Finding the LL resonant frequency

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cd_sharp posted this 3 weeks ago

Hi, everyone! As Chris suggested, I start this thread to try to reproduce the effects he obtained using this circuit:

My purpose is to find the conditions for this to happen:

where the top trace is input voltage, second trace is current through L2 and yellow is current through L1.

My setup is this:

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cd_sharp posted this 3 weeks ago

Partnered coils are on the same bobbin, spaced by a few millimeters, one CW and the other CCW.

Both are 43.6 mH, 1 Ohm, 0.6 millimeters copper wire. Because the bobbin is custom made the 2 coils are not that symmetrical like the ones Chris has used:

I believe it's not important that the two coils to be strictly symmetrical since they have the same inductance, resistance, length and core. Chris, please let me know if I'm wrong!

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cd_sharp posted this 3 weeks ago

Around 300 Hz I noticed the 2 phases that Chris talked about, the Storage and Decay on the current through L1 (yellow trace):

However, I did some fast sweeping all the way up to 150 KHz and I could see no phase drift. The current through L2 (blue trace) flows always during the Storage phase.

It could be that I'll need to sweep more carefully, using a step value of 0.01 Hz, but this requires a lot of time. Work in progress..

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cd_sharp posted this 3 weeks ago

My mistake, I connected L2 the other way around. As soon as I switched it I start getting some interesting results:

And the interval is not narrow at all, it starts at about 180Hz input frequency.

First idea that comes to mind is that I should make both coils bigger to make the EM induction dominate.

Chris posted this 3 weeks ago

Hey CD,

I wish I could give you 10 thumbs up! Fantastic Work!

To experiment here gives huge insight how Coils interact together! Some combinations work well, others not so well.

The sharp peaks seen in your post, appear to be where the Core is going into Saturation. Just thought I would point this out.

This is fantastic to see! I am so pleased that you are observing this very important phenomena! I guess you would agree that there is a massive amount of data to be learned from in these experiments?

Where the Current's are, in relation to the turns direction and placed where in Time ( t ) is a very beneficial in understanding this phenomena!. Keep experimenting and keep learning, there are great roads ahead!

Fantastic Work!

   Chris

P.S: Do you see a relation to Akula's 30 Watt Lantern here?

Vidura posted this 3 weeks ago

Hi CD Very important this experiments, I'm following further measurement. May I suggest to make a test with soft iron or niquel alloy as core material, to see influence of permeability.

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Chris posted this 3 weeks ago

Hey Guys,

I should mention, when I have said Currents Equal and Opposite, be carefull of the Turns and the Timing of the Circuit.

Often what appears on the scope, may be completely different from what you may expect! As an example:

 

 

The above image has a 31% On time, seen partly on the Red Trace Zero Graticle Line, all the rest is off time. None of the Currents are inverted! 

Take special note of the very large Negative Current on the Yellow Trace! It almost appears as if the Current on the Yellow Trace is moving backward in Time ( t ).

These currents were only supplied from a 400 ma supply, the total on the scope is: 1152.7 Amperes. 

So take your time and study carefully!

   Chris

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cd_sharp posted this 3 weeks ago

Hi, guys!

The sharp peaks seen in your post, appear to be where the Core is going into Saturation.

It's very good to know that.

Where the Current's are, in relation to the turns direction and placed where in Time ( t ) is a very beneficial in understanding this phenomena!

They follow the right-hand rule, but only on the Decay phase. That was my initial mistake.

Do you see a relation to Akula's 30 Watt Lantern here?

Yes. For instance, if I reduce the DTC until around 20%, the current through L2 keeps flowing. Very similar to the Akula lantern.

May I suggest to make a test with soft iron or niquel alloy as core material, to see influence of permeability

I'll try once I did a complete set of experiments. Thanks for the suggestion.

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cd_sharp posted this 3 weeks ago

Is this obtained using the same exact circuit?

It almost appears as if the Current on the Yellow Trace is moving backward in Time ( t )

The so called "time-reversed wave" that nobody knew what it means except Bearden.

These currents were only supplied from a 400 ma supply, the total on the scope is: 1152.7 Amperes.

Awesome results. Thanks for sharing, Chris!

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Chris posted this 3 weeks ago

Hey CD,

A slightly different Circuit, Akula style. I can see, that you can see whats going on here now!

I am so happy that others are picking up the ball and running!

For others following, LL is Inductive ( L ) Inductive ( L ), basically this is where the Partnered Output Coils are showing Magnetic Resonance.

Great Work CD! I am very pleased your'e getting good results!

   Chris

 

P.S: My Sharp Peaks, also i am saturated at this point.

cd_sharp posted this 3 weeks ago

Hi, guys! Before I add some turns to my coils I thought I play with some ferrite magnets. This is the best result so far:

This is without the magnet:

And this is with the magnet attached near coil L1:

So, the magnet lowers the current through L1 and raises the current through L2. DTC is 33.1%.

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