Joule Thief

[Mk1]

@paul

You should listen , to what we are saying , since it seems impossible , maybe make a regular basic joule thief ,first, and if you really can't go 5 pages , what are we to do post the schematic every page ?

The only hard thing about it seems to get you to get it.

Make one !

Hard ? can't go 5 pages back , lol ...

[jeanna]

Technically, the two connected windings are not a center-tapped winding. They are wound bifilar, and connected in series-adding. They are in effect two primaries connected in series, and the output winding is a secondary driving the LED.

A center-tapped winding or transformer is one continuous winding that has a tap somewhere along its travel. This is quite different than what we have here on the JT.

.99

The reason it is centertapped is because the place where they are joined  is connected to the positive of the battery.
If you connect the other (free) ends to the battery terminals it would be in series.

another way to say it is:
the direction of the turns is opposite on this and that is what is making it oscillate.
You can try all day long but if you make them this way it will oscillate, and if you don't it won't.

thank you,

jeanna

[PaulLowrance]

Okay Gadget,

Attacked is the latest. Any corrections? I want to get this exact! As you say, everything must be exact.     I'm sure there are more corrections for my circuit drawing.

Thanks,
Paul

[broli]

Lol. I really hope you attached the wrong one.

[gadgetmall]

Technically, the two connected windings are not a center-tapped winding. They are wound bifilar, and connected in series-adding. They are in effect two primaries connected in series, and the output winding is a secondary driving the LED.

A center-tapped winding or transformer is one continuous winding that has a tap somewhere along its travel. This is quite different than what we have here on the JT.

I think you would find that the circuit would work equally well if the three windings were put on separately, and the two which are connected could be done so as a true center-tap. The coupling due to the core is quite good I imagine, so it probably makes little difference how the windings are put on.

.99

really i is center tapped . another way to wind this is take one wire wind 6 turns pull a loop then wind 5 more same thing . when you wind two wires two wires together you have two that you started with and two at the end . you have to ohm out one of the first two wires and connect it to the opposite wire on the end side . I hope this makes since . and again maybe not . I might be an alien and cant communicate with people 

gadget