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  #101  
Old 07-10-2009, 02:30 AM
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Originally Posted by Max
SNRdB= -387.33
What?
Only -387.33 dB?
Maybe it would go lower if an earthworm who was near the surface burrowed down and helped to add some thermal gradient.

Hmmm... but wouldn't that just be more noise?

Best wishes,
J_P
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  #102  
Old 07-10-2009, 11:37 AM
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or... to put it simple... 12.9 yoctoTesla!

Kind regards,

Max
Thanks, for mentioning Tesla, IT'S HIS BIRTHDAY!!

I agree, an operating voltage derived from the Seebeck coeff. is about 1 million times to small to produce a measurable signal.

So, I won't use it.
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  #103  
Old 07-10-2009, 02:13 PM
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So, I won't use it.
You won´t use it where ?
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  #104  
Old 07-10-2009, 06:18 PM
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Thanks, for mentioning Tesla, IT'S HIS BIRTHDAY
Have you seen today's Google image?
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  #105  
Old 07-10-2009, 10:21 PM
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... and, continuing the subject of Tesla, here's an interesting article ->

http://atlasobscura.com/places/electrum
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  #106  
Old 07-10-2009, 10:37 PM
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In Tesla's birthday: (He's 10th July , I'm 6th July, as G. Bush )
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  #107  
Old 07-11-2009, 12:09 AM
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Default Temperature is NOT my best friend today!!!

If my proposed signal effect is "powered" by diurnal solar radiation then detectable depth is likely to max out at around 0.3 metres. .

Great illustration, Wish I'd found it earlier!!
The amount of "lag" is clearly shown too.

Not completely BUSTED, But definitely, Bruised & Battered.
Cheers, Aurificus
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  #108  
Old 07-11-2009, 01:40 AM
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... and, continuing the subject of Tesla, here's an interesting article ->
http://atlasobscura.com/places/electrum
Hi Qiaozhi,
And happy birthday Nicola Tesla..!!!

Remember this Telsa coil locator that Seden posted the Lockheed patent 5,982,180 for?
It is not a pistol type detector, but a full Tesla coil that produces sparks to locate buried objects.
When you see sparks, then you know you found something.
It was originally intended for land mine detection, but could be modified to find treasures as a hand-held portable model:
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  #109  
Old 07-11-2009, 02:10 PM
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Hi Qiaozhi,
And happy birthday Nicola Tesla..!!!

Remember this Telsa coil locator that Seden posted the Lockheed patent 5,982,180 for?
It is not a pistol type detector, but a full Tesla coil that produces sparks to locate buried objects.
When you see sparks, then you know you found something.
It was originally intended for land mine detection, but could be modified to find treasures as a hand-held portable model:
Hi,
I think who made this patent... was a joker... cause who really is so stupid to swing over a landmine an electrode with say 100000V potential ???

But sure... these "companies" are well known and trusted by government (sure they have brilliant scientists and technicians) and so patent anything that come in mind... for future (potential) use.

That's what I think of this patent... they found a potential application (though not so safe , indeed) and patented the "principle".

What's wrong with these devices is that if one have to use outdoor there's a serious risk to be struck by a lighting...

But maybe this is unimportant for the average LRL-user...beliver...

Kind regards,
Max
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  #110  
Old 07-11-2009, 02:12 PM
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Originally Posted by Esteban View Post
In Tesla's birthday: (He's 10th July , I'm 6th July, as G. Bush )
As said... before....

you're a natural born killer !

Anybody here MUST know that this "plan" is seriously dangerous... and make a mistake with that stuff could be THE LAST mistake you made!

Don't tell me... you realized many and all them work as LRL locating stuff at tens meters away ?

Kind regards,
Max
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  #111  
Old 07-11-2009, 03:16 PM
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As said... before....

you're a natural born killer !

Anybody here MUST know that this "plan" is seriously dangerous... and make a mistake with that stuff could be THE LAST mistake you made!

Don't tell me... you realized many and all them work as LRL locating stuff at tens meters away ?

Kind regards,
Max
Don't worry for me! At low current think is not letal, except for pacemaker user.

Regards
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  #112  
Old 07-11-2009, 04:56 PM
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Don't worry for me! At low current think is not letal, except for pacemaker user.

Regards
Hmmmm... you don't noticed the real danger.

If it creates a ionized area around a a sharp tip...

can actract lightnings ... in which case the current can rise also to some 200,000 amperes.... frying the pacemaker and everything around it!

Be careful... in your country there are big lightning storms...

Kind regards,
Max
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  #113  
Old 07-12-2009, 02:55 AM
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I think I may have over-reacted to the thermal change illustration.
It's a mathematical Model only and applies to a generic media (soil) and not the "target".

Max's elegant calculations apply to conventional circuits, but this is not what we have here.

I have struggled to to develop a schematic equivalent, mostly because they require the inclusion of "one-dimensional thin wires". (ODTW's are generally used by Scientists & EE to keep things "simple", so that the observed phenomena matches the formula.). This is a 3D open system

We have an excellent electrical & heat conductor "encased" (long-buried) in a semi conductor (significantly reduced electrical & heat conductivity by factors of hundreds)

A Schottky type barrier exists which provides capacitance for free electrons to collect & a "high speed switch" to allow them to flow when sufficient potential has developed.

We have have a thermal energy differential between the top of the of the target and the bottom. It might be "negligible" to some, but it is NOT zero. Electrons notice these things.

The Seebeck effect will operate "on top" of the potential maintained by the capacitance and "pump up the charge". Sort of more like an "electrotatic" build up than a conventional flowing current.

When sufficient forward voltage potential has been developed all of the charge will cross the barrier in "a Very Short Time". A pulse of EMR will be emitted.

The frequency, magnitude and periodicy of any such emissions are yet to be determined.

Discussion Invited
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Aurificus
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  #114  
Old 07-12-2009, 04:38 AM
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Originally Posted by Aurificus
I think I may have over-reacted to the thermal change illustration.
It's a mathematical Model only and applies to a generic media (soil) and not the "target". Max's elegant calculations apply to conventional circuits, but this is not what we have here.

I have struggled to to develop a schematic equivalent, mostly because they require the inclusion of "one-dimensional thin wires". (ODTW's are generally used by Scientists & EE to keep things "simple", so that the observed phenomena matches the formula.). This is a 3D open system

We have an excellent electrical & heat conductor "encased" (long-buried) in a semi conductor (significantly reduced electrical & heat conductivity by factors of hundreds)
Schottky type barrier exists
A Schottky type barrier exists which provides capacitance for free electrons to collect & a "high speed switch" to allow them to flow when sufficient potential has developed.

We have have a thermal energy differential between the top of the of the target and the bottom. It might be "negligible" to some, but it is NOT zero. Electrons notice these things.

The Seebeck effect will operate "on top" of the potential maintained by the capacitance and "pump up the charge". Sort of more like an "electrotatic" build up than a conventional flowing current.

When sufficient forward voltage potential has been developed all of the charge will cross the barrier in "a Very Short Time". A pulse of EMR will be emitted.

The frequency, magnitude and periodicy of any such emissions are yet to be determined.

Discussion Invited
Cheers,
Aurificus
Hi Aurificus,
It appears you changed your mind, and are again looking for ways to show that a thermal gradient will result in an electrical signal from a buried object.
Discussion invited? Ok.

First, let's start with the reason why you decided to re-examine the concept. According to your post, you concluded that Max's calculations don't apply to the actual phenomenon, and are only suitable for a simplified model. Thus new theories and calculations are justified to explain why your favourite concept of thermal gradient could be what's responsible for a IR LED receiving a signal.
So your basis to re-examine thermal gradient is that the logic used to show it can't work does not match the conditions at a buried metal object site.

Next we see your explanations of what is different at the buried metal object location. It is proposed in four stages:
1. "A Schottky type barrier exists which provides capacitance for free electrons to collect & a "high speed switch" to allow them to flow when sufficient potential has developed".
2. There is a thermal gradient from the top of the buried metal to the bottom. Maybe negligible, but not zero.
3. Because of this non-zero difference in temperature between the top of the buried metal and the bottom, we will find there is a voltage caused by the Seebeck effect, which will charge the expected capacitance due to the supposed Schottky diode effect which exists where metals are buried in the soil.
4. When the voltage becomes too great to be confined within the capacitance of the Schottky diode effect, the buried metal object is suddenly discharged into the soil, resulting the emanation of "a Very Short Time" pulse of EMR to be emitted into the soil.

Therefore, an IR LED will respond by variations in the pulse train that is sent to power it when pointed in the direction where the metal is buried.

If I understand your theories correctly, then here are the things that come to mind immediately that make me wonder why anyone would propose that theory:
1. The idea that Max's calculations are only a model and do not represent actual conditions may be true within an order of magnitude. But the idea that there is a thermal gradient from a real condition buried metal (coin for example) that has enough temperature difference to generate a voltage due to Seebeck effect seems many orders of magnitude unfeasible to me. It is also necessary to have a second metal present in the junction in order to produce a voltage. Somehow, I don't see the second metal, or the terminals where the voltage would be collected, or sent to the metal as a charge. Also, real soil has a lot of non-homogeneous temperature gradients in it caused by things like water tables and underground streams as well as moisture near the surface which is further complicated by plant roots and burrows made by small animals. I don't see your concept of the actual conditions at a buried metal site to be accurate for the purposes of proving the gradient will be adequate, or that there will be a voltage generated capable to build a measurable charge in a buried object due to Seebeck effect.
2. I will believe that a charge builds up in a buried metal object and exhibits a measurable Schottky diode effect to inject fast pulses into the soil when I see a test that demonstrates it is so. Do you have any experimental evidence to suggest this has occurred in the past for buried metals such as coins?
3. I will not believe there is any Seebeck effect charging the buried metal object until I see some experimental evidence to suggest that this actually happens in real conditions found for a buried coin. ie: Measure the voltage and current flow from this charge from a buried coin using a calibrated measuring instrument.
4. This collection of theories appears to be an attempt to prove that a particular favourite idea is correct, rather than to find out what works and what does not. But I could be wrong about that, I will be waiting to see some interesting experimental data to show that these theoretical thermal and semiconductor principles of buried metal are feasible.

Best wishes,
J_P
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  #115  
Old 07-12-2009, 02:53 PM
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If I understand your theories correctly, then here are the things that come to mind immediately that make me wonder why anyone would propose that theory:
1. The idea that Max's calculations are only a model and do not represent actual conditions may be true within an order of magnitude. But the idea that there is a thermal gradient from a real condition buried metal (coin for example) that has enough temperature difference to generate a voltage due to Seebeck effect seems many orders of magnitude unfeasible to me. It is also necessary to have a second metal present in the junction in order to produce a voltage. Somehow, I don't see the second metal, or the terminals where the voltage would be collected, or sent to the metal as a charge.............................. I don't see your concept of the actual conditions at a buried metal site to be accurate for the purposes of proving the gradient will be adequate, or that there will be a voltage generated capable to build a measurable charge in a buried object due to Seebeck effect.

J_P
No, I believe I said ...The moving thermal gradient gif is just a model.

Re; The Unfeasibility of Seebeck effects ..or otherwise.......

In 1821, the GermanEstonian physicist Thomas Johann Seebeck discovered that when any conductor is subjected to a thermal gradient, it will generate a voltage. This is now known as the thermoelectric effect or Seebeck effect.

Any attempt to measure this voltage necessarily involves connecting another conductor to the "hot" end. This additional conductor will then also experience the temperature gradient, and develop a voltage of its own which will oppose the original.

Fortunately, the magnitude of the effect depends on the metal in use. Using a dissimilar metal to complete the circuit creates a circuit in which the two legs generate different voltages, leaving a small difference in voltage available for measurement. That difference increases with temperature, and can typically be between 1 and 70 microvolts per degree Celsius (µV/°C) for the modern range of available metal combinations.


Introducing a Negative voltage when creating a circuit for measurement is what reduces the potential to muV.

My proposal doesn't have a real "circuit" until the potential is sufficient to break the metal to semi-conductor(soil) barrier.

cheers,
Aurificus
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  #116  
Old 07-12-2009, 04:34 PM
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Fortunately, the magnitude of the effect depends on the metal in use. Using a dissimilar metal to complete the circuit creates a circuit in which the two legs generate different voltages, leaving a small difference in voltage available for measurement. That difference increases with temperature, and can typically be between 1 and 70 microvolts per degree Celsius (µV/°C) for the modern range of available metal combinations.
cheers,
Aurificus
You've just described how a basic thermocouple works. These devices, when connected (by wires) to a suitable transmitter, have been in use for a very long tiime for measuring process temperatures. The other thing you are "sort of" talking about is a cold junction.

In any event these things only work when connected by wires to the measuring unit. They don't transmit anything through the air..... if that's what you were thinking.
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  #117  
Old 07-12-2009, 04:39 PM
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No, I believe I said ...

That difference increases with temperature, and can typically be between 1 and 70 microvolts per degree Celsius (µV/°C) for the modern range of available metal combinations.
It can be as you say.

Unfortunately (to aurificius method) soil act as everywhere on target connected constantly unlimited dumping resistor so nothing of microvolts even of nanovolts nor picovolts exist around metal target as thermovoltaic effect.

However, if we considers that the termovoltaic efect appear due to temperature changes in a fraction of the time, all this equally less smart, as changes in temperature drawn in the days and months, to offset mentioned effect to non existend.

Blinkig IR leds are nonsens cause due to lack of energy needed for thermovoltaic effect even when target is close and direct illuminated. In the ground, however, your weak infrared rays do not penetrate deeper than 0.5 cm in the best conditions and invalidate tehemselves due soil temperature hysteresis (second blinkig nonsens).

Suggestions: forget blinking IR rays and try with nonblinking gama rays, these penetrate deeper..

But as you say, you belive, so this is religious and not scientific question.
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  #118  
Old 07-12-2009, 10:08 PM
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Originally Posted by Aurificus
...Re; The Unfeasibility of Seebeck effects ..or otherwise.......

In 1821, the GermanEstonian physicist Thomas Johann Seebeck discovered that when any conductor is subjected to a thermal gradient, it will generate a voltage. This is now known as the thermoelectric effect or Seebeck effect.

Any attempt to measure this voltage necessarily involves connecting another conductor to the "hot" end. This additional conductor will then also experience the temperature gradient, and develop a voltage of its own which will oppose the original.

Fortunately, the magnitude of the effect depends on the metal in use. Using a dissimilar metal to complete the circuit creates a circuit in which the two legs generate different voltages, leaving a small difference in voltage available for measurement. That difference increases with temperature, and can typically be between 1 and 70 microvolts per degree Celsius (µV/°C) for the modern range of available metal combinations.


Introducing a Negative voltage when creating a circuit for measurement is what reduces the potential to muV.

My proposal doesn't have a real "circuit" until the potential is sufficient to break the metal to semi-conductor(soil) barrier.
Hi Aurificus,
Your proposal described a buried metal acting as a charged capacitor. A charged capacitor does not have a real "circuit" either until it is connected to something that will conduct the charge. This is also true of a battery, or any other device that can store a charge. Yet we can connect instruments that will measure the voltage these charged capacitors and batteries, and we can place an appropriate load to measure the current that will flow. There is no reason why the same cannot be done for a coin in the soil.

The Seebeck effect involves production of electrical power as a result of heat at the junction of two dissimilar metals. A buried coin does not have a junction with another dissimilar metal to generate electricity from a thermal gradient. Thus it is impossible to form a Seebeck junction unless there is a second metal for this junction.

But suppose we switch over to the Thompson effect, that better describes a single conductor charge in a thermal gradient. Would the charge be able to send out Schottky pulses of power? Lets start with the example of a capacitor, which has been suggested to represent the mechanism that allows charge to build up in a buried coin:

In the case of a capacitor at a workbench, there are also thermal gradients which are expected to be many orders of magnitude greater than the thermal gradient found at a buried coin. Even if the potential difference due to the thermal gradient found on a capacitor lead does not follow a complete circuit across the dielectric, the microvolt difference will be seen at the opposite polarity terminal where the conductive foil is found. this difference in microvolts will transfer through to the other terminal via capacitive coupling, as a voltage, although no substantial current will pass the dielectric.

If the end of the capacitor lead was found to be 1/10°C cooler than the foil end, then we might find there is 1uV difference between the foil end and the free end. This 1uV becomes part of the voltage that charges the capacitor, and is added to any voltage seen across the capacitor which arrived by other means. Thus the 1uV will be measured as part of the voltage reading when a voltmeter is connected to the two leads of the capacitor.

Suppose we charged a capacitor to exactly 10.000000 V, when the themperature was exactly uniform throughout the capacitor. Then if the lead of the capacitor closer to the table lamp by became 1/10°C warmer than the lead farther away, we would see the voltmeter change it's reading to 10.000010 V, due to the temperature difference between the leads. any thermocouple effects from the meter probes are canceled in the same manner as you already described.

However, we are talking about 1uV for a capacitor terminal in the air, which is expected to be exposed to much larger temperature variations than a buried coin. Suppose a coin is buried horizontally in a place where the thermal gradient does not go over 0.1°C/cm. and the thickness of the coin is 1mm. The most temperature gradient in the soil from the top of the coin to the bottom would be 1/100°C. But the thermal conductivity of a coin is much more than the soil around it. If it is a copper coin, the thermal conductivity of the coin will insure that it maintains a relatively constant temperature from top to bottom in spite of the 1/100°C gradient in the soil around it.
This is because the thermal conductivity of copper is over 100 times greater than any typical soil. Thus I would expect to see maybe 1/10,000°C variation within the coin when the soil reached its peak gradient. This results in less than 1/100 of the charge that we were previously counting on without considering the thermal conductivity of buried metal.
Thermal conductivity of things buried:
1 to 3 W/(m-K) soil, depending on composition
12-45 W/(m-K) stainless steel
35.3 W/(m-K) lead
120-220 W/(m-K) aluminum
318 W/(m-K) gold
380 W/(m-K) copper
429 W/(m-K) silver

Looking at the conductivity values, I would expect the thermal gradient concept would favour finding stainless steel and lead items with a much stronger gradient than copper, gold and silver. This makes me wounder why Esteban hasn't been talking about all the bullets and stainless steel stuff he found with his IR LED detector. Maybe because there is no where near enough heat or gradient to produce a charge in a buried coin, much less send out Schottky pulses that will signal a detector at distance.

I suppose that even if the metal had the same conductivity as the soil, I still can't imagine a way it could send a pulse of power through a "Schottky diode" effect forming around it. I can't even imagine how it could develop a charge that reaches over a microvolt strength.

Best wishes,
J_P
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  #119  
Old 07-13-2009, 01:41 PM
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You've just described how a basic thermocouple works. These devices, when connected (by wires) to a suitable transmitter, have been in use for a very long tiime for measuring process temperatures. The other thing you are "sort of" talking about is a cold junction.

In any event these things only work when connected by wires to the measuring unit. They don't transmit anything through the air..... if that's what you were thinking.
Hi,
yes , exactly... thermocouples give just weak signals... require preamplification, impedance matching etc... be connected with wires etc...

all right.

The idea of above I think it was about some kind of short turn in which the metal alone experiencing a suitable thermal gradient would expose a small voltage and current in the path to flow, very weak.
Or, in another post he wrote, about metal/soil interaction so one may expect (depending on soil composition) that a small voltage (order of 1uV/K) can develop at interface between the metal and the soil.
Some earth batteries work closing the "circuit" similar way... around an electric electrode of battery there's soil and ionic movement due to moisture/water-trapped (even root of plants!) make current flow... that's like telluric currents move in that surface layers...

The idea, as explained, is not completely non-sense to me... the problem is , also supposing that weak current flow around target possibly exist, that the current flow will create just a too weak magnetic field to be detected in any way... cause of the power of 3 attenuation of field strenght with distance.

The order of magnitude I see this stuff is the like you can have making e.g. a simple bimetallic turn and expose to sun... say copper/zinc stuff 30cm diameter... now... if you'll place a good compass in the middle you can (maybe) get a small deviation of needle if enough magnetic force is generated.

But , then, even if this experiment work... it's very different than e.g. thinking at a visible/measurable deviation of compass needle from 10 meters away... also the copper/zinc is an ideal case... and e.g. a gold target in soil matrix is quite different stuff.

Indeed, I think, this phenomenon are not suitable for long range detection cause no detector can be realized with required sensitivity and SNR to win the overwhelming effect of e.g. Earth magnetic field.

An interesting aspect of this stuff could be that a good/interesting test could be made with a very sensitive magnetometer... if the current really develops as described the magnetometer held just over the buried target could maybe locate the target even if out of range of common MDs.
Would be impressive e.g. detecting a coin at 1meter deep!
But, of course, just theory... I didn't made any experiement to confirm that... nor I'm not sure the things are like exposed... and the current really exist. Just ideas. (btw I haven't handy any mag at now to test)

Kind regards,
Max
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Old 07-13-2009, 02:34 PM
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From what i understood,,Esteban said that the IR leds are just a way to improve the radio detection, not a detection system by itself.

I wonder what is the local effect of a IR beam in a voltage gradient...
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Old 07-13-2009, 04:41 PM
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From what i understood,,Esteban said that the IR leds are just a way to improve the radio detection, not a detection system by itself.

I wonder what is the local effect of a IR beam in a voltage gradient...
Hi Fred,
The average voltage gradient in open air where Esteban uses the IR LED is 100v/m, but can be up to 300v/m, or less than zero. But on normal fair weather days will average 100v/m. According to LRL theory this gradient is much reduced locally above a long-time buried metal object, which could be the basis for the variations in the power pulses of an IR LED if it's power use is influenced by the voltage gradient where it is illuminating.

If you want to experiment with this, you could create an artificial local gradient using a high voltage source such as a neon sign transformer with rectifier and some metal plates and shielding. ie: build a semi-closed Faraday cage that has a controlled voltage gradient inside which can be adjusted to different amounts than the surrounding atmospheric gardient.

It is possible the IR LED is not responding to the local voltage gradient anomaly, and the fluctuations in the power pulses are caused by something else. Some voltage gradient experiments could help determine if this is the case.

Best wishes,
J_P
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Old 07-13-2009, 04:58 PM
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Originally Posted by Max
...The idea, as explained, is not completely non-sense to me... the problem is , also supposing that weak current flow around target possibly exist, that the current flow will create just a too weak magnetic field to be detected in any way... cause of the power of 3 attenuation of field strenght with distance.

The order of magnitude I see this stuff is the like you can have making e.g. a simple bimetallic turn and expose to sun... say copper/zinc stuff 30cm diameter... now... if you'll place a good compass in the middle you can (maybe) get a small deviation of needle if enough magnetic force is generated.

But , then, even if this experiment work... it's very different than e.g. thinking at a visible/measurable deviation of compass needle from 10 meters away... also the copper/zinc is an ideal case... and e.g. a gold target in soil matrix is quite different stuff.

...An interesting aspect of this stuff could be that a good/interesting test could be made with a very sensitive magnetometer... if the current really develops as described the magnetometer held just over the buried target could maybe locate the target even if out of range of common MDs.
Would be impressive e.g. detecting a coin at 1meter deep!
But, of course, just theory... I didn't made any experiement to confirm that... nor I'm not sure the things are like exposed... and the current really exist. Just ideas. (btw I haven't handy any mag at now to test)
This is easy to test with a US penny. US pennies are made of zinc with a copper outer layer. If you cut one in half, you can see the zinc core layer inside the copper shell. You could put a US penny in the sun and hols your magnetometer above it to see what effect you detect in ideal conditions. You could also arrange the penny so half of it is shaded, while the other half is in the sun from different angles to see if this makes any difference. Also try cutting the penny into different shapes to see if this makes any difference. My guess is you will detect no magnetic change that does not exist with the penny at a stabilized temperature throughout.

This will only serve to demonstrate that there is or is not a flow of current in the penny in the test condition. Of course, we do not expect a flow of current when no load is connected. So we can connect a sensitive voltmeter to see how much voltage the penny has aquired in it's thermal gradient.

If this test thermal gradient voltage test shows nothing conclusive, then we could try a third test by cutting the penny in half and carefully connecting a Schottky diode to the zinc core, and the other lead to the copper shell. When repeating the same experiments in different lighting conditions, you can see if you can detect any pulses of power moving through the diode. Any pulses are sure to be sensed on a magnetometer, or even a small coil nearby connected to an oscilloscope.

Best wishes,
J_P
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Old 07-13-2009, 07:09 PM
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This is easy to test with a US penny. US pennies are made of zinc with a copper outer layer. If you cut one in half, you can see the zinc core layer inside the copper shell. You could put a US penny in the sun and hols your magnetometer above it to see what effect you detect in ideal conditions. You could also arrange the penny so half of it is shaded, while the other half is in the sun from different angles to see if this makes any difference. Also try cutting the penny into different shapes to see if this makes any difference. My guess is you will detect no magnetic change that does not exist with the penny at a stabilized temperature throughout.

This will only serve to demonstrate that there is or is not a flow of current in the penny in the test condition. Of course, we do not expect a flow of current when no load is connected. So we can connect a sensitive voltmeter to see how much voltage the penny has aquired in it's thermal gradient.

If this test thermal gradient voltage test shows nothing conclusive, then we could try a third test by cutting the penny in half and carefully connecting a Schottky diode to the zinc core, and the other lead to the copper shell. When repeating the same experiments in different lighting conditions, you can see if you can detect any pulses of power moving through the diode. Any pulses are sure to be sensed on a magnetometer, or even a small coil nearby connected to an oscilloscope.

Best wishes,
J_P
Hi,
I don't belive in the EM pulse generation described by Aurificus but the experiment with two conductors, not only the penny stuff, but e.g. two wires of different metal like copper and zinc (or also some iron) could give some result if there will be some thermal gradient in the shorted turn.

If so... a simple sensitive galvanometer for that stuff... (I still have it in garage,hopefully) will read current even really small, if there is. No need of amplifiers etc... will just add noise in this case.

My instrument is old style... wood and glass made and can read maybe 10nA at end of scale!

Thompson like! Thompson era ? Thompson owned that ???

Maybe is from 1910... museum grade

Maybe I can read the dang current... if there is...

Kind regards,
Max
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Old 07-14-2009, 05:59 AM
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Default Experimental devices

Still all this talk of thermistors, bi-metal contacts, closed loops etc. etc.
all very standard, conventional stuff and well known (c1750-1915) to produce very small phenomena.


The 'Experiment' will require a metal conductor 'encased' in a large semi-conductor to create a fully enclosed Schottky type barrier.
The contact between conductor and external media will need to be "very" close, ie. with some electron sharing (like..say.. long time "buried")

Energy source will be a thermal gradient between top of media and bottom.
Energy transfer into the metal will be greater than transfer out, leading to an increase of the internal energy.
This will excite electrons in the metal and cause them to seek the lower energy areas at the lower boundary surfaces.(charge carrier diffusion)

They will be held at this surface by the increasing energy level behind them. They cannot transfer their energy out quickly due to the lower temp gradient at the bottom compared to the top and they are trying to transfer energy to a low thermal conductive material by phononic atomic vibration (slower).

They will also create a voltage potential across the barrier by displacing electrons in the semiconductor medium. When the potential has reached the forward voltage requirement (say, .2 -.5V for commercial Schottkys, who knows for this?) a current will flow across the barrier. It is a function of the Schottky barrier that the switching takes micro seconds.

The current might be small but is extremely quick resulting in a brief but intense pulse of EMR maybe several mW. or even more, possibly quite detectable from a distance.

Question is... how to build such an experimental device?

They appear to be rather rare and hard to find in nature!!
And the exposing of a potential find destroys the "structure".

Remember also that, the introduction of wires between separate elements
with different temperatures and crating a circuit will produce their own voltage potentials by Seebeck/Thompson/Lord Kelvin .... Thermoelectric effects.... which may negate the potential required for the device to function.

Phew,
Aurificus

PS. This is just a theory to explain a reported phenomena no need to "git all het up"
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Old 07-14-2009, 01:34 PM
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It is a function of the Schottky barrier that the switching takes micro seconds.
Reverse recovery time

The most important difference between p-n and Schottky diode is reverse recovery time, when the diode switches from non-conducting to conducting state and vice versa. Where in a p-n diode the reverse recovery time can be in the order of hundreds of nanoseconds and less than 100 ns for fast diodes, Schottky diodes do not have a recovery time, as there is nothing to recover from. The switching time is ~100 ps for the small signal diodes, and up to tens of nanoseconds for special high-capacity power diodes. With p-n junction switching, there is also a reverse recovery current, which in high-power semiconductors brings increased EMI noise. With Schottky diodes switching instantly with only slight capacitive loading, this is much less of a concern.

OOPS! Sorry, Switch time down by X10,000. Output power up by....X10,000
or current required, reduced....x10,000

cheers,
Aurificus
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