Build a Joule Thief
Parts list:
www.nottinghack.org.uk
Ferrite core
BC548 NPN transistor
1k resistor
LED
Wire
Solder
Making the transformer
Take two different
colour wires
C
B
Wrap around the
ferrite core
C
B
BC548
E
E
Flat side
Keep the two wires
in order
Put around 7-10 turns
(no more)
Cut ends to same
length
+ve
Connect different colour
wires from different ends
together
More details:
http://www.emanator.demon.co.uk/bigclive/joule.htm
http://www.evilmadscientist.com/article.php/joulethief
-ve