What is the purpose of a capacitor in an AC circuit?

In an alternating current (AC) circuit, the primary purpose of a capacitor is to store electrical energy. Capacitors are designed to accumulate and release electrical energy in response to voltage changes. When connected to an AC circuit, they periodically charge and discharge as the current alternates. This ability to store energy allows capacitors to smooth out fluctuations in voltage and current, which can lead to improved overall circuit performance.

Their function in AC circuits is crucial for applications such as power factor correction, where capacitors can help in stabilizing voltage levels and improving efficiency. They also play a role in filtering applications, helping eliminate unwanted noise and smoothing out the output of power supplies.

While capacitors might influence aspects of current flow, they do not inherently increase current or minimize resistance. They also do not convert AC to DC; this specific function is performed by rectifiers. Understanding the role of a capacitor in energy storage and its contribution to AC circuit behavior is vital for HVAC technicians working with electrical systems.