44
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The Intuition for RLC circuits
[!Quote] by a ConcernedCitizen
Resistors are the electrical equivalent of friction and produce losses to remove energy from the system.
If you drop a frictionless pendulum to swing it, how long does ...
- 57.3k
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What does the value of reactive power represent physically?
Let's ignore the power aspect for a second, and think about what reactance really is.
You know a math and theory, you can talk about things in abstract theoretical constructs using complex numbers, ...
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How do you determine the effective resistance of a finite grid of resistors?
The basic idea is fairly simple. You arrange a matrix (\$V\$) that represents "nodes" or vertices in your system. Each of these nodes has a scalar-valued "voltage" associated with it that can be ...
- 78.7k
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Why is a linear passive circuit stable, i.e. why does its impulse response approach zero over time?
In a circuit that is composed of only Ls, Cs and Rs ...
An input impulse will store energy in the Ls and Cs. The stored energy will be dissipated in the Rs, and will tend to zero over time.
...
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Why do I get this weird curve for impedance vs Frequency
Assuming the impedance is being calculated correctly, your problem is that you are starting at a low frequency (10 μHz) for which the impedance of your capacitor is very high (tens of megohms). The ...
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Thevenin Equivalent Voltage: why ignore the 3-kΩ resistor?
Computing a Thevenin Equivalent requires two steps:
Obtain the Thevenin Impedance \$Z_{TH}\$
Obtain the Thevenin Voltage \$V_{TH}\$
In order to compute \$Z_{TH}\$ you have to "turn off" the ...
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Why is a linear passive circuit stable, i.e. why does its impulse response approach zero over time?
I suspect the problem may arrive from the requirement of an impossible domain for passive component values. Your characteristic equation breaks down (as I'm sure you already know) into: \$\left(s+1\...
- 78.7k
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What does the value of reactive power represent physically?
When you have a complex load, its associated power can be modeled with a complex number:
$$S = P+jQ$$
Where S is the complex power, usually measured in VA, P is the real power, measured in W, and Q ...
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10
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Thevenin Equivalent Voltage: why ignore the 3-kΩ resistor?
The Thévenin voltage is also known as the "open-circuit" voltage. In this case, the open circuit is between points A and B. Because it's an open circuit, no current flows through the 3k resistor, and ...
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Source-free, under-damped, parallel RLC with 2 intial conditions
Just to be complete:
simulate this circuit – Schematic created using CircuitLab
I gather that's the circuit. And you'd like an expression for \$V_{\left(t\right)}\$ and \$I_{L\left(t\right)}\$ ...
- 78.7k
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Thevenin Equivalent Voltage: why ignore the 3-kΩ resistor?
The Thevenin voltage is when the output terminals are open-circuit so any series resistance (3K in this case) has no effect. We can also ignore the 4K resistor since it's in series with a current ...
8
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Inductor and capacitor for energy storage instead of battery
...use a LC network to store small amount of electrical energy (500 mWHr or less)
You might think that 0.5 WHr is "small" but for an LC tank, it is HUGE.
So what is 0.5 WHr?
0.5 Watt = 0.5 Joule / ...
- 81.4k
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Am I on the right path to solve this RLC-Circuit? (Need to find the voltage at the resistor)
Yes, your analysis is correct.
It would have been quicker to solve for the resistor current and then multiply through by \$\small R\$ to get the resistor voltage, \$v_R\$, as below (I've used \$\...
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Parallel RLC time domain response, with two specified initial conditions and no driving source -- it is an homogeneous system
Question Recap
I'd like to start with a quick recap taken directly from my question:
$$\begin{align*}
\frac{v_{_\text{C}}}{R_1}+C_1\frac{\text{d}}{\text{d}t}v_{_\text{C}}+\frac1{L_1}\int v_{_\text{C}}\...
- 78.7k
8
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Inductor and Capacitor Timer - Strange behaviour: Need help understanding
I'll address myself to the simulator and mathematics, shortly. They match up. That won't answer your last question about what you observed when scoping out a circuit, though. But let's say that your ...
- 13.1k
8
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Input filter LC for switching power supplies
With these types of filter I find that it's best to assume it will attenuate high-frequency noise based on a 1st order response (as if the inductor were replaced with a resistor) then, you put the ...
- 473k
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How can these passive RLC circuits change a sinusoid's frequency?
There is no loss in the system, therefore the startup transient continues oscillating forever. (Due to numerical errors in the transient simulator, it won't actually go forever.) The measurement is ...
- 45.6k
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What does the value of reactive power represent physically?
"Reactive power" is one of several possible ways of reconciling the fact that in AC systems, the voltage times the current isn't the average power.
The reason rms(V) x rms(I) is not ave(V x I) is ...
- 315k
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How to sketch the Bode diagram of the output filter of a Buck converter?
Background
Starting with your result and proceeding:
$$\begin{align*}
H\left(s\right)&=\frac{R}{R\,L\,C\,s^2+L\,s+R}\\\\
&=\frac{1}{L\,C\,s^2+\frac LR\,s+1}\\\\
&=\frac{\frac 1 {L\,C}}{s^2+...
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Am I on the right path to solve this RLC-Circuit? (Need to find the voltage at the resistor)
As you could figure out, your source is expressed as a phasor, hence we can assume safely the solution can be expressed with phasors and impedances, in consistency with the requirement of ignoring ...
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LT Spice: parallel RLC circuit resonator giving weird frequency response?
This is a likely candidate for show-stopper of the month: -
Then, when you fix that you'll realize that a voltage source (V1) is ideal and won't care a damn about C1 and L1 being present i.e. you'll ...
- 473k
7
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Input filter LC for switching power supplies
That's probably fine.
A complete analysis requires much more information (voltage range, amount of ripple and noise, surge conditions if applicable, environmental, etc.), but these data likely don't ...
- 45.6k
6
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Why is a linear passive circuit stable, i.e. why does its impulse response approach zero over time?
The simple answer is related to the Routh-Hurwitz stability criterion. This means that it simply doesn't matter how the terms of the polynomial end up as long as all the roots have negative real part. ...
- 21.8k
6
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How is this circuit providing solution of the differential equation d^2 v/dt^2 = -9v?
The output voltage v is the result of integrating twice. So whatever was before the integrating stages is d^2 v / dt^2 by definition. Since that node is driven strongly by the inverting gain stage, it ...
- 241
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How is it possible that an LC Oscillator create a sine wave?
1) ... the capacitor, since there isn't a resistance is shorted, so how can it create a sinesuoidal wave?
The inductor might have a very low resistance (or zero in the ideal case) so it presents a ...
- 180k
6
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Inductor and capacitor for energy storage instead of battery
they do not dissipate energy at least in their ideal case
They do in reality.
Capacitors have a parasitic series resisance called ESR.
Inductors have winding resistance.
Both resistances will ...
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Inductor and capacitor for energy storage instead of battery
Your 0.5mWh amounts to 1800 J of energy.
To store that amount of energy in a capacitor, you would need a 56 millifarad capacitor at 230V.
It would take a 1 henry inductor at about 60A to hold that ...
- 73.5k
6
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Is my answer correct to this non-ideal capacitor question?
I do not fully agree with your answer, the total inductance is about the same for both capacitors (10 uF or 3 x 3.3 uF).
The 3 x 3.3 uF has slightly less inductance. I can tell by looking at the ...
- 81.4k
6
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What are the resonant frequencies for this RLC circuit?
The fun is in determining the transfer function (TF) symbolically otherwise you don't know what elements contribute to the resonant frequencies. You can use the brute-force analysis to determine this ...
- 23.5k
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