Polish Pi

[surfdetector]

I have to say that this circuit does very well on the beach, I was able to find coins at over 10 inches deep. I move slowly over the sand and listen carefully for small increase in the "click click" sound. I was surprised at how well it worked, it is very stable at the beach where there is little interference. My coil is not shielded. I set the threshold for just about 1 click per second, there I have best results.

Hi,

I am curious as to the specs of your coil?
Cheers

[sbalio1]

hi
coil 95 cm


https://youtu.be/3zmpK4EqDuM

[surfdetector]

hi
coil 95 cm


https://youtu.be/3zmpK4EqDuM

Hi,

This video is listed as Private.

[Boadil]

Hi,

This video is listed as Private.

idem. Hi,

This video is listed as Private.

[Boadil]

[CITA = sbalio1; 267643] Para oro peque?o, los mejores cables son los menos gruesos
Tal vez su problema en algunas partes electr?nicas como bf245a (b * c) ... lf357


coil27cm oro peque?o
https://www.youtube.com/ watch? v = wWhOMBjqe7I

coil 32 * 37cm gold
https://www.youtube.com/watch?v=U_Xsg1nBsFQ

coil 65cm detecta 2.10 cm para un tama?o de 30 * 35
https://www.youtube.com/watch?v = ay6jltpWRao [/ QUOTE]

private video :no no:

[Boadil]

[CITA = karim1980; 266206] Etapas de fabricaci?n del detector de metales - polones pi

https://www.youtube.com/watch?v=x99O8YjvNE4&t=1s
enlace detector de polones pi pcb
https://www.mediafire.com/file/2bjqkl7q5o777z2 /PI_Polones_2019_information_section.rar/file [/ QUOTE]



thanks?????:s?per::s?per:

[6666]

[CITA = sbalio1; 267643] Para oro peque?o, los mejores cables son los menos gruesos
Tal vez su problema en algunas partes electr?nicas como bf245a (b * c) ... lf357


coil27cm oro peque?o
https://www.youtube.com/ watch? v = wWhOMBjqe7I

coil 32 * 37cm gold
https://www.youtube.com/watch?v=U_Xsg1nBsFQ

coil 65cm detecta 2.10 cm para un tama?o de 30 * 35
https://www.youtube.com/watch?v = ay6jltpWRao [/ QUOTE]

private video :no no:

PRIVATE VIDEO YES YES

[Andi68]

YES !

[surfdetector]

after assembling working detector its time for some mods
but i am not sure which direction, deep hunter for big objects or medium hunter for coins and smaller stuff

Did you complete any mods for this? I am curious how you might have changed the circuit.

Cheers

[Andi68]

The building instructions of the Sanbanks describe mods that also work with the Polish PI. You can also experiment with the component values.
I replaced BD911 with IRF740, for R6 I took 27 Ohm, the Mosfet needs more voltage at the gate.
You can also experiment with R1, this resistance determines the pulse width

[surfdetector]

The building instructions of the Sanbanks describe mods that also work with the Polish PI. You can also experiment with the component values.
I replaced BD911 with IRF740, for R6 I took 27 Ohm, the Mosfet needs more voltage at the gate.
You can also experiment with R1, this resistance determines the pulse width

What are the specs of the coil that you are using with this detector?

[Andi68]

For the test I made a coil, 16cm in diameter, 0.4mm enamelled wire, 32 turns, 1.6 ohms and 343 ?H.
I'm not really satisfied with that, further tests will follow.
In the Polish building instructions, a wire length of 16 meters is specified

[dbanner]

Forget about the 16 meters. That is only some general guidance.

To get the detector working optimum, put any coil with 250-300 uh. Then play with the pulse rate and damping value and any offsets.

[Andi68]

Yes, I thought the 16 meters might be too much

[gerson]

[QUOTE = Andi68; 268794] As instru??es de constru??o dos Sanbanks descrevem mods que tamb?m funcionam com o PI polon?s. Voc? tamb?m pode experimentar os valores dos componentes.
Troquei o BD911 pelo IRF740, pois o R6 tomei 27 Ohm, o Mosfet precisa de mais voltagem no port?o.
Voc? tamb?m pode experimentar com R1, essa resist?ncia determina a largura do pulso [/ QUOTE]

What values can be used for R1?
I made the changes you said and it works very well ..
I would like to try the exchange of R-1 to have a further improvement. Another problem I am having is instability. the tec .tec noise. tec. gradually gets accelerated. Someone has already managed to solve this problem.

Que valores pode ser usado para R1?
fiz as modifica??es que voce falou e funciona muito bem..
Gostaria de experimentar a troca de R-1 para ter uma melhoria a mais. Outro problema que estou tendo ? a instabilidade . o barulho tec .tec. tec. aos poucos fica acelerado. Alguem ja consegiu resolver este problema.