Capacitors are electrical capacitors.
If we go to the dictionary of the Royal Spanish Academy ( RAE ) 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 composed 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 to store electrical charges .
How a capacitor works
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.
A capacitor is made up of two conductors separated by a sheet that stores the electrical charge.
Types of dielectrics
There are various 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, which is why it can function adequately at high frequencies.
Mica is another of the materials used as a dielectric for capacitors, 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. A sheet of this material is placed in the mica capacitors and aluminum is placed on top of it; Then many of them are stacked and their ends are soldered to the terminals. Although 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 paper subjected to some treatment that increases insulation and reduces hygroscopicity for the dielectric, such as bakelized and waxed paper. To make it, you must stack a pair of paper tapes, one aluminum tape and, finally, two more paper tapes; Everything is rolled into a spiral and, that's it.
Self-healing and electrolytic capacitors
Self-healing capacitors also use paper, and their application is in industrial environments. If an overload occurs that exceeds the stiffness of the dielectric, the paper cracks and this causes a short circuit between the aluminum sheets.
On the other hand, there are electrolytic capacitors , which use an electrolyte as the first armor. If an adequate amount of voltage is applied, it provides an insulating layer, generally of aluminum oxide and of a very thin thickness, on a second armor, which allows very high capacities to be achieved.
latent mechanical energy
Capacitors do not actually store current or electrical charge: what they store is latent mechanical energy . When they are introduced into an electrical circuit , specifically they do function as a device that conserves the electrical energy obtained during the charging period, after which said energy is released by the capacitor.
Electrical capacity is called capacitance ; that is, the property of an element to conserve an electric charge. In the case of capacitors, capacitance is equivalent to the level of electrical energy that it conserves according to the difference in electrical potential.