In this video, the author will talk about how and why dangerously high voltages can be generated from the collapse of the stored magnetic energy in the coil when they are switched off, and how the diode can protect the low power electronics from being damaged by these high voltages. Some voltage and current measurements are made on an actual circuit to see the real- world effects.

A copy of the notes in the video can be found here: click here

Courtesy: w2aew