Help understanding Potentiometer variable unloaded voltage divider

Discussion in 'Homework Help' started by Gixxer612, Sep 8, 2011.

  1. Gixxer612

    Thread Starter New Member

    Sep 8, 2011
    2
    0
    Hello everyone i'm new here. I am taking college courses in Electronics tech. and so far i'm mostly stuck on the work sheets with POTS and Rheostats.

    What i'm trying to understand is that the wipers location 1,2,3 and CW and CCW all at the same time

    its confusing me when the pot is set at CW and ER2 (1,2)

    i'm reading and trying to also understand the worksheets here also
    http://www.allaboutcircuits.com/worksheets/e_divide.html

    here are pictures of my worksheets , thanks in advance its driving me crazy

    homework worksheet 1


    homework worksheet 2
     
  2. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    5,448
    782
    In the context of the first problem 'CW' simply means that the wiper moves upwards on the schematic as the pot knob is physically rotated in a clockwise direction.

    ER2(1-2) is the voltage you would measure when placing a voltmeter across the pot R2 terminals 1 and 2, with the positive meter lead connected to terminal 1 and the negative meter lead connected to terminal 2
     
  3. praondevou

    AAC Fanatic!

    Jul 9, 2011
    2,936
    488
    Can you reformulate your question? What exactly is not clear?

    You have to divide the potentiometer into two parts for each of the requested values, e.g. for "midrange" in your first homework link (worksheet21) you divide the potentiometer into 2 x 2.5k (because it's 5k and the wiper is in the middle position).
    If you want to simplify the circuit, redraw it with the resistor values obtained, i.e. 2k, 2.5k, 2.5k, 3k. Then name the resistor joints according to where the potentiometer was before, i.e. 1, 2, 3 and then calculate all voltage levels between the resistors. That way you will find all values requested in the table.
     
  4. Gixxer612

    Thread Starter New Member

    Sep 8, 2011
    2
    0
    okay thanks , we have just learn only ohms law yesterday and watts law yesterday . i'm trying to get a good understanding of pots.

    what is the formula for finding Eout?
     
  5. justtrying

    Active Member

    Mar 9, 2011
    329
    358
    for Eout, if you haven't covered Voltage Divider yet, Ohm's law should come in handy - figure out the current, you know the resistance, and your answer is... V=IR
     
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