An A-C bridge method to measure core loss

A method for measuring total core loss by means of a modified Hay bridge is established. It is shown from Kirchhoff's laws that the new method is applicable when the time rate of change of flux in the core is nonsinusoidal and exhibits quarter-wave symmetry. An experimental comparison of the modified Hay bridge method and the reflecting wattmeter indicates agreement within about 2% when the waveform has said symmetry.