“A joule thief is a minimalist Armstrong self-oscillating voltage booster that is small, low-cost, and easy to build, typically used for driving light loads.It can use nearly all of the energy in a single-cell electric battery, even far below the voltage where other circuits consider the battery fully discharged; hence the name, which suggests the notion that the circuit is stealing energy or “joules” from the source. The term is a pun on the expression “jewel thief”: one who steals jewelry or gemstones. Super Efficient Joule Thief DIY to steal all the last energy from a battery and without any Toroid coil. Save your time to get more effect. In this project i will shows you the combination simplicity of the circuit and a few variants on the design which add extra components to improve efficiency to make one.The materials of this project is a single, general purpose small NPN 2n2222 transistor A331, Resistor 5.6K Ohm 1/4W,10nf ceramic capacitor 103, OA90 Germanium signal diode, 5mm round white led, 20 mA, 3.2 V (Light Emitting Diode) and 83uH tiny Inductor instead Toroid coil.”