How is the energy storage of capacitors achieved and what are the typical applications?
A capacitor is composed of two electrodes and the dielectric material between them. The dielectric material is a kind of dielectric. When placed in an electric field between two parallel plates with equal amounts of opposite charges, due to polarization, polarized charges are generated on the surface of the dielectric, thereby increasing the charges bound to the plates accordingly to maintain the potential difference between the plates unchanged. This is the reason why capacitors have capacitance characteristics. The electric charge Q stored in a capacitor is equal to the product of the capacitance C and the potential difference U between the electrodes. The capacitance is proportional to the plate area and the dielectric constant ε of the dielectric material, and inversely proportional to the thickness of the dielectric material (that is, the distance between the plates).
Charging and discharging are the basic functions of capacitors:
Charging The process of charging a capacitor to make it carry electric charges (store electric charges and electrical energy) is called charging. At this time, one of the two plates of the capacitor always carries positive charges, and the other plate carries an equal amount of negative charges. Connect one plate of the capacitor to the positive pole of a power supply (such as a battery pack), and the other plate to the negative pole of the power supply. Then the two plates will respectively carry equal amounts of opposite charges. After charging, an electric field is formed between the two plates of the capacitor, and the charging process stores the electrical energy obtained from the power supply in the capacitor.
Discharging The process of making a charged capacitor lose electric charges (release electric charges and electrical energy) is called discharging. For example, connect the two poles of a capacitor with a wire, and the charges on the two poles neutralize each other, and the capacitor will release electric charges and electrical energy. After discharging, the electric field between the two plates of the capacitor disappears, and the electrical energy is converted into other forms of energy.
