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Technical Notes

Harmonic Distortion
A perfect sinusoidal shaped signal, be it acoustic, voltage or current signal is per definition a "clean", pure, one-frequency signal. When another frequency is overlaying the original signal, the signal becomes distorted and no longer perfectly sinusoidal. Especially when the overlaying or interfering signal has a constant mathematical relationship to the original sinusoidal signal, for instance twice the frequency, or half the wavelength of the original signal.

Harmonics distortion is the interfering frequencies with a constant mathematical relationship to the original signal. Hence the term "Harmonics".When dealing with harmonic distortion on the mains supply, the interfering frequencies will then derive from that basic frequency, 50Hz or 60Hz.
The problems with harmonics distortion arise when electronic devices generate harmonics on the mains, and thereby "pollute" the source for other electronic devices. In sensitive environments, such as hospitals, airports, banks and other buildings or institutions with sensitive electronic equipment, it is crucial that the harmonic distortion is kept at a minimum. Several authorities also demands compliance to IEC or other Standard Organization regulations.


 For further information please contact your local Danfoss Company