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DC Generator: Equations & Graphs

  1. Jul 25, 2012 #1
    Hello everyone,

    I found on this website http://spiff.rit.edu/classes/phys213/lectures/lenz/lenz_long.html a very good explanation for AC generators. Particularly I am considering these two images:

    And attachment.php?attachmentid=49308&stc=1&d=1343211095.jpg

    I found those equations and graphs are quite interesting and wish to make a "change" so that they are valid for DC generators.

    My thinking is that: For the sine graph, I have to flip the negative part to make it positive. It will look something like this:

    Also, the equations for magnetic flux, the current and also the voltage basically stay the same but should be taken as the absolute value.

    Can anyone please correct me if I wrong?

    Many thanks,

    Attached Files:

    Last edited: Jul 25, 2012
  2. jcsd
  3. Jul 25, 2012 #2
    You are on the right track. The main difference between an AC and a DC generator is the means of making connections to the coil.
    In an AC machine 'Slip rings' are used to preserve the AC voltage and current. In a DC machine a 'commutator' is used to make the voltage and current in one direction, just as you have drawn in your last diagram.
  4. Jul 26, 2012 #3
    Thank you very much truesearch!
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