There are certainly some nice ones, ADCs are very advanced nowadays.

 

[tweezak]

I built myself a crappy pseud-o-scope with an ATMega... 0-5v at a few khz sample rate, 10 bit resolution, awesome! But beyond that, I have no experience with USB scopes or logic analyzers. There are certainly some nice ones, ADCs are very advanced nowadays.

Did you build your scope from a kit or from scratch? I see quite a few Atmel and PIC based scope designs floating around. I might just build my own on the cheap. It would be best if I could find my ATMega128 project board from college.

As far as USB logic analyzers...the one they had in the Analog & Mixed Signal lab in school was really nice. It was small and had something like 32 channels. It worked great for what we were doing.

 

[wyager]

From scratch. It's really not that hard, all you really have to do is figure out how to get the ADC set up and then write some software to monitor the serial data from the micro. Actually, if you really want to do it easily, just use a plain old arduino board and they have some really nice free scope programs floating around the internet.
However, honestly, I found almost no uses for it. The one time I really "used" it was to try and sniff out an NMEA connection on this re-branded magellan xPlorist, but that didn't work at all. Plus, the computer side software I was using kept crapping out way before the maximum theoretical speed. The micro was spitting out data at 2MS/S (digital only at these speeds, no analog) but the driver was seriously botched... sort of turned me off of home-built cheap-o-scopes. Maybe the stuff sparkfun sells works better.

 

[tweezak]

From scratch. It's really not that hard, all you really have to do is figure out how to get the ADC set up and then write some software to monitor the serial data from the micro. Actually, if you really want to do it easily, just use a plain old arduino board and they have some really nice free scope programs floating around the internet.
However, honestly, I found almost no uses for it. The one time I really "used" it was to try and sniff out an NMEA connection on this re-branded magellan xPlorist, but that didn't work at all. Plus, the computer side software I was using kept crapping out way before the maximum theoretical speed. The micro was spitting out data at 2MS/S (digital only at these speeds, no analog) but the driver was seriously botched... sort of turned me off of home-built cheap-o-scopes. Maybe the stuff sparkfun sells works better.

LOL!! Sorry it didn't work out better but it makes a good story anyway.

Props for building it anyway. I should try it just to see what I come up with. I have a buddy that works at Maxim and I can probably get samples from TI too. It's nice that I also have a really nice lab at work where I can generate signals to test it properly.

Yeah...I just found the Arduino site a couple days ago. They look like a good starting point for lots of projects.

Thanks for the conversation. Good times.

 

[wyager]

Yeah, well, I guess it "worked" ok, but that doesn't mean it did anything useful.
It was a learning experience. It got me familiar with bitwise manipulation in AVR-C, and also let me know why some people don't use ebay usb-serial knockoffs or third party drivers. :duh2:

TI has some really nice stuff in their sample program if you have the corporate email address and you can surface mount solder, but I'm guessing as an HP employee you have access to that kind of stuff.

And to you as well-thanks for the conversation. The internet is a big place, chances are you find a few people who do this kind of stuff... there are at least a few others on this site who are proficient or skilled at embedded electronics... plus, AVRs seem to be a favorite with driver designers in the flashlight industry so I feel like I'm in good company.

 

[tweezak]

Yeah, well, I guess it "worked" ok, but that doesn't mean it did anything useful.
It was a learning experience. It got me familiar with bitwise manipulation in AVR-C, and also let me know why some people don't use ebay usb-serial knockoffs or third party drivers. :duh2:

TI has some really nice stuff in their sample program if you have the corporate email address and you can surface mount solder, but I'm guessing as an HP employee you have access to that kind of stuff.

And to you as well-thanks for the conversation. The internet is a big place, chances are you find a few people who do this kind of stuff... there are at least a few others on this site who are proficient or skilled at embedded electronics... plus, AVRs seem to be a favorite with driver designers in the flashlight industry so I feel like I'm in good company.

I've been out of school for a couple of years and am just getting back into doing EE stuff in my spare time. It's amazing how fast you forget things. Don't be surprised if I come back to pick your brain.

I love soldering...surface or through hole. I need/want to get a little toaster oven from the goodwill. We used one in the AMS lab and it made our surface mount boards look really professional. Just get yourself a tube of solder paste and use it sparingly and you won't get bridging.

 

[M@elstrom]

Does anyone know what LED this might be and where I might find a datasheet for it?

Guesses are also welcome.

Hmmm... :thinking:

I'm thinking it might very well be a Lumiled's Luxeon V as detailed in the PDF file located HERE now obviously a discontinued product, it's nominal Vf is rated @ 6.84v :thumbsup:

Going for the additional milk and cookies award... I'll add the heatsink/fan combo is "old school" from the Pentium II era

 

[wyager]

I've been out of school for a couple of years and am just getting back into doing EE stuff in my spare time. It's amazing how fast you forget things. Don't be surprised if I come back to pick your brain.

I love soldering...surface or through hole. I need/want to get a little toaster oven from the goodwill. We used one in the AMS lab and it made our surface mount boards look really professional. Just get yourself a tube of solder paste and use it sparingly and you won't get bridging.

The only SMT soldering I've performed was with a soldering iron-luckily they build transistors to be really heat resistant nowadays. :duh2:

Hmmm... :thinking:

I'm thinking it might very well be a Lumiled's Luxeon V as detailed in the PDF file located HERE now obviously a discontinued product, it's nominal Vf is rated @ 6.84v :thumbsup:

Going for the additional milk and cookies award... I'll add the heatsink/fan combo is "old school" from the Pentium II era

Good detective work! :twothumbs

 

[tweezak]

Hmmm... :thinking:

I'm thinking it might very well be a Lumiled's Luxeon V as detailed in the PDF file located HERE now obviously a discontinued product, it's nominal Vf is rated @ 6.84v :thumbsup:

Going for the additional milk and cookies award... I'll add the heatsink/fan combo is "old school" from the Pentium II era

Nice work on the LED identification! Your prize is a free drink from any Starbucks location! Just tell them you are the LED Contest winner and you want your free drink. You can even use my name if necessary. :twothumbs

I'm thinking the heatsink is for any SocketA motherboard. The fan is from Radio Shack and was probably purchased separately. You were close enough on that so go ahead and tell your barista that you get a free scone with your drink too. Congratulations!!

 

[Mark620]

Now run that thing at 700mA at 6.84v and you will need to turn the fan on...

Hmmm... :thinking:
I'm thinking it might very well be a Lumiled's Luxeon V as detailed in the PDF file located HERE now obviously a discontinued product, it's nominal Vf is rated @ 6.84v :thumbsup:

Going for the additional milk and cookies award... I'll add the heatsink/fan combo is "old school" from the Pentium II era