Joule Thief Toroid not helping to step up, Why?

Hey fellas..I am having problems with joule thieves especially with the toroid part.... First time I wound my Ferrite Core and the joule thief ran smoothly... But recently I had to unwind it to try other wires which didn't work.. So i again wound up the toroid just like the first time when it used to work but unfortunately this time it didn't work... I have checked everything and found that the only problem is that the toroid is not helping to step up the voltage.. When i applied 9V across it, the LED glowed but for 1.5V it didn't. So there is a problem with the toroid.. But what it is and why is it happening I don't know..I mean for the same core and same style of winding once it worked and now it doesn't, Why ?? Can anyone help me ??

iceng3 years ago

Are they wired like this?

Are you using insulated or magnet wire ?

Arijit Chatterjee (author) 3 years ago

I got the answer... I searched a while on net and found that we have to sort the wires of different coil and that too in opposite direction (That was the mistake i made). I used to sort the wires of the different coils on the same direction.. Later found that if I use one wire of upper side then it has to be sorted with the wire of second coil from lower side... It is running smoothly again... Thanks steve and iceng....

What makes you think you haven't damaged the transistor?