Confirmation of OU devices and claims

[itsu]

Itsu good craftmanship!
As this experiment is using a [almost] square  wave input we can first estimate roughly a minimum of 15 -20 percent loss [ see your Spectrum Analyze ] only depending of wasted overtone energy that will never be sucked into the secondary coils if I'm right. The Secondary coils are only tuned to one tone, the first (over)tone.
To check if I'm right. Pls. make a spectrum reading at the point before the diode bridge. But without the diode bridge and with a 50 Ohm load.  Strong first tone and weak (no) overtones.
If you see strong overtones there with similarity to  the primary emission, then I'm wrong. Not enough filtering! Maybe good in your eyes.
See also my previous impedanse matching suggestions.
If you are able, make some efficiency tests with 3, 4, 5 sec. coils to see and evaluate, predikt if a much greater number of secoday coils maybe will improve the effectiveness.
In my eyes the main issues here are impedanse matching, the primary wave form and LED:s  .
If you still belive that the sharp square waveform is a must for the best result then the secondarys have to be constructed in a different way so they are able to take on, suck up All harmonics. Of course only valid if I'm right. Good filtering now.

Regards Arne

I modified one of the RX coils by removing the FWBR and buffer cap so we have the LC circuit and a 51 Ohm load resistor.

The Spectrum analyzer was across this 51 Ohm load and still shows the harmonics present across this RX series LC, but way less then what the TX coil transmits

So it seems the RX coils also partly absorb that harmonic energy radiated by the TX coil and thus all is not lost.


Itsu

[AlienGrey]

That article specifically addresses iron core transformers hence Ferro-resonance. Here we are talking about air core transformers which do not exhibit this effect.

Ferro-resonance is typically used in transformers to provide a degree of voltage regulation. (CVTs)

A slightly higher Q might be obtained if ferrite rods, Litz wire and low dissipation factor capacitors such as vacuum or mica types were used. The ferrite rods would allow fewer turns for the same inductance, thus cutting down on copper resistive losses. Nevertheless, the power coupling would still be less than 100%. The efficacy of the improvement would depend on frequency as ferrites also get lossy at higher frequencies so there would be an optimum frequency point where benefit could be achieved for a given ferrite material type.

Alternately the air core coils could be made of silver plated thin wall copper tubing as used in radio transmitters to keep losses low and Q high. Still, it will be less than 100% power transfer.

Regards

Err! don't be so quick to judge as that might be considered misleading information Mr. Vortex! as in the first section, that same none linear tactic is actually used in air spaced coils and works should anyone care to try it best results could be a pancake type coil or a tuned tank coil assembly.

[Vortex1]

Err! don't be so quick to judge as that might be considered misleading information Mr. Vortex! as in the first section, that same none linear tactic is actually used in air spaced coils and works should anyone care to try it best results could be a pancake type coil or a tuned tank coil assembly.

OK, I'm willing to learn AG. How do  I make a non-linear air coil? Kindly show me the BH curves or any other data showing results of your non-linear air coil as I would like to make one and test it myself.

Kind Regards

[seaad]

I modified one of the RX coils by removing the FWBR and buffer cap so we have the LC circuit and a 51 Ohm load resistor.
The Spectrum analyzer was across this 51 Ohm load and still shows the harmonics present across this RX series LC, but way less then what the TX coil transmits

So it seems the RX coils also partly absorb that harmonic energy radiated by the TX coil and thus all is not lost.

Itsu

Thanks Itsu for making the test.

This is my interpretation of the test result.

In your first Tx spectrum test:   The Tx radiated overtones are about 18 dBm below the ground-tone.   => Our incoming spectrum going to the Rx coil(s).
But now the Rx test gives :       The Tx radiated overtones are about 68 dBm below the ground-tone.

That differense 69 - 18 = 50 dBm  is One-hundred-thousen times less in power.
That means that the Rx LC(R)-filter filters avay, rejects practically all the transmitted   overtone power  from the Tx coil.
So power from the overtones goes up in "smoke" and partly becomes extremely small.

So now is the question how to solve that dilemma?

Regards Arne

[itsu]

Hi Arne,

you are absolutly right, the difference is hugh and the word partly is the wrong word.

Yes, the question is if that power lost in harmonics is affordable compared to f.i. using a sine wave as input.
If a sine wave does not produce any magic and the square wave does, then the choice is obvious.

But up till now no magic is seen at all.

Itsu