Definition of Capacitor

A capacitor is an electronic component that stores and releases electrical energy in a circuit. It consists of two conductive plates separated by a dielectric (insulating material), which allows it to accumulate an electric charge when a voltage is applied across it. Capacitors are commonly used in electronic circuits for a variety of purposes, such as smoothing voltage fluctuations, filtering signals, and storing energy temporarily.


The phonetics of the keyword “Capacitor” are: kəˈpæsɪtər

Key Takeaways

  1. Capacitor is a cross-platform runtime that allows you to build web apps while accessing native device features using a single codebase.
  2. It acts as a bridge between web apps and native platforms, supporting iOS, Android, and PWA, making development easier and efficient.
  3. Capacitor provides a wide range of native APIs and the ability to write custom native plugins, enabling more seamless integration with desired device features and functionalities.

Importance of Capacitor

The technology term “capacitor” is important because it plays a crucial role in various electronic circuits and devices, functioning primarily as a passive two-terminal component that stores and releases electrical energy.

Capacitors provide a wide range of applications, such as filtering, energy storage, coupling, and decoupling, which contribute to the optimal performance of electronic systems.

They are vital in maintaining stable voltage levels, enabling energy-efficient power supply, signal processing, and power conditioning.

Furthermore, capacitors are essential in alternating current (AC) and direct current (DC) circuits, facilitating noise reduction and protecting sensitive components from voltage spikes.

Their versatile characteristics and functions make capacitors an indispensable element of modern electronics and technology.


A capacitor is a fundamental electrical component that serves a vital purpose in various electronic devices by storing and releasing electrical energy in the form of an electric charge. This essential function is an integral part of numerous electronic circuits, ranging from simple electronic filters to intricate oscillating circuits in devices such as phones, televisions, and computers.

The unique ability of capacitors to quickly store and discharge energy makes them ideal for use in applications where rapid voltage changes need to be smoothed out or where a short burst of power is required. One of the key roles of a capacitor is in signal and power filtering, where it helps to maintain the stability of electrical signals and power supplies in electronic devices.

For instance, in power supply circuits, capacitors can store energy during low voltage periods and release it during high voltage periods, thereby ensuring a stable voltage output. Furthermore, capacitors are utilized in timing circuits, such as in sensors and clocks, to regulate the frequency of electronic signals or voltage pulses.

Additionally, capacitors are incredibly versatile – depending upon their construction and design, they can be tailored to meet specific requirements in numerous applications, including energy storage and frequency tuning in radio frequency systems. In summary, capacitors are a crucial component in the realm of electronics, bolstering the reliability and efficiency of devices we rely on every day.

Examples of Capacitor

Power Supply Smoothing: Capacitors are widely used in electronic devices’ power supplies to maintain a steady voltage output. These capacitors store energy when the voltage is higher and release it when the voltage is lower, effectively smoothing out voltage fluctuations and ensuring a constant power supply. Examples include computers, televisions, and mobile phones, which all utilize capacitors to stabilize their power supplies.

Energy Storage in Electric Vehicles: The regenerative braking systems in electric vehicles (EVs) often use capacitors to store energy generated during braking. This energy is then released to power the vehicle when it accelerates, improving overall efficiency and reducing the load on the battery. Hybrid and electric vehicles, such as the Toyota Prius and Tesla Model S, utilize capacitors for this purpose.

Camera Flash Units: Capacitors play a crucial role in camera flash units – both in professional cameras and smartphone cameras. When a photographer clicks on the shutter button, the capacitor charges quickly and stores energy for a brief duration. Upon triggering the flash, the capacitor releases the stored energy as a burst of light, providing the necessary illumination for the photograph. This is employed in devices like DSLRs, point-and-shoot cameras, and smartphone cameras with a built-in flash function.

Capacitor FAQ

What is a capacitor?

A capacitor is a passive electronic component that stores electrical energy in the form of an electric field. It consists of two conductive plates separated by an insulating material called a dielectric. The stored energy can be released later in the circuit when needed.

What are the different types of capacitors?

There are several types of capacitors, including ceramic capacitors, electrolytic capacitors, tantalum capacitors, and film capacitors. Each type has its own advantages and disadvantages, as well as specific applications in different circuits.

How do capacitors work in a circuit?

When voltage is applied across a capacitor, an electric field forms between its plates, causing the charges to accumulate on each plate. The amount of accumulated charge is proportional to the applied voltage. When the voltage is removed, the capacitor discharges, releasing the stored energy back into the circuit. Capacitors can be used in various applications such as filtering, energy storage, and coupling/decoupling signals.

What is capacitance and how is it measured?

Capacitance is the measure of a capacitor’s ability to store electrical energy. It is expressed in farads (F). The higher the capacitance, the more energy a capacitor can store. Capacitance is typically measured using a multimeter or an instrument called a capacitance meter. The relationship between charge (Q), capacitance (C), and voltage (V) can be represented by the formula Q = C x V.

How to choose the right capacitor for a specific application?

Choosing the right capacitor for an application requires considering several factors such as the required capacitance value, voltage rating, temperature range, and capacitor type. It is essential to select a capacitor with a voltage rating higher than the maximum voltage applied in the circuit to avoid component failure. Additionally, it is vital to consider the application-specific requirements, such as size, tolerance, and temperature coefficient when choosing a capacitor.

Related Technology Terms

  • Dielectric Material
  • Electric Charge Storage
  • Capacitance
  • Electrostatic Field
  • Series and Parallel Connections

Sources for More Information


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