Elektronische Vorrichtung fuer eine Telegrafieueberwachungsschaltun

摘要

An electronic supervisory circuit indicates the condition of a telegraphy line being supervised without interfering with the transmission of the telegraphy signals. The supervisory circuit employs a holding circuit responsive to the detection of modulated line signals which maintains the output of the supervisory circuit during the periods when the modulated signals are transmitted over the telegraphy line. An auxiliary output is also employed to indicate the instantaneous condition of the line.