ENGINEERING-43
Superposition
Lab-06
Lab Data Sheet – ENGR-43 Lab-06
Lab Logistics
Experimenter: H. Nguyen and L. J. Omictin
Recorder: L. J. Omictin and H. Nguyen
Date: 17March2010
Equipment Used (maker, model, and serial no. if available)
Tektronix CDM250 3½-Digit Digital MultiMeter (DMM), S/N = IW12844
Tektronix PS280 DC Voltage/Power Supply, S/N = TW52716
Directions
1. Note that in this and ALL OTHER Laboratory Exercises ENGINEERING UNITS must
accompany ALL Data-Entries and Calculated-Quantities
2. Check out a DMM and Power/Probe Leads for the Power-Supply and DMM
3. Go to the side counter, collect resistors, “bread board”, and leads required to construct the
circuit shown in Figure 1.
4. Table I, Table III, and Table III.
 Deactivate a power supply by removing its leads and replacing the supply with a short
to GND. See Figure-2 and Figure-3
 Take care to use the Proper POLARITY When Measuring the Ij and VRj
o Use the PASSIVE SIGN CONVENTION for consistent measurements
 Always ASSUME that currents flow in the direction shown in Figure 1
5. Return all lab hardware to the “as-found” condition
6. Show mathematically how the Vs1-Only and Vs2-Only currents and potentials
SUPERPOSE (add or subtract) to yield the BOTH-Active values.
 Draw Circuit Diagrams for the three cases and complete Table IV
o Perform calculations using the measured supply-potentials and resistance
values.
 Attach the circuit diagrams to your lab sheet for full credit
© Bruce Mayer, PE • Chabot College • 282217135 • Page 1
Figure 1 • A Superposed Circuit. Vs1 = 9.00 Vdc. Vs2 = 12.00 Vdc. R1 = 0.8-1.6 kΩ (1 kΩ
nominal). R2 = 2.7-4 kΩ (3kΩ nominal), R3 = 1.5-3 kΩ (2 kΩ nominal). Approximate
R1:R2:R3 value-ratio = 1:3:2
NOTE
The “+” Side of Vs1 and Vs2 MUST always:
 Be Separated by at least one resistor
 Have a RESISTIVE path to GND
Table I – Resistance Measurements
Value Determination
R1
R2
R3
ColorCode
15E2 Ω, ±10%
33E2 Ω, ±10%
27E2 Ω, ±5%
Measured
1.610 kΩ
3.48 kΩ
2.80 kΩ
Table II – Voltage Supply Measurements
Value Determination
Vs1
Vs2
Nominal
9.0000 V
12.0000 V
Measured
8.98 V
12.08 V
© Bruce Mayer, PE • Chabot College • 282217135 • Page 2
Figure 2 • DEACTIVATE source Vs2 by
REPLACING it with a WIRE which
ensures that the POTENTIAL ACROSS
Vs2 is now ZERO.
Figure 3 • DEACTIVATE source Vs1 by
REPLACING it with a WIRE which
ensures that the POTENTIAL ACROSS
Vs1 is now ZERO.
Table III – MEASURED Currents and Potentials
Active Vs
VR1 (V)
VR2 (V)
VR3 (V)
I1 (mA)
I2 (mA)
I3 (mA)
Vs1 ONLY
4.58
−4.40
4.41
2.82
−1.234
1.529
Vs2 ONLY
−2.74
9.34
2.75
−1.647
2.68
0.954
BOTH
1.841
4.94
7.15
1.097
1.383
2.54
Calc %
0.05432%
0.00%
−0.1399%
−6.928%
−4.555%
2.2441%

% = 100[XBOTH - (Xj)]/XBOTH
o Where Xj  either of VRj or Ij
Table IV – CALCULATED Currents and Potentials
Calculate using the DMM measured supply-potentials and resistance values.
 Draw Circuit Diagrams, and show the associated calculations
o Attach the Circuit-Diagrams and Calculations to the Lab Sheet to receive full
credit
Active Vs
VR1 (V)
VR2 (V)
VR3 (V)
I1 (mA)
I2 (mA)
I3 (mA)
Vs1 ONLY
4.57295
−4.40705
4.40705
2.84034
−1.26639
1.57395
Vs2 ONLY
−2.74274
9.33726
2.74274
−1.70357
2.68312
0.97955
BOTH
1.83021
4.93055
7.14979
1.3677
1.41673
2.5535
© Bruce Mayer, PE • Chabot College • 282217135 • Page 3
© Bruce Mayer, PE • Chabot College • 282217135 • Page 4
© Bruce Mayer, PE • Chabot College • 282217135 • Page 5
© Bruce Mayer, PE • Chabot College • 282217135 • Page 6
Print Date/Time = 29-May-16/03:59
© Bruce Mayer, PE • Chabot College • 282217135 • Page 7