In an ideal situation, all loads and sources have a pure sine current waveform. Unfortunately, the true waveforms of most devices are very different. Nonlinear loads, such as the diode input bridge of a 6-pulse driver, are causing voltage distortion in the power supply. The distortion assessment, usually evaluated by total harmonic distortion (THD), ranges from the 2nd to the 40th harmonic frequencies. In a 50Hz network, this is the region between 100Hz and 2kHz. The effects of voltage distortion are diverse, with the most typical being overheating in transformers and PFC applications (capacitor banks). The impact of harmonic distortion is underestimated, which significantly reduces the expected lifespan of electrical and mechanical equipment. The Der Revcon harmonic filter (RHF) avoids harmonic distortion from nonlinear loads and sources. This filter is not tuned to a specific frequency, but works like a bandwidth filter, reducing all frequencies to the 50th harmonic. The RHF filter reduces the total harmonic distortion (THDi) of the current to a level significantly below 5%. This is necessary for achieving an increasing number of universal standards, such as IEEE 519-2014.