I was dealing with a 'single phase full wave bridge rectifier' with an inductive load in my lab class today. In order to calculate the efficiency values, I need the inductive reactance

$$2\pi fL$$

My confusion is about the frequency.

Because I am dealing with two lines (VAB) of my voltage supply, would I use 120Hz in the calculation? Or would I still use the base value of 60Hz?

I asked my professor but he said he would get back to me on that and I'd rather get this out of the way and what better site than this to ask?

Let me know if you guys have any ideas, or need clarification with my question. Thanks a lot.

  • 1
    \$\begingroup\$ I want to write an answer but dont have enough time to give a thorough explanation. If you have a circuit like this one then your transformer is directly fed off of the 60Hz, so you are working with 60Hz. Your load after the rectifier, due to the full wave rectifier, is going to apply a positive voltage twice per cycle, one on negative and one on positive peak. So often calculations for the load will use 120Hz as the regularity with how often that cap is recharged. \$\endgroup\$
    – Kortuk
    Commented Oct 10, 2012 at 0:09

1 Answer 1


Kortuk stated it correctly, 120cps for Full Wave, 60cps for Half Wave.

As a side note, but seldom taught in books or schools.
Unless you need High Voltages, like a Tesla coil.
Avoid designing a resonance filter, or harmonics thereof, as very high voltages can develop.
The voltage developed is from circuit 'Q', at resonance, not just turn ratios.


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