1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Current Source

  1. May 18, 2014 #1
    1. The problem statement, all variables and given/known data

    Question 1: For the circuit below, determine what happens at maximum resistance when varying the 10K (decade box) variable load.

    Question 2:Explain the answer to the previous question, in terms of voltage compliance of the current source.

    Question 3:What causes detectable variations in output current as the load is varied within the compliance range.

    Question 4:Verify the explanation in the previous question, by making use of diagrams.


    2. Relevant equations

    No equations

    3. The attempt at a solution

    Solution 1:
    At maximum resistance, the saturation is reached, and the diode does not work properly anymore, as the collector current begins to drop.

    Solution 2:
    At maximum resistance, the collector current and the emitter voltage will change from being 1mA, and 1 V, respectively.

    Solution 3:
    The detectable variations in output current are the due to the the ammeter's installation into the circuit.

    Solution 4:

    In the diagram below, the top figure is actual data collected from experiment, and the lower image is a theoretical model of how transistors function. The similarities can be seen.


    Are all four of my answers correct?
  2. jcsd
  3. May 19, 2014 #2


    User Avatar

    Staff: Mentor

    Diode? :wink:

    Where did these values come from?

    Are you given an approximate value for β?
    Last edited: May 19, 2014
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted