Can anyone introduce the knowledge of capacitor filtering?

The capacitance parallel connection is large and small, which is caused by the non-capacitive characteristics of the capacitor. Aluminum electrolytic capacitors are generally seen in large capacitors, and they are composed of a coiled structure, so they introduce a lot of inductance, and together with other characteristics, they lead to unfavorable situations such as a sharp decrease in capacitance and a sharp increase in capacitance loss in high-frequency situations. Small capacitors are much better at filtering high frequencies, so the combination of them will greatly improve the quality and reliability of the power supply.

Clutter is relative to regular waveforms, and glitches are waveforms that occur instantaneously. Generally, the frequency is relatively high, especially the spectrum generated is wide, and it is relatively difficult to filter out these.

Ceramic capacitors filter high frequencies, electrolytic capacitors filter low frequencies.

The filter circuit uses the difference in the impedance of the reactive components to AC and DC to achieve filtering. Capacitor C is open to DC and has little impedance to AC, so C should be connected in parallel at both ends of the load. The inductor L has a small impedance to DC and a large impedance to AC, so L should be connected in series with the load.

After filtering the circuit wave, the DC component can be retained, and a part of the AC component can be filtered out, the proportion of AC and DC components is changed, the ripple coefficient of the circuit is reduced, and the quality of DC voltage is improved.

Interesting, contact me and I'll give you the answer!

The above bosses have been very detailed, and I will also add a point (when using electrolytic capacitors, you must pay attention to the polarity, and when disassembling the filter capacitor with high working voltage, you must short-circuit his feet for discharge)...

The slower the capacitor discharges, the smoother the output voltage and the better the filtering. The speed of capacitor discharge is related to the capacitance c of the capacitor and the load r, the larger c and r, the slower the capacitor discharge. Therefore, the larger the capacitance c of the capacitor, the slower the discharge, and the better the filtering effect.

At the same time, the capacitance of the filter capacitor selected in the filter circuit is relatively large, the most commonly used is hundreds to thousands of microfarnese electrolytic capacitors, and tantalum capacitors or niobium capacitors are also used in high-demand occasions. However, in the case of tens of kilohertz or even higher frequencies, the requirements for frequency characteristics are much more important than the requirements for capacity.

The principle of capacitive filtering is easily understood and introduced as follows:

Filtering is achieved by using the capacitor to achieve a small equivalent capacitive reactance to a specific frequency, which is similar to a short-circuit endurance.

Capacitors are characterized by their extremely high impedance to direct current, which is equivalent to a no-pass. For alternating current, the higher the frequency, the smaller the impedance. Using this feature of the capacitor, we can filter out the non-AC components of the stove mixed with the direct current, so it is called "filtering".

Why can capacitors be filtered?

Electric sound、Simply put, it can be charged and discharged。 That is, when the external voltage is higher than its existing "inventory" voltage, it will charge and receive the "goods", and when the "inventory" is higher than the external voltage, it will release the "goods". The "say" in "goose potential" must be the voltage fluctuating, otherwise it is not called "wave", since there are ups and downs.

It's like on the electric inspection.

It will be higher than the voltage of the capacitor "goods", and it will be "good" for a while. When the root is high, it will be absorbed, and when it is low, the capacitance will be released. As a result, the "wave" will pass through the capacitor and the fluctuations of the "wave" will be weakened.

It plays the role of filtering and completes the mission of filtering.

Filter capacitor features:

The temperature rise is low. The circuit of the multi-wave filter is composed of a series reactor of the capacitor, which forms the lowest impedance at a certain harmonic order to absorb a large number of harmonic currents, and the quality of the capacitor will affect the stable absorption effect of the harmonic filter.

Low attrition. dielectric loss tangent (tgδ); 0. 00。

Convenience. Small size and light weight, extremely easy to handle and install.

Hello, capacitor filter circuit is a common power filter circuit, which can filter the power supply signal through the characteristics of the capacitor. Specifically, the capacitor filter circuit passes the power signal through a capacitor, so that the capacitor can short-circuit the high-frequency signal, so as to achieve the purpose of filtering. At both ends of the capacitor, the load circuit can be connected to achieve a stable power supply to the load circuit.

The filtering effect of the capacitor filter circuit depends on the capacitance of the capacitor, and the larger the capacitance, the better the filtering effect. At the same time, the capacitor filter circuit can further improve the filtering effect by connecting multiple capacitors in series. It should be noted that the filtering effect of the capacitive filter circuit for low-frequency signals is not ideal, so in practical applications, Shoulingchun may need to combine with other filter circuits to achieve comprehensive filtering.

In addition to capacitive filter circuits, there are many other types of filter circuits, such as inductance filter circuits, RC filter circuits, etc. Each filter circuit has its own applicable scenarios and characteristics, which need to be selected according to the specific situation. Hope mine can help you.

Summary. Hello dear <>

Capacitor filter circuit is a commonly used signal filter circuit that uses the characteristics of capacitors to filter signals. Specifically, a capacitor filter is a filter that uses the impedance of the capacitor to change the impedance of the signal at different frequencies by inputting a signal into a capacitor. In a capacitive filtering circuit, an impedance is presented between the two plates of a capacitor that varies with the frequency of the signal.

When the input signal frequency is low, the impedance of the capacitor is larger, which can filter out the low-frequency signal; Whereas, when the frequency of the input signal is higher, the impedance of the capacitor is smaller, and the high-frequency signal can pass through. Therefore, by reasonably designing the capacitance value, the filtering of signals of different frequencies can be realized within a certain range. The basic form of a capacitive filter circuit is a single-stage RC filter, which consists of a resistor and a capacitor.

After the input signal passes through the capacitor, the capacitor filters the signal at different frequencies, and the output signal is the filtered signal.

How does the capacitive filter circuit achieve filtering?

Hello dear <>

Capacitor filter circuit is a commonly used signal filter circuit, which uses the characteristics of capacitors to filter the signal. Specifically, a capacitor filter is a filter that uses the impedance of the capacitor to change the impedance of the signal at different frequencies by inputting a signal into a capacitor. In a capacitive filtering circuit, an impedance is presented between the two plates of a capacitor that varies with the frequency of the signal.

When the input signal frequency is low, the impedance of the capacitor is larger, which can filter out the low-frequency signal; When the frequency of the input implicit signal is high, the impedance of the capacitor is smaller, and the high-frequency signal can be passed. Therefore, by reasonably designing the capacitance value, the filtering of signals of different frequencies can be realized within a certain range. The basic form of a capacitive filter circuit is a single-stage RC filter, which consists of a resistor and a capacitor.

After the input signal passes through the capacitor, the capacitor filters the signal at different frequencies, and the output signal is the filtered signal.

There are other forms of capacitor filters, such as multi-stage RC filters and L-C filters, which all use the characteristics of the capacitor to filter the signal. I wish you a happy life in Pailing! I hope I will be helpful to you.