04055733 is referenced by 14 patents and cites 3 patents.

A device for measuring the power of analog signals on telephone lines in a data communications network. A selection circuit couples a selected analog signal from one of the telephone lines to a measuring circuit. A full-wave rectifier and a low pass filter process and convey the selected signal to a plurality of open-loop comparators. Each comparator produces a binary signal that indicates whether the selected signal is greater or less than a reference power that corresponds to a predetermined power level. Each comparator energizes an inverter and driver that in turn energizes a light-emitting diode thereby to indicate the line signal power visually. However, the drivers are interconnected so only one light-emitting diode is energized at any given time. A blanking circuit disables the light-emitting diodes when rapid signal level changes occur. A self-testing circuit includes a damped oscillator for testing all the circuitry in the measuring device.

Title
Line level signal measuring device
Application Number
5/690884
Publication Number
4055733
Application Date
May 28, 1976
Publication Date
October 25, 1977
Inventor
Don I Falkenstein
Burlington
MA, US
Frank B Lezotte
Chelmsford
MA, US
David E Williams
Andover
MA, US
Jerry L Holsinger
Boston
MA, US
Agent
Cesari and McKenna
Assignee
Intertel
MA, US
IPC
H04B 3/46
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