This document provides an overview of transformers, including:
1. Transformers work by transferring electrical energy between two coils through magnetic induction, allowing voltage levels to be increased or decreased without loss of power.
2. They consist of two coils wound around an iron core, with the primary coil receiving alternating current from a power source and the secondary coil outputting a different voltage determined by the ratio of coil windings.
3. Transformers function based on Faraday's law of induction - a changing magnetic field in the primary coil induces voltage in the secondary coil. The ratio of voltages between coils equals the ratio of coil windings.