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CURRENT FLOW vs ELECTRON FLOW

Discussion in 'General Electronics Discussion' started by emanski, Apr 4, 2018.

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  1. emanski

    emanski

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    Mar 6, 2018
    As a beginning electronics hobbiest there are two concepts that are confusing to me. One is CURRENT FLOW positive to negative vs ELECTRON FLOW negative to positive.. In the explanations I've read some authors use one or the other to explain circuit function or both and I'm unable to fully understand how the circuit works. I also don't understand NEGATIVE voltage. Could someone help unconfuse me? This frustrates me because although I'm not a "rocket scientist" I'm reasonably intelligent!
     
  2. Bluejets

    Bluejets

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    Oct 5, 2014
    Just stick with conventional current direction ie from positive, out through the circuit and back to negative of the supply.

    For your second query, If you look at a split power supply having for example +12v...0v ....-12v it is the measurement with reference to the 0v rail.(remember reference to 0v)
    So if you hold your multimeter negative probe on the 0v and measure the first or top rail, you will get + 12v. Then by moving only your positive probe to the bottom rail the reading will be -12v.

    If you were to measure negative meter probe to -12v rail and positive probe to the 0v rail you would of course get a positive reading of 12v BUT then you would no longer be measuring with reference to the 0v rail.(remember reference)
    So with that in mind, what reading would you expect across +12v to -12v rails???
     
    Last edited: Apr 4, 2018
  3. davenn

    davenn Moderator

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    Sep 5, 2009


    for the most part do as Bluejets says
    It only when you want to get into depth about what is actually occurring in a circuit ... the actual flow of charge ... that you need to consider electron flow

    Dave
     
  4. Ratch

    Ratch

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    Mar 10, 2013
    It is important that you get the concept of charge carriers correct. That is why you should peruse #11 of this thread https://www.electronicspoint.com/threads/full-wave-rectifier.287940/#post-1762515 . Then, if you have any questions, just ask.

    Ratch
     
  5. Hopup

    Hopup

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    Jul 5, 2015
    It is certainly useful to understand the real direction of current "flow" in circuits.
     
  6. BobK

    BobK

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    Jan 5, 2010
    Current does not flow, charge flows. And negative charge flowing in one direction is equivalent to positive charge flowing in the opposite direction at the level of abstraction we normally work at in electronics. Only when you get into semiconductor physics does the type of carrier matter.

    Bob
     
  7. Ratch

    Ratch

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    Mar 10, 2013
    And, as I said before, if the charge carriers are positive, then the calculated mathematical charge flow is the same. If the charge carriers are negative, then reverse the result from the mathematical charge flow calculation.,

    Ratch
     
  8. Ratch

    Ratch

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    Mar 10, 2013
    Electrochemistry involves the movement of positive charged carriers in a solution. So does a proton steam from an accelerator.

    Ratch
     
    Last edited: Apr 5, 2018
  9. Cannonball

    Cannonball

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    May 6, 2017
    I go with the theory of electron flow. I had the same problem when I was learning electronics. The basic books on
    electronics say that electron movement is what produces a current through a conductor. It also says that protons are 1835 times bigger and heaver than electrons.

    I can't picture something as small as an electron moving something 1835 times bigger and heaver than it is.

    For practical use in electronics either way works for understanding and troubleshooting a circuit, but while you are learning stick with the books. After you get a good understanding of electronics go with whatever is best for you. They won't rewrite the books.
     
  10. Ratch

    Ratch

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    Mar 10, 2013
    Who says that electrons move protons in a circuit? Protons are part of the atom's nucleus and are stationary.

    You will be in for big trouble and confusion if you first ask what the polarity of the charge carrier is. Especially if there are both kinds of moving charges in the circuit to be analyzed. The relative mass of the charge carriers are irrelevant. Only the charges they carry have any significance. A single charge carrier the size of a cannon ball has the identical effect as the same charge on a spec of dust. Moving charges make up current, not the mass of the charge carriers. Only after a calculation is made according to the mathematical method, which assumes positive charges come out of the positive terminal of a voltage/current source, should the question of what is the real physical direction of the current even be asked. Usually is not necessary to ask that question. Ammeter and semiconductor manufacturers solved that problem long ago by marking their products according to the mathematical convention. Books and literature that delve on solving circuit problems according to the polarity of the charge carriers are off on a tangent to Nevereverland. They seem to forget that there are just as many positive charges in the universe as negative ones.

    Ratch
     
  11. davenn

    davenn Moderator

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    Sep 5, 2009
    time to close
     
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