- Joined
- Oct 6, 2010
- Messages
- 11
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- 0
First i would like to say that i have been reading and searching this forum for weeks trying to gather all the info i need, and i am thankful for such a great site. Now i have been experimenting with lasers for a long time, but i have decided to go all in and build a 1w 445nm laser. I have ordered the diode in an aixiz module, and have built a DDL driver using the lm338 instead of lm317. From my research i believe they are pretty much the same, aside from higher current handling. I have built the curcuit in a somewhat weird way, as i have used 10x 10ohm 1/2w resistors, and 5 of them are permanantly hooked up, and the other 5 are mounted to the board but not attached at one end unless jumpers are added so i can slowly step up my power. As far as current goes i am getting almost exactly what i should be +/- 10ma. Now i know the diodes are current regulated, but i am worried about my voltage. Using 2x 18650's in series my input voltage is 7.4 and my output is about 6v. Is that to high for the diode? I used a small DC motor as a dummy load and the voltage drops to almost 2v when pushing 1A. Can a motor be used as a dummy load? The reason i used a motor is because i built the standard dummy load shown in many tutorials here and my results where even more boggling. When building the dummy load, for some reason i was not getting near the .7v drop per diode, and instead of 6 diodes i had to use 9 to get 4.5v drop. When testing with this dummy load, across the resistor(1ohm 10w) i only got about 8Ma, and across the diodes(in4001) i got the same 6v. Anyone know whats going on here? Thank you in advance for the help!