Down the Harmonic Rabbit Hole Part 2: Synchronous Detection

In my prior post about harmonics I delved into the sine wave. In this post I want to show a practical use of this understanding.

Down the Harmonic Rabbit Hole - Part 1: Sine Waves and Triangles

I want to go down a rabbit hole in the mathematics of harmonics in signals, but first I need to do some ground-work, so here is some explanation of sine waves.