Split-pole exciters: Their design and application on diesel-electric locomotives

The development of the diesel-electric locomotive posed the problem of utilizing full engine horsepower over a wide range of locomotive operating conditions. One means devised to solve this problem was the use of a split-pole exciter, so designed as to give a generator load characteristic closely matching the constant horsepower output of the diesel engine over most of its range. Since the regulation results from the inherent exciter characteristics, this system employs a minimum of control equipment.