Set-up and measurements on a Mn-Zn ferrite ring core under sinusoidal excitation and dc bias conditions

This paper introduces a set-up for core loss measurements of Mn-Zn ferrite ring cores under sinusoidal excitation and dc bias conditions. The set-up is based on a tailor-made cost-efficient power amplifier. Measurements are performed on a non-gapped core at room temperature and 100 kHz operating frequency, where both pure ac excitations and such with various levels of dc biasing are considered. Data regarding the resultant B-H loops, volumetric power loss figures and effective amplitude permeability are presented. The results show that with dc bias the effective amplitude permeability of a non-gapped core is not a symmetrical quantity. Considerations regarding the utilization of the amplifier are discussed.