Individual Assignment ECA (simulation) - Wan Hazirah

BEF12403
ELECTRIC CIRCUIT ANALYSIS 1

SIMULATION OF VOLTAGE DIVIDER CIRCUIT

NAME: WAN HAZIRAH BINTI WAN OMAR
MATRIC NO:AE160013

LECTURER’S NAME: DR. AFANDI BIN AHMAD

Figure 1 and Figure 2 shows voltage divider with five resistor series and parallel
combinations respectively while Table 1 shows five (5) different resistors combination.

Figure 1: Voltage divider with five resistor series combinations

Figure 2: Voltage divider with five resistor parallel combinations

Table 1: Five (5) different resistors combination.

Resistors Resistance value (Ω)
R1 6k
R2 0.6k
R3
R4 0.06k
R5 150
60

Calculation

A) Series Circuit

Based on the circuit shown in Figure 1 with resistance value as shown in Table 1,
the calculations are as follows:

RT = R1 + R2 + R3 + R4 + R5
= 6k + 0.6k + 0.06k + 150 + 60
= 6870 Ω

IT = VS/RT
= 15/6870
= 2.18 mA

VR1 = [R1/ (R1 + R2 + R3 + R4 + R5)] × [VS]
= [6k/ (6k + 0.6k +0.06k + 150 + 60)] × [15]
= 13.1V

VR2 = [R2 / (R1 + R2 + R3 + R4 + R5)] × [VS]
= [0.6k / (6k + 0.6k +0.06k + 150 + 60)] × [15]
= 1.31V

VR3 = [R3 / (R1 + R2 + R3 + R4 + R5)] × [VS]
= [0.06k / (6k + 0.6k +0.06k + 150 + 60)] × [15]
= 0.13V

VR4 = [R4/ (R1 + R2 + R3 + R4 + R5)] × [VS]
= [150 / (6k + 0.6k +0.06k + 150 + 60)] × [15]
= 0.33V

VR5 = [R5/ (R1 + R2 + R3 + R4 + R5)] × [VS]
= [60 / (6k + 0.6k +0.06k + 150 + 60)] × [15]
= 0.13V

B) Parallel Circuit

Based on the circuit shown in Figure 2 with resistance value as shown in Table 1,
the calculations are as follows:

1/RT = 1/R1 + 1/R2 + 1/R3 + 1/R4 + 1/R5
= 1/6k + 1/0.6k + 1/0.06k + 1/150 + 1/60
= 251/6000

RT = 6000/251
= 23.904 Ω

IT = VS / RT
= 15/ 23.904
= 0.628 A

1/RA = 1/R2 + 1/R3 + 1/R4 + 1/R5
= 1/0.6k + 1/0.06k + 1/150 + 1/60
= 1/24

RA = 24 Ω

IR1 = [RA / (R1 + RA)] × [IT]
= [24/ (6k + 24)] × [0.628]
= 2.502mA

IRA = IT - IR1
= 0.62 - 2.502m
= 0.617A

1/RB = 1/R3 + 1/R4 + 1/R5
= 1/0.06k + 1/150 + 1/60
= 1/25

RB = 25 Ω

IR2 = [RB / (R2 + RB)] × [IRA]
= [25/ (0.6k + 25)] × [0.617]
= 0.025A

IRB = IRA- IR2
= 0.617 - 0.025
= 0.592A

1/RC = 1/R4 + 1/R5
= 1/150 + 1/60
= 7/300

RC = 300/7
= 42.857Ω

IR3 = [RC / (R3 + RC)] × [IRB]
= [42.857/ (0.06k + 42.857)] × [0.592]
= 0.247A

IRC = IRB - IR3
= 0.592 - 0.247
= 0.345A

IR4 = [R5 / (R4 + R5)] × [IRC]
= [60/ (150 + 60)] × [0.345]
= 0.099A

IR5 = IRC - IR4
= 0.345 - 0.099
= 0.246A

VR1 = IR1 × R1
= 2.502m × 6k
= 15.01V

VR2 = IR2 × R2
= 0.025 × 0.6k
= 15.0V

VR3 = IR3 × R3
= 0.247 × 0.06k
= 14.82V

VR4 = IR4 × R4
= 0.099 × 150
= 14.85V

VR5 = IR5 × R5
= 0.246 × 60
= 14.76V

Simulation
Figure 3 shows the simulation for the circuit in Figure 1 while Figure 4 shows the
simulation for the circuit in Figure 2.

Figure 3: Simulation for the circuit in Figure 1

Figure 4: Simulation for the circuit in Figure 2

Discussion

A) Series Circuit

Table 2 shows the comparison between the value of current and voltage across the
resistors obtained by using Proteus Software and manual calculation for the circuit in
Figure 1.

Table 2: The Comparison between the value of current and voltage across the
resistors obtained by using Proteus Software and manual calculation for the circuit in

Figure 1.

No Resistance, R (Ω) Current, I (mA) Voltage, V (V)
Proteus Manual Proteus Manual

Software Calculation Software Calculation

1 6k 13.1 13.1

2 0.6k 1.31 1.31

3 0.06k 2.18 2.18 0.13 0.13

4 150 0.33 0.33

5 60 0.13 0.13

B) Parallel Circuit

Table 3 shows the comparison between the value of current and voltage across the
resistors obtained by using Proteus Software and manual calculation for the circuit in
Figure 2.

Table 3: The Comparison between the value of current and voltage across the
resistors obtained by using Proteus Software and manual calculation for the circuit in

Figure 2.

No Resistance (Ω) Current, I (A) Voltage (V)
Proteus Manual Proteus Manual

Software Calculation Software Calculation

1 6k 2.49m 2.502m 14.9 15.01

2 0.6k 0.02 0.025 14.9 15.00

3 0.06k 0.25 0.247 14.9 14.82

4 150 0.10 0.099 14.9 14.85

5 60 0.25 0.246 14.9 14.76

The value obtained using Proteus Software may differ from the manual calculation
because the values were rounded off in calculation.

Reflection

After doing this project, I am able to:
1) understand Kirchhoff’s Law and Ohm’s Law better;
2) apply voltage divider in calculation; and
3) stimulate a circuit by using Proteus Software.

Conclusion

1) The total resistance in the circuit can be calculated by adding the resistance
value of each resistor in the circuit.
RT = R1 + R2 + R3 + R4 + R5

2) For series circuit, the current that flows through each resistor is equal to the
total current in the circuit.

3) For parallel circuit, the voltage across each resistor in the circuit is equal to
the voltage supply.

4) The current entering a node is equal to the current leaving that node.
5) For a series circuit, the voltage divider rule can be applied to calculate the

voltage drop across the resistor.
VR1 = [R1/ (R1 + R2)] × [VS]

6) The Kirchhoff’s Law and Ohm’s Law had been verified.