Download Electronic Circuits and Devices: ELEE 3455

ECE 3355 – ELECTRONICS
HOMEWORK #11
Extra Problems E11.1, E11.2, E11.3, E11.4, E11.5: These problems are shown
below and on the next pages.
E11.1. The schematic symbol for a Giambulator is shown in Figure 1. Two
characteristic curves for this device are shown in Figure 2 and Figure 3. Find a
model that could be used to predict the behavior of a Giambulator that has been
biased into Region 1, for small signals. Draw the model, labeling all components
with their numerical values, and labeling terminals a, b, and c.
iB [mA]
a
iC =
4[mA]
iC =
3[mA]
iC =
2[mA]
iC =
1[mA]
Region 1
20
iA
10
b
iB
iC
5
c
Figure 1
10
Figure 2
15
iC
[mA]
4
Region 1
2
2
4
Figure 3
6
8
vAC
10 [V]
20
vAB
[V]
25
Problem E11.2
A device called a davistor has three terminals called a, b, and c.
E 11.2 The device has the schematic symbol shown in Figure 1. Reference
polarities for the currents in this device are shown in Figure 1. The device obeys
the characteristic curves shown in Figures 2 and 3. Find a model that could be
used for this device for signals, valid for when the device has been biased in to the
region marked the “linear region”. Explain your answer using complete sentences.
E11.3 A new device, known as a Barcelonor, has the schematic symbol as shown
in Figure 1. Using the polarities defined in this figure, a characteristic curve for
this device is plotted in Figure 2.
Two identical versions of this Barcelonor are inserted in the circuit shown in
Figure 3. Find VX.
Show your work. State your guesses, and test them explicitly.
iB, in [mA]
+
20
10
iB
vB
-10
10
-5
5
-10
-20
-
Figure 2
Figure 1
+15[V]
2.2[k]
1[k]
VX
-15[V]
47[k]
Figure 3
vB, in [V]
E11.4 A piecewise-linear diode model can be used to model a diode that has been
connected to a device. The device is linear. The diode can be modeled using a
piecewise-linear model with Vf = 0.7[V], rd = 100[], and Is = 1[mA].
a) Assume that the device has a Thévenin equivalent resistance that is positive.
How many different solutions for the diode current can there be in this case?
b) Assume that the device has a Thévenin equivalent resistance that is
negative. How many different solutions for the diode current can there be in
this case?
Explain your answers to both parts of the problem, using diagrams, plots, and
complete sentences.
E11.5 The characteristic curve for a device known as a Shadractor is shown in
Figure 1. The definitions for the polarities for the current and voltage are given in
Figure 2.
a) Find a circuit model that would be appropriate for use in the range
7[mA] < iA < 10[mA]. Draw the model, labeling terminals b and c.
b) Find a model that would be appropriate for signals, for IA = -8[mA]. Draw the
model, labeling terminals b and c.
vA, in [V]
6
3
-10
10
-5
5
-3
-6
Figure 1
b
+
Device v
A
iA
Figure 2
c
-
iA, in [mA]