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Lowest frequency of a transformer

  1. Jan 1, 2014 #1
    Hi , I've been wondering about this one thing.
    Well a transformer works on indcution , so a increase/decrease in voltage amplitude and/or periodical polarity reversal is needed to induce a current and voltage in the secondary.

    Now if we leave the current reversal aside for a bit and look at the increase then highest point and then decrease of a waveform that " feeds" the transformer primary , I wonder what's the lowest frequency a transformer can still be able to work ?
    The bigger the wavelength the longer it takes for the voltage to reach and then drop drom a certain level in one half period, but since we can also say that AC is just DC if looked at from a " point in time" perspective then since the time it takes for a very low frequency half wave to change is pretty long does the transformer secondary can still sense that?

    Or maybe I should ask , what is the lowest rate of change in voltage/current that a transformer can still work with ?
  2. jcsd
  3. Jan 1, 2014 #2


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    Last edited: Jan 1, 2014
  4. Jan 1, 2014 #3
    there are no limits of size , this is a theoretical question , i'm theoretically interested.

    So if i get it right from the article you gave me , a transformer could work on dc if only for one thing , after a given amount of time , or the time it took for a given material and size transformer core to reach saturation , so if the core won't saturate then the transformer could transfer usable power , but I guess it's just late nad I got something wrong because a static magnetic field can't induce current can it ..?
  5. Jan 1, 2014 #4


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  6. Jan 1, 2014 #5
    Theoretically, the minimal frequency of transformation is zero. Which is, of course, nonsensical in practice.

    Practically, it is one the many parameters of a transformer that must be very carefully chosen for optimal performance. It is in the domain of electrical engineering, not theoretical physics.
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