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
48 views

Recommend resource to perform Mathematical calculation to learn and design small electronics circuits by myself [duplicate]

Basically I am a software engineer. But whenever I see any electronics device like FM transistor , LED dancing lights or TV remote control etc ,it attracts me very much. Whenever I get a free time , I ...
0
votes
0answers
11 views

Replace hybrid-pi model with proposed Thevenin model

This lecture (page 10) shows how to replace hybrid-pi model with proposed Thevenin model. Could you tell me how to calculate \$A_{v}\$ to get the result as in the page?
1
vote
1answer
84 views

Producing a sinusoid from a DC input

Here is a simple circuit that I have built which takes as input a DC voltage and gives out a sinusoidal output varying from -V to +V. It has three parts: (1) A LC circuit, (2) a buffer to isolate the ...
2
votes
2answers
41 views

The Thévenin equivalent has an equivalent I–V characteristic only from the point of view of the load

I am reading about Thévenin's theorem on the page. As you can see from the Practical limitations section, there is a one shortcoming that I don't understand. The Thévenin equivalent has an ...
1
vote
7answers
76 views

Why should we set input source equal zero for calculating output resistance of common source amplifier?

This lecture (page 10) gave derivation of common source output resistance. What I don't quite get here is why we should set the input source equal 0 for calculating output resistance. Could anyone ...
1
vote
2answers
34 views

Optimizing regulator power circuit for low noise?

I am trying to understand the attached circuit. It's an ADP3333ARMZ-3.3-R7 regulator to provide 3.3V to an analog system. My goals is to have a very low noise regulator and power circuitry for a 16 ...
1
vote
3answers
51 views

Open circuit resistance in common gate amplifier

I am reading about common gate amplifier on this page and there is a small signal model that I am a bit confused. The common gate amplifier and its small signal model is shown below. As you can see ...
2
votes
1answer
73 views

Could anyone tell me what is the usage of the circuit within the red frame

The whole circuit is used for measuring voltage, but I am wondering what is the usage the circuit of the red section and how to analysis it? could anybody offer me some anlysis? Pleas ignore some ...
-5
votes
0answers
33 views

knowing which current value to use for finding resistor voltage [on hold]

why do i use the electric current value in V_0_ in the diagram instead of the current through R_2_
0
votes
2answers
91 views

How do I calculate the total resistance of this potentiometer circuit?

Can somebody explain to me how to calculate the total resistance of the circuit in the picture? I do not understand how to deal with the potentiometer and the red line. Does the current flow over \$...
0
votes
2answers
47 views

What happens with voltage phase on the resistor and capacitor in AC circuit?

I'm currently studying AC circuits and I find it difficult to understand phase differences between voltage and current on different components. For example, let's look at this circuit: And here is ...
-13
votes
0answers
96 views

hopeless right now. electrical/mechanical engineering question [closed]

to be honest i dont even know where to start with this. if anyone can answer and explain to me how you did it would be much appreciated. thanks in advance
-4
votes
4answers
110 views

If I sent a message through a single-circuit telegraph across a copper wire to the Andromeda galaxy, will my message be received instantaneously? [closed]

I recently learned that electric current flows like a bicycle chain where all the electrons push each other at the same time. This got me thinking. Would this have the same effect at an astronomical ...
0
votes
2answers
63 views

Will light turn on in a closed circuit for a moment if a diode stops electric current after light source is reached?

I drew an example of the closed circuit I was thinking of for my question. Below I have the diode stopping the electric charge after it has already passed through the light bulb. My assumption is that ...
1
vote
2answers
41 views

Electronic circuit analysis: Find V_out with several MOSFETs

I have a question about an exercise from my electronic circuits class, number a): Find an expression for the large signal V_out at DC. Since it is DC, we can ignore the capacitor, it will act as an ...
0
votes
1answer
90 views

What is the role of the resistor at the input of the OpAmp? [duplicate]

Could anyone explain the role of resistor R1 in the circuit below? Thank you.
0
votes
1answer
48 views

How to modify this tank circuit to obtain a 3rd order passive band pass filter?

I am very confused about band pass- and band rejectfilters. I have this circuit which represents a bandpass filter. A 2nd order (2 energy exchanging elements) bandpass filter if I am not mistaking: ...
3
votes
3answers
148 views

Why filter through hardware?

I am trying to measure a signal with a voltage amplitude between 10-100 microvolts and a frequency between 7-30Hz. The guide I am following suggests filtering out 60Hz noise using a notch filter, as ...
4
votes
0answers
32 views

Circuit feedback with mutual inductance on a toroid

I have been reviewing a circuit for the past few days and I am hoping to get some feedback to verify my thoughts as to how the circuit is working. This is a driving circuit for an ultrasonic cleaner ...
2
votes
3answers
589 views

What is T1 in this circuit for 'Mains power failure alarm'? [closed]

I know it is a transformer, but is it a transformer that looks like an IC? Or just a regular step down transformer? (Transformer 12V (1A)). This will be built on a breadboard. Also can I use 1n4007 ...
0
votes
0answers
70 views

Guess about the function of this circuit diagram

In a HiFi amplifier from T&A I have found this strange circuit and I haven't any idea what it is for. Maybe for reduce some specific noise or any strange thing for hifi purpose. Anybody seen this ...
1
vote
3answers
145 views

Measuring the bode plot of an op-amp circuit

So a few weeks ago I had to do an experiment and one of the exercises was to measure the bode plot of an op-amp. The instructions told us to measure the voltage and phase difference at the points \$...
1
vote
2answers
108 views

How to ignore pulse in a circuit

I have a 12v cable that sometimes pass (75%on-25%off) and other times 100%on. What can I put on that cable so if the input is (75%on-25%off) then the output is 0v, and if the input is 100%on the ...
0
votes
3answers
134 views

Why is saturation region called so in BJT characteristics?

I understand base-collector (current) linear relationship is lost in saturation region and collector current will be lesser than \$ \beta * Ib \$ . Hence,at max, we can call such a region as non-...
-2
votes
2answers
29 views

equivalent resistance on looking circuit from two different sides

I want to understand how to calculate equivalent resistance if same circuit is looked from two different sides,one from right side and then from left side and how to avoid confusions in this type of ...
1
vote
1answer
48 views

When calculating the voltage in an AC Circuit, I get a different angle from the correct answer

Problem I'am trying to calculate v2 from the circuit below, but my answer, 9.81cos(1000t+166.64°) mV, has a different angle from the correct answer, 9.81cos(1000t-13.36°) mV. My approach I tried ...
5
votes
2answers
76 views

Charge pump circuit with one MOSFET

This is an example of charge pump from MOSFET Models for SPICE Simulation: Including BSIM3v3 and BSIM4 by William Liu. Could anyone explain why \$ v_D = \frac{(v_{IN} - V_T)}{2} \$ here? Why \$ V_T \...
1
vote
1answer
23 views

Low current to HS gate drive in DRV8825 typical application diagram

simulate this circuit – Schematic created using CircuitLab The typical application diagram in the DRV8825 stepper driver datasheet includes a 1MOhm resistor from VM(the motor voltage) to VCP(...
0
votes
0answers
30 views

current in circuit in transient state

simulate this circuit – Schematic created using CircuitLab The switch in the circuit is opened at at time t=0. What is the current through 10 ohm and 20 ohm resistor at t=0(-) and also when the ...
0
votes
0answers
26 views

Nodal analysis question (with supernode)

I am studying for the exam, and found this question. Now, I know that you have to apply a supernode, but I don't know how. Any help is appreciated
-5
votes
2answers
71 views

Why is there no current over resistor next to node?

[n00b alert] I'm wondering why there's no current across the 4-ohm resistor.
1
vote
1answer
51 views

Switching between two devices

I want to switch (toggle) two devices using one GPIO pin and basic components. To achieve that I designed circuit containing one FET driving first device and two FET transistors for driving second ...
0
votes
3answers
55 views

Find v1 and v2 of a summing amplifier when it is in series with another Op-Amp

There is a summing amplifier with two AC power sources (v1+v2,) each connected to a different Ground. Each of these sources connect to a resistor (R1+R2,) and then to a summing point, which branches ...
-3
votes
1answer
74 views

RLC circuit step response

In this given circuit, how can we find \$ Vc(t) \$ that is voltage on capacitor? \$ u(t) \$ is step that is 0 when \$ t<0 \$ and 1 when \$ t>0 $. I want to find \$ Vc(t) \$ by 2nd order ...
2
votes
3answers
68 views

Why reverse polarity causes damage

Is it because it can exceed the reverse breakdown voltage of semiconductors? For instance in low voltage devices say 1-5v is the reverse voltage rated a lot lower than that for damage to occur? Also ...
1
vote
2answers
65 views

Why MOS transconductance is not zero even when drain current is constant?

I am trying to plot transconductance \$ g_m \$ of the MOSFET below when \$ V_{gs} \$ varies from 0 to 1.8V. The schematic is below. The drain current is fixed to a constant DC value 1uA by a current ...
0
votes
1answer
29 views

Derivation of transcondutance gm using Taylor expansion

From the fist page of the lecture, there is a derivation of transconductance of MOSFET using Taylor expansion. As seen from the picture bellow, drain current is a function of vGS, vDS and vBS. iD is ...
3
votes
1answer
44 views

Will there be a capacitance in a wound coil?

A wound coil in general is a series LR circuit. If the coil has N turns, will there be a capacitance in between consecutive turns of the coil? If there is a capacitance, is it parallel to L and R or ...
0
votes
0answers
26 views

Resonant RC Series and deriving equivalent circuit

How is it that this is equivalent? Assuming all transients have died out. vi = Vcos(omega*t) The fake input was defined as: \begin{equation} v_{cp}^\sim = \frac{V_i}{1+j\omega_1RC} e^{j\omega\\_1t}...
0
votes
2answers
78 views

Analysis of circuit

Hi all, So the question for this circuit was: Using logic gates design a circuit which turns on a light if any one of a car's four doors are opened. Assume that each door is equipped with a switch ...
0
votes
2answers
42 views

Calculating true power of a predominantly inductive load?

I'm stuck at this problem, which doesn't seem to be so difficult, but, I guess there is some basic stuff that still confuses me. So, if we have a load represented with complex impedance \$Z=30+j40 \ \...
1
vote
0answers
34 views

I need to find the uppers and the lower bound of 3dB frequency

How can i find the upper and lower bound of 3dB frequency ?? I think I have to make first a small signal analysis including the capacitors Cgs,Cgd ..
0
votes
1answer
93 views

Small signal equivalent circuit BJT question

This circuit is two BJT transistors in so called 'darlington configuration'. I want to analyse this circuit for AC signals (where the capacitors are shorts). The question is to calculate Delta_V_L/...
-1
votes
1answer
47 views

Two-port circuit analysis. Voltage gain [closed]

I am trying to find the general equations for the voltage gain(Not sure if it is the write word for it). My textbook offers an derived equation but not the procedure. I would appreciate it if someone ...
0
votes
1answer
33 views

Asynchronous sequential circuits

How do I analyze a sequential asynchronous circuit? The yellow part is the one I don't get (I know how it works, but don't know how to write it when I do the analysis)
0
votes
2answers
88 views

KVL with multiple source

I am looking at the problem in page 5 of this document. It is an example of KVL (Kirchoffs voltage law). The circuit is as shown below - . I have 2 questions - 1) Why is the voltage -5V ? Is it ...
0
votes
1answer
38 views

Using KCL/KVL to derive differential equation of a mixed RLC-ciruit

I have the following LTI sinusoidal circuit, and I am trying to derive its differential equation using KCL and/or KVL. I need this to derive the Power Factor as function of the components, so I can ...
0
votes
1answer
44 views

ambiguous component values (ex. U01 U47 M47 etc.)

i'm having a hard time understanding components value when it's given in the following formate U01 U47 M47 sometimes it's even worse like 4N7 i know that U for micro, M for mega, N for nano but i ...