Put Switch on the primary with fuse protection on primary & secondary. The reason is that a transformer will still consume some power - iron loses - when left connected to the supply. ************************************************* Roy Hopkins rdhopkins@ihug.co.nz ************************************************* > I'm about to put together anothe 5V power supply. You know the drill: > diodes, 2200s, 7805, .1, .33 caps. But, I'm going to put a switch on this > one. Should it be on the supply side (OK, that won't work) but should it be > on the input side, or on the output side? Thanks guys, > Colin --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.554 / Virus Database: 346 - Release Date: 20/12/2003 -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu