How to Calculate and wind Toroid Core inductors

[@josepeixoto3384]

bad start for me Al ,4 , 50 what are those?

[@jboy4real]

Please how did you come about the value of the inductor to be 100uH before design

[@BalticLab]

That is shown in my videos on Wilkinson Power Splitters

[@huss03]

I'm looking at manufacturer's data for a specific toroid and the AL figure given appears to be within the range of 89 - 210. How does one possibility design around that kind of variance?

[@BalticLab]

If no dependent variable is given for the range, I'd use the geometric mean for design, so sqrt(89×210) = 136.71 nH

[@huss03]

@@BalticLab Thank you very much. For reference, the part number is Proterial FT-3KM 4627H. Thanks again!

[@dalenassar9152]

You really need to use the INNER circumference of the toriod to calculate the # of turns that will fit, since this is the limiting factor for the max. number of turns that can fit...you will have gaps between wire turns on the outer surface when the inner circumference is tightly filled. Thanks for the great video...I am especially interested on the Al factor. Can you maybe do a video mainly explaining Al and using it??

[@dalenassar9152]

I am still a bit confused about this calculation. If AL is given in micro henires (uH), and AL=4uH, Then only ONE turn would give an inductancd L=4uH...which is 4000nH...already 10 times higher than what you need (400nH). THANKS for making me think. BTW: I have found that just touching the leads of an inductance meter through (or inside) the toriod, gives a direct reading of AL.

[@BalticLab]

The AL value is given by Amidon in µH per 1000 windings. The inductance L is thus calculated by: L = (AL × N^2)/1000 where N is the number of windings.

[@isaaclomas1304]

where do you find the value of AL?

[@BalticLab]

In the Datasheet.

[@ndidikenneth5135]

I have seen some numerous examples of inductor winding with superfluous maths can't inductor winding be explained without these hassles? I still don't get it

[@BalticLab]

No, because then it would be a 30 second video at max as anyone should be capable of wrapping some wire around some core material without guidance. To know how much wire you put on there, that is kind of the part that needs figuring out.

[@JohnTarbox]

Excellent tutorial!

[@mohammadalfauomey3443]

I can't see well what you wrote . You must magnify the picture . Thanks

[@dalenassar9152]

Have you actually measured the inductance of your toriod-wound 10 turn coil??...maybe not. I have tested this using L=AL*(N^2) with several different coils, and this formula worked every time. 400nH is quite small for winding on a toriod (whenever I need < 10uH, I have always used air-core). The first thing that comes to mind when I see a required 400nH (0.4uH), is 'air core'. If you measure the L of your coil, I think you will get about 400uH...not 400nH...that's 1000 times higher. THANKS, --daLe

[@BalticLab]

Your statement is still incorrect. Please note that different manufacturers give their AL values in different "units". L=AL*N2, L=(AL*N^2)/1000, L=(AL*N^2)/1000^2 and L=(AL*N^2)/100^2 are all acceptable equations for toroid inductance depending on the manufacturer's specifications. While I didn't specifically measure the inductor, I did use it in a practical, reactance dependent circuit. And the performance was spot on (kzbin.info/www/bejne/aXqkh31qnLuopKc). Additionally, online calculators would confirm my math for the Amidon cores: toroids.info/T50-6.php