New Project - MPS PI - Iron discriminating metal detector.

[algan]

Maybe if there were two channels on the disc the discrimination would be achieved in a different way.

[phred01]

Hello Phred01,

If you were to create your own PCB, you could freely choose the size of the board. With the original, you can't shrink the board by 2 mm on one side, but you could expand it by about 12 mm on the other side to reach a width of 100 mm.

What specific size do you need? And what enclosure do you want to use? For example, if you want to use a Hammond 1455 series aluminum enclosure (160 x 103 x 53 mm), you'd have to reduce the size by significantly more than 2 mm on the long side to fit, or add 12 mm on the short side of the PCB. That would be much easier.

Tried KiCad Problem auto routing works for very very simple pcb's This is circuit is fairly complex and requires manual routing which will become a major project in itself. DFBowers did a monumental job in doing the layout by hand.......don't want to re-invent the wheel. I have come up with a simple solution use a 100 x 200 blank board and mount DFBowers pcb with 4 nylon screws and nuts. BTW come across very cheap 200 mm x 100 mm Al extrusion enclosure @ a cost of 50c Will post pix's when done.
Found a possible issue mounted 2x 56nf caps found plated thru' holes are a bit tight! waiting for my order of parts to come from Futurlec

[Infamy]

A question for the Geotech community.. What would make this project more attractive or increase interest? What might impede hobbiests from undertaking this project?
Don..

In general interest terms from my point of view, I will tell you straight. In about 2003 I spent a morning detecting with Dave Emery the inventor of the Pulse Devil, 22 years on I think things have not moved on much.
My philosophy by necessity is to record analyse and record again using different detectors. My background is in GPS surveying from that experience I think postprocessing, build data bases, analysis and even AI is where you have to go if progress is to be made. I can build a high precision GPS postprosseing system for under $300 and a programmable GPS navigation system for between $500 - $1000 for semi autonomous work. In a way this is like going from single item production to mass production. I posted a proof of concept on DIYDrones in about 2008 - 2009 integrating GPS guidance, datalogging with a detector and I know OKM had a basic sort of system before that. Minelab took out a patent in 2012 on a basic GPS detector, something that was already in the public domain; nothing new there. Since then I have seen no evidence that any one has pushed this idea, basically its still swing dig. So much the same nothing new.



Specific to your project, has to operates effectively in mineralized ground. Unless it can do that the Minelab Sovereign is always going to be better and thats decades old.
Too similiar to the VooDoo project may be a problem as there is a book on that project.

If you really want to push this project make up kits and produce a booklet to go with it. The biggest barrier to any of these projects is sourcing the components and good instructions.

[Olly]

Tried KiCad Problem auto routing works for very very simple pcb's This is circuit is fairly complex and requires manual routing which will become a major project in itself. DFBowers did a monumental job in doing the layout by hand.......don't want to re-invent the wheel. I have come up with a simple solution use a 100 x 200 blank board and mount DFBowers pcb with 4 nylon screws and nuts. BTW come across very cheap 200 mm x 100 mm Al extrusion enclosure @ a cost of 50c Will post pix's when done.
Found a possible issue mounted 2x 56nf caps found plated thru' holes are a bit tight! waiting for my order of parts to come from Futurlec

Auto routing of boards with noise-sensitive analogue sections is never a good idea. A well designed hand routed board is always going to work better...

[phred01]

My cheap enclosure with board adapter Piggy backing pcb onto blank 100mm x 200mm single sided board see pics

[phred01]

Hi DIY's and Home Brewers
Finally got majority components from Futurlec Miss-ordered a few parts like LM 393 ordered LM 339 instead which is 14 pin quad version .....bit hard to squeeze into 8 pin socket.......... pcb 90% loaded . Updated the material regarding minor capacitor quantity didn't check the resistor quantities. Found very hard to stuff the board from the screen overlay It would have been better have component id like R1.... C1.... IC1..etc cross reference to the cct diagram plan to do this soon

[phred01]

Hi all
Still checking on differences between material list & the cct. The reference diode for the battery test in the cct 1.09 and 1.22.1 & pcb overlay show 7v yet the parts list calls for a 9v zener Which one to use?

[algan]

Hi all
Still checking on differences between material list & the cct. The reference diode for the battery test in the cct 1.09 and 1.22.1 & pcb overlay show 7v yet the parts list calls for a 9v zener Which one to use?

You can use 10 volts or 11 volts to test the battery.

[GeoMax]

Hi phred01,

You can basically use any voltage between 7V and 11V. The selected value determines when the battery voltage reaches that level, signaling to the user that the battery is low.
I would probably choose 9V.

[Detectorist#1]

Hi phred01,
As GeoMax mention, the selected value of the Zener voltage depends of reasonable level of the voltage when the battery is close to the end of energy. For different type of the battery, the reasonable end voltage is different. For 8xAA alkaline batteries, end voltage is 8V and 7V (6.8V nearest standard) Zener voltage is suitable. For 12V Lead battery, 11V end voltage is suitable and Zener voltage of 10V is OK. For 3xLiPo accus, 9V end voltage is normal and 8V (8.2V nearest standard) Zener voltage is OK.

[pechkata]

Здравей phred01,
Както спомена GeoMax, избраната стойност на ценеровото напрежение зависи от разумното ниво на напрежение, когато батерията е близо до края на заряда си. За различните видове батерии, разумното крайно напрежение е различно. За 8xAA алкални батерии, крайното напрежение е 8V, а 7V (6.8V най-близкия стандарт) е подходящо ценерово напрежение. За 12V оловна батерия, крайното напрежение 11V е подходящо, а ценеровото напрежение от 10V е добре. За 3xLiPo батерии, крайното напрежение 9V е нормално, а 8V (8.2V най-близкия стандарт) ценеровото напрежение е добре.

Много объркващо мнение



A 9 volt zener diode would be great.
For 12 volt battery.
.