Rectifier

Discussion in 'General Electronics Chat' started by bwd111, Aug 8, 2013.

  1. bwd111

    Thread Starter Member

    Jul 24, 2013
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    Is the voltage output of a rectifier known as pulsating direct current
     
  2. bertus

    Administrator

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  3. wayneh

    Expert

    Sep 9, 2010
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    To me, yes. We've had this come up several times lately because you could also legitimately refer to it as DC with a large AC component. The term "AC" is often used where the current does not truly reverse direction, it just fluctuates in magnitude. I personally want to avoid that because it's ambiguous. "True AC" in my world has to allow for current in both directions.
     
  4. MaxHeadRoom

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    Jul 18, 2013
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    +1 on it.;)
    Max.
     
  5. tshuck

    Well-Known Member

    Oct 18, 2012
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    I would consider it to be rectified AC, as this typically suggests some sort of half-wave signal with no negative portion to the waveform. Perhaps calling it DC with a ripple would suffice, depending on stability and how much AC component the waveform has.

    I would reserve "pulsating DC" for a waveform with much higher harmonic content, e.g. rectangle waveforms.
     
  6. crutschow

    Expert

    Mar 14, 2008
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    Pulsating DC has an AC component. Any signal that can be coupled through a capacitor is AC and certainly the ripple or pulsating portion of a rectified signal can be coupled though a capacitor. Thus it is an AC signal superimposed upon an average DC value that is not zero. If you connect a multimeter to the output it will measure the AC component on the AC range, and the average DC component on the DC range.

    "True AC" may be defined in some worlds but it is not a commonly defined technical term in the engineering world. :rolleyes:
     
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  7. bwd111

    Thread Starter Member

    Jul 24, 2013
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    I choose pulsating on quiz. But wanted to know if I got the answer correct. The choices were polarized,pulsating,pure or sinusoidal direct current
     
  8. gootee

    Senior Member

    Apr 24, 2007
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    You could make an argument for all four of those but the best answer is probably "pulsating".

    It is "polarized", since it is all of one polarity.

    It is "pulsating", since it is not a single constant voltage. But it's not pulse-shaped.

    It is "pure" DC in the sense that it is all of one polarity. But it has an AC component so that answer is probably incorrect.

    It is sinusoidal, in part. It's not a complete sinusoid. But if I only gave you the data points from a small section of a sine wave, you could eventually identify it as "sinusoidal", as opposed to, say, parabolic, or circular, or elliptical, et al.
     
  9. MaxHeadRoom

    Expert

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    When do you find out the 'correct' answer?
    Max.
     
  10. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    "Pulsating" is by far the best answer from those four choices, he's got it right.
     
  11. bwd111

    Thread Starter Member

    Jul 24, 2013
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    It was pulsating just got the paper back. I got 89% and was a class I cared less if I passed but I did and 4 of the answers I got were from this forum so I say I my own I got around 83%
     
  12. MaxHeadRoom

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    Jul 18, 2013
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    So there were over 66 questions?
    Max.
     
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