another inverter project


Author Message
nickskethisniks
Senior Member

Joined: 17/10/2017
Location: Belgium
Posts: 190
Posted: 01:00pm 21 Jan 2020      

So you don't see it as a problem the way I wound the inductor?

I know the core will saturate @ those current levels. I used an etd59 for more than a year now, considering the size (cross section) that will saturate @ half the current.


You motivated me to do some more research, so I found a site where I could do some calculation.

This morning I looked back at the bobbin and it "looks" more like 22 turns then 25.

So I found this website to calculate saturation of an inductor.

http://pigeonsnest.co.uk/stuff/core-saturation.html

Datasheet of the core is found here:
https://www.ferroxcube.com/upload/media/product/file/Pr_ds/U100_57_25.pdf

It doesn't matter one or 2 core halves for the calculation?

So if I derrive some information:
For a certain airgap with one bobbin I could measure 60uH.

AL= L/n² =60uH/22²= 123.97nH/n²

If I use the tool and use the following data as reference:

AL=123.97nH/n²
Bsat= 0.32T (datasheet)
L = 60µH
Ae = 645mm²

Then I get 75A for the saturation current.

If I do this for my ETD59 core I get about 30.6A for 320mT and 38A for 400mT, if I remember right it was somewhere between 30 and 40A. So these look the right numbers.


I could parallel 2 inductors in series to reach my goal.