The components of which are simulated in the program Multisim schematic is divided into two categories. The first category is real, or commercially available components, and the other is virtual. The values of the parameters of industrial components can't be changed and must match the settings made by the industry standards. The values of the parameters of the virtual components can take arbitrary values. Graphic symbols of industrial components in the program are colored in blue, and virtual ? black.
Virtual components are used at the stage of circuit simulation, when the values of their parameters, which are defined in the result of calculations may be exact value. Virtual components can also be some idealized devices and components form BASIC_VIRTUAL, components constraints RATED_VIRTUAL etc. The components of the form RATED_VIRTUAL you can assign additional parameters, which include for example resistors, the maximum allowable power and time modeling the process of failure of the resistor if exceeded, the dissipated power them. If in the process of modeling the power produced by the resistor will be greater than assigned, the external view of the resistor after the set time will look ?burned out?.
To move the components from their libraries in the workspace main window is used a number of ways of actions. Often used a method wherein the use of a directly bar components of the program. This panel is located at the top of the main window under the Windows toolbar (see fig.1.1).
A list of the libraries panel components program Multisim 10.1.1 from left to right are given below.
1. EDS (DC and AC, single and three phase, special sources, ground).
15. Electromechanical components (single-phase and three-phase motors, touch switches, switches witch installation time, etc.).
In addition to these libraries, on the Panel component of the program are the controls to insert the hierarchical blocks and the application of tires.
If you select any of the libraries by clicking the left mouse button (LMB) when the cursor is located on the select library window appears Select component, which in the case of selecting a resistor with a nominal resistance value 1 kOhn in the expanded view shown in fig. 1.2.
In the upper left corner of this window are drop-down lists the Database and Section / Collection, which include selectable components. In the Database list have Basic, Corporate and Individual basis, and in the Section list / Collection is either a list of component libraries or the component list of the selected library. In the middle of the window Selection component is a list of selected components in libraries, which can be represented by a list of nominal values of the basic
Fig. 1.2. The window is the component Selection if you select a resistor with a nominal resistance value 1 kOhm
parameters of a values of the basic parameter of a component of the industrial designations of its type or names. To the right of the named fields contains the fields Symbol, Function, or component Type, and Tolerance (for components RESISTOR, CAPACITOR, etc.), the Manufacturer, the Manufacturer of the chassis and the Link. At the top right of the window Selection component is a group of buttons that allows you to accept the choice of the component (O?K), close the window to continue the search, cause the report Window to bring up a new window Report data by model or call for help.
After clicking LMB on the select button component the symbol begins to move with the mouse cursor as long as the second click will not determine the location of the component in the workspace of the main window.
To change the orientation of the installed component or use the item Editor in the Main menu, or shortcut: Alt + X ? to turn horizontally, Alt + Y to turn it vertically, Ctrl + R ? rotate clockwise Ctrl + Shift + R ? rotate counter-clockwise. For this purpose it is possible to use the context menu. To change the orientation, first allocate the required component.
After the required component is installed and oriented, you can change its settings or replace it with another if its properties do not meet the required. To do this, double click LMB on the component to invoke its properties window. In this case, the fields in the window that appears possible on the relevant tabs to change the label, to contribute in the fields of its properties, edit component properties directly in his library. If you want to change the properties of the industrial component, it must first be removed from the work fields, and then add the new one with the desired parameters. Therefore for the simulation it is advisable to use virtual components, as their parameters can be edited directly in the window that appears.
In addition to the above functions, the program Multisim 10.1.1 allows you to model a schema in advance, as component defects. This function can be useful in the learning process of students in several other cases. To assign a defect on the corresponding tab of the properties window of the component. For example, a resistor can be marked four of his condition:
1) No fault;
2) Open ? assigned infinitely large resistance;
3) SK ? assigned resistance zero;
4) Leak ? appointed resistance connected in parallel to the resistor in the box below this property if an open circuit in the resistor of the simulated circuit.