Patent US3965418A successfully refreshed from Google Patents.
US3965418A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone system testing apparatus and techniques utilizing central measuring equipment with a plurality of remote test stations
Assignee: Anritsu Co
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Filing: 1975-03-06
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Granted: 1976-06-22
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Expires: 1995-03-06
Abstract
Abstract Centralized telephone circuit testing equipment with receptacles for selectively receiving a wide variety of electronic circuit modules, various modules being provided to make the equipment capable of performing a large number of commonly employed telephone tests. A scanning system is disclosed as part of the central measuring equipment for determining which of a plurality of remote testing stations has requested access to the central measuring equipment, one requesting remote station at a time being given complete control over a test function of the central measuring equipment for conducting tests on a telephone trunk. Improvements are also disclosed in the individual test function electronic circuit modules, including common circuits for use in measuring both signal level and circuit noise, a logarithmic analog-to-digital convertor capable of handling signals that cross zero dBm in level, round off digital display circuits to improve accuracy of the display and to aid in calibrating the instruments, and an improved frequency measuring circuit.
Inventors
- 👤 Paul R. Bauer
- 👤 Duane E. Dunwoodie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:05
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/22; H04M3/26; H04M3/28
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
234 words
An electronic circuit for selectively measuring either signal level or noise level from a communication circuit, comprising: a single visual display device, an input for connection to said communication circuit under test, control means responsive to a control input for establishing either signal level or noise level states, an amplifier responsive to the input, said amplifier being switchable between two distinct amplification levels and connected to said control means to have a different amplification when said control means is in its noise state than when said control means is in its signal level state, a filter circuit for modifying the frequency response of the amplified signal, said filter circuit being switchable between at least two different frequency response curves in response to the state of said control means, said filter circuit having a different bandwidth when said control means is in its noise state than when said control means is in its signal level state, means receiving the output of said filter circuit for detecting said output in a manner to form a DC signal output, said detector being responsive to said control means in a manner to be a first type detector when said control means is in its signal level state and to be a second type detector when said control means is in its noise state, and means receiving the DC output of said detector for driving said single visual display.
Claim 2
Dependent Claim
234 words
An electronic circuit for selectively measuring either signal level or noise level from a communication circuit, comprising: a single visual display device, an input for connection to said communication circuit under test, control means responsive to a control input for establishing either signal level or noise level states, an amplifier responsive to the input, said amplifier being switchable between two distinct amplification levels and connected to said control means to have a different amplification when said control means is in its noise state than when said control means is in its signal level state, a filter circuit for modifying the frequency response of the amplified signal, said filter circuit being switchable between at least two different frequency response curves in response to the state of said control means, said filter circuit having a different bandwidth when said control means is in its noise state than when said control means is in its signal level state, means receiving the output of said filter circuit for detecting said output in a manner to form a DC signal output, said detector being responsive to said control means in a manner to be a first type detector when said control means is in its signal level state and to be a second type detector when said control means is in its noise state, and means receiving the DC output of said detector for driving said single visual display.
Claim 3
Dependent Claim
77 words
The circuit of claim 1 wherein said driving means includes means for shifting the signal prior to its application to the visual display that a zero reading occurs on the visual display in response to one input level at said input when said control means is in its signal level state and a zero reading occurs in response to a second distinct input level at the input when said control means is in its noise level state.
Claim 4
Dependent Claim
25 words
The circuit of claim 2 wherein said one and said second input levels of said driving means are zero dBm. and minus ninty dBm., respectively.
Claim 5
Dependent Claim
26 words
The electronic circuit of claim 1 wherein said first type of detector is an average type and said second type of detector is a r.m.s. type.
Claim 6
Dependent Claim
59 words
The electronic circuit of claim 1 wherein said single visual display is a multi-digital display device and wherein said display driving means includes means for blanking display of the least significant digit when said control means is in its noise state while permitting display of the least significant digit when said control means is in its signal level state.
Claim 7
Dependent Claim
51 words
The electronic circuit according to claim 1 wherein said display driving means additionally includes means responsive to the state of said control means for updating the single visual display less often when said control means is in its noise state than when said control means is in its signal level state.
Claim 8
Dependent Claim
21 words
The electronic circuit according to claim 1 wherein said control input to said control means is manually established by an operator.
Claim 9
Dependent Claim
72 words
The electronic circuit according to claim 1 wherein said control input to said control means includes automatic means sensing the level inputted to said circuit for developing a control input to said control means to switch into its signal level state if the circuit input is in excess of a predetermined amount and to switch said control means into its noise level state if said input is less than a predetermined amount.
References Cited (Backward Citations)
US3652934A
Cited
US3790886A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-22 | 1979-12-22 | 1980-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-22 | 1983-12-22 | 1984-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-22 | 1987-12-22 | 1988-06-22 | $7700.00 | Window Closed / Lapsed |