a transformer of which one winding is intended to be connected in series with a circuit in order to alter its voltage and the other winding is an energizing windinga transformer with a ratio of unity having one of its windings connected in series with the contact line and the other in series with an insulated return conductor NOTE - Booster transformers are positioned at intervals along the track to force current out of the rails and earth into the return conductor with the object of reducing stray currents.additional transformer integrated in one tank with the main transformer of an arc furnace which enables by means of a tap-changer controlling of a furnace supply voltage that is the sum of the secondary voltages of both transformers
A current transformer whose primary winding is in series with the catenary and secondary winding in the return conductor of a classically-fed A.C. overhead electrified railway.