PICKINI V4 - an easy to build, self adjusting PI detector

[pigeon]

Ok My friend ..................Im Sorry..........Now its Ok??????

[ATTACH]37495[/ATTACH]

[ATTACH]37496[/ATTACH]

[pigeon]

Now it is OK, Arionas.
Nice work !

[Arionas]

[Tim]

F117, can you tell us the minimum delay available on this design with a fast coil? Will it be good for sub-gram native gold? Can it ignore mineralisation??

[BC547]

F117, can you tell us the minimum delay available on this design with a fast coil? Will it be good for sub-gram native gold? Can it ignore mineralisation??

With temporal sampling - as opposed to voltage sampling - there is no adjustable delay.
The width of the flyback pulse is measured - independent of how fast the coil is and how long the pulse lasts.
As for sub-gram gold and mineralisation: I haven't done any tests since the soil here is not to be compared with Australian gold fields. The worst case of mineralisation we have here is the wet beach. And yes, it works fine on the wet sea sand - as opposed to most of the IB detectors.

[BC547]

@Arionas:
no idea what you are trying to say with the schematic and the arrows ?
BTW: the direction of the yellow-red dotted arrow is wrong: pin 11 is the audio signal output. Your arrow suggest an input.
The direction of the solid red arrow on the schematic is also reverse: pin 10 is the comparator input.

- Bernard

[Arionas]

THE DESIGN I PUT WANT TO SHOW PROPER POSITION OF ELECTROLYTE FOR A FRIEND IN A PREVIOUS POST TO ASK

[chevesne]

Sorry Arionas, I should have put it in writing, saying that it seemed reversed capacitor to me.
Thank you again for your job.

[Tim]

Cheers F117. A bloody good job mate. I have the pickit3 & 16f's on the way-a steep learning curve coming up. I have the Newhobby NH5, an attiny 2313 based PI. And with a 260uH, 6 inch spiderweb coil, I can get about 4 inches on my 1.7g flour gold. I'm guessing that machine works on a similar electrickery (temporal sampling).
Got me wondering now about the possibilities of this temporal tom-foolery for a dedicated gold-finder in brutally mineralised ground....??
Sounds like something out of a Sci-fi movie. Could this be the technology to supercede lamebin?

[bernte_one]

i have tested earlier designs from pickini and they all can get Little Gold with a spiral coil made of litz wire 0,5mm, 2 layers each 20 turns, outer diameter 25cm

[Tim]

That sounds promising Bernte-Great to hear!! Should do well with my 260uH spiderweb coil too.

[bernte_one]

ok who is the first who make this work after Bernard, want to see a video

[BC547]

Apparently, nobody has made it working so far.

In the mean time, feast your eyes on some typical finds from the seaside dunes.
At first, I thought I had found a cannonball, but after digging 1m deep, it turned out to be a petanque ball.
Next: toy car, pull tab, aluminum French WW2 coin, tent peg,... lots of pieces of barbed wire (WW2 remains).





Have fun,
- Bernard

[nick holas]

hi bernard
how are you?
i made your detector with smallest pcb and i don t understand why it isnt working
i ve got the starup sound,the idle sound ,and after 30s (aprox) i have a continuous loud sound.
i must say i have changed the bc549 by bc547 and pot isn t 4k7 but 10k (my seller haven t it with switch in stock),and i m using 9v battery instead of 3x18650 battery pack,i have tested with 12v and no change at all!
any idea??
thanks

[BC547]

This means that after going through a complete calibration procedure of 30s, the flyback pulse is not detected and the coil error sound is what you hear.
It could be that the DC offset calibration fails ( no idea if the transistor type is so important here...) - or that there is no flyback pulse coming from the opamp output.
Can you verify the DC values that are mentioned on the web site:
http://users.telenet.be/willaert/MD/pickini/pickini_en/V4/electronics.html