Joule Thief

[Pirate88179]

Jadaro:

This is what I have been using for mine:  (sorry for the crude drawing)  I basically copied Introvertabrate's circuit from Youtube.

Bill

[innovation_station]

i guess today im building a modulator ...

to finish off the unit i have showen ..

i should be able to come up with a simple unit ..

anyhow thats  what im doing today ..

ist!

[PaulLowrance]

If nobody can't get the joule thief to self-run, then it would nice for you to do some efficiency tests. So far the record is ~ 55% efficient while charging an ultracap. I'm sure that could easily be topped with a different wound core, different transistor, etc. Dare I say that the Joule Thief could go as high as 90% efficiency? 

[innovation_station]

http://www.youtube.com/watch?v=YdYhg6un51k

IST

C MY BORG EYE ?

: )

[xee2]

@ PaulLowrance

If nobody can't get the joule thief to self-run, then it would nice for you to do some efficiency tests. So far the record is ~ 55% efficient while charging an ultracap. I'm sure that could easily be topped with a different wound core, different transistor, etc. Dare I say that the Joule Thief could go as high as 90% efficiency? 

Can you post details of how you measured the efficiency? Schematic, readings, calculations, etc.

I have posted efficiency test before and only got about 25%. Attached is the technique I use for measuring output power. Input power is just amps out of battery times battery voltage. This particulate drawing was meant to show how to determine best number of turns for the coils, which is the combination that produces the highest output power rather the the highest output voltage.  But, the same technique works for any output power measurement.