ABSTRACT
In nearly all conventional hysteresis machines, the rotating magnetic field is produced by three-phase currents fed to a distributed winding in the stator. The drive arrangement for the field system was conceived to provide its smooth rotation at a constant speed during a test run and also allow the speed to be varied gradually and smoothly from a high value down to standstill when so required. The rotor arbor, the part to support the annulus, was made of Perspex to keep the rotor weight to a minimum causing negligible thrust on the lower bearing of the housing and also to avoid any induced eddy currents. The principle of torque measurement was to strain the torque arm by the developed torque and relate the strain to torque in Nm using a suitable transducer. Two search coils were wound round the rotor annulus on the side matching the interpolar axis for miscellaneous tests.
