Gaoyun electric takes you to know capacitance

Ningbo Gaoyun Electric Co., Ltd. is located in Ningbo, a modern port city of China. It is a member of China Electrical Industry Association, specializing in the production of 0.25-2kv medium and low voltage metallized power capacitors. The company has more than 70 employees, 12 professional and technical personnel, more than 30 sets of advanced production power capacitor equipment for filter capacitors, and 3800000 kvar self-healing power capacitors for cylindrical capacitors. Gaoyun company, which grew up with the power capacitor Committee of China electronic technology society, has gone through 20 years of ups and downs. Intelligent capacitors have formed a complete set of scientific management system through entrepreneurship and hard work.

Understand the function of capacitance from its name

Capacitors are almost indispensable energy storage elements in electronic circuits. They have the characteristics of isolating DC, connecting AC and preventing low frequency. It is widely used in coupling, isolation, bypass, filtering, tuning, energy conversion and automatic control circuits. Being familiar with the names and meanings of capacitors in different circuits is helpful for us to understand electronic circuit diagrams.

1. Filter capacitance

It is connected between the positive and negative poles of the DC power supply to filter out the unnecessary AC components in the DC power supply and make the DC level slip. Generally, large capacity electrolytic capacitors are often used, and other types of small capacity capacitors can be connected in the circuit at the same time to filter out high-frequency alternating current.

2. Decoupling capacitance

It is connected between the positive and negative of the power supply of the amplification circuit to prevent the parasitic oscillation caused by the positive feedback formed by the internal resistance of the power supply.

3. Bypass capacitance

In the circuit of AC and DC signal, connect the capacitance at both ends of the resistance or a point of the circuit across the common potential, and set a path for the AC signal or pulse signal to avoid the voltage drop attenuation of the AC signal component due to the resistance.

4. Coupling capacitance

In the AC signal processing circuit, it is used to connect the signal source and the signal processing circuit or as the stage connection of two amplifiers, to cut off the DC, let the AC signal or the pulse signal pass through, so that the DC working points of the front and rear stage amplification circuits do not affect each other.

5. Tuning capacitance

It is connected at both ends of the oscillation coil of the resonance circuit to select the oscillation frequency.

6. Pad capacitance

The auxiliary capacitance in series with the main capacitance of the resonance circuit can be adjusted to reduce the frequency range of the oscillating signal and significantly increase the frequency of the low frequency terminal. If the capacity of the pad capacitor is selected properly, the low frequency curve can be raised up, which is close to the ideal frequency tracking curve.

7. Compensation capacitance

It is an auxiliary capacitor connected in parallel with the main capacitor of the resonant circuit. Adjusting the capacitor can enlarge the frequency range of the oscillating signal.

8. Neutralization capacitance

It is connected between the base and emitter of the triode amplifier to form a negative feedback network to suppress the self-excited oscillation caused by the capacitance between the triode poles.

9. Frequency stabilizing capacitor

In the oscillation circuit, it can stabilize the oscillation frequency.

10. Timing capacitance

In RC time constant circuit, it is connected in series with resistance R to determine the capacitance of charge and discharge time.

11. Acceleration capacitance

Connected to the feedback circuit of the oscillator, the positive feedback process is accelerated and the amplitude of the oscillation signal is increased.

12. Shorten capacitance

In UHF high frequency head circuit, the capacitance connected in series to shorten the length of oscillation inductor.

13. Clapper capacitance

In the capacitance three-point oscillation circuit, the capacitance in series with the inductance oscillation coil can eliminate the influence of the transistor junction capacitance on the frequency stability.

14. Scylla capacitor

In the capacitance three-point oscillation circuit, the capacitance in parallel with both ends of the inductance oscillation coil can eliminate the influence of the transistor junction capacitance and make the oscillator easy to vibrate at the high frequency end.

15. Amplitude stabilizing capacitance

In the frequency discriminator, it is used to stabilize the amplitude of the output signal.

16. Pre weighted capacitance

In order to avoid the attenuation and loss of the frequency division caused by the audio modulation signal in the process of processing, the RC high frequency component is set to enhance the network capacitance.

17. De weighting capacitance

In order to recover the original audio signal, it is required to attenuate the high frequency component and noise raised by pre weighting in the audio signal together, and set the capacitance in the RC network.

18. Phase shifting capacitance

Capacitance used to change the phase of an AC signal.

19. Feedback capacitance

It is connected between the input and output of the amplifier to make the output signal return to the capacitance of the input.

20. Step down current limiting capacitance

In series connection in the AC circuit, the capacitive reactance characteristic of the capacitance to the AC is used to limit the current of the AC, so as to form the voltage dividing circuit.

21. Reverse capacitance

It is used in line scan output circuit and connected between collector and emitter of line output tube to generate high voltage line scan sawtooth wave reverse path pulse. Its withstand voltage is generally above 1500V.

22. Correction capacitance

It is connected in series in the deflection coil circuit to correct the extended linear distortion of the picture tube edge.

23. Bootstrap boost capacitor

The potential of a certain point in the circuit is raised by using the charging and discharging energy storage characteristics of the capacitor, so that the potential of this point can reach 2 times of the voltage value of the power supply end.

24. Dimming capacitor

The capacitor is arranged in the video amplifier circuit to eliminate the residual bright spot on the picture tube when the power is turned off.

25. Soft start capacitance

Generally, it is connected to the base of the switch tube of the switching power supply to prevent the excessive surge current or high peak voltage from being added to the base of the switch tube when the power supply is turned on, resulting in the damage of the switch tube.