Joule Thief

[jeanna]

@MK1,

I am having a really hard time with this MK1 I am making from a blue toroid.

You mentioned you were having a hard time with a blue toroid when making your MK3 yesterday.

Was it by any chance a blue toroid from electronic goldmine? part G16460 by any chance?

The light goes on then slowly dies out like something is taking its juice. I have to touch it to get it back on.

The circuit works fine with every other toroid. I just popped a few in to check if something just broke in the circuit, but the other toroids are fine all connections are fine etc.

I wound 30 pick ups 15 up then 15 down on each side. Then I thought that was too tight and took off a few. It seems to be down to 13 up and 13 down. Is that the right thing to do? Is that what you are doing when you are tuning this.

I was quite alarmed to see no light at all, then just a flaky flickery light after I removed a couple of secondaries. I even re-wound the bifilar just to make sure. But the circuit is on drawing 30 mA without the light, but the light is only a temporary glimmer.

The sheep would not look good with this one!

Help? I mean is this the same blue one? Is taking off turns the way you do it?

jeanna

[nievesoliveras]

@all

Here is the way I think the @mk1 toroids are wound or winded. There are two.

@mk1
Which one of those two ways is the correct one?

Jesus

[TheNOP]

@nievesoliveras

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just like the jt coils

the reason the digits are reversed is that the coil is on the other side of the toroid.
kinda a mirror effect.
take a toroid, put a coil on it, then turn it 180 degrees, what do you see ?
what was on the right side is now on the left side.

all coils start to the left
turns are added going right of the start points
then back to start points over itself.

[jeanna]

@Jesus,

The MK1 has 2 windings on each side of the split bifilar winding. That is 4 wires all together.

1 piece of the bifilar on one side and opposite that the other.

Now, each pickup coil goes first up, then it returns down. So the start and finish of the pickup wire is in the same place.

This is what makes the MK series different from all other ways we have/ I have tried.

Go up then down.
Starting with a new wire and on the other side, go up then down.

I have to do something for a few minutes, but I will download your pic and draw over it. OK?

jeanna

[Mk1]

@jeanna

My blue Toroid is not from goldmine, but its useless i got four of them .

@jesus

Both should work , the second one is like 2 coils in one i would connect the battery positive lead to the middle of the toroid to make the 2 coils , but those coil are only on the jt side , and the toroid used will dictate the number of turns needed on the jt side.