Doubt about the Polish PI

[surfdetector]

This is the PCB that we did. There is a pretty long thread on the German forum that Bernte and his group did of their build. I cannot find the link right now.

Here is the link to the PCB that we did. There are a couple of errors in it.

https://easyeda.com/jeanfreitas/pcb2-placa

[MOR_AL]

take this part from Sandbanks_ P J Wales, thats polish one in base. seek the sch/PDF from PROJECT subsection of this site.

Thank youkt315.
I was looking for one of the first Polish PI publications to verify this detail.
MOR_AL

[kt315]

.....

[Andi68]

He is talking about a circuit and does not show a circuit diagram where the relevant components can be seen.
This is nonsense for me
The simulation sucks, not the circuit

[MOR_AL]

My mistake!
No comment!

[MOR_AL]

He is talking about a circuit and does not show a circuit diagram where the relevant components can be seen.
This is nonsense for me
The simulation sucks, not the circuit

XXX_avt5196-1_ED.pdf
XXX_Det_Met_PI_Polon (.PDF)
(.JPG)

My simulation
XXX_Simulation.pdf
MOR_AL

[Andi68]

I suspect that the transistor behaves differently in the overall circuit than in the isolated simulation

[MOR_AL]

I suspect that the transistor behaves differently in the overall circuit than in the isolated simulation

Right! Your suspicions are well founded. We cannot ignore that many Polish PI assembled, are working.
I cannot explain this. But I noticed in a circuit, that transistor T3 was replaced by a current source. See Tr5 and Tr6 on the attached circuit.


Source:

https://pe2bz.philpem.me.uk/Comm01/-%20-%20Ion-Photon-RF/-%20Metal-Detectors/-%20BuildPlans/-%20Pulse/P-007-Sandbanks-PI/sandbanks.html

MOR_AL

[6666]

Right! Your suspicions are well founded. We cannot ignore that many Polish PI assembled, are working.
I cannot explain this. But I noticed in a circuit, that transistor T3 was replaced by a current source. See Tr5 and Tr6 on the attached circuit.
[ATTACH]54367[/ATTACH]

Source:

https://pe2bz.philpem.me.uk/Comm01/-%20-%20Ion-Photon-RF/-%20Metal-Detectors/-%20BuildPlans/-%20Pulse/P-007-Sandbanks-PI/sandbanks.html

MOR_AL

I have seen a published schematic that replaced the transistors with an opto coupler that drives the 555, it was very simple and apparently worked,

[bernte_one]

latest build for proof of working concept, the coil ist 1m above steel reinforced concrete wall
no drifting

https://www.youtube.com/watch?v=9xoKU-PuSe4

[6666]

latest build for proof of working concept, the coil ist 1m above steel reinforced concrete wall
no drifting

https://www.youtube.com/watch?v=9xoKU-PuSe4

[ATTACH]54448[/ATTACH]
[ATTACH]54447[/ATTACH]

Hello bernte_one do you follow any other forums to get information for new modifications on the polish pi ?

[bernte_one]

Hello bernte_one do you follow any other forums to get information for new modifications on the polish pi ?

this is the info i got from people of near east / orient

at moment they seem to have the most experience of building this cheap detector

[Andi68]

What is the purpose of the modifications?It's hard to see in the picture

[6666]

this is the info i got from people of near east / orient

at moment they seem to have the most experience of building this cheap detector

Thanks.

[samir3]

good