See also " larskro" Channel
Power from a nearly totally dead battery.
This Joule Thief work at a very very low input voltage from 0.035 to 0.080 volts and the output voltage is 2.7 volts, to the LED. An ordinary Joule Thief work down to 0.6 to 0.8 volts, because of losses in the transistor.
This transistor STN841 is a low drop type.
Correction Transistor: 2 is the collector and emitter is 3.
NPN 5 amps 120 volt.