While surfing for more LED information, I found this rather nifty little circuit on Electronic Design’s website. It’s a little Joule Thief-like circuit, but with enhanced efficiency (~80%) and it can drive white LEDs with rather large forward voltage drops. Archived for later….
See my blog for details about this circuit.
http://watsonseblog.blogspot.com/2011/05/2011-may-11-electronicdesigncom-jt.html
The ED link is bad, here’s the current one: http://electronicdesign.com/energy/single-alkaline-battery-drives-white-led