US 4,055,733 A · Line level signal measuring device

Abstract

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.

Claims21

Dependent claims

A device for providing a measurement that represents the power level of a complex, alternating-current signal being conveyed over a data communications line, said measurement device comprising:

A. binary signal generating means having a plurality of outputs, each output corresponding to a different predetermined power level, said generating means generating binary signals at first ones of the outputs in a range defined by the value of the signal on the data communications line, binary signals being absent from the others of said outputs,
B. a plurality of visual indicating means connected to said binary signal generating means and arranged in an array, each said visual indicating means corresponding to a different predetermined power level of the signal on the data communications line and to an output of said binary signal generating means representing the same predetermined signal value, corresponding ones of said visual indicating means and said outputs being interconnected, and
C. blanking means connected to all of said visual indicating means and to said binary signal generating means for disabling said visual indicating means upon sensing a predetermined condition of the signal on the data communications line.

A device for providing a measurement that represents the power level of a modulated carrier signal on one of a plurality of communications lines in a data communications network, said measurement device comprising:

A. line selection means connected to all the communications lines for coupling a selected one of the modulated carrier signals to the output thereof as a selected signal,
B. a plurality of visual indicating means arranged in an array, each said visual indicating means corresponding to a different predetermined power level,
C. means for generating a plurality of binary signals at the corresponding outputs thereof, the binary signals being dependent upon the power level of the modulated carrier signal at an input of said generating means, each said binary signal output being connected to energize a corresponding one of said visual indicating means thereby to display visually the power level of the modulated carrier signal, and
D. blanking means connected to all of said visual indicating means and to said binary signal generating means for disabling all said visual indicating means upon sensing a predetermined condition of the modulated carrier signal.

1 more element

Dependencies are inferred from the claim text.

Line level signal measuring device

Life of this patent

Line level signal measuring device

Life of this patent

Abstract

Claims21