In Common mode choke core how is AL value and impedance related?

Thread Starter


Joined Feb 19, 2020
I have AL value and the dimensions of the core (oval) but I don't have permeability. I want to know the relationship between AL, L0 and Z. How are they related.


Joined Apr 4, 2016
If I remember correctly, AL value = nH per single turn. From this, you can calculate the number of turns required for any value of inductance. Can't remember the formula - will have to check. I'm sure Google (or another search engine) will point you to the answer.
Losses, saturation, ect. depend on other factors.


Joined Aug 21, 2008
That's the easy way to quickly check AL. A more former definition is AL = (L in nanohenries)/(turns squared), which is the same as L over 1 in the case of 1 turn.

Thinking back a ways, the number of turns used in the test is often stated.