Series opposing voltage sources

Discussion in 'General Electronics Chat' started by gorgondrak, Dec 1, 2015.

  1. gorgondrak

    Thread Starter Member

    Nov 17, 2014
    61
    1
    upload_2015-12-1_3-44-4.png



    This is from the AC book chapter 10.
    I am having trouble understanding how 2 series opposing ac voltage sources can add to 240 volts.
     
  2. Bordodynov

    Active Member

    May 20, 2015
    643
    188
    See

    Phase.png
     
  3. Bordodynov

    Active Member

    May 20, 2015
    643
    188
    Not -120 /180°→ 120 /180°
     
  4. gorgondrak

    Thread Starter Member

    Nov 17, 2014
    61
    1
    A 180 degree phase shift would put them series opposing.
     
  5. gorgondrak

    Thread Starter Member

    Nov 17, 2014
    61
    1
    The graphic you've shown shows two AC voltages that add to give a positive voltage. However, one of them is greater than the other making the difference between the two a positive number. In the book the same phase shift is shown, but the voltages are equal in value which should give no difference between them and no voltage. Am I missing something?
     
  6. Veracohr

    Well-Known Member

    Jan 3, 2011
    552
    76
    The bottom source has 180 degrees phase shift but also opposite polarity, so it's the same as the top source. Think of the phase as "internal" to the signal generator within the source and the +/- polarity as an "output" polarity of the source.
     
  7. Bordodynov

    Active Member

    May 20, 2015
    643
    188
    Rotating element (source) in the scheme does not change the magnitude and phase.
    And in the tabs (formulas) changed sign. This is mistake. Phase2.png
     
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