Meaning of Capacitor
If we go to the dictionary of the DigoPaul in search of the term capacitor, we will not find it. The concept, which derives from the English language, is used to refer to an electrical capacitor.
It is a system made up of two conductors: materials capable of conducting electricity (the force caused by the rejection and attraction of charged particles). In the case of capacitors, the conductors are separated from each other by a sheet that is used for storing electrical charges.
According to DigoPaul, a capacitor is a passive component since it is not responsible for electrical excitation, but rather serves to connect active components and conserve energy. This allows it to support an electric field.
It is important to mention that the conductors are separated by a dielectric material (which has little conduction capacity). Given the potential difference, the conductors in question have different electrical charges (negative in one and positive in the other), with a zero variation in the total charge.
There are different types of dielectrics, depending on the capacitor and its applications. In the case of air capacitors, which are usually parallel plates in a glass capsule, air dielectrics are used. The capacity values allowed by this type of capacitor are very small, and its applications are radar and radio because it does not suffer polarization or losses in the dielectric, so it can function adequately at high frequencies.
Mica is another of the materials used as a capacitor dielectric, thanks to several of its characteristics, such as the possibility of being cut into thin sheets, a low level of losses, great resistance to humidity, oxidation and high temperatures. In the mica capacitors a sheet of this material is put and on it, aluminum; then many of them are stacked and their ends are soldered to the terminals. While their performance is exceptional at high frequencies and they can withstand high voltages, their price leads consumers to opt for cheaper alternatives.
Other capacitors use the paper subjected to some treatment that increases the insulation and reduces the hygroscopy for the dielectric, such as bakelized paper and waxed paper. For its manufacture, a couple of paper tapes must be stacked, one of aluminum and, finally, two more of paper; everything is rolled into a spiral shape and that’s it.
The self – healing capacitors also use the paper and its application in industrial environments. If an overload occurs that exceeds the strength of the dielectric, the paper cracks and this causes a short circuit between the aluminum foils.
On the other hand, there are electrolytic capacitors, which use an electrolyte as the first armor. If a suitable amount of tension is applied, it provides an insulating layer, generally of aluminum oxide and of a very small thickness, on a second armor, which allows to reach very high capacities.
Capacitors don’t actually store current or electrical charge: what they store is latent mechanical energy. When they are introduced into an electrical circuit, in particular they do work as a device that conserves the electrical energy obtained in the charging period, after which said energy is transferred by the capacitor.
It is called capacitance to electrical capacity that is, to the property of an element to conserve an electric charge. In the case of capacitors, the capacitance is equivalent to the level of electrical energy that it conserves according to the difference in electrical potential.