I need help with idx pro silverdog red pcb!!

[Qiaozhi]

Then just use D_Coil_as_Circ_Diam , in a Coil Calculator to get Inductance.

If you're putting the coil diameter into the Coil Calculator, then that's your problem. You should be entering the radius.

[chiuino]

The problem is why with 110inner radius 0.7mm wire for 35turns the coilcalc gave me 0.721mH inductance when other people says .587mH with the same wire and turns and coil diameter!
Thanks Qiaozhi

P.s. Only if i reduce at 31 turns i approach .571mH but this value not equal to .587 where is the truth....

[gaby_sult]

The problem is why with 110inner radius 0.7mm wire for 35turns the coilcalc gave me 0.721mH inductance when other people says .587mH with the same wire and turns and coil diameter!
Thanks Qiaozhi

read this.IDX_Concentric_coil.pdf

[chiuino]

Oky doky

Thx gaby_sult

[Qiaozhi]

The problem is why with 110inner radius 0.7mm wire for 35turns the coilcalc gave me 0.721mH inductance when other people says .587mH with the same wire and turns and coil diameter!
Thanks Qiaozhi

P.s. Only if i reduce at 31 turns i approach .571mH but this value not equal to .587 where is the truth....

For a 270mm diameter DD coil, you have two diameters for each D-shape. To get an approximation of the radius for an equivalent circular coil, the calculation is (270 + (270 / 2)) / 4 = 101.25mm. Not 110mm. With 35 turns of 0.7mm wire, the inductance is calculated as 652uH.

Obviously the inductance calculation is not an exact science, but it does get you close to the correct value. However, to paraphrase Charles Babbage ... "rubbish in, rubbish out".

[chiuino]

THANK YOU very much
You've been really help for me! Thanks again

Andrea.

[Koala]

Hi eduardo and Lamoiz

I have problem Q4 BC517, always getting Hot, with or without sound beep.

Speaker with too low an impedance and a solder bridge were the last two causes of this.

Everything on the board should remain cold.

[chiuino]

While I wait the pcb from silverdog.....i make this one for educational


But i still have to find time to build the coils

Good weekend to everyone!!!

[chiuino]

These are my last progresses on idx pcb
I wait ic's and mpsa13


Cheers

[chiuino]

Hi friends!!!
This is my progress to IDX pro.....homemade pcb
all seems to work but i have some doubt on sensitivity...


The detector is able to view 1euro coin at about 25cm with discrimination
but i have the same distance without discrimination....why?
the coils are properly nulled with oscope and with perfect nulling point when i turn on the detector emits a slight noise only.
I return to forum for news!!!

Bye

[Nandor]

Hi
Your PCB looks very nice, great job! What IC do you use as U3? LM324 or LMC6484 or LF347? I have tried with LM324 and I only got 25cm but with LMC6484 i've got 30+. With LF347 you should get 35 or more outside! not in the house. I have the same distance with or without disc on a euro coin about 33cm with LMC6484.

[chiuino]

Hi Nándor thanks!!!for u3 i've used lf347 but indoor i think the performance is not very good!! I want to test it outdoor but for final making i need a few days!!!!
See you next time for some news

[BKY1337]

I thought the depht from the IDX Pro is 45-60cm with a coin???

[kt315]

I thought the depht from the IDX Pro is 45-60cm with a coin???

yup. but only with a mantra from Holy Al-Qoran on the lips.

[chiuino]

But i think that 25~30cm for one euro are improvable...