Its primary function is to store electrical energy and release it when needed. Capacitors are widely used in electronic devices, power systems, and communication networks. In this article, we will explore the purpose of a capacitor in a circuit and how it contributes to the overall functionality of electrical systems.
The stored energy is released as current flows back out of the capacitor. Capacitors block direct current (DC) while allowing alternating current (AC) to pass – at least for a short time while the capacitor charges and discharges. This property makes capacitors highly useful in filtering applications for power supplies and audio equipment.
When a voltage is applied across the plates, an electric field is created, causing electrons to accumulate on one plate while the other plate develops a positive charge. This process allows the capacitor to store electrical energy in the form of an electrostatic field.
When a sudden voltage surge occurs, a capacitor can absorb the excess energy, preventing it from reaching sensitive components and causing harm. This protective function is often utilized in power supply circuits, where capacitors are placed across the power rails to suppress voltage spikes and transients.
When a capacitor is connected to a power source, electrons accumulate at one of the conductors (the negative plate), while electrons are removed from the other conductor (the positive plate). This creates a potential difference (voltage) across the plates and establishes an electric field in the dielectric material between them.
Potential Difference Maintained: The capacitor maintains a potential difference across its plates equal to the voltage of the power source. This potential difference is accessible when the capacitor is connected to another circuit element.