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

[amer]

try 2n7002

[bandito]

Where to buy the software without limitation

[bernte_one]

i think you can get it from Ivica Conic in serbia (hope he is well so far, miss his postings)

[cvele]

OK, here I go again with debug numbers,
a)300
b)700
c)800
first and second I can achieve without problem by simply using proper parts, speedy coil (350uH-spider) and proper pulse width: 300,700 but problem is c)780/790!!! Whatever try score is the same = 780/790, so: what that number is for, please tell me if someone know that, and how to get it? I made few of them, but newer c)=800, all of them works stable but i am curious about it. Regard

[jladre]

OK, here I go again with debug numbers,
a)300
b)700
c)800
first and second I can achieve without problem by simply using proper parts, speedy coil (350uH-spider) and proper pulse width: 300,700 but problem is c)780/790!!! Whatever try score is the same = 780/790, so: what that number is for, please tell me if someone know that, and how to get it? I made few of them, but newer c)=800, all of them works stable but i am curious about it. Regard

Do not expect to get that number perfectly because they are only the average. If you get 780 to 820 then thats is perfect.

[cvele]

So this is it. Thank You very, very much jladre!
regard

[steaua581]

Anyone knows what commercial coil might work with felezjoo? Can it be Minelab coils?
Maybe someone has some info (measurements) on the market coils which might be suitable. I guess i could pay 100$ 150$ for a professional coil other then searching blindfolded. And after all you wont be able to make a high performance coil with the home hobby measuring equipment

[jladre]

Anyone knows what commercial coil might work with felezjoo? Can it be Minelab coils?
Maybe someone has some info (measurements) on the market coils which might be suitable. I guess i could pay 100$ 150$ for a professional coil other then searching blindfolded. And after all you wont be able to make a high performance coil with the home hobby measuring equipment

I think coil from surfmaster pi will work.. the old surfmaster nit the dual field.. but making your own is the best.

[Altair]

OK, here I go again with debug numbers,
a)300
b)700
c)800
first and second I can achieve without problem by simply using proper parts, speedy coil (350uH-spider) and proper pulse width: 300,700 but problem is c)780/790!!! Whatever try score is the same = 780/790, so: what that number is for, please tell me if someone know that, and how to get it? I made few of them, but newer c)=800, all of them works stable but i am curious about it. Regard

Hi cvele,
could you post some photos of your coil, please?

[cvele]

Hi Altair,
coil is in shell and fill with uretane foam, but i decide to make new one 25cm (also spider 250uH), and will make some pics wen I finished it.Just few days maybe.Here is jpg of template
that I usually use.
regard

[smit22]

hi cvele.

250uh.Is a low capacity. The auto delay will be less than 20 chars standar. Almost as much as 12 or 13 or 15 more sensitivity and not good for stability. Add a few turns of wire in order to get closer to 20 delay. 21 will be good. For bigger delay reel more than 20 will be effective .25 or 28 will be good with 400 uh but if the delay is buckets over 20 the iron rejection does not work and if the delay is over 30 the sensitivity falls If you have a longer delay remove some coil wires the delay will be tomeber. The letter c indicates that your device does not need a oscilloscope if it is always more than 100 with the digit of letter b less than 20 or More than 20 no problemme like 80 or 120 and if it is trops indicates that there is problem mosfet or coil or ic357 has the waveform

[basellafe]

[cvele]

Hi Smit22,
thank You for advice, actually I made mistake, NOT "250uH" but 350uH, and that is start point for playing around with coil til get proper debug numbers. Yes, auto delay is about 15, but have stability and nice iron rejection. I will try with 400uH and report.
regard

[cvele]

I am completely confused now. With 400uH coil (I mean inductance, not capacity) debug numbers are completely wrong, 350-360uH are ok, here what I notice about coil and stuff around: INDUCTANCE AND SORT OF COIL AFFECT THE LETTER a) AND b), KIND OF WIRE FROM COIL TO PCB AFFECT LETTER b) - and that is it. Next, My English is terrible and I do not understand meaning of : "The auto delay will be less than 20 chars standar" . In My vocabulary (its old but works) can not find translation, so please, would You explain me in easy English what does that mean?
Regard

[smit22]

The standard number of automatic delays is 20. More of this number gets more stability. No problem if the delay is less than 20. As 16 or 15 but 20 delays are better .400 uh is for large coils like 60cm or 1m. And mr hamid advised for large coil The goal is to get a more automatic delay of more than 20 or 25 or 28 or 30 and effective for stability with large coils. But for small induction coils from 300 to 350uh is good.car with the numbers of The automatic delay coil will change. Increases with more turns and falls with fewer turns