TESORO GOLDEN SABRE

[wild_desert]

Hi,
it's like in digital VLFs: usually the phase of sampling gates is controlledby the MCU , often another MCU or the same do also the reading of values after adc stuff and make other computations, like for VID stuff, related to "phase" of targets.

If you try to generate the phase for sampling using the MCU you'll sure have easy work... just need to sync using an interrupt driven routine and use internal timer(s) to generate an opportune delay(s).

The adc reading, instead, seems much harder work if you'll use just simple sampling strategy... require hi-priced device to do so, the internal adc will fail on that if there aren't analog blocks before it, e.g. like just after sampling gates.

You could use another strategy: numerical integration.

Look for Robert Hoolko's project , it's a thread inside this forum: he made something similar and works, but then abandoned the project.

Kind regards,
Max

Hi Max
I don't want to do sampling on sine wave, although that is better but the ADC become expensive and busy the micro.

[ivconic]

Ivonic,

Looking also to experiment with center tapped coil. Here you say "Center tapped coil means only TX with center tap." I thought Rx was center tapped coil?
After looking at pcb connections this is only way make sense.

How is new scope working? Any new information on these coils?

Molzar

Did i wrote "TX"...???!?!?!? Yes i did!!!

Sorry, typing error! RX is center tapped NOT TX!!

Molzar thank you for observation and remark!
Best regards!

[Max]

Thanks to Max and Qiaozhi
Ex me for my delay(I have to make circuits for living and MD is my research).
You said: we must have 2 demodulator simultaneously. one for detecting phase change and other for amplitude change. And an or logic for detecting a target.
Is it true?
If true i say: micro can make precisely 2 squre wave needed for 2 demodulator and 2 low pass filter can make smooth dc voltage. next two 10bit ADC of AVR will sample dc voltages and micro can compare it with presaved numbers. any change in any channel means metal vicinity. Then micro can change phase clocks for discrimination purpose.
You see, we may have smaller circuit with more flexibility. Instead of potentiometers we have keyboard. Also auto GEB is a short procedure in our program. we can change many parameters by 4 keys + a basic LCD + menus.
I wait your answer
Kind regards

Hi,
it's like in digital VLFs: usually the phase of sampling gates is controlledby the MCU , often another MCU or the same do also the reading of values after adc stuff and make other computations, like for VID stuff, related to "phase" of targets.

If you try to generate the phase for sampling using the MCU you'll sure have easy work... just need to sync using an interrupt driven routine and use internal timer(s) to generate an opportune delay(s).

The adc reading, instead, seems much harder work if you'll use just simple sampling strategy... require hi-priced device to do so, the internal adc will fail on that if there aren't analog blocks before it, e.g. like just after sampling gates.

You could use another strategy: numerical integration.

Look for Robert Hoolko's project , it's a thread inside this forum: he made something similar and works, but then abandoned the project.

Kind regards,
Max

[wild_desert]

Thanks to Max and Qiaozhi
Ex me for my delay(I have to make circuits for living and MD is my research).
You said: we must have 2 demodulator simultaneously. one for detecting phase change and other for amplitude change. And an or logic for detecting a target.
Is it true?
If true i say: micro can make precisely 2 squre wave needed for 2 demodulator and 2 low pass filter can make smooth dc voltage. next two 10bit ADC of AVR will sample dc voltages and micro can compare it with presaved numbers. any change in any channel means metal vicinity. Then micro can change phase clocks for discrimination purpose.
You see, we may have smaller circuit with more flexibility. Instead of potentiometers we have keyboard. Also auto GEB is a short procedure in our program. we can change many parameters by 4 keys + a basic LCD + menus.
I wait your answer
Kind regards

[amtech2005]

TESORO GOLDEN SABRE

Hello , I found the answer from Ivconics earlier post , about the "TX" Center tap connection to ground........Thanks.................Eugene

[amtech2005]

TESORO GOLDEN SABRE

Hello All , If a Center tap on the Tx coil , or even the RX coil helps , than use it !! Does the center tap go to a Ground or a shield wire ?? Or are we suppose to read 2 separate resistance values on one winding , and is the center tap creating a phase cancellation ??? The Tesoro coil charts posted just have a TX and Rx resistance value . Must be to ground because there is only a 5 pin connector ??................Thanks..............Eugene

[Molzar]

PCB not ready yet. When ready i will post it for sure.
Center tapped coil means only TX with center tap. For example i used 0.25mm wire and 54+54 windings on already explained coil form/holder.
Wiring differs a bit. TX ends are connected with separate coated wires through cable. Center tap is connected to gnd at pcb. TX ends are connected at proper spots at pcb. Both faraday cages are also connected at gnd on cable (shield) and on pcb gnd.
Cheers!

Ivonic,

Looking also to experiment with center tapped coil. Here you say "Center tapped coil means only TX with center tap." I thought Rx was center tapped coil?
After looking at pcb connections this is only way make sense.

How is new scope working? Any new information on these coils?

Molzar

help

Zdravo,

Stevan mi je rekao da mi ti mozda mozes pomoci. Imam Atlantis imperator. kupio sam ga pre mesec dana. Medjutim, kada sam ga probao pistao je na sve, iako sam ukljucio diskriminaciju. Otvorio sam ga i video da je vec radjeno nesto. Verovatno su mu pomerali ona 4 trimera. 3 plava i 1 mali okrugli. Da li ti imas semu za njega, ili mi mozes nekako drugacije pomoci. Ako imas vec takav, da li bi mogao da izmeris vrednosti tj. otpor pa da mi posaljes? Unapred zahvalan. Goran.

[Max]

Can you explain in more detail what you are trying to achieve here?
Why do you only want to use one demodulator?


Your description is basically correct, but I'm not sure what wild_desert is trying to do. It doesn't make any sense at the moment. We need to wait for an answer.

Hi,
I think he wanna use one channel "demodulator" ... some sampling stuff connected to something atmel MCU.

But the problem is that usually there are two channels... one for geb and the other for disc path.

In case of amplitude stuff he'll use ADC; for phase issue instead he would use (probably) a comparator only.

But we know the problem is somehow a bit more complex...

Kind regards,
Max

[Qiaozhi]

I want to make it with only one demodulator that phase angle of square wave signal changes by a micro(phase scanner).
in my initial tests i saw some metals change only phase angel and others change amplitude!
i was confused. i'm searching what? phase shift or amplitude change?
why the resonat frequency of TX and RX must be different?
if i have Block Diagram, i can find answers.

Can you explain in more detail what you are trying to achieve here?
Why do you only want to use one demodulator?

Hi,
no... I haven't, sorry. But it's quite easy identify various parts... you have op amps used as phase shifters that control the gate of fets... fets are the sampling devices in TGS. That's about same stuff for disc and gnd parts... you have 2 phase shifter networks and 2 fets for that (TGSL).

After the fets there are the low pass filters... so are other blocks.

All tesoro coils for uMax shift to the left (I saw that on 9x8 and 8 round but think they are all the same about this) when a metal is near, no matter of kind of metal, are eddy currents that make it happens. The non-ferrous give rise in amplitude... and iron gives a fall in amplitude at rx, this is related to flux lines behaviour.

It's a bit complex issue: on geb channel you get amplitude variations that are driven actually by phase shift introduced by targets.
In the disc channel you get, instead, amplitude variations related to amplitude variations at rx coil.

It's so cause geb channel don't care about target composition but only that mineral response need to be ignored.

But you'll better ask Qiaozhi about subtle details, he knows about these designs strategies very, very good.

Kind regards,
Max

Your description is basically correct, but I'm not sure what wild_desert is trying to do. It doesn't make any sense at the moment. We need to wait for an answer.

[ivconic]

No,
as i stated many times - 1e coin!

[Noemio]

Question for IVCONIC

Hi Ivica,

Just a little question: is this the kind of coin you use to compare your MD’s performances?

Thank you

[Max]

Hi Max
Do you have Block diagram of TGSL?
I want to make it with only one demodulator that phase angle of square wave signal changes by a micro(phase scanner).
in my initial tests i saw some metals change only phase angel and others change amplitude!
i was confused. i'm searching what? phase shift or amplitude change?
why the resonat frequency of TX and RX must be different?
if i have Block Diagram, i can find answers.

Hi,
no... I haven't, sorry. But it's quite easy identify various parts... you have op amps used as phase shifters that control the gate of fets... fets are the sampling devices in TGS. That's about same stuff for disc and gnd parts... you have 2 phase shifter networks and 2 fets for that (TGSL).

After the fets there are the low pass filters... so are other blocks.

All tesoro coils for uMax shift to the left (I saw that on 9x8 and 8 round but think they are all the same about this) when a metal is near, no matter of kind of metal, are eddy currents that make it happens. The non-ferrous give rise in amplitude... and iron gives a fall in amplitude at rx, this is related to flux lines behaviour.

It's a bit complex issue: on geb channel you get amplitude variations that are driven actually by phase shift introduced by targets.
In the disc channel you get, instead, amplitude variations related to amplitude variations at rx coil.

It's so cause geb channel don't care about target composition but only that mineral response need to be ignored.

But you'll better ask Qiaozhi about subtle details, he knows about these designs strategies very, very good.

Kind regards,
Max

[wild_desert]

Hi Max
Do you have Block diagram of TGSL?
I want to make it with only one demodulator that phase angle of square wave signal changes by a micro(phase scanner).
in my initial tests i saw some metals change only phase angel and others change amplitude!
i was confused. i'm searching what? phase shift or amplitude change?
why the resonat frequency of TX and RX must be different?
if i have Block Diagram, i can find answers.

[Max]

Hi...
I want to TGSL 1265 so I've a problem.
What is the TGSL 1265 coil's measurements?
Regards.....

Hi,
I will not repeat that numbers again in the future... cause we already made several times... now cause the thread is so long and a correct search is about time wasting I do for you, once again.

You need 100 turns for TX, 105 for RX, wire 30AWG, you have to make DD coil about 11'' diameter... forget about inductance and resistance values: just try to match 14.6Khz at tx oscillator using 100turns (you could also try adding or removing few turns... but I tell you that 100turns is the right number if the wire is right and former too).
On RX you have to null for minimal residual voltage.

And you'll have a working coil. Could tweak reading all that posts, find it.

To have an idea of former and dimensions look at page 39, for signals look at page 57.

Kind regards,
Max