I am sorry if this has been covered previously. As you guys can tell from the thread title, I am a complete laser noob. I have been watching tons of videos on youtube of different burning lasers. I recently purchased a 2W 445nm M140 laser diode and housing from ebay. I will paste link later. I only bought the 2W as it was a few bucks more than a 1W. However, I only want to run it at 1W since this is my first build and do not want to burn it out.
I have seen many sources that state you can successfully run the laser with an LM317 driver. My host is a Smith & Wesson LED flashlight that I had laying around. The power source is three AAAs. I have build the driver using an LM317 as a current regulator. I have used a 1 ohm resistor to get it as close to 1 watt as possible (the resistor test at 1.4 ohms). I get a very dim beam. A voltage test shows 1.2V and I get nothing when testing the current. If the calculations are correct, I need about one amp to achieve one watt (1.25V * 1A = 1.25W). I then calculated 1.25V / 1A = 1.25 ohm resistor. Shouldn't that be a nice bright beam?
Can someone tell me what I am doing wrong? Do I need a more sophisticated driver?
Link for the diode and housing I purchased-
2W 445nm M140 Blue Laser Diode in Copper Module w Leads Three Element Glass | eBay
I do apologize if this has been discussed. I did not see what I was looking for in other threads. Please point me to the correct thread if there is another discussing this issue.
Also, If I bypass the LM317 and just run one AAA in series with the 1 ohm (1.4 ohm) resistor, it does not light up at all. Not sure if that is relevant.
Thank you in advance for the feedback and patience.
I would also like to add that I am dead set on building this thing from scratch as much as I can. That is why I am using the host that I picked. If any pictures would help, please let me know.
I have seen many sources that state you can successfully run the laser with an LM317 driver. My host is a Smith & Wesson LED flashlight that I had laying around. The power source is three AAAs. I have build the driver using an LM317 as a current regulator. I have used a 1 ohm resistor to get it as close to 1 watt as possible (the resistor test at 1.4 ohms). I get a very dim beam. A voltage test shows 1.2V and I get nothing when testing the current. If the calculations are correct, I need about one amp to achieve one watt (1.25V * 1A = 1.25W). I then calculated 1.25V / 1A = 1.25 ohm resistor. Shouldn't that be a nice bright beam?
Can someone tell me what I am doing wrong? Do I need a more sophisticated driver?
Link for the diode and housing I purchased-
2W 445nm M140 Blue Laser Diode in Copper Module w Leads Three Element Glass | eBay
I do apologize if this has been discussed. I did not see what I was looking for in other threads. Please point me to the correct thread if there is another discussing this issue.
Also, If I bypass the LM317 and just run one AAA in series with the 1 ohm (1.4 ohm) resistor, it does not light up at all. Not sure if that is relevant.
Thank you in advance for the feedback and patience.
I would also like to add that I am dead set on building this thing from scratch as much as I can. That is why I am using the host that I picked. If any pictures would help, please let me know.
