Protection device for monitoring systems - samples sensor outputs before transmission using logic circuit

摘要

The protection of monitoring systems, e.g alarm systems, against disturbance signals is provided by a synchronously operated sensor sampling unit. The outputs of various system detectors (1, 1a) is coupled over a logic circuit (5) and is periodically read into a short time contstant memory (6) operating under the control of a counter unit. The pulse output is fed over a control (2) to a monitoring unit (3) that is protected against any disturbances transmitted on the input lines.