Can pinpointer detecting thin chain?

[nakky]

Nakky

[Thomas]

Thanks Nupi, the voltage Sch. will be helpful for getting it just right.

[Nupi]

thank´s to both of you
I ordered some 3906 and then will try them out

With your parts must be able to detect but with the 2N3906, but he's a little less sensitive about 15% less.
Check all parts and compare them with the schematic.

Here are the voltage and components schematics.

[Nezocas]

thank´s to both of you
I ordered some 3906 and then will try them out

[Nupi]

TR1 should be a PNP 2n3906 or similar

You're right Thomas, it must be a pnp. Thanks!
Silly of me that it is not been noticed me.


Sorry Nezocas it's my fault.

[Thomas]

Hi
Mine didnt work. ( I made the NUPI Pinpointer ) NOT the mini one

I made some changes in some components, because local distributor didnt have them
I thought it would work, but, with lower results....but it didnt

Coil....same as yours
IC1 HEF4024BP
TR2 BD135
TR1 2N3904
C2 47nF cant find 33nF
C4 2.2nF



Also removed LED / Buzzer and R6 leaving only the micro-motor for vibration

Will try to find out why

Regards

TR1 should be a PNP 2n3906 or similar

[Nupi]

......
Will try to find out why Regards

Hi Nezocas,


Yes, I'd like to help you to find out why.


Don't worry.
We get anyway the pinpointer working properly.


I'm going to make a schematic with voltages points so that it can be compared.
Then, the problems are easier to find.


I do not think that the problem is the components you used but
tonight I check with yours used parts.


regards, nupi

[Nezocas]

Hi
Mine didnt work. ( I made the NUPI Pinpointer ) NOT the mini one

I made some changes in some components, because local distributor didnt have them
I thought it would work, but, with lower results....but it didnt

Coil....same as yours
IC1 HEF4024BP
TR2 BD135
TR1 2N3904
C2 47nF cant find 33nF
C4 2.2nF



Also removed LED / Buzzer and R6 leaving only the micro-motor for vibration

Will try to find out why

Regards

[Eugen]

Hi Nupi!

Already slit ferrite rod 3 piece 40 mm long.
Now I will be prepared in accordance with the original.
Therefore, it was not the only stable!

NUPI Thanks for your help!

[Nupi]

Hi,I'm not sure what you mean but I'll explain something.
It's not a "on and go" pinpointer.
But I have built a lot of them with a good stability.
I mean when you turn on for the first time, after 15 seconds it so stable
that you only every 2-3 minutes must regulate a little.

At my prototype expires after 3 minutes 4 Hz. That's not bad.
But now we are waiting for Davor.

[Nupi]

I say this to anyone who wants to build nupi pinpointer.
You are of course free to change the original circuit and got to experimenting.
That's interesting, fun and educational BUT you can not say Nupi pinpointer is not stable
if you deviate from the schematic and the components including the coil described.

success, regards.

[Nupi]

Hi Nupi!
Now I prepare for a coil like yours.
Maybe one ferrite can do?
The capacitors are changed.
Thank you!

Yes, with one ferrite works but you have to make the same number of turns as described.
It does not work as well as with three pieces.
You can use one ferrite rod of 10 cm to make a coil, break it into three pieces.

[Nupi]

Hi Nupi!
I made a test as well. This is the maximum stable.
https://www.youtube.com/watch?v=QYYu...ature=youtu.be

Nice video, but you have made NUPI acanary.
The detection is not correct.

Please look at the last part of the video.
There you can see good detection of a coin.

success

[Eugen]

Hi Nupi!
Now I prepare for a coil like yours.
Maybe one ferrite can do?
The capacitors are changed.
Thank you!

[Nupi]

Hi Nupi!
The coils 250/150 running 0.2 / 0.4 mm, ferrite 10mm x 800mm.
The capacitors C1 = 1nF (MKT) C2 = 10 nF (MKT)
R1 = 1K potm.
R2 = 100kOhm potm.
R3 = 2.2 Kohm potm. (1.65 Kohm a stable point)

Nupi Thanks for your help!

Hi, Eugen,
Now I understand why you had to change. R3
You had to make C2 lower because you're using another coil as mine and
you use in place of MKP the MKT. The best sensitivity and stability
reach you with exactly the parts which are on the schematic and the same coil that is described.

regards