Thanks for the info. I have been out of town all week and only get a quick chance to check posts. I'll be making one opf these up in the near future, but will use the full voltage version for the moisture meter. It basically puts a voltage through lumber and checks the resistance, so I am assuming it needs full juice to keep the meter properly calibrated.
I do need to use it for work, but mainly as a gee-whizzzz tool for the customers :D