Question about coil calculator

[lmrubin]

The coil calculator asks for the wire diameter. I assume this is just the actual metal wire, and not the insulation right?

I think I read that it's better when there's more distance between windings? I assume that means that inductance is partly dependent on the distance between windings? The calculator doesn't ask about how thick the insulation is, or if the wire is single or multi-strand, or what type of metal the wire is.
I'm just trying to understand...do those things matter, or do they not matter enough to take into account? Or is the calculator just meant to give a rough estimate?

I guess I have a lot more reading to do - I'm still confused about the relationship between inductance and capacitance and all the other variables that I probably don't even know about yet! This stuff is definitely not easy, especially without an engineering backround!

[Skippy]

The coil calculator asks for the wire diameter. I assume this is just the actual metal wire, and not the insulation?
Correct. Though if you're using enamelled copper wire, the enamel layer is typically fairly thin, relative to the wire. So you could get away with using the total diameter, if you were unable to determine the actual copper size.

I read that it's better when there's more distance between windings? I assume that means that inductance is partly dependent on the distance between windings?
"Better" ? Better for what ? Windings with a distance between them certainly result in a different coil, with different characteristics. Whether these characteristics are what you're wanting or not affects what you're perceiving as 'better' or 'worse'. The coil inductance does depend in part on the distance between wires. Two adjacent wires interact with each other magnetically - if they are close, this interaction is strong; space them apart, it weakens. More spacing means less total inductance, and other characteristics change too.

The calculator doesn't ask about how thick the insulation is, or if the wire is single or multi-strand
The calculator assumes there is zero thickness insulation, and I'm pretty certain it assumes the wire is square in cross-section, and is packed into a neat square shaped 'bundle' , so clearly it does not perfectly reflect the actual situation of round wire, with insulation, arranged in a vaguely hexagonal way. However, in practice, it produces quite good results for tightly-assembled bundles of regular round ecw (enamelled copper wire).
When winding with multiple strands together, it would be appropriate to calculate an equivalent single-strand diameter, then use that in the Coil Calculator tool. For example if you wound three strands of 0.50 mm ecw together, your equivalent single wire is ( 0.50 x square-root of 3 ) = 0.87 mm diameter.

The calculator doesn't ask what type of metal the wire is.
The assumption is you're using copper wire. If it's silvered or tinned, it makes little difference, as the plating is so thin. Aluminium wire is rarely used in detector coils, so you would be 'pioneering' to try it.

Is the calculator just meant to give a rough estimate?
It gives a decent figure for ecw bundles, as used in a typical VLF detector search-coil. It's more of an estimator for complex situations, like PVC-insulated wire and various alternatives like figure-8 loudspeaker cable, data cable, etc.

I guess I have a lot more reading to do. This stuff is definitely not easy, especially without an engineering background!
I agree, you're definitely jumping in the deep end.

[6666]

The coil calculator asks for the wire diameter. I assume this is just the actual metal wire, and not the insulation right?

I think I read that it's better when there's more distance between windings? I assume that means that inductance is partly dependent on the distance between windings? The calculator doesn't ask about how thick the insulation is, or if the wire is single or multi-strand, or what type of metal the wire is.
I'm just trying to understand...do those things matter, or do they not matter enough to take into account? Or is the calculator just meant to give a rough estimate?

I guess I have a lot more reading to do - I'm still confused about the relationship between inductance and capacitance and all the other variables that I probably don't even know about yet! This stuff is definitely not easy, especially without an engineering backround!

I find the forum calculator to be more accurate if you have thick insulation like pvc then use the outside diameter not the wire size

[waltr]

I find the forum calculator to be more accurate if you have thick insulation like pvc then use the outside diameter not the wire size

Correct.The calculator needs the total diameter including insulation. This allows the calculation to take into account the conductive wire spacing.

[6666]

I also add 1-2 turns before cutting the wire, its best to have too much to begin with and then remove turns.

[Sergey_P]

this is a calculator for calculating the inductance of the coil, not for calculating the coil for MD

[Qiaozhi]

this is a calculator for calculating the inductance of the coil, not for calculating the coil for MD

It is an air-cored calculator suitable for metal detector coils.

[Sergey_P]

the coil (TX) in the MD creates the necessary magnetic field (B) and is sensitive to the environment ( q-factor of the coil, Q). The inductance of the coil (L) does not matter.

[dbanner]

this is a calculator for calculating the inductance of the coil, not for calculating the coil for MD

Yes, I understand what you are inferring.

The parameters of the coil (Q) is an important consideration in metal detector coil. So for TX coil, inductance isn't as important as the efficiency of the tx circuit itself (coil included) and the Q of the coil.

I try to understand this topic, it is not so easy.

The calculator is merely a turns and guage computer for a specific inductance. Not the same thing.

[Sergey_P]

Forum about MD, not about elements of radio engineering

[dbanner]

Most people already know the coil they are aiming to build based on prescription outlined in a project details or cloning a factory coil.
The coil calculator is just a tool which allows them to achieve the prescribed coil as per requirement of the project.

Yet few people know how these specs are arrived at.
Seems you know much on the subject. Please share more.

[Sergey_P]

The MD coil is selected from the energy preferences (B)
B=((m*m0/(2*pi*r))*I ~ I
I=i*w current through the coil
The coil (i) depends on the power source (E), the coil q (Q), the switching frequency of the coil (F), the connection in the electrical circuit, the size of the coils that determine the voltage (U) on the coil.
After calculating the required number of turns in the coil, if necessary, calculate the capacitance of the capacitor circuit (C)
Example for MD Quasar:
https://my-files.su/ed0p7m
https://my-files.su/oz21vb

[dbanner]

The MD coil is selected from the energy preferences (B)
B=((m*m0/(2*pi*r))*I ~ I
I=i*w current through the coil
The coil (i) depends on the power source (E), the coil q (Q), the switching frequency of the coil (F), the connection in the electrical circuit, the size of the coils that determine the voltage (U) on the coil.
After calculating the required number of turns in the coil, if necessary, calculate the capacitance of the capacitor circuit (C)
Example for MD Quasar:
https://my-files.su/ed0p7m
https://my-files.su/oz21vb

Thank you very much!

[Op04]

The MD coil is selected from the energy preferences (B)
B=((m*m0/(2*pi*r))*I ~ I
I=i*w current through the coil
The coil (i) depends on the power source (E), the coil q (Q), the switching frequency of the coil (F), the connection in the electrical circuit, the size of the coils that determine the voltage (U) on the coil.
After calculating the required number of turns in the coil, if necessary, calculate the capacitance of the capacitor circuit (C)
Example for MD Quasar:
https://my-files.su/ed0p7m
https://my-files.su/oz21vb

Sir, The link is expired, would you please share it again. Thank you very much! Regards

[Sergey_P]

please share it again. s

https://transfiles.ru/inf2p