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AC flowing through a cap. What actually happens?

Discussion in 'General Electronics Chat' started by qtommer, Feb 25, 2011.

  1. BrownOut

    BrownOut Banned

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    I really see no contradiction when talking about current flow. As already pointed out, charge doesn't really "flow" in accordance with the meaning of the word, rather the average direction of charge is a flow of current. I see no problem with the language as such, only a constant disruption of a technical forum. And I see no contradiction of speaking of charging a capacitor. These are indeed abstractions, but very, very useful ones, and as such are prefectly acceptable.
     
    Last edited: Feb 28, 2011
  2. Ratchit

    Ratchit Well-Known Member

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    MrAl,

    No, it is anything comprehensible.

    Technical descriptions should not be redundant. We are not writing poetry here. I was illustrating redundancy gone amok.

    Why not just say "The voltage is proportional to the current"? You seem to imply that I am against using the word "current", even by itself. I am not.

    Yep, that's funny.

    It won't do to disagree about everything.

    That is why the clerk is selling them instead of using them. I hope you educated him a little.

    Ratch
     
  3. Ratchit

    Ratchit Well-Known Member

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    crutschow,

    It is more poetic, that is for sure. But not more descriptive.

    True.

    The best way to say it is "The charge flows from positive to negative". Completely correct and concise.

    Yes, I wonder sometimes what this world is coming to.

    Ratch
     
  4. dave

    Dave New Member

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  5. Ratchit

    Ratchit Well-Known Member

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    BrownOut,

    I don't either. I see a redundancy.

    The average direction of the drift velocity is a flow of charge which means current.

    I already explained the redundancy problem.

    I already explained why a capacitor does not charge.

    Those are misleading terms and phrases which just about everyone has accepted. Better descriptions exist.


    Ratch
     
  6. BrownOut

    BrownOut Banned

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    That's just another abstraction, just as current flowing. Not one is more correct or concise.

    I don't.

    No, it's current.

    And I explained why there is no redundancy problem.

    You're explanation was rather flawed. Charging is accurate, as to charge means nothing more than to redistribute charge.

    There is nothing misleading about it. Nearly everone understands what it means.
     
    Last edited: Feb 28, 2011
  7. MrAl

    MrAl Well-Known Member Most Helpful Member

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    Hi Ratch,

    Educate him? How did i educate him? I think you missed something here as I wrote:
    "I was very disappointed so i connected them up to my 12v battery through a resistor to energize them directly, but still none of them would energize. I was so disappointed..."

    So the batteries would not energize even though i connected them up to a 12v battery through a resistor? That seems contra to what you had been saying about energize. How could it be that, having say 1 amp of current, the batteries did not energize? How is this even possible? Did they all have to be open or short circuited internally? What if one was resistive? Explain.

    Isnt it also nice that the batteries had one amp of current? I like to give them all current once in a while :)
     
    Last edited: Feb 28, 2011
  8. Ratchit

    Ratchit Well-Known Member

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    BrownOut,

    Not true. You can say "charge flows into this node" or "strong current exists in that wire". That tells you just as much as you showed above.

    I don't think they are abstractions. I think they are redundant and misleading words and phrases that just about everyone has come to accept. You know, like astronauts "walking" in space. When the space program first started, they didn't walk in space, did they?

    It is for them to decide to be concise and correct, or to be one of the boys and sloppy with the language.

    Ratch
     
  9. BrownOut

    BrownOut Banned

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    I never claimed it didn't. But charge flowing is only another abstraction.

    I don't care about astronauts walking in space. I reject the terms about current and charge being redundant or misleading. This language has been understood for over 100 years, so no problem ever existed.

    There is nothing sloppy about speaking in a way that is easily understood.
     
  10. Ratchit

    Ratchit Well-Known Member

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    BrownOut,

    No it is a description. Current flowing is charge flow flowing. That is a redundancy.

    Let the readers decide.

    Let the readers decide.

    I don't think you did. At least not very well.

    In what way was it flawed? Do you redistribute charge in a battery when you "charge" it?

    Yes, they understand what a misleading statement means, even if it is literally untrue or redundant.

    Ratch
     
  11. Ratchit

    Ratchit Well-Known Member

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    MrAl,

    I guess I did miss something. Did you energize them with the correct current at the correct voltage for the corect period of time?

    Ratch
     
  12. BrownOut

    BrownOut Banned

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    It is a description, and not a redundancy. Charge flow is just another abstraction.

    They will. I'm gifting my years of experience and knowledge.

    I don't care what you 'think.' I'm interested in facts only.

    I'm talking about capacitors, since that was the orignial topic.

    They understand its accuracy from an abstract standpoint, just as your statements are abstract, and no more truthful and less useful.
     
    Last edited: Feb 28, 2011
  13. MrAl

    MrAl Well-Known Member Most Helpful Member

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    "I was very disappointed so i connected them up to my 12v battery through a resistor to energize them directly, but still none of them would energize. I was so disappointed..."


    I didnt have to choose the voltage. I only had to apply the current and allow them to do whatever they are going to do for the period of time expected for them to finish. You said 'energize' was a good enough word, so that's what i said.
     
    Last edited: Feb 28, 2011
  14. Ratchit

    Ratchit Well-Known Member

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    BrownOut,

    No, it is a description.

    That was an example of a misleading description.

    So do I. I said that "current flowing" was misleading and redundant. I never said that "current" or "charge" by themselves were misleading or redundant.

    No problem perhaps, but still not correct.

    Correct. "current exists" and "charge flow" is speaking in a way that is easily understood.

    Ratch
     
  15. Ratchit

    Ratchit Well-Known Member

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    MrAl,

    OK, then the batteries should have done what batteries do, they energize. See Sears: Online department store featuring appliances, tools, fitness equipment and more

    Ratch
     
  16. BrownOut

    BrownOut Banned

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    It's just an abstraction, no more correct than how it's been communicated for 100 years.

    Neither did I. I was condensing.

    No less correct than anything else I've heard.

    No more easy or correct than what most everyone else understands.
     
  17. Ratchit

    Ratchit Well-Known Member

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    BrownOut,

    Let the readers decide.

    Sure had me fooled.

    If you say so. Let the readers decide.

    Let the readers decide.

    Ratch
     
  18. BrownOut

    BrownOut Banned

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    After they get to take advantage of my years of experience and knowledge, then they can.

    Not surprised by that.

    Now that's redundant.
     
    Last edited: Feb 28, 2011
  19. Ross Craney

    Ross Craney New Member

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    Like a bunch of 5 yr olds in a schoolground arguement. Surely you all have better things to do than attempt to get the last word in.
     
  20. MrAl

    MrAl Well-Known Member Most Helpful Member

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    I repeat what i had said earlier:
    "I was very disappointed so i connected them up to my 12v battery through a resistor to energize them directly, but still none of them would energize. I was so disappointed..."



    Hello again,

    But i said that they did not energize. I applied a current to energize them but they did not energize. You forced me to use the word 'energize', so i used it. Now i say that they did not energize yet you are sure they did energize.

    But even more to the point:
    "I applied a current to energize the battery and it did energize."
    Now i ask the question, did the battery change chemically or did it just dissipate heat? (dissipate heat means it did not change chemically in a way that would allow it to deliver energy later when we go to use the battery for some power purpose)

    It's also interesting that so far all of the links i have found on the web that talk about 'energizing' a battery seem to indicate that energizing a battery means to do something special to it other than charging it. For example, it's an old battery and wont hold a charge anymore and you want to do something to it to get it to hold a charge again ie 'energize' the battery or 're energize' the battery.

    Oh yeah, next discussion topic might pop out at you above, how does a battery "hold a charge" ha haaaaa.
     
    Last edited: Feb 28, 2011
  21. crutschow

    crutschow Well-Known Member Most Helpful Member

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    Not quite. If you want to be "Completely correct and concise", which seems to be one of your obsessions, one would say "The positive charge flows from positive to negative". Of course if you use current, you wouldn't have to add that adjective, since the common definition of current assumes the carriers are positive.

    To paraphrase Humpty Dumpty (with apologies to Lewis Carroll): When a common technical phrase is used, it means what most people understand it to mean -- neither more nor less.

    By the way, did you ever study to be a lawyer? That could explain your rather torturous endeavor to nit-pick the accepted meaning of so many common technical expressions.
     

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