“S”- tone discriminate metal detector.

[peih]

why can not remove the ferrite rod adjusts when GND

[ivconic]

"...when a huge iron comes front to the coil at the end of its detection range
it detect it like a good metal with high freq tone..!!!.."

I experienced the same behavior.
I think it is mostly due imperfect coil quality build. Those are resonant, therefore must be done perfect!
Never really tried to solve that problem. My pcb with components is still somewhere in workshop, waiting for better times!

BTW; you pcb is very good (on skim look), i just don't like cap footprints (spacing). I do prefer 5mm spacing. However it is much better solved pcb than my pcb! Bravo!

[Naeem]

schematic & PCB

[Naeem]

good result but bad disc

hello all experts.
I built this S detector by sascho.overall its performance is good.i made one DD coil and one OO coil for this setup.
with DD coil (without resonant caps) it can detect a 2.5cm coin at 32-33cm with a little change in threshold.
DD coils data ara same that ivconic post here but different in turns (85turn).with default OO coils (without resonant cap parallel again)
it detect same coin 27-28cm in air.but there is a problem here....... when a huge iron comes front to the coil at the end of its detection range
it detect it like a good metal with high freq tone..!!! lets solve this problem because this detector is very nice with good detection range.
and i can post here the small pcb (10*10cm) that i made. another question: wich coil is better in real soil because air test isnt matter.
thanks.

[Mohar]

До Нико
Нямам време за коментари,а и никой не ми плаща за това.Служебно съм много зает.Този форум е на английски, а с английския съм много зле.А и не виждам смисъл да се правя на велик с отдавна известни неща.
С уважение: Сашо

Здравей колега Сашо !!! Имам едно питане към тб . Може ли E-mail ?

[rauno]

works good, very stable.

[kuraja]

Thanks! I will find them (no TIP 122)!

[Götz von Berlichingen]

TIP127 replacement :
BD266B, BD650, BD702 (different package)
its Si PNP, Darlington, 100V, 5A, 65W

If a BC516 works here too, the TIP127 may be overkill

Arbeitet gut.
Instead TIP127 place bc516. Work.

[Götz von Berlichingen]

My old Transistor Book says, TIP122 can be replaced by
BD267B, BD649, BD701 (different package)
Its a Si NPN Darlington, 100V,5A 65W
I hope this helps

EDIT : are you sure you want a TIP122, not a TIP127 ?

can you tell me the replacement for TIP 122, and LM2930-8???

Its not the same but he can use 7808 there!So its replacement.

About TIP122 I am not so shore but there is also replacement.Look at datasheet kuraja!You will find similar.

LM2930-8 is NOT 7808
LM2930 Low-dropout regulator
7808 -U IN-UOUT=2V MINIMAL

LM2930-8 is 7808

tip122 is tip122 see datasheet

[kuraja]

can you tell me the replacement for TIP 122, and LM2930-8???

До Нико
Нямам време за коментари,а и никой не ми плаща за това.Служебно съм много зает.Този форум е на английски, а с английския съм много зле.А и не виждам смисъл да се правя на велик с отдавна известни неща.
С уважение: Сашо