Talking about electrolytic capacitors, we must not know more about his role.
1, Filtering, in the power circuit, the rectifier circuit turns the alternating current into a pulsating direct current, and after the rectifier circuit is connected to a larger capacity electrolytic capacitor, using its charge and discharge characteristics (storage energy) to make the rectified The pulsating DC voltage becomes a relatively stable DC voltage.
In practice, in order to prevent the power supply voltage of each part of the circuit from changing due to load changes, there are typically tens to hundreds of microfarads of electrolytic capacitors at the output of the power supply and the power input of the load. Since the large-capacity electrolytic capacitor generally has a certain inductance, the high-frequency and pulse-interference signals cannot be effectively filtered out, so a capacitor with a capacity of 0.001--0.lpF is connected in parallel at both ends to filter out the high-frequency. And pulse interference.
2, Coupling effect: In the process of transmission and amplification of low-frequency signals, in order to prevent the static working points of the two-stage circuit from interacting with each other, capacitor coupling is often used. In order to prevent the loss of the low frequency component of the signal in the signal, the electrolytic capacitor with a large capacity is generally used.