I'm trying to build a power supply for an AVR project....
I need +5V regulated for the AVR and +12V for other crap.
Yes, I could just use a 7805 and 7812, but since I want to drive this off of batteries (hopefully?), that's looking like +18V out of two 9V batts. That would be a LOT of heat off the 7805, and lots of wasted power from the batts.
Or does someone have suggestion on a battery to use that might be closer to the minimum voltage. +15V if I recall...