EP0471119A1
Expired / Lapsed
EP
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Waveform measurement
Assignee: Hewlett Packard Ltd
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Filing: 1990-08-14
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Granted: —
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Expires: 2010-08-14
Abstract
Abstract The characteristics of an a.c. waveform are determined by measuring the time interval between the instant when the waveform crosses a first reference threshold (12) and the instant when it crosses another threshold (14). The second threshold is varied to obtain a series of time interval measurements from which a point by point reconstruction of the waveform can be made. The technique has the advantage that it can be used to characterise waveforms whose arrival time is indeterminable.
Inventors
- 👤 Norman George Carder
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 18:58
CPC Classifications
G; G01; G01R; G01R29/00; G01R29/02; G01R29/027
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
56 words
A method of measuring the characteristics of an a.c. waveform characterised by measuring the time interval between the instant when the waveform level attains a reference level and an instant when the waveform level attains some other level, repeating the measurements for a plurality of said other levels, and reconstructing the waveform from said measured values.
Claim 2
Independent Claim
56 words
A method of measuring the characteristics of an a.c. waveform characterised by measuring the time interval between the instant when the waveform level attains a reference level and an instant when the waveform level attains some other level, repeating the measurements for a plurality of said other levels, and reconstructing the waveform from said measured values.
Claim 3
Dependent Claim
22 words
A method according to claim 1 characterised by including the step of obtaining several samples of each measurement and evaluating an average.
Claim 4
Dependent Claim
37 words
A method according to claim 1 or claim 2, wherein the time may be measured by starting a counter at the instant the reference level is attained and stopping said counter when the other level is attained.
Claim 5
Dependent Claim
29 words
A method according to claim 3, wherein the signal for stopping the counter is delayed to allow measurement of that part of the waveform prior to the reference level.
Claim 6
Dependent Claim
69 words
Apparatus for use in measuring the characteristics of a waveform characterised in that it comprises means (23, 24, 25) for sensing when a waveform attains a predetermined first level and for sensing when said waveform attains a variable second level, and means (35) for measuring the time interval between the instant when the waveform attains said predetermined first level and the instant when the waveform attains said second level.
Claim 7
Dependent Claim
69 words
Apparatus for use in measuring the characteristics of a waveform characterised in that it comprises means (23, 24, 25) for sensing when a waveform attains a predetermined first level and for sensing when said waveform attains a variable second level, and means (35) for measuring the time interval between the instant when the waveform attains said predetermined first level and the instant when the waveform attains said second level.
Claim 8
Dependent Claim
13 words
Apparatus according to claim 5, wherein the measuring means (35) comprises a counter.
Claim 9
Dependent Claim
20 words
Apparatus according to claim 5 or claim 6, wherein the sensing means (23, 24, 25) comprises one or more comparators.
References Cited (Backward Citations)
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