The role of capacitors in DC regulator circuits

It plays the role of filtering, because the AC after rectification is pulsating DC, and the charge-discharge effect of the capacitor is required to change the pulsating DC into a stable DC.

The function of the capacitor in the DC regulated circuit is mainly to filter out the AC, so it is also called the filter capacitor, so that the DC regulated power supply outputs a stable DC.

Filtering! Typically, a large electrolytic capacitor is added between the two endpoints of the input and output of the power supply. Stabilize the current in the circuit.

There are several capacitors, and there are anti-interference ones. There is also the filtering effect on the first floor.

Let's start with my point: it's equivalent to opening the way.

The reason why I think this is because capacitors have the characteristics of on-AC resistance and DC.

Why? This is due to the fact that capacitive conduction is carried out through charge and discharge cycles, not actually through the capacitor.

Alternating current is a current that is constantly changing in size and direction, and when the forward current charges the capacitor, the reverse current capacitor discharges it, and there is a continuous current in the line, as if the electricity is flowing cautiously"Passed"capacitance.

Direct current, on the other hand, is a current that does not change in size or direction, so it cannot form a charge-discharge cycle at the poles of the capacitor"Passed"capacitive.

So, in my opinion, no matter what other people think, I insist that this is the way it was revealed.

The calculation formula is as follows:

The resistance of the capacitor in the AC circuit is called the capacitive reactance mode, which is called XC, and the calculation formula is XC=1 (C)=1 (2 FC), F is the frequency, the unit is Hz, =2 F is the angular frequency, and the single-answer endurance is 1 s. It can be seen that when =2 f=0, the capacitance anti-modulus xc is infinite, so the capacitance is quite open in the DC circuit.

A capacitor is the equivalent of an open circuit in a DC circuit.

Direct current. When the capacitor is connected, it plays the role of bypass, decoupling, filtering and energy storage.

1. The bypass capacitor is an energy storage device that provides energy for the local device, which can make the voltage regulator.

The output is homogenized and the load demand is reduced. It's like a small rechargeable battery.

Similarly, the bypass capacitor can be charged and discharged to the device.

2. Remove lotus root, also known as lotus root. In terms of circuits, it is always possible to distinguish between the source of the drive and the load being driven. If the load capacitance is relatively large, the driving circuit should charge and discharge the capacitor in order to complete the signal jump, and when the rising edge is relatively steep, the current is relatively large, so that the driving current will absorb a large power supply current.

3. The function of the capacitor is to pass high resistance and low resistance, and pass high frequency resistance and low frequency. The larger the capacitance, the easier it is for low frequencies to pass through, and the larger the capacitance, the easier it for high frequencies to pass through. Specifically, it is used in filtering, with large capacitors filtering low frequencies and small capacitors filtering high frequencies.

4. The energy storage capacitor passes through the rectifier.

The charge is collected and the stored energy is transferred to the output of the power supply via the converter leads.

The function of the five capacitors is to stabilize the filter, the four resistors are the current limiting and divider, and the resistance value is based on the voltage and current required by the radio, which can be known by Ohm's law.

The role of the capacitor here is to filter, and the resistance value is calculated based on the impedance and voltage rating of the radio.

Capacitors are paralleled in order to increase capacitance. resistors in parallel; It is to reduce the resistance value and increase the power.

In buck step-down circuits, the inductor plays the role of step-down and energy storage. Capacitors are used for energy storage and smooth voltage.

Without inductance, the circuit cannot act as a step-down. Without capacitors, the circuit cannot smooth the voltage.

buck circuit.

The inductor is generally selected according to the allowable current ripple value, and whether the current works continuously and intermittently should be considered. The capacitance is selected according to the allowable voltage ripple value at both terminals. The higher the switching frequency, the smaller the inductance, the smaller the voltage ripple, and the smaller the capacitance.

Equivalent circuit models and basic laws.

1) As can be seen from the circuit, the inductor L and the capacitor C form a low-pass filter.

The principle of this filter design is to allow the DC component of US(T) to pass through, and to suppress the harmonic component of US(T). The output voltage uo(t) on the capacitor is defeated, and the dc component of us(t) is then raised and the reed adds a small ripple.

uripple(t)。

2) The working frequency of the circuit is very high, and the ripple uripple(t) caused by the charge and discharge of the capacitor in a switching cycle is very small, and the voltage on the capacitor can be regarded as constant macroscopically relative to the DC voltage output on the capacitor. When the circuit works in steady state, the voltage on the output capacitor is composed of a small ripple and a large DC component, which can be regarded as a constant DC on a macro scale, which is the principle of small ripple approximation in the steady-state analysis of switching circuits.

3) When the charging charge of the capacitor is higher than the discharge charge in a cycle, the capacitor voltage increases, resulting in the decrease of the charging charge and the increase of the discharge charge in the subsequent cycles, so that the rise rate of the capacitor voltage slows down, and the continuation of this process is until the charge-discharge balance is reached, and the voltage remains unchanged at this time.

The inductor makes the current not abrupt, and the capacitance makes the voltage not abrupt.

The capacitor is an energy storage element (electric field electric field energy after charging), and the capacitor needs a certain time to charge and discharge, and the voltage at both ends cannot be abruptly changed. When it is connected in parallel to a pulsating DC circuit, it is charged when the voltage is higher than the capacitor voltage, and it discharges when it is lower than the capacitor voltage, so that the voltage on the circuit is smoother and more stable than the input.

In AC circuits, because the direction of the current changes with time as a function of a certain relationship. The process of charging and discharging capacitors has time, and at this time, a changing electric field is formed between the plates, and this electric field is also a function of time. In fact, an electric current is passed between the capacitors in the form of an electric field.

When a capacitor is placed on the power input of the circuit board and connected in parallel with the power supply equipment, because the impedance of this bypass capacitor is much smaller than the inductance on the distribution line, the sudden current flows from the bypass capacitor and no longer flows through the power distribution line, so that there is no voltage generation on the inductance on the power distribution line.

The bypass capacitor reduces the variation of the current on the power supply distribution line, smoothing the supply current on the power supply distribution line to a continuous average current.

It can be considered that the low impedance of the bypass capacitors connected in parallel shorts the high-impedance power supply equipment channel (power supply equipment + power distribution line) at the time of high-speed current switching, providing the required fast-changing current to the circuit system. The power supply device maintains the required current for steady state and slow changes, and continuously replenishes the charge to the bypass capacitors. However, this does not cause a high-speed current change in the power supply equipment and the current distribution line.

The setting of the bypass capacitor reduces the high-speed current change on the power supply, and the induced voltage of the inductor on the power supply distribution line is correspondingly reduced, or the voltage noise on the power supply is reduced, and the voltage is regulated.

The capacitor is generally thought to be able to pass through the AC channel, but when the voltage of the regulated voltage changes, it is considered that there is an AC part of the voltage, and the capacitor will filter out the voltage of the AC part, leaving only the DC regulated part.

Summary. Hello dear, glad to answer for you, <>

The role of the capacitor in the DC regulated power supply: the energy storage device that provides energy for the local device, it can make the output of the voltage regulator uniform, reduce the load demand, and the supercapacitor is more green than the traditional one, because it is the dielectric formed by the current, and the interface double layer formed by the dielectric cycle and the electrode is stored in the whole process, thank you for your consultation, I hope this service can help you, you can click on my avatar to follow me, If you have any questions in the future, you can consult me again. I wish you a happy life, a happy family, good health, and all the best <>

What is the role of capacitors in DC regulated power supplies?

Hello dear, glad to answer for you, <>

Dear, the role of the capacitor in the DC regulated power supply: the energy storage device that provides energy for the local device, it can make the output of the voltage regulator uniform, reduce the load demand, and the supercapacitor is more green than the traditional one, because it is formed by the current to form the dielectric, through the circulation of the dielectric and the interface double layer formed by the electrode to store the capacity, the whole brother orange thick process, there will be no chemical reaction Thank you for your consultation, I hope this service can help you, you can click on my avatar to follow me, Later, Wu Yan continued to have questions, so it was convenient to consult me again. I wish you a happy life, a happy family, good health, and all the best <>

What is the RB resistance in the basic amplification circuit, the RC resistance is better.

Kiss, RC is the load resistance, and RB is the bias current resistance of the triode base B.

DC regulated power supplies generally use low-frequency electrolytic capacitors. The reason is that the DC regulated power supply needs to provide a stable DC voltage output, and the electrolytic capacitor has a high capacitance, low ESR (Royal Bucket Equivalent Series Resistance), and a low natural frequency, which can provide a better filtering effect, thereby reducing the ripple and noise of the output voltage. In addition, electrolytic capacitors are relatively inexpensive and relatively easy to obtain.

High-frequency capacitors are mainly used in high-frequency circuits, such as switching power supplies, signal transmission lines, etc. High-frequency capacitors have the advantages of small size, high natural frequency, and fast frequency response, and can provide good high-frequency performance. However, the capacitance of high-frequency capacitor ballast trousers is smaller, and the ESR is larger, so it is not suitable for use in DC regulated power supplies.

Therefore, in general, DC regulated power supplies use low-frequency electrolytic capacitors, while high-frequency capacitors are mainly used in high-frequency circuits. Of course, in some special applications, it may also be necessary to use both high-frequency and low-frequency electrolytic capacitors to meet different circuit requirements.