Transformers are used in a wide array of electrical or
electronic applications, providing functions that range from isolation and
stepping up or stepping down voltage and current to noise rejection,
signal measurement, regulation and a host of functions particular to
In order to test that a transformer will meet its design
specification, a number of functions should be tested and one of the most
commonly used tests is turns ratio.
This technical note will review briefly the basic theory
of turns ratio and then introduce some additional issues that should be
considered when testing this critical transformer characteristic.