The electrolytic capacitor is a kind of capacitor.
The electrolytic capacitor is a kind of capacitor, the metal foil is the positive electrode (aluminum or tantalum), the oxide film (aluminum oxide or tantalum pentoxide) that is close to the positive electrode is the dielectric, and the cathode is made of conductive material, electrolyte (the electrolyte can be liquid or Solid) and other materials together, because the electrolyte is the main part of the cathode, so the electrolytic capacitor is named. At the same time, the positive and negative electrolytic capacitors should not be wrongly connected.
Aluminum electrolytic capacitors can be divided into four categories: lead-type aluminum electrolytic capacitors; horn-type aluminum electrolytic capacitors; bolt-type aluminum electrolytic capacitors; solid aluminum electrolytic capacitors.
The working principle of electrolytic capacitors: Electrolytic capacitors are usually made of metal foil (aluminum/tantalum) as the positive electrode, and the insulating oxide layer of the metal foil (aluminum oxide/tantalum pentoxide) as the dielectric. Electrolytic capacitors are divided into different positive electrodes. Aluminum electrolytic capacitors and tantalum electrolytic capacitors. The negative electrode of aluminum electrolytic capacitors consists of thin paper/film or electrolyte polymer soaked in an electrolyte (liquid electrolyte); the negative electrode of tantalum electrolytic capacitors is usually manganese dioxide. Electrolytic capacitors get their name because they use electrolytes as negative electrodes (note the distinction from dielectrics).
Application of electrolytic capacitors:
Polar electrolytic capacitors usually play the role of power supply filtering, decoupling, signal coupling, time constant setting, and DC blocking in power supply circuits or intermediate frequency and low frequency circuits. Generally, it cannot be used in AC power supply circuits. When used as filter capacitors in DC power supply circuits, the anode (positive pole) should be connected to the positive terminal of the power supply voltage, and the cathode (negative pole) should be connected to the negative terminal of the power supply voltage. , otherwise the capacitor will be damaged.
Non-polar electrolytic capacitors are usually used in speaker divider circuits, TVS correction circuits and single-phase motor starting circuits.
Electrolytic capacitors are widely used in household appliances and various electronic products, with a large capacity range, generally 1~33000μF, and a rated working voltage range of 6.3~700V. The disadvantage is that the medium loss, the capacity error is large (the maximum allowable deviation is +100%, -20%), the high temperature resistance is poor, and the storage time is long and it is easy to fail.