BUILDING A 'GRAVITY FIELD' COIL

[kampen]

Simulation: see attachment

Here's an "optimal" operating point for your Circular Electromagnet with gap
based on the geometry you described and the goal of keeping both Bloch walls active while driving a strong loop:

Best balanced high-energy point (from the sweep)
Turns (N): 300
Current (I): 5.0 A
Core μr (effective): ~500 (powdered iron / nanocrystalline-ish)
Gap (g): ≈ 1.37 mm
Flux density (core): ≈ 0.78 T (kept under an 0.8 T limit for this μr class)
Balance index (β = MMF_gap / MMF_core): ≈ 1.14 (nearly symmetric—both "walls" present)
Gap energy density proxy: ≈ 241 kJ/m³ (strong "looping speed/strength")

Why this point?
It sits just below saturation, maximizing field without crossing the knee.
β ~ 1 means the Secondary (gap) wall and Primary wall share the MMF burden—exactly your requirement to keep both walls simultaneously "alive."
Using μr ≈ 500 gives you a robust, low-loss core that tolerates ~0.8 T (powdered iron/nanocrystalline effective μ), which is hard to do with ferrite (would saturate sooner).

What to build here the recommended specs:
Core: Powdered-iron or nanocrystalline stack shaped as a ring (mean dia ~180 mm), effective cross-section ≈ (0.6×35 mm)².
Winding: N = 300 turns, copper that can carry 5 A continuous (or use parallel/li
Gap adjuster: Micrometer screw or shim system with 0.1–2.0 mm range; target ~1.4 mm for "balanced" mode.
Drive: Short trapezoidal nudges (10–50 kHz), duty ~60–70%, flyback capture on falling edges.

[kampen]

Simulation: see attachment
Here's a first-cut model that captures the tuning behavior you described
gap-controlled balance between the two "walls"
using a simple magnetic-circuit sweep.

It's not full FEM, but it's good for intuition and for picking starting dimensions.

[Ufopolitics]

Hello Kampen,

Thanks!, great job!!

And what is your conclusion, based on your simulation?

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Now, I have some questions/suggestions on other future simulations...

I see you have a max currents of 5A, but what about Voltage?...and wire gauge and total resistance used on those 300 turns of Coil?

Because, like I have mentioned before...a Coil which requires (based on its Total Resistance and Number of Turns), say 5 Amps, but only driven by 2.0- 5.0 Volts, will result on a very weak - and expensive, as consumption goes- magnetic field.

The stronger Magnetic Fields seat at much higher Voltage than Amperage ratio, like 120V and (less than) >2.0 Amps (used on Generators Exciting Fields)...or 12V and 0.5A...

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On another note, I would like to establish Simulation differences (if there are any) between a Straight, Cylindrical Coil versus a Circular one, like I am showing, and you are showing on simulation, basically relating to Consumption/Input.
And of course BOTH Coils having exactly, the same spec's, or same number of turns, same wire gauge, same resistance, as same Input relating to Voltage and Amperage (or Watts).
Except, a straight Cylindrical Coil will not have any 'Air Gap'.

So, please, could you do this same test-simulation but, on the same but straight coil for comparisons?

Thanks much!!

Regards

Ufopolitics