Joul thief how to? Answered
I've been reading some ibles about joul thief making, and most of them teach how to power an LED with a 1.5v AA battery. That is great, if you want to power an LED with a 1.5v AA battery :)
But what if I want to keep using old, weak AA batteries, as 1.5v batteries? How do I make a joul thief that takes whatever the battery can give it, and outputs it as 1.5v?
I know the kind of transistor, ferrite core, number of windings and wire gauge all affect output, so how do I know what to use?