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RECITATION 7
Problems for this week:
1. Problem 4.35(Page # 336)
2. Exercise 4.20(page # 253)
3. Problem 4.64(Page # 340)
INSTRUCTIONS:
Problem 4.35:
For the circuits shown in Fig P4.35 (a),(c),(e), find the values for the labeled node
voltages and branch currents. Assume  to be very high.
Part (a):
PARTS USED: Q2N3904, R, VDC, GND_EARTH
Step 1: Using Pspice schematics, build the figure given below.
Step 2: Choose the transistor and go to
EDITMODELEdit Instance Model Text.
Change Bf=10000(very high value)
Step 3: Simulate the circuit and measure the voltages V1 and V2 directly from the
schematics.
Step 4: To view the voltages click the voltage display button V on the toolbar and
verify with your hand calculated value.
Part(e):
PARTS USED: Q2N3906, R, VDC, GND_EARTH
Step 1: Using Pspice schematics, build the figure given below.
Step 2: Choose the transistor and go to
EDITMODELEdit Instance Model Text.
Change Bf=10000(very high value)
Step3: Simulate the circuit and note down the measured values.
NOTE: Your measured values will be slightly away from the hand-calculated
values.
EXERCISE 4.20:
Use the circuit given below to find the voltages and current.
HAND CALCULATION:
This problem has been solved in the lecture, you can verify with that.
PROCEDURE:
Step 1: Using schematics draw the circuit given below.
Step 2:Click or choose transistor Q3.Goto
EDIT MODELEdit Instance Model text
Change Bf = 100. (Bf is the spice parameter for )
Step 3: Simulate the circuit and note down the marked voltages VE1, VE2, VE3
and VC2.Verify the results with your hand calculated values.
Step4: Note the currents through all branches. (You can use the Example4.8 (page
#251 as reference for this problem)
Problem 4.64:
Assume  is very large and find the collector current IC, vo1/vi,and vo2/vi.Use
figure p4.64.
PROCEDURE:
Step 1: Using PSPICE schematics draw the given circuit.
Step 2:Goto AnalysisSetupACSweep.
Step 3: Simulate the circuit.
Step 4:Measure the current from the schematics using Current markers.
Step 5: Plot vo1/vi and vo2/vi and check the output with your hand-calculated
values.
Step 6: Go to AnalysisExamine output.
A text window will open. Keep scrolling down till find BIPOLAR JUNCTION
TRANSITORS.
Under that you will various parameters. You can check your GM, IC, and IB etc. from
the output file.
NOTE: Your output file also gives the node voltages and currents.