- #1
thuc
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Member warned to use the homework template for posts in the homework sections of PF.
Problems with First order RC circuit
- Context: Engineering
- Thread starter thuc
- Start date
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- Circuit First order Rc Rc circuit
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SUMMARY
The discussion focuses on solving a first-order RC circuit problem involving a 12V power source with 2Ω internal resistance and a parallel RC circuit consisting of a 3F capacitor and a 4Ω resistor. The key equations include the total response function V0(t) = K^(-1/2t) for part (a), where the switch is closed at t=0, and the challenge arises in part (b) when the switch is opened after being closed for a long time. The confusion stems from understanding the initial conditions of the capacitor and the implications of Thevenin's theorem in analyzing the circuit's behavior post-switch opening.
PREREQUISITES- Understanding of first-order RC circuit dynamics
- Familiarity with Thevenin's theorem
- Knowledge of capacitor charging and discharging processes
- Basic circuit analysis techniques
- Study the response of RC circuits to step inputs
- Learn how to apply Thevenin's theorem in circuit analysis
- Explore the mathematical derivation of capacitor voltage over time
- Investigate the effects of varying resistance and capacitance on circuit behavior
Electrical engineering students, circuit designers, and anyone involved in analyzing or troubleshooting first-order RC circuits.
- #2
Simon Bridge
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The image shows a 12V power source with 2##\Omega## internal resistance connected, in parallel, with a parallel RC circuit (3F and 4##\Omega##) via a switch.
The voltage across the capacitor is labelled ##v_0##.
Part (a) says the switch, open for a long time, is closed at t=0, find ##v_0(t)##.
Part (b) says the switch has been closed for a long time, and is opened at t=0, find ##v_0(t)##.
These two parts normally have a similar method of solution, so please show your method for part (a) so we can see how you are thinking.
For part (b) ... what is physically happening? What is the initial voltage on the capactor, what happens to the charge on the capacitor for t>0?
The voltage across the capacitor is labelled ##v_0##.
Part (a) says the switch, open for a long time, is closed at t=0, find ##v_0(t)##.
Part (b) says the switch has been closed for a long time, and is opened at t=0, find ##v_0(t)##.
These two parts normally have a similar method of solution, so please show your method for part (a) so we can see how you are thinking.
For part (b) ... what is physically happening? What is the initial voltage on the capactor, what happens to the charge on the capacitor for t>0?
- #3
- #4
cnh1995
Homework Helper
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Are you familiar with the response of a series RC circuit excited with a step input?thuc said:
Are you familiar with the Thevenin's theorem?
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