On the issue of resistors and capacitors being connected in series and parallel

Since it is a current-limiting resistor, of course, it is connected in series with a capacitor. Parallel to the capacitor is a 5mA light-emitting diode as an indicator, and the resistance value of this resistor is about 90k ohms. Charging a 450V 220UF capacitor is dangerous, so please be sure to pay attention to safety.

Before wiring, the capacitor must be safely discharged.

The current limiting resistor should be connected in series with the capacitor!

Capacitor in parallel with 1 x 5mA LED as an indicator! If the voltage at both ends of the capacitor is 450 volts! Then the series resistance is calculated as follows!

450 volts = volts. r=u i r=oh. (89 thousand euros).p=ui=100 kOhm 3 Watt metal film resistor in series!

1) Since it is a "current limiting resistor", it should be connected in series in the trunk circuit.

2) Since it is a "1 x 5mA" light-emitting diode connected in parallel with the capacitor [as an indicator], if the DC voltage (constant voltage) of the charging is 450V, the resistance r=u i=450V in series with the light-emitting diode 5mA=90kohm.

The current-limiting resistor has to be connected in series, and the current-limiting resistor of the light-emitting diode can't be calculated, because you don't have a full charge voltage on a given capacitor.

The function of a capacitor connected in parallel on the resistor is: for electronic circuits: it is to reduce the impedance of high-frequency signals, which is equivalent to differentiation, so that the signal rise speed is accelerated, which is used to improve the response speed; For power circuits:

Regardless of whether RC is connected in series or parallel, the role of the capacitor is to prevent sudden changes in voltage.

Capacitance, also known as capacitance, refers to the amount of charge stored at a given potential difference, denoted as c, and the SI unit is farad (f). Capacitors are divided into electrolytic capacitors, solid capacitors, etc.

Generally speaking, the charge will be forced to move in the electric field, when there is a medium between the conductors, it hinders the movement of the charge and makes the charge accumulate on the conductor, resulting in the accumulation and storage of charge, and the amount of stored charge is called capacitance.

Practical Applications of Capacitors:

In electronic circuits, capacitors are used to block direct current through alternating current, and are also used to store and release electrical charges to act as filters to smooth out pulsating signals. Small-capacitance capacitors, usually used in high-frequency circuits, such as receivers.

Large-capacitance capacitors are often used for filtering and storing charges, and there is another feature, generally the capacitors on the 1 F or more are electrolytic capacitors, and the capacitors below 1 F are mostly porcelain capacitors.

An electrolytic capacitor has an aluminum shell that is filled with an electrolyte and leads out two electrodes, which act as positive and negative electrodes, unlike other capacitors, which cannot be mismatched in the circuit, while other capacitors have no polarity. <>

Just change the part of the RL series to RC in parallel.

A series RL circuit can be equivalent to a parallel RC circuit with the same resonant frequency.

Numerically, the resonant frequency of the RL circuit can be calculated first, and then the RC circuit can be designed according to this frequency.

For the impedance of the inductor there is zl = jwl and the impedance of the capacitor zc = 1 jwc = - j wc. The impedance of the complex form can be brought in, and the calculation method of series and parallel connection is the same as that of pure resistance.

The series connection between the inductor and the resistance is not equivalent to the parallel connection between the resistance and the capacitor, but only the parallel connection between the resistance and the inductor version. Let's take a look at the admittance after the weight resistance string inductance:

y=1 (a+jb)=(a-jb) (a*a+b*b)=a (a*a+b*b)-jb (a*a+b*b)=g+jb, admittance can be regarded as two parts in parallel, replaced by impedance representation, r=1 g=(a*a+b*b) a, jx=1 jb=-j b=-j[-(a*a+b*b) b]=j(a*a+b*b) b. In the physical sense, the resistive series inductance is inductive, and in order to be equivalent, it should still be inductive after transformation, so it cannot be a parallel capacitance.

For a passive one-port network that contains capacitors, inductors, and resistive elements, the ports may be capacitive, inductive, and resistive, and when the voltage U and current I of the circuit port are in phase, and the circuit is resistive. It is called the phenomenon of resonance, and such a circuit is called a resonant circuit.

The essence of resonance is that the electric field energy in the capacitor and the magnetic field energy in the inductor are converted to each other, increasing and decreasing, and completely compensating. The sum of the electric and magnetic field energy remains the same at all times, and the power supply does not have to convert energy back and forth with the capacitor or inductor, but only needs to supply the electrical energy consumed by the resistance in the circuit.

1. Parallel circuit of the capacitor After the capacitor is connected in parallel, the area of the metal plate is equivalent to the total area of each parallel capacitor.

Therefore, when multiple capacitors are connected in parallel, their total capacitance is the sum of the capacitances of each parallel capacitance.

i.e.: c=cl+c2+c3+....+cn When two capacitors are connected in parallel, the loss resistance r of the whole capacitor is the parallel value of the loss resistance r of the two capacitors, and the actual value of the loss resistance r will be very small, so that the loss of the combined capacitor in the high-frequency circuit is very small.

2. The series circuit of the capacitor In some special cases, the capacitor can also be used in series.

When capacitors are used in series, the distance between the metal plates is equal to the sum of the series capacitors (the total capacitance of the capacitors will be less than any one of the capacitances in the series circuit).

Therefore, when a capacitor is connected in series, the reciprocal of the series capacitance is the reciprocal sum of each capacitance.

That is: 1 c=1 ci+l c2+1 c3+....When the +L CN capacitors are connected in series, they will have a voltage divider effect, and their voltage partial ratio is the reciprocal ratio of the capacitance.

When the two capacitors are in series, the loss resistance of the two capacitors is also in the series state, which will make the equivalent loss resistance of the whole capacitor larger, so that the loss value becomes large.

1) The formula for series-parallel connection of resistors is the same.

2) Series connection: The sum of the reciprocals of each sub-capacitance is equal to the reciprocal of the total capacitance 1 c1 + 1 c2 + 1 c3....1 c total.

3) Parallel: The sum of the subcapacitance is equal to the total capacitance C1+C2+C3....c Total.

In the first figure, the two points are connected in parallel in the circuit called the parallel resistor, and the circuit composed of a simple parallel resistor or electrical appliances (such as a television, a bridge air conditioner, a computer, etc.) is called a parallel circuit. Compared with the second disadvantaged circuit, the resistors (electrical appliances) are connected in series in turn.

I'm going to talk to you about this in layman's terms. 1. The current flows through the resistor, and some interference clutter with a relatively high frequency will be generated at both ends of the resistance (for example: a river with water and burning flowing rapidly, there are many raised stones in the middle of the river, and the water hitting the stones produces a lot of waves, the water is like an electric current, and the stones are like resistance, and the waves generated are some interference clutter. In order to filter out these interference clutter, it is necessary to connect a capacitor in parallel at both ends of the resistor (the capacitor C60 and the resistor R9 above), because the clutter frequency of the interference generated is relatively high, so the capacitance value of the selected capacitor is generally very small. 2. The following resistor (R56) and capacitance (C63) play a role in expanding the passband. We can think of it in an extreme way, if the input voltage is DC, since the capacitor is equivalent to an open circuit relative to DC, the input voltage is added to the input of the op amp through the partial voltage of the resistor (R56) and the resistance (R15).

If the input voltage is a high-frequency voltage, which is equivalent to a short circuit for the capacitor, the input voltage is directly added to the input of the op amp through the coupling of the capacitor without attenuation. Generally speaking, for the input signal, the higher the frequency, the smaller the attenuation, and the lower the frequency, the greater the attenuation. If you still don't know anything and other questions, you can ask me.

The capacitor series capacity becomes smaller, and the capacity becomes larger when connected in parallel;

The series resistance of the resistor becomes larger, and the parallel resistance becomes smaller.

Resistors are generally called resistors in daily life. It is a current limiting element, after the resistor is connected to the circuit, the resistance value of the resistor is fixed, generally two pins, which can limit the current through the branch it is connected to. If the resistance value cannot be changed, it is called a fixed resistor.

Those with variable resistance are called potentiometers or variable resistors.

Capacitors, often referred to as capacitors, are denoted by the letter C. Definition 1: A capacitor, as the name suggests, is a 'container for electricity' and is a device that holds an electric charge.

Product Name: capacitor. Capacitors are one of the electronic components widely used in electronic devices, which are widely used in circuits in terms of DC blocking, coupling, bypass, filtering, tuning loop, energy conversion, control, etc.

The larger the capacitance, the lower the frequency of passing; Conversely, the smaller the capacitance, the higher the frequency of passage. The capacitor is on the high frequency resistance and low frequency, and the inductor is on the low frequency resistance and high frequency. Theoretically (i.e., assuming the capacitor is pure capacitance), the larger the capacitance, the smaller the impedance, and the higher the frequency of passage.

However, in fact, most of the capacitors over 1 micromethod are electrolytic capacitors, which have a large inductance component, so the impedance will increase when the frequency is high. Therefore, ceramic capacitors commonly used in engineering to microfa are used for coupling or bypass capacitors in high-frequency circuits. Sometimes you will see a large capacitance electrolytic capacitor connected to a small capacitor in parallel, then the large capacitor passes on the low frequency and the small capacitor passes on the high frequency.

For high-frequency components, large capacitors do not work, because the capacitor itself has inductance, for high-frequency components, the large capacitance has degenerated into an inductance, and then the small capacitance comes into play, (we can get it according to the impedance formula). For low-frequency components, we need a large capacitance to stabilize the fluctuating voltage, so small capacitors play a negligible role. The combination of large and small capacitors combines the best of both worlds.

If it is alternating current, in the circuit analysis, the principle of the low-pass filter and the high-pass filter is the same, if the signal and the capacitor are connected in series, it is the high-pass filter, and the low frequency is filtered out, so if the capacitance increases, the signal with a lower frequency can also pass; Conversely, if the signal and capacitor are connected in parallel, it is a low-pass filter that filters out the high frequencies, and if the capacitance is reduced, the frequency can be passed through a little higher. Keeping in mind a few key concepts, these are the basic principles of circuit analysis, will be helpful to you. If you want to understand the essence thoroughly, I'm afraid few people can really explain it.

The series-parallel connection of capacitors is just the opposite of the series-parallel connection of resistors, such as series 1 c total = 1 c1 + 1 c2 +.1 CN, parallel c total = C1 + C2 + .cn.

Capacitor series connection can filter low frequency capacity to become smaller, parallel connection to become larger, can only say that there is such a trend, the specific filter depends on the size of the capacity.

The total capacitance of the capacitor series becomes smaller, so the impedance to the low-frequency signal is larger.

The total capacitance of the capacitor in parallel becomes larger, so the impedance to the high-frequency signal is smaller.

The capacitor series capacitance becomes smaller, showing greater capacitive reactance for low-frequency signals, while the capacitive reactance is small for high-frequency signals. At the same time, because the capacitor (especially the large capacitance) is rolled with aluminum foil, there will be a large additional inductance, and a small capacitor is connected in parallel to provide a high-frequency path (the capacitance of the small capacitor to the low-frequency signal is larger), so the high-frequency signal will be filtered out.

Filtering has little to do with series and parallel! It's all about capacity. Of course, the capacity decreases after series connection, and if you insist on filtering, you can only say that the filtering frequency has increased, and vice versa. (Contrary to what you say).

In practice, series and parallel connection are often used for the following purposes: series connection is to increase the working voltage of the capacitor or to seek special capacitance, and parallel connection is to increase the capacitance (improve the filtering effect) or reduce the internal resistance of the capacitor.

As for the high and low frequency circuits, there are many requirements for capacitors.

Parallel and series connection of resistor series.

The larger the capacitor parallel, the smaller the series of capacitors, the smaller the series, you should know why.