About tools to simulate circuits. Specify the tool used.
2
votes
1answer
27 views
ModelSim Altera: simulating the “lpm_add_sub” module?
I'm trying to simulate a verilog module that uses the "lpm_add_sub" module to provide an adder with a separate carry in (for some reason Quartus II doesn't recognise that ...
2
votes
0answers
52 views
Simulating PID controller in Matlab
I am trying to explore PID control with a simulation. My problem is that the derivative term does not behave as expected in my simulation: No matter how large its coefficient it seems unable to ...
0
votes
1answer
52 views
Executing Spice commands written in file
I successfully executed ngspice commands via the command line.
When I wrote those commands to the .net file, and run that file via ngspice, they didn't work.
The ...
0
votes
0answers
16 views
Alternative IBIS model
What do you do when you want to simulate a signal (i.e with Hyperlynx) but you can't find the IBIS model of the receiver chip?
What parameters do you need? Where can you find them?
-2
votes
0answers
40 views
Limits of electromagnetic computation [closed]
How do Maxwell's equations used for calculations and electromagnetic simulation push the limits of our numerical methods and computation tools? What are the modern limitations people in the field ...
-2
votes
0answers
38 views
Working with gEDA [closed]
I want to make a simulation of a simple Buck converter (with freewheeling diode) with gEDA & gSpiceUI.
How do I do that?
I'm totally new to this, it seems difficult to understand.
Do you know a ...
0
votes
1answer
30 views
Logisim - Tunnel that outputs the OR result of all of its inputs
Consider this screenshot:
When the two values differ, I get this:
This makes sense, but it's a problem. I would like the tunnel to function like this: when it's getting mixed values, it outputs ...
1
vote
0answers
29 views
Analysing Signal quality through pogo pins using Hyperlynx
I have successfully modeled Linesim and boardsim schematics for quite a few designs in the past and we have been able to do the required SI simulations. I had one question though: On one of our ...
2
votes
2answers
90 views
How to simulate a circuit with LM2576 in it?
Background: I am software engineer with a limited knowledge of electronics. This is a n00b question.
I want to design a circuit to step down DC voltage from about 24V to 12V. I have tried a 7812 ...
7
votes
1answer
164 views
Understanding a high voltage generator circuit
I found a thread in the forum about a high voltage power supply 3V to 500V DC converter and someone suggested a circuit from techlib H.V. generator for Geiger tubes:
However,when I tried to ...
0
votes
1answer
31 views
Circuit Simulator for sampled Input
I would like to be able to capture a signal from my DSO and run it through a simulator to allow me to develop a simple analog preprocessor for a brushless motor speed sensor. Please correct me if I'm ...
1
vote
0answers
52 views
Program to simulate seven segment display in atmel studio
I am using Atmel studio for the programming of atmega64 microcontrollers with a Cerebot board II.
Firstly, is there a program that can simulate a seven segment display device as if I was looking at ...
1
vote
2answers
68 views
Assignments with after and signals
I am trying to understand how assignments with 'after foo' work, so I read about the delay model and simulated the following code:
...
3
votes
2answers
78 views
Heat Activated Alarm
I am working on a project in which I have to simulate a heat activated alarm. I have attached two images. One of which is a Proteus circuit image that i have made. When i start its simulation the ...
5
votes
1answer
178 views
How does this LED setup work?
I noticed this LED setup in a datasheet for the Kingbright SA40-19EWA. Instead of the leds being in a simple series or parallel setup, each segment of the display has four sets of two leds in ...
3
votes
2answers
133 views
What is the output voltage of this 555 timer high voltage circuit?
I'm trying to calculate the theoritical output voltage of the following 555 timer high voltage circuit.
It claims to output up to ...
3
votes
3answers
267 views
Simulation for a transmission loop using PowerWorld
I am now learning how to use PowerWorld Simulator. However, I faced some problems when I tried to enter the data given in the paper.
I want to simulate the following transmission loop:
First things ...
2
votes
2answers
80 views
How to improve nasty form clipping behavior in differential input stage
The amplifier in the following schematic, when simulated, shows that it can cleanly amplify a signal with 0.1V amplitude to 10V. When driven with a larger signal, though, the behavior is very nasty in ...
2
votes
1answer
73 views
Logisim - wire holds value 'e' when zoomed out, but not when zoomed in
I'm trying to make a multiplier in logisim. This is a full picture of my schematic:
As you can see, there is an 'e' coming out of my 'XXXXX-XXX00' adder. But, when I look at the schematic for ...
3
votes
1answer
133 views
SPI routing question…Maximum length SPI can be routed
Basically my question is regarding maximum length of SPI routing, and route efficiently in my scenario and any timing issues(Setup and Hold).
I am just explaining my scenario. Please bear with me, it ...
4
votes
1answer
133 views
Simple LED model for circuit simulation
I'm new to electronics and I'm learning the basics for a small home project involving LEDs, fiber optics, and microcontrollers.
I'd like to simulate the circuit I plan to build to get a better ...
0
votes
2answers
77 views
Flip signal values in verilog simulation
I use "force" command in modelsim to force an internal signal to a specific value (not primary inputs). Sometimes, the value I force is the same as the original value.
Is there any command that can ...
1
vote
3answers
71 views
Simulating Altera FPGAs with an old version of ModelSim?
I'm hoping to do some development work on Altera FPGAs that will likely be larger than is supported by the free edition of ModelSim. I have an old copy of the full version hanging around (version ...
2
votes
1answer
60 views
How do I measure the characteristics of a voltage divider in a QUCS simulation?
How do I measure the characteristics of a voltage divider in QUCS?
Below is what I have tried thus far, using Qucs 0.0.15 on Ubuntu 10.04
I want to measure how the voltage at the center of a ...
2
votes
1answer
159 views
Logisim: timing problems setting register
I'm having some problems understanding the timing behaviors I observe in Logisim. I've isolated some cases which illustrate the problem.
Say I have a register (1-bit, to keep it simple), which is ...
1
vote
0answers
91 views
Simulation of a circuit
I am trying to simulate this circuit i want to know if the circuit i assembled is correct?
i want the current of VCCS element 1 and 2 plotted on a graph as i vary Vtun, Vsprog and Vdprog. I am ...
1
vote
0answers
86 views
What software do people use to make digital circuit schematics? [duplicate]
What software do people use to make electronic circuit schematics like this or similar.I tried using multisim but it seems to miss most chips.
1
vote
2answers
165 views
Defining a nonlinear capacitor in Ngspice
I try to simulate an electronic circuit depicted in the schematic below.
This circuit contains two nonlinear devices :
These two devices are depending on the charge density and are defined as ...
2
votes
1answer
157 views
How to modify spice transistor model
I have a few transistor (example 2n3906, 2n2222, etc) models and have used them with ngspice & gnucap with no issues.
I would like to use another transistor (example 2n4401) but I am not able to ...
2
votes
1answer
222 views
Constant current battery discharge
I'm simulating NiMH cell discharge from 1.5V to 1.0V. The circuit I drew is supposed to draw a constant current from the battery.
I simulate a DC Sweep in circuit lab but somehow the current draw ...
2
votes
2answers
228 views
Calculating photodiode current based on A/W for simulation
I'd like to simulate photodiode current for a silicon photodiode, one example device the project may use has the following specifications:
Based on the above plus a guess at Rs for the moment from ...
1
vote
1answer
225 views
How can I model this linear power system in MATLAB?
For my power system, let us suppose it has the following dynamic model: \$\ x ' = f(x,u)\$.
This dynamic model consists of four first order differential equations (see below).
Then, I linearized ...
1
vote
2answers
72 views
Spice_ Capacitors in series
I try to simulate an RLC circuit depicted in the annexed file. I have noticed that ngspice is not able to compile two capacitors which are connected in series. The netlist is written as follows:
...
1
vote
2answers
222 views
LTSpice simulation of rectifier slows down after short time
I have the following simple circuit set up in LTspice:
Blue is on the output of the transformer and green from the rectifier.
If I don't include a capacitor this works fine and the simulation goes ...
3
votes
1answer
141 views
Battery Charging - Electrical Model
A common technique used in battery charging algorithms is Constant Current / Constant Voltage. That is to say, initially a battery is charged by applying a constant current (which I believe is what is ...
0
votes
3answers
157 views
Matrix and simulation
I came across a simulation software called MATLAB. I got to know it takes inputs in the form of matrices, provides output in terms of matrices , all in all it operates using matrices. But it seems ...
0
votes
1answer
128 views
Code Error 9 In Modelsim
When I am trying to do simulation of the following program on Modelsim Altera 10.0d then gives Error : Code Error 9:
** Fatal: (vsim-4) * Memory allocation failure.
Attempting to allocate 131072 ...
1
vote
1answer
131 views
Diode Bridge in Simulator not behaving as expected
Hi I have a Diode Bridge as outlined in the image below. As you can see I am getting a negative voltage on one pair of diodes instead of this voltage being flipped to positive.
Can you see anything ...
1
vote
2answers
135 views
Value of M-Ary?
Here, I want to simulate an M-ary [pulse-amplitude modulation] system. Anyhow, I chose my binary source to generate information at a rate of 1Mbps. The data "virtually" has a zero intersymbol ...
2
votes
1answer
109 views
Simulating IBIS Model in modelSim
I am developing a logic in an FPGA that will act as a controller for a chip by TI. I got the TI chip IBIS model from the TI website.
My controller is ready and I want to simulate it using ModelSim. ...
2
votes
1answer
87 views
Is there a way to open/import gschem .sch file in qucs?
Is there a way to open .sch files produced by gschem in qucs? The two applications use different file formats. Does anyone know if a converter exists?
7
votes
1answer
250 views
Why does this simple VHDL pattern for a shift register not work as expected
At first glance you would expect the VHDL source code below to behave as a shift register. In that q, over time would be
...
8
votes
1answer
224 views
Cassette Input From TRS-80 - Design Review
I'm working on getting an input from a cassette for a TRS-80 microcomputer (of 70's vintage). This is what I've worked up. It is a second order high pass active filter with rolloff frequency of 2kHz ...
4
votes
1answer
95 views
Simulation of blocking assignments in always @ blocks
Tracking down some weird simulation results, I found that the use of blocking assignments at clock edges was the culprit. More specifically, different simulators seem to treat them differently.
Take ...
0
votes
0answers
179 views
problem using avr-gdb, simulavr and ddd
I wanna debug an AVR program with avr-gdb while using simulavr as the simulator, as long as I'm not using ddd, things work, but once I use ddd for some graphical interface, as I'm new to gdb, the ...
1
vote
1answer
223 views
Simulation of Band-Pass Filter (RLC) in ngspice
*I think I've found the answer myself. Check out the question comments.*
Sorry for my bad English, I'm still learning it.
This week I started using ngspice. I've built some simple circuits to get ...
0
votes
1answer
265 views
Peak detector is not working when voltage is changed
I am trying to design a peak detector in Multisim simulation tool. I have designed buffered peak detector to get peak voltage of sine signal. The designed circuit is working when signal voltage is ...
0
votes
2answers
173 views
Doesn't quartus II support simulate with a verilog file?
I want to simulate my module StreamLight ,So I create a Simulatefile module:
...
1
vote
1answer
120 views
Can I create a verilog file to both simulate and synthesize?
Recently I was reading a Verilog study book. I finally realized that a Verilog file may not be synthesizable, because some Verilog statements are for simulation use only. But I'm too lazy to make one ...
8
votes
3answers
338 views
A decent library of component simulation, schematic and PCB layout?
I am truly a novice in PCB design, so I am new to all aspects of it. What I am having the most trouble with is actually picking suitable components. The trouble I am having is that I am not really ...
