Schalteinrichtung zur Stromlosschaltung eines Transformators

摘要

The circuit has an additional winding (6) on the transformer (7). A monitoring part (32) with a differential amplifier (16) evaluates voltage differences in the additional winding arising from magnetisation differences of the iron core (9) depending on the secondary side load on the additional winding. The additional winding is associated with the primary winding. The number of turns in the primary winding is at least five times the number of turns in the additional winding. An interrogation circuit has an adjustable timing element which works in conjunction with a differential amplifier and a flip-flop.