Principle and calculation formula of capacitors and conversion of capacitor units

Principle of capacitors

In production and practical life, scientists have found that when a voltage is applied between two insulated conductors, the conductor connected to a high potential can accommodate positive charges, while the conductor connected to a low potential can accommodate negative charges. From this, it can be seen that the whole composed of the above-mentioned conductor and insulation has the ability to accommodate charges, which is called capacitance. And this whole is called a capacitor.

Capacitor calculation formula

Practice has proven that the situation where any capacitor holds charge is similar to the situation where a basketball holds gas. The higher the atmospheric pressure of a basketball, the more gas it can contain; The higher the voltage applied to a capacitor, the more charge it can hold. In this way, to measure its ability to hold charges, it must be measured at the same voltage. The amount of charge that can be held per unit voltage is called capacitance, represented by C in Farads:

In the above formula, q is the amount of charge that a capacitor can hold when subjected to an external voltage U.

The capacitance of common capacitors in practical use is indicated when they are manufactured, and the number or color ring on the surface of the capacitor element contains the capacitance information. 1 Farad equals 1 Coulomb per volt, meaning that a capacitor with a capacitance of 1 Farad can store an additional 1 Coulomb of charge for every 1 volt increase in potential difference within the normal operating range.

Conversion of capacitance units

The capacity unit of a capacitor is Farad (represented by the letter F), but in practical applications, Farad is too large. The most commonly used methods are microfarads (uF) or skin methods (PF).

1F=1000000 microfarads=106 microfarads (uF)

1uF=1000000 picofarads=106 picofarads (PF)

The size of a capacitor is related to its geometric dimensions and the properties of the dielectric. In addition to capacitors having capacitance, in practice, electrical equipment, circuits, and components all have naturally formed capacitance. Between longer transmission lines, longer cables have capacitance.