Depending on a design of the core distinguish transformers rod at which windings cover core cores, and armored at which core cores partially cover (reserve) windings. Rod transformers it is simpler on a design, they allow to simplify a design of windings and their repair. However gaps between a tank and the core have to be more, than at transformers with the armored core.
Transformers with regulation of tension on the secondary party carry out rod more often, and in transformers with regulation of tension on primary, i.e. high party, use armored cores. For reduction of losses from vortex currents cores of transformers collect from the separate sheets isolated from each other. Cross section of the core of the transformer of an electrorolling stock usually has the form of a step polygon, inscribed in a circle that considerably facilitates production of windings (there are no isolation bends at an angle).
On an arrangement of windings distinguish transformers with concentric and disk windings. In transformers with disk windings of the highest and lowest tension of a winding carry out in the form of the disks located on a core serially in the axial direction. All traction transformers of an electrorolling stock are lowering.
Except a secondary winding for power supply of traction engines through vypryamitelny installation, they have still a winding of a low voltage for power supply of auxiliary electrocars and furnaces of heating of insides of cars and cabins.