electronics

A Bell Labs film in which Dr. J.N. Shive uses a mechanical wave machine to demonstrate reflection, standing waves, resonance and impedance matching. He includes some equations but relies mostly on real-world examples a layperson can follow.

Rick Hartley gives a roughly two-hour live training on proper grounding in PCB design. He explains how energy actually flows in the space between conductors, and how that governs noise, EMI, return paths and signal reflections.