Windstream wrote: Okay, each LED draws about 20ma of current and needs 2 volts. You need to use a resistor to drop the voltage down 10 volts. Nope , they make solid state regulator units . Got two of 'em on the PCB of the DRO I built from a kit . One does +1.5v for chinese scales , the other +5v for quadrature scales 40 bulbs, wired in parallel, at 20ma each comes to 800ma.