Introduction: Low Power Consumption Joule Thief

About: I had a long break in my online activity, bad things happened in my life and i'm still trying to recover, sorry folks that i was away for a long time and please be patient with me, i will be better in time, i …

This is a improved version of the "traditional" JT, the idea is to obtain a very low power consumption. I seeked a way to light a 3v LED with as low as possible battery drain.

Direct link to bigger schematic image

Step 1: Schematic

Here is my schematic and the schematic for a standard JT.

Parts List :
Q1 - BC547C
R1 - 1k 1/4W
SW1 - Switch
C1,C2 - 10nF ceramic capacitor (marked with 103)
D1 - 1N4148
LED - any 3 volt led
a toroid ferite core and wire
see my outhe instructable for details on how to make the winding

Step 2: Observations

#1 - the cap in paralel with the LED lowers the drain of the LED resulting in the posibility to add more leds
#2 - on same settings bettery drain :
2N3904 - 20mA
2N2222 - 41mA
BC547C - 2,6mA

BC547C saturation voltage is 0.2V

some calculations :

(1.5V x 0.0026A) / (3.2 x 0.0013A) => 93,75%