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A novel round cable electromagnetic interference (EMI) suppressor comprising a bundle of Mn–Zn ferrite tubes was realized using different principles of suppressing, such as direct suppressing, inverting/suppressing, transform/inverting suppressing, and transform/short circuited secondary suppressing. Different primary to secondary configurations were realized for each suppressing principle and characterized in the EMI frequency region. The results obtained for different bundle configurations were compared with known commercial round cable ferrite suppressors and the initial bundle configuration made of a half turn wire through the central ferrite tube of the bundle. The results obtained for different principles and configurations were correlated in order to optimize the electromagnetic coupling between primary and secondary circuits. The values such as maximums of impedance Zm, frequency of maximum impedance Fm and suppressing range \Deltaf around Fm calculated on 0.707 Zm were defined as the main parameters for each configuration. Certain correlations were noticed between impedance Zm and frequency Fm changes. Finally, the realized configurations were considered as devices suitable for EMI suppressing applications. [ABSTRACT FROM PUBLISHER]

A novel Mn-Zn ferrite round cable electromagnetic interference (EMI) suppressor with deep grooves and a secondary short circuit was constructed, realized and measured. Three steps were passed in novel suppressor development: from developing a suitable magnetic material, to constructing a suppressor device, to forming a new class of possible applications. Soft ferrite feedstock was formed from fine commercial Mn-Zn powder and a Solvent system binder based mainly on wax. Cylinder-shape cores with grooves were injected by powder injection molding (PIM) technology, chemically and thermally debinded and sintered at optimal conditions (1280^\circ\C/2\ \h). The samples were aimed to serve as cores for EMI suppressors on cables. Their impedance versus frequency was measured using the core length as a parameter. After that, copper wire was placed into the grooves on the outside surface of cores to form a secondary coil and different configurations were considered. The contribution of the short circuit coil inserted into the grooves to EMI suppression was measured and analyzed also. Maximal impedance values can be achieved with a secondary short circuited winding which passes through every groove. It was also shown that ferrite cores of the same length could be used for different frequency ranges by changing the configuration of secondary short circuited windings. [ABSTRACT FROM AUTHOR]