boylistad

122 ⏐⏐⏐ OHM’S LAW, POWER, AND ENERGY
Electronics Workbench (EWB)
V
I R
For comparison purposes, Electronics Workbench will be used to analyze
the circuit in Fig. 4.29. Although there are differences between
PSpice and EWB, such as the initiation process, constructing the networks,
making the measurements, and setting up the simulation procedure,
there are sufficient similarities between the two approaches to
make it easier to learn one if you are already familiar with the other.
The similarities will be obvious only if you make an attempt to learn
both. One of the major differences between the two is the option to use
actual instruments in EWB to make the measurements—a positive trait
in preparation for the laboratory experience. However, in EWB you
may not find the extensive list of options available with PSpice. In general,
however, both software packages are well prepared to take us
through the types of analyses to be encountered in this text.
When the Multisim 2001 icon is selected from the opening window,
a screen will appear with the heading Multisim-Circuit 1. A menu bar
appears across the top of the screen, with one toolbar below the menu
bar and one to each side of the screen. The toolbars appearing can be
controlled by the sequence View-Toolbars followed by a selection of
which toolbars you want to appear. For the analysis of this text, all the
toolbars were selected. For the placement of components, View-Show
Grid was selected so that a grid would appear on the screen. As you
place an element, it will automatically be placed in a relationship specific
to the grid structure.
Now to build the circuit of Fig. 4.29. First take the cursor and place
it on the battery symbol at the top of the component toolbar at the left
of the screen. One left click of the mouse, and a list of sources will
appear. Place the cursor on any one of the sources, and text will appear
on the screen defining the type of source. Placing the cursor on the third
key pad down will result in DC VOLTAGE SOURCE. Left-click
again, and the battery symbol will appear on the screen next to the location
of the cursor. Move the cursor to the desired location, and with a
single left click of the mouse the battery symbol can be set in place.
The operation is complete. If you want to delete the source, simply
click on the symbol again with a left click of the mouse to create four
small squares around the source. These squares indicate that the source
is in the active mode and can be operated on. If you want to delete it,
simply click on the Delete key or select the scissor key pad on the top
toolbar. If you want to modify the source, perform a right click of the
mouse outside the four small squares, and you get one list. Perform the
right click within the four squares, and you have a different set of
options. At any time, if you want to remove the active state, simply perform
a left click anywhere on the screen. If you want to move the
source, simply click on the source symbol to create the four squares, but
do not release the clicker. Hold it down and drag the source to the preferred
location. When the source is in place, release the clicker, and one
more click will remove the active state. To remove the SOURCES toolbar,
simply click on the X in the top right corner of the toolbar.
The next key down from the source key that looks like a resistor
controls the display of the Basic passive components of a network.
Click once on the symbol, and two columns of components will
appear. From now on, whenever possible, the word click will imply a
left click of the mouse. The need for a right click will continue to be
spelled out.