Capacitors are electronic components used to store energy and whose purpose is to prevent sudden changes from occurring in a circuit due to a rise or fall in voltage.
- A capacitor is an electronic component that stores and releases electrical energy, consisting of two conductive plates separated by an insulating material, known as a dielectric.
- It can temporarily hold and discharge a charge, playing a crucial role in electronic circuits for energy storage and filtering.
What is a capacitor?
A capacitor, also called a capacitor, is an electronic component that can store energy through an electric field. This is a device classified as passive, as it cannot amplify or cut off the flow of electricity in the circuit.
Generally, capacitors are used as direct current filters, in this way, they prevent sudden changes from occurring in the circuit due to a rise or fall in voltage.
Plastic foil capacitor
This type of capacitor is usually larger than average , has a fairly stable capacitance, and has better insulation. They have a series of plastic sheets interspersed among other metal ones.
Metallized foil capacitor
This capacitor has a metal sheet that is deposited directly on the plastic sheet. This capacitor has the quality of being able to protect itself against voltage rise. Once it occurs, the electric arc disappears through the metal sheet, eliminating defects due to overvoltage.
This consists of several sheets of mica and aluminum that are placed alternately, these sheets are protected by a layer of molded plastic. It has low leakage current and has high stability . This type of capacitor has a fairly high cost on the market.
This type of capacitor has a dielectric made of polyester. Some are metallic, this has the function of reducing their size considerably. It has very little current loss and plenty of potential capacity.
It has a very high capacitance and its price is relatively low . Their disadvantage is that they have a high leakage current and a fairly low breakdown voltage. These capacitors are polarized, and have the risk of exploding if they are connected with their polarity reversed , so care must be taken in their installation. They are used in power supplies.
They consist of a sealed aluminum tube where the capacitor is located . In addition, they have a safety valve that lets gases escape in case the device boils, avoiding the risk of explosion.
Spin Variable Capacitors
This type is widely used in radio broadcasting devices for tuning frequencies. Its mechanism allows the capacitor plates to move with the help of an axis and in this way the capacitance varies. They are manufactured with an air dielectric . Plastic parts are used to reduce the separation between the plates and increase the dielectric constant. Furthermore, this considerably reduces its size.
Silver mica capacitors
They are manufactured with a thin layer of silver on the mica dielectric . This type of capacitor is quite stable depending on the time of use. Its main advantage is that it has a fairly low tolerance, generally less than 1%. It has a good temperature coefficient and very good resistance.
Their main disadvantage is that they do not have much capacitance and their cost is high . These capacitors are used in resonant and high frequency circuits due to their stability. They are also used in high voltage circuits due to their good insulation.
These capacitors are made of thin strips of metal conductors, separated by a dielectric made of wax paper. They have a very good capacitance range and resist high voltages , which is why they are used in high-capacity circuits.
Their main disadvantage is that they have a high leakage rate, making them inappropriate for the use of alternating current. They have a tolerance below 10% and cannot be used in synchronized and precision circuits.
This type of capacitor has almost zero inductance and loss . Its dielectric constant is quite high. The ceramic used in these capacitors increases their capacitance and reduces the dimensions they occupy.
They have the disadvantage that they are highly sensitive to temperature and voltage variations . That is why they should not be used in unstable or high voltage circuits, since there can be many variations and high temperatures.
10 Important Functions Perform By Capacitors:
- Energy Storage:
- Timing Elements
- Coupling and Decoupling
- Pulse Conditioning
- Tuning and Oscillation
- Voltage Regulation
- Motor Start Capacitors
- Signal Processing
- Power Factor Correction
Applications of Capacitors in Daily Life:
- Capacitors find diverse applications across electronic circuits and systems.
- In power supply circuits, they serve to filter and stabilize voltages, ensuring a continuous and reliable DC output.
- Capacitors are integral components in timing circuits, influencing the frequency and duration of signals in applications such as oscillators and pulse generators.
- They also play a crucial role in coupling and decoupling signals, allowing the transmission of AC signals while blocking DC components.
- Capacitors contribute to energy storage, acting as temporary reservoirs that release stored energy when needed, as seen in flash photography or electric motor starting.
Additionally, capacitors are employed in smoothing and conditioning electrical pulses, tuning circuits, and enhancing the power factor in electrical systems, showcasing their versatility across a wide range of electronic and electrical applications.