by progressive reduction of resistance in series with armature winding

Full Title

Arrangements for starting electric motors or dynamo-electric converters (starting of synchronous motors with electronic commutators H02P6/20, H02P6/22; starting dynamo-electric motors rotating step by step H02P8/04; vector control H02P21/00) > for starting dynamo-electric motors or dynamo-electric converters > for starting an individual DC motor > by progressive reduction of resistance in series with armature winding