Since current flows from - to +, why not use + as "ground"?

Discussion in 'General Electronics Chat' started by zapp0, Nov 10, 2014.

  1. zapp0

    Thread Starter New Member

    Nov 10, 2014
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    Hi,

    i'm very much beginner in circuits only understanding the basics, still having problems understanding all the current flows in circuits. Of course one of the things is deciding how to decompose the circuit, which as per this portal is advised to be in the acutal electron flow rather than "classic" flow.

    This just leads me to the question, wouldn't it make more sense to have "gound" or "common" connection in circuits on + rather than the - pole?
     
  2. wayneh

    Expert

    Sep 9, 2010
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    It's not about making sense, it's a choice of convention so that we all use the same approach without having to state it all the time.

    It's purely convention that we usually call the lowest common voltage in a circuit, "ground".
     
  3. MaxHeadRoom

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    Jul 18, 2013
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    And it probably became the common practice due to the original theory that current flow was from +ve to -ve.
    Max.
     
  4. MrChips

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    Purely convention.
    When transistors were first available and applied, the PNP-type transistor was more common.
    It was common practice to consider the +VE side of the battery as GROUND.

    Also convention and convenience.
    There are automotive systems that use -VE battery as GROUND while others use +VE.

    There are high voltage supplies that use +VE or -VE as GROUND.

    It has nothing to do with charge carrier flow.
     
    Last edited: Nov 10, 2014
  5. crutschow

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    The negative of the power supply is typically called common or ground, as noted by others, but there are some exceptions. Notable is early versions of ECL (emitter-coupled-logic). Using positive for ground minimizes the effect of power supply deviations on the logic level as discussed here.
     
  6. Stuntman

    Active Member

    Mar 28, 2011
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    Need I mention that many cars around the 50's and prior had +6V "Grounds".

    If you read on this site's textbook about the origins of electricity, you find that the convention was derived by interpreting observations of statically charged materials using preconceived notions of physics. They just happened to have their conjecture backwards.
     
  7. MrChips

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    Don't become obsessed with the direction of current flow or the charge of an electron.
    Who says that an electron is negatively charge?
    Why is the Arctic at the North Pole and upwards?
    It is all relative and a matter of established convention.
     
  8. MaxHeadRoom

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    Wasn't Benjamin Franklin the prime offender? :)
    Max.
     
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  9. wayneh

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    In grade school, the teacher once told us that the planets went around the sun in a clockwise direction. I asked, from which vantage point? The teacher claimed it didn't matter. End result - I spent some time in the principal's office.
     
  10. Stuntman

    Active Member

    Mar 28, 2011
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    Why yes he was.

    Here is a snippet from the article for the OP that may clear the "why."

     
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  11. bertus

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  12. studiot

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    If the forum info is to be believed zapp0 was last seen yesterday at 4.27pm.

    Hopefully zapp0 will be back at some point.

    Most of the time it does not matter whether you choose positive or negative as your reference, or even somewhere inbetween that we call zero, just so long as you are consistent.
    And of course alternating voltage do not have positive and negative anyway.

    There are some circuits where it does make a difference, however.

    A good example would be galvanic protection circuits as widely used in industry, where the metal object to be protected is made positive or negative depending upon whether anodic or cathodic protection is employed.

    The change in automobiles from positive earth to negative earth allegedly leads to less corrosion at the battery terminals.
     
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