Schutzeinrichtung für elektronische und/oder elektrische Fernsprechschaltungen zur Begrenzung der internen Leitungsverluste.

摘要

A protection device for an electrical and/or electronic circuit (1) connected to a load (27), in particular a telephone, and to at least one external componenet (2) comprises sensor means (6) able to determine a common-mode current absorbed by the load (27), and to control generator means (7) arranged to generate a current signal (IL), the signal (IL) emitted by these latter varying in accordance with the determination effected by the sensor means (6) and being at least partly absorbed by absorber means (13) controlled by a control unit (5) connected to measurement means measuring the current passing through the line containing said load (27), said absorber means (13) being connected at one end (12) to a point (15) downstream of the load (27), said absorber means (13), on determination of a common-mode current passing through the load (27), varyinig the absorption of the signal (IL) emitted by the generator means (7), to result in a variation in the potential difference across its ends and hence a variation in the potential at the load (27), this variation limiting the current passing through this latter.