Joule Thief built with BC 549 transistor and toroid.br br By means of an OA81 germanium diode and capacitor in parrallel with the 3 led's , I can charge a 4700 uF capacitor up to around 5 Volts dc, which is supplying a basic LED flip flop circuit built from discrete components.br 2 x BC 549, 2 x 100 k, 2 x 680R, 2 x 22uF, 1 x blue, 1 x white LED.br The current drawn from the "flat" 1.5 Volt battery is about 23 mA's and the Voltage is 1.12 Volts.br The LED's are still flashing happily 4 hours after the video was taken.br br 17 May 2009 Flip Flop is still going fine. ( 4 days later )br Battery is down to 0.45 Volts, LED flash ratio is 3 Hertzbr br The stabilty of the circuit is excellent !br br More experiments will follow soon.