Overvoltage limiting on electronic telephonic installation - utilises saturable magnetic transformer with closed magnetic circuit coupled to lines

摘要

Electronic equipment in telephonic exchanges is susceptible to damage from overvoltages occurring on the lines as a result of atmospheric discharges. A saturable magnetic transformer coupled to the lines limits the overvoltage condition to a safe level. Overvoltages on telephonic lines are limited by a saturable magnetic transformer (3) with two windings (1, 2) wound with their axes (T1, T2) perpendicular. The windings are wound on the same magnetic core support (C) to annul mutual coupling. The core presents a closed magnetic circuit.