Does anybody Does anybody recognize this simple ATtiny PI circuit ? maybe Russian

[6666]

Does anybody recognise this simple PI circuit ?
I believe it may be Russian, trying to match the circuit to a website if anybody has a link, thank you.

[6666]

Found it

http://alex---1967.narod.ru/PI_metal_detector_shok_2.html

[homefire]

I have a copy of that here some place. Have a programmed IC not used stashed away too. Some Place ? LOL Found it.

Here's a Untested PCB I bodged up. You might give it a go.

[homefire]

Dhoooooo That PCB is for the MET FM Pic detector. Sorry.

[MartyJ1963]

Goes anyone know the Coil Data for this PI?,,,Thanks in advance, Rgeards, Marty

[kt315]

i see his email address there on the page
[email protected]
i hope he still lives...

[6666]

Thanks all PC. Has failed on phone

[6666]

Goes anyone know the Coil Data for this PI?,,,Thanks in advance, Rgeards, Marty

Any pi coil adjust damping

[MartyJ1963]

@6666,,,Thanks. Regards, Marty

[Captainart]

I built this one in the past. It is very sensitive in the air if you get it really close to threshold but this detector is ringing/oscillating on its own and needs to be calibrated pretty much every minute. I think I have video of it somewhere.

And here is the video. https://youtu.be/Sg1dT_T4AXY
It's either this one or one of the alex---1967 modifications. Most of them are ringing.

[Captainart]

I also did some testing and added dynamic mode to it to compensate for ringing but lost sensitivity dramatically. Any idea how to stop it from oscillating?

[dbanner]

Make other circuit. Op amp compensation. Maybe the op amp is configured too simple and has itself become unstable, and is the source of the oscillations.??? Maybe try close loop and limit the gain, I don't know.
Also, put decoupling caps on V+ pin of op amp. 470uF to ground and 0.1uF to ground. This is good practice.

[Captainart]

From my experience any simplified detector like this will have this problem. The stuff that was in original schematic was there for a reason. It is basically Pirate with bunch of stuff removed from it. It is still somewhat usable if you ok with pressing calibration button all the time. It would work great for pinpointer just for being so simple.