Very large DD coil

[Krzychu_]

I have already collected all the necessary materials: enamelled winding wire, extruded polystyrene foam, carbon fiber, graphite, epoxy resin with hardener, shielded cables, plugs, DC-DC converters and a router to cut grooves on the coil winding.

[Krzychu_]

Has anyone tried to use a program (eg ANSYS (?)) that allows you to easily simulate and estimate the location of TX transmit coils relative to the RX receiving coil depending on their geometry, the number of coils wound and currents and induced voltages to achieve induction balance in the real system?

Regards

[Krzychu_]

Today I cut in the plate of the soil under the winding of 5 transmitting coils, which will flood the epoxy resin

[kt315]

first mistake. you do not have to flood coils the epoxy resin.

[Krzychu_]

I know I do not have to, but it seems to me that the resin will give the coil additional stiffness, and the low weight of the coil is not so important. In addition, the resin mixed with the carbon fiber will become slightly conductive and will constitute an electrostatic screen [for the receiving coil only]. If you know a better solutions - hint, if it's not a secret.

[kt315]

wind round the winding by rope. take a wide one. take cheapest. paper or canvas done. may do several layers (of the rope). then
only wind around sticky scotch lenta, also several layers. after that put at the place and fill the epoxy resin.
you get the coils in air, not saturated by resin.

[Krzychu_]

OK, thanks for the advice. Did I understand correctly that enameled wire should be wrapped with a wide rope or tape? Is it because the coil so made does not transfer vibrations, tension and other unwanted effects from the resin to the windings?

[dbanner]

OK, thanks for the advice. Did I understand correctly that enameled wire should be wrapped with a wide rope or tape? Is it because the coil so made does not transfer vibrations, tension and other unwanted effects from the resin to the windings?

Yes, it is for isolation from vibration at a certain frequency being transferred to coil. The rope acts like shock absorber.

[dbanner]

I can't say for sure,but tiny movements across such a long axis is amplified, and could affect the coil.

[kt315]

Yes, it is for isolation from vibration at a certain frequency being transferred to coil. The rope acts like shock absorber.

not. not vibration. we say again about ε_r --- is the relative static permittivity (sometimes called the dielectric constant) of the material between the plates (for a vacuum, ε_r = 1);

look https://en.wikipedia.org/wiki/Capacitance

As a quantitative example consider the capacitance of a capacitor constructed of two parallel plates both of area A separated by a distance d. If d is sufficiently small with respect to the smallest chord of A, there holds, to a high level of accuracy:C=ε rε 0Ad{\displaystyle \ C=\varepsilon _{r}\varepsilon _{0}{\frac {A}{d}}}

[kt315]

see a table on right https://en.wikipedia.org/wiki/Relative_permittivity

look vacuum vs air RPs.

[Krzychu_]

Thanx!
I plan to make two RX windings on both sides of the TX transmit coil connected with antiparallel. This will be a simple system for verifying false signals from the coil excitation. I will consider single signals to be false, and double signals to be correct. Is it good idea?

[dbanner]

Then for capacitance issue, well ok, make sense. So you are not making big capacitance.
My shock absorber theory was rubbish then.

[kt315]

Kr_

we do not have the experts here on big ramified coils to say you more. no data. i can give some recommendations and thas all.
in my opinion you do not have to strengthen the windings in all constructive and have to test at first as temporary one.
after getting good result then gather them and glue together.

[Krzychu_]

OK, I intend to finish the transmission winding and pour it over the resin without electrostatic shielding, while the RX receiving winding pre-position and check the correctness of identification and discrimination. It's hard to predict the effect of the electrostatic screen on their final, mutual location. When balancing the coils, I will have to leave part of the loose section of the windings to correct their compensation