Transformeraren

Transformeraren, commonly understood in Swedish-language contexts to refer to the electrical device known as a transformer, is a passive device that transfers energy between circuits through magnetic coupling. It usually consists of one or more windings—primary and secondary—mounted on a shared magnetic core. The device operates on the principle of electromagnetic induction discovered by Michael Faraday; when alternating current flows in the primary winding, a changing magnetic flux induces a voltage in the secondary winding. The voltage ratio is approximately equal to the turns ratio between windings, while the current ratio is the inverse, conserving power (ignoring losses). Transformers do not transmit direct current; they require alternating current and a suitable operating frequency.

Design variants include power transformers for high voltages, distribution transformers for lower voltages, and instrument transformers for measuring currents and voltages. Special types include isolation transformers, autotransformers, and step-up or step-down transformers, each serving different safety or performance roles. Core material, lamination, conductor resistance, and cooling method affect efficiency, core losses (hysteresis and eddy currents) and copper losses. In modern practice, transformers are highly efficient, with losses minimized through materials, cooling, and precise manufacturing.

Historically, the concept emerged from early electromagnetic research in the 19th century. The first practical transformer was built in the 1880s–1886 by William Stanley, and rapid development followed, enabling the adoption of alternating current power distribution worldwide.

In Swedish-language contexts, transformeraren is used to refer to the transformer as a component in electrical systems, and is a staple in power engineering, electronics, and utility infrastructure.