Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [circuit-analysis]

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

-2
votes
0answers
21 views

Chromebook power circuit: Surface mounted diode or resistor? [on hold]

I recently enjoyed finding out a mains power short (was working onsite project) has dislodged 2 surface mounted components from my device's motherboard. Thought it would be interesting to repair ( ...
0
votes
0answers
37 views

Boost converter output voltage error

I'm using LT3494a to generate 37v from 6v input. This is my circuit. According to the datasheet, this chip can provide up to 40v output, so it should be able to generate 37v. Also, the simulation ...
1
vote
1answer
31 views

Consistent Current Output From Batteries To DC Motors

I'm new to ECE and as a beginner project I've taken apart an RC car and attached an Arduino to the DC motors with an L298N module for control. The goal is for the car to drive a certain path with pre-...
0
votes
0answers
34 views

PNP darlington pair calculations

I have a 20ohms discharge resistor connected to my PNP darlington pair. I have simulated the circuit in my mobile (every circuit app).please find the attachment for circuit. But here I'm unable to ...
-1
votes
0answers
38 views

Resistance and voltage [on hold]

Will this circuit need the resistance? Similarly what will be the prescribed voltage, resistance for these 3 leds of 3 watts.
0
votes
2answers
41 views
-1
votes
1answer
25 views

What makes the SCR burnt up?

I removed Pin 1 to trace nuisance tripping of this GFCI circuit, and the SCR blows up: From this circuit: Removing pin 1 will make the pin 7 trigger the SCR continuously. But why would the SCR blow ...
1
vote
0answers
35 views

Switched circuit analysis - getting rid of “glue” equations

I have the following circuit: simulate this circuit – Schematic created using CircuitLab I would like to derive 3 differential equations, describing it, since it has 3 dynamic components [Csh, ...
0
votes
1answer
42 views

Finding resistance and how many appliances can be connected

A household electricity system can be modelled as a fuse in series with appliances, all of which are in parallel across the 240V mains supply. In one household there is a 16A fuse in series with the ...
0
votes
3answers
94 views

Power amplifier, does this circuit work?

I found that circuit for a power amplifier. Does it work? I want to build one for myself.
1
vote
0answers
46 views

How to go about finding the transfer function of a non-linear circuit?

Note: The concept of Transfer Function is only defined for linear time invariant systems. Nonlinear system models rather stick to time domain descriptions as nonlinear differential equations rather ...
0
votes
0answers
17 views

Question about LKC LKV

I was answering probably a simple questions and I dont match the same result using the different method to solve that circuit below: My 2 resolutions: KVL: \$\frac{30-V}{4}+2\cdot I_x-\frac{V}{6} = ...
0
votes
0answers
29 views

Ideas for electronics related c++ projects [closed]

I am engineering student ,I have learnt c++ to advance level covering OOPS, polymorphism, inheritance, template. I want to apply my knowledge learnt in my electronics engineering of various subjects ...
0
votes
0answers
21 views

Calculating Load Power in a transformer circuit

I've been learning about AC circuits and they seem pretty straight forward, except when it comes to transformers. I have this circuit and I want to figure out the Voltage and Power at R2, and also the ...
0
votes
0answers
16 views

How to apply Thevenin's theorem in multivoltage(3) sources?

Here is a question I am not able to tackle as the requirement is to solve it by Thevenin's theorem. The question is to find the value of current passing through 20 ohm. I can perform Mesh analysis ...
0
votes
2answers
65 views

How is voltage divided between two reverse-biased ideal diodes?

Suppose we have two identical ideal diodes (without any resistance or voltage drop). We connect these two diodes in series, in the same direction, and reverse-bias them with voltage V. Now we have two ...
0
votes
2answers
53 views

How to construct the DC equivalent circuit of a BJT amplifier

How would the DC equivalent circuit be constructed? I have a vague idea knowing that AC voltage sources are connected to the ground and capacitors are open circuited but what happens to the resistance ...
1
vote
1answer
39 views

Determine the value of Vx if the power dissipated by resistor Rx is 450W and Rx=50 Ohms

I keep getting figures that are out of these ranges. Maybe I am doing it wrong. So far I've been adding the possible voltages with 200V to get a total voltage, then using Ohms's Law to see if any of ...
1
vote
2answers
60 views

Two-port circuit with input/output duality

Suppose I have a circuit with two ports. One port is considered the input, and the second port is considered the output. Assume it's described via $$V_{out} = \frac{V_{in}}{2}$$ Now assume there's ...
0
votes
1answer
53 views

Apparent contradiction in AC analysis of BJT amplifier

Suppose you have the circuit: For an AC analysis we can draw the following circuit: Now my job is to find \$v_{out}\$, which can be easily found by: $$ i_E=\frac{v_{in}}{R_E} \\ i_C=-\frac{v_{out}}{...
0
votes
1answer
91 views

Finding current through an LED in an amplifier using a BJT

Suppose you have the schematic: My job is to find \$I_{LED} \$ knowing that the impedance of the capacitor in negligible against \$V_s\$. Here's my attempt: I intend to do an AC analysis followed by ...
0
votes
1answer
29 views

Find admittance( G ) matrix of a resistive circuit

I am taking Signals And Systems class where I have to calculate the admittance parameter of a given circuit. A given circuit for example: This is tedious and calculating the parameters takes so long....
0
votes
1answer
23 views

NAND Simplified with xy + !x z

I've been trying to work on a few problems, though I'm not sure how to rewrite this a few circuits using only NAND/NOR --> an example is shown below; How am I able to rewrite only using NAND + NOR ...
0
votes
1answer
49 views

Can a system have constant phase response other than +/- 90 deg (and multiples)?

I have seen frequency responses where amplitude response is constant( pure delay) and where phase response is constant(pure integrator). In an integrator the constant phase is -90 deg. In a pure ...
0
votes
1answer
56 views

Bypassing refrigerator door alarm piezoelectric buzzer

My appliances keep beeping at me. How can I deactivate or bypass this refrigerator door alarm buzzer without affecting the rest of the circuit? I thought I could just cut/connect the wires at the ...
0
votes
3answers
87 views

Voltage in RC circuit with unknown frequency

We were given the task of finding the voltage drop across R1 of the circuit below with the following alternatives: 5.8V 4.8V 4.0V 10.0V All given information is contained within the image, i.e. no ...
1
vote
2answers
61 views

Find Voltage of inductor in LC series circuit with resistor in parallel

I have a LC resonance circuit with a resistor between the capacitor and inductor: simulate this circuit – Schematic created using CircuitLab I want to find the Voltage at L1, more specifically ...
0
votes
2answers
45 views

Bosch Glue Pen: Bypassing automatic timeout [on hold]

I have this Bosch hot glue pen. It has an annoying habit of turning itself off. I guess it's probably intended to be a safety feature or a battery saver, but really it's just a nuisance. Can I modify ...
1
vote
4answers
140 views

Op-Amp gain calculation

I'm trying to find R4 that will make: $$\frac{V_{out}}{V_{in}}=-120$$ The operational amplifier is ideal. My attempt: In the '-' input there is a virtual ground, so the equivalent resistor above is ...
0
votes
2answers
71 views

Input impedance of circuit

Given current gain (hfe = 100), internal resistance (hie = 2000), reverse voltage gain and output resistance (hre = hoe = 0), compute input impedance for the following circuit. The problem is that it ...
0
votes
1answer
135 views

Overcurrent protection for DC motor [closed]

I found a circuit to protect DC motors from stalling: this is the schematic: and this is the board I made based on that schematic: When the power is connected to the circuit makes all LEDs on but ...
0
votes
1answer
61 views

How can I find the short circuit current across a and b?

In order to find R thevenin, I need to find Isc across a and b since there's a dependent source. Based on my calculations, Vth=500/3V. I've spent countless hours thinking about Isc,please help.
0
votes
1answer
43 views

Realizing 2 Resistors are in series in an RC circuit

I understand that when the switch is open, the capacitor acts like an open circuit & therefore the current in the capacitor branch would be equal to 0. When I solved the circuit using nodal ...
0
votes
3answers
32 views

Half wave sine form factor example

Hint: in my calculations below, to make math easier, i assume that the diode = ideal(there is no 0.7 voltage drop across the diode) Vrms = 0.707Vp => Vp = 14.1v, therefore Vp(load) = 14.1v ...
0
votes
0answers
45 views

BJT as a switch: what am I doing wrong? [duplicate]

I'm studying the following circuit The image is explicit but as you can see the input measured in the upper terminal is a square wave with \$E_c\$ and \$-E_c\$ as levels. Now I also had no trouble ...
1
vote
2answers
52 views

Bipolar class-AB amplifier analysis questions

I am analyzing the following amplifier schematic Bipolar amplifier I'm wondering if their are any transistors that need to be cooled apart from the 4281A and 4302A output stage transistors? What is ...
4
votes
3answers
486 views

What is the value of the current (i) and what is the right way to do it? [duplicate]

What exactly went wrong with the below method? Here, in the same circuit I am getting a different value for the current in the mid wire only by rearranging the circuit. I was trying to solve this ...
2
votes
1answer
60 views

Nodal analysis in s-domain help

I am learning circuit analysis in s-domain from my textbook "Engineering Circuit Analysis by William Hayt, 8th Ed". I am struggling with the mesh and nodal analysis. In the book at page 583, there is ...
0
votes
1answer
99 views

What's wrong with this Wheatstone bridge?

I was trying to solve this unbalanced Wheatstone bridge and found that the current $i$ in the mid wire is 9A .This result was achieved by using node voltage method. Then I rearranged the same circuit ...
0
votes
0answers
24 views

For given circuit, does the current “io” through the branch equal zero after short circuit ? [2-port network]

The circuit is; simulate this circuit – Schematic created using CircuitLab For given 2 port network, Im shorting V1 to solve for y22 and y12 and apply a current source at V2.[Y-Parameters] ...
0
votes
0answers
31 views

Determine Y-parameters for given circuit. [Used Nodal Analysis]

I am trying to solve this circuit for past 3 hours, no success, so I am posting here. simulate this circuit – Schematic created using CircuitLab I used nodal analysis, I will go over the ...
0
votes
0answers
17 views

Snubber maximum ratings

I'm developing a home automation system, and using a triac to power on/off some lights. My problem is that lights from other rooms when switched on/off are producing noise/spikes and flashing the ...
0
votes
0answers
17 views

Faraday's Law in the transient solution of Rl circuit

Consider RL circuit consisting of a battery , resistance , inductor , and switch .all components are in series . If we close the switch at time t =0 the current will build up until reaching a maximum ...
0
votes
0answers
71 views

Trouble with my homemade induction heater

first of all, I´m not engineer, not physics and not "math-man", so you know this, I can afford explain my problem, I´m building an induction heater following the instructions found in net (I ...
0
votes
0answers
39 views

How to deduce the current function from the graph?

I want to express the current function based on the next graph So using the slope and the coordinates in the third interval the current will be \$i(t)=\begin{cases} 0\,A & 0\,s<t<t_{1}\,s\\ ...
0
votes
1answer
71 views

Output current in collector of BC107

I am working on following circuit involving BC107 NPN Philips TO-92 transistor and voltage source of 4.2 V. simulate this circuit – Schematic created using CircuitLab I got some confusion when ...
-3
votes
2answers
81 views

Why the led isn't glowing? [closed]

Why doesn't the led glow? I am trying to glow my LED For Making Project Of Detectore but it doesn't glow. When i connect this circuit with my full project that time LED Wasn't Glowing After I ...
0
votes
1answer
43 views

How can I use the component CD4538 or a 555 timer on Multisim?

How can I use the component CD4538 or a 555 timer on Multisim for a delay of 1 second ? I want both of the nor gates to be 1 for roughly 1 second when the output of the op-amps is either 01 or 10.
3
votes
0answers
281 views

How is it that two electric currents can travel in opposite directions on the same wire, at the same time, without interfering with each other? [duplicate]

An Introduction to Information Theory: Symbols, Signals and Noise, by John R. Pierce, says the following: While linearity is a truly astonishing property of nature, it is by no means a rare one. ...
0
votes
1answer
76 views

5 to 12 V boost converter not boosting

For my power electronics course, I need to design a basic boost converter that is converting 5 V to 12 V with 0.5 A output current. Below you can see the simulation results. MOSFET is driven by 20 kHz ...