The one that [Made in Poland] chose to sacrifice was particularly nasty and greasy, but after popping off the pulley, the treasure within was revealed: the large, ring-shaped clutch electromagnet.

A coil with an iron core is called an electromagnet. The iron core increases the coil’s magnetic field strength. A simple electromagnet is made by coiling wire around an iron nail. An iron core ...

This is mechanical energy in action. The mechanical energy is caused by the attractive force of the electromagnet. Now imagine a circle of electromagnets that you could turn on and off one after ...