The so-called capacitor is an electronic component that holds and releases electric charge. The basic working principle of a capacitor is charging and discharging, and of course it also has rectification, oscillation and other functions. In addition, the structure of the capacitor is very simple, mainly composed of two positive and negative electrodes and an insulating medium sandwiched in between, so the capacitor type is mainly determined by the electrodes and the insulating medium.

01. Filter capacitor: It is connected between the positive and negative poles of the DC voltage to filter out unnecessary AC components in the DC power supply and smooth the DC power. Large-capacity electrolytic capacitors are usually used, and other capacitors can also be connected in parallel in the circuit. Type of small-capacity capacitor to filter out high-frequency alternating current.

02. Decoupling capacitor: Connect in parallel between the positive and negative poles of the power supply of the amplifier circuit to prevent parasitic oscillation caused by positive feedback caused by the internal resistance of the power supply.

03. Bypass capacitor: In the circuit of AC and DC signals, the capacitor is connected in parallel to both ends of the resistor or connected to the common potential from a certain point of the circuit to set a path for the AC signal or pulse signal to avoid AC signal components. Voltage drop attenuation occurs through resistors.

04. Coupling capacitor: In AC signal processing circuits, it is used to connect the signal source and the signal processing circuit or as an inter-stage connection between two amplifiers. It is used to cut off DC and allow AC signals or pulse signals to pass through, so that the DC in the front and rear amplifier circuits can The working points do not affect each other.

05. Tuning capacitor: Connected to both ends of the oscillation coil of the resonant circuit, it plays the role of selecting the oscillation frequency.

06. Pad capacitor: An auxiliary capacitor connected in series with the main capacitor of the resonant circuit. Adjusting it can reduce the frequency range of the oscillation signal and significantly increase the oscillation frequency at the low-frequency end.

Crystal oscillator circuit and its equivalent circuit.

07. Compensation capacitor: An auxiliary capacitor connected in parallel with the main capacitor of the resonant circuit. Adjusting this capacitor can expand the frequency range of the oscillation signal.

08. Neutralizing capacitor: Connected in parallel between the base and emitter of the triode amplifier to form a negative feedback network to suppress self-oscillation caused by the capacitance between the triode electrodes.

09. Frequency stabilizing capacitor: In the oscillation circuit, it plays the role of stabilizing the oscillation frequency.

10. Timing capacitor: It is connected in series with the resistor R in the RC time constant circuit and jointly determines the length of the charge and discharge time.

11. Acceleration capacitor: connected to the oscillator feedback circuit to accelerate the positive feedback process and increase the amplitude of the oscillation signal.

12. Shorten the capacitor: In the UHF high-frequency head circuit, the capacitor is connected in series to shorten the length of the oscillation inductor.

13. Krabo capacitor: In the capacitor three-point oscillation circuit, the capacitor connected in series with the inductor oscillation coil plays the role of eliminating the influence of the transistor junction capacitance on frequency stability.

Krabo oscillator.

14. Tin pull capacitor: In the capacitor three-point oscillation circuit, the capacitor connected in parallel with both ends of the inductor oscillation coil can eliminate the influence of the transistor junction capacitance, making it easy for the oscillator to start oscillating at the high-frequency end.

15. Amplitude stabilizing capacitor: In the frequency discriminator, it is used to stabilize the amplitude of the output signal.

16. Pre-emphasis capacitor: In order to avoid attenuation and loss of frequency components during the processing of the audio modulation signal, the RC high-frequency component is set to increase the network capacitance.

17. De-emphasis capacitor: In order to restore the original audio signal, it is required to attenuate the high-frequency components increased by pre-emphasis and noise in the audio signal, and set the RC capacitor in the network.

18. Phase-shifting capacitor: A capacitor used to change the phase of an AC signal.

19. Feedback capacitor: A capacitor connected between the input and output terminals of the amplifier to return the output signal to the input terminal.

20. Step-down current-limiting capacitor: connected in series in the AC circuit, the capacitive reactance characteristics of the capacitor to the AC current are used to limit the current of the AC current, thus forming a voltage dividing circuit.

21. Reverse capacitor: used in the row scan output circuit and connected between the collector and emitter of the row output tube to generate high-voltage row scan sawtooth wave reverse pulse. Its withstand voltage is generally above 1500 volts.

22.S correction capacitor: connected in series in the deflection coil loop, used to correct the extended linear distortion at the edge of the picture tube.

23. Bootstrap boost capacitor: The charging and discharging energy storage characteristics of the capacitor are used to increase the potential of a certain point in the circuit, so that the potential of the point reaches twice the voltage value of the power supply terminal.

24. Elimination point capacitor: It is set in the video amplifier circuit and is used to eliminate the residual bright spots on the picture tube when the power is turned off.

25. Soft-start capacitor: Generally connected to the base of the switching tube of the switching power supply to prevent excessive surge current or excessive peak voltage from being added to the base of the switching tube when the power is turned on, causing damage to the switching tube.

26. Starting capacitor: Connected in series to the secondary winding of a single-phase motor, it provides the motor with a starting phase-shifted AC voltage, and is disconnected from the secondary winding after the motor operates normally.

27. Running capacitor: connected in series with the secondary winding of a single-phase motor to provide phase-shifted AC current to the secondary winding of the motor. When the motor is running normally, it remains connected in series with the auxiliary winding.