What is the role of electrolytic capacitors in switching power supplies?
The role of electrolytic capacitors in switching power supplies are: bypass, decoupling, filtering, energy storage.
1, bypass capacitors are energy storage devices that provide energy to the local device, which can even out the output of the regulator and reduce the load demand. Like a small rechargeable battery, bypass capacitors can be charged and discharged to the device.
2, decoupling: specifically refers to the removal of noise on the chip power tube pin, the noise is generated by the chip itself work. Configuration decoupling capacitors can be suppressed due to load changes in the noise generated by the printed circuit board is a conventional practice of reliability design.
3, filtering: capacitors convert voltage variations into current changes, the higher the frequency, the greater the peak current, thus buffering the voltage. Filtering is the process of charging, discharging.
Electrolytic capacitor is a kind of capacitor, metal foil for the positive pole (aluminium or tantalum), and the positive pole close to the metal oxide film (aluminium oxide or tantalum pentoxide) is the dielectric, the cathode by the conductive material, electrolyte (electrolyte can be liquid or solid) and other materials together, because the electrolyte is the main part of the cathode, electrolytic capacitor is therefore named. At the same time electrolytic capacitors positive and negative can not be connected to the wrong. Aluminium electrolytic capacitors can be divided into four categories: leaded aluminium electrolytic capacitors; bullhorn aluminium electrolytic capacitors; bolted aluminium electrolytic capacitors; solid state aluminium electrolytic capacitors.
Common faults of electrolytic capacitors
Common faults of electrolytic capacitors are capacity reduction, capacity disappearance, breakdown and leakage, etc., in which the capacity change is caused by the electrolytic capacitor in the process of using or warming up its internal electrolyte gradually dry up (generally said that the high temperature capacity reduction), and breakdown and leakage are generally caused by the added voltage is too high or the capacitor itself is not of good quality.
