Can pinpointer detecting thin chain?

[viwaldi]

My nupi finally works I could not find a mistake for a long time. The contact board power supply was defective. The power supply voltage was very unstable. On the new power supply the nupi started working immediately. Coil on ferrite from the filter. Wire anyhow. Inductance L1 1.65mH and L2 did not even measure.
The coin is 1 Polish penny (15.3 mm brass).
If the coin is at the same coil - the nupi lose their voice. It looks like the signal was too big. So it has to be? Do you try to regulate?

https://youtu.be/FkTlnD6m8Oc

[Virdi_248]

I have managed to make it work. Replaced adjustable resistance of 1k for 100k and also I have changed cd4024 for the new one and now it works. The worse thing is the big size, in the future I am going to make other one small.


[ATTACH]39934[/ATTACH]
[ATTACH]39935[/ATTACH]

https://www.youtube.com/watch?v=OO_Dyu_5lew

Thank you

I have fulfilled another small pinpointer mas with my pcb sprint layout. I have proved it in rich land in very bad salt for detectors.

The result has been excellent, alone two times the pinpointer fits in four hours.

With the permission of the creator of the thread I put my pcb, the information of my own bobbin and some photo and video. In the video the pinpointer not this one in his maxim sensibility. I sit it for translation of the language.


Chip used
HCF4024

Thanks to all who helped me.
pp nupi pcb sprint layout.rar
Data coil.txt

https://www.youtube.com/watch?v=46Fiqvx5uEQ

[viwaldi]

@NUPI

Hello NUPI
Have you thought over the coil on the core of the filter? Such as the picture.
Robilem pinpointer minimax2 with such a coil. The lines were very similar to the dedicated coil.

https://youtu.be/1-01C7XvOn0

regards
viwaldi

--
translated from Polish by Google translator

[viwaldi]

Hello
Has anyone built an automatic nupi? I'm going to build a pinpointer and wonder which version to choose.

regards
viwaldi

--
translated from Polish by Google translator

[Funfinder]

Some news from the real metal-detecting world!
btw. a thin chain is huge compared to this here:



which I found with the Makro Racer with 28cm coil plus modified Garrett Pro Pointer.
Its a record - the smallest handmade nails I have ever found so far!
Besides: Everything detected by vibration - size ca. 7mm.

Without modified pinpointer - no chance!
I had spread just a little bit of the soil super flat over my hand and
it took me over 30 seconds to find out with the PP where the metallic thing is hidden.

[ripsdevala]

Many thanks

[blobber]

Here are my files, as you can see with some modifications. The ferrite rod is 8 mm diameter and 60 mm long. Power supply with LM317.

Nupis PP_mod blobber.zip

[ripsdevala]

Nupi's pinpointer in homemade water proof enclosure.

https://youtu.be/nB_lOlpI7Vk

Are u using layout from nupi author? I was working on this before, but not working.
Let me try chemelec layout, anyone have the sprint?

[Virdi_248]

I have managed to make it work. Replaced adjustable resistance of 1k for 100k and also I have changed cd4024 for the new one and now it works. The worse thing is the big size, in the future I am going to make other one small.

https://www.youtube.com/watch?v=OO_Dyu_5lew

Thank you

[blobber]

Nupi's pinpointer in homemade water proof enclosure.

https://youtu.be/nB_lOlpI7Vk

[Polymer]

Not Sure it is more Robust, But it works for me.
Mainly it gives a fairly fine Tuning Without the need for a Multi-turn Pot.

My Ferrite Rod is Embedded in a 1/2 inch Diameter ABS Rod, than Lathed with a Groove where the Coil is to be wound.
And I Wind all my coils on my Metal Lathe, at Quite High Speeds.

My Modified Schematic:
Depending on the Coil Winding, the 68K Resistor Might Need to be a Higher Value.
[ATTACH]39670[/ATTACH]

Thank You so much Chemelec. I will be trying this soon.
Your circuit may open the possibilitiy of using NTC/PTC for partial 'automatic' temperature compensation.

It's great you have a lathe. I hand-wind these things. Talk about ZEN meditation.

[chemelec]

Nice re-design Chemelec! I assume your bias design is more robust (temperature wise) than the NUPI one.
If so, please post a schematic.
I can't test circuits quickly on a breadboard, because I live in a humid & salty environment causing lots of contact problems, so I have to solder everything.

Not Sure it is more Robust, But it works for me.
Mainly it gives a fairly fine Tuning Without the need for a Multi-turn Pot.

My Ferrite Rod is Embedded in a 1/2 inch Diameter ABS Rod, than Lathed with a Groove where the Coil is to be wound.
And I Wind all my coils on my Metal Lathe, at Quite High Speeds.

My Modified Schematic:
Depending on the Coil Winding, the 68K Resistor Might Need to be a Higher Value.

[Polymer]

I want to show a photo I'm not home for two days. If I have in my phone a capture of the tracks created, I have mounted the circuit.

Just saw your coil. Like Chemelec & others say: take your time winding the coil really well. I use double-sided sticky tape layers to make this easier.

[Polymer]

I just used Polyester Caps.
And a Slightly Modified Circuit, Works Good.
(My Ferrite Rod is just a 1.5 inch Long and 1/4 inch Diameter.)

[ATTACH]39660[/ATTACH]

Nice re-design Chemelec! I assume your bias design is more robust (temperature wise) than the NUPI one.
If so, please post a schematic.
I can't test circuits quickly on a breadboard, because I live in a humid & salty environment causing lots of contact problems, so I have to solder everything.

[chemelec]

Does it have problem with temperature changes or when turn to the sky to 45" angle? need frequent adjustment? Mine had some issues. it has very good detection distance and sensibility to small targets but is not stable. I want to built one stable pinpointer, just on/off switch, with medium detection just for coins. but i'm stil searching.

As with most Pin Pointers it does need Minor adjusting for Greatest Sensitivity.