The analytical determination of the steps in the starter of a series motor

The this paper a simple analytical method for calculating the resistance steps in the starter of a series motor is given, and examples are worked out illustrating the application of the method to the series motor and to two series motor arranged for series-parallel control. The solution of the problem entails a knowledge of the magnetization curve, or of the speed curve, of the motor; but no graphical construction is necessary for obtaining the results. The sets of curves in Figs. 3 and 5 are added to illustrate the results.