hi in this instructable i will show you how to make a joule theif.this joule theif can be used to charge capacitors.
I charged a 30v 3300uF cap in 5 minutes.
Step 1: PARTS
Q1-D882 or any npn transistor
D1-1n4007 or any diode above 5v
toroid-you will get one from an old cfl
C1-3300uF or any other cap to be charged
Step 2: WIND THE TOROID
wind both wires togather and connect the resistor to the begining of one wire and the ending of the other wire.
Step 3: MAKE THE CIRCUIT
Step 4: FINISHED
TEST IT OUT MINE BURNT AN INFRARED LED.it has a capacitor discharge so led will be illuminated for some time.