transzformer

Transzformer, commonly called transformer in English, is a passive electrical device that transfers electrical energy between circuits through electromagnetic induction. It changes voltage and current levels while keeping the frequency fixed, enabling efficient energy transfer across varying loads and distances.

Principle: When an alternating voltage is applied to the primary winding, a time-varying magnetic flux links the windings, inducing a voltage in the secondary proportional to the turns ratio, V2 = (N2/N1) V1 for an ideal transformer. Real transformers have losses and impedance, but the turns ratio determines the voltage transformation; current is inversely related. They require alternating current and operate with laminated ferromagnetic cores to guide flux and reduce losses.

Construction: typically two or more windings on a magnetic core made of laminated steel or ferrite, depending on frequency. Windings are copper or aluminum insulated; cooling ensures safety.

Types and uses: power and distribution transformers step up or step down voltages in electric grids; autotransformers share winding for smaller costs; isolation transformers provide galvanic isolation; instrument transformers such as current and potential transformers scale down large currents or voltages for measurement; audio and isolation transformers used in electronics.

Efficiency and limitations: modern transformers achieve high efficiency (often 98-99%), but losses include core (hysteresis, eddy current) and copper losses; they only operate with AC and within rated frequency.

History: the concept arose with Faraday, with the first practical high-efficiency transformer built by Ottó Bláthy, Miksa Déri and Károly Zipernowsky in 1885 at Ganz Works in Hungary, enabling modern AC power distribution.