Variable Capacitor

variable capacitor

Variable Capacitor

A variable capacitor is a device that can be used to store electrical energy. It can be found in a variety of different electronic devices. It is also known as a tuning capacitor.

Variable capacitors are made with 2 sets of hemispherical metal plates that are separated by air gaps. They are connected to a shaft, which can be used to rotate the assembly to change its capacitance values.


A variable capacitor is a device that can hold an electrical charge. Its capacity is measured in farads, and it can be altered by a knob on the capacitor’s body. The knob moves a metal plate that separates the capacitor’s parallel plates. This changes the distance between the plates and alters the capacitor’s capacitance.

A typical variable capacitor consists of two sets of hemispherical metal plates that are separated by an air gap. One set of the plates is fixed, while the other can be rotated to increase or decrease its capacitance. When the rotor is not rotating, the capacitance is maximum. However, when the rotor is rotating, the capacity decreases.

Variable capacitors can be used in a variety of circuits to store energy. Their ability to change their capacity is an advantage over other capacitors, which only store a fixed amount of energy. For example, a variable capacitor can be used to tune radio stations and avoid interference.

The design of a variable capacitor can vary from manufacturer to manufacturer. Some use aluminum, while others have a polymer film between the fixed and moving plates. There are also ceramic, mica, and plastic capacitors. Some are even organically sealed. All of these factors can affect the capacitor’s performance. However, if the capacitor’s moving and fixed plates collide, it may generate electrostatic noise.


A variable capacitor is a type of electronic component that can be adjusted to change battery management ic its capacitance value. It consists of two parallel plates that are separated by an insulating material. The movable plate has a semi-circle shape, and it can be rotated to adjust the value of the capacitor. These capacitors are used in a wide range of applications, from radios and tuning circuits to frequency synthesizers and filters.

In addition to being adjustable, these capacitors are mechanically dependable. They can be repaired easily if they have been damaged. A multimeter can be used to check whether the movable and fixed parts of a variable capacitor are in contact with each other. This can help determine if there is an issue with the film.

The voltage of a variable capacitor depends on its capacitance, frequency rating, and leakage current. The frequency rating indicates how much power the capacitor can store, and the leakage current is the amount of electricity that Programmable Logic Device component escapes from the capacitor when there is no voltage applied. The voltage of a variable capacitor can also be determined by measuring the resistance of its plates.

The voltage of a variable capacitor can also vary depending on the temperature. This is because the temperature changes the thickness of the depletion layer of the semiconductor diode. Although any diode can exhibit this effect, devices sold as varicaps are designed with large junction areas and a doping profile that maximizes capacitance.


There are a number of things that can affect the temperature of a variable capacitor. These include shock, vibration, contamination, and moisture. The dielectric used in the capacitor can also impact its performance. Some dielectrics have a very large temperature coefficient, while others have a linear temperature behavior. These factors can lead to a significant difference in the capacitance of a capacitor.

Variable capacitors are used in a variety of applications, including tuning radios and impedance matching. They can be made from a variety of materials, including ceramics and polymers. They are also available in various sizes and types.

The most common type of variable capacitor is a ceramic one, which is used in most electronic circuits. It has a ceramic core and is connected to an AC voltage source. This allows the user to adjust the capacity to match their requirements.

Another type of variable capacitor is a liquid filled one. This uses a mixture of different fluids to separate the conductors. This allows the user to change the operating characteristics of the capacitor by changing the composition of the liquid. Liquid filled capacitors are also more resistant to vibration and shock, making them a good choice for high-frequency applications. They can also withstand a higher voltage than solid-state capacitors. However, they have a higher failure rate and require a more expensive manufacturing process.


The weight of a variable capacitor can vary depending on the number of plates and the dielectric used. It is also based on the diameter of the plate and the size of the holes. Generally, smaller holes will weigh less than larger ones. Similarly, the thickness of the plates will affect the weight. The weight of a capacitor can also depend on its packaging. For example, a plastic package will weigh less than an aluminum one.

A variable capacitor is a type of capacitor that uses two metal plates and an air dielectric between them to store electric potential energy and voltage. This energy can then be released as electric current. The capacity of a variable capacitor can be changed by rotating the shaft that runs through it. Typical capacitors have many plates, with 7 on one side and 6 on the other. As the shaft is rotated, the 7 plates can move closer or farther away from the 6 stationary plates.

The present utility model relates to a variable capacitor that has a plurality of electrode plates not communicated with each other, and a plurality of lead wires (pin) which are not connected with each other. The present embodiment has the advantages of being large in the variable ranges of capacitance, volume is little, and light in weight, and it can be used for electronic circuits that need capacitance changing and electrical products, especially power line carrier communication equipment.

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