Is a transformer primarily used with AC or DC voltage?

A transformer is primarily used with alternating current (AC) voltage. This is because a transformer operates on the principle of electromagnetic induction, which requires a changing magnetic field to induce voltage in another coil of wire. AC voltage naturally changes direction and magnitude over time, creating the necessary changing magnetic field for the transformer to function effectively.

When a transformer is connected to an AC source, it can efficiently step up or step down the voltage as needed, which is essential for power distribution systems. Conversely, transformers are not designed to work with direct current (DC) because DC provides a constant voltage without the oscillations needed to produce the changing magnetic field. As a result, when DC is applied to a transformer, there is no induction occurring, and the transformer will not function as intended. Thus, the use of a transformer is specifically tailored to AC applications.