Ateneo De Zambaoanga University
CITS Department
Name : Philwin M. Hao
Group # 3
Experiment #8
Charging and Discharging RL Circuit
Objective: To verify time constant of RL circuits using LTspice XVII simulation software
Apparatus: Desktop or Laptop and LTspiceXVII simulation software
Circuit Diagram:
Original Circuit
Procedures :
1. Choose V1: 10 volts < VT < 40 volts
2. Choose Inductance value : 10H<L<100H
3. Choose R1, R2, and R3 : 10< R < 100
4. Connect all the resistors and DC source using LTspice VII
5. Measure current thru the Inductor using the simulation software if the SPDT switch is at position A.
Show Graph. Is the inductor charging? Is the current thru the inductor equals to V1/R1? Is the time
constant equals to L/R1?
6. Measure current thru the Inductor using the simulation software if the SPDT switch is now at position
B. Show Graph. Is the inductor discharging? What is the current equation of the circuit? Is the time
constant equals to L/(R2 +R3)?
7.
Show Simulation Result: Save as a pictures with corresponding parameters ( limit 10 pics )
A.
B.
Show computation result for theoretical side:
Observation:
First I observe the position a in the circuit have a voltage source resistor and an inductor. So in my
perspective due to it having an external voltage source its charging the inductor in the circuit. While in
position b since it doesn’t have a voltage source its discharging the inductor.
Conclusion:
In conclusion first the inductor is charged in position A while its being discharge in position b.