US4113998A
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Testing electrically conductive lines to determine electrical characteristics thereof
Assignee: Teradyne Inc
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Filing: 1975-10-14
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Granted: 1978-09-12
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Expires: 1995-10-14
Abstract
Abstract A two-wired telephone testing system employing a low frequency test signal which is a submultiple of the power line frequency. This test signal is applied between the two-wires or between either wire at a point of potential reference (ground). A measure of the integrated value of the current between the connected points is then made for a period equal to one-half cycle of the applied signal with one polarity and one-half cycle with the polarity of the measured signal reversed. The integration periods are selected to be in phase with the applied signal for determining conductance and 90° out of phase for determining susceptance. Direct current measurement can also be made for the same time periods.
Inventors
- 👤 Glynn R. Ashdown
- 👤 Thomas McCartney
- 👤 Bruce Holmes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:35
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/22; H04M3/26; H04M3/28; H04M3/30; H04B; H04B3/00; H04B3/02; H04B3/46
Claims Analysis
Total Claims: 51
Claim 1
Independent Claim
170 words
A method for testing two-wire lines in an environment where the predominant power distribution is at a frequency f 1 , to determine the electrical characteristics thereof comprising the steps of, (a) applying an alternating current waveform of specified frequency to one of said wires, said frequency being substantially 1/2 f 1 , a submultiple thereof or an odd harmonic thereof no greater than 250 Hz, (b) measuring the current on the one of said wires to which said alternating current signal has been applied, (c) generating a signal, including a portion proportional to and of the same polarity as that of said measured current for a period equal to an integer number of half cycles of said applied alternating current signal and equal to an integer number of full cycles of f 1 , (d) and providing an output signal proportional to the integrated value of said generated signal over said period, said period being selected to be in a known phase relationship with said applied alternating current signal.
Claim 2
Independent Claim
170 words
A method for testing two-wire lines in an environment where the predominant power distribution is at a frequency f 1 , to determine the electrical characteristics thereof comprising the steps of, (a) applying an alternating current waveform of specified frequency to one of said wires, said frequency being substantially 1/2 f 1 , a submultiple thereof or an odd harmonic thereof no greater than 250 Hz, (b) measuring the current on the one of said wires to which said alternating current signal has been applied, (c) generating a signal, including a portion proportional to and of the same polarity as that of said measured current for a period equal to an integer number of half cycles of said applied alternating current signal and equal to an integer number of full cycles of f 1 , (d) and providing an output signal proportional to the integrated value of said generated signal over said period, said period being selected to be in a known phase relationship with said applied alternating current signal.
Claim 3
Dependent Claim
103 words
A method in accordance with claim 1 and wherein in step (c) said generated signal includes both said first portion and a second portion, where said second portion is proportional to said measured current, and of reversed polarity from that of said measured current for an equal time period as said first portion and immediately preceding or immediately following the period during which said first portion is generated, and wherein in step (d) said output signal is the integrated value of said generated signal over a period equal to an integer number of one full cycle periods of said applied alternating current signal.
Claim 4
Dependent Claim
29 words
A method in accordance with claim 2 wherein said period overwhich said signal is integrated is in zero phase relationship with the period of said applied alternating current signal.
Claim 5
Dependent Claim
30 words
A method in accordance with claim 3 wherein an additional measurement takes place over an equal measurement period in quadrature phase with the period of said applied alternating current signal.
Claim 6
Dependent Claim
58 words
A method in accordance with claim 2 wherein additional measurements are made by applying a direct current signal to one of said wires and measuring the current on the one of said wires to which said direct current signal is applied for a measurement period equal to an integer multiple of 33.33 milliseconds or an integral multiple thereof.
Claim 7
Dependent Claim
19 words
A method in accordance with claim 2 wherein said applied alternating current signal is a 30 Hz sine wave.
Claim 8
Dependent Claim
16 words
A method in accordance with claim 5 wherein said measurement period is equal to 33.33 milliseconds.
Claim 9
Dependent Claim
30 words
A method in accordance with claim 5 wherein said period over which said signal is integrated is in zero phase relationship with the period of said applied alternating current signal.
Claim 10
Dependent Claim
30 words
A method in accordance with claim 5 wherein an additional measurement takes place over an equal measurement period in quadrature phase with the period of said applied alternating current signal.
Claim 11
Dependent Claim
177 words
Apparatus for testing the electrical characteristics of two wire telephone lines in an environment of electrical noise at a predominant frequency f 1 , comprising, means for generating an alternating current test signal at a frequency equal to 1/2 f 1 , or a submultiple of 1/2 f 1 or an odd harmonic of 1/2 f 1 but less than 250 Hz, means for applying said alternating current test signal to a selected one of said telephone wires, signal generating means for generating an electrical signal proportional to the current measurement on said selected telephone wire over a measurement period equal to an integer number of half cycle periods of said alternating current test signal and equal to an integer number of full cycle periods of f 1 , means for integrating the output signal from said signal generating means for said measurement period and providing an output signal representative of the value of said integrated signal as an indication of an electrical characteristic between the selected one of said wires and said point of potential reference.
Claim 12
Dependent Claim
177 words
Apparatus for testing the electrical characteristics of two wire telephone lines in an environment of electrical noise at a predominant frequency f 1 , comprising, means for generating an alternating current test signal at a frequency equal to 1/2 f 1 , or a submultiple of 1/2 f 1 or an odd harmonic of 1/2 f 1 but less than 250 Hz, means for applying said alternating current test signal to a selected one of said telephone wires, signal generating means for generating an electrical signal proportional to the current measurement on said selected telephone wire over a measurement period equal to an integer number of half cycle periods of said alternating current test signal and equal to an integer number of full cycle periods of f 1 , means for integrating the output signal from said signal generating means for said measurement period and providing an output signal representative of the value of said integrated signal as an indication of an electrical characteristic between the selected one of said wires and said point of potential reference.
Claim 13
Dependent Claim
92 words
Apparatus in accordance with claim 10 wherein said signal generating means generates an electrical signal proportional to the current measurement on said selected telephone wire over a measurement period equal to an integer number of full cycle periods of said alternating current test signal, and wherein said means includes means for reversing the polarity of said generated signal during alternate successive periods equal to one-half cycle period of said alternating current test signal to produce said measured current, with alternate half cycles being of reversed polarity from that of the measured current.
Claim 14
Dependent Claim
28 words
Apparatus in accordance with claim 11 wherein said measurement period is selected to be in 0° phase relationship with the period of said applied alternating current test signal.
Claim 15
Dependent Claim
28 words
Apparatus in accordance with claim 11 wherein said measurement period is selected to be in quadrature phase relationship with the period of said applied alternating current test signal.
Claim 16
Dependent Claim
29 words
Apparatus in accordance with claim 11 wherein said alternating current test signal is at a frequency of 30 Hz and said measurement period is selected to be 33.33 milliseconds.
Claim 17
Dependent Claim
28 words
Apparatus in accordance with claim 14 wherein said measurement period is selected to be in 0° phase relationship with the period of said applied alternating current test signal.
Claim 18
Dependent Claim
28 words
Apparatus in accordance with claim 14 wherein said measurement period is selected to be in quadrature phase relationship with the period of said applied alternating current test signal.
Claim 19
Dependent Claim
42 words
Apparatus in accordance with claim 11 and including additional reference signal means providing as an additional input to said integrating means a reference signal derived by full wave rectifying said alternating current test signal for a period equal to said measurement period.
Claim 20
Dependent Claim
84 words
Apparatus in accordance with claim 11 wherein said means for applying said alternating current test signal and said signal generating means are formed such that the alternating current test signal is applied as a voltage between a point of potential reference and said selected wire and said signal proportional to the measured current in the time said alternating current test signal is applied to said selected wire is provided as an output voltage signal between an output terminal and said point of potential reference.
Claim 21
Independent Claim
125 words
A method for testing an electrically conductive line in an environment where the predominant power distribution is at a frequency f 1 , to determine the electrical characteristics thereof, comprising the steps of: applying to said line a periodic electrical input of specified frequency f 2 to generate a signal, f 2 being 1/2 f 1 , a submultiple of 1/2 f 1 , or an odd harmonic of 1/2 f 1 , and providing an output signal proportional to the average value of said generated signal over a period equal to the length of an integer number of full cycles of f 1 and equal to the length of an integer number of half cycles of f 2 selected to make said average non-zero.
Claim 22
Independent Claim
125 words
A method for testing an electrically conductive line in an environment where the predominant power distribution is at a frequency f 1 , to determine the electrical characteristics thereof, comprising the steps of: applying to said line a periodic electrical input of specified frequency f 2 to generate a signal, f 2 being 1/2 f 1 , a submultiple of 1/2 f 1 , or an odd harmonic of 1/2 f 1 , and providing an output signal proportional to the average value of said generated signal over a period equal to the length of an integer number of full cycles of f 1 and equal to the length of an integer number of half cycles of f 2 selected to make said average non-zero.
Claim 23
Dependent Claim
41 words
The method of claim 19 wherein said period is equal to the length of an integer number of full cycles of f 2 , and the polarity of said generated signal is reversed during alternate half cycles of f 2 .
Claim 24
Dependent Claim
16 words
The method of claim 19 wherein said period is in zero phase relationship with said input.
Claim 25
Dependent Claim
37 words
The method of claim 21 further comprising the step of providing an additional output signal proportional to the average value of said generated signal over a said period which is in quadrature phase relationship with said input.
Claim 26
Dependent Claim
48 words
The method of claim 20 further comprising the steps of applying a direct current signal to said line to generate a further signal, and providing an output signal proportional to the average value of said further signal over a period equal to an integer multiple of 33.33 milliseconds.
Claim 27
Dependent Claim
13 words
The method of claim 19 wherein said input is a 30 Hz sinusoid.
Claim 28
Dependent Claim
11 words
The method of claim 24 wherein said period is 33.33 milliseconds.
Claim 29
Dependent Claim
12 words
The method of claim 19 wherein said line is a telephone line.
Claim 30
Dependent Claim
13 words
The method of claim 19 wherein said line comprises a plurality of wires.
Claim 31
Dependent Claim
14 words
The method of claim 19 wherein f 2 is no greater than 250 Hz.
Claim 32
Dependent Claim
30 words
The method of claim 19 wherein an integrator is used to provide as said output signal a signal proportional to the integrated value of said generated signal over said period.
Claim 33
Dependent Claim
44 words
The method of claim 19 wherein said input is applied as a voltage between a point of potential reference and a wire in said line, and said output signal is provided as a voltage between an output terminal and said point of potential reference.
Claim 34
Dependent Claim
129 words
Apparatus for testing an electrically conductive line in an environment where the predominant power distribution is at a frequency f 1 , to determine the electrical characteristics thereof, comprising: input circuitry means for applying to said line a periodic electrical input of specified frequency f 2 to generate a signal, f 2 being 1/2 f 1 , a submultiple of 1/2 f 1 , or an odd harmonic of 1/2 f 1 , and output circuitry means for providing an output signal proportional to the average value of said generated signal over a period equal to the length of an integer number of full cycles of f 1 and equal to the length of an integer number of half cycles of f 2 selected to make said average non-zero.
Claim 35
Dependent Claim
129 words
Apparatus for testing an electrically conductive line in an environment where the predominant power distribution is at a frequency f 1 , to determine the electrical characteristics thereof, comprising: input circuitry means for applying to said line a periodic electrical input of specified frequency f 2 to generate a signal, f 2 being 1/2 f 1 , a submultiple of 1/2 f 1 , or an odd harmonic of 1/2 f 1 , and output circuitry means for providing an output signal proportional to the average value of said generated signal over a period equal to the length of an integer number of full cycles of f 1 and equal to the length of an integer number of half cycles of f 2 selected to make said average non-zero.
Claim 36
Dependent Claim
41 words
The apparatus of claim 31 wherein said period is equal to the length of an integer number of full cycles of f 2 , and the polarity of said generated signal is reversed during alternate half cycles of f 2 .
Claim 37
Dependent Claim
16 words
The apparatus of claim 31 wherein said period is in zero phase relationship with said input.
Claim 38
Dependent Claim
36 words
The apparatus of claim 33 further comprising means for providing an additional output signal proportional to the average value of said generated signal over a said period which is in quadrature phase relationship with said input.
Claim 39
Dependent Claim
49 words
The apparatus of claim 32 further comprising means for applying a direct current signal to said line to generate a further signal, and means for providing an output signal proportional to the average value of said further signal over a period equal to an integer multiple of 33.33 milliseconds.
Claim 40
Dependent Claim
13 words
The apparatus of claim 31 wherein said input is a 30 Hz sinusoid.
Claim 41
Dependent Claim
11 words
The apparatus of claim 36 wherein said period is 33.33 milliseconds.
Claim 42
Dependent Claim
12 words
The apparatus of claim 31 wherein said line is a telephone line.
Claim 43
Dependent Claim
13 words
The apparatus of claim 31 wherein said line comprises a plurality of wires.
Claim 44
Dependent Claim
14 words
The apparatus of claim 31 wherein f 2 is no greater than 250 Hz.
Claim 45
Dependent Claim
29 words
The apparatus of claim 31 further comprising an integrator to provide as said output signal a signal proportional to the integrated value of said generated signal over said period.
Claim 46
Dependent Claim
56 words
The apparatus of claim 31 wherein said input circuitry means includes means for providing said input as a voltage between a point of potential reference and a wire in said line, and said output circuitry means includes means for providing said output signal as a voltage between an output terminal and said point of potential reference.
Claim 47
Dependent Claim
21 words
A method in accordance with claim 1 wherein all said integer numbers are one and said specified frequency is 30 Hz.
Claim 48
Dependent Claim
20 words
Apparatus in accordance with claim 10 wherein all said integer numbers are one and said specified frequency is 30 Hz.
Claim 49
Dependent Claim
20 words
A method in accordance with claim 19 wherein all said integer numbers are one and f 2 is 30 Hz.
Claim 50
Dependent Claim
19 words
Apparatus in accordance with claim 31 wherein all said integer numbers are one and f 2 is 30 Hz.
Claim 51
Dependent Claim
11 words
The apparatus of claim 38 wherein f 1 is 60 Hz.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-09-11 | 1982-03-13 | 1982-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-11 | 1986-03-13 | 1986-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-11 | 1990-03-13 | 1990-09-12 | $7700.00 | Window Closed / Lapsed |