I'll start with a stupid question: If USB provides +5V power, why does the DC power input jack need 9-12 V? Won't the 78M05 voltage regulator burn most of that up?
Next question: I'd like to get an Arduino running off of batteries (efficiently). Once I had things working on the Arduino USB, I thought I'd pick up an Arduino Mini (aka the Arduino Stamp) and use it with some sort of switching voltage regulator.
If the Arduino USB typically uses 50-100mA (mentioned in this thread), should I expect the Arduino Mini to be much lower?
Thanks! This little Arduino has my brain spinning in all sorts of new directions!