In what capacity are capacitors used in power supplies?

Capacitors are primarily used in power supplies to store electrical charge. This capability allows them to smooth out voltage levels by providing energy quickly in response to load changes. When a power supply experiences a transient load or a sudden change in current demand, the capacitor can release its stored energy to maintain a constant voltage level, thus preventing sags or spikes. This function is particularly crucial in applications where steady DC output is needed, as fluctuations can impact the performance of sensitive electronic devices.

While increasing voltage, eliminating current fluctuations, and regulating frequency are functions associated with various other components like inductors and transformers, the fundamental role of capacitors in this context centers around their charge storage capacity, which is essential for stabilizing the power supply output. This ensures that the circuitry operates smoothly and reliably.