What is the role of electrolytic capacitors in switching power supplies
The functions of electrolytic capacitors in switching power supplies are: bypass, decoupling, filtering, and energy storage.
1. The bypass capacitor is an energy storage device that provides energy for local devices. It can equalize the output of the voltage regulator and reduce the load demand. Like a small rechargeable battery, the bypass capacitor can be charged and discharged to the device.
2. Decoupling: specifically refers to the removal of noise on the power supply pins of the chip, which is generated by the chip itself. Configuring decoupling capacitors can suppress the noise generated by load changes, which is a common practice in the reliability design of printed circuit boards.
3. Filtering: Capacitors convert voltage changes into current changes. The higher the frequency, the greater the peak current, thus buffering the voltage. Filtering is the process of charging and discharging.
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) close to the metal is the dielectric, the cathode is made of conductive material, electrolyte (the electrolyte can be liquid or Solid) and other materials, because the electrolyte is the main part of the cathode, so the name of the electrolytic capacitor. At the same time, the positive and negative of the electrolytic capacitor cannot be connected incorrectly. 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.
Common faults of electrolytic capacitors
Common faults of electrolytic capacitors include capacity reduction, capacity disappearance, breakdown short call and leakage, etc. The capacity change is caused by the gradual drying of the internal electrolyte of the electrolytic capacitor during use or heating up (generally speaking, high temperature and high capacity decrease ), and the breakdown and leakage are generally caused by the applied voltage is too high or the quality of the capacitor itself is not good.
