# Questions tagged [voltage-source]

Anything related to voltage sources, their circuit models and their practical circuit implementations. An ideal voltage source is a two terminal device whose output is a voltage signal with a given waveform regardless of its load, i.e. irrespective of the circuit to which is connected.

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31 views

### what voltages do i need to test on this board for tv not starting [on hold]

can someone tell me why it doesn't say standby on this to test voltages
27 views

### Designing a circuit to fit a v-i characteristic graph

Here is the graph I'm trying to fit a one-port circuit to: I can only use linear resistors, ideal diodes and independent source. Here is what I got: I have no idea how to check this, I just used ...
41 views

### LtSpice antisymmetric sine pulse

I am trying to create a pulse voltage source in ltspice. The pulse should look like a half cycle of a sine wave however the rise and fall times should be different. I can create such pulse with the ...
33 views

### Is the purpose of an internal resistor in a practical voltage source to set the maximum possible current that can be drawn?

Going off the example circuit I attached below, is the purpose of an internal resistor to limit the maximum current that the voltage source can output? Since adding any passive component in series ...
144 views

### Is it possible to reduce the resistance of a voltage source (coil)? If yes, how can I do that? [closed]

First, I should inform you that I am a mechanical engineer, so this is an adventure to me. What can sound as basic to you, is like a new discovery for me. Second, I would like to introduce you the ...
440 views

### Don't individual signal sources affect each other when using a summing amplifier?

I am studying the book Electric Circuits by Nilsson & Riedel. There I learned about "summing amplifiers" and how to derive equations by applying KCL at inverting input of the op amp. I see that ...
57 views

### Simple RC Circuit question: how does a precharged capacitor interact with a lower voltage source?

So, I have this simple question to solve, but I am uncertain about some details. The circuit I have to solve is the one on the image below: I have a circuit with one capacitor(C = 1/4 Farad), two ...
58 views

### Repairing an old Bench Power Supply

I have an old PS-303D from Conrad in use at home. Recently it showed a problem. If I measure with my multi from V- to V+, the voltage reading is correct, current and voltage regulation seems to work ...
57 views

### Calculating source voltage in circuit

Given the circuit I have to find the source voltage S and unknown resistance R3. It is stated that the power dissipated in R6 = 3 ohm is 0.75W. How should I attempt to solve the source voltage where ...
54 views

### Alternative to battery powered isolated voltage source [closed]

For some nano-physics related measurements, a very clean low-noise bias current is required. People mostly use a battery powered isolated voltage source along with a big resistance similar to this. ...
59 views

### Motor only works with alligator cables

So, I’ve run into a weird issue while trying to hook up a voltage controller box to two linear actuators. The voltage controller box receives an input of 12V and outputs 12 or -12 depending on what ...
3k views

### Negative Resistance

I am a bit confused about the physical meaning of negative resistance. Mathematically, a component which has negative resistance shows a decreasing voltage across its terminal when the current inside ...
40 views

### Impedance Matching and Reflection Coefficient

Consider a real signal generator (Voltage Source Vs, output impedance Zs, reflection coefficient Γs) and a load Zl with reflection coefficient Γl. I was told that we have maximum power transfer when ...
75 views

### Superposition with dependent sources

If the value of a dependent source (say CCCC) depend on the value of an independent source (say a current source). When setting the current source to 0, would that make the CCCC an open circuit (i.e. ...
23 views

### Under what conditions does a VSC require a DC-link capacitor?

For basic, conventional converters, such as the three-phase two- and three-level converters, the use of a DC-link capacitor makes sense to me. Considering only reactive power applications, it makes ...
77 views

### Under which specific (formal) conditions can I apply the superposition theorem?

Superposition theorem fails when you have two ideal (identical) voltage sources in parallel. Under which specific constraints can I apply it? I have read that, in DC Circuits, superposition requires ...
111 views

### Digital voltage stabilizer relay diagram

I am using this voltage stabilizer relay diagram below, which provides a 16 step-up level. I need to edit it, so that I can made it to work as step-down in case of high voltages such as 245 and above. ...
37 views

### Actual direction of phasor current - Power Calculation

I am trying to calculate the complex power in this circuit. I used nodal analysis to find Vc, and the voltage at the top of the 2H inductor (=3.13<177.8 V_RMS). I did the math for all elements in ...
129 views

### constant voltage source + constant current source with transistors

I need a "driver circuit" for my amplifier. It consists of a dynamic current source, a constant voltage source and a constant current source like shown below: The constant voltage source should ...
68 views

### Select between two sources with transistors

I'm sorry if this has been asked before but I can't find useful data on this matter. I have two sources of data and I want to select one of them using transistors. If I had to guess I'd make the ...
43 views

### Voltage in a Y-Δ transform

I'm looking for a way to solve the following circuit Without the voltage sources on the circuit, I would be using a simple Y-Δ transform. But I'm not sure how I should proceed with them on. Which ...
39 views

### Source voltage of circuit with diodes when output voltage is given

Tried solving this using KVL, and solving to get the currents for the different parts of the circuit, however got stuck when trying to compute the source voltage especially that I'm unsure if the ...
58 views

### Understanding some mistakes, when trying to find the Thevenin equivalent

I was asked to find the Thevenin-Norton equivelant, and I got stuck on some things that I can't quite understand. I don't know if i need to be more specific. What's wrong with the following? And why ...
49 views

### Network Analysis for finding power delivered

We need to find the power delivered by the 5V source in the above network. I usually apply superposition theorem when I need to find the power delivered by a source when there are many power sources ...
138 views

### What is an example of a three-terminal current-controlled voltage source?

Dependent sources come in four flavors: voltage-dependent current sources (e.g. a FET can act as a VCCS) current-dependent current sources (BJT) voltage-dependent voltage sources (OpAmp as an example ...
105 views

### Combining two ideal voltage sources with an impedance between them

Solving a problem, I came across the following source transformation:        My question is: I know that I can do the following:       &...
155 views

### Source transformation with impedance being inductor or capacitor

I found a presentation that states the following about source transformation when the impedance is capacitive/inductive: While electrical circuits books, like Nilsson's, says: If I transform the ...
72 views

### Measuring change in magnitude of electric current due to change in conducting material characteristics

I posted this in the physics section. I now think this might be more appropriate section for these questions. I am looking for answers to the following: What is the order of magnitude of change in ...
67 views

### Calculating current in one branch of circuit

I want to calculate the current labeled in the diagram $i$. I am thinking that since there is 3V it would be as straightforward as $\frac{3V}{6\Omega}$ for the current in that branch labeled. Is ...
32 views

### Why do we need a minimum voltage here?

Let's assume we have a circuit like this: (Us should be monopolar but I didn't find something like that). simulate this circuit – Schematic created using CircuitLab Negative half wave: D2 is ...
49 views

### Is it a bad idea to connect two Li-ion batteries in parallel? [duplicate]

Suppose I have two Li-ion batteries for smartphones. One could say that if they are connected in parallel, then the voltage given to the device would be the same, but the capacity would be doubled, ...
70 views

### Electrical energy saving [closed]

"You can not pay for the light! This CUTE for years was..." I wonder, what will happen if to do what is illustrated on the picture. I think there are two cases: Hot terminal of left outlet connect ...
232 views

### Voltage of Different Voltage Sources in Parallel with Diodes

I am working on a project in which I will have two different power sources, which I will have to dynamically switch between to supply power to devices. These two power sources will likely be similar ...
60 views

### Behavior of an ECU Digital Output (0-24V) to another ECU (pull-up i guess) input

Recently i had to control a functionality of an ECU using a separate system (another ECU). ECU "A" provides an input pin which if measured in open circuit shows 12V, so i guess it is a pull-up input. ...
77 views

### Current when two batteries (voltage sources) of different potentials are in a circuit

What will happen when I connect two batteries of different potential in a circuit like below? And if there will be a current will it be the same in the whole circuit? How is it possible since ...
199 views

### Logic circuits use current source or voltage source?

Main question: Do logic circuits use a current source or a voltage source? My assumption is that they use current sources because the standard is to use voltage as the indicator of input and output ...
77 views

### What are the operational differences between a battery and a plug-in voltage supply?

I have a neat little circuit with which I am powering an electromagnet. Below is the schematic for the PCB I created. The positive lead of the electromagnet is connected to 12vdc and the negative lead ...
60 views

### Li-ion battery and arduinos custom circuitry

So i have to design a board around a dialog SOC (DA14681). The dialog part supports li-ion batteries, it has a charger and fuel gauge and USB detection (to power device in case both usb and dc ...
67 views

### Powering 12V / 5W device at minimum cost and steady life duration

I want to power one particular device that feeds of 12V (5W) electricity. However this device is intended to be highly portable and as such, I am quite tight on space, which means 12V accumulators ...
390 views

### What will happen if a dependent voltage source in parallel with a dependent current source?

What will happen if a dependent voltage source in parallel with a dependent current source. like dependent voltage source: 4Vx and current source 3Ix in parallel.
27 views

### variable regulation source

I am learning electronics and I want to make a , variable regulation source for a soldering iron, which works at 50W, how much voltage and amps should have the output? For the soldering iron works ...
60 views

### Nodal analysis: how can I represent the current i2 in terms of voltage over R2?

I am doing the nodal analysis of this circuit: I have successfully wrote the current equations for node A, using nodal analysis, that I found it to be: ...
67 views

### How to amplify the output of an on NMOS, connected to zero source voltage?

I am simulating a 3 transistor based XNOR cell using HSPICE. The circuit is shown in the picture. technology = 45nm Vdd=1.1v |Vth|=0.62v In the case of A=1 and B=1, the output is charged through ...
34 views

### AC regime: Serial connection of ideal current generator and impedance and Parallel connection of ideal voltage source and impedance

I have the following two scenarios in the AC regime: Serial connection of ideal current generator and impedance Parallel connection of ideal voltage source and impedance When we have the first ...
3k views

### How Would One Analyze a Circuit with Two Voltage Sources?

I'm studying Circuit Analysis and a sample problem is as follows: I'm not really sure how to approach the problem. My intuition leads me to believe that the two voltage sources are acting against one ...
88 views

### How much current and voltage should be flowing back into my battery?

I am very new to electrical engineering, and one thing that has been bugging me is short circuits. Main question: When I have a circuit, how much current and voltage should be flowing back to my ...
218 views

### Simple way to boost from 24V to 24.8V? (up to 10A) [closed]

Do you know a simple, inexpensive, elegant way of boosting 24V up by just 0.8V, to 24.8V (between 24.5V and 25V)? My current goal is to power LED appliances but my question is not specificaly related ...
467 views

### Convert Current source to Voltage source in Laplace domain

Is it possible, once I've converted the circuit diagram into its Laplace equivalent, to replace a current source which is in parallel with, in this case, a resistor and inductor by the usual V=IR ...