Harmonic

A sinusoidal component of voltage whose frequency is a multiple of the fundamental frequency. Harmonic oscillations are often caused by modern electronic devices that receive current in "pulse form" rather than in uniform, sinusoidal waves, as was the case with older non-electronic devices. These pulses cause distortion of the waveform of the current, which in turn leads to voltage distortion. Current and voltage harmonics can cause problems such as overheating in wiring, terminals, motors and transformers, and accidental tripping of circuit breakers. Back