Questions tagged [circuit-analysis]
Circuit (Network) analysis is the process of finding the voltages across, and the currents through, every component in the network.
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How to limit Inrush current from a DC motor?
I'm new to this platform and knows very little about electronics. Please forgive if any of this is dumb.
I wish to create an inrush current protection for my L298N Motor Driver, which drives a 7.5V DC ...
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4answers
90 views
How does this RC pulse generator circuit work?
In this video from Ben Eater, he uses an RC circuit to create a push-button "write-pulse" generator for his EEPROM (discussed around the 14 minute mark) that ensures the write pulse fits ...
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1answer
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How to tell correctly if a circuit is pull-high type or pull-low type?
I have been giving this assignment working with Arduino that would light up a 7-segment component, when a push button is pressed.
Is there an intuitive way of looking at the circuit and recognize ...
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1answer
37 views
Analysing diode and resistor circuit
I'm trying to analysis circuit with parallel circuit of diode and resistor.
the diode is ideal diode with forward voltage of 0.8V, and I'm trying to calculate voltage across D2 and R2 (V_out)
For ...
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1answer
104 views
How to find on circuit why it is burning
I have done a similar design in tinkercad but I don't understand why it is not working..it is burning
and the second picture is the design from a youtube video that it is working properly. I have ...
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1answer
83 views
What is the flow of current with two parallel voltage sources?
Good day ! I am a physics student and not an EE so I'm quite hesitant with approaching this circuit problem. What will be the equations for this analysis? Will their be current in the red line even ...
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1answer
72 views
Metal detector circuit description
I found a circuit for this metal detector and would like to make PCB. I can not find anything about this circuit. Maybe someone would know what this circuit is. What are the best component housings to ...
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2answers
49 views
Solving for voltage across resistor in mesh circuit
Hey all I am once again asking for help on circuit analysis,
Ive done mesh analysis and the results are
Ia = IR1 = 0.1641A,
Ib = IR4 = 7.33mA,
Ic = IR8 = -0.1089A,
Id = IR9 = -0.06373A,
now what i'm ...
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2answers
81 views
Solving for voltage across three series resistor with multiple voltage sources [closed]
I'm new to circuits and I cant wrap my head around how to calculate for
voltage across the three resistors along with multiple voltage sources.
I've attached an image of the circuit.
I have to ...
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1answer
63 views
Circuits : Simulation vs Real World [closed]
I'm asking this question to help many others (specially starters) to have a better understanding about differences that may arise between theoretical/simulation results and real world circuit ...
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2answers
116 views
How to calculate the cutoff frequency for this low pass filter?
I have to calculate the cutoff frequency for this low pass active filter.
I know the formula is:
$$ f=\frac{1}{2\pi \sqrt{R_1R_2C_1C_2} }$$
I don't really know if I should multiply it by 2 since there ...
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19 views
Determining max clock speed using a logic tutor
Data sheets have been provided for all 4 logic gates in the image and I will insert them below as I myself am mostly struggling to understand them due to the majority of information on them. I'm not ...
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1answer
73 views
Isn't conventional current supposed to go from high potential to low potential ? If yes, then why this rule is not respected in opamp using AC?
First, thank you for reading my post. I'm a beginner in electronics. I learned that conventional current goes from high potential to low potential. It has always worked for me in DC and even AC. But ...
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1answer
44 views
Deactivating RF modulator circuit in an Amiga 1200, minimum required parts to remove, worrying about composite video voltage
I'm currently doing some work on the PCB of my old Amiga 1200. In order to play some games I want to revive it by installing a scandoubler/flickerixer that I bought to basically be able to connect it ...
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0answers
40 views
Loop Analysis By Kirchhoffs Voltage Law [closed]
Loop Analysis By Kirchhoffs Voltage Law, Please hepp me to solve these problems
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1answer
85 views
Finding the equivalent resistance
It's just the 3 ohms that got me really confused, because it's connected with the two loops. It's my first time facing such a problem. I first thought that 4 and 6 , 3 are in series so I added them, ...
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1answer
40 views
How to simulate the CNY70 IR reflectometer with TINA or LTSpice
How can I model the CNY70 IR reflectometer from Vishay (click here for datasheet) using TINA or LTSpice.
In particular, I would like to simulate the circuit shown below:
The 4pins on the left side ...
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0answers
121 views
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Transient buildup of capacitively coupled transistor amplifier
I'm trying to understand the following section from "Communication Circuits: Analysis and Design" by Donald T. Hess:
Here \$W(t)\$ is defined by $$W(t) = e^{\frac{q(v_i(t) - v_{imax})}{kT}}...
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4answers
740 views
Definition of RLC resonance frequency
I have found that a commonly mentioned definition for the resonance frequency in an RLC circuit is defined as the condition where the capacitive and inductive reactances cancel each other, resulting ...
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6answers
462 views
In a negative feedback loop, why does increase in v_out lead to increase in v-?
I hope this is the right place to ask this question. (Please let me know if there's a better place to ask this.)
Basically, I'm quite confused about how we check if we have a negative feedback loop.
...
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1answer
37 views
How does ground affect a circuit with a diode, connected to the power source which is connected to a ground and an LED for it to act like a NOT gate?
I was searching for a way to use diodes to make a NOT gate.
I found a circuit online and simulated it in an application.
The configuration has a battery (1),where the negative terminal is connected to ...
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1answer
48 views
Understanding Negative feedback loop circuit with an Ideal Op-Amp
The following is given as an example of a negative feedback loop in my textbook, note that the op amp is assumed to be ideal.
However I do not seem to get the logic behind this acting as a negative ...
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4answers
59 views
Nodal Analysis Current Direction Matters
simulate this circuit – Schematic created using CircuitLab
I'm currently doing a question and it appears to me that the direction of the current matters.
For both the batteries I've assigned a ...
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2answers
76 views
Have I obtained the correct simplified transfer function for this RLC circuit?
Have I obtained the correct simplified transfer function for this RLC circuit?
I am trying to obtain the transfer function for the following RCL circuit. However, the response of the TF that I obtain ...
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1answer
76 views
Icom IC-7100 amateur radio circuit - is this a designed short?
My Icom radio has suffered what appears to be an over voltage fault. It's brand new and it appears as if the DCDC charger/regulator in my car has generously donated extra electrons to the radio and ...
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2answers
51 views
Find Vo of an op-amp circuit
simulate this circuit – Schematic created using CircuitLab
I've tried solving for Vo in two ways, one is I took V+ by voltage divider getting
V+ = V1(R2/R1+R2) = 0.05V. Since V+ = V-, it follows ...
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1answer
70 views
Pole at infinity and zero at finite frequency
Is there any circuit that has a pole at an infinite frequency and zero at some finite frequency? A first-order RC Low pass filter has a finite pole and zero at infinity and it makes sense, I am just ...
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2answers
76 views
Why does my parallel circuit turn off when I connect it to a conductor?
With conductor:
Without conductor:
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1answer
51 views
How to read the circuit to drive the numerical value of Vgs1?
b) How do we know the numerical value of Vgs1? can you show me the exact mash?
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4answers
96 views
How to wire LEDs and CR2032 battery to make it work
I've got a problem and it seems that there is an issue with understanding electronic's fundamentals.
I've got inspired by Jiri Praus video
I am trying to make this Rabbit-shape circuit to work.
What ...
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0answers
28 views
What is being multipled to get rid of denominator in Node Voltage problem
I am trying to work through an example problem of using Node Voltage to find the voltage at Vx of a particular node in AC circuits using complex numbers. The example has the equation setup as:
$$\frac{...
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2answers
134 views
Which is the input resistance of the second amplifier?
If a apply a positive Vs, then D2 is blocked and D1 is working, right? How do I calculate Vo then? I know the formula is: - (input resistance / negative feedback resistor) * Vs, but I don't know which ...
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1answer
34 views
Why am I getting “Grammatical Error” in LTspice?
Why am I getting "Grammatical Error" in LTspice the instant that my transfer function denominator goes from a 2nd order to a 3rd order system? See below.
Please note that the transfer ...
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3answers
114 views
Circuit Analysis Circuit
I have a question about the problem below. I have attached my work, but the answer I am getting a different answer than the given answer. Please explain.
Thank you so much!
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3answers
78 views
Why is the resistance of parallel circuits lower than either of the individual parts
I am watching this tutorial, and topic of parallel circuits came up. In the below image, the combined resistance is 60Ω, which is less than either of its parts (150Ω and 100Ω).
I understand how the ...
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2answers
49 views
Trying to understand negative voltage generation with capacitors and diodes
I want to generate a negative voltage from a possitive rail. To do so, I'm reading this article. Here is the schematics it is depicting, assument the input step is +10V:
I understand that when the ...
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2answers
81 views
Purpose of Cap to Ground in this Circuit?
I came across this circuit and I am curious about the reason for C2 being where it is. If I am analyzing the circuit correctly, this is effectively just C1 and C2 in parallel. What is the benefit of ...
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1answer
40 views
Is this network able to be interpreted as a node and apply KCL?
I've may been asking the really trivial question.
Is above diagram correct?
I interpreted the network as a node and applied KCL.
No such grounded thing is included in the network.
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2answers
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Which graph is correct?
By applying a rectangular signal (of 2 V amplitude) in a non inverting amplifier that has a power supply of +/- 10 V, which one of these graphs is correct?
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3answers
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Space state circuit modeling question
i have a question about this circuit and its space-state modeling. I have the node A, modeled by $$I_{C_1}= I_{C_2}+ I_{R_1}$$
But i don't know what can I do. I already know that $$V_{R_1}=V_{C_2}$$ ...
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1answer
74 views
Are these 2 equations some of general formulas of infinitesimal length?
Given below. \$x\$ is a variable.
\$r:=\text{resistance between the nodes A and B}\$
\$l:=\text{length of the resistor }r\$
\$\rho:=\text{resistance per unit length of }r\$
\$\frac{1}{\rho'}:=\text{...
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1answer
57 views
Using a UA741 IC as sensor for an existing AA LED
I am trying to know if an air conditioning is ON/OFF (Daikin with only Wired Remote Control). I want to read its LED. The circuit is fed by a simple 17.8 V two wires from the machine. I've read the ...
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4answers
593 views
Op-amp homework question using potentiometer with my attempt at solving it
I nearly understood that when Rpot is 0, Vo is highest and when Rpot is 0, Vo is lowest.
So I tried KCL to get Vo when Rpot is 0 (0 turns).
I couldn't get Vo but just 0 volts. What mistake did I make?...
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1answer
52 views
How does this optocoupled smoke sensor circuit work? [closed]
This is an optocoupler module consisting of an infrared LED coupled to a phototransistor as smoke sensor.
I got this circuit from this site.
According to T.K. Hareendran says:
For optimum ...
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0answers
9 views
Why am I getting a lesser negative threshold voltage for my astable multivibrator?
I've calculated my threshold voltages to be +/-5V but when I probe Vout, I'm getting a -6.42V threshold voltage instead of the expected -5. Why is this? I'm guessing it has something to do with R4 and ...
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1answer
57 views
Can someone help me interpret these diagrams?
I am extremely new to electrical engineering, and I am using it for a personal project. I tried looking into circuit diagrams for a part(a pushbutton), and I don't recognize any of the symbols. Most ...
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1answer
47 views
Finding Ro while designing an amplifier
I didn't understand why we are subtracting load voltage from output open circuit voltage in part (c). What is the logic behind it?
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0answers
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Soil moisture sensor circuit how to link the whole scheme
This is a soil moisture sensor circuit, composed of the following blocks: oscillator (green), the electrodes (yellow), amplifier (blue) and rectifier with Trigger Schmitt (red). The schematic turned ...
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0answers
43 views
Philishave (Norelco) HS550 reverse-engineering
My first question here. Image is schematic for Philishave (Norelco in US) HS550 shaver - 110V-230VAC.
I am puzzled how this works.
I think that on the early part of the positive half cycle the supply ...
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1answer
52 views
Problem of resistance of a sphere with a cylinder in exactly one point
I am modeling nerve cords that have fibers (yellow - blue stick) and a cell body (blue ball) :
This is most often modeled using electrical circuits. Now each segment has its specific resistance \$R_i\...
