Fourier Series: Any Wave Is Just Sine Waves Added Up

Any repeating signal, however jagged, is a sum of smooth sine waves. A square wave is a fundamental plus odd harmonics; add them one at a time and watch the corners appear. That is the Fourier series.

The video builds a square wave and a sawtooth from sines, shows the spectrum, and explains why this is the tool behind audio, vibration analysis and power electronics.

In this video

• Any periodic signal as a sum of sines
• Building a square wave harmonic by harmonic
• What the spectrum shows
• Where it's used: audio, vibration, power