Make a Joule Thief  Picture of Make a Joule Thief Yes, it's the
infamous Joule Thief, in Instructable form! For those of you who
don't know, the Joule Thief is a tiny little circuit that allows
you to drive a white or blue LED from voltages as low as 0.5
volts. You think those batteries are dead? Don't throw them out
yet! Hook them up to the Joule Thief to squeeze every last drop
of energy out of them!  The idea and circuit came from this Make
weekend project. Why don't you pay them a visit? Remove these
adsRemove these ads by Signing Up  Step 1: Parts and Tools
Picture of Parts and Tools For this project you will need very
few tools and parts, as you will see in the picture below. But
for those of you who like it in text, here it is:  Helping Hands
(Optional) Soldering Iron 2N3904 Transistor or equivalent 1k
Resistor (Brown-Black-Red) Toroid Bead Thin wire, two colors
(magnet wire works)  You can get the toroid and transistor from
a dead CFL; the transistor is usually labeled 13002.  Also, if
you use a 2N44