Step-Down Transformer - GCSE Physics Definition

A step-down transformer is a device that reduces the voltage of an alternating current (AC) entering it. It has two coils of wire, called the primary and secondary coils, which are wrapped around an iron core. When an alternating current (AC) flows through the primary coil, it creates a magnetic field that induces a current in the secondary coil. In a step-down transformer, the secondary coil has fewer turns of wire than the primary coil, causing the voltage to decrease. This type of transformer is used to make sure that high voltages from transmission cables in the national grid are reduced, so voltages entering homes and businesses is at a safe and usable level.