Ebinger damping process detectors

[bernte_one]

Hello, I need all infos for Ebinger prinziple of damping process.

here is a short explanation

In the damping process, a high-frequency magnetic field (primary field) of low power is sent into the ground. As a result of the resulting eddy currents, a secondary field, which is superimposed with the primary field, forms from the metallic object. Since the primary field is opposite to the primary field and is less, this is attenuated (attenuated). By the electronic device of the device, the attenuation is converted into an acoustic signal and, at the same time, the primary field is amplified so that the energy loss is compensated. Primary and secondary field in active location methods However, the induction of the eddy currents only takes place as long as a relative movement takes place between the primary field and the interfering body. If the search coil remains in one place, the signal breaks down after a short time because, according to the working principle of the detector, the primary field is automatically amplified. The respective disturbance variable is thus adjusted. This means that metal detectors of this type have to be kept constantly in motion in order to locate an interfering body. One speaks of the dynamic search principle. In addition to this disadvantage, the damping method also entails certain advantages. When the detector is used in the immediate vicinity of large homogeneous sources of interference, e.g. Rail tracks, metal fencing, guard rails, or also supply lines, can be operated parallel to this background disturbance at a certain distance after compensation of the detector. The same principle can also be used when scanning surfaces

yesterday I tested a device with this process, results are better than every method I see before, better than pi (also compared with some pi detectors from ebinger) and also vlf
we also build a diy coil

coil is pi like and also easy to produce, but it is more resistance and more mH
5,5R and between 3,5 and 5mH (not µH)
we took around 80m of 0,5mm yv wire monoloop coil mit 16cm Dia

newer models are fitted in epoxy so I have no chance to get the circuit, but seems all without µcontroller
pcb design seems also classical hand drawn copper tracks (early 90s design)

[Skippy]

Is that machine-translated from German? It makes no sense at all.
"Since the primary field is opposite to the primary field" Whut?
Can you post the text in German, then maybe someone (not me..) can make some sense of it. ?

[bernte_one]

thats exact the meaning is that the secondary field has opposite direction to Primary field
http://www.arbeitshilfen-kampfmittel...ang_3.1.3.html

Primary field is damped by target field, the amount of damping is converted to accoustic Signal (also the Level- means rising tone in relation to strenght of damping value)
at same time the damped Primary field gets compensated so that you dont loss Performance


we tested it with a burned brick, it gives a short detection Sound but after this you can detect obejct behind this brick, tested with 1g Gold Piece and also mit 0,4g Nugget
objects are detect abled several cm behind the brick

only Thing i can Image by myself that it work like a compensated bfo
but that cant be so simple...? because it is very sensitive

[Bill512]

Hallo bernte, the TX way is pulses? like a typical PI?

[Davor]

The way I see it, you have a PI, and explanation follows it completely. Speaking of opposite field, yes, that's also true for coloured metals. Ferrites respond in (almost) in-phase, rising coil inductance, while coloured metals do the opposite, and more so with better conductance.
E.g. on moderate RF frequencies we use ferrite cores to tune a coil, and inductance grows as you screw it in. But on higher frequencies we use bronze cores for tuning coils, and the more you screw it in inductance gets lower.

[bernte_one]

no it is not a pi, it is also called sinus damping process

may be it is a type of a pulse oszillator (like teemos project) but much more powerfull
if have seen it, and all other models which are ebinger pi were much slower in reaction/ respond time
life tested it side by side

there are not much videos around from ebinger, next time i will make one

i read some patent writings from end of 90s and beginning 2000

first type was a bit like vlf detector we now
vlf works with frequency drift and amplitude change for separating and detecting metals

the first concepts of that damping process only care about the difference in amplitude
change of frequency was not important

in later models the added analyse of drift for metal separation/ identification

[Davor]

You may process PI signal exactly as you would VLF, and perhaps Ebinger realised that. Physics work the same for VLF and PI. If you are able to see what its Tx emits, we'd know what it does.
The drawing on a page you linked indicates PI-like Tx decay. If there was a step voltage excitation, you'd not have exponential drop, but straight drop.

Regardless of what they did, I hear they did a good job. Too bad they are very expensive.

[Teleno]

The way I see it, you have a PI, and explanation follows it completely.

It is not. I'm working right now on a detector based on this principle.

My explanation is as follows: The Tx coil forms a free-running oscillator whose amplitude is kept constant by a feedback loop. A conducting target increases the power drawn by the oscillator (transformer effect), which forces the feedback loop to readjust the amplitude. The readjustment is the signal you want to measure. The target also causes a frequency shift that can be used for discrimination.

[Davor]

Good luck with that.
I'm not saying you are doing anything wrong, quite to the contrary. I also see a few paths to try. Just because people before us did not succeed in some endeavours doesn't mean they'd fail if they had our resources.

[Teleno]

Good luck with that.
I'm not saying you are doing anything wrong, quite to the contrary. I also see a few paths to try. Just because people before us did not succeed in some endeavours doesn't mean they'd fail if they had our resources.

So far I'm very happy with results. I'll post some material soon.

[bernte_one]

no the picture with the decay curve, was next detection prinziple i mean next chapter, the clear divide each other
i search patent tomorrow then i can explain how the basic circuit works

[bernte_one]

https://www.google.com/patents/DE4212363C2?cl=de



The searching oscillator sensitive to damping of the Metalldetek of gate is trained as a LC circle and encloses a detector searching reel 1, one in parallel with this switched Konden sator 1a as well as other components which are provided symbolically with the Be train sign 2. The exit of the Suchoszilla of gate is connected to a rectifier 3 which generates a DC-Richtsspannung he from the amplitude of the searching oscillator. The Immediately or Richtspannung of the rectifier 3 is supplied to this connected at the outlet side amplifier 4 which is laid as a DC voltage amplifier or DC amplifier from. At the exit of the amplifier 4 a chip nungsfrequenzwandler 5 is connected by which it strengthened DC-Richtspannung in an acoustic signal umge strolls becomes which is returned over a loudspeaker 6 which is connected at the exit of the tension frequency changer 5.
In the present of leading-capable objects the amplitude of the searching oscillator sensitive to damping becomes smaller, and this amplitude decrease is indicated by the loudspeaker 6.


Moreover, by effect of leading-capable objects, as for example from metal or from Ferri's tables to parts, the company frequency of the searching oscillator changes. To the capture of the frequency change of the searching oscillator with presence of a leading-capable object a Frequenzvergleicher 8 is planned whose entrance with the searching oscillator signal beaufschlagt is which will transfer about a management 8a of the searching oscillator to the Vergleicher 8. The Vergleicher 8 generates inside a relation frequency and compares this to the frequency of the searching oscillator signal adjoining in the Vergleichereingang. A frequency rise (Δf), i. e. a searching oscillator frequency which lies about the relation frequency indicates the presence of a non-ferrous metal (metal), while the negative comparative result (-Δf) indicates the presence of an iron metal (Fe metal). At an exit of the Vergleichers 8 an optical announcement equipment 11 is connected which is laid out, for example, as a zero instrument and a pointer rash indicates the presence of a non-ferrous metal and a rash in the negative direction the presence of an iron metal in the positive direction.
Further a signal or frequency modulator 9 which is connected at an other exit of the Frequenzvergleichers 8 to the receipt of the comparative result from the Vergleicher 8 is planned. The exit of the modulator 9 is connected in the tension frequency changer 5 and steers his entrance, while in the equipment 5 generated acoustic signals with the modulation signal of the modulator 9 is modulated. For example, the modulator 9 is laid out as a frequency modulator and generates a tax tension as a function of the input signal whose frequency rises according to the result in the Frequenzvergleicher of 8 carried out frequency comparisons or drops. In this manner can be distinguished over the loudspeaker 6 acoustically between iron and not iron to metals.


Further information about the metal object grasped by the metal detector is reached erfindungsgemäß by a processing unity 7 which the searching oscillator frequency change with the searching oscillator amplitude change processes on account of the presence of a metal object. The processing being heit is trained in the shown implementation example as an Amplituden-/Frequenzvergleicher 7.
The Vergleicher 7 shows two entrances. An entrance of the Vergleichers 7 is with an exit of the Frequenzvergleichers 8 and the other entrance of the Vergleichers 7 is connected with the exit of the amplifier 4. The Vergleicher 7 is so laid out that he carries out a comparison of the tension level recorder at the exit of the amplifier of 4 enclosed signals (DC voltage signal) with a tension signal of the Frequenzvergleicher 8 which contains the frequency change with reference to the relation frequency. In the Vergleicher 7 the damping effect, so the amplitude change is compared to the frequency change in size and direction with each other. This comparative result is indicated about an announcement 10 optically which is connected to an exit of the Vergleichers 7 and is also laid out as a zero instrument.
For example, it comes with big searching oscillator to amplitude burglaries merely to low searching oscillator frequency changes. This behaviour typical for a certain object admits conclusions on size, material state and distance of the concealed object and a suitable evaluation is carried out about the Vergleicher 7 and is indicated by the announcement 10.
The announcements 10 and 11 offer in addition to the acoustic announcement 6 a fullness of object information which cannot be derived from the customary metal detectors which work after the damping principle or after the frequency change principle.

[Teleno]

It works as I thought:

http://www.ebinger.org/backataloge/eb450bdt.pdf

FUNKTION Ein freischwingender Oszillator, dessen Suchspule als LC-Schwingkreis ausgebildet ist, erfährt bei
Annäherung an Metall einen Dämpfungseffekt. Es entsteht eine Amplitudenänderung, die nach elektronischer
Aufbereitung in ein akustisches Signal umgesetzt wird.

A free-running oscillator whose search coil is built as an LC circuit, experiences a damping effect by proximity to metal. A change in amplitude occurs that's translated into an acoustic signal after electronic processing.

I've done some experiments on this mode of operation, see this thread: http://www.geotech1.com/forums/showt...447#post228447

[Teleno]

My "damping method" prototype. Keep in mind it has no amplifier, what you see is the raw signal digitally amplified.

[Nexus]

we tested it with a burned brick, it gives a short detection Sound but after this you can detect obejct behind this brick, tested with 1g Gold Piece and also mit 0,4g Nugget
objects are detect abled several cm behind the brick

There quite a few IB detectors that can do the same. I am curious to see what other advantage this method may have if any.