due to variation of ohmic resistance in field circuit, using resistance switching in or out of circuit step by step

Full Title

Circuit arrangements for charging or discharging batteries or for supplying loads from batteries > for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle > Regulation of the charging current or voltage by variation of field > due to variation of ohmic resistance in field circuit, using resistance switching in or out of circuit step by step