Thanks for all the responses. I specifically said "buck converter" because I've used 7805s and know how much heat they put out. I guess I was hoping that someone would point me at the details of one of the cigar lighter adapters, rather than a product that I can buy and cannibalize...
I know that there was a little company doing these and potting them in epoxy. Boost converters, too. They might have disappeared by now but I'm trying to dredge them out. 73, chris
