felezjoo PI(the best pulse induction metal detector that I made until now)

[koohyar]

Hello dear friends
Today I want to talk a little about the system settings, especially the Sensitivity setting and coil calibrating for best results.
If you have done the exact assembly and turn on the system without any problem, then, do the LCD contrast settings. And the system starts to work.
Like the below image

In the picture above you see on the screen that displays a summary of system settings.
The first line of a question mark, indicating the number of VDI.
And when the system will sense something instead of a question mark, a number from 1 to 99 displayed.
The letter S stands for sensitivity. And the number after it, the amount of sensitivity that is a number between 1 and 20.
The letter D stands DELAY and number later also show the amount of manual delay.
The letter F stands for frequency, and the number after that displays the set frequency.
The letter p stands for the pulse with. And then also the number it shows.
Next in line is the dark line represents the balance of the system and if the system is in this case an exclamation point! Show, indicating the presence of holes
Go out right on the screen, the battery indicator that shows the battery voltage.

In the following
In this case, if you press the up button once.
You can see the number of debug or the number of integration, such as the image below.
This number can provide information about the type and size of the metal sense to you. Of course, if enough experience in this field, have won.


And if you press the up button, for the second time, you have three numbers on the screen, you see, as
shown below.



These numbers are very important. And indicates that, Op-Amp is the original, and system health.
These numbers, called numbers separate channel.
To separate operation, properly done, and iron removal be done carefully. Note that these numbers should be close to (300,700,800).

In the next picture you can see the options in the menu.
Using the up and down keys, you can switch between options. And using the left and right keys, you can change the desired options.

In the next post I will try to pay close examination of menu options, and how to fine-tune these options, explain.

[Funfinder]

thx koohyar for the info and some 60cm-70cm coil always is super and should became standard for deep-search!



Of course someone can (and in this case: should) use a socket for the chip so its removable and reprogrammable.
(don't set the write-protected fuse to on)

And if the gold-containing Aussie-soil really is such ultra heavy mineralized I would use
a non-motion VLF detector with very small coil to get good discrimination for the small nuggets -
at least at areas full of iron junk.




btw. seems there runs not everything perfect at this iranian forum:

this here was posted at our LRL-forum:

http://www.longrangelocators.com/forums/showthread.php?t=19104

subject:
felezhoo.com
04-19-2015

hi dear friends
i want to talk about an iranian forums "www.felezjoo.com"
is someone that know about this forums adminstrators? because i heard they are very dishonest and deceitful. their names are .hamid (حمید) and mojtaba (مجتبی)
They sell a treasure finder fpl-35 called for people who have bought it are very unhappy.

[6666]

As promised, here's the schematic. If you spot any errors, please let me know and I will correct them.
I've also included a PCB overlay with the components and tracks combined.

I guess we'll soon know how well the "iron reject" feature functions, and whether it's capable of working with Oz soil conditions.
It would be interesting to test the claimed ability to detect small gold, as the huge gain in the preamp should be a barrier to sub-10us sampling.

THANKS Qiaozhi, much appreciated, this will be a long term project, and depends if I can manufacture the pcb.

I would like to discuss R5 which is 2.2k , I've seen similar ccts, with the resister being as high as 10K such as the Skif PI
what concerns me a bit is that circuit configuration will dump the 12v onto the gate of the IRF840
but wont the high value of resistance 2.2k (up to 10K) limit the current into the gate and not fully turn
the fet on ?

[6666]

Hey guys
I have prepared a PDF for you, which is a description of the system and its performance.
I hope to be useful.

Thanks for the PDF.

[mohandes]

one thing is more important and it is your coil. 0.7ohm and 350mkh.for each coil you have 3 number that you can see in the LCD,and you should check it by that.your number should be near of those numbers.if your number ok so you success.

[Qiaozhi]

well done
but designer tell in Iranian forum can set TX power to 400mks.and about PPS too can adjust.
but the important part is reject iron.
regards

If you have built this detector, can you please tell us how well it rejects iron? Can it do this for different sizes and different shapes?

In your notes its says:
"Iron Reject: (iron removal) This setting is similar to the GPX Minelab series , And by a complex formula of iron diagnosis, is done."

But ... the Minelab GPX uses Multi Period Sensing (MPS), Dual Voltage Technology (DVT) and Smart Electronic Timing Alignment (SETA) ... and I don't see any of these in the schematic. The GPX is also designed to find sub-gram nuggets, which requires sub-10us sampling. With the preamp gain set to 80dB (and a 380uH mono coil) there is absolutely no possibility of this happening in this design. I'm sure the software is using some novel techniques to try and extract target information from the input signal, but [like all PI detectors] you cannot extract information that's not there. Although you can do some clever manipulation of the sampled data, any so-called "iron rejection" will still be based on target conductivity, so it's never going to be anything more than an educated guess.

Of course, I stand to be corrected, and look forward to 6666's findings.

[mohandes]

As promised, here's the schematic. If you spot any errors, please let me know and I will correct them.
I've also included a PCB overlay with the components and tracks combined.

I guess we'll soon know how well the "iron reject" feature functions, and whether it's capable of working with Oz soil conditions.
It would be interesting to test the claimed ability to detect small gold, as the huge gain in the preamp should be a barrier to sub-10us sampling.

well done
but designer tell in Iranian forum can set TX power to 400mks.and about PPS too can adjust.
but the important part is reject iron.
regards

[mickstv]

From the pictures I posted at the link below, everyone can see how bad mineralized soil is and thats only with a preamp of 100x.

http://www.geotech1.com/forums/showthread.php?22540-GEB&p=206531#post206531

[Qiaozhi]

HI Qiaozhi,

With gain like that on the preamp, I can tell you it definitely will not work here in Oz..

Cheers Mick

That was exactly my thought as well, but the claim is that this is a PI detector to suit all conditions, and with iron reject.
We shall see what we shall see, as soon as 6666 has built a copy for testing.

[Mechanic]

HI Qiaozhi,

With gain like that on the preamp, I can tell you it definitely will not work here in Oz..

Cheers Mick

[Qiaozhi]

Hey guys
I have prepared a PDF for you, which is a description of the system and its performance.
I hope to be useful.

Thanks kooyhar.

[Qiaozhi]

Just ordered a ATmega328P-PU for this project a schematic would be usefull.

As promised, here's the schematic. If you spot any errors, please let me know and I will correct them.
I've also included a PCB overlay with the components and tracks combined.

I guess we'll soon know how well the "iron reject" feature functions, and whether it's capable of working with Oz soil conditions.
It would be interesting to test the claimed ability to detect small gold, as the huge gain in the preamp should be a barrier to sub-10us sampling.

[WM6]

Hey guys
I have prepared a PDF for you, which is a description of the system and its performance.
I hope to be useful.

Excellent work koohyar.
Thanks to deal with us.

[koohyar]

Explanation of some questions

In response to common questions such as whether the detector is sensitive to salt or clay? Or how is sensitivity to the gold? Or how does this work by a big loop? Or even what kind of loop in this circuit there?
I must say, basically the questions about this particular design is almost meaningless!
As already mentioned with regard to all possible options, virtually no special factors in the common pulse detector and not be changed by digital setting device.
Note that the sum of the settings of the device if you wanted to be an analog circuit requires at least 10 volume and perhaps as many more IC, and in no time, as well as digital system did not work!
But in this project, in fact, with any digital set of simple settings, we have a new metal detector, which will feature different.
With a range of settings, sensitivity to salt is extremely low.
And other settings, is much more sensitive to gold.
As well as the maximum sensitivity to metal, or the depth of the soil, all with the settings are changed.
So the plan is completely flexible, a perfect alternative for the thousands of design, which is a special feature.
And provided that, depending on the needs and tastes of the operator can get the desired response.
tnx

[koohyar]

Hey guys
I have prepared a PDF for you, which is a description of the system and its performance.
I hope to be useful.