Magnetic passive elements play a crucial role in various electrical applications and equipment. Magnetic losses account for a significant portion of the total losses. This paper presents a platform for characterizing electrical steel under different operating conditions. The test system comprises a material excitation setup based on linear power amplifiers, voltage and current measurement and conditioning unit, and an algorithm for loss calculation. A two-loop control system ensures accurate tracking of both magnetic flux density waveform and average magnetic field intensity. The proposed approach is validated through simulation results using PLECS software and experimental results. Through experimental measurements, it was possible to estimate the magnetic losses of a toroidal sample, yielding values of 0.510 W/kg for 0.9 T and 1.539 W/kg for 1.5 T, both under excitation at 50 Hz.