What is the primary function of a transformer?

The primary function of a transformer is to change the voltage level of an alternating current (AC) signal. This process occurs through electromagnetic induction, allowing the transformer to either step up (increase) or step down (decrease) voltage levels while maintaining the power in the system (minus any losses due to efficiency).

Transformers operate by using two coils of wire, known as windings, that are placed around a core. When an alternating current flows through the primary winding, it creates a magnetic field that induces a voltage in the secondary winding. The ratio of turns in the primary and secondary coils determines the change in voltage; for instance, if the secondary winding has more turns than the primary, the voltage is increased, and if it has fewer turns, the voltage is decreased.

This voltage transformation capability is vital in power distribution systems, where high voltages are used for transmission over long distances to minimize energy loss and lower voltages for safe usage in homes and businesses.