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I finally completed my DIY red burning laser. Been working on it feverishly all day, and it's finally done. It's a hack and it's not going to win any beauty contests but I'm proud of it.
I ordered two of the Sony diodes from the Senkat group buy months ago (in August) and I'm happy to say no diodes were killed making this laser. I got lucky. So I have a spare bulb if the current diode dies.
I used Daedal's circuit (see this thread: http://www.laserpointerforums.com/forums/YaBB.pl?num=1185701612) to drive the diode. I ordered the diode housing and optics from Meredith (see:http://www.mi-lasers.com/cgi-bin/shopper.cgi?search=action&keywords=diode_optics).
Once assembled I slowly turned up the pot while metering things with my old radioshack analog multimeter. It was so satisfying to see the diode come to life and slowly brighten as I increased the current. I carefully metered it up to 225 mA. I decided to stop just short of the 250 mA mark. Though I could easily push more than 300 mA of current through the diode by adjusting the pot I'm going to be a little conservative. 225 mA of current should put the power output well over 100 mW.. possibly over 150 mW if the diode is efficient. It certainly burns like a 100+ mW laser.
Below are couple of pics of the laser box. I assembled the laser housing using the covers from an old hardcover book. An X-acto knife and lots of epoxy glue completed things.
Close up of the innards. Yeah it's messy. I just wired the circuit around the pot. I'm using NiMH batteries because they can easily supply the needed current (unlike alkaline batteries) and they have a very flat discharge rate. The most sketchy part when soldering things up were attaching some 20 gauge copper wire directly to the diode legs to increase their length. Not fun but I did it.
I'm not satisfied with the Meredith housing. Whenever I focus the lens the diode sometimes turns also so I have to be careful. I'd like to look into other options for my next laser. Visually the laser is bright, though it doesn't appear much brighter than my (homemade) beast 25mW 635nm pointer... however it burns like a 100+ mW laser. Final picture shows it smoking some black plastic from about two feet away. Once I focus it down anything within about a meter is going to have to deal with a lot of red photons. Safety matches will go up within a few seconds and I was able to cut through a section of black electrical tape in under 5 seconds.
How else can I measure its burning prowess?
Anyway, it was a lot of work but it's immensely pleasing to see it working.
I ordered two of the Sony diodes from the Senkat group buy months ago (in August) and I'm happy to say no diodes were killed making this laser. I got lucky. So I have a spare bulb if the current diode dies.
I used Daedal's circuit (see this thread: http://www.laserpointerforums.com/forums/YaBB.pl?num=1185701612) to drive the diode. I ordered the diode housing and optics from Meredith (see:http://www.mi-lasers.com/cgi-bin/shopper.cgi?search=action&keywords=diode_optics).
Once assembled I slowly turned up the pot while metering things with my old radioshack analog multimeter. It was so satisfying to see the diode come to life and slowly brighten as I increased the current. I carefully metered it up to 225 mA. I decided to stop just short of the 250 mA mark. Though I could easily push more than 300 mA of current through the diode by adjusting the pot I'm going to be a little conservative. 225 mA of current should put the power output well over 100 mW.. possibly over 150 mW if the diode is efficient. It certainly burns like a 100+ mW laser.
Below are couple of pics of the laser box. I assembled the laser housing using the covers from an old hardcover book. An X-acto knife and lots of epoxy glue completed things.
Close up of the innards. Yeah it's messy. I just wired the circuit around the pot. I'm using NiMH batteries because they can easily supply the needed current (unlike alkaline batteries) and they have a very flat discharge rate. The most sketchy part when soldering things up were attaching some 20 gauge copper wire directly to the diode legs to increase their length. Not fun but I did it.
I'm not satisfied with the Meredith housing. Whenever I focus the lens the diode sometimes turns also so I have to be careful. I'd like to look into other options for my next laser. Visually the laser is bright, though it doesn't appear much brighter than my (homemade) beast 25mW 635nm pointer... however it burns like a 100+ mW laser. Final picture shows it smoking some black plastic from about two feet away. Once I focus it down anything within about a meter is going to have to deal with a lot of red photons. Safety matches will go up within a few seconds and I was able to cut through a section of black electrical tape in under 5 seconds.
How else can I measure its burning prowess?
Anyway, it was a lot of work but it's immensely pleasing to see it working.