transformatorid

Transformatorid, or transformers, are electrical devices that transfer alternating-current energy between circuits through electromagnetic induction. In an ideal transformer, a changing current in a primary winding creates a varying magnetic flux in a shared core, which induces a voltage in a secondary winding. The voltages are related by the turns ratio V1/V2 = N1/N2, and the currents by I1/I2 = N2/N1, so power is conserved (neglecting losses).

Transformatorid consist of windings (usually copper or aluminum) mounted on a laminated magnetic core to reduce energy losses. They are available in various forms: step-up transformers that raise voltage, step-down transformers that lower it, isolation transformers that provide electrical separation, and autotransformers that share windings to be more compact for small voltage changes. Three-phase transformers use three-phase windings for power transmission.

Key performance characteristics include efficiency and losses: core losses (hysteresis and eddy currents) and copper losses in windings, as well as stray losses. Voltage regulation is the change in output voltage under load. Impedance determines short-circuit current and fault behavior. Insulation, cooling, and protective enclosures are important for safety.

Transformatorid are central to electrical power systems, enabling efficient high-voltage transmission, distribution to homes and industries, and various specialized roles such as instrument transformers for metering and protection, or audio and signal transformers in electronics.

History: the principle was described by Faraday in the 1830s; practical transformers were developed in the late 19th century and became widespread with the adoption of alternating current power.