transformer

A transformer is a device that transfers electrical energy between two or more circuits through electromagnetic induction. It typically consists of primary and secondary windings wound around a magnetic core. When alternating current flows in the primary winding, a changing magnetic flux induces a voltage in the secondary winding. Transformers do not require moving parts and provide voltage or impedance conversion while isolating circuits. They are rated by apparent power (kVA or MVA) and come in various forms, including step-up (increasing voltage), step-down (decreasing voltage), and autotransformers that share windings. Efficiency is high in modern designs, but core losses (hysteresis and eddy currents) and copper losses in windings reduce performance. Safety concerns include insulation, cooling, fire hazards in oil-filled units, and proper grounding.

In artificial intelligence and natural language processing, a Transformer is a neural network architecture introduced in 2017 that relies on attention mechanisms rather than recurrence. Its core components are self-attention layers, multi-head attention, position-wise feed-forward networks, and positional encodings to capture order in data. Transformers enable parallel processing of input sequences and effectively model long-range dependencies. They form the basis of many state-of-the-art models, such as BERT for understanding and GPT for generation, often in encoder-only, decoder-only, or encoder-decoder configurations. Variants optimize for efficiency or tasks like translation, summarization, or dialogue.

In popular culture, Transform ers (sic) refer to a media franchise originating with Hasbro and Takara, featuring sentient robotic beings from the planet Cybertron that can transform into vehicles or other forms. The franchise spans toys, animated series, comics, and films, with iconic characters such as Optimus Prime and Megatron. The term Transformer is sometimes used in reference to these characters or to the broader concept of transformable robots.