Can pinpointer detecting thin chain?

[Nupi]

OK, thanks, I've started to mount, wish me luck ......

[Davor]

TLC271 has an unique feature: a bias select. So you MUST connect pin8 to a steady voltage, in this case connecting pin8 (bias select) to a non-inverting input pin3 is OK. Connecting pi8 of most other opamps will result in things unexpected. CA3140 has no such quirks, and I found it cheaper locally.

[Nupi]

@ Davor

Is any problem when I use the TLC271 instead of CA3140? Should I change maybe C9?

[Nupi]

ToddB66 said to me, that he found the data from the pinpointer confused.

***He has absolutely right, I've messedup.***

I often (I mean to frequently) made mistakes.


That's why I post all the data of the PP together.


I hope this time without error.

[Thomas]

Davor, Thanks much for the explanation, It is still very interesting, you do come up with some good Ideas.

[Nupi]

@Davor

OK, I'm going to download it and also thanks you for your schematic, it looks very nice

[Nupi]

@Thomas

Thanks Thomas for the schematic.
Nice avatar you have.

[Davor]

C7 gets charged via R7, from top to bottom, and when it passes ~2.5V U3c and U3d toggle by means of a syncing circuitry. D3 accelerates discharging for the purpose of repetitive use. This circuit is a timer that switches from stabilising stage to the active stage.

Nupi, this schematic is built in ExpressSCH which is a freeware, and often used here.

[Thomas]

Davor, I found this interesting, could you tell more, I think it's for input stability, but not sure.

Nupi, here you go.

[Nupi]

Thanks Davor but I can't open the file!

Eagle light
Error: line 1, column 1: Start tag expected.

[Davor]

Yesterday I transferred a LTspice solution to ExpressSCH. I did not check it for errors yet, and I did not make it in hardware yet, but here it goes anyway.

I think the best hardware solution would be a narrow PCB for placing everything into a tube, so that it can go under water. A pushbutton can be replaced with a reed relay and it can be operated with a magnet from outside. I expect a single 9V cube to last for a season, so - why not hermetising it even with a glue. I could take it for a dive.

[Davor]

A bit crazy is almost always a good thing

[Nupi]

OK, I'm going to work with as soon as I have the parts.
Do not worry that you are so far the only one that really understands.
"....but hardly to anyone else". If so, it is often a very good sign,
and would often say that you brains work in higher spheres than the rest.
I was, according to many people totally crazy, (maybe I am too ) and said that my PP would never work with the CD4024.
silly trolls.

[Davor]

Soon. This is uncharted territory. Let it pickle a bit more - you never know if anything else pops up.
I have this corrected version in Spice and it is completely clear to me, but hardly to anyone else. I'll transfer it to ExpressSCH when I'm done.
For the time being, this is what I got:

[Nupi]

When you think you have the schematic with the new changes?
I wait to build and experiment with everything together.