anachrocomputer:
Joule Thief: toroid, as found
anachrocomputer:
Joule Thief: first version of coil
anachrocomputer:
Joule Thief: The BC548B transistor
anachrocomputer:
Joule Thief: The Mark II inductor
anachrocomputer:
The complete Joule Thief
anachrocomputer:
The Joule Thief, working
anachrocomputer:
Ferrite cores for Joule Thief
anachrocomputer:
Transformers for Joule Thief