What does a step-up transformer do?

A step-up transformer is designed to increase the voltage while simultaneously decreasing the current in an AC electrical circuit. This is based on the principle of electromagnetic induction, where the transformer has more turns of wire in the secondary coil than in the primary coil. As a result of this configuration, the transformer steps up the voltage from the primary side to the secondary side.

The fundamental operation of a transformer is governed by the relationship between voltage and the number of turns in the coils, which is described by the formula ( V_s/V_p = N_s/N_p ), where ( V ) represents voltage and ( N ) represents the number of turns. In a step-up transformer, the ratio indicates that there are more turns on the secondary coil, thus increasing the voltage.

In practical applications, increasing the voltage is essential for efficient power transmission over long distances, reducing the effects of resistive losses in the conductors. When voltage is increased, current is inversely affected per the principles of power conservation, thereby making transmission more efficient as lower currents result in lower heat losses.