Wiring an iron powdered core to be used as an inductor

Thread Starter


Joined Dec 30, 2020
-have calculated the desired inductance to be 291.7uH ,
-peak inductor current to be 1.5A,
- chose the T106-26 as my iron powdered core ((Al value/100turns)=900)
-calculated the number of turns (N=100*sqrt(deired inductance/Al value)=56
-wired the torrodial core with AWG 22 wire size with a maximum current rating of 1.8A

but my inductance is far beyond this value .....did i do the correct thing or missing something


Joined Aug 21, 2008
The frequency doesn't appear to be an issue.
Carlton Dranko wrote:

"- chose the T106-26 as my iron powdered core ((Al value/100turns)=900)"
Just a note AL is usually given in terms of nanohenries per thousand turns squared or my shortcut. It helps if we all speak the same engineering language. Had to go to the micrometals website to confirm your calculation, which I did, so it looks like

The inductance you are getting is way out of the 10% AL tolerance. If you have not already done so you might want to measure the physical dimensions to check whether you have the particular core (T106-26) that you think you have.


Joined Aug 7, 2020
1.06" diameter - the clue is in the part number!
I prefer Al in nH/turn^2, and that's how Micrometals specifies it. The good thing is that with three different preferences, we've all got to the same answer!
Micrometals warns us about the number of fakes out there, but you'd only get 14uH if it were made of compressed sawdust, and it sounds like it's too heavy for that.