Analysis of the meaning of commonly used capacitors in different circuits

Filter capacitor:

It is connected in parallel between the positive and negative poles of the circuit to remove the useless ac current in the circuit. Generally, large-capacity electrolytic capacitors are used, and other fixed capacitors are also used.

Decoupling capacitor:

Connected in parallel between the positive and negative poles of the circuit, it can prevent parasitic oscillation caused by the positive feedback path formed by the internal resistance of the power supply.

Coupling capacitor:

It is connected between the signal source and the signal processing circuit or the two-stage amplifier to isolate the DC power and allow the AC power or pulsation signal to pass through so that the DC operating points of the two amplifiers do not affect each other.

Bypass capacitor:

Connect it in parallel to both ends of the resistor or directly jump from a certain point to the common telecommunications to set up a path for the AC or pulsating signal in the AC and DC signals to avoid the voltage drop caused by the AC component when passing through the resistor.

Neutralizing Capacitor:

Connected between the base and collector of the triode, it is used to overcome self-oscillation caused by the capacitance between the triodes.

Tank capacitor (tuning capacitor):

A capacitor connected across the coil of a resonant circuit or oscillating circuit.

Pad trimming capacitor:

In the circuit, there is a capacitor that can reduce the frequency range of the oscillation signal and significantly increase the oscillation frequency at the low-frequency end. It is connected in series with the main capacitor of the tank circuit.

Compensation capacitor:

In the oscillation circuit, a capacitor can expand the frequency range of the oscillation signal. It plays an auxiliary role in parallel with the main capacitor.