So I got my hands on some 40W diode laser modules (rather cheaply) in the hope that getting my DIY Laser CnC project off the ground. Originally I was fishing around for a CO2 setup but these were going cheap ($50) compared to similar powered CO2 setups ($500+). Anyway, the question I'm left with is: How do I power these things? Looking at this simplistically - they're just like LEDs. They have a forward voltage (typ around the same as a small LED, 1.5-1.7V) and are totally dependant on current limiting or they'll blow up. So, I'm looking for ideas, and I'd really like to have the ability to vary the current digitally (as to automate the CnC process for material width as well). The diode's parameters are as such: Operating current: 10/40/45A (Min/Typ/Max) Normal operating voltage: 1.6/1.71V (Min/Typ) The problems I'm faced with: * A 1.7V @ 50A power source?!? I figure I'm going to have to start higher with a 12V @ 10A source (for example - widely available) then use a second-stage DC-DC conversion down to the appropriate voltage and control the current from there. * How best to regulate current at that level? PWM? Would the above mentioned "DC-DC 2nd-stage" be the best place to do this? * Feedback for that current level? An integrated package or the old shunt and measure method? * Any circuits around that I provide a good example of where to start? * Pointers for dealing with such high current in PCBs? * Pointers for the overall project? Thanks in advance.