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Discussion » Questions » Science and Technology » Can you tell me for sure and certain which direction DC Electricity flows?

Can you tell me for sure and certain which direction DC Electricity flows?

Posted - May 1, 2017

Responses


  • 16819
    Towards Washington, of course.
      May 1, 2017 5:31 AM MDT
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  • 1268
    Good thinking, I was about to ask you the state or D.C...before I realized what you were getting at lol.
      May 1, 2017 5:33 AM MDT
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  • Yes.   The electrons flow from the positive to  ground.
      May 1, 2017 9:27 AM MDT
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  • 1268
    Is this proven?
      May 5, 2017 9:05 AM MDT
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  • We were taught that in diagram you show positive to negative but in reality the opposite is true.   I know it hasn't been fully observed so that might be what your talking about.
      May 5, 2017 9:20 AM MDT
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  • 1268
    I guess in reality it doesn't matter. Just that it is 'Electrical Theory' and still not fully understood amazes me. I suppose what you say makes sense though, since DC tends to have voltage drops over long distances. Thank you for answering this by the way. Not everyone wants to chime in on a serious question, so I usually try to keep it dumb. :)
      May 5, 2017 9:25 AM MDT
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  • True, We still only have a working knowledge on it and people find new novel circuits that don't behave as expected all the time.

    Yeah that's the only real problem with DC.   I have to deal with that fact on my panels.  Still the line loss is way better than conversion loss to AC to transmit in my application.  The loss from rectifying the AC square wave.   It's more efficient for me to set up a pulsed DC current and run DC circuits over the distance I use.

    I actually calculated it at about 15% line loss over the distance as opposed to the near 40% conversion loss plus the loss in rectifying the AC.
      May 5, 2017 9:37 AM MDT
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  • 44647
    From negative charges to positive charges.
      May 1, 2017 9:37 AM MDT
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  • 1268
    We were taught in Electrical theory it is still unknown. Is there a certain way to tell this for sure?

     I am studying to get my limited electrical license as it is needed to pull HVAC permits in some areas, but I am no electrical expert as most residential electricians I know aren't. There are a lot of wire pullers here but few electricians.
      May 5, 2017 9:09 AM MDT
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  • 318
    If you go back to the old vacuum tube, you will find that the electrons flow from negative to positive. If you hook a vacuum tube up backwards, you get no current flow.
    http://www.vacuumtubes.net/How_Vacuum_Tubes_Work.htm
      May 5, 2017 9:22 AM MDT
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  • 1268
    Thank you Maurice, I have to examine this.
      May 5, 2017 9:26 AM MDT
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  • 318
    Depends upon what you definition you are using.
    Power transfer.. power flows (is transferred) from the source to the load
    Electron flow   Electrons flow from the negative terminal, to the load and then to positive terminal (In the source they flow from the positive to negative)
    Conventional current flow.. current flows from the positive terminal to the load and back to the negative terminal  (in the source from the negative to positive)
      May 1, 2017 9:49 AM MDT
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  • 7683
    i think Glis and Element are right...!
      May 1, 2017 10:44 PM MDT
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  • 1268
    Why do you think this Veena?
      May 5, 2017 9:09 AM MDT
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  • 7280
    Not sure what motivated this question until I saw your HVAC comment. If this link doesn't help you sufficiently, let me know.

    When Benjamin Franklin made his conjecture regarding the direction of charge flow (from the smooth wax to the rough wool), he set a precedent for electrical notation that exists to this day, despite the fact that we know electrons are the constituent units of charge, and that they are displaced from the wool to the wax—not from the wax to the wool—when those two substances are rubbed together. This is why electrons are said to have a negative charge: because Franklin assumed electric charge moved in the opposite direction that it actually does, and so objects he called “negative” (representing a deficiency of charge) actually have a surplus of electrons.


    By the time the true direction of electron flow was discovered, the nomenclature of “positive” and “negative” had already been so well established in the scientific community that no effort was made to change it, although calling electrons “positive” would make more sense in referring to “excess” charge. You see, the terms “positive” and “negative” are human inventions, and as such have no absolute meaning beyond our own conventions of language and scientific description. Franklin could have just as easily referred to a surplus of charge as “black” and a deficiency as “white,” in which case scientists would speak of electrons having a “white” charge (assuming the same incorrect conjecture of charge position between wax and wool).

    https://www.allaboutcircuits.com/textbook/direct-current/chpt-1/conventional-versus-electron-flow/
      May 5, 2017 2:53 PM MDT
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  • 1268
    Thank you. I am studying electrical in-depth, I get a little obsessive about studying specific subjects.
    I will have some more serious questions later on I'm sure. My understanding of electricity is fairly basic and it helps to have people who are more educated in the subject. I am actually fortunate that four serious answers came in on this question.
      May 5, 2017 3:00 PM MDT
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  • 7280
    For a moment, I had originally though you were asking some kind of philosophical question---lol
      May 5, 2017 3:51 PM MDT
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  • 1268
    No, I try not to meander in anything that deep here.
      May 5, 2017 4:17 PM MDT
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  • 7280
    I understand your confusion, WW---it was the subject of a recent executive order signed with little fanfare behind closed doors.  (Be on the look-out for another one directing the history books on the Civil War to be re-written to explain the real causes behind the deceased Andrew's Jackson's  precognitive anger about the very same war.)

    And if you just continue to insert your batteries in the directions indicated in your flashlights---you will be just fine.
      May 5, 2017 4:00 PM MDT
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  • 1268
    He pulled the black wire out.
      May 5, 2017 4:16 PM MDT
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