IGSL

[golfnut]

Thanks,

Steve

[Jerry]

Very Nice! It took me several tries to get one looking that neat. Like the idea on the guide posts. I did something similar except it was just two walls which formed a corner for the frame to fit into .

What did you use for a frame to hold the plastic?

Nice looking shells.

Jerry

[ivconic]

How does it react to a large rusty chunk of iron, such as a horseshoe?

Seems Silverdog missed this?
I will try to answer instead.
Good question.
IGSL is performing excellent on such large irons in most of the cases.
It is producing both tones at the same time, same lasting, same decay.
But as i noticed; shape of large iron sometimes can cause a slice different sequence of tones.
If object is simple shaped than both tones appears equal.
If object is long and "slim" than audio sequence will depend on exact position of that object, related to coil position.
For sure; in both cases, both pitches will occur.
...
The other day, when i discovered that nice silver coin, there were two original Tesoro Vaquero's in "company" too. One "Germania" and one "USA".
So we performed few mutual checks.
Significant detail from that day, would be several times repeated situation; where Vaquero's clearly indicated "colored" item while IGSL indicated large iron (both tones at the same time).
So after digging .... IGSL was right!
Tough to claim anything, it is to early now, need more real tests to do.
But for sure; IGSL idea may turn as good step forward to solve damn "horseshoe" issue!

[ivconic]

In addition;
now.... i am plain amateur with very limited capabilities, so analogue approach is all i can do.
Would be nice to see IGSL idea transfered into "digital" area (two simple detectors in one, controlled by uPC).
Main goals would be accuracy, small sizes, smt and very low consumption (which is now the main issue at present IGSL; some 65-70mA) ....
and possible more benefits than i can name right now.
..
Referring the power drain; i was thinking to ask here about LP versions of some IC's.
LM339, LM883, LF347..and others.. are those having LP versions?
Can we calculate power savings if use LP versions?
I bet we can... but i would rather let somebody more conversant than me to do that...

[Qiaozhi]

IGSL is performing excellent on such large irons in most of the cases.
It is producing both tones at the same time, same lasting, same decay.
...
Significant detail from that day, would be several times repeated situation; where Vaquero's clearly indicated "colored" item while IGSL indicated large iron (both tones at the same time).

Because large rusty targets can give both a ferrous and a non-ferrous response, you will often see (or have experienced yourself) the case where you dig a large hole and find an old rusty horseshoe. This seems to happen with all detectors. I was wondering if it is possible with the IGSL to really distinguish between a coin and nail lying close together, and an old horseshoe?

Perhaps a new video is needed??

[ivconic]

Yes there is LP339....! One less to worry about!

[ivconic]

Because large rusty targets can give both a ferrous and a non-ferrous response, you will often see (or have experienced yourself) the case where you dig a large hole and find an old rusty horseshoe. This seems to happen with all detectors. I was wondering if it is possible with the IGSL to really distinguish between a coin and nail lying close together, and an old horseshoe?

Perhaps a new video is needed??

Yes that is the main question!
Most of the time operator (already skilled with IGSL) will easy hear difference in such possible audio sequences.
Yet there maybe rare situation where audio sequences from both cases will sound pretty same...
But hey.. nothing is perfect!
That's why i am in the middle of "heat" to upgrading it more...

[simonbaker]

In addition;
now.... i am plain amateur with very limited capabilities, so analogue approach is all i can do.
Would be nice to see IGSL idea transfered into "digital" area (two simple detectors in one, controlled by uPC).
Main goals would be accuracy, small sizes, smt and very low consumption (which is now the main issue at present IGSL; some 65-70mA) ....
and possible more benefits than i can name right now.
..
Referring the power drain; i was thinking to ask here about LP versions of some IC's.
LM339, LM883, LF347..and others.. are those having LP versions?
Can we calculate power savings if use LP versions?
I bet we can... but i would rather let somebody more conversant than me to do that...

Would be nice to see IGSL idea transfered into "digital" area (two simple detectors in one, controlled by uPC).

I have already started a project along those lines. However, I'm using the wrong uPC to do it right, but it will help me get started. Given my speed, I'm sure someone else will get there first. I bet Aziz has all the tools to do it in a week or two.

With uPC, you will not need two separate analog channels -- just sample the RX signal and everything else is done in software. Interpreting the signal can be done same as IGSL or any other logic you want. By adding some analog hardware, you can use a cheaper, less powerful uPC also, but less flexibility.

But is it fun? I think less, but has to be done anyway.

Cheers,

-SB

[ivconic]

"..With uPC, you will not need two separate analog channels -- just sample the RX signal and everything else is done in software..."

Ha! That's the part i don't like.
Because it's been already done that way, many times before.
Nothing new in such method.
No..what i meant is literally 2 blocks (2 channels each) separated as on IGSL.
Audio generation and appearance is a bit unsolved (yet) at IGSL.
I would try to implement uPC more in that direction... if i knew how!

[simonbaker]

"..With uPC, you will not need two separate analog channels -- just sample the RX signal and everything else is done in software..."

Ha! That's the part i don't like.
Because it's been already done that way, many times before.
Nothing new in such method.
No..what i meant is literally 2 blocks (2 channels each) separated as on IGSL.
Audio generation and appearance is a bit unsolved (yet) at IGSL.
I would try to implement uPC more in that direction... if i knew how!

That's another way to do it. But there is no true need because you only have one RX coil, so all the information is in the RX signal, whether you have 1 uPC or 10 uPCs. But practically, it might be easier with more uPCs ("channels"). If you use 1 uPC, you can still keep separate "channels" in software.

I'm playing with the MPS430 u-controller from TI. It is not really powerful enough to directly sample the RX signal. But it could easily sample the output of the LM308s and perform the discrimination and detection logic. That is one possibility I am considering. It might be possible to sample an earlier stage also, to reduce the parts.

We have plenty of work to do reinventing the wheel. Maybe invent a new spoke or two along the way...

Regards,

-SB

[ivconic]

That's another way to do it. But there is no true need because you only have one RX coil, so all the information is in the RX signal, whether you have 1 uPC or 10 uPCs. But practically, it might be easier with more uPCs ("channels"). If you use 1 uPC, you can still keep separate "channels" in software.

I'm playing with the MPS430 u-controller from TI. It is not really powerful enough to directly sample the RX signal. But it could easily sample the output of the LM308s and perform the discrimination and detection logic. That is one possibility I am considering. It might be possible to sample an earlier stage also, to reduce the parts.

We have plenty of work to do reinventing the wheel. Maybe invent a new spoke or two along the way...

Regards,

-SB

Call me "old school", call me "backward", call me whatever you like - but i still prefer more analogue approach than "digital" (whatever that may imply).
Why?
Analogue signal is ALWAYS carrying more informations than any kind of digital signal! (talking about md's)
You may sample it at any rate - still it will stay "sampled", if you understand what i mean...
Problem in processing analogue signal is not in how much informations it can care - but in accuracy and complexity of processing it.
That's where uPC's appear as more logical choice.
But still main fact will remain unbeatable: analogue signal is carrying much more informations! (md's...don't take this generally)
That's why i don't like much to think about "DSP".....at least not yet.
Another reason is because i am amateur and can not afford (nor have enough knowledge) to "play" more with it.
So, naturally, i am turned to think only about "analogue" solutions...
(i am sure some people will laugh much on this... but what can i do?)

[WM6]

Call me "old school", call me "backward", call me whatever you like - but i still prefer more analogue approach than "digital" (whatever that may imply).
Why?
Analogue signal is ALWAYS carrying more informations than any kind of digital signal! (talking about md's)
You may sample it at any rate - still it will stay "sampled", if you understand what i mean...
Problem in processing analogue signal is not in how much informations it can care - but in accuracy and complexity of processing it.
That's where uPC's appear as more logical choice.
But still main fact will remain unbeatable: analogue signal is carrying much more informations!
Always, ever!
That's why i don't like much to think about "DSP".....at least not yet.
Another reason is because i am amateur and can not afford (nor have enough knowledge) to "play" more with it.
So, naturally, i am turned to think only about "analogue" solutions...
(i am sure some people will laugh much on this... but what can i do?)

Quite close to (our) reality.
Is not the same in field of audio? No one digital approach can give us audio quality as an old tube audio device.
By analog detecting you need your brain to processing signal, by digital detecting you do not need your brain any-more all is still processed - you need only to believe in displayed data or not to believe.
But digital is not saying its last word, and combined solutions are possible too.

[ivconic]

To support my attitude explained in previous post;
ok, DSP is superior! Is it?
I have seen, tested and worked with majority of high end md's that are actual today.
If i name anyone of those - i can risk to provoke bedlam of opposite opinions, that's why i will not name neither one of those.
However, fact is i seen, tested and worked a while with majority of those.
Many of those are under "DSP" label (whatever that may imply! )
A pile of top electronics inside those machines! Latest technology! DSP! Blah, blah!
...
...
At the end of a day... results... average, not that superior over "analogues" !
In many cases much less than superior - "worse" would be the shortest description..
So? What we are talking about here?

[simonbaker]

Call me "old school", call me "backward", call me whatever you like - but i still prefer more analogue approach than "digital" (whatever that may imply).
Why?
Analogue signal is ALWAYS carrying more informations than any kind of digital signal! (talking about md's)
You may sample it at any rate - still it will stay "sampled", if you understand what i mean...
Problem in processing analogue signal is not in how much informations it can care - but in accuracy and complexity of processing it.
That's where uPC's appear as more logical choice.
But still main fact will remain unbeatable: analogue signal is carrying much more informations! (md's...don't take this generally)
That's why i don't like much to think about "DSP".....at least not yet.
Another reason is because i am amateur and can not afford (nor have enough knowledge) to "play" more with it.
So, naturally, i am turned to think only about "analogue" solutions...
(i am sure some people will laugh much on this... but what can i do?)

I feel the same.

Digital can be a quicker way to discover things, though. Like playing with filter constants, etc. It's like having LTSpice in your MD.

Just don't make me use SMT!!!

-SB

[ivconic]

I feel the same.

Digital can be a quicker way to discover things, though. Like playing with filter constants, etc. It's like having LTSpice in your MD.

Just don't make me use SMT!!!

-SB

I don't like SMT too.
But sooner or later we will have to try...
Circuitry will "grow" and expand in time, power drain will rise, pcb also....
So... hard compromise for DIY'er like me... will see.
SMT or not.. doesn't really matter , but power drain must be considered more seriously later, in time, as eventual upgrades appear.
Even now is to high; 65-70mA is way much for such device!
The other day i made VDI (although i said i will not) and connected it on IGSL.
It is working... and it is working nice.
So it is temptation to include it in final design.
Yet, overall power drain risen to 110mA !!! Without backlight. With backlight it can go up to 160mA (depends on intensity, which can be regulated via highwatt resistor)....
So...
one way or another... IGSL must be "rearranged" to carry more upgrades and remain "economical" !