A program for emulating circuits in Russian. Qucs is an open-source CAD software for simulating electronic circuits. Conclusions on the program "Beginnings of Electronics"

Qucs, also known as Quite Universal Circuit Simulator, was designed as an affordable electronic circuit and circuit simulator that has graphical interface and based on open source code. The program supports all kinds of circuit simulation, such as DC, AC, S-parameters, harmonic balance analysis, noise analysis and so on. The simulation results can be viewed on the presentation page or the program window.

Qucsator, server part programs is a simulator command line which manages the list of networks specific format I / O dataset Qucs. It was created by default to work with the Qucs project, but it can be used with other applications as well. The program has support for exporting images of symbols with Verilog-A files to C ++ code, support for direct communication with Verilog-HDL symbols and VHDL subchains. Latest Versions Qucs have a GNU / Octave interface.

Key features and functions

• support for the syntax of Verilog-HDL and Verilog-A in text documents;
• support for exporting C ++ code;
• support for equations for Verilog-HDL and VHDL subchains;
• pre-compiled VHDL modules and libraries;
• support for all modern components;
• open source allows you to develop extensions;
• customizable and extensible interface;
• built-in file converter;
• the ability to download additional interface languages.

Simulator electronic circuits in Russian Is an ordinary SPICE simulator called TINA-TI with an easy-to-understand graphical interface. This program works without any limit on the number of devices used, easily handles comprehensive work. Perfectly matches the imitation of the behavioral response of a variety of analog circuits, as well as switching power supplies. Using TINA-TI, you can easily design a circuit of any degree of complexity, connect earlier created fragments, explore and recognize the circuit's quality indicators.

All the presented elements available simulator of electronic circuits in Russian TINA-TI, dispersed distributed into six types: passive components, switch keys, semiconductor devices, measuring devices, miniature device models increased complexity... Additionally this software includes many exemplary samples.

Electronic circuit simulator compiled in Russian, so with its help you can easily master drawing and correction schematic diagrams... The process of creating a circuit itself is not difficult and after this operation is completed, the simulation stage begins. The program can perform the following types of research: assessment of permanent and alternating current... V this analysis includes - calculation of key stresses, plotting the final result, determining intermediate parameters and testing temperature.

Next comes the study of intermediate processes, noise distortions. Conditionality from the research category, training program forms the final total in the form graphic images or tables. Before starting the simulation, TINA-TI checks the circuit for the presence or absence of errors. When any deviations are found, then all the flaws will be shown in a separate window in the form of a list. If you click with the mouse on the inscription with an error not recognized by the simulator, then the detail or part of the drawing will be marked with marker symbols.

Additionally, TINA-TI can measure and test various signals. To implement this type of research, there are virtual devices for this: a digital multimeter, an oscilloscope, a signal tester, a source of periodic signals, and a recorder. All simulation devices available in the software match the actual measuring devices as closely as possible. They can be virtually connected anywhere in the circuit under study. All informational data received by conventional devices are stored in the computer memory.

There are not that many open-source CAD systems out there at the moment. However, there are some pretty decent products in the electronics CAD (EDA). This post will focus on Open Source Electronic Circuit Modeler source code... Qucs is written in C ++ using the Qt4 framework. Qucs is cross-platform and released for Linux, Windows and MacOS.

The development of this CAD system began in 2004 by the Germans Michael Margraf and Stefan Jahn (currently not active). Qucs is currently being developed by an international team, which includes me. The project leaders are Frans Schreuder and Guilherme Torri. Under the cut it will be told about key opportunities our circuit modeler, its advantages and disadvantages compared to analogues.

The main window of the program is shown in the screenshot. There, a resonant amplifier on a field-effect transistor was modeled and oscillograms of the voltage at the input and output and also the frequency response were obtained.

As you can see, the interface is intuitive. The central part of the window is occupied by the actual circuit being modeled. Components are placed on the diagram using the drag-and-drop method from the left side of the window. Simulation views and equations are also special components. The principles of editing circuits are described in more detail in the documentation for the program.

The Qucs schema file format is based on XML and comes with documentation. Therefore the Qucs schema can be easily generated third party programs... This allows you to create circuit synthesis software that is an extension of Qucs. Proprietary software typically uses binary formats.

Let's list the main components available in Qucs:

1. Passive RCL Components
2. Diodes
3. Bipolar transistors
4. Field effect transistors (JFET, MOSFET, MESFET and microwave transistors)
5. Ideal op amps
6. Coaxial and microstrip lines
7. Library components: transistors, diodes and microcircuits
8. File components: subcircuits, spice subcircuits, Verilog components

The component library uses proprietary format based on XML. However, it is possible to import existing Spice-based component libraries (provided in the electronic component datasheets).

Supported the following types modeling:

1. DC operating point simulation
2. AC Simulation in the Frequency Domain
3. Time Domain Transient Simulation
4. Modeling S-parameters
5. Parametric Analysis

Simulation results can be exported to Octave / Matlab and post-processed there.

Qucs is based on a newly developed schematic simulation engine. A distinctive feature of this engine is the built-in ability to simulate S-parameters and VSWR, which is important for the analysis of RF circuits. Qucs can convert S-parameters to Y- and Z-parameters.

The screenshots show an example of modeling the S-parameters of a high-frequency broadband amplifier.

So, distinctive feature Qucs is the ability to analyze complex frequency response (CFC), complex plane graphs and Smith charts, analyze complex impedances and S-parameters. These capabilities are absent in proprietary MicroCAP and MultiSim systems, and here Qucs even outperforms commercial software and provides results that are unattainable for electronic circuit simulators based on Spice.

The disadvantage of Qucs is the small amount of library components... But this drawback is not an obstacle to use, since Qucs is compatible with the Spice format in which models of electronic components are shown in datasheets. Also, the modeler is slower than comparable Spice-compatible modelers (such as MicroCAP (proprietary) or Ngspice (open-source)).

We are currently working on the ability to provide the user with a choice of engine for modeling the circuit. It will be possible to use the built-in Qucs engine, Ngspice (a spice-compatible console modeler similar to PSpice) or Xyce (a parallel compute modeler via OpenMPI)

Now let's take a look at the list of innovations in the recent release of Qucs 0.0.18 promising directions in the development of Qucs:

1. Improved compatibility with Verilog
2. Porting of the interface to Qt4 continues
3. Implemented a list of recent open documents in the main menu.
4. Export of charts, diagrams to raster and vector formats is implemented: PNG, JPEG, PDF, EPS, SVG, PDF + LaTeX. This function is useful when preparing articles and reports containing simulation results.
5. Ability to open a schematic document from a future version of the program.
6. Fixed bugs related to the freezing of the modeler under certain conditions.
7. A system for the synthesis of active filters for Qucs is under development (expected in version 0.0.19)
8. The development of interfacing with other open-source engines for modeling electronic circuits (

11. Droid Tesla

Droid Tesla is a simple and powerful SPICE electrical circuit simulator. In addition to radio components, various current and voltage sources are supported, as well as basic measuring instruments, incl. virtual oscilloscope. Droid Tesla allows you to emulate the following current / voltage sources: source direct current and voltage; sources of alternating current and voltage; CCCS, CCVS, VCCS, VCVS - controlled current and voltage sources; generator of triangular impulses; generator of rectangular pulses.
Supported emulation of the following electronic components: resistor; capacitor; inductance; transformer; potentiometer; incandescent lamp; ideal operational amplifier; bipolar and MOSFET transistors; diode, LED and zener diode; switches; digital logic elements: AND, NAND, OR, NOR, NOT, XOR, XNOR; triggers; 555 timer; relay; 7-segment indicator, etc. The following are supported as measuring devices in Droid Tesla: AC / DC ammeter and voltmeter; 2-channel oscilloscope. Of the interesting features of the software, one can note the visualization of the current flow (to enable the display, you must tick the appropriate checkbox in the program settings: Settings -> Animations -> Animation of current flow). After that, when the circuit simulation is turned on, the current flow can be visually observed. The only thing is that in this mode the operation of the circuit is greatly slowed down and the processor resources are consumed to a greater extent.