> I haven't had to use a pre-regulator before my regulator in anything but a > precision benchtop power supply. I wonder if there is a cheap automotive > 5V regulator that will handle 48V DC input voltage without complaining? That's a pretty large drop proportionally. At 48V in 5V out efficiency is about 10%. How about a simple buck converter? ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics