Can pinpointer detecting thin chain?

[Nupi]

I took a few things off board, for a small board, I do everything I can SMD.
[ATTACH]29029[/ATTACH]

Hi Thomas, very nice work.

NUPI Maybe Final.png

I just hope it works well in smd.
This circuit is simple but is sensitive to the type of components you use.
It can happen if you use another type of transistor TR2 can do less well (or better ).
It took me many hours to try different parts But as I've said it's a prototype,
so maybe it can be improved.

I've never tried the Circuit itself in SMD. I think it's a good technique, but I can not.
I've tried it several times but My hands are shaking too much.
Maybe it's because of too much tomato sauce in my head.
So I'm glad that others will try.

Can you explain us the advantages of the two front to front diodes?

I'm fascinates if anyone has built the circuit.

regards.

[Nupi]

Note: Note: Note: Note: Note: Note: Note!!!


-- The coil should be no further affirms than 15 centimeters away from the circuit.


-- The signal from IC-1 pin 11 to the capacitor C5 ("Big" pinpointer) may also be taken
from pin 12, depending on the type of buzzer that you use. Let's try what sound you like best.
This also goes for the ("mimi" pointer) but than directly from pin 11 or from PIN 12
to the buzzer.

[Thomas]

Can you explain us the advantages of the two front to front diodes?

When power is shut off to the regulator the output voltage should fall faster than the input. In case it doesn't, D3 is to protect the regulator from possible reverse voltages. D2 is for blowing the fuse if the battery is reversed.

[Thomas]

It will fit 20mm plastic pipe. So you can put a coil with ferrite core in the same pipe.
May be it is possible to add some voltage converter IC to power schematic from one or two AA batteries to let everything to fits that 20mm pipe.
Or may be it will work from 3V at all.

18650 LI-ION batterys are 17.46mm two end to end would work, may have to use a LDO reg. but a 20mm tube maybe a hair to small for the board because of the 220uF cap, we'll see.

[Waikiki_Sweep]

18650 LI-ION batterys are 17.46mm two end to end would work, may have to use a LDO reg. but a 20mm tube maybe a hair to small for the board because of the 220uF cap, we'll see.

18650 Li-Ion is a great solution.

Also you can find smaller Li-Ion batteries

14650-1100mah

14430-650mah
14450-750mah

You can drill a hole in PCB for 220uF cap to let it fit pipe

[bernte_one]

look for the cr123a 3,7V plus step up converter to 5V together smaller than 9v block
use this already for microcontroller projects (teemo pulse oszillator, malysh fm2)

[Harp]

Hi Nupi,
"...I have not yet looked good but Its looks that the transistor BD139 is not good."
BD139 data is from library, as SOT-32 package with ECB configuration (front view).
Where did you get the information for BD139?

[Nupi]

Hi Nupi,
"...I have not yet looked good but Its looks that the transistor BD139 is not good."
BD139 data is from library, as SOT-32 package with ECB configuration (front view).
Where did you get the information for BD139?

Not again,

Harp sorry I was wrong, When I drawing pinpointer nupi 2014.jpg
I swap the character C and B on.
I have so often this circuit constructed in many ways and now I draw BD139 wrong.


Now I must correct pinpointer NUPI 2014.jpg D.....S.......


I'm getting too old for these adventures.

[Nupi]

Here are all the schematics, drawings and pictures of the Pinpointer Nupi 2014
and the Mini Pinpointer Nupi 2014 final.
regards

[greylourie]

Very nice presentation, Nupi. Thanks.

[Davor]

I think I'll give the 4024 portion of a detector a go in spice. It produces that distinctive varying repetition beeps, and seem quite an useful feature.
BTW, maybe a somewhat harder linking of a 4024 detector (pin 5) with the oscillator would be beneficial as it might turn the whole shebang into a super regeneration regime (very sensitive), and also make tuning less critical.

[Nupi]

Very nice presentation, Nupi. Thanks.

You're welcome.

[Nupi]

I think I'll give the 4024 portion of a detector a go in spice. It produces that distinctive varying repetition beeps, and seem quite an useful feature.
BTW, maybe a somewhat harder linking of a 4024 detector (pin 5) with the oscillator would be beneficial as it might turn the whole shebang into a super regeneration regime (very sensitive), and also make tuning less critical.

Have you the possibility to try it?
It would be nice to involve you In this project.

[Nupi]

Water resistant coil

[Davor]

Have you the possibility to try it?
It would be nice to involve you In this project.

Of course I can try it. There are a few caveats though, all related to the CMOS inputs being modelled a bit off, and this particular implementation dances about the switching thresholds. I can use a pair of inverters that are modelled with MOSFETs to mimic the input conditions properly.
I need a pinpointer, and this project seem just right. Yeah, I could contribute a little. I'm not in my full DIY mode right now though.
BTW, did you consider air coil for this one? It would require far more turns of preferably thinner wire, but in the end may result in something far more repeatable. I have a stash of small square plastic boxes, and such box could accommodate an air coil inside, so that the whole design remains small, compact and intrinsic. Otherwise I'd fit it into a tube of some sort and use a ferrite.
I'm also curious - how did you come up with the 4024 detector design? It is very Zen-like and I like it that way.