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Can anyone identify this diode? (pic heavy)

Misellus

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Closed can, 5.6mm, marked SI767AUD82 (not 100% sure about the 8, it's blurred)

3 pins at 12 o'clock 3 o'clock and 6 o'clock like most other diodes I've seen.
Original solder pad connected at 12 and 3 o'clock positions.

2 lenses on the front, one square and one round, both have a blue tint.

I have a number of these. None give more than a dim red when 4.5V to 6V applied to 12 o'clock pin and 3 o'clock pin grounded. I've tried 20mA, 30mA, 40mA, 150mA, 200mA, and 290mA. I also tried 2 different drivers, one Aixiz and one DDL. Never more than a dim red. I checked for IR by viewing the beam through the camera on my phone. It was visible but also dim.

They were sold to me as low power (5-20mW) 650nm, but unless they've all gone LED, I don't think so...or I've managed to burn out every one I've tried so far (6 or 7). My best guess is 5mW IR but I don't know for sure.

Any help is appreciated.
Misellus





 

RA_pierce

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They look like 780nm near-Infrared diodes. >2V will kill them. Depending on what DVD reader/writer they came from, they could be capable of 5mW or >150mW.
 
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Misellus

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Okay, thanks for the info.

Sounds like I probably did burn out all the ones I tried since I definitely gave them too much voltage :)

They're not what I wanted but it's something new to learn.

Misellus
 

qumefox

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How are you driving them? Usually you set current and the voltage will float at whatever gives that current. It really depends on the driver though, but you should NEVER hook a LD to a constant voltage source.. You always need a properly limited constant current source.
 

Misellus

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They were never hooked directly up to a voltage source. The first 3 or 4 (the low current attempts) were done with a DDL driver. The last few (the higher current attempts) were done with an Aixiz driver. While I was confident I had built the DDL correctly, and the test load was reading what I expected, I did have some doubt so wanted to try a pre-built driver just in case. I also wondered it I just hadn't reached the threshold current with my early attempts, so upped the current output.

With the DDL driver, I measured voltage across the diode as 1.89V. I thought that was low so should have realized then that I was dealing with IR...but this is the first time I've worked with an IR diode and since I was told they were visible red, I didn't make the "~2V==IR" connection even though it's something I knew from reading here. I thought something was wrong with the diode instead. So I junked it and tried another...which was also dim.

I never measured voltage across the diode when using the Aixiz driver. I can try that tonight, just for curiosity's sake.

Tonight I'll make a DDL driver set for 150-180mA and run it off 1 LiIo cell. That should get the voltage and current about right. Since the diode took 200 and 290mA, 150-180 should be just fine.

thanks for the help
Misellus
 

Misellus

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That looks like the IR diode from the LPC sleds :)
Confirmed with the seller. He said he sent the wrong packet and offered me a discount on a future order. So all's good on that side.

So, mystery solved, thanks all
Misellus
 




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