Recommended · for some experience
Back EMF High Voltage Spikes on the Oscilloscope - Part 1
Why people recommend it
A scope demonstration of the voltage spike an inductor or relay coil produces when switched off, used to explain why flyback diodes matter.
Watch for: Spikes can reach hundreds of volts; mind your scope's input rating
In their words
From videos on Youtube: [video] and other sources I found out the back EMF spikes usually reach very high voltages even above 400V.
Daniel Vela Jarquín on electronics.stackexchange.com, Nov 2020. CC BY-SA.
In this video you can see that the voltage spike reaches 400 volts in 20 microseconds.
jDo on raspberrypi.stackexchange.com, Mar 2016. CC BY-SA.
