Step 8: Add the Joule Thief
Big Clive's Blog or How to make a Joule Thief Instructable.
1) Solder the wire from the last coin to the positive terminal of the circuit.
2) Connect a wire from the last aluminium can to the ground terminal of the circuit.
3) The leads from the LED connect to the output of the Joule Thief.
4) Wrap insulation tape around the circuit and gently push inside the can out of the way.