Laser Driver with Limited Parts? Answered
I have been working on a laser engraver for some time now, and have just recently gotten the laser parts. I need to make a laser power supply, which I currently have a 5-volt fixed regulator which turns 15v 380ma into (obviously) 5v with roughly 400ma (value on label is not completely accurate). I know that diodes will drop ~.6-volts, which I have a line of about 7 of them for testing, giving me 2-volts with the same current. The problem I'm having is, I put proper resistors into the circuit to give 200ma to the diode, but every time I attach the laser to test the current it always reads 17ma on my volt meter. Why is this? How am I able to build a proper laser driver with limited parts (limited to a large supply of resistors and mixed caps, no adjustable regulator)?