cComega virtual coil

[WM6]

I had to implement the slow "brute force"-method, that computes the magnetic flux of the coil arrangement. This method is quite accurate and depends on the resolution (number of wire segments, delta, etc.) of the simulation. Capacitance of the coil is not implemented (much more work).

Aziz

Superb Aziz.
Here you are "brute force"- coil, that compensate total capacitance of coil and best suit your "brute force"-method.
Hurry up!

[WM6]

Could it be possible to reflect (deflect) all the "upward" field so it is only transmitted downside,in a similar principle of yagis antennas ? But as the dielcetric properties of the reflector would most probably be a problem , maybe an active device like in phased arrays?

After all, 50% of energy is lost in all those coils...

just a thought,
regards,
Fred.

Hi Fred. Good news.

There is possible to reflect or direct (dependent of winding direction) coil magnetic field downside to soil.

Solution of this problem is presented in Azizs avatar (insulated helical winding placed on coil as wire shielding, it has inductive, not galvanic, feed by coil and is connected in on one side to cable shielding - mean not self connected in circle).

Aziz application can give us graphical proof of this statement. One can test this by shielding experimental coil in such manner.

[Tinkerer]

Magnetic forces repelling

The two pictures attached show two coils with the current running in the same direction, that is the magnetic forces aiding, and with the current running in opposite direction, that is, magnetic forces repelling.

It is also possible to repel the magnetic forces with a Graphite disk, it needs to be seen how fast the eddy currents decay in the graphite disk.

Tinkerer

[Fred]

Hi,
Thanks for those infos.
Tinkerer´s views ar more like what i imagined,and it is nice to see there are more than one solutions.
regards,
Fred.

[WM6]

The two pictures attached show two coils with the current running in the same direction, that is the magnetic forces aiding, and with the current running in opposite direction, that is, magnetic forces repelling.

It is also possible to repel the magnetic forces with a Graphite disk, it needs to be seen how fast the eddy currents decay in the graphite disk.

Tinkerer

Hi Tinkerer, nice visualization. I can see deformation of field on your presentation of field distribution to one direction, but can not see any magnification in opposite direction, rather contrary. Decaying of eddy currents in graphite disk do not mean that graphite disk repel magnetic forces, this two statement are contradictory. Only opposite magnetic forces (in polarity and direction) can repel magnetic forces. According this only magnetic disk, can repel magnetic forces of one TX coil (better to say condense magnetic forces in same direction) . But repel not need to be a sign of magnification of magnetic field in opposite direction. Nevertheless, nice picture, thank you.

[Aziz]

Hi,
Thanks for those infos.
Tinkerer´s views ar more like what i imagined,and it is nice to see there are more than one solutions.
regards,
Fred.

It depends on the configuration: I got same results, if taken described configuration below. My respresentation is correct!
;-)

[Tinkerer]

Magnetic fields repel

It depends on the configuration: I got same results, if taken described configuration below. My respresentation is correct!
;-)

AZIZ,

your representation is indeed correct. In the visualization that I presented above, (It was produced by my friends at MIT), the top coil has one third of the current of the bottom coil.
In your visualization you have reduced the amount of turns of wire, but maintained equal current.
Since the field strength is Amps X Turns, the result is the same.
Congratulations to your software.
Tinkerer

[WM6]

It depends on the configuration: I got same results, if taken described configuration below. My respresentation is correct!
;-)

Congratulation! Sure, it is correct, but don't forget to ask what benefit of this configuration? Where is magnification in comparison to configuration of two coils with current flow in same direction? As I understood primary goal was to reach some directed magnification of M. field by reflective element. So reflection (better to say condensing) work, but where is magnification in opposite direction in comparison to same construction with same both currents but in same direction?

[Fred]

One interesting thing we can see on those pictures is that Aziz´s coil lobes are directed inwards and Tinkerer´s are outwards.
The first one is probably better, but this is surely easy to correct by varying the upper coil diameter.
For practical contruction the graphite disk coil must be simpler to build , as long as the disk remains thin and lightweight.

Regards,
Fred.

[Tinkerer]

Coil disposition

About the coil visualizations:

• The combined fields of the two coils change with increasing or decreasing distance.
• The magnetic fields do not cancel each other. They repel each other.
• If the visualization were to show the respective fields of each of the coils in different colors, the colors would be intermingled.
• If we place an RX coil within the combined field of the two coils, the currents that are generated within the RX coil will NULL, if the strength of the opposing fields that are cutting through the RX coil, are equal.

Below the real world coil. This is an actual IB coil that I built and that has given amazing results.

TX coil - outer dia. 275mm-inner dia. 220mm-27 Turns
RX coil -outer dia. 200mm-inner dia. 50mm-62 Turns
Buck coil-outer dia. 170mm-inner dia.110mm-27 Turns

TX and RX are on the same plane.
A polypropylene spacer of 8mm is placed on top of the TX and RX coils.
The PP spacer is coated with 50 microns of Graphite. A drain wire conducts the noise and eddy currents from the Graphite to Analog ground.
The Bucking coil is placed on top of the Graphite. A precise NULL is found by moving the Bucking coil slightly off center.

I wonder how the combined fields of this coil would look like?
Tinkerer

[Aziz]

Hi at all,

I was knocked out for several days due to my toothache. I lost two tooth.
Now working on the very interesting questions. First results can be expected to the beginning of next week.
So long,
Aziz

[WM6]

Hi at all,

I was knocked out for several days due to my toothache. I lost two tooth.
Now working on the very interesting questions. First results can be expected to the beginning of next week.
So long,
Aziz

Hi Aziz, why you do not use magnetic field as toothache pain relief?
As you can see on this link it is proven:

"The Norstar Micro Neo magnetic field is specifically designed for sinus problems, breathing problems, migraine, neck, hands and feet pains and toothache."

http://www.norstarbiomagnetics.co.uk...herapyNeos.htm

healthy wishes to you!

[Aziz]

Hi WM6,

Hi Aziz, why you do not use magnetic field as toothache pain relief?
As you can see on this link it is proven:

"The Norstar Micro Neo magnetic field is specifically designed for sinus problems, breathing problems, migraine, neck, hands and feet pains and toothache."

http://www.norstarbiomagnetics.co.uk...herapyNeos.htm

healthy wishes to you!

Thanks, I feel good now.
The reason is explained quick:
Due to eddy currents, induced in my tooth filling would heat up my tooth.
It isn't good idea.


Coil software is in good progress. Inductivity of (inductively) coupled coils is finished and tested. It computes even parallel / anti-parallel coil configurations correct. Inductivity can be computed on any arbitrary coil shape and impedance (no common formulas used). So I can design a better VLF coil for a particular market metal detector model.

Aziz

[Esteban]

Hi Esteban

Are they suggested which turn of RX coil we have to left free (first, last, twentieth ....?)

Thank you.

One of the extreme wires of receiver coil. Maybe this kind of adjustment (with a portion of free wire as a nulling coil) can be possible because transmitter has contact with receiver via 2 capacitors, one fix and other variable. This detector is type "audio up", this is, you note the target because audio level increases in hearphone or speaker. The characteristic of this omega coil (TX) and round receiver is this: you adjust the receiver coil for to leave out nails and wire of fences, for example, helping with variable trimmer and position of receiver coil only in one of the both zero adjustment. This both zero are very near. But you note nails and iron wire in this way: put a little audio with sensibility potentiometer (here is very most sensitive, because audio level is more clear). When you detect nails or iron wire, the small audio you hear in hearphones vanishes. This occurs also in mineralized soils with iron minerals. This leave out nails and iron wire, but not relic iron. This is great oscillator and receiver circuits. Is some difficult to adjust, but if you use good components (important capacitors), the oscillator stay quiet. The only problem can be the cold weather. Also emitter resistor is very important, better 1%, between 56 to 68 ohms. Transistor also is important here, gain 200-250, type BC547 A.

This is automodulated circuit. You can change audio tone if you replace the base capacitor.

Regards

Esteban

[WM6]

One of the extreme wires of receiver coil. Maybe this kind of adjustment (with a portion of free wire as a nulling coil) can be possible because transmitter has contact with receiver via 2 capacitors, one fix and other variable. This detector is type "audio up", this is, you note the target because audio level increases in hearphone or speaker. The characteristic of this omega coil (TX) and round receiver is this: you adjust the receiver coil for to leave out nails and wire of fences, for example, helping with variable trimmer and position of receiver coil only in one of the both zero adjustment. This both zero are very near. But you note nails and iron wire in this way: put a little audio with sensibility potentiometer (here is very most sensitive, because audio level is more clear). When you detect nails or iron wire, the small audio you hear in hearphones vanishes. This occurs also in mineralized soils with iron minerals. This leave out nails and iron wire, but not relic iron. This is great oscillator and receiver circuits. Is some difficult to adjust, but if you use good components (important capacitors), the oscillator stay quiet. The only problem can be the cold weather. Also emitter resistor is very important, better 1%, between 56 to 68 ohms. Transistor also is important here, gain 200-250, type BC547 A.

This is automodulated circuit. You can change audio tone if you replace the base capacitor.

Regards

Esteban

Thank you Esteban
Very informative.
Seems as one of multi-frequency stuff?
Thanks