A linear regulator steps down voltage by resisting the excess, burning it away as heat. It is smooth, continuous, and inherently wasteful.
A buck converter steps down voltage through violence. It refuses to burn the excess; instead, it chops the input into a brutal, high-frequency square wave—turning the voltage entirely on, then entirely off, thousands of times a second.
This jagged violence is fed into an inductor. The inductor acts as a heavy flywheel for the current, resisting the sudden changes. It absorbs the brutal chops and averages them out, releasing the energy as a smooth, continuous, lower-voltage flow.
Efficiency is achieved not through gentle reduction, but through high-frequency violence smoothed by magnetic inertia. The chop becomes the flow.
