Transformer

A transformer is a stationary device -- with no moving or rotating parts at all -- used to transform electrical power from one AC circuit to another, working entirely on the principle of mutual induction between two coils, without changing the supply's frequency in the process. The applied alternating voltage can be either INCREASED (a step-up transformer) or DECREASED (a step-down transformer), always with a corresponding decrease or increase in current, so that the product (power) is conserved. This section covers a transformer's construction and working, its efficiency and the several distinct energy-loss mechanisms that keep it below 100% efficient, and …