Full wave bridge rectifier

Discussion in 'General Electronics Chat' started by bwd111, Jul 24, 2013.

  1. bwd111

    Thread Starter Member

    Jul 24, 2013
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    What is the output frequency of a full wave bridge rectifier connected to a 120v 60hz input
     
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    120 Hz. Hertz
     
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  3. absf

    Senior Member

    Dec 29, 2010
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    120 Hz without the filter capacitors....
     
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  4. Ron H

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    Apr 14, 2005
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    Also 120Hz with the filter capacitors, if there is any load.
     
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  5. jessietechele

    New Member

    Jul 23, 2013
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    120HZ im sure
     
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  6. studiot

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    Nov 9, 2007
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    It should be observed that the output of a bridge rectifier is not alternating (AC) and therefore does not strictly have a frequency in the AC sense.

    However, it is not steady DC either. It is in fact pulsing DC or unidirectional current with a pulse repetition time equal to the pulse length of .00833... seconds - which equates to a pulse repetition rate of 120 pulses per second.

    The graph of the output is not a continuous function.
     
    Last edited: Jul 25, 2013
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  7. hasnain

    New Member

    Feb 9, 2012
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    120 hz at out put.
     
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  8. Shagas

    Active Member

    May 13, 2013
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    And what would be the repetition or frequency without the Filter caps/without load ?
     
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  9. GopherT

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    Nov 23, 2012
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    You are getting into semantics and I am not sure I are with definitions. AC is any non-DC waveform (including your "pulsing DC", square wave, rectangular e wave, triangle, sweep, ...) and therefore, any "waveform". AC does not have to be a sine wave, it does not have to oscillate +/- ground (it can have a DC offset and commonly does. AC is any signal that is not steady DC. Steady DC is rare other than battery with only a resistive load and no outside interference.

    These non-sine wave AC signals are the whole point of the so-called "true RMS" volt meters. The are capable of measuring the true RMS voltage of non-sine wave AC signals.
     
    Last edited: Jul 25, 2013
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  10. studiot

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    @gopherT

    I don't recall mentioning sine waves.

    What do you think the word alternating means in AC?
     
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  11. wayneh

    Expert

    Sep 9, 2010
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    I'm with you on that. The term is alternating current, not alternating voltage. The thing that alternates is the direction of the current, not the magnitude.

    Unfortunately the term "AC" is also widely used to refer to the changing magnitude of a DC voltage, the ripple around the mean DC. The electronics world seems to have no good acronym for this, to distinguish it from true AC.

    Personally, I've decided to reserve the term "AC" for truly alternating current and use less handy, but more precise, terms for rippling DC.

    I would still agree however that the answer to the OP's question is 120Hz. It's more complicated than that because it's not a sinewave and therefore has multiple frequencies, but I doubt the OP cares about that. He appears to be long gone anyway.
     
  12. MaxHeadRoom

    Expert

    Jul 18, 2013
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    +1 on that.

    For me the key is the current (alternating) change of direction, rather than pulsating.
    Max.
     
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