I believe a fuse blows out due to R * I ^ 2 heating, which tells me I can use a fuse rated as 1A @ 250V in a design where I want a 1A @ 125 V fuse. Is this true? TIA, -- Rick -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.