Diode testing??

[Kenom]

is there a way to determine if a laser diode is burned up? Is it like a normal diode and only capable of passing voltage in a certain direction? I've got a module without a power supply so I can't test it. that would suck if it was toast but before I toss it I would like to find out for sure.

 

[robk]

Try to power it up with a current limited power supply - either a lab supply where you can dial up the maximum current, or build a simple current limiting circuit using a LM317 3 terminal regulator. If it's a diode out of a DVD writer, try powering it up at 100mA, voltage set at 3 to 4 V. The voltage is not critical, these are current devices - limit the current and the forward voltage will take care of itself. There is a decent circuit floating around here for a "violet laser supply" using a 317, try that.
Rob

edit: here's the circuit. Thanks to the original poster!
www.tomokadesigns.com/violetlaserdiodedriverup4.jpg

 

[SenKat]

Kenom - you can check it with your multimeter if you have it handy ? Put the meter into the diode check position - It looks VAGUELY like this : ->- )))... on my Craftsman meter....sorry my artwork is so horrible - it is the standard symbol for diode, and mine shows a "speaker" (the parenthesis) putting out sound as well.

OR - you can send it to ME !

Greg

 

[Kenom]

So, theoretically like a traditional diode you should not be able to harm the diode by running it in reverse polarity. I just might send it to you if I can't determine anything SenKat. I might also send my dorcy and my dvd diode to you as well and have ya buy the optics and whatnot and build me a duplicate of yours.