Questions tagged [modeling]
This tag covers finding models for electrical and electronic components and circuits
291 questions
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How to identify parametric model of a buck converter?
I have a buck dc-dc converter
My goal is to identify a dynamic model of this circuit. The model shall serve for design of the inductor current control loop. Until this moment I thought the model in ...
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Determine inductive elements in transformer model
A model of a single phase, \$500 \text{V} / 6 \text{V} \$ two winding transformer, with an ideal transformer in the middle is seen below
simulate this circuit – Schematic created using ...
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What should the base value be for energy when using a per unit model for a power system?
What should the base value be for energy when using a per unit model for a power system? Normally, I would fix \$s_{\textrm{base}}\$ and \$v_{\textrm{base}}\$ and use that to determine \$i_{\textrm{...
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How should I make the PWM switch model for a push-pull converter? [duplicate]
I would like to build a PWM switch model for the following voltage-fed push-pull converter (which operates in current mode) to determine its transfer function.
I can handle simple topologies like ...
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Load cell mathematical model
I'm studying a solution for a weight measuring system that's affected by enviroment vibration - a load cell fixed on a "shaky" frame. My first thought was to use a 3-axis accelerometer (or ...
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Why does characteristic equation and DC model equation for drain current in JFETs do not agree?
I am reading Semiconductor Devices — Theory and Application (Fiore) about JFETs in chapter 10 and there are two drain current equations shown that do not agree with each other.
The first equation is ...
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Why is my differential equation for mass-spring-damper model not converging with ode45 in MATLAB?
I am trying to simulate an electronical device that can be modeled by a mass-spring-damper system with an additional non-linear force. The equation at the equilibrium for the system is the following :
...
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Why do many mosfet models exclude Cds in parasitic capacitances?
Why do many models of MOSFET parasitic capacitances not include \$ C_{ds} \$?
(the image taken from this site)
In integrated circuits, MOS transistors usually have four terminals. If we consider ...
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Delay time in crossbars
I was reading a paper on modeling memristive crossbar arrays. I came across this figure which shows how the delay in the crossbar changes with the crossbar size. The figure on the left is for the case ...
- 526
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How do I analyze an emitter follower with a capacitive load?
How do I analyze an emitter follower with a capacitor load?
At 7 MHz, a 1 nF capacitor has impedance of 22 Ω. A simple emitter follower with a 22 Ω Re is easy to analyze:
However, replace that ...
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Cannot get correct output in PSpice with the Buck Converter PSpice Transient Model from TI
I obtained the LM76005-Q1 transient model from the Texas Instrument website and imported it to PSpice. The website also provides a Design Calculator software, so I basically use it to determine other ...
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Diffusion Current for Non-Linear Charge Carrier Configurations
Diffusion current in a MOSFET device can be calculated using Fick's Law per \$J=-qD\frac{d \rho}{dx}\$. It is often taken that the charge carrier configuration (\$\rho\$) across the MOSFET channel is ...
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Extracting equation/formula of drain current for the circuit model
I have simulated this circuit model in LTspice. Now I want to do an experimental fit for the graph for transient analysis of Id. Can anyone help me solving this circuit for Id? Or give me an ...
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Building SPICE models of optocouplers
Looking through this answer about the 6N137 optocoupler I wonder where one can get all those paramaters like Is, Rs, N, various internal resistances, etc. that are used to simulate the optocoupler. I ...
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How can a power converter small signal model predict transient behaviour during a load step which is a large signal disturbance?
I see small signal model being used to predict the Overshoot/Undershoot of output voltage due to a load step.
How do we justify this approach, since the basic assumption of small signal modelling is ...
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LTspice: weird behavior of simple RC circuit
I try to model a simple RC circuit with input of 2 A DC and I get an out voltage (Vc) of 2 TV. I am not sure what I am doing wrong.
EDIT:
This is for MacOS
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Determining the current carrying capability of a hollow cylinder
How can one analyze, to some approximation, the current-carrying capability of a hollow cylinder with a diameter of 3 inches and a length of 6 inches, made from 100 μm thick copper with a resistance ...
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Electrical modeling of multilayer structure
If I have a construction of layers wherein the topmost layer is conductive, followed by two different insulation materials in between, and a bottom structural layer that is a partially conductive ...
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Battery Pack discharge behaviour
i want to simulate the discharging behaviour of several battery packs/modules connected in series to simulate a discharge machine for a recycling facility. I wanted to simulate possible current/...
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How to learn about memristors as a circuit designer? [closed]
I'm trying to learn about memristors to play with it in circuit design. I think it might be more intuitive to do tests and measurements rather than reading maths formulas. The problem is that I don't ...
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Thermodynamics of a simple electrical conductor
I derived an expression for the time constant of the temperature of an electrical conductor and was looking for some constructive feedback.
Initially there is no current flowing through the conductor ...
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335
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An AC motor is a transformer? How?
motivation:
A guy I worked with years ago (~2015) who is an EE said that "an electric motor was just another form of a transformer". I'm not an EE, so I didn't do things with transformers. ...
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What are techniques to fix/compensate parasitic effects that occur at very high frequencies in passive electronic components on circuit level?
There are of course equivalent circuit models for modeling practical passive components using idealized elementary circuit models that reflect the parasitic effects that occur at high frequencies , ...
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Piezo sensor at resonance - equivalent model
piezo materials are commonly modelled with the BVD model
When the piezo is used as a sensor, they are commonly modelled as a current source in parallel with a capacitor because à external force ...
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Is there a way to take this buck diagram and reduce it to an AC transfer function?
I am semi-dangerous with switchers but I've never really delved into the innards of them so I'd like to ask about this TPS23750 diagram. I would like to develop a model of this feedback loop of a buck ...
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What kind of model can be used to simulate over- and under voltage in a Li-Battery pack?
So far I have not much experience with modeling in the field of lithium-ion cells or batteries except equivalent circuit models (ecm)-models which I've implemented and used for simulations in Matlab/...
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254
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Modelling of MOSFET
I was wondering if there's a way of creating a simple MOSFET model that predicts how the following circuit behaves when voltage source V is varied.
As I understand it, if MOSFET M1 is in the ...
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Improving Modeling of Thermal Noise in Radio Antennae
Background
I'm attempting to write a physics simulation code, one portion of which involves the simulation of the voltage observed at a set of \$N\$
radio antennae immersed in some medium due to ...
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127
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Distributed-element model of a series-RC transmission line
The equations for modelling most transmission lines can be based off the telegrapher's equations but the ones I found only account for parallel resistance with the capacitance, but I would like to ...
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JFET mismatch between mathematical model and SPICE
As a sequel of this question, I built a mathematical model for the Id current of the following (same) JFET circuit:
For a simplified model, I took LAMBDA=0 and set ...
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Build simple LTspice MOSFET model for textbook examples
I am trying to build a simple MOSFET model (very simple, no parasitic capacitance, gate leakage, ohmic contact...) using LTspice to simulate school textbook example, but I don't know how to switch ...
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Why does the frequency deviation of a FM wave have different definitions?
Source 1 defines the modulation index in the expression for FM as follows:
As per the expression for frequency modulated wave, isn't the frequency deviation same as Modulation index 'M'?
"The ...
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Why are these commercial MESFET model parameters unrecognized by LTspice?
I am trying to add a commercial GaAs FET model (ATF34143) in LTSpice XVII for simulation. The model is provided on this website (http://www.hp.woodshot.com/hprfhelp/design/SPICE/fets.htm#ATF34). ...
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What are NMOS level 1 CV equation and its main parameters?
I was asked to perform MOSFET CV modeling. I looked through some papers, but I still can't clarify what the CV model equation for a level-1 NMOS is, and I am also not sure what its main parameters are ...
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Equation for diode saturation current in photovoltaic cell model
I've been looking for mathematical models for photovoltaic cells. Most of the references I've found use the following circuit to the model the behavior:
Particularly, the diode current is modeled ...
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Can I model a diode with higher than usual junction voltage in LTspice using the "Eg" and "Vj" parameters?
I want to model a GaN transistor and include a diode to simulate its reverse conduction above ~2 V with an adjusted diode using the following model statement:
...
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Forward diode depletion capacitance formula
Does anybody know the forward depletion capacitance formulas for diodes in spice models?
Background:
The capacitance of a diode in reverse direction usually is dominated by the depletion (or junction) ...
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What is the type of material used for the casing of semiconductors?
I am trying to build some thermal models for leaded and surface-mount diodes and transistors.
Below is a picture of the TO-220 outline I got from the internet. What kind of material is the black part ...
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Error in modelling a photovoltaic panel using Plecs software. What could be wrong?
I have a work titled MPPT P and O algorithm with a buck-boost converter.
The software I am to use is Plecs.
First I wanted to design a photovoltaic model in Plecs. I tried to follow an example I got ...
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Antenna model by chatGPT AI - correct or not? [closed]
I asked chatGPT about a basic simplified model of an antenna according to my conception of it (pasted is the most relevant part of two separate answers).
It would look like this:
ChatGPT AI ...
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Does the method of Similitude apply in electronics and electrical engineering?
In engineering, there is a theory called Similitude, which describes how models and testing conditions must be correctly scaled in order to behave correctly and represent the real thing.
The reason ...
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How to include dead times into the model of the three-phase voltage source inverter?
I have been developing a Scilab model of the three-phase voltage source inverter. I have started with the idealized model where I suppose that in each of the inverter leg one transistor can be turned ...
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Question about the Verilog-A implementation of a VCO
I am learning verilog-A to model analog circuits. One of the examples given in the book is that of a voltage-controlled oscillator (VCO).
The book says the following about how the VCO can be modelled (...
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MNA matrix of a vacuum tube
I've been working on a project involving a digital model of a vacuum tube. We're currently experimenting with a Wave Digital Filter approach.
Now I've been reading Kurt Wegner's fascinating work and I ...
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What happens to reflections when the distance between a capacitors plates is electrically long?
I understand what happens when a transmission line is terminated with a capacitor but what about when the distance between the plates becomes electrically long?
For PCB mounted capacitors I know this ...
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How to model reverse recovery diode in LTSpice?
I wanted to update this subject as LTspice has evolved from this post: How does LTSpice model reverse recovery time?
To sum up the above post answered by Ste Kulov:
As Ste Kulov said, LTspice allows ...
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What is the meaning of a negative capacitance? - Cadence Virtuoso
What is the meaning of a negative capacitance in cadence virtuoso?
Here in the following image, I just want to find the capacitance of transistors using "print-->DC operating point". Can ...
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What is the meaning of "a" and "z" in capacitor value - Cadence Virtuoso
What is the meaning of "a" and "z" in capacitor value? Here is the image:
I think "a" is angstrom, But I am not sure about it.
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Definition of small-signal capacitances calculated by Sentaurus TCAD Mixed-Mode/AC Analysis
I'm currently working on a capacitance model which will be part of a greater compact model for a planar RFET.
I use Sentaurus TCAD to generate capacitance data, which I use to understand the ...
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Obtaining the State Space representation of a microgrid by combining the state space models of the subsystems
I am trying to obtain the state space model of the DC microgrid shown in the figure. It is made of three converters connected in parallel. Each one is modeled with a voltage source that outputs the ...
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