Questions tagged [passive-networks]
Use this tag for circuits that only contain passive components, such as resistors, capacitors, and inductors. This includes RC, RL, LC, and RLC circuits.
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Why are active filters preferred over passive filters?
This question was asked to me in an interview. I replied that passive and active filters both have their merits and demerits :
Unlike passive, active filters provide mechanism for gain adjustment
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How to apply KVL with current source?
In order to write an ODE for the inductor current I have to write a KVL equation that includes the current source. How do I do that?
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Online motor inductance measurement at different rotor angle
I wanted to measure the inductance of PMSM at different rotor angles. I'm familiar with the offline methods of measuring motor inductance but would like to measure a motor's inductance while it's ...
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How to calculate the LC filter output voltage with a specified frequency?
simulate this circuit – Schematic created using CircuitLab
I have a LC low pass filter, L=39 mH, C=0.45 uF. How to calculate the voltage across the capacitor? The voltage can be magnified at ...
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What is the frequency at which a series RLC circuit stores maximum energy?
I was reading about the quality factor of a series RLC circuit. The quality factor is defined as
$$2\pi*\frac{\text{maximum energy stored}}{\text{total energy lost per period}}$$
Here maximum energy ...
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Sign convention to use in Nodal Analysis
simulate this circuit – Schematic created using CircuitLab
We know that current flows from higher potential to lower potential in a resistor. In this question, we make use of nodal analysis and ...
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How to make amplification circuit for WWVB PWM signal from Raspberry Pi
I’m trying to follow this video since I’m experiencing the same problem with my WWVB radio controlled clocks (can’t get signal where I live) and thought it would be a good excuse to learn a bit about ...
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How can my crossover be improved? Efficiency is too low
I have been working on redoing the crossover for a pair of Dayton audio B652 Speakers, and have just been working on it through a breadboard for practice. I bought a bunch of cheap parts from bojack ...
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How do you use an RC filter on an LNA output to reduce unwanted noise?
We designed two low noise amplifiers, one at 144 MHz and another at 440 MHz using this LNA; each design is tuned for the particular band. We noticed amplification at 440 MHz is clean and crisp, but ...
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Solving for current in RLC circuit with Laplace and steady-state solution
The following parallel RLC circuit is example 8.8 in Fundamentals of Electric Circuits by Charles Alexander.
In the example in this text, the current through the inductor i(t) is found to be:
$$i(t) =...
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Potential should be same for zero current
In the above circuit, I have to adjust variable resistor R such that current across Load resistor RL should be zero.
Which means the voltage across RL should be same. Do i have to use KVL supernode ...
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Resources for impedance matching networks
I am working on my first hobby PCB design project that includes RF components. On one hand, I have a 2.5GHz WiFi signal and an 868Mhz LoRa signal.
I copied the matching networks from the reference ...
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Parallel RLC circuit doesn't produce expected results in Multisim
I am trying to create AC from DC. My device is based on the transient response of a parallel RLC circuit:
simulate this circuit – Schematic created using CircuitLab
If there is some energy ...
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Finding the transfer function and damping coefficient an LCR circuit
I am trying to determine the general transfer function of the following circuit.
Shouldn’t the transfer function just be \$R + \frac{Z_CZ_L}{(Z_C+Z_L)}\$? I am trying to then use the transfer ...
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How to match a network over multiple frequencies?
I'm trying to match the following network using the Matching Network Designer so that the resistance curves (solid lines) get pulled towards the horizontal line and the reactance curves (dotted lines)...
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How to find a linear RLC circuit from its transfer function?
I have a transfer function, for example:
$$H(s)= P\frac{10}{s(s+5)(s+9)}$$
See the figure below.
How do I make a linear RLC circuit from this transfer function, without using an op-amp, but a linear ...
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How to implement a passive RLC circuit from transfer function?
I'm designing a passive filter for a power electronic circuit.
Theoretically I have obtained a transfer function of a passive filter that fits my requirement. But I don't know how to implement it ...
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What is the difference between Smith charts plotting Z11 and S11?
Background
In the process of trying to fix an LNA input impedance match, we discovered we need to understand more about Smith charts! The question is the at the bottom of this post, here's some ...
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Algorithm for impedance calculation from known I and V sinusoids, L and C unknown
I am trying to extract the impedance from a sampled signal. Specifically, I have only noisy samples of a sinusoid, of a single period, of current and voltage at a given known frequency. I am trying to ...
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Unexpected output from LC circuit
I am trying to get back into some electrical engineering basics, and had a quick question regarding an unexpected output I am seeing. I am trying to learn about RLC circuits again, and wanted to build ...
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Synchronization of two RLC circuits
simulate this circuit – Schematic created using CircuitLab
Suppose x amperes passes through the resistor R in circuit 1. Now if both switches in circuit 2 are turned on in synchronized manner, ...
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Parallel RLC time domain response, with two specified initial conditions and no driving source -- it is an homogeneous system
This question is inspired from Andy Aka's question from almost 5 years ago. It is also a nod of my respect to Andy. But what I wrote there is kind of muddled. And it only addresses the under-damped ...
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Does the impulse response of a system include both its transient response and steady state response?
Suppose you connect a circuit containing passive elements like resistors, inductors and capacitors to a voltage source. Now you provide an impulse to the circuit. Is the response by the circuit the ...
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Non Zero Voltage Across LC Series Resonance Circuit
I'm simulating a series resonance RLC circuit using the TINA-TI. The resonance frequency for the circuit is 85 kHz. I did notice that when measuring the voltage across the capacitor, the voltage is ...
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Painfully Yet Steadily Growing Oscillator Output
I have worked out an LC-based Colpitts Oscillator (sharing the schematics) that produces output which grows painfully slow from 10 pV to 500 mV in more than to 3 minutes and settles there. Despite ...
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Finding resonant frequency in a circuit with no inductor
I have a parallel circuit and I need to find its resonant frequency. However, there is only a capacitor paralleled with a resistor and there is no inductor included. So is it correct that in using the ...
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Unsure where to start with AC circuit analysis (RLC)?
Here's what I do when I see a problem like this one below:
On the left side of the circuit I see resistors in parallel, I calculate 1/20 + 1/20 and then take the inverse. Then I add the 10 Ω resistor ...
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Calculating the current through a time-varying RLC series resonant circuit
As shown in the circuit below, an admittance \$Y\$ consists of a series resonant circuit \$Y_m\$ and an additional capacitance \$C_0\$ in parallel.
\$Y\$ is given by
\$Y = j \omega C_0 + Y_m = j \...
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Square vs Round Air-core Inductors for RF filters: When would you use one vs. the other?
The Kyocera AS-series Square Core Inductors boast that "the unique square cross section of the air core inductor provides better performance, and offers manufacturing advantages over toroidal ...
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Quadripole paradox?
There must be something fundamental I am missing about two-port quadripoles and network theory. I tried to devise the simplest possible example to clarify what is my problem. Here it comes.
The ...
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What are the possible causes of an LC low-pass filter not attenuating in its bandstop?
I've got an AC-DC power supply which has an amount of ripple which is unsatisfatory for my application, ~250 mVpp, sometimes even 600 mVpp when there is a DC-DC downstream (for some reason).
I'd like ...
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Reasoning behind the initial conditions of a series RLC circuit
I'm trying to solve the following RLC circuit:
I got the corresponding differential equation and solved it. All that's left to do is to apply the initial conditions.
It's clear to me that \$I(0^+)=0\...
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Two-Port Network with Sources. How to cascade the Chain Matrix?
From EMC Analysis Methods and Computational Models by Tesche on page 61 we can see a chain matrix representation of two-port networks with sources (as seem in the attached image). Lets assume I have ...
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How to solve this problem using transient time-domain analysis?
Find V0(t) in this circuit assuming zero initial conditions.
I solved it (refer image above) using frequency-domain analysis using Laplace and found the answer, but I am not able to get the same ...
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RE46C180 -- disabling chamber checks
There are two types of things one can hook up to the interconnect wiring of a multiple station smoke detector: smoke alarms (with their own detection chamber, control chip, and horn) and auxiliary ...
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LC filter inductor is making noise
Inductor IN3 is making audible noise while I connect to 12V, 830mA supply from an AC/DC converter.
L1 is not present. It has been shorted.
U1 is an LM2576 from TI.
What might be the reason for this? ...
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Passive voltage adder
I have two outputs of a voltage source that do ±10 V with 16 bit. This leads to a theoretical resolution of a bit step of 0.3 mV. My goal is to have more resolution by using a voltage divider of 100 ...
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Initial current
In the following circuit, would the initial current used for the S domain transformation be i(-0)=0 or i(+0)=7/4, assuming the switch closes at t=0, taking into account i(-0)=i(+0)?
simulate this ...
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General statement about arbitrary two-port resistor networks
Suppose I have a resistor mesh that is acting as a two-port network. I'm feeding in \$V_\text{IN}(t)\$ and I'm reading out \$V_\text{OUT}(t)\$. Here's an example of a potential circuit:
Is it true ...
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Charge sharing in capacitors with switching pulses
I can solve the output voltage for the given circuit below as the clock pulses increase. To find a steady-state value, I found the output voltage till it remained constant (around five clock cycles). ...
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Find capacitance such that voltage and current are in phase
I just cannot solve this exercice, any help?
This is what I have tried:
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Designing bandpass filter for audio amplifier
I am a 3rd year engineering student currently working on a project where I need to basically make an ultrasensitive metal detector.
Basically, I need to create an alternating magnetic field by ...
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Series RLC - how does resonance amplify?
A series RLC circuit has a resonant frequency f0. If I apply a sinusoid at frequency f0 to this series RLC circuit, the output of the RLC should be a oscillation at frequency f0 with an amplitude ...
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Synthesizing an impedance given by transfer function (poles/zeros) using a passive network
I would like to synthesize an arbitrary passive network based on a given transfer function (poles/zeros).
The origin is the output impedance of a voltage regulator for which I want to find an ...
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Current source in parallel with a short circuit
If a Dependent current source is placed in parallel with a short circuit,
to solve our calculations would we assume that no current will flow through the dependent source and hence we remove it. For ...
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Creating equivalent impedance for given measured frequency response (that does not involve blind trial-and-error)
I have a measured frequency response and I would like to create an equivalent impedance model for it.
I start with a parallel RLC and then add series R and series L to the elements. I blindly tune the ...
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Magnitude and phase of parallel RLC with series resistor
I have been looking for a while for this issue, but unfortunately I am bit stuck on getting the magnitude as well as the phase of a RLC circuit with a series resistor, seen from V1 (see picture).
...
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What conditions can cause a PCB fuse to fail and act as a resistor?
Context: Tx circuit that shoots 24V pulses into a transformer to get 240V out of it. The purpose is to drive a piezoelectric transducer.
The circuit itself has a fuse protecting it at the entrance (...
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Which matrix index should be used when Y (admittance) is shown to compose a circuit segment mapped to an ABCD matrix? Y21? Other?
I would like to cascade a serial capacitor with a shunt inductor to form an L-match network by multipling two ABCD parameters and convert the result to S-parameters that represent the composite ...
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RLC circuit equation
I want to make equation that describe relation between vi and vc.
I did it like this. Is this right way?
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