SBG-PID

[waltr]

Yes, this is definitely discrimination based on target conductivity, and is why silver and large copper coins are also rejected because they have similar time constants.

Yep, an old method that uses conductivity or really the Target Tau.
Fe depending on size and shape can go either way.

[kt315]

are you under weed smoky? why your lines on schematic and board are so idiotically broken? why you are not able draw the lines right normally?
i can not look on your pics... no dwell... so GARBAGE always...

[6666]

Pulse induction motion detector.Ground balance and meter discrimination.Discrimination is possible best for PI detector with one coil.[ATTACH]46021[/ATTACH]

Thanks for posting.

[scs]

PCB.That's all I can give you.

[Qiaozhi]

Also ignores large objects, even pliers.The problem is that silver coins and some large copper coins are also indicated as iron.The discrimination depends on the mixing ratio of the two signals.The first signal is delayed 30 microseconds. The second signal is delayed 120 microseconds.The principle is in the picture.[ATTACH]46022[/ATTACH]

Yes, this is definitely discrimination based on target conductivity, and is why silver and large copper coins are also rejected because they have similar time constants.

[dbanner]

Please provide me with a LAYOUT if you have one.

[scs]

Also ignores large objects, even pliers.The problem is that silver coins and some large copper coins are also indicated as iron.The discrimination depends on the mixing ratio of the two signals.The first signal is delayed 30 microseconds. The second signal is delayed 120 microseconds.The principle is in the picture.

[Andi68]

If there is a layout, I try this circuit too.

I leave the faith to the religions

[dbanner]

Thanks for sharing the circuit. Very much appreciated.
I will be keen on building it for testing if only you can provide a layout.
How significant is loss of sensitivity when discrimination pot is turned up?
Can the circuit knock out bottle caps while still detecting some coins and silver and still maintain good detection depth?
Beaches here are infested with bottle caps so this circuit might be just fine if it can eliminate bottle caps.

[Qiaozhi]

Works like White's Electronics TDI SL Metal Detector .Well discriminates iron from gold, bronze, modern coins.Wrongly discriminates against thick silver and copper coins.

In which case it is using conductivity discrimination, the same as White's TDI. This is not ferrous / non-ferrous discrimination, and will only be able to ignore small nails of a similar size and shape. The same as waltr said in post #5.

[Artyom]

Your problem is whether to believe.

Who will believe empty words without evidence? Here I am telling you that with this device you can still find voids and drinking water. Distinguishes cleaned from dirty.

[scs]

Your problem is whether to believe.

[Andi68]

Then please prove that to us

[scs]

Works like White's Electronics TDI SL Metal Detector .Well discriminates iron from gold, bronze, modern coins.Wrongly discriminates against thick silver and copper coins.

[scs]

To wallker
You are writing nonsense so you do not fall asleep. This is quite different from a SBG -PI detector.Look and compare the schematics.