Micrometals PFC torroid inductor calculation

[cupoftea]

Hi,
Just done Torroid (SH134060-2) with 34 turns which gives L0 = 51uH
And At 5.6Amps L = 43uH
However, their inductor calculator says 34 turns gives L0 = 117uH and L = 100uH at 5.6 Amps.

I used the permeability coefficient given on page 32 of their application guide.

Can you confirm? I hope their coefficiencts arent wrong elsewhere too?

SH134060-2

https://datasheets.micrometals.com/SH-134060-2-DataSheet.pdf

Micrometals application guide

https://s3.amazonaws.com/micrometals-production/filer_public/2f/ed/2fedd6eb-44d0-4834-a442-8222486f0b77/micrometals_alloy-en-2021.pdf

 

[FvM]

Al value according to catalog is 102 nH, thus 118 uH nominal inductance for 34 turns. If you measure different value, it's probably other core.

 

[Akanimo]

Hi,

Please show your calculation.

 

[cupoftea]

Thanks, yes i forgot to update the permeability value in the template i'd made out

 

[Akanimo]

Could you present it in pdf, PNG or jpg? I'd be more comfortable with any of those.

 

[Akanimo]

With the AL value, the inductance is very quickly and accurately calculated as FvM as already stated above in post #2.

 

[cupoftea]

Thanks yes, thats only the AL value at zero current.

 

[FvM]

Thanks yes, thats only the AL value at zero current.

Obviously. L0 value should be sufficient to determine which inductance range is correct. How did you arrive at 51 uH? Measurement or calculation?

 

[Akanimo]

Thanks yes, thats only the AL value at zero current.

Yes, definitely. A plot is provided in the datasheet for AL value Vs Ampere-turns. You could read the AL value for your Ampere-turns from there. The method of calculating inductance from the AL value is the same.