Qucs vs ltspice


  • Electrical – Simulation discrepancy in Qucs with 2N3904 transistor
  • How to: Getting Started with LTspice
  • Commercial Circuit Simulator Goes Free
  • Electronic circuit design and simulation software list
  • some of good samples and projects in the QUCS format
  • Electrical – Simulation discrepancy in Qucs with 2N3904 transistor

    The selection. Model and assignment to the MR1 Memristor component in the schematic determines the the model being simulated. Select the Libraries tab from the Main Dock. Notice: there are 4 different levels for the Memristor Model in Xyce. Each of these correspond to the model parameter sets above. Select the appropriate MRM X file for the model you want to use.

    Model Directive Left click to place the. Model directive on the schematic. Press the Esc key to exit place mode. Enter MRM5 in the param list and model spec field. Click OK to exit the properties dialog. Click and drag the. PARAM symbol to open the setup parameters dialog.

    Enter Rinit in the param field. The default behavior is for the data to displayed in a separate tab after the simulation is complete. You can change this behavior by changing the settings for the schematic diagram. Right click on the schematic and select Document Settings Select Simulations tab.

    Uncheck open data display after simulation checkbox in the dialog. Current Document Settings Click Apply to save the changes. Click Save to save the schematic to the. Then check thebox F1, F2,etc as standard function keys. Run Simulation Toolbar Button Check simulation for errors or warnings.

    See the status bar at the bottom of the Qucs window lower right corner. You can view and messages written by the simulator by clicking the F5 key or selecting Show Last Messages from the Simulations menu. Xyce Simulation Messages You can save the current netlist by clicking the Save Netlist button on the simulation window. If you save the netlist using the button on the simulation window then you can open the.

    Open the diagrams from the drop-down list. Component Diagram Tabular Data Select the Tabular and then left click on the schematic to place the table. Diagram Tabular Data Settings Double click on the tran.

    I PR1 row to add it to the graph. Double click on the tran. V VMR row to add it to the graph. Click Apply to set the value. Click OK to save the changes. Tabular Data Display Press the Esc key to exit place mode. Create a Memristor Current,Voltage vs. Select the Cartesian and then left click on the schematic to place the symbol.

    Component Diagram Cartesian Plot Select tran. Diagram Cartesian Vmr Settings Double click on the tran. I PR1 in the Graph window. Select right axis in the y-Axis: drop-down list. Cartesian I,V vs. Time Plot Settings Click Apply to save the changes. Left click anywhere on the plot window and use the corner grab handles to resize the plot. Component Diagram Cartesian Plot Double click on the tran. Cartesian Pr1 Current Setting Select the tran.

    Select tran. I PR1 tran. Transient Simulation Results You should also checkout the documentation and other examples listed in the Qucs 0.

    How to: Getting Started with LTspice

    However, there is a new free option after the closing of Spectrum Software last year: Micro-Cap You may be thinking: why use another closed-source simulator? The simulator boasts a multipage schematic editor, native robust digital simulation, Monte Carlo analysis, 33, parts in its library, worst-case and smoke analysis, Smith charts, and it can even incorporate spreadsheets.

    Have a look at the brochure and you will see this is a pretty serious piece of software. Models The number of models supported for active devices is impressive and includes some very recent MOSFET models, not just the old standard models.

    It can also export Spice files if you want to use another engine or share designs with other Spice users. There are also quite a few examples provided. As a bonus, we tried it under Wine and it worked well — at least the bit version. The bit one would probably work with a little effort. On a big monitor, you might want to use Winecfg to set a higher DPI setting, although the toolbar icons are fixed in size which is a little inconvenient. Features One nice touch is that you can view a simulation and interactively change component values and watch the results update right away.

    We frequently use Spice when we are too lazy to do the math required to pick an optimal set of values. With this software, you can set ranges for various circuit components, tell the program what you want to optimize, and it will compute the best values for you. The smoke analysis is somewhat unique. The idea is to run a transient analysis and the program determines if any circuit values exceed the maximum value for a component. You get a nice colored graph that tells you how close you are to smoke or, if you have some red bars, what parts will smoke.

    Another neat feature is that you can create very cool 3D plots. This is especially useful if you are stepping parameters or measuring the effect on parameter variation like temperature. One other feature we liked is that the program can output a netlist for printed circuit board programs including Protel, Accel, Orcad, and PADS. Over 18, components in the library have packages available and there is a package editor.

    We wish it would work with KiCAD, although we are pretty sure you could figure out some conversion path from one of the formats available. Why Free? The software was under development since However, we appreciate the free release of this powerful simulator that can give LTSpice a run for its money.

    Learning If you are trying to learn the program, there are some starting instructions for an older version that should get you the basics. We went looking for tutorials and found that [Kiss Analog] just started a set of video tutorials.

    Then again, for just playing around, the Falstad simulator is pretty nice and requires no installation.

    Commercial Circuit Simulator Goes Free

    This change in voltage causes a change of current in the circuit. This is observed as the gradient of the initial current inrush the greater the inductance, the lower the rate of change, the shallower the gradient. After the voltage is applied the motor begins to turn. The faster the motor turns, the greater the back EMF in the coils. This back EMF not only reduces the height of the initial current inrush but in the steady-state means that the current draw is significantly lower than the motor terminal resistance alone would permit.

    This can be proven with a quick calculation from the DC motor datasheet, such as theby taking the Rated Voltage and dividing it by the Typical Terminal Resistance. The peak inrush current is identified as the first stationary point in the plot below marker B.

    Note that the peak inrush current is limited by back EMF, which is a function of the motor speed. Remember that an instant transition between voltages is not physical. In a real application, it can be useful to limit the rise time of the driving signal for just this reason.

    These spikes are why flyback diodes are recommended such as the Schottky flyback diode recommended here. It can be seen that the coil inductance acts to limit the initial current inrush, whereas the back EMF acts to reduce the steady state current. We can model a motor in a stall condition as a sudden large increase in the mechanical equivalent circuit resistance. Determining Rotor Position The voltage at C1 provides the angular position of the rotor in radians.

    Modelling A Vibration Motor We can use this simple DC motor to plot the periodic acceleration of a test sled caused by a vibration motor. By default, LTSpice computes trigonometric functions with arguments in degrees. Thus, the argument in Trace Equation 1 is converted from radians by the multiplication factor of An example of this trace output can be seen in the stall condition model extension here. Dimensional Analysis Of Equations 9 And 11 Using the table in figure 3, we can perform a dimensional analysis of the final equations in order to check their validity.

    Electronic circuit design and simulation software list

    Performing the same analysis on equation Behavioural Extensions To The Model Extensions to the basic DC motor model are presented, with the intention of emulating the behaviour of real-world motors. Additional voltage sources are also included in the mechanical equivalent circuit, including a source to account for the effect of gravity on the eccentric mass.

    An optional load torque voltage source is also included. At this voltage, the current through the motor coils results in a sufficient torque to overcome the inertia and static friction of the system and the rotor begins to turn. This determines the speed at the shaft of the motor.

    some of good samples and projects in the QUCS format

    Additional terms for friction and inertia are included, as well as a voltage source into which a load torque profile can be set. PyCircuit is a package available from a git repository and it has been partly developed by a friend of mine, Joacim Frisk.

    It has an embryo for a gnucap see 7 interface, i. I have only done some rudimentary trials with pycircuit. If I get some time, I will evaluate the tool more I just need a windows machine … or at least try over wine.

    As 5 does, they offer a large variety of free circuit descriptions to be downloaded from their home page. It has the basic simulator options and can handle veriloga code and more. This hurdle and the fact that it is not that well maintained currently or?

    I put it high on the list, though, as it is associated with the gEda flow and is available in e. It is also free and fairly well maintained. It enables me to quite quickly go from a spice-format and run with a free simulator.

    Quite easily, I can kick of a large corner set using an unlimited amount of licenses. As for the other free simulators, it is a bit limited in terms of simulation options does not contain periodic steady-state analyses, etc. At home I use it quite extensively to test different ideas and it can be trimmed to simulate veriloga, etc. Further on, it can be quite easily associated with the Electric layout editor and some of the other freeware tools such as the gEda package.


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