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Capacitor Discharge Time Formula Euler!

  1. Apr 8, 2016 #1
    I would like to understand how the Euler constant elevated to fractional exponent gave this result? 958mV someone please!? 2a9zigh.png
  2. jcsd
  3. Apr 8, 2016 #2


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    You did not give enough information for us to check everything, but the calculation is correct (I checked it on my old HP calculator).
  4. Apr 8, 2016 #3
    It is because my doubt is the fractional exponent, do not know why has this result!
    958mV no final entendeu!? Obrigado!
  5. Apr 8, 2016 #4
    Personal My question is in Euler's constant raised to a fractional exponent!
    Why and how ?? I do not know calculate HP, it's good we mastered without having to use HP,

    I have a teaching video, but honestly I still do not understand if you want to see the video? I have!
    Last edited: Apr 8, 2016
  6. Apr 8, 2016 #5


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    Charging of a capacitor is an exponential
    event. Voltage across capacitor rises exponentially as
    Vc=Vf(1-e-t/T). Time t is in the exponent, hence the part e-t/T is responsible for the exponential increase in voltage w.r.t time.
  7. Apr 8, 2016 #6


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    OK. Let us take it in steps:
    1. [itex]\frac{10}{47}= 0.212765957 [/itex]
    2. [itex]e^{-0.212765957}=0.808345302 [/itex]
    3. [itex]1- 0.808345302=0.191655 [/itex]
    4. [itex]5 \cdot 0.191655 = 0.958273 [/itex]
  8. Apr 8, 2016 #7
    Yes! , I understand, but using numbers,
    Watch this video!
  9. Apr 8, 2016 #8
  10. Apr 8, 2016 #9
  11. Apr 8, 2016 #10
    Sven Wonderfully Thank you!
  12. Apr 8, 2016 #11
  13. Apr 10, 2016 #12
    Personally, I'll be honest, here in South America (Brazil) I doubt that the Brazilian has a video explaining speaking Neper calculation on youtube to calculate the potentiation, constant = e ^ -0.212765957,
    I doubt (I dúvi [do] D + O = DO = DEODO talking!). Kkk! I doubt DEODO is when we doubt very much! is the Brazilian way of speaking! My God there are only understand potentiation, that's all, and I going crazy, studying (Mantissa) studies (Mantissa) kkkk lol (mathematics: decimal part of a logarithm) !:book::micoscope:
    (Matematicas: decimal part of a logarithm)! I wanted the help of North America, if possible help from the American continent LOL kkkk:oldbiggrin::partytime::bow::headbang::headbang::headbang:

    only thing i got! and I get it! Was this here!

    but not taught 10 ^ 0,3010

    how does it do??:headbang::headbang::headbang::oldgrumpy::oldgrumpy::oldgrumpy:
    Last edited: Apr 10, 2016
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