Discussion on “excitation of alternating-current generators” (Rushmore), Boston, Mass., June 28, 1912. (see proceedings for July, 1912)

B. G. Lamme: I have only a few points to bring up in connection with this paper. On page 1566 is a table which I did not understand. For example, the constants given for single-phase and three-phase windings do not agree, and yet very frequently three-phase windings are used to give singlephase. However, I may not understand how these constants are used. In the method of calculation which I have been using, I do not have any fixed constants. I first work out the magnetic field distribution. From this I then derive the constants for each individual case. The use of a constant is all right in the hands of a skilful designer, if he knows how it is derived, but in special designs it is likely to be misleading. The table given probably refers to a standard type of machine in which the constant has been determined, and has been proved to be constant in all cases.