I sympathize with Olin. He suggests a superior technical solution and his suggestion is shot down for mostly "non technical reasons". cc On Jun 26, 2008, at 3:37 AM, Dario Greggio wrote: Xiaofan Chen wrote: > Say if you have a single-stage buck converter, the efficiency from > 24V->5V will be better than 48V->5V. 12V-->5V is even better. As I wrote in reply to Olin, this enforces the 12V solution - especially since I'm kind of bound to Linear regulators. But the 24V would possibly give e more "headroom" in case where I had long cabling and needed some more current... The good part is that I can change from 12 to 24 almost on the fly, if I ever need it... since the only hard-soldered part on the "little boards" is one small relay - used for cases where a "dry contact" is needed. -- Ciao, Dario -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist