BS EN IEC 63093-1:2020 pdf download

BS EN IEC 63093-1:2020 pdf download.Ferrite cores-Guidelines on dimensions and the limits of surface irregularities Part 1: General specification.
5.2 Mating surfaces
These surfaces are generally ground in order to limit the residual air gap between the two core halves, Consequently, irregularities on these surfaces have to be considered as major ones, and carefully evaluated with regard to their influence on the magnetic properties of the complete circuit,
5.3 Centre post
This should be considered as the most important part of the core due to Its function of carrying the total flux generated by the winding. The centre post of ferrite cores is generally circular (with or without a hole) Or rectangular. If the centre post Is circular, It is called centre pole 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 surfac. 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 by the winding and isolation requirements.
Besides accommodating clamping, the back surface (ground or not) serves as a reference plane for grinding the mating surface to achieve Its required parallelism, flatness and smoothness.
The wire-slot area is the lateral area of the outer walls, interfacing with the cut-out portion.
8 Limits of surface Irregularities
8.1 General
In each particular specification relevant to a standardized core series, generic rules for the calculation of limits should be defined for every kind of Irregularity and for all core parts and surfaces.
For guidance on the limits of irregularities, refer 10 the sectional specifications of the IEC 63093 series, where limits according to core size are given in suitable tables, along with identification of irregularity types on figures and drawings.
8.2 Chips and ragged edges
The simplest way of performing inspection on these two types of irre9ularities is to compare a chip to a reference area limit and a ragged edge to a reference length.
The limits of chips are generally defined as a percentage of the related surface of the core. The apparent area of a chip is considered to be tile area of that chip.
The ragged edge length is generally limited to a percentage of the common perimeter of the
respective two surfaces.
8.3 Cracks
The limits of cracks are generally defined as a percentage of the specified core section thickness.
The length of a crack Is considered to be the actual length visible on the surface without magnification.
8.4 Flash
Generally, no limit Is defined but the critical places where flash Is not allowed should be listed.