Joule Thief

[Pirate88179]

@ freepow:

Maybe try raising the freq. as leds seem to like to light on high freq. with little or no power.  Anyway, that has been my experience.  I have lit 400 leds on a single AA battery.

Bill

[freepow]

 @ Pirate88179

How Do I raise the freq.

I am using a 1k variable resistor, it works brightest at almost lowest setting !

Also were your 400 LED's all at their brightest???

[Pirate88179]

The freq. depends on many variables, a lot of which I do not fully understand.  Core permeability, wire dia. number of turns, transistor specs, etc.  My 400 leds were as bright as if I plugged then into the wall for which they were designed.  I do not know exactly what freq. my jt was operating at but probably somewhere around 30 khz or so give or take.  Many others have exceeded what I have done so it might be interesting to see what freqs they were working at.


Bill

[freepow]

Sorry for all these questions but are those 400 of yours xmas lights?
are they those 20,000mcd LED's (which are blinding bright) ?
my 20x in the bulb are blinding bright

[Pirate88179]

@ freepow:

Hey, questions are fine.  They were Christmas light stings of 100 leds each times 4.  No, they were not ultrabright leds but 5mm "regular" led light bulbs.  They were designed to run from 120 volt grid power and I was amazed that I could light them all from a single AA battery and later, my EER (earth battery) outside.

I could have never done any of this without using what I have learned here on this forum.  Hopefully, I can beat this later with additional experiments.  If not, someone else will.

Bill