in the power supply circuit, the commutation circuit changes the alternating current into the pulsating direct current, and after the commutation circuit, a large capacity electrolytic
capacitor is connected. by using its charging and discharging characteristics, the pulsating direct current voltage after the commutation becomes a relatively stable direct current voltage.
in practice, in order to prevent the supply voltage of each part of the circuit from changing due to the load change, dozens to hundreds of micromethods of electrolytic capacitors are connected to the output of the power supply and the input of the load.
because the large capacity electrolytic capacitor generally has a certain inductance, which can not effectively filter the high frequency and pulse interference signals, a capacitor with a capacity of 0.001-0.lpf is paralleled at both ends of the capacitor to filter the high frequency and pulse interference
coupling effect: in the process of low-frequency signal transmission and amplification, in order to prevent the static working points of the front and rear two-stage circuits from affecting each other, capacitance coupling is often used. in order to prevent the loss of low-frequency components in the signal from being too large, electrolytic capacitors with large capacity are generally used.