Sounds interesting, tho if it was in Elektor its a copyrighted design... but you could post up the gist of it for information.... personally, with the cost of PSUs on eBay in the £20 region its hardly worth building you own in many cases... I have a 0 - 20v bench supply @ 5A I built 20y ago, when I had access to unlimited MIL spec parts lol, but hardly ever use it, since a fixed 5v and 12v supply suffices for most things PIC-based these days. Rarely do any discrete analogue stuff now....