The E55/28/25-3C95 is a Transformer Core made with material grade of 3C95. The shape of E core is derived from the classical iron sheet lamination core. For the original E range in fact the dimensions of the existing lamination range were taken so that already commercially available coil formers and mounting hardware could be used. The former EF range has been optimized for the use of ferrite as a core material. Cross sections were rearranged resulting in a homogeneous magnetic flux density in the core and more space for the windings. Main use is as power transformer or chokes in SMPS. E core has a simple shape and can therefore be produced more economically than more complicated cores. A drawback is the rectangular cross-section of the centre pole which makes it more difficult to wind, especially with heavy wires. Also the structure of the core is rather open resulting in stray flux sometimes causing interference problems.
