Is it possible to determine the turns ratio of a step-down transformer with just the following information?

120V (rms) 50 Hz AC mains supply connected to the primary windings. And a secondary voltage of 10V (rms) at the secondary windings output.

Is it a case of simply dividing both rms voltages given by the formula, Vp/Vs = Np/Ns, or do they need to be converted into their peak value?


The rms value is proportional to the peak value so the ration of $V_p/V_s$ will be the same regardless of if you use two peak values or two rms values.

  • $\begingroup$ thanks, just noticed that. so, would that calculation in the turns ration or does the formula need manipulating? $\endgroup$ – libraryjoe Oct 21 '16 at 19:58
  • $\begingroup$ The ratio of the voltages is the ratio of the number of turns. $\endgroup$ – M. Enns Oct 21 '16 at 20:01

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.