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How is sinusoidal current generated?

  1. Jan 5, 2015 #1
    I'm delving into AC as well as attempting to understand the various wave forms used in electrical engineering, and I am curious how engineers are able to generate current which alternates in a sinusoidal manner. What specific phenomena allows us to achieve this? Is it a special circuit, or does it have to do purely with the electromagnetics of a current generator?

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  3. Jan 5, 2015 #2

    Doug Huffman

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    Circular function relative motion between magnetic flux and conductor.
  4. Jan 5, 2015 #3


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    is the usual mechanical way ( power generating station, alternator in a car)

    it can also be done purely electronically
    say a Wien Bridge oscillator

  5. Jan 5, 2015 #4

    Doug Huffman

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    HIgh current inverters are problematic. In my industry we used zero to adjustable low frequency stepping resistors to roughly simulate 3-phase 'alternating' current.
  6. Jan 5, 2015 #5


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    You can also use a Waveform Generator IC to make sine, triangle and square waves (as well as other waveforms). That is how basic signal generator equipment works:


  7. Jan 5, 2015 #6


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    Hydroelectric generators (the kind at big power stations run by water, such as at the Hover Dam) automatically generated AC electricity. For that matter, ANY uniformly revolving power source (wind, water, whatever) will cause a generator to produce AC electricity.

    It's producing DC electricity that is difficult ... it is normally done they easy way by first generating AC, which is easy, and then using a full wave rectifier and associate circuit to convert it to DC.
  8. Jan 6, 2015 #7


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    The current alternates in a sinusoidal manner because of the natural geometry involved in a rotating polarized magnetic field intersecting a wire. As said previously, creating DC is problematic. Producing currents requires changing magnetic fields. Simple motions result in sinusoidal currents.
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