felezjoo PI(the best pulse induction metal detector that I made until now)

[useus]

I built a small spider coil to look for mostly gold.
the coil has the following characteristics


27 turns 0.45 copper wire
inner diameter 65mm
outside diameter 120mm approx
4.5 ohm
autodelay 14
good A B C values 296-703-798 (improved by modifying pulse)
I have not yet measured the inductance but it is almost certainly about 400uH
since the coil came to me decently, before removing the turns I ask you.


Is autodelay 14 a good value for gold research or is it necessary to approach the autodelay 20 value as recommended in the various guides?


thanks

[LUPENGR29`]

mohamadreza26204

Please can you upload Sprint-Layout 6 file to print it

[pigeon]

knozy.koom.ma تحسين فلزو - Recherche Google

[pigeon]

this design is not for you it for adam from jordani. in this website knozy.koom.ma تحسين فلزو - Recherche Google

[windaube]

-voltage regulator must have heatsink
-you have to use correct components, looking at your board i don?t see tantalum and ceramic capacitors.
-current should be ok, depend on the coil and pulse width.
-number A is high, maybe because of CA3130
-24v i think is quite high

thanks for the help
I have to replace the yellow capacitor by ceramic capacitor? the pcb seems correct?

to make tests I made 3 coils
Coil1 : 6.5cm 0.235mH 1ohm 0.5mm wire
Coil 2 : 20Cm 0.356mH 1ohm 0.6mm wire
Coil 3 : Spider coil -240-260mm 0.315mH 1.3ohms 06mm wire

I detect a coin of 1 euro at 10-15 cm max,all the coils have the same distance


I tried the CA3031 and the TL081CP, the results are different

Coil 1 :
CA3031 - delays 16, F24000, A587 B825 C832
TL081CP - delays 15, F8000, A175 B392 C399

Coil 2 :
CA3031 - delays 23, F24000, A588 B822 C829
TL081CP - delays 22, F7500, A155 B274 C373

Coil 3 :
CA3031 - delays 18, F24000, A581 B820 C829
TL081CP - delays 14, F7800, A167 B283 C384


with tl081, ID is always 99 and "FE 0".
with the CA303, the numbers change, but seem wrong, the display always shows "FE" and never "NO-FE"
So I think I have a problem,

I tried to replace R6 with a 10K potentiometer, with the CA3031 it is impossible to find less than 400 on the A value.
with the tl082, I get 300 on the value A; and approximately B700 C850

Do you have an idea of the problem ?

[ionut_mtb]

If you check the attachment in the 1st post, you will find a list of components.
Coil need to be spider, aprox 1ohm 300uH - for best result. Your ABC numbers will not be correct (300 700 800) with that IC.

[Emersonpaz]

In felezjoo pi there are three capacitors that give stability to the system, which are of C11 C12 and C6 tantalum I noticed that you did not use.
the 100n capacitors must be ceramic and you used polyester.
finally you should try the LF357BJ, LF357J if possible LF357H metal encapsulation.

[pigeon]

ADAM

this design is from ADAM

[folharin]

tantalum capacitors I used bipolar electrolytic and showed no change in performance!

[folharin]

what I realized that the soil swing has to be done every 10 seconds here in my region

[useus]

minha regi?o ? terra vermelha altamente mineralizada..o que atrapalha o funcionamento do aparato..eu tenho que fazer o balan?o do solo a cada 2 segundos !!!

try
ground 1
integrw 20 or less
sens 12
delay 20 or less
speed 7 or less

[LUPENGR29`]

this design is from ADAM

ferrite? what I can use? any spec?

[useus]

ferrite? what I can use? any spec?

just ferrite? many things are not clear about this design

[pigeon]

just ferrite? many things are not clear about this design

all is clear

[LUPENGR29`]

all is clear

Any ferrite would work? if it is ok I have many