After reading this, and then this, I started thinking of how easy it would be to make a burning laser. I went to Radioshack, got some components, and started thinking. One thing that Stephanie's laser didn't have is a potentiometer, to control the power of the laser. Well, I ended up getting 12 assorted pots at Radioshack, but didn't know what one to use. I want decent control, too. What size (in ohms or k-ohms) do you think I need? I'm spotty in my electronics knowledge.

PS- The size in ohms on the pot is the pot's range, right? If it says 100k, it means that it will resist from 0 to 100 kilo ohms, right?Also, in the shematic below, I don't know if the pot is connected correctly, post a comment if it's wrong.

Picture of Laser
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beamq2 years ago

Every kind of laser have a part of infrared laser. DIY laser doesn't have IR filter, you need some laser safety goggles to protect your eyes.

lemonie10 years ago
Do consider energy:
Can you get enough power out of 3 AAs to burn anything?
Can you shove enough energy through your laser to burn anything?
How much power output do you need for a burning laser?
Answer these first, before drawing schematics.

deej397 lemonie7 years ago
juel effect?
John Smith (author)  lemonie10 years ago
-not sure, (I'm using 2 1.5v AAA batteries, not 3)
-don't really know what you mean, do you mean to say: "do you know how " ?
-by power, do you mean voltage, or what? I guess 2 1.5v AAA batteries won't give me much, but Stephanie in the second link above got away with 2, 1.2v AA batteries, so...
I know I'm not considering current, What do you think? I'm planning to use a DVD laser. I think I read that Stephanie had a DVD laser running on 3v from three AA rechargeables, but they were limited to 3v by a silicon diode, with a voltage drop of .6v (three rechargeables alone would give 3.6v - one alone is 1.2v) She was running a average of 200mw, and was actually able to run it (underpowered) on 2.4v (2 rechargeables).

What do you (and anyone else) think?
I mean, how much power do you need to cut stuff? Let's say you need 50w as an example, that's ~17 amps @ 3v and you're not going to get that out of AAs. Maybe you could drive 4A through this @ 12v, but wouldn't this destroy your laser? 200mw won't cut much, spider silk maybe...? L
John Smith (author)  lemonie10 years ago
I don't know...
AAA batteries are going to supply considerably less current than AA would. It's the current that does the work which is what you're adjusting with the rheostat (potentiometer in that configuration). I would modify the experiment circuit by continuing the open end of the potentiometer to the same line as the tap (+ on the batteries). It wouldn't change the functionality of the circuit but would assure a connection if the brush floats or bounces.
John Smith (author)  LasVegas10 years ago
Ok, thanks. Do you think that the 2 AAA batteries will even supply enough power? I was afraid of that from the beginning.
fiddle-fart8 years ago
what about adding some kind of a capacitor to build up a single shot of laser light. what would you need to do something like that ( like a laser phaser)
John Smith (author) 10 years ago
Well, it is a laser. I don't know if you could add more current to give more power through the laser, but my guess is that it would burn it out. Somewhere I read that you can change the power by turning the small pot on the diode's circuit board. Not sure about that.
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