Engineering Help with home work question, RL circuit

AI Thread Summary
The discussion revolves around solving for the current i(t) in an RL circuit defined by the voltage function vf= 4(u(t)-u(t-1.8))v. The user has successfully evaluated the circuit for t<0 but struggles with the range 0<t<1.8, particularly in finding the forced response as t approaches infinity. They express confusion regarding the impact of a controlled current source on their calculations using Kirchhoff's voltage law. Another participant suggests a simpler method to calculate the current i1, referencing the independent voltage source in the circuit. The original poster plans to share a solution and a clearer circuit diagram to aid understanding.
Quboid
Messages
6
Reaction score
0
vf= 4(u(t)-u(t-1.8))v

I have to find i(t), for the attached circuit. I already evaluated it for t<0. But i a having problems in the rage 0<t<1.8.

I am at the point where i have to find the forced response, so o let t tend to infinity
(t->infinity). And so the Inductor acts like a short circuit, the problem i have is find the current that passes where the inductor short circuits, I get confused by the controlled current sources.

I so far used kirchhoff voltage law to find three equations, but i am not sure i am correct, nor what to do with the dependent current source that finds itself in an equation.
Thanks for helping...

Quboid...
 

Attachments

  • RL.001.jpg
    RL.001.jpg
    11.5 KB · Views: 433
Physics news on Phys.org
is there any simple way of calculating i1 in the circuit, that would make things a lot easier.
 
Ok, i am thinking i1=i-(4v/5ohms). Note i got the 4 volts( which is supplied by the independent voltage source) from the scalar function vf, when evaluated in the range 0<t<1.8.
 
I've never seen some of the circuit elements in your drawing. Who's reinventing electronics and why?

I think if you want any help, you're going to need to decode that stuff.
 
Sorry about that. I didn't use a circuit schematic program to draw the circuit. I actually labelled them. I was hoping that would be sufficient. I solved the question yesterday one hour before the class. I will post the solution and a proper diagram shortly.
 
Thread 'Have I solved this structural engineering equation correctly?'
Hi all, I have a structural engineering book from 1979. I am trying to follow it as best as I can. I have come to a formula that calculates the rotations in radians at the rigid joint that requires an iterative procedure. This equation comes in the form of: $$ x_i = \frac {Q_ih_i + Q_{i+1}h_{i+1}}{4K} + \frac {C}{K}x_{i-1} + \frac {C}{K}x_{i+1} $$ Where: ## Q ## is the horizontal storey shear ## h ## is the storey height ## K = (6G_i + C_i + C_{i+1}) ## ## G = \frac {I_g}{h} ## ## C...

Similar threads

Replies
1
Views
935
Replies
10
Views
2K
Replies
1
Views
12K
Replies
2
Views
2K
Replies
13
Views
2K
Replies
3
Views
2K
Replies
2
Views
9K
Back
Top