Abstract: Methods and apparatus are provided for motor testing wherein performance characteristics are determined for motors exhibiting linear operating characteristic curves without making contact with shafts of the motors during testing. More particularly, a motor to be tested is operated in one direction to a no-load speed and then reversed with current and speed measurements being made during this testing period. A full load or stall point or points and a no-load point or points are determined from the measurements so that linear speed versus torque and/or current versus torque motor characteristic curves can be generated for the motor. Multiple voltages can be applied to determine a family of characteristic curves for the motor.

Abstract: A testing surge tests all of the individual coils within a coil assembly or multi-coil winding simultaneously. A pickup device is positioned adjacent each of the coils being tested. A voltage pulse is applied across the multi-coil winding. Each of the pickup devices generates a signal having a waveform representative of the magnetic field generated by the coil adjacent thereto in response to the voltage pulse. These signals are compared to each other to identify insulation defects, winding defects and polarity problems within the coils.

Abstract: A single source of energy is used to determine up to four armature coil or winding resistances and effectively up to four armature winding weld resistances for each test connection or index position of an armature being tested to thereby reduce the test time required for testing commutated armatures while reducing the complexity of the apparatus and test methods applied. Two preferably substantially diametrically opposite driven current paths through the armature windings are driven, and current and voltage measurements are taken at various commutator bars including commutator bars located adjacent current input ends and current output ends of the driven current paths. The resulting measurements and computations using these measurements are used to determine the winding resistances and ultimately the winding weld resistances for armatures and, in particular, for testing armatures for compliance with required specifications.