# Questions tagged [circuit-analysis]

Circuit (Network) analysis is the process of finding the voltages across, and the currents through, every component in the network. Consider using in conjunction with tags for the particular analysis technique(s) in question: "nodal-analysis", "mesh-analysis", "superposition", etc.

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### Equivalent electrical circuit changing and power balance calculation

I tried to change this circuit in 3 different ways, but the power balance is not the same. The least power balance that I got was ~ 50W more and we need to find the balance between 0 and 5W. Do not ...
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### How to find current in capacitor from equations for voltage and current source? [closed]

How to find iA when t > 0?
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### I have a basic LED circuit with an STM32F030R8T6 which is not working and I cannot figure out why

Apologies as this is a somewhat vague question but I cannot figure out what is wrong with my circuit/program and I have been stuck on this for a couple of weeks now. I have this circuit I put together ...
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### Single fault protection for battery management circuit

I am seeking design guidance for a circuit that has been significantly simplified to drive the point home. I am looking for options to safely disconnect the battery to protect my circuit in the event ...
59 views

### Converting Balanced Audio to Unbalanced Audio without Damaging Sink

I want to receive a stereo balanced audio signal and feed it into the stereo microphone inputs via my motherboard's header pins. I added about a 30 dB reduction in gain which looks good on the scope ...
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1 vote
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### Input resistance of an inverter op-amp circuit

I need to find the input resistance of this circuit. There are two parts of this exercise: The first one is to find the input resistance of the circuit without the capacitor. The second is to the ...
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1 vote
92 views

### Is RC frequency response related to series RC or parallel RC?

So in playing around with some frequency response stuff I made this circuit: And I found that the cutoff frequency value is set by the Feedback Resistor and the capacitor. Take note that the ...
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### Bathroom Fan switch ground vs Neutral [migrated]

I'm sure this has come up before. I have been reading a lot about improper Neutrals or rather using ground as Neutral. From what I can tell, the Neutral and Ground touch in the panel. I thought the ...
23 views

### Designing a simple UVLO in PSIM

I want to create a simple circuit in PSIM that does the same task as a UVLO (under voltage lockout) that only allows voltage to flow when the voltage is above a minimum level (e.g. 5V). Since PSIM ...
23 views

### Find Vx in the given circuit [closed]

I used mesh analysis and got Vx equals 0 which I think is not possible . i2 = -2 , i1-i3 = Vx and 4-3i1+i3+2i2 = 0 are my findings I have been struggling with this question for almost half an hour ...
50 views

### Finding equivalent resistance if each resistance is 100 ohms

The method to follow here is wye delta transformation, the resistors across red and purple nodes are in series so 2R and using delta to wye in green-pink-blue, and pink-black-blue after that there are ...
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25 views

### Implementation of Gain as a Resistance in an Integrator

I am trying to follow along with a thesis project block diagram but I am fundamentally confused as to how they have implemented the circuit. The above circuit is a delta-sigma modulator but more ...
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53 views

### Equivalent impedance of a circuit

I'm trying to figure out the equivalent impedance of the right side of this circuit (so the capacity, inductance and right resistance) : I see this result in the solution of my exercice: But I don't ...
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1 vote
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### Why does an RLC filter circuit ring?

I have the circuit below. I understand the concept of time constant in both inductors and capacitors. The literatures says ringing because the signal resign in the pass band which have slope very ...
1 vote
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1 vote
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### How do I model the voltage of a capacitor being charged by a buffer?

I have a problem where I am trying to model the voltage across a capacitor in the following circuit: We can see we have a reference voltage source of 1.25V driving a buffer. For T/2 the Capacitor is ...
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124 views

### How do I solve for the total resistance of this circuit with two loops sharing a resistor? [closed]

The values are in ohms. The loop in question is as follows:
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108 views

### I want to understand this circuit and these equations

I have a hard time understanding this circuit that I’ve been given because of the way it looks. I don’t know why, but electrical circuits seem very confusing to me even after reading the chapters to ...
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44 views

### Getting V1, V2, V3 and the power delivered by the 2 voltage sources

Can you help me solve this one, I've been trying to solve it, however, I can't get it right. So far, I am stuck with this equation. Is this right? I am so confused to what I am going to do afterwards.
45 views

### Find expression for the current flowing through R2 at time t after S is closed

This question is from a coursework I had but is past its deadline, I really want to know the answer... Refer to circuit diagram... Essentially, I have to find an expression for the current flowing ...
120 views

### Diodes Problem - Forward or Reverse Bias

Hi, I am stuck on the solution to this problem. I understand that the second LED is in reverse bias due to its polarity, however, I do not understand how I can be sure LED1 is in forward bias. How can ...
54 views

### Thevenin Theorem Problem

I am struggling to find the thevenin equivalent voltage for the following circuit. I attempted using source transformation and mesh analysis by initially transforming the current sources into voltage ...
1 vote
91 views

### What is the purpose of having a diode in a resistor divider supplying VGS of a MOSFET?

The purpose of the below circuit is to keep the output low during the ramping up period of V1. simulate this circuit – Schematic created using CircuitLab What is the purpose of Diode D1 and D2 ...
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### Digimess dual linear PSU

Digimess (UK) seem to have gone to the wall, broken links on their website and phone line unobtainable. I wanted try and get the circuit diagram for my LM3002 Dual 30V 1A supply because the +ve side ...
903 views

I would like to ask how to calculate the R1 and R2 in the following circuit. I have equations $$V_{out} = (I_1 + I_2) \times R2 + I_2 \times 10k\Omega$$ $$I_2 = \frac {2.5-V_{out}} {R_1}$$ which gives ...
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4k views

### Resistance depending on voltage - the chicken and the egg?

If I understand correctly: The resistance of some circuit components (like diodes) depends on the voltage across them. When two components are connected in series: $\frac{V1}{V2} = \frac{R1}{R2}$ ...
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1 vote
100 views

### How do I calculate current flow through a capacitor?

Currently I've only worked out on the time constant and Vo(t). Time constant = RC = (4500 + 1500)×(10 μF) = 0.015 s = 15 ms Vo(t) = 24×(1500/{4500+1500)) I used the voltage divider rule in this case, ...
64 views

### Construction of a Lagrangian function for a circuit

I was reading the paper "Introduction to quantum electromagnetic circuits", by U. Vool and M. Devoret and I am stuck in the construction of a Lagrangian function for the example LC circuit ...
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### 12V battery through a transistor then pump not working

I connected 12V to pump and to a transistor then connnected all of them to an Arduino: It did not turn on. I used this program: ...
126 views

### BJT amplifier design

I am trying to design a BJT amplifier with the given parameters and limitations. The circuit is shown below. Parameters: Vcc = 15 V RL = 20 kΩ beta = 180 Vbe(on)= 0.6 V Cµ = Cπ = 0 Limitations are: ...
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### Creating an iontophoretic circuitry design that is controlled by an Arduino Nano BLE Sense

I'm a beginner in analogue electronic design working on a project that involves interfacing a Arduino Nano BLE Sense microcontroller to a drug patch for iontophoretic transdermal drug delivery. I can'...