I. Capacitor Theory
(1) Basic Structure of a Capacitor
A capacitor is a device that uses a medium (dielectric) between two electrode plates to store electricity. In diagram 1, this dielectric employs a polar compound. Because this polarization is stronger, an electrical field of the same strength can produce more polarized electrical charges, fulfilling a small volume, high capacity goal.
(2) Calculating the capacity of a capacitor
The capacity of a capacitor and the effectiveness of electrodes are in direct proportion to Area S, and the distance between the electrodes is in inverse proportion to d. This quantity of electricity is calculated according to the formula:
An electrolytic capacitor uses Aluminum Oxide as the dielectric, with its rate¢G`= 8-10. In comparison, the capacities of normal capacitors don!|t have such a high value, because electrical erosion occurs on the surface of the aluminum, increasing the surface accumulation (S). This electrical / chemical treatment transforms the Aluminum Oxide, allowing it to retain a higher voltage and making every unit volume of accumulated CV bigger than the unit volume of other capacitors. Other capacitors cannot compare; as the older electrolytic capacitors are small and the costs are low, they are more widely used.
II. The Structure of Electrolytic Capacitors
Features of an electrolytic capacitor (see diagram on the left):
(1) Colorless substances (semi-finished product that uses a metal foil fore the anode, electrolytic paper, and coil-type anode structure, which is placed in an electrolyte solution)
(2) Terminal to connect cable to anode structure
(3) The container is sealed tightly with an aluminum cover.
(4) Characteristics of capacitors
Capacitors that can hold and discharge electricity have the following characteristics:
a. Capacitors can, within a short period of time, produce static electricity and electrokinetic energy. Its short circuit, electrical current has 1000 times the capacity of a normal battery.
b. A capacitor!|s capacity small, but it can take in a large amount of electrical power; in other words, the electrical charge / discharge time is very short, but the efficiency rate is extremely high.
c. In an AC circuit, electric current meters advance the voltage benchmark by 90C¢Xthe voltage of a produced electrical current is faster than the voltage benchmark by 90C¢X, acting as a phase modifier.
d. The capacitive resistance and frequency rate have a direct relationship: Xc = 1/2¢Gk fc. The higher the frequency rate, the lower the capacitive resistance, and vice versa.
