Magnetic core
The magnetic circuit that channels the flux between primary and secondary.
Definition
The magnetic core is the magnetic circuit of a transformer: it channels and guides the flux created by the primary coil towards the secondary coil. Without it, the coupling between the two windings would be negligible and the efficiency would collapse.
It is made of laminated silicon-steel sheets (or a grain-oriented strip for toroidal cores), assembled in thin layers insulated from one another. This lamination is essential: it breaks up eddy currents into elementary circuits, drastically reducing iron losses by induction.
The geometry of the core (E-I, U-I, toroidal, shell-type) influences the compactness, the noise level and the no-load losses of the transformer. Toroidal cores radiate very little and are ideal for environments sensitive to magnetic interference.
The ABL tip
ABL Transfo selects its magnetic steels according to the target working flux density. For low-loss applications, we use premium NO (non-oriented grain) sheets or GO (grain-oriented) strips for toroidal cores. The core cross-section is calculated to the millimetre for each project.
