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

[gurdal]

Hello to everyone
LF357J and LF357H have no problem.
works fine

[hooby life]

Thanks spalio I mean this lf357h
And I need specific big coil

[sbalio1]

Yes, you can use lf357h. You can also use lf157n.Better than others

For small and medium sized coils, it is best to use wires with a diameter of 0.5 or 0.6 and a maximum of 0.7. The more the diameter of the wire affects the numbers of the separation channel and the outo delay and the greater the inductance, the smaller the numbers and the longer the delay.

[hooby life]

Hello gays
Can use lf357h metal

[6666]

i found this website helpful: https://www.simplemetaldetector.com/...imination-fix/
you can adjust the first numer A to get the one you need. i use ca3130 and number A is 500. i can adjust it like in the link above to 300.
Does the dumping resistor affect the numbers/functionality of the detector? i did not tried my scope on it... i use dumping resistor like in the schematic (390ohm)

Thanks for the link that site has some good info

[ionut_mtb]

i found this website helpful: https://www.simplemetaldetector.com/...imination-fix/
you can adjust the first numer A to get the one you need. i use ca3130 and number A is 500. i can adjust it like in the link above to 300.
Does the dumping resistor affect the numbers/functionality of the detector? i did not tried my scope on it... i use dumping resistor like in the schematic (390ohm)

[useus]

""the diameter of the coil (big coil close 400uH, small coil close 350uH)" ...???????? NO.the impedance value depends;
the diameter of the wire, the number of turns, the spacing of the wires, the total diameter, the damping resistor's .... ...
my coil diameter 30cm...
thank you

yes but felezjoo works well 400uh with large coils, with small coils you have to lower to 350uh or less

if your coil and cable are good then it may be the damping resistor that is not correct,

[lamoiz]

""the diameter of the coil (big coil close 400uH, small coil close 350uH)" ...???????? NO.the impedance value depends;
the diameter of the wire, the number of turns, the spacing of the wires, the total diameter, the damping resistor's .... ...
my coil diameter 30cm...
thank you

[lamoiz]

yes, i use low impedance cable ... like instrument cable. yes too .380mh ..... 380uh ...
THEN what are the good parameters for the coil ??????
nevertheless, a coil at 11 is a fast coil, no?

[useus]

my coil is a double spider coil with a damp on the central coil (the small) the wire is 0.8mm,
the total capacitance is 100pf with the cable. it is not yet shielded (always on the work plan ..)
380mh and 0.94ohm.the delay at power up is 11 ..
thank you.

it depends on your type of cable, the type of wire, the diameter of the coil (big coil close 400uH, small coil close 350uH) etc ... 380mh I think you mean 380uH. I do not use shielding even on the cable even if it is present in it.
I use for example enamelled copper SWG22 which is slightly smaller, about 0.71 and high quality microphone cable.
from the values your lf357 would seem good, it is the coil and the cable that do not go well.

probably with a correct coil and a good cable you should get closer to the correct values

[lamoiz]

my coil is a double spider coil with a damp on the central coil (the small) the wire is 0.8mm,
the total capacitance is 100pf with the cable. it is not yet shielded (always on the work plan ..)
380mh and 0.94ohm.the delay at power up is 11 ..
thank you.

[lamoiz]

I read the link.
what are the values A B C? on my felez, there are 550 for A 650 for B and 700 for C .... I read that it needed 300 700 800 ...
thank you.

[useus]

Hello,
in the picture, you indicate the voltage of your battery.
it's not my original question.
when powering on the detector, it indicates a delay. It depends on the coil you have. This depends on the internal parameters of the cable and the care of the damping resistor.
You who have reels that disc perfectly, what do you like delay ??
Thank you.

delay 19 on power up. I have not yet increased or decreased the value manually to do tests

[lamoiz]

Hello,
in the picture, you indicate the voltage of your battery.
it's not my original question.
when powering on the detector, it indicates a delay. It depends on the coil you have. This depends on the internal parameters of the cable and the care of the damping resistor.
You who have reels that disc perfectly, what do you like delay ??
Thank you.

[6666]

https://felezjoo-pi.blogspot.com/?view=classic&m=1

Thanks for that link