Here is another I've looked into. http://archives.e-insite.net/archives/ednmag/reg/1998/021698/04di.htm (about halfway down page, look for '5 to 24V switcher') It's 5V to 24V, and regulated. It runs fine as speced, could it be tortured to go to 1.5V supply? I don't know enough to recalculate the resistors to drop the input voltage down, but would truly appreciate someone explaining (slowly, in words of just a few syllables) how to do such a redesign. I imagine the tricky part is getting the regulator transistor to work with the low voltage headroom, since it has to share the headroom with the second half of teh oscillator. That's where my 2 neurons finally gave out. alice > The circuit looks simple enough, i'm not > convinced that it can be converted to > regulate and give top performance but it's > a good starting point. Thanks! > -Roman > > > > Octavio P Nogueira wrote: > > > > This circuit is at > > http://www.e-insite.net/ednmag/index.asp?layout=article&articleId=CA90758&pu > > bdate=07/05/2001 > > > From: "Alice Campbell" > > > > There was also a one-cell LED flashlight in Electronics Design about a > > month ago. It uses 2 transistors and a simple inductor. They mentioned in > > the text that another transistor could be added to get some regulation. I > > would send the ckt but its at home just now. I have tried the ckt but it > > appears to be touchy, I didnt have exact resistor values and had a hard time > > getting it to go. But the leading indicators are that it is possible to > > torture this ckt into an SMPS. I will send ckt later. > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > > -- _______________________________________________ FREE Personalized E-mail at Mail.com http://www.mail.com/?sr=signup Talk More, Pay Less with Net2Phone Direct(R), up to 1500 minutes free! http://www.net2phone.com/cgi-bin/link.cgi?143 -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu