A first approach :
µ0*N^^2*S/L.
Parasistic elements are uncomputable.


Peter Percival a écrit le 20/08/2019 à 16:07 :
> Somewhere there must be a formula for the inductance of a hand-wound 
> coil.
>
> Air core, one layer of wire (of given swg) close-wound, diameter of 
> former (cardboard, probably inside of toilet paper roll), length of 
> coil,... (what else?), therefore inductance equals ...

On 8/20/2019 9:07 AM, Peter Percival wrote:
> Somewhere there must be a formula for the inductance of a hand-wound coil.
> 
> Air core, one layer of wire (of given swg) close-wound, diameter of 
> former (cardboard, probably inside of toilet paper roll), length of 
> coil,... (what else?), therefore inductance equals ...

If your getting into crystal radio,
  You might find this interesting,
> http://theradioboard.com/rb/viewforum.php?f=2
and this overwhelming,
> http://makearadio.com/crystal/index.php

                    Mikek

amdx wrote:
> On 8/20/2019 9:07 AM, Peter Percival wrote:
>> Somewhere there must be a formula for the inductance of a hand-wound 
>> coil.
>>
>> Air core, one layer of wire (of given swg) close-wound, diameter of 
>> former (cardboard, probably inside of toilet paper roll), length of 
>> coil,... (what else?), therefore inductance equals ...
> 
>   Yep a dozen.
>   I have spreadsheeet labeled the Nagaoka Formula that is supposed to be 
> very accurate. You can search for it, But I think these use his formula,
> 
>> http://www.mogami.com/e/cad/coil-01.html
> 
> 
> If you want a deep understanding, with Nagaoka.
>> http://mathscinotes.com/wp-content/uploads/2014/04/lundin_Proc_IEEE_1985.pdf 
>>
> 
> Otherwise, dig into these. Or just the first one.
> 
>> http://crystalradio.net/professorcoyle/professorcoylecyl.shtml
> 
>> http://electronbunker.ca/eb/InductanceCalc.html
> 
> 
>> https://www.translatorscafe.com/unit-converter/ja/calculator/coil-inductance/?D=2&Du=cm&l=1&lu=cm&N=10 
>>
> 
> use the second on this page.
> 
>> http://www.circuits.dk/calculator_single_layer_aircore.htm
> 
>> http://www.66pacific.com/calculators/coil-inductance-calculator.aspx
> 
>> https://coil32.net/online-calculators/one-layer-coil-calculator.html
> 
>> https://hamwaves.com/inductance/en/index.html#input
> 
>> https://www.qsl.net/in3otd/indcalc.html
> 
>> https://knowpapa.com/inductance/
> 
>   That's enough so you will never know who is correct :-)
> I ecpect
> 
> The ones I have used is Professor Coyle, and I had a downloaded version, 
> so haven't tried the online version and electronbunker.
> 
>                               Mikek
> 
Ooh, there's lots!  Thank you.

On 8/20/2019 9:07 AM, Peter Percival wrote:
> Somewhere there must be a formula for the inductance of a hand-wound coil.
> 
> Air core, one layer of wire (of given swg) close-wound, diameter of 
> former (cardboard, probably inside of toilet paper roll), length of 
> coil,... (what else?), therefore inductance equals ...

  Yep a dozen.
  I have spreadsheeet labeled the Nagaoka Formula that is supposed to be 
very accurate. You can search for it, But I think these use his formula,

> http://www.mogami.com/e/cad/coil-01.html


If you want a deep understanding, with Nagaoka.
> http://mathscinotes.com/wp-content/uploads/2014/04/lundin_Proc_IEEE_1985.pdf

Otherwise, dig into these. Or just the first one.

> http://crystalradio.net/professorcoyle/professorcoylecyl.shtml

> http://electronbunker.ca/eb/InductanceCalc.html


> https://www.translatorscafe.com/unit-converter/ja/calculator/coil-inductance/?D=2&Du=cm&l=1&lu=cm&N=10

use the second on this page.

> http://www.circuits.dk/calculator_single_layer_aircore.htm

> http://www.66pacific.com/calculators/coil-inductance-calculator.aspx

> https://coil32.net/online-calculators/one-layer-coil-calculator.html

> https://hamwaves.com/inductance/en/index.html#input

> https://www.qsl.net/in3otd/indcalc.html

> https://knowpapa.com/inductance/

  That's enough so you will never know who is correct :-)
I ecpect

The ones I have used is Professor Coyle, and I had a downloaded version, 
so haven't tried the online version and electronbunker.

                              Mikek

On Tue, 20 Aug 2019 15:07:07 +0100, Peter Percival
<peterxpercival@hotmail.com> wrote:

>Somewhere there must be a formula for the inductance of a hand-wound coil.
>
>Air core, one layer of wire (of given swg) close-wound, diameter of 
>former (cardboard, probably inside of toilet paper roll), length of 
>coil,... (what else?), therefore inductance equals ...

of course there are.  Your google is broken?

BTW single layer solenoid-wound coils usually hit the calculate values
spot-on, it doesn't start to get hairy until you add layers.  There's
a formula that takes into consideration the diameter/length ratio too,
but for simple single layer coils try the "Amateur Radio Handbook."

Somewhere there must be a formula for the inductance of a hand-wound coil.

Air core, one layer of wire (of given swg) close-wound, diameter of 
former (cardboard, probably inside of toilet paper roll), length of 
coil,... (what else?), therefore inductance equals ...