felezjoo PI(the best pulse induction metal detector that I made until now)

[eclipse]

Folks, I have enough boards so you don't need to reserve or anything like that, so no worries, especially when it's not tested yet, so I don't know if it's error free.
I will publish the result when I'm ready.

[pedrete]

Me too, thanks.

[6666]

Hi Eclipse
I would be interested in buying a PCB, thanks.

[eclipse]

Low dropout regulator will do well here. For example lm2940c-12
It will have 0.2V~0.3V @150mA consumption dropout voltage so if you have 4xLi-ion batteries 3.7V each when fully charged their voltage is (4x4.2V) 16.8V
When discharged their voltage is ~3V (4x3V) 12V and with the help of the low dropout regulator such as lm2940c-12 you can fully use their charge,
looking at the datasheet it has the same pin configuration as the 7812. There are battery charging boards for 4 cells @ around 5$ so...

[eclipse]

Thanks for the input. I think the method you're using sounds good but it's not applicable for LI-ION batteries (too low voltage when discharged, down to 8V from 12.6),
maybe you're using lead acid battery, how the device performs when batteries are discharged?

On the other hand if you use 7812, the lowest input voltage it can handle as mentioned is 12V + 2V, so that leaves 5x3.7V LI-ION, and this maybe too bulky if you use 18650.

Instead of LF357 you can use also try LF356, AD744 (on papers it looks best, and I'm sure it will work)

[turboaleks]

I have completed this detector. The detection of coins with 300uh coil was deeper than with my MPP. I had no lf357 and so used a tl081 so the required parameters ( 200, 300, 700) don`t match for discrimination but generally the detector works stable. There was no need to power the device with 18 volts and that`s why i left out 7812 (bridged in and out) and used 12v accu. Photos and videos to come this weekend.

[WM6]

I do have extra boards, but I would prefer to test it and make sure it works.
.

Agree. Awaiting on your test results.

[eclipse]

I do have extra boards, but I would prefer to test it and make sure it works.
Price will be around 8$ + 3-4 $ for shipping.

[WM6]

Hi eclipse
do you have some surplus of this PCB?
If yes, what is your calculation to sell one?

[eclipse]

Here are some photos of the PCB, I received it just now. It's not exactly as the reference design (changed it a bit).
Hope the rest of the parts come before the end of the month to try this thing out see if it works.

[koohyar]

You have included the wrong schematic in your rar file. The original had a couple of errors.
This is the correct one:

tnx Qiaozhi

[Qiaozhi]

hi
tnx
you can download from here

You have included the wrong schematic in your rar file. The original had a couple of errors.
This is the correct one:

[koohyar]

hello koohyar,

many thanks this looks good

one attachment is not valid
if possible you can upload the files as zip Container this should work
the Pictures are fine very interesting

hi
tnx
you can download from here

[WM6]

one attachment is not valid

Has gone.

Here you are - rename TXT file to HEX:

http://docdro.id/8LkVahu

[bernte_one]

hello koohyar,

many thanks this looks good

one attachment is not valid
if possible you can upload the files as zip Container this should work
the Pictures are fine very interesting