What is the difference between electrolytic capacitors and ordinary capacitors?

First, the composition is different
1. Electrolytic capacitor: The metal foil is the positive electrode (aluminum or tantalum bai), and the metal oxide film (aluminum oxide or tantalum pentoxide) close to the positive electrode is the dielectric, and the cathode is made of conductive materials and electrolyte (the electrolyte can be liquid or solid) Together with other materials, the electrolyte is the main part of the cathode.
2. Ordinary capacitance: An isolated conductor forms a capacitance with infinity, and the conductor grounding is equivalent to being connected to infinity and connected to the earth as a whole.

Second, the characteristics are different
1. Electrolytic capacitor: The capacitance per unit volume is very large, tens to hundreds of times larger than other types of capacitors. The rated capacity can be very large, and it can easily be tens of thousands of μf or even a few f (but not comparable to the electric double layer capacitance).
2. Ordinary capacitors: The types of capacitors can be divided into principle: non-polar variable capacitors, non-polar fixed capacitors, polar capacitors, etc. From the material, they can be divided into: CBB capacitors (polyethylene), polyester capacitors, porcelain Chip capacitors, mica capacitors, monolithic capacitors, electrolytic capacitors, tantalum capacitors, etc.

Application of electrolytic capacitors:
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. Its disadvantages are medium loss, large capacity error, poor high temperature resistance, and prone to failure due to long storage time.
The polarity of the electrolytic capacitor, pay attention to the "-" on the side of the electrolytic capacitor for negative and "+" for positive. If the positive and negative electrodes are not marked on the electrolytic capacitor, it can also be judged according to the length of its pins. It is the positive pole and the short leg is the negative pole.