US4678345A
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Equivalent time pseudorandom sampling system
Assignee: Tektronix Inc
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Filing: 1986-05-01
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Granted: 1987-07-07
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Expires: 2006-05-01
Abstract
Abstract An equivalent time pseudorandom sampling system samples a repetitive waveform within each of several narrow acquisition windows bounding repetitive sections of the waveform in order to obtain equivalent time sample data characterizing the shape of the waveform included within the acquisition windows. The period between successive triggering events is measured and sampling is delayed following an initiating triggering event by delay time adjusted according to the measured period so as to maximize the probability that sampling will occur within an acquisition window. The time difference between samples and subsequent triggering event is measured with high accuracy and resolution utilizing a time interval measurement system based on a dual vernier interpolation.
Inventors
- 👤 Agoston Agoston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:47
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/25; G01R19/255; G01R13/00; G01R13/20; G01R13/22; G01R13/32; G01R13/34; G04; G04F; G04F5/00
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
171 words
A method for measuring a time interval between first and second events comprising the steps of: periodically generating a reference signal; triggering first and second periodic signals on occurrence of said first and second events, respectively; sampling said first and second periodic signals on each occurrence of said reference signal and determining the magnitude of each signal sample; counting cycles of said first periodic signal occurring after triggering said first periodic signal and before the sampled magnitude of said first periodic signal crosses a predetermined level, thereby producing a first count; counting cycles of said second periodic signal occurring after triggering said second periodic signal and before the sampled magnitude of said second periodic signal crosses said predetermined level, thereby producing a second count; and counting occurrences of said reference signal generated between a first moment when said sampled magnitude of said first periodic signal crosses said predetermined level and a second moment when said sampled magnitude of said second periodic signal crosses said predetermined level, thereby producing a third count.
Claim 2
Independent Claim
171 words
A method for measuring a time interval between first and second events comprising the steps of: periodically generating a reference signal; triggering first and second periodic signals on occurrence of said first and second events, respectively; sampling said first and second periodic signals on each occurrence of said reference signal and determining the magnitude of each signal sample; counting cycles of said first periodic signal occurring after triggering said first periodic signal and before the sampled magnitude of said first periodic signal crosses a predetermined level, thereby producing a first count; counting cycles of said second periodic signal occurring after triggering said second periodic signal and before the sampled magnitude of said second periodic signal crosses said predetermined level, thereby producing a second count; and counting occurrences of said reference signal generated between a first moment when said sampled magnitude of said first periodic signal crosses said predetermined level and a second moment when said sampled magnitude of said second periodic signal crosses said predetermined level, thereby producing a third count.
Claim 3
Dependent Claim
25 words
The method according to claim 1 wherein said first and second periodic signals are of frequencies which differ from the frequency of said reference signal.
Claim 4
Dependent Claim
23 words
The method according to claim 2 further comprising the step of computing said time interval according to said first, second and third counts.
Claim 5
Independent Claim
73 words
A method for sampling a repetitive waveform, the method comprising the steps of: measuring a first time interval between first and second triggering events in said repetitive waveform; and generating in delayed response to a third triggering event in said repetitive waveform a strobe signal for initiating sampling of said repetitive waveform, the delay between said third triggering event and generation of said strobe signal being adjusted according to said measured time interval.
Claim 6
Independent Claim
73 words
A method for sampling a repetitive waveform, the method comprising the steps of: measuring a first time interval between first and second triggering events in said repetitive waveform; and generating in delayed response to a third triggering event in said repetitive waveform a strobe signal for initiating sampling of said repetitive waveform, the delay between said third triggering event and generation of said strobe signal being adjusted according to said measured time interval.
Claim 7
Dependent Claim
25 words
The method according to claim 4 wherein said delay is adjusted to equal the sum of said measured first time interval and a predetermined interval.
Claim 8
Dependent Claim
25 words
The method according to claim 4 wherein said delay is adjusted to equal the difference between said measured first time interval and a predetermined interval.
Claim 9
Dependent Claim
29 words
The method according to claim 4 further comprising the step of measuring a second time interval between said strobe signal and a fourth triggering event in said repetitive waveform.
Claim 10
Dependent Claim
168 words
The method according to claim 7 wherein the step of measuring said second time interval comprises the substeps of: periodically generating a reference signal; triggering a first periodic signal on occurrence of said strobe signal and triggering a second periodic signal on occurrence of said fourth triggering event; sampling said first and second periodic signals on each occurrence of said reference signal and determining the magnitude of each signal sample; counting cycles of said first periodic signal occurring after triggering said first periodic signal and before the sample magnitude of said first periodic signal crosses a predetermined level; counting cycles of said second periodic signal occurring after triggering said second periodic signal and before the sample magnitude of said second periodic signal crosses a predetermined level; and counting occurrences of said reference signal generated between a first moment when said sampled magnitude of said first periodic signal crosses said predetermined level and a second moment when said sampled magnitude of said second periodic signal crosses said predetermined level.
Claim 11
Independent Claim
158 words
An apparatus for measuring a time interval between first and second events comprising: a reference oscillator for periodically generating a reference signal; a first triggerable oscillator for generating a first periodic signal triggered by said first event; a second triggerable oscillator for generating a second periodic signal triggered by said second event; means for sampling said first and second periodic signals on each occurrence of said reference signal; means for counting cycles of said first periodic signal occurring before the sampled magnitude of said first periodic signal crosses a predetermined level; means for counting cycles of said second periodic signal occurring before the sampled magnitude of said second periodic signal crosses a predetermined level; and means for counting occurrences of said reference signal generated between a first moment when said sampled magnitude of said first periodic signal crosses said predetermined level and a second moment when said sampled magnitude of said second periodic signal crosses said predetermined level.
Claim 12
Independent Claim
158 words
An apparatus for measuring a time interval between first and second events comprising: a reference oscillator for periodically generating a reference signal; a first triggerable oscillator for generating a first periodic signal triggered by said first event; a second triggerable oscillator for generating a second periodic signal triggered by said second event; means for sampling said first and second periodic signals on each occurrence of said reference signal; means for counting cycles of said first periodic signal occurring before the sampled magnitude of said first periodic signal crosses a predetermined level; means for counting cycles of said second periodic signal occurring before the sampled magnitude of said second periodic signal crosses a predetermined level; and means for counting occurrences of said reference signal generated between a first moment when said sampled magnitude of said first periodic signal crosses said predetermined level and a second moment when said sampled magnitude of said second periodic signal crosses said predetermined level.
Claim 13
Independent Claim
75 words
An apparatus for timing sampling of a repetitive waveform comprising: means for measuring a first time interval between first and second triggering events in said repetitive waveform; and means for generating in delayed response to a third triggering event in said repetitive waveform a strobe signal for initiating sampling of said repetitive waveform, the delay between said third triggering event and generation of said strobe signal being set according to said measured first time interval.
Claim 14
Independent Claim
75 words
An apparatus for timing sampling of a repetitive waveform comprising: means for measuring a first time interval between first and second triggering events in said repetitive waveform; and means for generating in delayed response to a third triggering event in said repetitive waveform a strobe signal for initiating sampling of said repetitive waveform, the delay between said third triggering event and generation of said strobe signal being set according to said measured first time interval.
Claim 15
Dependent Claim
23 words
The apparatus according to claim 10 wherein said delay is set equal to said measured first time interval adjusted by a predetermined interval.
Claim 16
Dependent Claim
28 words
The apparatus according to claim 10 further comprising means for measuring a second time interval between said strobe signal and a fourth triggering event in said repetitive waveform.
Claim 17
Dependent Claim
178 words
The apparatus according to claim 12 wherein said means for measuring said second time interval comprises: means for periodically generating a reference signal; a first triggerable oscillator for generating a first periodic signal when triggered by said strobe signal; a second triggerable oscillator for generating a second periodic signal when triggered by said fourth triggering event; means for sampling said first and second periodic signals on each occurrence of said reference signal; means for counting cycles of said first periodic signal occurring after triggering of said first periodic signal and before the sampled magnitude of said first periodic signal crosses a predetermined level; means for counting cycles of said second periodic signal occurring after triggering of said second periodic signal and before the sampled magnitude of said second periodic signal crosses said predetermined level; and means for counting occurrences of said reference signal generated after a first moment when said sampled magnitude of said first periodic signal crosses said predetermined level and a second moment when said sampled magnitude of said second periodic signal crosses said predetermined level.
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) | 1990-07-06 | 1991-01-05 | 1991-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-06 | 1995-01-05 | 1995-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-06 | 1999-01-05 | 1999-07-07 | $7700.00 | Window Closed / Lapsed |