The starter relay simply switches off this de-magnetisation winding for a short moment and the inverter generates the mentioned voltage spikes of a flyback converter. These appear on the secondary ...

In another video, he goes over the wiring of a fluorescent starter to create a flickering effect with an incandescent light bulb. A fluorescent starter works because the current heats up a gas ...

Older fluorescent fixtures used a "starter" (modern versions are selfstarting) to fire up the gas in the tubes. When the starter doesn't work, the light just flickers, never truly fully lit.