The filter capacitor withstand voltage and capacity of the power amplifier are not as large as possi

The withstand voltage and capacity of the filter capacitor of the power amplifier are not as large as possible, and the overall balance and collocation are more important, as long as it is enough.

The function of the capacitor is filtering and energy storage, we all know that the rectifier diode is not always on, and the power amplifier needs a steady stream of current most of the discharge current is supplied by the discharge current of the capacitor, so the quality of the capacitor should not be underestimated, and when the capacity is too large, its instantaneous charging current has a great impact on the bridge stack, and will cause the sound quality to be too "dull", not lively enough, no sense of life, that is, the transient response is not ideal, and the problem of "blunt" caused by the single large-capacity capacitor should be used, some manufacturers use many small-capacity capacitors in parallel. to get the required capacity, but the cost increases. If the electrical characteristics of the parallel small-capacitance capacitors are too far apart, the sound quality is not as good as that of the individual capacitors.

There is no need to pursue too high withstand voltage for capacitors, just meet the design withstand voltage requirements, too high withstand voltage will only cause an increase in volume and cost, and will not help its application.

Increase the filter capacitance while taking into account the transient response, that is, small capacitors can be connected in parallel on a large capacitor. A small capacitor of a few hundred microfarnets and a few tenths of a microfarf can be paralleled at the same time. In addition, the original design of the withstand voltage value is 35 volts, which means that the power supply voltage of the circuit is below 35 volts, and the withstand voltage value of the new capacitor replaced is above 35 volts.

Moreover, the filter capacitance capacity of the power amplifier is not necessarily good as the larger, and it is meaningless outside a certain range.

The above is a personal opinion, I hope it can solve your doubts.

Replacing 35v1000uf with 63v10000uf is too fine. **The power supply needs to have enough energy when there is explosive power in an instant**, and the large capacitor can come in handy at this time. The reason why manufacturers don't use it is because of the cost factor; However, larger filter capacitors are not always better, and excessive capacitance will increase the burden on power transformers and rectifier diodes.

Be. Theoretically, the larger the capacitor for power supply filtering, the better, generally large capacitors filter low-frequency waves, and small capacitors filter high-frequency waves. Capacitor to ground filtering requires a smaller capacitor to be connected to ground in parallel, providing a ground path for high-frequency signals, and the capacitor to the ground should be as close to the ground as possible in power supply filtering.

After passing through the rectifier bridge, it is pulsating DC, and the fluctuation range is very large. As we all know, the voltage at both ends of the capacitor can not be abruptly changed, so the output can be smoothed, and the small capacitor is used to filter out high-frequency interference, so that the output voltage is pure, the smaller the capacitance, the higher the resonant frequency, and the higher the interference frequency that can be filtered.

If the power amplifier power supply filters the capacitor.

If the capacity is small, the power supply outputs direct current.

Not pure enough (the ripple coefficient is large), the speaker will hear an obvious "buzzing" sound, and at the same time, when the volume is loud and dynamic, it will obviously feel that the stamina is insufficient, the strength of the bass is not enough, and the explosive power of the amplifier is insufficient.

Appropriately increasing the filter capacitor will improve the above situation.

The filter capacitor is used for filtering in the power supply part of the power amplifier, and increasing the filter capacitor can reduce the ripple of the power supply, reduce the noise and improve the output sound quality.

Of course, the larger the filter capacitor of the amplifier preamplifier, the better, so that the power supply is closer to direct current. Of course, you still need to consider the location.

The size of the filter capacitor of the power amplifier power supply, the filter capacitor and the load resistance form the RC constant, the time t is the lowest frequency of the audio 20Hz, t=25ms, rc=2t or more.

The power consumption of the power amplifier is not continuous, and the power supplied is 1 3 of the maximum power is enough. Another way to reduce AC internal resistance is to increase the filtering, capacitance and load impedance and the lowest frequency cycle, preferably 5 cycles.

The total power consumption of the power amplifier is composed of two parts: the output power of the power amplifier and the heat loss power generated during the output process of the power amplifier. According to the law of conservation of energy, it can be known that the total power consumption of the power amplifier = the output power of the power amplifier + the heat loss power of the power amplifier.

The size of the filter capacitor of the power amplifier power supply, I think, the filter capacitor and the load resistance form an RC constant, the time t is the lowest frequency of the audio 20Hz, t=25ms, rc=2t or more.

AC220V is the AC9V after transformer voltage conversion. Full-wave rectification is adopted, and the DC peak is 2 9 1 41 times, which is about 25 38V. Theoretically, the withstand voltage of the filter capacitor is not less than 25 38V.

With bridge rectification, the DC peak is 9 1 41 times, which is about 12 69V. Theoretically, the withstand voltage of the filter capacitor should not be less than 12 69V, and the withstand voltage of 16V can be used. After passing through the 7805 capacitor, the withstand voltage of the capacitor is greater than 5V.

The energy storage device is connected in parallel at the output end of the rectifier power circuit to reduce the ripple coefficient of AC and smooth the output of DC. In the electronic circuit that converts the AC power supply into the DC power supply, the filter capacitor not only makes the DC output of the power supply smooth and stable, but also reduces the influence of the AC pulse current on the electronic circuit.

At the same time, in the working process of the electronic circuit, the fluctuation and interference of the current are absorbed by the AC power supply, so that the working performance of the electronic circuit is more stable.

AC220V is AC9V after transformer voltage transformation, if the full-wave rectification is used, its DC peak value is about 2*9*times, theoretically the filter capacitor withstand voltage is not less, considering AC220V, under normal circumstances between 198 242V changes, the filter capacitor usually chooses the withstand voltage 32V.

If the bridge rectification is adopted, the DC peak value is about 9*times, and the withstand voltage of the filter capacitor is not less than the withstand voltage in theory, and the withstand voltage of 16V can be selected. The capacitor withstand voltage after 7805 is greater than 5V.

It is an energy storage device that is connected in parallel at the output end of the rectifier power supply circuit to reduce the AC ripple coefficient and smooth the DC output. In the use of electronic circuits that convert AC to DC power, the filter capacitor not only smooths and stabilizes the DC output of the power supply, but also reduces the influence of the alternating ripple current on the electronic circuit.

At the same time, it can also absorb the current fluctuation generated during the operation of the electronic circuit and the interference connected by the AC power supply, so that the working performance of the electronic circuit is more stable.

The withstand voltage value of the filter capacitor is based on the highest voltage that may occur in the circuit, and the withstand voltage value must be higher than the maximum voltage possible.

Different types of filters with different structures have different methods for calculating the capacity of filter capacitors.

Take a first-order RC low-pass or high-pass filter as an example, with a cut-off frequency of f=1 (2 rc).

The product of rc can be calculated based on the cut-off frequency.

Since the specifications of the capacitor are relatively small, it is generally based on experience to select the capacitance value of the appropriate capacitance, and then calculate the resistance value, if the resistance value is not suitable, change the capacitance value and then calculate the resistance value.

The so-called appropriate capacity is generally based on the principle that it is easy to obtain at hand.

In addition, for low-pass filters, if the load input impedance behind the filter is large enough (such as a voltage follower composed of op amps, inverting proportional amplifiers, instrument differential amplifiers, etc.). The choice of filter capacitor can be arbitrary; If the load input impedance behind the filter is smaller, the capacitance should be slightly larger, so that the output impedance of the filter is smaller and less affected by the load.

The minimum capacitance is generally not less than 100pf. This is because if the filter capacitance is too small, the influence of the distributed capacitance cannot be ignored, and it is difficult to obtain an accurate cut-off frequency.

For non-polar capacitors, the general capacitance should be less than 1uf, because capacitors above 1uf are not easy to procure and the cost is high.

For high-pass filters, the capacitance is inversely related to the load.

For the normal use of this filter capacitor, the filter capacitance value and withstand voltage value must be matched according to the design and requirements of the circuit, otherwise it will cause unnecessary losses.

As long as the voltage of the filter capacitor is greater than 50% of the connected voltage, there is no formula for the capacity, generally according to the use of the post-amp or the size of the current, if the single voltage is stabilized, 7805 is 5V voltage stabilization, choose 1000up or less, if the current fluctuation of the post-amp is large, you can choose large capacity, such as power amplifier and the like, the bigger the better.

It depends on your use requirements, some power supplies require high output DC performance, then you need to have a larger filter capacitor, if it is an ordinary device, then 1500 to 2000uf per amperere output is enough. For example, if you output 9V AC, then you should choose a capacitor with a withstand voltage greater than 12V.

Capacitance Capacitance 4700uf withstand voltage 》9* and a 104 ceramic capacitor.

The filter capacitor capacity that needs to be connected after 7805 = 200uf

In terms of voltage, it is generally at least 2 times higher than the voltage, because the power supply will have a peak voltage peak of more than 12V or even to 20V. Therefore, the larger the choice, the safer it is not easy to explode, and generally 35V is better, and no matter how high it is, it does not make much sense.

In the case of filtering, the larger the filter, the smoother the voltage, the better. However, if the capacitance is very large, the capacitance is quite short circuit at the moment when the power supply is turned on, and the impact will be great. Generally 1000uf is big enough.

35V 470 or 35V 1000UF micromethod is recommended. Because the voltage of the power supply will be relatively high when there is no load, it may reach 17V or even higher.

Hello, it is a pleasure to serve you and give you the following answer: Nichicon is a Japanese manufacturer of capacitors, its capacitors have good withstand voltage performance, can provide higher voltage and current, thus improving the efficiency of power amplifiers. :p Anasonic is a Japanese capacitor manufacturer, its capacitors have good withstand voltage performance, which can provide higher voltage and current, thereby improving the efficiency of power amplifiers.

In addition, it has good anti-vibration performance, which can effectively reduce noise. : Rubycon is a Japanese manufacturer of capacitors, its capacitors have good withstand voltage performance, can provide higher voltage and current, thus improving the efficiency of power amplifiers. In addition, it has good vibration resistance, which can effectively reduce noise, and has good heat resistance, which can improve the reliability of the power amplifier.

To solve the problem of different brands of power amplifier power filter capacitors, we must first determine our own needs and choose the appropriate capacitor brand according to our own needs. For example, if you need high voltages and currents, you can choose Nichicon; If vibration resistance is required, Panasonic can be selected; If heat resistance is required, RubyCon is an option. Personal Tips:

When choosing the filter capacitor of the power amplifier power supply, it is necessary to choose the appropriate brand according to your own needs to ensure the reliability and efficiency of the power amplifier power supply.