Advanced PI coils

[Sergey_P]

3D math

target response or magnetic field Tx ?

[Davor]

Help me please. I have absolutely no idea, what you mean by that.
Aziz

I mean this one:

Ok, an IB case just calculated:
TX: 1 unit diameter, turns count any
RX+: 0.8*TX unit diameter, 50 turns
RX-: RX+/sqrt(2) unit diameter, 125 turns for IB (optimal for AI = 100 turns)

I'm interested how much improvement is there with outer coil being 0.8Tx. If unbalanced portion falls below 100mV - this is it! It would provide over 40dB suppression either way. And besides, if inner coil is made squeezable, I can obtain perfect balance in a jiffy - just about the easiest thing to make of them all.

...

@Sergey_P, please observe Aziz' avatar that's made with his software. It is very realistic.

[Sergey_P]

Aziz' avatar

beautiful, but useless...

[Davor]

On the contrary, it is only a presentation of very precise vector math behind. A picture by itself is just a nice presentation. If you ever need some very accurate simulation of a real thing, just ask Aziz politely.

I had some brief encounters with femm, and it was a pain. Aziz rules!

[Aziz]

target response or magnetic field Tx ?

Well, I can calculate much more:
- Inductivity
- Magnetic Flux
- Induction
- Self induction
- mag. field strength/density
- Coil couplings
- Induction balancing
- Parameter sweeps (for optimisation)
- Target related responses
- Sensitivity maps
.. and more

The reason, why I don't give/sell the coil software?
Avoiding anyone (particularly the patent-trolls) patenting good coil ideas, found/calculated by my software. I can guarantee, that these ideas will be published in the public domain.

If you plan something to patent, don't ask me doing anything for it/you. Keep it totally secret from me. But if I'm getting interested in it by mentioning an early idea, I very likely will work on it and if there is something valuable, I'll immediately publish the idea before you can write the patent application.

The "MadLabs Inc."(c)(r)(tm) isn't interested in patenting anything or making profits. I own 42 billion shares of "Madlabs Inc."(c)(r)(tm). I'm scheiss rich!!!

Aziz

[Aziz]

Avatar picture

I've found my bigger avatar picture finally ... *LOL*
Note, there is a smaller coil in it:


I'm lazy to change it. I'll keep it.
Aziz

[Sergey_P]

Aziz

Biot-Savart-Laplace ... without field objectives...

[Aziz]

Biot-Savart-Laplace ... without field objectives...

Yes, Biot-Savart, Maxwell equations, Faraday's Law.
Aziz

[Aziz]

I mean this one:


I'm interested how much improvement is there with outer coil being 0.8Tx. If unbalanced portion falls below 100mV - this is it! It would provide over 40dB suppression either way. And besides, if inner coil is made squeezable, I can obtain perfect balance in a jiffy - just about the easiest thing to make of them all.

...

@Sergey_P, please observe Aziz' avatar that's made with his software. It is very realistic.

The results were already on the 0.8TX unit size for RX+. RX- being RX+/sqrt(2) (=0.8TX/sqrt(2)) unit size. No chance to make the coil performing well for both AI + IB conditions at the same time.

Aziz

[Davor]

Yes, you said:

If we slightly make the inner RX- coil bigger, we could achieve the IB balance + AI feature.

yet I wish to know how much exactly. In case it breaks the 40dB barrier - I'm very happy.

[Aziz]

Yes, you said:yet I wish to know how much exactly. In case it breaks the 40dB barrier - I'm very happy.

Yes I know. This was a wrong assumption however. But it isn't possible to achieve both features.

You can't get even a 40 dB rejection with perfect AI coils. 20-30 dB is possible.
Aziz

[Davor]

OK. So my 4 quadrant Rx is back in race.

[Sergey_P]

Maxwell equations, Faraday's Law

you have a unified theory of the formation of the secondary induction field ?
Very interesting!

[Aziz]

you have a unified theory of the formation of the secondary induction field ?
Very interesting!

No, I have not. (Or should I apply for the Nobel prize? )
KISS-principle, Divide & Conquer, approximation

Following links might help you:
http://en.wikipedia.org/wiki/Biot%E2%80%93Savart_law
http://en.wikipedia.org/wiki/Faraday...w_of_induction
https://en.wikipedia.org/wiki/Amp%E8re's_circuital_law
http://en.wikipedia.org/wiki/Magnetic_flux
http://en.wikipedia.org/wiki/Maxwell's_equations
... see further links there

Heavy but trivial math. BTW, I hate math (that's my other bipolar disorder brain)! *LOL*

Cheers,
Aziz

[Davor]

I think I cracked the Davor-Sergey coil - solution is a Tx boosting coil. It would "homogenise" Tx field. So actually ppodg was right, only I did not think of the boosting variant at that time and I unjustly dismissed the idea.

Another approach: let's add a compensatig/decompensating tx or rx coil...

@Aziz, could you be bothered to run a test as in the example above with:
RX+ N=50, RX- N=100
TX: 300 µH at Rx+ radius, Tx boost 19 µH at Rx- radius, 1A coil current, f=10 kHz

Perhaps it would be interesting to see Tx field as well