Can pinpointer detecting thin chain?

[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.

[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?

[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)

[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

[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.

[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.

[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.

[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.

[Waikiki_Sweep]

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

Great job!
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.

Or you can use small 12v batteries for photo cameras:
Ultra 12 V Type G23A is know as 23A, 23GA, A23, E23A, GP-23A, GP23A, K23A, L1028, LR23A, LRV08, LRVO8, MN21, MS21, V23, V23GA, VR22

http://www.ebay.com/itm//281155577756

It is smaller pinpoiinter ever build.

[Thomas]

I took a few things off board, for a small board, I do everything I can SMD.

[Nupi]

MINI

Schematics from the mini-pinpointer nupi.

Who wants to build the pinpointer smaller you can build the mini - pinpointer nupi.
The sensitivity is less than the "Big one" but it is worth to try it yourself.

I have the schematics adapted and given him the name mini - pinpointer nupi

[Nupi]

Nice schematic. I think power consumption is less than 100 mA so you can use smaller size (transistor looking) voltage regulator like 78L05.

Also CD4024 can drive some low load itself so you can use small buzzer with capacitor or LED with resistor to make cheaper simpler version of that pinpointer without second transistor.

You're right. You can use smaller size (transistor looking) voltage regulator like 78L05.


I often use the LP2950 regulation ic with an low input-to-output voltage differential
Low Input-to-Output. Voltage Differential of 50 mV at 100 A and
380 mV at 100 mA. so you can use the 9V battery longer.

Thanks Waikiki_Sweep you're right again, CD4024 can drive some low
load itself so you can use a buzzer. I have experimented with, a time ago,
but only with a LED I had no success.
With only a buzzer worked fine. I do not remember what voltage used for the buzzer.
The sensitivity is less than the "Big one"
But you can try.


I will soon post the schematics of the smaller variant pinpointer. (the mini)

[Nupi]

NUPI thank you, excellent documented!

I drew the PCB of the pinpointer compact design with non-SMD parts.
Plate size is 40x40mm. If you like the design you can use it in your kit for sale.
The upper 3 pads is for coil, middle 2 pads is for supply, lower 2 pads is for motor.

I wonder if you could do some testing with the usual materials, to compare data:
Aluminum foil of chocolate: 3x3mm, 2x2mm and 1x1mm
Copper wire 0.4mm diameter: 3mm, 2mm and 1mm
I do not have a gold chain ...

Nice job Harp.

Thank you but I'm not go make a kit.

I have not yet looked good but Its looks that the transistor BD139 is not good.
See the picture.

It is important that R1 NOT placed on the PCB
With R1 you adjust the sensitivity and the "ground balance".

I have do for you some testing with the Aluminum foil of chocolate: 3x3mm, 2x2mm and 1x1mm
Copper wire 0.4mm diameter: 3mm, 2mm and 1mm

This is the result:
3mm aluminium = 7mm
2mm aluminium = 3mm
1mm aluminium = 0mm

3mm copper wire o,4mm = 2mm
2mm copper wire o,4mm = 1mm
1mm copper wire o,4mm = 0mm

regards

[Thomas]

Forgot a black and white and some silk screen mistakes.
and TR2 is a 2n5551

[Thomas]

I made a few changes SMD with some trough hole. any mistakes?