A continuous current generator for high voltage

P. L. Alger: The chief interest of Mr. Bergman´s paper is in the commutation of the machine, that is, the chief theoretical interest. Mr. Bergman is building a machine for proper commutation. To get the commutation we must have low reactance and we must have a very definite commutating flux to make the voltage induced by the flux exactly overcome the voltage of the changing current. Unless a machine is very perfectly compensated, you cannot hold that flux just right because when the load changes, the armature reaction makes the neutral point shift so the first thing is to obtain very perfect compensation. Mr. Bergman has done this. Another thing that helps commutation is his distributed field winding, as by this means he has a relatively gradual rise of flux on leaving the neutral, as compared with the salient pole winding.