GROUND BALANCE ( without the ground :-) )

[boilcoil]

Wonderful explanation, thank you.

[moodz]

Hey Paul, any ground balance reduces the sensitivity of the detector, and you have fixed the worst case (maybe to balance the lighter ones as well).
But if you have not provided for a lighter ground balance, does this mean (according to your calculations) that all balances of light and heavy soils lie in same zone?
This is important to not lose the detector's depth.

Good question ... so what is happening when you "pump" the coil over a ground on some types of commercial detectors ? You are effectively varying the ground intensity by changing height of the coil above the "ground" from heavy( low height) to light ( high height). In this type of detector the GB has to be set so it can accommodate the particular "curve" of the GB response ( some refer to a log linear response ) and hopefully the GB remains balanced.

But what if there was a particular data point where a key parameter of the GB response was zero and a target response if present is also known at that point ? If the ground curve is different for many types of ground but is still zero at a particular point ( could be time could be amplitude .... could be something else LOL ) then knowing that you can solve a bunch of simultaneous equations for the zero point ... thus effectively cancelling practically all grounds despite them having different response curves (viscous etc ). So solving for the "virtual ground" solves for all other grounds.

Of course we are talking in the magnetic domain here .... not conductivity ... that introduces another factor.

Does my method result in less sensitivity .... yes it does and here is why.

You may not agree but the way I look at it is that "all" targets ( including the ground as a possible target ) have a target "T" component and a Ground "G" component. Good conductors have mostly T component .... Ground has mostly G component.

If you have a target like a flaky gold nugget embedded in clay and quartz .. then it will have a maybe 20% G component and a 80% T component ... in the unbalanced ground detector both components will produce a response. The GB cuts the G component so the response drops because the T component is now the only detected signal.

I have tried to make this a very simple explanation. The solution is neat ... the maths is not.

[boilcoil]

Hey Paul, any ground balance reduces the sensitivity of the detector, and you have fixed the worst case (maybe to balance the lighter ones as well).
But if you have not provided for a lighter ground balance, does this mean (according to your calculations) that all balances of light and heavy soils lie in same zone?
This is important to not lose the detector's depth.

[moodz]

I think it is how output valves are matched to loudspeakers. I mean in the design of the output transformers.

in a broad sense … a driving impedance can “see” a load impedance and vice versa.

[moodz]

But what happens to your method if you change coils. Your algorithm will adjust? Or it doesn't matter.

….. still works. Do ground conditions change if you change coils? Ground is ground whether it’s virtual or real.

[dbanner]

But what happens to your method if you change coils. Your algorithm will adjust? Or it doesn't matter.

[dbanner]

Reflected impedance refers to the impedance as it appears from one side of a circuit to another due to the coupling of two circuits, particularly in transformers. It's essentially the impedance of a load connected to the secondary side of a transformer, as seen from the primary side.

I think it is how output valves are matched to loudspeakers. I mean in the design of the output transformers.

[dbanner]

I sometimes like to string a few "catchy" terms together in order to sound like the real deal. I haven't got a clue what's really going on.

I've noticed a lot of papers being published with outrageous claims, but it all sounds so nice.

You're the real deal.

[moodz]

The algorithm is extracting one of the components and is automatically rotating the phase in a third channel. This only happens when you wave the target, so it is a GB mode that is initiated when you press the button to ground balance.

It's just a guess.

This implies a virtual(imaginary) channel is used when this mode is selected.

Your right about one thing ... your theory is a guess
Thanks for all the kind comments regarding the "grey box" prototype ... not quite a black box prototype yet.

A key element is the inclusion of a virtual ground by means of forcing the search coil to "see" a really bad ground all the time ....

How is this done ?? ... well you could do it by including a "ground" eg filling the RX coil casing with ground type material ( ferrite dust / hot rocks etc ) .... however this is not efficient and the TX / RX field would be distorted.

However I dont do that ... its not what you would call an "elegant solution"

The "elegant solution" uses reflected impedance ... A ground that needs balancing out appears as a complex impedance in the RX signal.

Reflected impedance refers to the impedance as it appears from one side of a circuit to another due to the coupling of two circuits, particularly in transformers. It's essentially the impedance of a load connected to the secondary side of a transformer, as seen from the primary side.

By arranging a complex impedance that represents the worst possible ground ( eg lossy / viscous / ferrite ) to be in the signal path from TX to RX and using the principle of reflected impedance .... the real world "actual" ground would have to be extremely bad in order for this GB method not to overcome it.

Because the detector "sees" this bad ground all the time the detector can be be "prebalanced in air" without an actual ground signal.

This is a key claim in both PP patents.

I will know if someone is probably violating the patent simply by them claiming they can ground balance their detector in air.

Because I dont encumber the coil with this "reflected impedance" ... there is no need to prepare special coils ( I use a commercial coil to demonstrate this ) This also means target signals are not impacted.

My actual ground balance method ( code method ) is also new though in that auto correlates the near to the optimal ground balance .. much more effectively than other methods ....so its another claim in the patents.

P.

[moodz]

see next post

[dbanner]

The algorithm is extracting one of the components and is automatically rotating the phase in a third channel. This only happens when you wave the target, so it is a GB mode that is initiated when you press the button to ground balance.

It's just a guess.

This implies a virtual(imaginary) channel is used when this mode is selected.

[Riss]

One advantage the practitioners of pure mathematics have over the experimenters is that they hold no prior biases. They like to play with equations every which way until something pops.

And to think this came to you in a dream!

Good luck on the field tests, I expect you will find gold.

Many scientific discoveries, musical compositions and great ideas have come in dreams - then the brain works differently... let's wish Moodz "the force" would suggest to him in his dreams a place with many gold nuggets

[JoyJo]

The work is done grandly! My respect! And yet, judging by the size of the coil, I can assume that in a littered area, where there are many metal targets nearby, there may be problems with the search. For clean places to search for gold nuggets, this will be a great option.

[boilcoil]

Hey Paul, I expect you to show a bag full of gold, (of course and a few larger pieces).
Good luck and success.

[Riss]

Congratulations Paul! I'm curious what would happen on the monitor screen (and the sound indication) if the stone in the video passes 1-2 centimeters from the probe? What would happen if a stone and a piece of ceramic ( ceramic dust should stick to a neodymium magnet) at a distance of about 5-10 cm passed sequentially about 2 cm from the probe? This happens quite often when working in the field in Europe. Such videos should always show how strongly the stone sticks to a standard neodymium magnet from a hard disk. For example, from what distance a magnet placed on a table will jump to the stone (a rough measure of the magnetic permeability of the stone). All the improvements in cutting the ground are wonderful, but I have repeatedly been to fields with a cultural layer over one meter. there the soil has extremely high active losses – high conductivity + ashes from hearths (fireplace ) + organics + slags. This terribly reduces the real depth of target detection- the soil is terribly "noisy". The prototype has too many “buttons” - 4! A colleague told me that his client said, “I want a detector with two buttons – one for starting and one for stopping.”