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This is the second video introducing beige bag spice. In this video you will learn how
to put a dependent source circuit and how to do a DC sweep.
The handout corresponding to this video can be found on the instructor's webpage, or in
D2L. The schematic we will be drawing can be found
on page 3 of the handout. You will begin by starting beige bag spice.
Go to start menu. Select all programs, then B2 spice ad version five and select B2 Spice
version five. This brings up a new schematic. Looking at the schematic in the handout, you
see that the circuit consists of a DC source, three resistors, and a current controls voltage
source. Let's start by placing the dc source. Click
on the 'Add part' tab. Click on virtual components, voltage sources and battery. This gives us
the schematic symbol for battery. Place the component by simply left-clicking in the schematic
space. The default value for the voltage of the battery is one volt. Since this is the
value we're looking for you can move on to the next component.
Most schematics you draw will have resistors. Since this is a very common part, there is
a shortcut key for placing them. Press F4. This gives us a generic resistor. Place three
resisters in the schematic. To reorient a
resistor simply right click to rotate it before placing it.
Once you have placed all three resistors, go back and correct the values for all the
components. To change the values you can either double click on the component or on the component
value. For R1 the value should be 2 kilo-ohms. R2 should be 3kilo ohms and R3 should be 5.1kilo
ohms. That component being introduced in this demonstration
is the current controlled voltage source. To place the current controlled voltage source,
and click on the add part tab, virtual components, voltage sources, and current controlled voltage
source. Right click to reorient the voltage source and left click to place it in the schematic.
Now, since this is a controlled source, you need to add the controlling parameter. Further
since this component is current controlled, you need a current meter to control it. The
current meter, or ammeter, is found by clicking the common parts to tab. Select the vertical ammeter. To complete
the setup of the dependent source, double click on the dependent source. In the dialogue
that comes up you can now select the controlling ammeter, in this case AM1. In the handout
up you can see that the gain of the controlled source is to be 10k. Enter 10k into the box
labeled gain in the dialogue box. The last component you need to place, as you
do in every schematic, is the ground. The ground can be selected by pressing F3.
Once all the components are placed, you can wire the circuit. Click the wire tool in the
menu bar or simply press the letter W. Wiring begins when you click on the green dot of
a component's terminal and ends when you double click on the green dot of the terminal you
wish to connect to. Continue this process until all the wires
are placed by clicking once where you want a wire to begin and double clicking where
you want the wire to end. Remember that, when wires cross, if you want them connected you
must click on the crossing point. Otherwise the wires will not connect.
Once the circuit is constructed, you can go on and set up the simulation. To begin, click
on the tests tab. If you look at the handout, you are to sweep the independent dc voltage
source from -100V to 500V in increments of 10V.
Select the sweep DC Bias box. Select the Sweep tab. Select ‘Set up Sweeps’.
Select the voltage source from the list of Part Parameters. Under ‘Parameter Setup’
select Sweep. Enter the Start value of -100V, a step interval
of 10V, and the end value of 500V. Click ‘Accept Changes’. Click OK.
Since you are sweeping parameter, it may be desirable for us to graph the output.
Select the Graph check box. Click ‘Run’.
You see a graph appears showing all the available output parameters. If you want to limit the
number of graphs you have, you can click on the preset graph plots button. If you highlight
everything in the right hand box and click on remove you can then go back and selects
the specific plots that you wish to graph. If you do not know the names of the plots
that you wish to graph you can cancel out and go back to the schematic. Here you can
put voltage probes into the circuit to specify the node voltages that you want graph. To
place a voltage probe, go to Common parts, probes and voltage. Then simply place the
probe on the node that you want graph. Repeat for each node that you want a graph of. Then
click run and you see that the voltages for the nodes that you placed probes at are automatically
graphed. That’s all for now. Thanks for watching
and have a great day.