Thanks
I think I'm getting it, but let ask some dumb questions just to make sure.
If I install a diode (forward bias) it will act like a resistor and I get a voltage drop? (If so, very clever.)
Could I use a 1N4004? Looking at the specs, (hope I reading this correctly) it has a forward voltage drop of 1v
Is 4.5v good enough to power the Arduino?
1N4004 is rated at 1a average. Could I use 2 or 2 in parallel to get 2 or 3a? Or is that a dumb idea.