> > > It is part of a step-up switcher. You won't understand that pattern > without some basic knowledge of how a coil (induction) works. 'it > smooths current' is almost good enough, but only if you take that to its > logical extreme. As in "it is impossible to instantly stop the current flow in an inductor".. :) -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist