Discussion on “direct-current motor design as influenced by the inter-pole,” at Milwaukee, Wis., May 28, 1906

H. F. T. Erben: About fourteen or fifteen years ago I was interested in trying the effect of commutating the poles of a 500-kw. machine. The results were not satisfactory. In looking over the old data, I see now how close we came to attaining success: the pole Was properly proportioned, but we did not provide a sufficiently large magnetizing force for the commutating field. Wethen turned our attention to other matters, and did not renew our experiments on this kind of motor until two or three years ago, when the need of motors for machine-tool work, and generators for direct connection to high-speed steam-turbines, made it necessary to take up again the developing of the commutating-pole machine.