No I do not need voltage regulation since it will only be powering the LED light. I will be using a LM2576 -5 for my Mcu. What would be ideal is if I can find a switcher that can give me 5V regulated out on one pin and 12v with regulated current on the other. Similar to what the current buckpuck does but I am guessing that is asking too much. I would be happy with limiting to ~640ma with 12V in and <= 12V out.The LM2576 is a 3 amp regulator. If you wanted the circuit to regulate at .64 amps then you would use a 1.87 ohm resistor instead of the variable resistor and R8. If you didn't need voltage regulation then simply remove R 5,6,7 and the switch.