My science is a little shaky on just how much power can be generated from a magnet. I’m guessing no much. The video suggests it is enough to provide like to ride by. I’d want to see for myself. I wonder if that flimsy mount doesn’t tend to slide around thus disturbing the magnetic field and dimming or turning off the light altogether? Corrie
Rotating a conductor next to a magnet induces a current within the wheel. This current, in turn, creates its own magnetic field, which can be used to generate current to drive a light. Because the light is affixed to the brake caliper, when you tap the brakes you get a bonus feature: brighter light for an automatic brake light. Cool, huh?