Analysis of the meaning of commonly used capacitors in different circuits

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Analysis of the meaning of commonly used capacitors in different circuits [Copy link]

Capacitor is a kind of energy storage element, which has the characteristics of "blocking direct current and passing alternating current, and passing high frequency and negative low frequency". In order to understand and identify capacitors in different circuits, people have given it many names according to its role in the circuit. Understanding these names and roles is helpful for reading diagrams. The following is the meaning of some common names introduced by Electrician's Home. 1. Filter capacitor It is connected in parallel between the positive and negative poles of the circuit to remove the useless alternating current in the circuit. Generally, large-capacity electrolytic capacitors are used, and other fixed capacitors are also used. 2. Decoupling capacitor is connected in parallel between the positive and negative poles of the circuit to prevent parasitic oscillation caused by the positive feedback path formed by the internal resistance of the power supply. 3. Coupling capacitor is connected between the signal source and the signal processing circuit or between the two-stage amplifier to block direct current and allow alternating current or pulsating signal to pass through, so that the DC operating points of the amplifiers do not affect each other. 4. Bypass capacitor is connected in parallel between the two ends of the resistor or directly connected from a certain point to the common telecommunication to set a path for the alternating or pulsating signal in the alternating and direct current signals to avoid the voltage drop caused by the alternating component when passing through the resistor. 5. The neutralizing capacitor is connected between the base and collector of the transistor to overcome the self-excited oscillation caused by the capacitance between the transistor electrodes. 6. The tank capacitor (tuning capacitor) is a capacitor connected to both ends of the resonant circuit or the oscillation circuit coil. 7. The padding capacitor is a capacitor that can reduce the frequency range of the oscillation signal in the circuit and significantly increase the oscillation frequency at the low frequency end. It is connected in series with the tank main capacitor. 8. The compensation capacitor is a capacitor that can expand the frequency range of the oscillation signal in the oscillation circuit. It is connected in parallel with the main capacitor to play an auxiliary role. 9. The reverse capacitor is connected in parallel between the collector and emitter of the line output tube to generate the reverse capacitor of the line scanning sawtooth wave. 10. The bootstrap boost capacitor uses its energy storage to increase the potential of a certain point in the circuit, making its potential value higher than the power supply voltage for that point. 11. The "S" correction capacitor is connected in series in the deflection coil loop to correct the extension distortion on both sides. 12. The frequency stabilizing capacitor is a capacitor used to stabilize the oscillation frequency in the oscillation circuit. 13. Timing capacitor is a capacitor connected in series with resistor R in the RC timing circuit to jointly determine the length of time. 14. Step-down current limiting capacitor is connected in series in the AC circuit to divide the voltage and limit the current of the capacitive reactance of the AC. 15. Shortening capacitor is a capacitor connected in series in the UHF high-frequency head to shorten the length of the oscillation inductor. 16. Clapp capacitor is a capacitor connected in series with the oscillation inductor coil in the capacitor three-point oscillation circuit to eliminate the influence of the transistor junction capacitance and improve the frequency stability. 17. Sila capacitor is a capacitor connected in parallel at both ends of the oscillation inductor coil in the capacitor three-point oscillation circuit to eliminate the influence of the transistor junction capacitance and make it easier to oscillate the oscillation frequency. 18. Acceleration capacitor is connected in the oscillation feedback circuit to accelerate the positive feedback process and increase the oscillation amplitude. 19. Pre-emphasis capacitor is a capacitor in the RC network that appropriately increases the high-frequency component in order to prevent the audio modulation signal from attenuating or losing the high-frequency component during modulation. 20. The de-emphasis capacitor is a capacitor in an RC network that attenuates the high-frequency components of the audio signal that have been pre-added and boosted, along with the noise, to restore the original appearance of the accompanying audio signal. 21. The amplitude stabilization capacitor is used in the frequency detector to stabilize the output signal amplitude. 22. The bright spot elimination capacitor is a capacitor used in the auxiliary circuit of the cathode ray tube to eliminate the bright spot when the power is turned off. 23. The phase shifting capacitor is a capacitor used to change the phase of the AC signal. 24. The feedback capacitor is a capacitor connected across the input and output terminals of the amplifier to feedback the signal. 25. The soft start capacitor is usually connected to the base of the power switch tube to prevent the surge current or voltage added to the switch base from being too large when the power is turned on and damaging the switch tube. 26. The starting capacitor is connected in series with the auxiliary winding of the single-phase motor to provide the motor auxiliary winding with a phase-shifted AC current for starting. When the motor is running normally, it is disconnected from the auxiliary winding. 27. The running capacitor is connected in series with the auxiliary winding of the single-phase motor to provide the motor auxiliary winding with a phase-shifted AC current. When the motor is running normally, it is still connected in series with the auxiliary winding in the circuit. AC safety ceramic capacitors are used to prevent antenna radio wave interference in the AC circuit of electronic equipment, to prevent power supply noise of household appliances and other equipment, to prevent electric shock when equipment fails, and other electronic products. 28. High-frequency low-voltage ceramic capacitors CC1 series is a type of high-frequency low-voltage ceramic capacitors, used in places with low loss and high capacitance stability or in places where the temperature coefficient is clearly specified. Such as: resonant circuit, high-frequency bypass, temperature compensation, control circuit time constant components, coupling components with high stability requirements. CC81 series is a type of high-frequency high-voltage ceramic capacitors, used in high-voltage resonant circuits with UR≥0.63KV or above, or used in places with low loss and capacitance stability or in places where the temperature coefficient is clearly specified. CT1 series is a type of low-frequency band low-voltage ceramic capacitor, used in electrical appliances with low requirements for tgs value and capacitance stability, such as low frequency, coupling, filtering, decoupling, etc., and can also be used as a time constant component of the control circuit. CT81 series is a type of low-frequency high-voltage ceramic capacitor. Used in high-voltage bypass and coupling circuits, with large dielectric constant, large capacity and low loss. CS1 series - Class III low-frequency and low-voltage ceramic capacitors are used for broadband bypass coupling in ultra-high frequency and very high frequency circuits. They have the characteristics of high dielectric constant, small size and large capacity. CT82 series - Ultra-high voltage ceramic capacitors are mostly used in high-voltage bypasses with ultra-high requirements for withstand voltage. They have the characteristics of small size, good temperature and humidity resistance, and low loss.