The role of capacitance

The name and function of capacitors in different circuits is introduced. A capacitor is a kind of energy storage element. It has the characteristics of blocking direct current and low frequency through high frequency. In order to recognize and identify capacitors in different circuits, they are based on their role in the circuit. Many names have been given to it, and understanding these names and functions is helpful for reading the picture. The meaning of some common names is introduced below. 1. The name and function of filter capacitors in different circuits Introduction Capacitors are a kind of energy storage The component has the characteristic of 'separating the direct current and passing the low frequency through the high frequency'. In order to recognize and identify the capacitors in different circuits, they have given it many names according to their role in the circuit. Understand these names and functions. It is helpful to read the picture. The meaning of some common names is introduced below. 1. The filter capacitor is connected in parallel between the positive and negative electrodes of the circuit to remove the useless AC current in the circuit. Generally, large-capacity electrolytic capacitors are used, and others are also used. 2. The decoupling capacitor is connected in parallel between the positive and negative electrodes of the circuit to prevent parasitic oscillation caused by the positive feedback path formed by the internal resistance of the power supply. 3. The coupling capacitor is connected to the signal source and the signal processing circuit or Between the two amplifiers, it is used to cut off the direct current and allow alternating current or pulsating signals to pass, so that the DC operating points of the believed amplifiers do not affect each other. 4. The bypass capacitor is connected in parallel to the two ends of the resistor or directly connected to the shared telecommunications from a certain point. Set up a path for the AC or pulsating signal in the AC and DC signal to avoid the voltage drop caused by the AC component when passing through the resistance. 5. The neutralization capacitor is connected between the base and collector of the transistor to overcome the capacitance between the transistors. 6. The tank circuit capacitor (tuning capacitor) is connected to the capacitor at both ends of the resonant circuit or the coil of the oscillation circuit. 7. The padding capacitor in the circuit can reduce the frequency range of the oscillating signal, and significantly improve the low-frequency end oscillation The frequency capacitor is connected in series with the main capacitor of the tank circuit. 8. The compensation capacitor is a capacitor that can expand the frequency range of the oscillating signal in the oscillating circuit. It is connected in parallel with the main capacitor to play an auxiliary role. 9. Flyback capacitor parallel Connected between the collector and emitter of the horizontal output tube, it is used to generate a horizontal scanning sawtooth reverse-travel capacitor. 10. The bootstrap boost capacitor uses its energy storage to increase the potential of the circuit so that its potential value is higher than The power supply voltage for this 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 the capacitor used to stabilize the oscillation frequency in the oscillation circuit. 13. The timing capacitor is connected in series with the resistor R in the RC timing circuit to determine the length of the capacitor. 14. The step-down current-limiting capacitor is connected in series in the AC circuit to divide the capacitive reactance of the AC current and limit the current. 15. Shorten the capacitor. This kind of capacitor is a capacitor connected in series in order to shorten the length of the oscillating inductance in the UHF high-frequency head. 16. The Klap capacitor is connected in series to the capacitor of the oscillating inductance coil in the capacitor three-point oscillation circuit, for the influence of the junction capacitance of the water transport transistor, Improve frequency stability. 17. The tin capacitor is in the capacitor three-point oscillation circuit, and is connected to the capacitor at both ends of the oscillating inductance coil, in order to eliminate the influence of the junction capacitance of the transistor and make it vibrate. The more the oscillating frequency, the easier it is to oscillate. 18. The acceleration capacitor is connected to the oscillating feedback circuit to accelerate the positive feedback process and increase the amplitude of oscillation. 19. The pre-emphasis capacitor is to prevent the audio modulation signal from attenuating high-frequency components during modulation. Or lose, and appropriately increase the high-frequency component of the RC network capacitor. 20. The de-emphasis capacitor attenuates the pre-boosted high-frequency component of the audio signal together with the noise, and restores the original appearance of the audio signal RC network 21. The amplitude-stabilizing capacitor is used in the frequency discriminator to stabilize the output signal amplitude. 22. The de-bright spot capacitor is used in the auxiliary circuit of the CRT to eliminate the capacitor that is turned off. 23. The phase shift capacitor is used to change the AC The capacitance of the electrical signal phase. 24. The feedback capacitor is connected to the input and output terminals of the amplifier. The capacitor used to feedback the signal. 25. The soft-start capacitor is usually connected to the base of the power switch to prevent the wave that is added to the base of the switch when it is turned on. The inrush current or voltage is too large to damage the switching tube. 26. The starting capacitor is connected in series to the secondary winding of the single-phase motor to provide the phase-shifting AC current for the secondary winding of the motor. When the motor is running normally, it will be disconnected from the secondary winding. 27. Operation The capacitor is connected in series with the secondary winding of the single-phase motor to provide phase-shifting AC current for the secondary winding of the motor. When the motor is running normally, the secondary winding is still in series with the circuit. The AC safety ceramic capacitor is used to prevent the antenna electric wave in the AC circuit of electronic equipment. Interference, prevent the power noise of household appliances and other equipment, and prevent electric shocks when the equipment fails. 28. High-frequency and low-voltage ceramic capacitors CC1 series are a type of high-frequency and low-voltage ceramic capacitors, which are used for low loss and capacitance. Where high stability is required or where the temperature coefficient is required to be clearly specified. Such as: resonance circuit, high frequency bypass, temperature compensation, control circuit time constant components, and coupling components with high stability requirements. The CC81 series is a class High-frequency and high-voltage ceramic capacitors are used in high-voltage resonant circuits with UR≥0.63KV, or in places with low loss and capacitance stability, or in places where temperature coefficients are clearly required. CT1 series are second-class low-frequency With low-voltage ceramic capacitors, it is used in electrical appliances that do not require high tgs value and capacity stability, such as low frequency, coupling, filtering, decoupling, etc., and can also be used as time constant components for control circuits. CT81 series are second-class low-frequency High-voltage ceramic capacitors. Used in high-voltage bypass and coupling circuits, with large dielectric constant, large capacity and low loss. CS1 series-three types of low-frequency low-voltage ceramic capacitors are used in ultra-high frequency and very high frequency circuits for broadband The use of bypass coupling has 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. It has small size and temperature resistance. , The characteristics of good humidity resistance and low loss.