BS EN IEC 63093-1:2020 pdf download

5.2 Mating surfaces

These surfaces are generally ground in order to limit the residual air gap between the twocore halves. Consequently，irregularities on these surfaces have to be considered as majorones,and carefully evaluated with regard to their influence on the magnetic properties of thecomplete circuit.

5.3 Centre post

This should be considered as the most important part of the core due to its function ofcarrying the total flux generated by the winding.The centre post of ferrite cores is generallycircular (with or without a hole) or rectangular. if the centre post is circular, it is called centrepole and if the centre post is rectangular, it is called centre leg.

5.4 Outer legs

The main function of the outer legs is to guide the magnetic flux in a closed magnetic circuit.
5.5 Back, bottom surface and back surfaces

The back has the same magnetic function as the outer legs; it can include wire-slots and wire-way areas (for example on RM-cores), the shapes and dimensions of which are dictated bythe winding and isolation requirements.

Besides accommodating clamping，the back surface (ground or not) serves as a referenceplane for grinding the mating surface to achieve is required parallelism，flatness andsmoothness.

5.6 wire-slot area

The wire-slot area is the lateral area of the outer walls, interfacing with the cut-out portion.