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Homework Help: Solving for resistor values in voltage divider circuit

  1. Nov 28, 2016 #1
    1. The problem statement, all variables and given/known data
    So I was studying an example and the picture given simply asked to setup a voltage divider for the values without solving for resistance. However... I want to know if I'm missing something or if this can even be solved:
    I attached the problem below.

    2. Relevant equations
    V1=Vs*R1/(R1+R2) VDR

    3. The attempt at a solution
    So I setup the circuit with 5 resistors in series with the ground after the first 3 resistors. However, when I try to solve for a voltage drop I get -15 on one side, so can't the other side with the negative values only be 9? Is it even possible to get a voltage drop of 15 originally and end up with -15 on the other side, considering the Vs is 24 v? Or are these values just not solvable?

    Attached Files:

  2. jcsd
  3. Nov 28, 2016 #2


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    Gold Member

    (1) A 30 volt swing with a 24V supply is not possible without an active circuit.
    (2) This is a rather stupid design request since unless the current draw from each of the voltages is utterly trivial, a passive resistance divider circuit is a non-starter as a decent design mechanism.
  4. Nov 28, 2016 #3


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    Staff: Mentor

    For the purpose of the exercise, perhaps assume the supply is 30V.

    Or for a little more challenge, assume the supply is ±24V.
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