Free software package allows you to simulate diagrams and tracing printed circuit boards. Creating a scheme in the MultiSim Multisim program examples

PURPOSE OF THE WORK

Studying and receiving work skills in the program Multisim

Job

Examine the principle of building electronic circuits in the program Multisim

General

The organization of the Multisim program interface is presented in Fig. 1. Here is the standard toolbar containing the buttons for the most common functions of the program.

The simulation panel allows you to start, stopping and other simulation functions described below.

The toolbar has hassle for each of the tools used from Multisim database /

The overall design panel shown in Figure 1. Contains a window of a circuit in which the scheme has been placed.

The standard panel contains the following buttons:

The following buttons are located on the toolbar:

And finally, the following elements are shown on the components panel:

Instruments

The Multisim program has a number of virtual devices. These devices are used as well as their real equivalents. Using virtual devices is one of the best and simple ways to study the scheme. These devices can be placed in any level of the circuit or subcircuit, but they are active only now for the circuit or subcircuit on active ingredients.

Virtual devices have two types: the tool icon that you install on your scheme, and, open device, where you install the instrument management method and display on the screen.

The instrument icon shows how the device is associated with the scheme. When the tool is active, a black point inside I / O indicators shows that the device is associated with a branching point.

Adding a device to the scheme:

1. By default, the instrumental instrument panel is displayed on the workspace. If the tool panel is not displayed, press the INSTRUMENTS button. The instrument panel of the Instruments appears on which each button matches one tool.

2. On the Instruments toolbar, press the instrument button you want to use.

3. Move the cursor to the location of the scheme where you want to place the device and click on the mouse button.

The instrument icon and identifier will appear. The instrumental identifier identifies the type of device and its sample. For example, the first device that you post in the diagram will be called "XMM1", the second - "xmm2", and so on.

Note: To change the color of the Instrument icon, click on the mouse button off and select Color From the context menu. Select the desired color and click OK.

Using the device:

1. To view and change the instrument management tools, double-click it. The instrument management window will appear. Make the necessary changes to the settings as well as you would do it on their real equivalents.

Please note that settings must match your scheme. If the settings are incorrect, it can distort the imitation results.

Note: Not all areas of the open device can be changed. A sign in the form of a hand appears if the cursor is on the setting that can change.

2. To "activate" the scheme, click the SIMULATE button on the control panel, and select Run from the pop-up menu that appears. Multisim will begin to imitate the behavior of the circuit and the values \u200b\u200bof the measured parameters at the points to which you connected the device.

While the scheme is activated, you can adjust the tool settings, but you cannot change the circuit, changing the values \u200b\u200bor perform any actions, such as rotating or moving the item.

Creating electrical schemes is a drawing of them on the work field. At the first stage, after starting the program, it is necessary to make the required elements from libraries, and then combine them specified.

To make an element from the library, you must redo the left button on the library. A window will appear with the library components. Then, once climbing the element, you must move the mouse pointer to the working field, after which, clicking the mouse at any point of the working field, you place the element there.

The connection of the elements is carried out as follows: When you hover the mouse pointer to one of the clamps of the element, it will take the type of cross, next to the left mouse button, start moving the mouse pointer. The dotted line will sweep behind it. To make it necessary to move the lines of the line at a specified point, click the left mouse button. When you click the mouse pointer to the free output of the element, a node or conductor (connecting line) and click the left mouse button, the line connecting the elements (conductor) will appear.

Resistance to conductors in Multisim zero. It must be borne in mind that the scheme must necessarily be grounded, and at least one measuring device must be present on the working field. Grounding is connected to any point of the circuit.

When the scheme is collected, and all the necessary measuring instruments are connected, you can start simulation (enable the diagram). The inclusion is carried out in the switch in the upper right corner of the screen. After turning on the scheme, the model starts working. After removing the required data, the scheme must be disabled. Any changes in the scheme are possible only in the disconnected mode.

Development of electrical circuit

As examples to create a circuit circuit diagram (Figure 2.3), Arduino UNO was taken on the ATMEGA328 microprocessor and ChipKit Max32 to PIC32MX795F512.

Figure 2.3 - Concept of development concept.

As mentioned earlier, Intel 8051 is used as a microprocessor. For power it can be used both 5V and 3.3B. The scheme (Figure 2.3) contains an ICSP connector (in-circuit serial programming), it is necessary in order to connect the programmer to the microprocessor to make the programmer. Also, the scheme includes a set of digital and analog outputs, to connect all sorts of sensors. So it includes a quartz generator, which is intended to obtain fixed frequency oscillations with high temperature and time stability, low level of phase noise. Transistors in the chains are used to enhance, generate and transform electrical signals. Capacitors in the chains are used as a filter, which is capable of pretty successfully suppress the RF and HB of interference, voltage ripples and accelerations. Diodes are to be converted to permanent alternating current to constantly, in particular, they are used for rectifiers that are included in the design of the network adapter. The D-SUB connector is widely used to transmit data over the RS-232 serial interface. Standard recommends, but does not oblige the use of D-Sub connectors for these purposes.

Creating a scheme in the Multisim program

The first step in the creation of the electrical circuit in the Multisim program was the selection stage from the library (Figure 2.4) of the required microchrocessor and the setting of its initial parameters.

Figure 2.4 - component selection window.

Intel 8051 was selected as a microprocessor in the DIP-40 housing.

Figure 2.5 - Microprocessor settings window (step 1).

In the first step, the setup (Figure 2.5) indicates the name of the workspace and where it will be located.

Figure 2.6 - Microprocessor setting window (step 2).

Figure 2.7 - Microprocessor setting window (step 3).

In the second step, the setup (Figure 2.6) indicates the type of design of the microprocessor. For more simplicity, a type was selected with the use of an external hex file, which contains a ready-made microprocessor firmware.

In the final steps, the settings (Figure 2.7) indicates whether the finished project will be used or an empty project will be created.

After all the setup steps are completed, the transition to the microprocessor settings is completed. The settings specified the volume of the built-in internal RAM, the built-in external RAM, the volume of the ROM, indicates the clock frequency on which the microprocessor runs.

To make the firmware file, you must go to the "MCU Code Manager" section. Next, the project is selected, which was created when setting up a microprocessor and indicate that for the machine code file for modeling. The MCU Codes Manager window is shown in Figure 2.8.

Figure 2.8 - MCU Code Manager.

After making the firmware, it is checked for its performance and the memory is checked for errors when filling the firmware into a microprocessor (Figure 2.9).

Figure 2.9 - memory view window.

As a layout on which all the schema elements are located, Arduino Uno Shield has been selected, which represents a blank board, which only arranged outputs for connecting sensors.

After creating a layout in the Multisim program, this scheme was translated into the UltiBoard program, to create its 3D model (Figure 2.11) and the location of the elements on the board (Figure 2.12). 3D model shows how our development will look, even before it is made.

Figure 2.12 shows the location of the elements on the printed circuit board. It is necessary to create a template for which the first test samples will be manufactured.

Figure 2.10. - Arduino Uno Shield in Multisim.

Figure 2.11 - 3D ARDUINO UNO SHIELD model in UltiBoard.

Figure 2.12 - Arduino Uno Shield in UltiBoard

Figure 2.13 - Finished development in the Multisim program.

After creating a scheme in the Multisim program, it was broadcast to the UltIBoard program, to create a 3D development model (Figure 2.14), the location of the elements on the printed circuit board and wiring the elements by printed circuit board (Figure 2.15).

Figure 2.14 - 3D model of finished development in the UltiBoard program.

Figure 2.15 - Printing Board of Finished Development in the UltiBoard program.

All let the development of the development can be submitted to the block diagram that is depicted in Figure 2.16.

Figure 2.16 - Let the development of development.

Due to the wide development of computing devices, the task of calculating and modeling the electrical schemes is noticeably simplified. The most appropriate software for these goals is the National Instruments Product - MultiSim (Electronic Workbench).

In this article, consider the simplest examples of modeling of electrical circuits using Multisim.

So, we have Multisim 12 is the latest version at the time of writing the article. Let's open the program and create a new file using a Ctrl + N combination.

After creating a file, the work area opens before us. In fact, the Multisim worksheet is a field for collecting the desired scheme from the existing elements, and their choice, believe the largest.

By the way briefly about the elements. All default groups are located on the top panel. When you click on any group, the context window opens in front of you in which you choose the element you are interested in.

By default, the base of the elements is Master Database. The components contained in it are divided into groups.

List briefly the content of groups.

SOURCES contains power supplies, grounding.

Basic - resistors, condensers, inductors, etc.

Diodes - contains various types of diodes.

Transistors - contains various types of transistors.

Analog - Contains all types of amplifiers: operational, differential, inverting, etc.

TTL - contains elements of transistor-transistor logic

CMOS - contains elements of CMOS logic.

MCU Module - Multi-Record Managing Module.

Advanced_Peripherals - Plugable External Devices.

Misc Digital - various digital devices.

Mixed - Combined Components

Indicators - Contains measuring instruments, etc.

The simulation panel is also nothing complicated, as on any reproducing device, the start buttons, pauses, stops are depicted. The remaining buttons are needed for modeling in step-by-step mode.

On the instrument panel there are various measuring instruments (top down) - multimeter, functional generator, wattmeter, oscilloscope, plotter baud, frequency meter, word generator, logical converter, logical analyzer, distortion analyzer, table multimeter.

So, running the functionality of the program, let's turn to practice.

Example 1.

To begin with, we collect a simple scheme, for this we need a DC source (DC-POWER) and a pair of resistors (resistor).

Suppose we need to determine the current in the unbranched part, the voltage on the first resistor and the power on the second resistor. For these purposes, we will need two multimeters and wattmeter. The first multimeter switch to the ammeter mode, the second - voltmeter, both for a constant voltage. The current winding of the wattmeter is connected to the second branch sequentially, the voltage winding parallel to the second resistor.

There is one feature of modeling in Multisim - a grounding must be present in the diagram, so one pole of the source we are ground.

After the scheme is collected by pressing the simulation start and see the instrument readings.

Check the correctness of the testimony (just in case \u003d)) according to the law

The instrument readings turned out to be correct, go to the next example.

Example 2.

We collect an amplifier on a bipolar transistor according to a scheme with a common emitter. As a source of input signal, use a function generator (Function Generator). In the FG settings, we select a sinusoidal signal amplitude of 0.1 V, with a frequency of 18.2 kHz.

Using an oscilloscope (Oscilloscope), we will remove the oscillograms of the input and output signals, for this we will need to use both channels.

To check the correctness of the oscilloscope readings, we put on the input and to the output by the multimeter, switching them to the wailmeter mode.

Run the scheme and open each device with a double click.

Voltmeter readings coincide with the oscilloscope readings, if you know that the voltmeter shows the active voltage value, to obtain which it is necessary to divide the amplitude value to the root of two.

Example 3.

With the help of logical elements 2 and not collect a multivibrator that creates rectangular pulses of the required frequency. To measure the pulse frequency, we use the frequency meter (Frequency Counter), and check its testimony using an oscilloscope.

So, let's say we set out the frequency of 5 kHz, picked up the required condenser values \u200b\u200band resistors experienced. Run the scheme and check that the frequency meter shows approximately 5 kHz. On the oscillogram, we note the period of the impulse, which in our case is 199.8 μs. Then the frequency is equal

We reviewed only a small part of all possible program functions. In principle, Multisim will be useful to both students, to solve problems for electrical engineering and electronics and teachers for scientific activities, etc.

We hope this article has been useful for you. Thanks for attention!