infrared laser bu38 808nm 300mw, how to check?

Hello,

trying to create an infrared lighting device with three lasers, ordered on ebay this laser, 3 pieces.

i'm going to use the following driver for this laser


now is the question, how to ensure that the diode works, because I took the red laser diode from the CD, and check the resistance between pins, it shows something, like should show usual diode... in one way something in another - nothing. But when I took this 808nm diode, it shows nothing in both direction. Is it fine? will it work when I connect it to my driver?
here is already soldered drivers which I used for IR high powered diodes and red laser.

and the protection also in place

It should pass current in open direction. If it doesn't it's dead.

Hi,

checked again, all of them are healthy, yet :evil:

what about laser driver, is my structure is enough for this? I use usual PC power-supply for the source.

Please google lm317 constant current and compare against what you've drawn here.
Your laser diode is backwards and your sense resistor is in the wrong place.

Cyparagon said:

Please google lm317 constant current and compare against what you've drawn here.
Your laser diode is backwards and your sense resistor is in the wrong place.

Click to expand...

Hi,

mmm, didn't get your point... I google it and don't see difference with


here is already soldered components

on my soldered device those two resistors by 10 Ohm are missing. When I connect it to the laser, it stabilize the current to necessary 2.2V.

Currently problem is that the LM317 suffer overheating very fast, is it a problem with current schema of the driver, or I have to add more aluminum stuff for cooling?

Excess power is dissipated in heat, so yes you will want to heatsink your lm317

crazyspaz said:

Excess power is dissipated in heat, so yes you will want to heatsink your lm317

Click to expand...

Hi,

thank you for your feedback!
I took the aluminum cooler from the old Athlone. I have devided it by two pieces and fixed them on the 120mm cooler, works better


resistors are still hot, but I will solve it by exchanging for more powerful..