Sceadwian
Banned
If you want to try for a little more voltage try winding a smaller tighter coil with longer thicker wire. The coil gets bigger but you may get higher voltage out, depends on quiet a few things. They're not particularly efficient though. While it's fun to play with joule thiefs if you want a little more fun and a lot more experience try hunting around for one of the many IC based SEPIC converters (a sepic converter can both buck (decrease) and boost (increase) the native voltage. Usually only a few discrete components are required to chose the regulated voltage and they can be powered from single AA level voltages or higher. They're not too expensive either.
