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 winding, trafo, millest üks mähis on ette nähtud seriaalselt ühendamiseks vooluahelaga, et muuta ja mõõta selle pinget, ja teine mähis on energiat mõõtev ja andev mähis, one which is often used towards the end of a power line to raise the voltage to the desired value