Hi!
I've been building a 8-line laser projector using a green laser (200mW) and a spinning polygonal mirror to scan along the horizontal axis. To power the laser, I'm amplifyng the microcontroller's modulated digital output through a transistor (BC548) and connecting the collector to the laser's battery contacts. I've fairly succeeded, but the beginning of the each line is darker than the end. Also, the lines with more pixels seem brighter than the other ones. It looks like the laser takes some time to power up, which is undesirable to my project, as it turns on and off at rates of 20kHz. Should I try to disassemble the laser, remove the diode and build a LM317 driver? Is there any other circuit I could use to power the laser using it's built-in driver? I'm too scared about "killing" my laser, since my project is working already and these lasers aren't cheap.
Thanks!
I've been building a 8-line laser projector using a green laser (200mW) and a spinning polygonal mirror to scan along the horizontal axis. To power the laser, I'm amplifyng the microcontroller's modulated digital output through a transistor (BC548) and connecting the collector to the laser's battery contacts. I've fairly succeeded, but the beginning of the each line is darker than the end. Also, the lines with more pixels seem brighter than the other ones. It looks like the laser takes some time to power up, which is undesirable to my project, as it turns on and off at rates of 20kHz. Should I try to disassemble the laser, remove the diode and build a LM317 driver? Is there any other circuit I could use to power the laser using it's built-in driver? I'm too scared about "killing" my laser, since my project is working already and these lasers aren't cheap.
Thanks!
