These dynamometers are suitable for testing of rotating machines AC or DC, basically these are also used as indirect method of loading of any machine. The construction features are basically an eddy current dynamometer is constructed in such away that it is able to indicate the torque produced at the rated rpm & current for the machine coupled to it.The prime mover becomes the motor under test & the dynamometer works as generator & its gets loaded by Eddy current clutch provided in the dynamo with the help of an exciter unit.