Magnetic core uniformity

[Mech133]

I am building a C-core similar to the one shown below. there are coils on both down "legs" of the core, and run in complementing polarity. Size constraints prevent me from using uniform cross-sectional area for the vertical and horizontal sections of the core. The horizontal x-section is only 25% the area of the vertical legs. How much of an impact will this have over a core with uniform dimensions in regards to flux generation at the poles? Would I be better off reducing the size of the coils but increasing the thickness of the horizontal section? Is FEA the best way to make this determination?

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[MJR2]

FEA and a bit more information is one way to analyse this. The horizontal section only needs to be large enough to carry the flux that gets there. However one might guess that being only 25 percent of the core would not be enough. If this makes your circuit out of balance you would be wasting much of the ampturns your coils generate.

Mike

 

[TStaples]

Mech133,

It's not possible to be certain from the information that you have supplied. However, MJR2 is correct, if you are attempting to drive the verticle "legs" anywhere close to saturation, and they are the same material as the horizontal portion of the frame, then the reluctance of the horizontal section will be very high soaking up a bunch of the input power.

This does not require FEA to solve. A simple sum of the reluctances math model can be generated via Roter's method, and can be used to optimize the design for steady state. This is easily accomplished via a spreadsheet.

-Tony Staples

http://www.tscombustion.com