Air gap for inductor core

Thread Starter

Manjesh Gowda

Joined Oct 19, 2020
88
Hey guys,

I am designing an inductor for high current where i need Air gap of 6mm in order to avoid saturation.. But the thing is I am not able to find the air the ferrite material which has airgap of 6mm(one side).. So I thought of keeping a plastic of 2mm on both the legs which also make 2mm gap on the center...which makes effective air gap of 6mm (That's what i believe).
The AL value for individual gaps are given in the datasheet but that value is for middle gapped...
My concern is if i keep gap on both the legs like i mentioned, do i get the AL value mentioned in the datasheet for the airgap?
How does it make a difference by adding gap on legs?
I believe that by adding 2mm on both the side gives effective air gap of 6mm..is thst right?
Please let me know...Thank you
 

Thread Starter

Manjesh Gowda

Joined Oct 19, 2020
88
You can text by making the inductor and measuring the inductance.
I think you need 3mm plastic.
Could you brief me y do i need 3mm plastic.. Here I am going to use 2 E cores..I was thinking having 2mm airgap on both the legs makes the airgap of 2mm in middle aswell.. so it will be of 6mm airgap in total.. Please let me know if i am wrong
ferrite-ee-cores-500x500.jpg
 

Thread Starter

Manjesh Gowda

Joined Oct 19, 2020
88
Hey Ronsimpson
Thank you for the clear answer.. I would like to know if i get thee same effect if i do it in another way like having 3mm gaps on each legs...will it be same as having 6mm in the center leg.. how does it effect AL? or do you think i should test it to know the effects.. Please let me know.. Thanks
 

BobaMosfet

Joined Jul 1, 2009
2,113
Hey guys,

I am designing an inductor for high current where i need Air gap of 6mm in order to avoid saturation.. But the thing is I am not able to find the air the ferrite material which has airgap of 6mm(one side).. So I thought of keeping a plastic of 2mm on both the legs which also make 2mm gap on the center...which makes effective air gap of 6mm (That's what i believe).
The AL value for individual gaps are given in the datasheet but that value is for middle gapped...
My concern is if i keep gap on both the legs like i mentioned, do i get the AL value mentioned in the datasheet for the airgap?
How does it make a difference by adding gap on legs?
I believe that by adding 2mm on both the side gives effective air gap of 6mm..is thst right?
Please let me know...Thank you
My personal favorite:

Inductance Calculations
Author: Frederick W. Grover
ISBN-10: 048647440-2
 
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