Step 2: Wind the transformer

Picture of wind the transformer
this transformer is the crucial element to make joule thief work with lemon. it requires much more winding then in the normal joule thief design and only plain ferrite works - all colored rings failed.

1. take about 1.5-2 meters of copper wire, bend it in half and wind the coil with it. in this case it took around 50-60 windings arranged in two layers.

2. after the winding is done - cut the double end, so that you have 4 loose single tips.
3. clean the tips from the isolation lacquer with sanding paper
4. with a multimeter set on conductivity test, find two separate windings
5. twist two opposing ends of different windings into one contact
6. pre-solder the tips of the transformer.

your transformer is ready!
.A.2 years ago
This just gave me an idea. If it works i'll post an instructable.
rayfalcon4 years ago
so if i have a pre- wrapped torrid from an old computer monitor that has the plastic coating on it then i have to remove the coating before the joule thief or the transformer will do anything???
rottenmeat5 years ago
doesn't the coil just short because you stripped off the insulation?
something that most people dont know and it will help with the torroid after you have wrapped it especially if you dont use different color wires it can be really hard to tell what wires are going to be togather and which are not, take your meter and set it for continuity, test to see which ones short 0.00 then you know what goes to what, also dont forget most wire is insulated so you will need to remove it, before you can put any power through it. hope that helps I know my first toroid i couldnt figure out if it was right, power was only going to half (wrong legs wired up)