I'm looking to build a simple feedback type oscillator circuit where the 'XTAL' is a sample of a substance to be located. The idea is to "spike" a vibratory mode to induce a resonance coupling between the sample in the device and samples to be located via electromagnetic coil. This coupling can easily pin-point where the object is trough the signal amplitude intensity. Any Schematics?

 

Sounds similar to a Syncrometer.

What do you mean by "located"? If you have a sample of a substance don't you already know its location?

ak

 

To "Comb" a unique harmonic signature in comparison to a known sample. To find more of it! What is a Syncrometer? The Google definition seems ambiguous and shrouded in mystery...

 

To "Comb" a unique harmonic signature in comparison to a known sample.

What does that mean? Note that you are on an electronic circuits forum. In our little world, "comb" has specific meanings, such as a "comb filter", an architecture that has multiple, harmonically-related passband notches.

ak

 

Google: A comb circuit (most commonly known as a comb generator) is an electronic circuit that takes an input frequency and distorts or modulates it to produce a wide spectrum of evenly spaced harmonic frequencies, resembling the teeth of a comb.

 

I'm looking to build a simple feedback type oscillator circuit where the 'XTAL' is a sample of a substance to be located. The idea is to "spike" a vibratory mode to induce a resonance coupling between the sample in the device and samples to be located via electromagnetic coil. This coupling can easily pin-point where the object is trough the signal amplitude intensity. Any Schematics?

The presumption that materials posess a "resonant vibratory mode" that can somehow be excited by an external field is an interesting concept that has generally been found to not be valid in the real world. The one application has been in a "magnetic nuclear resonance "mass spectrometer, which is a rather large and expensive research system. Those machines have been used in some research laboratories. They are far from simple, and quite expensive. They are able to analyze small samples of materials.

 

The presumption that materials posess a "resonant vibratory mode" that can somehow be excited by an external field is an interesting concept that has generally been found to not be valid in the real world. The one application has been in a "magnetic resonance mass spectrometer", which is a rather large and expensive research system. Those machines have been used in some research laboratories. They are far from simple, and quite expensive.

Not to be "valid" in the real world then you go on to say that they are expensive... If you don't have anything constructive to say then just move along!

 

Any Suggestions?

 

The circuits shown in post #8 would certainly be able to sense any resonant system within some range. That response would not depend on what the resonant circuit was, except for the magnitude of the resonse to the signal, and the separation between that circuit and the detection system. So there are at least two unknown quantities involved. Certainly the serch and research will be quite revealing.
My comment about the high cost is based on what a technically skiled friend of mine paid for a similar, but not identical, sensing system. Given what I saw demonstrated apperaing to be a lack of the anticipated response I am a bit skeptical.
BUT one lack of anticipated response of a system that I do notfully understand does not constitute a failure.

 

The circuits shown in post #8 would certainly be able to sense any resonant system within some range. That response would not depend on what the resonant circuit was, except for the magnitude of the resonse to the signal, and the separation between that circuit and the detection system. So there are at least two unknown quantities involved. Certainly the serch and research will be quite revealing.
My comment about the high cost is based on what a technically skiled friend of mine paid for a similar, but not identical, sensing system. Given what I saw demonstrated apperaing to be a lack of the anticipated response I am a bit skeptical.
BUT one lack of anticipated response of a system that I do notfully understand does not constitute a failure.

Feel free to ask around for agreement on a standard solution!

 

For any measurement or detection system the big question is always what physical signal is to be sensed and detected. The limitation of many electrical detection systems is sensitivity to the property they are to sense. Detection of a voltage field of some polarity and magnitude is fairly well developed. Detection of rediated alternating electrostatic fields, such as RF, is very well developed.

 

For any measurement or detection system the big question is always what physical signal is to be sensed and detected. The limitation of many electrical detection systems is sensitivity to the property they are to sense. Detection of a voltage field of some polarity and magnitude is fairly well developed. Detection of rediated alternating electrostatic fields, such as RF, is very well developed.

So what do you propose?

 

The system in post #8 is certainly an example of what I was describing. The missing information is about the resonant frequency of whatever the search is for. So the BIG QUESTION FOR THE TS is obviously "What is the resonant frequency of whatever they are seeking??" THAT is the one bit of iformation that we do not have. Of Course, it is certainly possible that whatever is being searched for DOES NOT HAVE A RESONANT FREQUENCY. Gold, silver, and even copper, do not have any "Natural Resonant Frequency" at all, at least, not that I am aware of. "Natural Resonant Frequency" is certainly a a wonderful property for a mineral or a metal to have, but it simply does not happen. BUT it makes a very good fable story,

 

They do, are you familiar with 'Emission Lines'? (https://en.wikipedia.org/wiki/Emission_spectrum) And can be extrapolated through the electromagnetic spectrum!

 

It seems that there must be some enegy added somhow to power those emissions. That adding energy may be the challenge. I have heard a number of fables presented by folks who either never studied the "science of materials", or are seeking to commit theft by fraud.

The "natural vibrations of materials" does not seems to agree with what is known in the many fields of science. NOR have I come across it in any engineering documents of any kind during my career, so far.
Perhaps if any other folks who visit these forums are aware of such, and understand how those vibrations relate to what is presently known and understood about atomic structure, those individuals could comment. Perhaps our educations are lacking in some area?

 

I'm looking to build a simple feedback type oscillator circuit where the 'XTAL' is a sample of a substance to be located. The idea is to "spike" a vibratory mode to induce a resonance coupling between the sample in the device and samples to be located via electromagnetic coil. This coupling can easily pin-point where the object is trough the signal amplitude intensity. Any Schematics?

Piezoelectric oscillator circuits work only with materials that demonstrate the piezoelectric effect. You can't arbitrarily substitute a material where the schematic says XTAL.

MRS and the related NMR use liquid helium cooled superconducting magnets to orient the orbits of the electrons in molecules and sensitive radio receivers to detect the resulting signals which are signatures of different materials.

I can't see how your proposal—even if it was workable—has anything to do with MRS. Could you explain you application?

 

ManyTHANKS to "Y" for much more clearly stating the point that I made: The material being sought after would ALSO need to have piezoelectric properties to deliver any response to an external electrical field.
The concept of vibrations has been used by fraudsters for many decades.
It is an interesting concept not verified by ANY CREDIBLE RESEARCH.

 

Piezoelectric oscillator circuits work only with materials that demonstrate the piezoelectric effect. You can't arbitrarily substitute a material where the schematic says XTAL.

MRS and the related NMR use liquid helium cooled superconducting magnets to orient the orbits of the electrons in molecules and sensitive radio receivers to detect the resulting signals which are signatures of different materials.

I can't see how your proposal—even if it was workable—has anything to do with MRS. Could you explain you application?

Every material has electrons...

 

So now it is clear that the system described would be capable of detecting materials with resonant piezoelectric properties. The terribly bad news is that description and property does not apply to most valuable minerals, nor ANY valuable metals, nor even aluminum, copper, or silver. So the concept is quite interesting indeed, and useful for finding a specific class of materials. But not the precious ones.

 

So now it is clear that the system described would be capable of detecting materials with resonant piezoelectric properties. The terribly bad news is that description and property does not apply to most valuable minerals, nor ANY valuable metals, nor even aluminum, copper, or silver. So the concept is quite interesting indeed, and useful for finding a specific class of materials. But not the precious ones.

How would you handle the "precious ones"?