Coil Calculator 2

[gabryx]

The coil calculator that is stiked in forum is wrong, i get

3.891 mH

While with the calculator I made and also with Coil64 I get 1.647176965 mH.

With my program, which also considers Brooks and spiral coil, you can also see the results with a Colpitts tank and with RLC tank.
You can download it at this address:
https://mega.nz/file/21BDgA6R#JuiCry...w1-Imi8IMmhVZQ

[Qiaozhi]

The coil calculator that is stiked in forum is wrong, i get

3.891 mH

[ATTACH]57785[/ATTACH]
While with the calculator I made and also with Coil64 I get 1.647176965 mH.
[ATTACH]57786[/ATTACH]
With my program, which also considers Brooks and spiral coil, you can also see the results with a Colpitts tank and with RLC tank.
You can download it at this address:
https://mega.nz/file/21BDgA6R#JuiCry...w1-Imi8IMmhVZQ

Try putting in the correct values. Then you'll find that the inductance is 1.647mH.
As it says in BOLD type:
One common mistake is to enter the diameter of the coil, instead of the radius, into the first field of the dialog box.

Your program also gives the correct answer, but it's huge and only runs with Windoze .... 59.2MB in zipped format, and 151.2MB when decompressed!
Whereas, the Geotech calculator is only a miniscule 49.1kB and runs in any internet browser that supports Javascript, which makes it platform independent.

Just saying.

[gabryx]

Try putting in the correct values. Then you'll find that the inductance is 1.647mH.
As it says in BOLD type:
One common mistake is to enter the diameter of the coil, instead of the radius, into the first field of the dialog box.

Your program also gives the correct answer, but it's huge and only runs with Windoze .... 59.2MB in zipped format, and 151.2MB when decompressed!
Whereas, the Geotech calculator is only a miniscule 49.1kB and runs in any internet browser that supports Javascript, which makes it platform independent.

Just saying.

OOOppsss...Sorry for the mistake, but I'm used to working with the diameter of objects.
Unfortunately, some CADs also use the radius to create a cylinder and force the user to perform a very boring division that can cause mistakes, for example dividing 6 in diameter to obtain a radius of 3 is simple, but if we have to divide a 17922.1955 the what becomes more complex.Of course, the Java program does not occupy anything compared to a compiled one (where I wanted to include the libraries if one does not have the correct Framework installed) ... but now the space in the hard disks is not a problem and in any case in a second the program starts without opening any browser.
As you could see I also put some routines to see the result by applying capacitors and / or resistors and see the resonant frequency, in addition to the calculations for voltage divider, OP gain, and a calculation that starts from the weight in grams or Ohms resistance of the copper wire to know the length of the wire (depending on the selected AWG) and then calculate the inductance.
If you find any calculation errors in my program, please report them, for now it has helped me to understand which capacitor to use to have the desired resonant frequency, how many volts / ampere pass in the tank circuit at the moment of resonance and to see how much it should be set. the frequency in Arduino.

Another thing, since you are all very experienced in the subject: I did some real tests with the Colpitt and I saw that the spiral coil "feels" much more than a traditional one, but I see that it is not normally used in metal detectors.
In fact, the magnetic field generated by a normal coil develops mainly inside the circle, while in the case of the spiral it is more flattened.
It is more difficult to build the spiral (apart from those printed in PCB but which have a small copper layer compared to a normal wire and if you want to get a lot of Henry then the Ohms go up too much), but I found a method using a double-sided adhesive strong to create the spiral and then pour over the epoxy to block everything.
Then I have many other questions ... but for now I'll stop here.Hi again and thanks for any replies

[Qiaozhi]

The Tesoro Sand Shark uses a printed spiral coil (see attachment).

Alfonso (ahermida) has been experimenting with PCB spiral coils, and has sent me some examples. The 7" coil seems to work well, and I have a 10" coil that needs testing (not done yet due to other jobs getting in the way).

[gabryx]

The Tesoro Sand Shark uses a printed spiral coil (see attachment).

Alfonso (ahermida) has been experimenting with PCB spiral coils, and has sent me some examples. The 7" coil seems to work well, and I have a 10" coil that needs testing (not done yet due to other jobs getting in the way).

And are the test results good?
And how can aluminum shielding be achieved?
I am attaching here an image of the first construction test I did.
What you see in white is the double-sided tape, but when I do the final one, I saw that it is better to cover the entire surface with the double-sided tape.
Also in this test I hadn't pulled the copper wire well (which comes from a washing machine motor) so there are gaps between the coils.
The wooden cross helps in the creation of the spiral.The magnetic field that develops with the spiral is halfway between the edge and the center, so it is better if the spiral starts from the center, even if the first turns are really short.