Patent US4041387A successfully refreshed from Google Patents.
US4041387A
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Apparatus and method for measuring the frequency of a sweeping signal
Assignee: HP Inc
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Filing: 1975-09-18
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Granted: 1977-08-09
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Expires: 1995-09-18
Abstract
Abstract A swept frequency measuring system is provided with an electronic counter for measuring the frequency of the sweeping signal from a sweeping signal generator, at a predetermined point in the sweep indicated by a marker. Upon the occurrence of a marker, the counter starts counting the frequency of the signal while the sweeping signal generator continues to sweep. After a predetermined interval, the counter stops counting for a second predetermined interval and, then, during a third predetermined interval counts down from the count made during the first interval. The resultant count remaining in the counter is an indication of the frequency of the sweeping signal at the marker, and this count is displayed in a digital display.
Inventors
- 👤 Rolf W. Dalichow
- 👤 Frederic W. Woodhull
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:59
CPC Classifications
G; G01; G01R; G01R23/00; G01R23/02; G01R23/10
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
146 words
A method for measuring the frequency of an output signal from a sweeping signal generator at a predetermined point in the sweep of the generator, the method comprising the steps of: receiving a start signal; counting the number of periods of the output signal during a first time interval in response to receipt of the start signal; stopping the counting during a second time interval subsequent to the first time interval; and counting the number of periods of the output signal during a third time interval subsequent to the second time interval and subtracting the number of periods of the output signal counted during the third time interval from the number of periods of the output signal counted during the first time interval, thereby producing a measurement number of counts indicative of the frequency of the output signal at the time the start signal was received.
Claim 2
Independent Claim
146 words
A method for measuring the frequency of an output signal from a sweeping signal generator at a predetermined point in the sweep of the generator, the method comprising the steps of: receiving a start signal; counting the number of periods of the output signal during a first time interval in response to receipt of the start signal; stopping the counting during a second time interval subsequent to the first time interval; and counting the number of periods of the output signal during a third time interval subsequent to the second time interval and subtracting the number of periods of the output signal counted during the third time interval from the number of periods of the output signal counted during the first time interval, thereby producing a measurement number of counts indicative of the frequency of the output signal at the time the start signal was received.
Claim 3
Dependent Claim
50 words
A method as in claim 1 further comprising the steps of: receiving a sweep signal from the sweeping signal generator; and comparing the sweep signal with a reference signal and generating the start signal when the value of the sweep signal is equal to the value of the reference signal.
Claim 4
Dependent Claim
59 words
A method as in claim 2 wherein the second and third time intervals are each one third the length of the first time interval and the frequency of the output signal at the time the start signal was received is equal to the measurement number of counts divided by two thirds of the length of the first time interval.
Claim 5
Independent Claim
146 words
An apparatus for measuring the frequency of an output signal from a sweeping signal generator at a predetermined point in the sweep of the sweeping signal generator, the apparatus comprising: a signal input circuit for receiving the output signal from the sweeping signal generator; start signal means for producing a start signal at a predetermined point in the sweep of the sweeping signal generator; and counter means connected to the signal input circuit and the start signal means for counting the number of periods of the output signal during first and third time intervals separated by a second time interval, and for subtracting the number of periods counted during the third time interval from the number of periods counted during the first time interval, producing thereby a number of counts indicative of the frequency of the output signal at the time the start signal was produced.
Claim 6
Independent Claim
146 words
An apparatus for measuring the frequency of an output signal from a sweeping signal generator at a predetermined point in the sweep of the sweeping signal generator, the apparatus comprising: a signal input circuit for receiving the output signal from the sweeping signal generator; start signal means for producing a start signal at a predetermined point in the sweep of the sweeping signal generator; and counter means connected to the signal input circuit and the start signal means for counting the number of periods of the output signal during first and third time intervals separated by a second time interval, and for subtracting the number of periods counted during the third time interval from the number of periods counted during the first time interval, producing thereby a number of counts indicative of the frequency of the output signal at the time the start signal was produced.
Claim 7
Dependent Claim
178 words
An apparatus as in claim 4 wherein the counter means comprises: a gate circuit; an up-down counter having a signal input connected to the gate circuit, an up-down input and an output; a timer having an input connected to the start signal circuit for starting the first time interval upon receipt of the start signal and an output for producing signals representing the beginning and end of the first, second and third time intervals; and a control circuit having an input connected to the timer output, a first output connected to the gate circuit and a second output connected to the up-down input for causing the gate circuit to open and the up-down counter to count up at the beginning of the first time interval, for causing the gate circuit to close at the beginning of the second time interval, for causing the gate circuit to open and the up-down counter to count down at the beginning of the third time interval, and for causing the gate circuit to close at the end of the third time interval.
Claim 8
Dependent Claim
72 words
An apparatus as in claim 5 wherein the start signal means comprises: a sweep signal input circuit for receiving a sweep signal from the sweeping signal generator; a reference signal circuit for providing a reference signal; and a comparator connected to the sweep signal input circuit and the reference signal circuit for producing the start signal at an output thereof when the sweep signal and the reference signal have a predetermined relationship.
Claim 9
Dependent Claim
60 words
An apparatus as in claim 6 wherein the second and third time intervals are one third the length of the first time interval and the frequency of the output signal at the time of the start signal is equal to the number of counts in the up-down counter divided by two thirds of the length of the first time interval.
Claim 10
Dependent Claim
32 words
An apparatus as in claim 6 further comprising a display circuit having an input connected to the up-down counter output for displaying a number indicative of the frequency of the output signal.
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) | 1980-08-08 | 1981-02-07 | 1981-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-08 | 1985-02-07 | 1985-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-08 | 1989-02-07 | 1989-08-09 | $7700.00 | Window Closed / Lapsed |