I was looking around on YouTube a week ago and I came across a Polish made PI machine, one without any form of PIC or computer, that appears to have quite a good range of detection. For example coins of about 2cm across detected at well over 35cm......that for me is deep!
Now I have found an Eagle copy of the schematic and the PCB, also an updated .pdf copy of the schematic, which has allowed me to update the .sch to what I believe is the latest version.
What needs to be done is someone (the more the merrier please) needs to work with me who can check the schematics as I am slightly sceptical of the power supply section, but that is not my strong point....
Naturally someone should also run an eye over the whole schematic for correctness and once that has been done, I could check out the PCB for validity.....
I do believe that I have enough to allow building, but I do not have the adjustment procedures for the two trimmers. One appears to be setting the duty cycle and frequency of the coil switching.
I calculated it out and the extremes of the pot allow for a duty cycle of between aprox 50:50 and 33:66, frequency between 2.2Khz and 32 Hz, all from one trimmer!!! I am not fond of a "Suck it and see policy" personally....but may have to do it that way in the end....
The other trimmer appears to set up the bias voltage for an op amp used to gate the signals picked up by the coil when on receive. That may be an easier set up to do by ear......
Anyone interested should check out the video on the various web sites that I will post below. Anyone who can speak the language is also welcome, but the machine translations are also quite readable....
http://www.lucaslab.grandhost.pl/luc...krywacz_PI.htm
http://tomek.ucoz.ru/publ/4-1-0-27
http://svv.my1.ru/publ/1-1-0-52/
The video can also be seen here:-
http://www.youtube.com/watch?v=V9U6fh2qeQI
In some places it says its a VLF design, that is false.....its a PI.
Welcome to anyone willing to help and participate in some way, but I am quite far away from actually feeling confident enough to start building.....
I tried to upload the files I have here, but it appears they were too big or something.....but most of them can be downloaded from the links I posted if you look around a bit.....
I will try and find a way round that......
Regards
Andy
Now I have found an Eagle copy of the schematic and the PCB, also an updated .pdf copy of the schematic, which has allowed me to update the .sch to what I believe is the latest version.
What needs to be done is someone (the more the merrier please) needs to work with me who can check the schematics as I am slightly sceptical of the power supply section, but that is not my strong point....
Naturally someone should also run an eye over the whole schematic for correctness and once that has been done, I could check out the PCB for validity.....
I do believe that I have enough to allow building, but I do not have the adjustment procedures for the two trimmers. One appears to be setting the duty cycle and frequency of the coil switching.
I calculated it out and the extremes of the pot allow for a duty cycle of between aprox 50:50 and 33:66, frequency between 2.2Khz and 32 Hz, all from one trimmer!!! I am not fond of a "Suck it and see policy" personally....but may have to do it that way in the end....
The other trimmer appears to set up the bias voltage for an op amp used to gate the signals picked up by the coil when on receive. That may be an easier set up to do by ear......
Anyone interested should check out the video on the various web sites that I will post below. Anyone who can speak the language is also welcome, but the machine translations are also quite readable....
http://www.lucaslab.grandhost.pl/luc...krywacz_PI.htm
http://tomek.ucoz.ru/publ/4-1-0-27
http://svv.my1.ru/publ/1-1-0-52/
The video can also be seen here:-
http://www.youtube.com/watch?v=V9U6fh2qeQI
In some places it says its a VLF design, that is false.....its a PI.
Welcome to anyone willing to help and participate in some way, but I am quite far away from actually feeling confident enough to start building.....
I tried to upload the files I have here, but it appears they were too big or something.....but most of them can be downloaded from the links I posted if you look around a bit.....
I will try and find a way round that......
Regards
Andy
Comment