Flat capacitor and its device

Two flat plates arranged parallel to each other and separated by a dielectric form a flat capacitor. This is the simplest representative of capacitors, which are designed to accumulate dissimilar energy. If the plates are informed of a charge that is equal in magnitude but different in modulus, then the electric field strength between the conductors will be doubled. The ratio of the charge of one of the conductors to the voltage between the plates of the capacitor is called the electrical capacity:

C = q / U

If the arrangement of the plates is unchanged, then the capacitance of the capacitor can be considered a constant for any charge of conductors. In the international measurement system, the unit of electrical capacity is Farad (F). A flat capacitor has a voltage equal to the sum of the voltages created by the conductors (E ₁ + E ₂ ... + E _n ). Values are vector. The value of the electrical capacity is directly proportional to the area of the plates and inversely proportional to the distance between them. This means that in order to increase the capacitance of the capacitor, it is necessary to make the area of the plates larger, while decreasing the distance between them. Depending on the dielectric used, the flat capacitor can be:

• Paper.
• Mica.
• Polystyrene.
• Ceramic.
• The air.

The principle of the device will be considered on the example of a paper condenser. Paper treated with paraffin is used in this case as a dielectric. A dielectric is laid between two stripes of foil, which serve as conductors. The entire structure is folded into a roll into which the terminals are inserted to connect to the electrical circuit. This model is placed in a ceramic or metal case. A flat air condenser and other types of charge accumulators are of a similar design, only as a dielectric medium are materials used in honor of which the capacitor is named. When solving problems in which it is necessary to find the required quantities, do not forget to use the value characterizing the dielectric, the dielectric permittivity of the medium.

In radio engineering, liquid and dry types of capacitors are used. Liquid capacitors are an electrolyte solution in which an aluminum oxide plate is placed. This substance is in the metal case. A solution of boric acid and some other mixtures are used as the electrolyte. The dry form of the accumulators is made by folding three bands, one of which is aluminum, the other is made of metal, and between them is a gauze layer impregnated with a viscous electrolyte. The roll is placed in an aluminum casing and is filled with bitumen. The flat capacitor has a wide range of applications and low cost. Unfortunately, these models will not replace us batteries, because the energy of the flat capacitor is very small, and the charge very quickly "leaks". They are not suitable as sources of electricity, but have one advantage - when charging through a circuit of low resistance instantly give up the stored energy.