Laser Pointer Forums - Discuss Laser Pointers | High Power Lasers

Hey,

I bought 3 DVD drives. So, i got 6 diodes (3 red and 3 IR).

I'm using this LM317 driver: http://laserpointerforums.com/attachments/f42/11711-diy-homemade-laser-diode-driver-lm317_components01_001.jpg but i added one more resistor of 5 Ohms. So the final resistance is 2.5 Ohms.

I tried 4 diodes (2 red and 2 IR). All of them were normal. Red were really bright. But after about 10 minutes, all diodes just reduced their brightness for about 5%. (current (220mA) and voltage (2.7V on diode) were the same as when they had 100%)

I'm using heatsink and they weren't even heating.

Any ideas ?

Thanks a lot ! and sorry for my bad english Hope you'll understand my problem.

:thanks: