Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Voltage dependent current source? Please help

  1. Apr 15, 2010 #1
    Voltage dependent current source??? Please help

    1. The problem statement, all variables and given/known data
    Attached the problem.


    2. Relevant equations
    ??


    3. The attempt at a solution
    Tried to Use KCL, not sure what else to do.
     

    Attached Files:

  2. jcsd
  3. Apr 15, 2010 #2

    berkeman

    User Avatar

    Staff: Mentor

    Re: Voltage dependent current source??? Please help

    Welcome to the PF. Show us your work so far. Show us your KCL equations.
     
  4. Apr 15, 2010 #3
    Re: Voltage dependent current source??? Please help

    I tried KCL at Va: (Vs-Va)/Rs+(Vb-Va)/100000+(Vx-Va)/2500=0
    and KCL at Vb: (VL-VB)/1000-.05Vx+(Va-Vb)/100000=0,
    So i have 2 equations and 4 variables assuming my work so far is correct, I am not positive on the sign conventions. Should I be using KVL, or Mesh analysis instead or in addition?
     
  5. Apr 15, 2010 #4

    berkeman

    User Avatar

    Staff: Mentor

    Re: Voltage dependent current source??? Please help

    KCL should work fine. Look at the circuit again, and see that Va = Vx, and Vb = VL.

    Also, be careful with your sign conventions -- either sum the currents leaving a node or going into it. I believe you were mixing signs in the first line (but the fact that Va = Vx kind of muddies that sign error anyway). I personally prefer to sum the currents leaving each node, but that's just me.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook