We have read the patent and at first glance don't buy the discussion & claims.
First off, the incremental inductance is proportional to conductor length, and then the outer turns contribute more inductance than the inner turns. The coil supports the applied voltage (assumed AC here), thus the outer turns with have a larger voltage drop than the inner turns with the sum equal to the applied voltage. This will cause the voltage difference between turns to be non-uniform and larger on the outer turns and smaller on the inner turns, this alone seems to violate the patent discussion starting at ~85.
Secondly, hopefully the coil isn't an "Over Unity Device", so storing more than "250,000" times as much energy would imply that a simple 1H coil with applied 100VAC, assuming 60Hz, would conduct 265ma and store 0.035 Joules, so this "specially wound" coil would store 250,000 times as much energy as a conventional coil, or 8,795 Joules!!!
We must remember that inductive coil energy is E = (L*I^2)/2, and this implies a coil inductance of 250,000 times increase, or 250,000H that's just not going to happen!!!
Applying EM analysis to the coil described in patent 512,340 and one should find some interesting characteristics, one of which it doesn't store 250,000 times as much energy as a conventional coil!! For simplicity think of the incremental inductance per coil turn and calculate the incremental stored energy per turn, as the sum total should be equal to (Leff I^2)/2 where Leff is the total incremental inductances summed over the whole coil.
Also from First off above, the incremental inductance concept is utilized in special wide-band RF coils commonly used a chokes where the coil is wound in a cone shaped spiral. This unique shape gives a much wider inductance range over frequency than a simple solenoid or flat spiral type coil. A little EM analysis will show such.
You could easily construct a small coil for physical measurements. Please be careful as if we are wrong one could easily kill themselves!!
Good luck on your intellectual endeavors!!
Best,
That's great. And, yes, cone shaped templates have also been fabricated for this project - for better testing options. However, the reason I went to the NanoVNA Custom Software Thread - was to get opinions on how this coil could be measured and interpreted correctly with a VNA. I will offer the questions & information I posed on another forum below:
This information & set of questions is for anyone who might be able to consider this scenario.
I am attempting to measure & understand the S11 and S12 characteristics of an interleaved, self-resonant, helical coil (not an antenna).
The wire will be wrapped on a 1-inch diameter tube.
An interleaved coil is also considered expired patent #512,340 - which claims self-resonance, inductance AND capacitance, and 250,000x the energy storage capability of a 1-wire coil.
https://patents.google.com/patent/US512340A/en I know the frequency that I want to put through the coil. Specifically, it is 1.387,114 Mhz - which translates to a wirelength of 216.2762 meters and real resistance of 73.231 ohms.
So, the coil will be made from 2 series-coupled lengths of 30 AWG copper magnet wire (each being 108.1381 meters long).
I can probably get close to the correct wirelength - since the coil length calculates to about 33 inches long.
1. The coil is made from 2 pieces of interleaved wire (not twisted pair)- meaning 2 wires that are adjacent to each other. Then the end of one wire is coupled at the opposite end of the other wire. It allows a signal to pass through the coil twice - but also creates a coaxial wire-type structure (which is what my questions relate to.)
The adjacent insulated pairs/windings will be snug up against (touching) the prior turns.
I am wrapping a helical version (and potentially a cone version) of patent 512,340 - not a pancake shape.
2. The copper wire is Essex brand 30 AWG copper magnet wire, with a 200 degree dual-poly enamel of some type.
Relative permittivity & velocity factor are currently unknown. I've contacted Essex to try to get velocity factor & relative permittivity information of the enamel, but have not heard back.
Insulation: Polyester w/ Polyamideimide Overcoat
NEMA Description: MW-35-C
Build: Heavy Min-Nom
Temperature Rating: 200°C (392°F)
3. AllAboutCircuits.com gives formulas for characteristic impedance & velocity factor - of both adjacent conductors and equivalent coax setups .
https://www.allaboutcircuits.com/textbook/alternating-current/chpt-14/characteristic-impedance/ 4. I have not yet equalized these 2 formulas - to find the relationship between 50 ohm coax & the impedance of the adjacent wire conductors.
It will also be useful to measure the actual length of wire ahead of time.
The bottom line is, however - I am trying to measure an interleaved coil - not a straight cable.
5. To make it easier - I could also test shorter 1/4-wave coils - such as an 8.3 inch wirelength (1.42 Ghz), or a 33 inch wirelength (355 Mhz).
6. Finally, my questions:
a. Firstly, does the NanoVNA normally show a resonant peak for coaxial cable - based on it's cable length resonance formula? (wirelength = 300 / frequency in Mhz).
Whether wound as coil or straight 2-wires - would the resonant point remain the same based on the wirelength?
b. Specifically, will the the results of the NanoVNA measurements distinguish the coil as a type of coaxial cable - since interleaved wires are defined as 2 adjacent wires separated by a dielectric? Or not?
I'm assuming the characteristic impedance of the interleaved coil won't be 50 ohms.
c. Conversely, would the measurement results from the NanoVNA be able to distinguish that the device is a coil? Or would the results look like a length of coaxial?
d. Would the NanoVNA also be able to give an accurate wirelength measurements for the interleaved coil - if the coil DOES somewhat behave as a coax cable?
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