sähkömuuntajassa

A sähkömuuntaja, or electrical transformer in English, is a passive electrical device that transfers electrical energy from one electrical circuit to another through electromagnetic induction. It is a key component in alternating current (AC) electrical systems. Transformers are most commonly used to increase or decrease AC voltages. They are also used for electrical isolation between circuits, and to allow for the transfer of power between circuits without a direct electrical connection.

The fundamental principle of operation for a transformer relies on Faraday's law of induction. It consists of two or more coils of wire, known as windings, which are electrically insulated from each other but are often wound on a common magnetic core. When an alternating current flows through one coil, it creates a changing magnetic flux in the core. This changing magnetic flux, in turn, induces an alternating voltage in the other coil(s). The ratio of the number of turns in the primary winding (connected to the input power source) to the number of turns in the secondary winding (connected to the load) determines the voltage transformation ratio.

Transformers are essential for efficient power distribution. They allow electricity to be generated at a relatively low voltage, stepped up to very high voltages for long-distance transmission (reducing energy loss), and then stepped down to safer and more usable voltages for consumers. They are found in a wide range of applications, from large power substations to small power adapters for electronic devices. The efficiency of transformers is generally very high, often exceeding 95%.