Skin Effect

[Qiaozhi]

I know zahori.ofcourse it is not metal detector.I wanted to mean effect of high voltage line.when voltage increases effect also increases.

I suppose the search head could conceivably be a sophisticated coil arrangement. Possibly even tuned to full resonance like the Nexus coils, but the detection range claimed is somewhat unbelieveable.
Can you confirm that you are claiming it could detect a gold coin at 4m?

[Unregistered]

It is my father's experience.
at that occasion ,they measured 4 mmeters dept for gold.
they digged when reached 3.5 diggers found a small cup made of mud.
then they went on digging.when they reached 4 meters thet said "please use detector again we digged too much."
they they measured again.there were no sound at machine.then the owner of machine wanted cup from my father.and break it with a rock.and it broke with flash and gave gas which burned his hand.it'S burned is still can be seen on his hand.and there was a thin (like stamp)gold coin inside
let's say not coin ,cup detected at that time.and there was a halo effect but still it is small target to detect from 4 meters and .this machine did that detection.
for me I can not believe as you .but my father says this.and I believe him
it is realy different.because todays detector need biggercoil to detect deep .
it was a copy of prototype.only produced 2 piece as I know.

[okantex]

hi
what is the aim of germanium diodes in parallel connection.
this could be connected to circuit to adjust something.
because (yellows are wires.)wire in transistor leg uses the same wire with resistor network which have values of (0,82k,two missing resistor,5.62k,7.89k,10.18k ,13.4k ,18.9k ,19.77k ,30.7k ,41.8k ,48k)

[Unregistered]

hi
T1 ,T2 of this circuit and it's connections with cappacitances looks like mines.
it has some similarities.
http://geotech.thunting.com/pages/me.../US3875498.pdf

[Qiaozhi]

It is my father's experience.
at that occasion ,they measured 4 mmeters dept for gold.
they digged when reached 3.5 diggers found a small cup made of mud.
then they went on digging.when they reached 4 meters thet said "please use detector again we digged too much."
they they measured again.there were no sound at machine.then the owner of machine wanted cup from my father.and break it with a rock.and it broke with flash and gave gas which burned his hand.it'S burned is still can be seen on his hand.and there was a thin (like stamp)gold coin inside
let's say not coin ,cup detected at that time.and there was a halo effect but still it is small target to detect from 4 meters and .this machine did that detection.
for me I can not believe as you .but my father says this.and I believe him
it is realy different.because todays detector need biggercoil to detect deep .
it was a copy of prototype.only produced 2 piece as I know.

If your father's recollection of the events is correct, then the secret is in the search head coil arrangement, not the electronics. This circuit is too simple to be anything special.

[Qiaozhi]

hi
what is the aim of germanium diodes in parallel connection.
this could be connected to circuit to adjust something.
because (yellows are wires.)wire in transistor leg uses the same wire with resistor network which have values of (0,82k,two missing resistor,5.62k,7.89k,10.18k ,13.4k ,18.9k ,19.77k ,30.7k ,41.8k ,48k)

It is quite common to see two parallel diodes in the feedback path of an opamp in order to produce clipping of the output waveform. Take a look at the Bandido II umax circuit diagram on this website as an example.
Presumably these diodes have a similiar purpose here.

[Qiaozhi]

hi
T1 ,T2 of this circuit and it's connections with cappacitances looks like mines.
it has some similarities.
http://geotech.thunting.com/pages/me.../US3875498.pdf

Interesting. This design does have some similiarities. It appears to be a variation on the BFO, but with much improved discrimination, with the oscillators operating at 54kHz.
Have you tried building it?

[Unregistered]

"It is quite common to see two parallel diodes in the feedback path of an opamp in order to produce clipping of the output waveform. Take a look at the Bandido II umax circuit diagram on this website as an example.
Presumably these diodes have a similiar purpose here.
"
but in bandido diodes are parallel to cap,resistor and op-amp
in mine there is no cap ,resisitor in series and how can transisitor be in paralel
you know I am not EE.
if there is wrong in my ideas about connections of circuit ,please redarw it on paint program and sent please

[okantex]

Hi ,
in most of the BFOs in this site,low amper transistors used like 2n2222 ,bc548 (0,1A or 0,2A)30V
but at the link I gave and in mine there are high amper transistors .
in mine mp16A which must be 0,5A (mpsa14 30V 0.5A , mpsa05 60V 0.5A)
in the link GE2n6008 and 2n6009 (35V 5A 4w
can this be solution of problem.
in mine there is only one transistor like this and it is( npn )in reciever part in my opinion designer useed transformer in transmitter .there current decrease and voltage increase and high voltage penetrare much.
I wonder something about transistors?
do the y just increase amper .or can they both amper and voltage at the same time?
I wonder what does my mp16?increase amper or voltage?

Does transformer has adventage over transistor ?
İf these high amper transistors used in circuit mens ,there iş high current in DRAINs .if so while reducing it to 0,1A ,we can increase vaotage four or five times more.
And form large fluxes.and by using iron core whose inerside isempty(hole),we will achive higher polarization and due to this more dept.
And while recieving reflected signal ,this iron wwill help us to collect more fluxes and increase amper.also means recieving weak signals.

[okantex]

sorry iron cannot be seen in previous pic because of fluxes.

[Esteban]

Does transformer has adventage over transistor ?

The old Magnetic Resonant Amplifier technique. You can see in these 2 files info about combination core + coil + piezo element.

Maybe this is the info you're looking:

[Qiaozhi]

Does transformer has adventage over transistor ?

In this application I would say "no". Magnetic amplifiers (to which I assume you're refering) only have advantages in some limited areas. They are mainly used as power amplifiers and have a frequency response of about 100Hz.

[Esteban]

They are mainly used as power amplifiers and have a frequency response of about 100Hz.

100 Hz? Any iron-alloy cores can work at various kHz. Ordinary cores can use in frequency range few hertz to 15 kHz and special ferrite-alloys core very high. Of what you're talking? Maybe typo error? Is this a joke?

Here a link. Also post a table.

http://www.fis.unb.br/Fis3Exp/fcim.csdc.com/fcimis/compid/ind/toroid.html

[Qiaozhi]

They are mainly used as power amplifiers and have a frequency response of about 100Hz.

100 Hz? Any iron-alloy cores can work at various kHz. Ordinary cores can use in frequency range few hertz to 15 kHz and special ferrite-alloys core very high. Of what you're talking? Maybe typo error? Is this a joke?

Here a link. Also post a table.

http://www.fis.unb.br/Fis3Exp/fcim.csdc.com/fcimis/compid/ind/toroid.html

I think we're talking about two different things. You mentioned magnetic resonance amplifiers, but I was refering to a magnetic amplifier. This contains a transductor (not to be confused with transducers). Amplification is achieved by making use of the nonlinear properties of ferromagnetic materials. A transductor is the basic amplifying element in a magnetic amplifier in which the input signal is a voltage applied to a coil linking an iron-cored system. A low impedance source of alternating emf (which carries the load current) is also applied to other coils linking the system. If the signal current is alternated, the flux levels in the core will be modified. Hence, the operating conditions in the load circuit are changed which, in turn, modulates the load current. By careful design, the power necessary to polarise the core material can be much smaller than the power being controlled in the load circuit. It may be possible with more modern materials to increase the operating frequency, but in general 100Hz is about right.
What's happening here is that electromagnetism is being used to provide amplification. It is not amplification of magnetism, as the name might suggest.
Anyway, I doubt that either an MRA or a magnetic amplifier have anything to do with this unusual detector.

[Esteban]

Okantex said:

I learned all from the owner.
he said in head ,there was crystal and really small four selenoid windins .
four of them were positioned like a circle and perpendecular to 1. and 2.

The Magnetic Resonance Amplifier is in concordance with the image he post: