Circuit arrangement for automatic overload protection of current transformers

摘要

The circuit arrangement for automatic overload protection of current transformers, especially for preventing overvoltage and overload occurrences and their consequences when the secondary circuit is interrupted, contains, according to the invention, an electronic overvoltage sensor and short-circuit unit (5) which is connected in parallel with the load (4) that is connected to the secondary terminals (2, 3), is preferably constructed using thyristors (14, 17), diodes (15, 18) and zener diodes (16, 19) and, in the event of an unacceptable rise in the voltage which can be measured on the secondary terminals (2, 3) of the current transformer (1), automatically short-circuits the terminals (2, 3) and opens them again when the voltage drops. The circuit arrangement according to the invention operates fully automatically and requires no external operating energy. <IMAGE>