Efficient/High output Joule Thief?
Right now, I am looking for schematics for the most efficient (1 cell and 1 LED) joule thief, to use as a durable reading light. I right now favour Quantstuff's 2 transistor SJT (http://quantsuff.com/LED2.htm) but I am not sure whether it is the most efficient. I've seen several others, but since they all claim to be equally as efficient, i'll have to rely on the experience of other tinkerers and hobbyists. So: what's the most efficient or high current or high voltage joule thief you know of?