Advanced PI coils

[Aziz]

Unfortunately, the idea failed right now. The coil gets thicker (now 30 mm at least).
Compensation coil is required to make it thinner. I'll try more ideas ..
Aziz

No, the above were the best I could get. All other trials produce a lot of zero's (super insensitive).

Anyone with a good idea?
Aziz

[Aziz]

Yes, I'm very curious about the outcome. In such configuration Rx coils would both be far apart from Tx so even the capacitive couplings will not make any influence - no Cx and all.

Unfortunately, the idea failed right now. The coil gets thicker (now 30 mm at least).
Compensation coil is required to make it thinner. I'll try more ideas ..
Aziz

[Davor]

Yes, I'm very curious about the outcome. In such configuration Rx coils would both be far apart from Tx so even the capacitive couplings will not make any influence - no Cx and all.

[Aziz]

Hi all,

hey, I've survived the doomsday.
(To your bad fortune, you have to bear with me and my coil sims now. )

--------------------- serious mode ------------------------

Ok, let's modify the Davor-Sergey coil a bit to decrease the ground noise (magnetic viscosity effects etc.) and make it a bit thinner (co-axial thickness). That could be made, If we're going to make the RX- smaller (0.8 ) and RX+ accordingly 0.5RX- (0.4). Note: No compensation coil (CX) favoured.
Let's see, what comes out... and whether an IB condition can be made too..
Aziz

[Aziz]

Hi all, .. .. oh sh1t!, the doomsday is coming .. the doomsday is coming...
I'm going to a34j´405lkjfg982756uldfkgiz$§"%§asdf540^72j$%§$&"§ &!&!%&"§$!§$....

<error>

<beep>

<connection lost>

<beep>

The current universe has been crashed.
Please enter '[B]42[/B]' to restart the universe.
41
Syntax error!
Please enter '[B]42[/B]' to restart the universe.
42
Reset
Restarting the universe now ..
Loading the world V2.0 ..
Loading .. please wait..
..............................
..............................
......
Done.
Aziz: Hello World! 
Aziz: This is Aziz V2.0. 
Aziz: Are you Ok?
Aziz: Hello? Hellooooooo! Is anybody there????

Soo funny. Sorry, but I couldn't resist..

[Aziz]

The Davor-Sergey AI IB Coil vs. Mono Coil

This is the coil configuration above compared against a mono coil. I didn't make the coil configuration with the compensation coil (CX) and we can neglect it as it won't do much better. The following figures give you the performance comparision regards to mono coil and SNR. You can see, that the target response losses are significant at depth. But the EMI noise rejection should be good as the RX+ and RX- coils won't be much apart and you can ramp up the gain with a low noise amplifier to compesate for losses. Notice, this is an IB and AI coil.

Coil Comparison (Calculated Response Ratio to Reference Coil)
© 2012 by Aziz Ögüt. All Rights Reserved. 20-Dec-2012
Reference Coil: 300 µH Round Mono Loop Coil
		10" Davor-Sergey AI IB Coil (0.71RX)	10" Davor-Sergey AI IB Coil (0.5RX)
Target Depth [inch]	Target Depth [cm]	Relation to Reference	Relation to Reference
1	2,5	1,759	5,895
2	5,1	1,475	3,924
3	7,6	1,165	2,540
4	10,2	0,916	1,736
5	12,7	0,733	1,266
6	15,2	0,601	0,974
7	17,8	0,503	0,781
8	20,3	0,430	0,648
9	22,9	0,373	0,550
10	25,4	0,329	0,476
11	27,9	0,293	0,419
12	30,5	0,263	0,373
13	33,0	0,239	0,336
14	35,6	0,219	0,305
15	38,1	0,201	0,279
16	40,6	0,186	0,257
17	43,2	0,173	0,238
18	45,7	0,161	0,222
19	48,3	0,151	0,207
20	50,8	0,142	0,195
21	53,3	0,134	0,183
22	55,9	0,127	0,173
23	58,4	0,121	0,164
24	61,0	0,115	0,156
25	63,5	0,109	0,148
26	66,0	0,104	0,141
27	68,6	0,100	0,135
28	71,1	0,096	0,129
29	73,7	0,092	0,124
30	76,2	0,088	0,119

Cheers,
Aziz

[Aziz]

The Davor-Sergey AI IB Coil (without CX)

Hi all,

this coil configuration inductively balances by setting the RX- coil apart from the co-planar region slightly (~20 mm).
I think, it won't disturb the coil architecture when it is slightly thicker due to coil arrangement. But it makes the coil design a bit simpler and easier to balance (two options - see below). The picture below is showing the RX+ radius factor of 1/sqrt(2) in an induction balanced state.

The 0.5 radius factor is getting slightly thicker. The co-axial balance distance is almost an inch wide (actually 25 mm in my model). But it performs a bit better of course.

I'll make the comparision for 0.71RX and 0.5RX and will add the compensation coil variant too (the CX coil part). If you see the CX naming, then you know, you need additionally the CX coil (which makes the coil more complex of course).



Isn't that fine, that you don't need a CX coil?

Cheers,
Aziz

[Aziz]

Great work, congratulations and many thanks.

How do you feel about the TANDEM COIL? Basically 2 concentric, coplanar IB coil assemblies side by side, in opposite phase. This should be good for AI as well as GB, if the signals of the 2 coil assemblies are processed as differential. Like a gradiometer.

You're welcome Tinkerer. All the calculated performance comparison figures are my Christmas gift to you all.

Tandem coil is also interesting. I'm thinking of coding my coil software to make few things more comfortable to me (less work). So I can make the figure-8 coil analysis as well.

All the trivial work first of course.

Cheers,
Aziz

--------------------------------------------------------------------------
PS to patent-trolls:
No! No! Don't do it! Don't do it bad guy! I'm going to **** you otherwise...

[Tinkerer]

What's left over? I have made almost 3 dozens of coil simulations and I'm stil not finished yet.
The other coils will be added from time to time until the doomsday is stopping me doing this.

Ok, the co-axial stacked AI mono coil (the Eric Foster's coil in this thread), where the TX=RX+ (after switch-off) and above the RX- coil is placed coming soon.
The Davor-Sergey coil, ... coming soon too.

Cheers,
Aziz,
I'm so tired...

Great work, congratulations and many thanks.

How do you feel about the TANDEM COIL? Basically 2 concentric, coplanar IB coil assemblies side by side, in opposite phase. This should be good for AI as well as GB, if the signals of the 2 coil assemblies are processed as differential. Like a gradiometer.

[Aziz]

Bl00dy hell!!!,

I'm going to beat all VLF detectors...
It's quite difficult to make some bench testing with the loose coil assembly at the moment. But as far as I could see the detection depth on a 1 EUR coin, ... and it's sensitivity to small targets ...

I have used the center-tapped Tophat TX coil drive (=high power VLF) with an active RX amplifier this time.

I need a stable coil frame assembly.
I need a stable coil frame assembly.
I need a stable coil frame assembly.

It's time to make new world records...

Aziz

Hi all,

do you remember my posting above?

The calculated results and the observed real coil testing results confirms this. I have a vey sharp pin-pointing feature. And there is a higher sensitivity in the near detection zone too so I can detect small targets as well to a remarkable detection depth. And it goes deeeeeeeeeeeeeeeep, which I'm capable of to beat all the VLF detectors...
Ooooooops, probably not anymore. Damn it!, I shouldn't have published the results... Everybody can beat the existing metal detectors now.


I'm not finished yet.. stay tuned...
Aziz

[Aziz]

Mono AI PI Coil vs. Mono PI Coil

Hi all,

this is the co-axial stacked mono PI AI coil comparing it against the mono coil. The standard mono coil acts as the RX+ coil part after switch-off. Co-axial above (5, 7.1, and 10 inch) there is the RX- coil for the anti-interference feature. This is the Eric Foster's AI coil shown earlier.

Coil Comparison (Calculated Response Ratio to Reference Coil)
© 2012 by Aziz Ögüt. All Rights Reserved. 20-Dec-2012
Reference Coil: 300 µH Round Mono Loop Coil
		10" Mono Co-axial AI PI Coil (5 inch distance)	10" Mono Co-axial AI PI Coil (7.1 inch distance)	10" Mono Co-axial AI PI Coil (10 inch distance)
Target Depth [inch]	Target Depth [cm]	Relation to Reference	Relation to Reference	Relation to Reference
1	2,5	0,712	0,834	0,913
2	5,1	0,753	0,857	0,926
3	7,6	0,763	0,859	0,925
4	10,2	0,759	0,853	0,919
5	12,7	0,746	0,841	0,910
6	15,2	0,729	0,826	0,898
7	17,8	0,710	0,808	0,885
8	20,3	0,689	0,790	0,871
9	22,9	0,667	0,771	0,856
10	25,4	0,646	0,751	0,840
11	27,9	0,625	0,732	0,824
12	30,5	0,605	0,713	0,808
13	33,0	0,585	0,694	0,793
14	35,6	0,567	0,676	0,777
15	38,1	0,549	0,659	0,761
16	40,6	0,532	0,642	0,746
17	43,2	0,515	0,625	0,731
18	45,7	0,500	0,610	0,716
19	48,3	0,485	0,594	0,702
20	50,8	0,471	0,580	0,688
21	53,3	0,458	0,566	0,675
22	55,9	0,445	0,552	0,662
23	58,4	0,433	0,540	0,649
24	61,0	0,422	0,527	0,637
25	63,5	0,411	0,515	0,625
26	66,0	0,400	0,504	0,613
27	68,6	0,391	0,493	0,602
28	71,1	0,381	0,482	0,591
29	73,7	0,372	0,472	0,581
30	76,2	0,363	0,462	0,570

Cheers,
Aziz

[Aziz]

What's left over? I have made almost 3 dozens of coil simulations and I'm stil not finished yet.
The other coils will be added from time to time until the doomsday is stopping me doing this.

Ok, the co-axial stacked AI mono coil (the Eric Foster's coil in this thread), where the TX=RX+ (after switch-off) and above the RX- coil is placed coming soon.
The Davor-Sergey coil, ... coming soon too.

Cheers,
Aziz,
I'm so tired...

[Aziz]

TX/RX Anti-Interference PI Coil vs. Mono Loop Coil

This is the TX/RX (separate TX, RX) PI coil comparing against the mono coil. Note: This isn't an IB coil. It's a PI coil.
We have a 10 inch TX (300 µH), a smaller concentric co-planar RX+ coil and at 5 or 10 inch co-axial distance (above) a RX- coil for anti-interference feature. The radius factors for each smaller RX coils are either 0.71, 0.5 (half) or 0.33.

In the earlier post, there is the standard version of these coils (but not AI).

Coil Comparison (Calculated Response Ratio to Reference Coil)
© 2012 by Aziz Ögüt. All Rights Reserved. 20-Dec-2012
Reference Coil: 300 µH Round Mono Loop Coil
		10" TX/RX AI PI Coil (0.71RX, 5 inch distance)	10" TX/RX AI PI Coil (0.71RX, 10 inch distance)	10" TX/RX AI PI Coil (0.5RX, 5 inch distance)	10" TX/RX AI PI Coil (0.5RX, 10 inch distance)	10" TX/RX AI PI Coil (0.33RX, 5 inch distance)	10" TX/RX AI PI Coil (0.33RX, 10 inch distance)
Target Depth [inch]	Target Depth [cm]	Relation to Reference	Relation to Reference	Relation to Reference	Relation to Reference	Relation to Reference	Relation to Reference
1	2,5	2,285	2,588	6,339	6,724	17,300	17,744
2	5,1	2,004	2,247	4,351	4,644	8,251	8,578
3	7,6	1,688	1,902	2,969	3,219	4,464	4,737
4	10,2	1,431	1,634	2,165	2,396	2,848	3,095
5	12,7	1,240	1,440	1,693	1,915	2,056	2,291
6	15,2	1,099	1,300	1,398	1,617	1,615	1,846
7	17,8	0,993	1,196	1,201	1,421	1,342	1,572
8	20,3	0,910	1,117	1,062	1,283	1,159	1,389
9	22,9	0,844	1,055	0,958	1,182	1,029	1,260
10	25,4	0,789	1,004	0,877	1,104	0,931	1,163
11	27,9	0,742	0,960	0,812	1,041	0,854	1,088
12	30,5	0,702	0,923	0,759	0,989	0,791	1,027
13	33,0	0,667	0,890	0,714	0,946	0,740	0,976
14	35,6	0,636	0,861	0,675	0,908	0,696	0,933
15	38,1	0,608	0,834	0,641	0,874	0,658	0,895
16	40,6	0,583	0,809	0,611	0,844	0,625	0,862
17	43,2	0,560	0,787	0,584	0,817	0,596	0,832
18	45,7	0,539	0,766	0,559	0,792	0,570	0,806
19	48,3	0,519	0,746	0,537	0,769	0,546	0,781
20	50,8	0,501	0,728	0,517	0,748	0,525	0,758
21	53,3	0,485	0,710	0,499	0,729	0,505	0,737
22	55,9	0,469	0,694	0,482	0,710	0,487	0,718
23	58,4	0,455	0,678	0,466	0,693	0,471	0,700
24	61,0	0,441	0,663	0,451	0,676	0,455	0,682
25	63,5	0,428	0,649	0,437	0,661	0,441	0,666
26	66,0	0,416	0,635	0,424	0,646	0,428	0,651
27	68,6	0,405	0,622	0,412	0,632	0,415	0,636
28	71,1	0,394	0,609	0,401	0,619	0,403	0,622
29	73,7	0,384	0,597	0,390	0,606	0,392	0,609
30	76,2	0,374	0,586	0,380	0,594	0,382	0,597

Cheers,
Aziz

[Aziz]

The Novel Tophat IB AI Coil vs. Mono Loop Coil

This is the novel so-called "Tophat" IB AI coil compared against the mono coil. Notice, this is an induction balanced anti-interference coil. The distance is referring to the co-axial distance between RX+ and the RX- coil part. BX coil being 4 mm apart from the RX- coil. TX and RX+ coils are concentric co-planar arranged.

Coil Comparison (Calculated Response Ratio to Reference Coil)
© 2012 by Aziz Ögüt. All Rights Reserved. 20-Dec-2012
Reference Coil: 300 µH Round Mono Loop Coil
		10" Tophat 0.71 CC IB AI Coil (5 inch distance)	10" Tophat 0.71 CC IB AI Coil (10 inch distance)	10" Tophat 0.5 CC IB AI Coil (5 inch distance)	10" Tophat 0.5 CC IB AI Coil (10 inch distance)	10" Tophat 0.33 CC IB AI Coil (5 inch distance)	10" Tophat 0.33 CC IB AI Coil (10 inch distance)
Target Depth [inch]	Target Depth [cm]	Relation to Reference	Relation to Reference	Relation to Reference	Relation to Reference	Relation to Reference	Relation to Reference
1	2,5	2,316	2,476	6,412	6,636	17,376	17,663
2	5,1	2,006	2,147	4,374	4,581	8,267	8,537
3	7,6	1,681	1,818	2,978	3,176	4,468	4,714
4	10,2	1,423	1,563	2,169	2,364	2,849	3,081
5	12,7	1,235	1,380	1,696	1,891	2,057	2,281
6	15,2	1,097	1,249	1,401	1,598	1,616	1,838
7	17,8	0,993	1,153	1,205	1,406	1,343	1,566
8	20,3	0,913	1,080	1,066	1,271	1,161	1,385
9	22,9	0,849	1,023	0,962	1,172	1,030	1,256
10	25,4	0,797	0,976	0,882	1,095	0,932	1,160
11	27,9	0,752	0,937	0,818	1,034	0,855	1,085
12	30,5	0,714	0,904	0,765	0,984	0,793	1,025
13	33,0	0,680	0,875	0,720	0,942	0,742	0,974
14	35,6	0,650	0,848	0,681	0,905	0,698	0,932
15	38,1	0,623	0,825	0,647	0,872	0,660	0,894
16	40,6	0,599	0,803	0,617	0,843	0,627	0,862
17	43,2	0,577	0,783	0,591	0,817	0,598	0,832
18	45,7	0,557	0,764	0,567	0,793	0,572	0,805
19	48,3	0,538	0,747	0,545	0,771	0,549	0,781
20	50,8	0,520	0,730	0,525	0,751	0,527	0,759
21	53,3	0,504	0,714	0,506	0,731	0,508	0,738
22	55,9	0,489	0,700	0,489	0,714	0,490	0,719
23	58,4	0,475	0,685	0,473	0,697	0,473	0,701
24	61,0	0,461	0,672	0,458	0,681	0,458	0,684
25	63,5	0,449	0,659	0,445	0,666	0,443	0,667
26	66,0	0,437	0,647	0,432	0,651	0,430	0,652
27	68,6	0,425	0,635	0,420	0,638	0,417	0,638
28	71,1	0,415	0,623	0,408	0,625	0,406	0,624
29	73,7	0,405	0,612	0,397	0,612	0,395	0,611
30	76,2	0,395	0,602	0,387	0,600	0,384	0,599

Let's calculate the break-even gain point for a specific depth (30 inch) and coil:
10" Tophat 0.5 CC IB AI Coil (10 inch distance): 0.6
Break-even gain: 1/0.6 = 1.67 (4.5 dB)
We need 1.67 times more gain to be equally good as a mono coil with the high inductivity RX coils. If you can't make high inductivity RX coils, we would require more gain of course (take a low-noise amp!).
Let's assume, our reference mono coil would have 20 turns for 10" diameter. The equivalent 5" RX+/RX- would have 4 times turns count of 20, so 4*20 = 80. 80 turns count for RX+ and 80 turns count for RX- coil.

Let's assume, our EMI noise rejection ratio would be 20 dB (x10) for the 10 inch co-axial distance.
Beneficial gain margin: 10/1.67 = 5.99 (20 dB - 4.5 dB = 15.5 dB)
(That should give a few more inches or cm of detection depth - hopefully *LOL*)

We aren't taking amplifier noise into account of course. Just use ultra low-noise amplifiers and you can crank up the gain until the EMI noise or other noise sources limits us.

Cheers
Aziz

[Aziz]

Hi guys,

let me finish all the other interesting coil configurations first before I make other calculations. Offsetting a targets position or orientation is not a problem of course. The current calculations were made along the hot spot axis (most sensitive axis).

And you must see the AI configurations as well. It's good to categorize the coils.

Cheers,
Aziz,
preparing another coil for publishing...