The magnesium-copper sulphide rectifier battery charger for railroad passenger cars

When the railroads began air conditioning their trains, adequate charging of the storage batteries associated with air conditioning systems became an important factor in the new development. The capacity of the axle driven d-c generator charger was increased; however, supplementary charging was frequently necessary or desirable, particularly when the axle generators were not operating. The railroads met this problem by using portable motor generator sets, wiring their stations and yards with standby service and through the use of small, compact, dry-disk rectifier battery chargers of sufficient current capacities to charge one or two car batteries simultaneously. The first rectifier developed for this service made use of the magnesium-copper sulphide dry-disk type. The mechanism of this rectifier is here briefly discussed, design features enumerated, and the type of rectifier battery chargers developed for railroad use described.