EEE 292 Electronic Circuit and Devices
EXPERIMENT 3
EEE 292 Electronic Circuit and Devices
EXPERIMENT 3
VOLTAGE & CURRENT DIVIDER
3.1
Objectives:
Voltage Divider in No-load Operation:
− Measurement of the voltage ratios on a voltage divider in no-load operation.
− Voltage divider Formula.
Voltage Divider Under Load:
− Measurement of voltage ratios on a voltage divider under load.
Current Divider:
− Current Division by Parallel Connected Resistors.
− Curren Division Formula
3.2
Equipment and Materials
Please record any problem if exists any while performing the experiment, and its way of
occurrence in the allocated space of this table in detail. You can also write the difficulties you
are confronted with when using the equipment, and your suggestions and critics related with
the equipment you used.
Figure 3.1 Measurement of the component voltages on a voltage divider.
Table 3.2 Data for Experiment 3.4.1
R1 (Ω)
R2 (Ω)
25
175
50
150
75
125
100
100
125
75
150
50
175
25
V1 (Ω)
V2 (Ω)
R1 / R2
V1 / V2
3.3 Preliminary Work
3.4 Experimental Procedure and Records
3.4.1 Voltage Divider in No-load Operation
i)
ii)
iii)
iv)
v)
vi)
Assemble the circuit as shown in Fig. 3.1. Make sure that the polarities of the voltage
source and the measurement instruments are correct, and that the correct measurement
ranges have been selected.
Set the input voltage VE to 10 V. Measure the component voltages V1 and V2
according to changing R1 and R2 and record these in Table 3.2.
Now assemble the circuit as in Fig. 3.2. Measure the component voltages V1 and V2
for 7 different potentiometer settings and record these in Table 3.3.
For example, say the potentiometer is set to 45%, the increment is 5% and the key is
"R". You press "R", and the setting drops to 40%. You press "R" again, and it drops to
35%. You press SHIFT and "R", and the setting rises to 40%.
Plot the measured results listed in Table 3.2 on Figure 3.3.
Plot the measured results listed in Table 3.3 on Figure 3.4.
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Figure 3.3 Voltage / resistance graph of a divider consisting of two resistors for various
resistance combinations.
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EEE 292 Electronic Circuit and Devices
EXPERIMENT 3
EEE 292 Electronic Circuit and Devices
EXPERIMENT 3
3.4.2 Voltage Divider Under Load
i)
ii)
iii)
iv)
v)
Figure 3.2 Measurement of component voltages on a voltage divider consisting of a
potentiometer.
Table 3.3
Potentiometer Adjustment
%10
%20
%30
%40
%50
%60
%70
%80
%90
%100
V1 (V )
Assemble circuit as shown in Figure 3.5. But, without load resistor RL Take care that
the polarity of the power supply and multimeters is correct, and that the correct
measurement range has been selected.
Set the input voltage VE to 10 V. Measure the component voltages V1 and V2 for 7
different potentiometer settings and record these measurements in Table 3.4. Each
time adjust the input voltage to 10 V.
Repeat the measurements with a load resistor RL=1 kΩ.
Repeat the measurements with a load resistor RL=50 Ω..
Plot the relationship between the voltage V2 as measured at the potentiometer and the
potentiometer setting P for the constant load resistor RL to Figure 3.6.
V2 (V )
Figure 3.5 Measurement of component voltage ratios on a voltage divider under load.
Table 3.4 Data for the Experiment 3.4.2
RL = 1 kΩ
RL = 50 Ω
Pot.
V1 (V)
V2 (V)
Pot.
V1 (V) V2 (V)
%10
%10
%20
%20
%30
%30
%40
%40
%50
%50
%60
%60
%70
%70
%80
%80
%90
%90
%100
%100
Figure 3.4 Voltage / resistance graph of a voltage divider consisting of a potentiometer, for
various potentiometer settings.
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EEE 292 Electronic Circuit and Devices
EXPERIMENT 3
EEE 292 Electronic Circuit and Devices
EXPERIMENT 3
Figure 3.8 Current Divider
Table 3.6 For Table Figure 3.8
I
I1
I2
I3
10 A
Figure 3.6 Setting characteristics of a voltage divider under load at various load
resistance values
3.4.3 Voltage Divider in No-load Operation
i)
ii)
Assemble the circuit as shown in Fig. 4.1. Make sure that the polarities of the voltage
source and the measurement instruments are correct, and that the correct measurement
ranges have been selected.
Set the input voltage I current source to 10 A. Measure the component current I1 and I2
according to changing R1 and R2 and record these in Table 4.2.
3.5 Results and Discussions
1) Answer the following questions by using the data of Experiment 3.4.1.
i) What is the relationship between the total voltage VS and the component voltages
V1 and V2 ?
ii) How do the resistance values relate to the corresponding voltages?
iii) Consider 100 Ω resistor for both Figures 3.7 and 3.8, discuss the current of both
circuit over the 100 Ω resistors.
iv) Using circuit analysis methods and calculate I1 and I2 currents for Figure 3.7.
v) Using circuit analysis methods and calculate I1, I2and I3 currents for Figure 3.8.
Figure 3.7 Current Divider
Table 3.5 For Figure 3.7
I
I1
I2
10 A
iii)
Now assemble the circuit as in Fig. 4.3. Measure the component voltages I1, I2 and I3
for different Resistor values R1, R2 and R3 Table 4.4.
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