Joule Thief

[Mk1]

@ stprue

When I increased the pickup coil turns on the 3.38" toroid from 20 to 80 the frequency and output voltage each doubled.

I am not comfortable with that explanation , i believe it only changed freq because of the pickup coil location it is now picking up the pulses from both jt coil doubling the freq , there is a easy test to prove my point , make a 20 turn pickup coil and put it between the jt coil but closer then on your  20 turn pickup coil was when tested ...

Mark

[resonanceman]

If I were to rectify the secondary and feed it back in, I would blow the transistor.

Jeanna

I  guess it depends on how   you do it.

I have been  connecting   feedback   to the cap  in my Jesus charger
The only transistors I have blown  were  when I  was using the MOT JT


gary

[xee2]

@ Mk1

I am not comfortable with that explanation , i believe it only changed freq because of the pickup coil location it is now picking up the pulses from both jt coil doubling the freq , there is a easy test to prove my point , make a 20 turn pickup coil and put it between the jt coil but closer then on your  20 turn pickup coil was when tested ...

Mark

I do not understnad how you reached that conclusion. Attached are photos of the coils used for the tests. My experience is that the location of the coils does not effect results. But I do not have ascope. Jeanna says she sees a difference on the scope. I hope someone with a scope can document the effect you are talking about.

[Mk1]

@xee2

The location and also the direction of winding makes a difference , I tested all of them and there are different , i figured it out while looking for dead spot , by making a single loop around the toroid and moved it around the toroid , then do the same with a 5 turn one , you will see ...

Mark

Not seeing something doesn't mean its not there ...

And don't get me wrong here your input and work is important here and keep it up .

[jeanna]

@xee2,
I have some more data. I took pics of the big toroid core and the scope as I unwound the MK1 pickup and rewound it to solenoid style. 20 turns

Then since I had more wire, I wound as much as I could to 27 turns and took some more measurements.

I will now get the scope shots in a presentable form and be back.

I did light a neon with 27 turns and 224v. It was a little temperamental and maybe needed another finger on the bulb to start it, but maybe not. I took closeups of that and I hope I will be able to see.

I will be back to finish this report.

jeanna