Roman Nice results & well presented - I had a feeling that this circuit had some potential! Your version is now firmly copied into my "useful circuits" file. Richard P (Posted on [PIC] and [EE] as this is a 5v regulator design.) I think i've found the "holy grail" of 2-transistor 5v SMPS regulators! After seeing the recent discussion on using a 5v switching regulator chip I went back and spent a few hours on my 2-tran SMPS regulator with the goals of improving efficiency snip..... -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body