So, I decided I wanted to make my very first foray into some basic electronics. I decided I was going to attempt to make a laser mag-lite, as per this hack here. The steps seem pretty straight forward, so I figured it would make a good first project.
I wound up getting (not thinking about possible differences) the laser diode mount for the DVD reader in the XBox 360. I'm now in post-mortem mode. I extracted the diode with no issue, and through some trial and error I figured out the correct 2 pins (out of four on this diode). Once I got those extended and plugged into the mag-lite, it glowed red for a few seconds, then I started to smell some ozoney-smelling "burning" and then it went out, and now it is apparently dead, and will not light again.
So I'm looking for confirmation/input why it failed, as I have my theory. My working theory is that since this was a "reader" diode as opposed to a writer, it has a much lower energy usage… and so the 3V of the mag-lite batteries were way too much for the poor little diode, burning it out. Is this a likely theory?
If so, would the speed of the burner (16x, etc.) being used make a difference? I don't know if the laser is any different based on the speed or if that just indicates differences in the speed of the spindle and the lens actuators in the laser assembly.
As one related question, in project directions for this kind of project, most of them talk about "finishing" the end project with a laser control circuit. What exactly does the LCC do?
P.S. If someone with the rep could maybe create and tag this Q with the following tags: dvd, mag-lite, post-mortem I'd appreciate it.
Best Answer
Laser diodes are like LEDs in that the more current you put through them, the hotter they get, and the hotter they get, the more current will go through them, which makes them get hotter... and then fzzt.
So yes, as BarsMonster says, without anything to regulate the current (in the simplest case, a current limiting resistor) the laser diode will die immediately.