Detector #2

[Fred]

Great job.I like its simplicity.
Even if it doesn´t work, you may eventually find something with it.
An it may help to say that it could work better with a microcontroller, even if you don´t know why.
Please keep us informed with the results.

[Funfinder]

Quite cool.

The scotch tape is effective for concealing the wire connections to prevent reverse engineering.
Will the production model be built on a standard PCB or SMT?

Best wishes,
J_P

Thx J_P , it's a quite cool design - I'm always happy if in the end I created something I'm liking, too - because when I start often I have no idea how and with which parts I should begin...

The tape only is for isolation and stability and not to prevent reverse engineering.

And I have to hurry creating the final schematic out of my mind otherwise the tape will prevent me of this...

I guess standard pcb... smt could burn through...

[Funfinder]

Great job.I like its simplicity.
Even if it doesn´t work, you may eventually find something with it.
An it may help to say that it could work better with a microcontroller, even if you don´t know why.
Please keep us informed with the results.

It's really absolutly not that simple as it may look and:
it works already with microcontrollers!

[Funfinder]

So, do we get to see the schematic.

AND the test results ??

Goldfinder

PS - Great to see someone doing something besides critisizing, and condeming what some else's ideas. Real progress we all hope for!

Perhaps it depends on the "real" test results if I publish the schematic.

And maybe also if someone really knowledged is willing to analyze what the circuit does...
Because I'm not completly shure about this - seems it uses some kind of resonance circuit that only establishes under special circumstances - resulting in this very sensitive threshold noise. That shortcuted emitter-basis connection of T1 (see above) also is very important.

Goldfinder, you're right, crizisizing is funny and easy, building such stuff alot serious work and "headache" if there occure unexpected problems - and those will...

Now I understand much better why some metal detectors are a bit more expensive as flat screen LCDs etc. Developing such stuff devours a huge amount of time, work and nerves...

[J_Player]

Thx J_P , it's a quite cool design - I'm always happy if in the end I created something I'm liking, too - because when I start often I have no idea how and with which parts I should begin...

The tape only is for isolation and stability and not to prevent reverse engineering.

And I have to hurry creating the final schematic out of my mind otherwise the tape will prevent me of this...

I guess standard pcb... smt could burn through...

From reading your earlier posts, I figured you would take measures to keep some parts of the circuit low noise and free from interference. I can see you have two separate sections of circuitry which appear to be isolated in separate tape bundles, and there is no circuit board. The point-to-point direct soldering helps to keep the lead lengths short which may be necessary for certain components.

This made me think you used this kind of construction intentionally to minimize the conductor lengths, while saving time with circuit boards. I figured if you wanted to maintain the same short lead length on a production model, you would choose SMT. But these are harder to work with when hand-built, so a well-designed circuit board may work better.

Actually this prototype construction method is not a bad idea. The last LRL construction I was involved with was wired with the same method. Too bad the circuit designer was banned from the forum before I finished the LRL. It was said to be good for detecting TVs from the couch, and static fields from a large distance.

Best wishes,
J_P

[Funfinder]

> And I have to hurry creating the final schematic out of my mind otherwise the tape will prevent me of this...

Well, I was lucky! *knock on wood*

[Fred]

And maybe also if someone really knowledged is willing to analyze what the circuit does...

Choosing someone knowledged has never been a good idea for those kind of circuits.
People with no knowledge will give you more interesting answers about the principle, if you need names i may be of help.

[J_Player]

Choosing someone knowledged has never been a good idea for those kind of circuits.
People with no knowledge will give you more interesting answers about the principle, if you need names i may be of help.

I agree.
mikebg is probably among the best forum experimenters I can think of who is knowledgeable of how to design and optimize circuits for metal detecting.
But I doubt he would be able to analyze what this circuit does or is intended to do other than to amplify something between a large metal plate, a coil and a finger on an emitter lead.

Maybe a good starting point is to define exactly what kind of kind of field signal you want the circuit to detect or demodulate before enlisting help to analyze it.
Or if that can't be done, then I think Fred has a good solution.

Best wishes,
J_P

[detectoman]

funfinder, whit these strange project, stuff of extremely poor man in time of crisis, i remember the rudimentary laboratory of dr frankenstein
btw may brhy, the important is what these has function, you keep then far of evrentis-artemis ltd eyes, or soon you look you project in internet sales by pay pal
you keep then top secret how today
may congratulations, soon we seeing you tries videos?

[detectoman]

may be same built tegnologie how funfinder designs jaajii

http://www.youtube.com/watch?v=lIsNHMpEBYQ&feature=related

[Qiaozhi]

may be same built tegnologie how funfinder designs jaajii
http://www.youtube.com/watch?v=lIsNH...eature=related

I bet the major detector manufacturers are shaking in their boots.

[J_Player]

may be same built tegnologie how funfinder designs jaajii
http://www.youtube.com/watch?v=lIsNHMpEBYQ&feature=related

Hi Dman,
The video shows your detector really finds the metal.
Do you want to sell it?

¿Hola Dman, yo vi su detector de metales en el video.
¡Este detector discierne realmente metal!
¿Quiere vender este detector?

Best wishes,
J_P

[detectoman]

jajaja these detector isn of me, i show in example of rudimentary dm what semms how last genial design of me cousin funfinder

[detectoman]

how yours can see, these extrange cacharro, trashdesign has incredible extremely powerfull tx oscilador, but sound earing how reversed, to nearby contact difume disvanish this, may be need change any reversed transistor, or reversed ic, hehehe, btw these have an piece of enginering whit major tx oscilador versus scaner minelab, the design is an piece of art surrealist, how piccaso pictures or extremely poor man dream elucubration, be posible exibit these in outdoors?, remember this may first projects

[Funfinder]

Video Test Report

http://www.multiupload.com/H3AG7T6OWP

Yesterday finally the weather was fine so I could shoot the video. The plasticbag was hung on a bush after I rubbed it to my hair.

Detection distance is around 1m.

The unit received alot strange signals I couldn't always find out from where they came from. 300m away is a fastway and also a railroad.

But as you can hear in the second clip it also detects a helicopter. On the video it is perhaps just 400m distance, but I could hear it already much earlier - perhaps even 1-2km - directly and with the detector!

It sounds crazy, but it seems I received even some noises from a plane 3km above.

There also was nearby a very large iron object from an ex powerline-pylon fundament. I digged down 80cm a half year ago but left this solid with concrete connected stuff buried there. However, it couldn't detected.

And it made a huge difference how high I did hold the detector. 2m above the ground with reached arm the signals were "bombastic", while the border of detection are around 20-30cm above the ground.

It also made a big difference, if there were trees near or not (more near as 10meters).


Perhaps I'll publish the circuit for improvements because for now it seems not being capable detecting lta objects. But maybe there weren't just any near and iron does not working?


Actually circuit two should only became a very sensitive amp for the ferrite coil, but this still is not done yet.

I had no "concept" how those ferrites should distant detect metal so I focused on the sensitive receiver.

Well, I know how it would work, by very critical adjusted and powerful bfo - but I like to build some extra circuit for this. I guess at the moment the "pure" electrostatic detection still has to be modified.

Or the second possiblity: a long wave transmitting coil and a sensitive receiver where you can hear the frequency or modulation shift if some metal is near!!

It works already with the 100kHz wire-searcher transmitter circuit and some radio receiver but instead of the little ferrite antenna the transmitter should use a large coil. I have two of them, 1 works on 100kHz and the second with 150kHz - and the audible difference in FM reception seems better as AM.


I don't know if the mineoro detects plastic bags (I guess not!) but if there really is electrostatic involved at least it has to be even more sensitive - not only switching on or off style, but more slowly visible power or noise.

However, enjoy these absolutly authentic videos!


@ detectoman
the youtube md is IB design - it's called the "matchless detector" and completly different than mine. And the noise this homebrew makes is terrible!