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Homework Help: Help with home work question, RL circuit

  1. Feb 20, 2009 #1
    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 kirchoff 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...


    Attached Files:

  2. jcsd
  3. Feb 20, 2009 #2
    is there any simple way of calculating i1 in the circuit, that would make things a lot easier.
  4. Feb 20, 2009 #3
    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.
  5. Feb 21, 2009 #4
    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.
  6. Feb 21, 2009 #5
    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.
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