In a word, a transformer is a static electrical device that transfers electrical energy between two or more circuits through electromagnetic induction. It primarily consists of two key components: a high voltage winding and a low voltage winding, both of which are wrapped around a common core, typically made of a high-permeability material like silicon steel.

The high voltage winding, as the name suggests, is designed to handle high voltage inputs. This winding is usually made of copper or aluminum conductors, with copper being the more common choice due to its superior electrical conductivity. The high voltage winding is subjected to high electrical pressure, which necessitates the use of thicker and well-insulated wire to prevent electrical breakdown and ensure safe operation. The number of turns in the high voltage winding is typically higher than that in the low voltage winding, as it is directly proportional to the voltage ratio of the transformer.

On the other hand, the low voltage winding is wound with a relatively lower number of turns and is designed to deliver electrical energy at a lower voltage. This winding also uses copper or aluminum conductors, with the choice depending on factors such as cost, efficiency, and the specific application requirements. The low voltage winding is subjected to lower electrical pressure, allowing for the use of thinner wire with less stringent insulation requirements compared to the high voltage winding.

The core of the transformer plays a crucial role in facilitating the transfer of electrical energy between the high voltage and low voltage windings. It is usually made of laminated silicon steel sheets, which are stacked together to minimize eddy current losses and enhance the magnetic coupling between the windings. The core provides a low-reluctance path for the magnetic flux generated by the high voltage winding, which in turn induces a voltage in the low voltage winding through electromagnetic induction.

In summary, a transformer's high voltage winding and low voltage winding, along with the core, work together to step up or step down voltages, depending on the application. The high voltage winding is subjected to high pressure and is designed to handle large amounts of electrical energy, while the low voltage winding delivers this energy at a lower voltage, making it suitable for various end-use applications. The transformer's ability to efficiently transfer electrical energy without direct electrical contact makes it an essential component in power transmission and distribution systems, as well as in numerous industrial, commercial, and residential applications.