Transformer

Voltage step-up / step-down · 1885

Two coils sharing a magnetic core — current in the primary winding forges a flux that induces a voltage in the secondary, scaled by the ratio of turns. Transformers are the reason long-distance AC transmission won the War of the Currents: ten thousand volts on the line, then 230 V at the wall. Without them, the modern grid would be impossible.

Key specifications