Circuit (Network) analysis is the process of finding the voltages across, and the currents through, every component in the network.

learn more… | top users | synonyms

0
votes
0answers
51 views

Why does this State-Variable low pass filter overheat when turning up resonance?

I am trying to build an audio-frequency state-variable resonant filter. Power supply is ±15V. The circuit contains three TL072 op-amps and three LM13700 OTAs. It receives audio input from -2.5V to ...
0
votes
1answer
35 views

Norton Method Problem

$$ I = 1.43 \mu A \space \space R_p=1.8M\Omega \space\space R_s = 17k\Omega$$ I am trying to find the Norton current. This seems like a simple problem, but I keep getting it wrong. I tried using ...
3
votes
1answer
59 views

Component usage in this constant-current source circuit

In the April 2014 edition of Elektor magazine, they present a circuit for a high-precision current source device (page 42). It allows the user to select a constant-current between 10nA and 20mA. They ...
0
votes
2answers
137 views

A cubical LC circuit

I would like to solve for currents through inductors and the voltage across capacitances of the attached circuit. I am trying to figure out a correct method to solve such circuits which could have the ...
1
vote
3answers
37 views

Need help deriving cutoff frequency of output (collector) RC network

According to the book I'm studying, the cutoff frequency for this circuit is given by $$f_c=\frac{1}{2\pi(R_C+R_L)C_3}.$$ I tried to derive it by solving for the frequency at which \$V_{out}\$ is ...
0
votes
1answer
55 views

Simple RC Circuit, switch position

Most textbooks use this circuit as an example of the most basic RC circuit. The solution for V(t) for this circuit is (if capacitor is initially uncharged): I've had an exam recently where the ...
2
votes
1answer
125 views

How can I control a 120v, 1amp fan with a Nest thermostat?

I have a fan (hot, neutral, ground) that requires 120V and uses 1amp max. I'd like to be able to control this with a thermostat so that the fan turns on when the temperature is above a certain set ...
0
votes
1answer
81 views

circuit diagram for uninterrupted usage of a 12volt 1amp device using 12 volt 7ah battery with auto charging and full charge cut off

I have a modem which runs at 12Volt 1Ampere , also I have an UPS battery of 12volt 7Ah. I need to design a circuit so that during power outages my modem works from the battery. also a circuit ...
1
vote
2answers
64 views

Time domain and Frequency domain

what is the difference between time domain and frequency domain components? How do these domains differ from each other?
0
votes
0answers
29 views

Breaking down currents into mesh currents?

I have drawn a circuit above, but instead of components, I've just drawn squares to act as black boxes for components. In this hypothetical circuit, say the currents are as indicated in the ...
0
votes
2answers
50 views

Proff of that in RLC circuit in series where AC source works in resonant frequency the sum energy of the inductor and capacitor is zero at all time

can anyone help me please prove the statement that: In RLC circuit in series where AC voltage source works in resonant frequency the sum energy of the inductor and capacitor is zero at all time. I ...
0
votes
1answer
25 views

what is the dependence of Current through inductor in parallel RLC CIRCUIT with a AC source at resonance frequency

Consider the parallel RLC circuit simulate this circuit – Schematic created using CircuitLab Assuming $$ C,L> 0$$ $$ I(t) = U(t)*cos(t/(LC)^(0.5)) $$ So, we have a source that starts ...
0
votes
2answers
66 views

Where does the term “lumped” come from anyway?

I think I understand the idea of dealing with lumped circuit elements in electrical engineering, but how did they come up with the name "lumped"?
0
votes
2answers
73 views

Why am I not able to simulate a circuit as it is given in a problem?

I'm currently in the process of working through some circuit analysis books on my own. Though it's easy enough to compare my answers to those given in the appendices, I figured that it would be ...
0
votes
1answer
50 views

Need help finding my mistake using Thenevin's Theorem for this circuit (not homework!)

So I have the following circuit (an example from my textbook). The answer for V_o is 3.88V. I got the wrong answer and I'm not sure where I went wrong. I know I could solve for V_o using other ...
0
votes
4answers
58 views

Number of independent KCL equations?

When using nodal analysis, my book says you will always end up with \$n-1\$ linearly independent equations, where \$n\$ is the number of nodes. Can someone intuitively explain why this is true? If ...
2
votes
2answers
112 views

What actually happens in a RC circuit?

I'm currently working my way through a beginner's electronics book(electronics for dummies) where i am introduced to RC circuits as shown in the schematic below. simulate this circuit – ...
0
votes
1answer
62 views

Measuring voltage output in a voltage divider

I'm currently working my way through Electronics for Dummies, where I am shown a simple voltage divider circuit consisting of a 9V battery and two resistors, R1 (12,000 ohm) and R2 (15,000 ohm). ...
0
votes
2answers
177 views

Ohm's Law for voltage divider

I'm currently working my way through electronics for dummies, where I am shown a simple voltage divider circuit comprising of a 6V battery and 2 resistors, R1 (220 ohm) and R2 (1000 ohm) in series. ...
1
vote
1answer
53 views

Resistors in parallel?

From what I understand, the proof is suggesting that $$i(t) = (\frac{1}{R_1}+\frac{1}{R_2})v(t)$$ implies that replacing the two resistors with 1 resistor of value \$\frac{1}{R_1}+\frac{1}{R_2}\$ ...
-4
votes
1answer
75 views

Equivalent resistance problem

I'm trying to find the equivalent resistance to this problem. The 6 ohm and 3 ohm resistor are in parallel since they connect at both ends. What would be the next step?
0
votes
0answers
59 views

State Variable Filter analysis

I'm in the process of making my own adaptation of the classic State Variable Filter (SVF) in the analog domain. Reading up on this article. I discovered that they use superposition to get the ...
0
votes
2answers
63 views

Get transfer function from electrical scheme [closed]

Is there any software/SPICE tool in which I can draw electrical circuit and after that, software prints the transfer function in Laplace domain? I will find this kind of tool very helpful and ...
1
vote
1answer
68 views

Using Pspice to analyze BJT transistor

As always I have a rookie question. In a project, I need to analyze the circuit below in a way that the transistor would be in forward active mode. I need to calculate resistors and voltage sources, ...
1
vote
1answer
177 views

Voltage drop in RC filter

There is something I'm struggling to understand about passive RC filters: When considering a simple low pass RC loop, what exactly is the gain/output at DC and low frequencies? I've been assuming two ...
0
votes
1answer
104 views

Cascade BJT [ Exercise solve ]

How can I solve this circuit for \$\beta = 100 \$ , \$V_D = 0.7V \$ and \$V_{BE}= 0.7V\$ and arrows go to power \$V_{DD}=9V\$ simulate this circuit – Schematic created using CircuitLab ...
1
vote
3answers
79 views

Question about thevenin circuit analysis with voltage across voltage source

I have a certain circuit in mind and I want to find its Thevenin equivalent resistor: I see that there is an dependent voltage source so I add a voltage source of 1V between a and b and make the ...
-2
votes
0answers
62 views

Thevenin & Maximum Power [closed]

Please guide me in the correct direction to solve this question. What I have tried is shown in the image.
0
votes
1answer
33 views

Determining the voltage labeled Vx by Nodal Analysis [Voltage Controlled Current Source]

How to find the voltage labeled v(x) by Nodal Analysis? The sum of currents from node 2 to node 0 is equal to 0. However, I do not know the the current of 0.1Vx. How to solve the question? Thank ...
4
votes
1answer
60 views

Calculating the current of an AC circuit

My goal is to calculate the current i(t) up in the right corner. Using the formula $$ Z_{total} = \left( U\over I\right), I = \left( U\over Z_{total}\right) $$ Given values are $$ R_{1} = 1k ...
0
votes
2answers
97 views

Tried connecting 2 things two 1 battery, smoke ensured

I'm assembling a quadcopter and have run into a problem So, I have one two cell LiPo battery if I've understood things right, it outputs about 7.4V and has one ampere hour. Now, I have one radio ...
1
vote
2answers
58 views

Link between zero state response and the particular solution for an everlasting exponential input

In an LTI system, when the input is the characteristic function (i.e. an everlasting exponential function say \$e^{st}\$ ), the ZSR which is obtained by the convolution integral with \$h(t)\$ is ...
1
vote
0answers
81 views

Node Voltage Analysis with independent and dependent voltage sources

simulate this circuit – Schematic created using CircuitLab I'm having trouble solving for the voltage drop across the 80 ohm resistor using the node voltage analysis method. I can get the ...
2
votes
3answers
217 views

How to deal with a complex circuit of resistors and capacitors?

simulate this circuit – Schematic created using CircuitLab Assuming i have the circuit from above and i need to find the current through every resistor and capacitor. the switch opens at ...
4
votes
2answers
307 views

Why use only oversimplified/ideal equivalent circuits?

Most circuit analysis books use ideal resistor, inductor, capacitor and don't even bother to show practical circuits of these components, let alone any solved examples with practical circuits. For ...
-1
votes
1answer
48 views

Vorperian - Fast analytical techniques problem 2.1d [closed]

I am working my way through Vorperian's book Fast analytical techniques for electrical and electronic circuits, and I've run into some trouble on problem 2.1d... There is a sub-sub question that ...
1
vote
3answers
122 views

Calculate voltage, current and resistance in a complex mixed circuit

How can I calculate voltage and current on each resistor (especially R5) in this circuit? What is its overall resistance? I have no idea how to do this.
2
votes
2answers
209 views

Finding equivalent resistance for time constant in R-C circuit

Given the first order circuit above. The switch has been closed for a long time and is opened at \$t=0\$. Find the equation for the voltage \$vc(t)\$ across the capacitor after the switch has been ...
1
vote
2answers
133 views

AC analysis of a circuit including variable resistors

I have a problem concerning the AC analysis of a simple circuit, containing variable resistors (each variable resistor is a pressure sensor). I am sure this is quite simple, but I have never worked on ...
2
votes
2answers
249 views

BJT: What exactly is an AC Load line?

The DC Load Line is simple to explain, for a given circuit the relation between VCE and IC must comply to the KVL relationship for that circuit. In the graph we can choose a Q point, and then see if ...
1
vote
1answer
37 views

Nodal analysis with dependent voltage source

I need help figuring this problem. I'm reviewing for my final and I can't figure out how to write the nodal equations. What I have so far is: $$6I_x = V_2- V_1 $$ KCL @ V_1: $$7A + \frac{V_1}{10} = ...
1
vote
1answer
75 views

Help understanding how to use Thévenin's theorem in order to solve a first order circuit

simulate this circuit – Schematic created using CircuitLab Assuming the above circuit is given, and I need to find the voltage V on the capacitor for all t (v(t)). The controled current ...
0
votes
3answers
78 views

Circuit analysis of active LP-filter with 2 OP amps

So this is our diagram: We want to find C1, C2, R1, R2 so that our frequency cut-off is 1kHz. We also need to have R2C2 = 2 * R1C1. So, my first instinct is to: Use KCL nodal analysis Set C1 ...
0
votes
1answer
78 views

Solving the RMS of waveform

I was asked to find the form factor of this voltage wave: But before getting the form factor, I should know the RMS value and the average value of the waveform. Knowing that the ...
-2
votes
3answers
180 views

A few OPAMP questions I have a hard time finding the answers to [closed]

I have a few questions, which, albeit, may seem pretty obvious to a lot of you, but I couldn't find the answers myself, so apologies in advance. Also, the pictures are pretty rough, I know, but that's ...
1
vote
1answer
66 views

RFID tag, simulation and schematics

I am very new to electronics. I know basics of logic circuits. I want to understand how exactly RFID works, is there a way i can design in PSPICE(This is the first software that i got for "googling" ...
0
votes
1answer
47 views

Integrator inputs

I'm giving an integrator a rectified and inverted sin wave. I assumed in my initial design that because you feed the input of an integrator into the negative terminal of the op amp, the signal will ...
1
vote
1answer
106 views

BJT Base Collector short circuit

When BJT's collector and base are shorted, then what happens for the circuit or may I say the change of BJT's performance in the circuit as there Vbc is zero. simulate this circuit – ...
3
votes
1answer
155 views

Difference between virtual and ground plane

Ive created two PCBs, a power board to output a +-5V supply and a midway voltage reference (using the TLE2426) at 0V. This PCB powers a biosignal acquistion board shown in the spice diagram below. ...
1
vote
2answers
101 views

Need solution for this CB BJT circuit

How can I solve this circuit? simulate this circuit – Schematic created using CircuitLab This capacitor confuses me when I tried to do DC biasing. Also when I draw small signal ...