Simplest PI detector possible?

[6666]

Dfbowers
Don how do these simple schematics compare to your draw full of "simplest PI s "?

[Eddy71]

Can anybody please tell us what a K157UD2 is ?

It replased by LM358, schematic work stabble.

[6666]

It replased by LM358, schematic work stabble.

Thank you Eddy71

[johnandles]

It replased by LM358, schematic work stabble.

This is an 8 pin device.
The schematic uses a 14 pin.
Regards
John

[Thomas]

Like this

[6666]

Thanks
as above

TAKE NOTE if you use some other op amp than a K157UD2
then disregard the pin numbers and make connections to the correct + and - inputs.

[dfbowers]

I think what you have posted above is about as basic as you can get.

[mikebg]

Like this[ATTACH]22636[/ATTACH]

Yes, like this, but you should remove notation K157УД2 and place the suitable IC, for example like this:

[techo_bob]

Just looking at this schematic

this would make a great pinpointer

Cheers Bob..

[Davor]

My thought exactly

T2 could be replaced with a more humble BJT - MOSFET is an overkill here, and it can be supplied with 9V battery.

[Davor]

VT4 on the original schematic seem to be MJE13007 - the specs fit the bill

[ODM]

Curiously simple design. Has anyone built this one and have protos for show? I'm contemplating this one instead of the microcontroller freq shift detector I currently have in the works as a kids' toy... That one is easy to tune with a single pushbutton though. I'll push schematics and algorithms for it sometime.

[Eddy71]

Many people on the Russian forum make this circuit. It works immediately and without problems. If there are no errors in the assembly.
25mm copper disk detects a distance of 20-25cm.

[brucester]

Just wanted to say thanks again for this. It's exactly what i was looking for.

Pure simplicity. Learned more from this circuit than my entire time on the web :P

Will start the build as soon as my parts arrive

[Thomas]

I have to say thanks to Eddy also, I really like the simple design, my parts arrive Tuesday hopefully.