A Supplementary DC Machine Test for Sophomores

A blocked-rotor test may be used to determine curves for a family of dynamic operating characteristics for dc machines. Conventional performance characteristics may be predicted from these curves. The authors have used this test procedure to supplement the usual tests on machinery in the sophomore laboratory. The new procedure emphasizes the fundamental principles of machine operation and also points up the importance of certain details which have a significant effect upon performance. The test would logically precede the usual load tests. The latter are then anticipated with enthusiasm since they provide confirmation of performance predicted from the static tests.