Current transformer with terminal voltage determination facility

摘要

The turns of the primary winding (5) are bound with a conductive tape and held together by fasteners (8) so that a single uniform potential is presented outwardly. Within the secondary winding an annular capacitor (10) is formed by an insulating element (11) which carries conducting sheets on its inner and outer faces, connected by wires (15,16) to a secondary terminal box (9). The capacitance between the taped primary and the inner electrode (14) of the capacitor form the higher-voltage part of a potential divider, the lower-voltage part being the capacitor itself. The voltage appearing on a pair of wires (15,16) when connected to take account of individual unit tolerances, thus provides a measure of the voltage at the primary terminals (6,7).