US3798432A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Measurement of pressure ratio
Assignee: Plessey Handel und Investments AG
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Filing: 1972-07-24
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Granted: 1974-03-19
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Expires: 1992-07-24
Abstract
Abstract Apparatus for evaluating width-modulated pulse waveforms, more particularly fluidic pulse waveforms which are obtained at the output of a substantially symmetrically constructed two-way switching device, wherein the evaluating means are arranged to form the algebraic sum of two outputs respectively obtained at the two outlets of the said switching device with the sign of one of these outputs reversed, and to determine the pulse width-tocycle ratio, hereinafter called the duty ratio, of the output waveform at a level halfway between the minimum and maximum levels of the waveform thus obtained.
Inventors
- 👤 P Dobson
- 👤 D Wyman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 18:30
CPC Classifications
F; F15; F15C; F15C1/00; F15C1/22; H; H03; H03K; H03K9/00; H03K9/08
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
92 words
Apparatus for evaluating width-modulated pulse waveforms, more particularly fluidic pulse waveforms, which are obtained at the two outlets of a substantially symmetrically constructed twoway switching device, which comprises means arranged to form, as a composite waveform, the algebraic sum of the outputs respectively obtained at the two outlets of the said switching device with the sign of one of these outputs reversed, and means operative to determine the pulse width-to-cycle ratio, hereinafter called the duty ratio, of the said composite waveform at a level halfway between the minimum and maximum levels thereof.
Claim 2
Dependent Claim
92 words
Apparatus for evaluating width-modulated pulse waveforms, more particularly fluidic pulse waveforms, which are obtained at the two outlets of a substantially symmetrically constructed twoway switching device, which comprises means arranged to form, as a composite waveform, the algebraic sum of the outputs respectively obtained at the two outlets of the said switching device with the sign of one of these outputs reversed, and means operative to determine the pulse width-to-cycle ratio, hereinafter called the duty ratio, of the said composite waveform at a level halfway between the minimum and maximum levels thereof.
Claim 3
Dependent Claim
30 words
Apparatus as claimed in claim 1, for evaluating a pulse-width-modulated fluidic pressure waveform, wherein such pulse-width-modulated fluidic-pressure waveform is, for the purpose of its evaluation, converted into an electrical waveform.
Claim 4
Dependent Claim
75 words
Apparatus as claimed in claim 1 for evaluating a pulse-width-modulated fluidic pressure waveform, wherein means are provided which convert the pressure at each of the two outlets of the said switching device individually into an electrical waveform, and means which algebraically add, with reversed sign, the electrical waveform obtained by conversion of the pressure waveform at one of the outlets to the electrical waveform obtained by conversion of the pressure waveform at the other outlet.
Claim 5
Dependent Claim
134 words
Apparatus as cLaimed in claim 2, wherein the electrical waveform representing said algebraic sum is applied in parallel to two clamp circuits each arranged to produce a replica of the waveform clamped respectively to the upper and to the lower peak level of the waveform amplitude, and wherein the two outputs of these clamp circuits are applied to a load circuit so centre-tapped as to produce a replica of the waveform which is so clamped in its D-C level that its voltage passes through zero halfway between the upper and lower peaks of the amplitude of the waveform, the output from said centre tapping and a zero voltage-level reference being applied to a final evaluator circuit responsive to the times and directions of the zero passages of the waveform obtained at said centre tapping.
Claim 6
Dependent Claim
99 words
Apparatus as claimed in claim 2, wherein the electrical waveform representing said algebraic sum is applied in parallel to two peak-voltage detectors arranged to produce output voltages respectively corresponding to the upper and to the lower peak level of the said waveform, these output voltages being respectively applied to the two ends of a centre-tapped load circuit to produce at the centre tapping a reference voltage-level, this reference voltage-level and the said waveform being applied to a final evaluator circuit responsive to the times and directions of the passages of the voltage of said waveform through said reference voltage-level.
Claim 7
Dependent Claim
139 words
An electrical circuit for evaluating the duty ratio of a pulse-width modulated periodic electrical waveform, wherein the waveform is applied in parallel to two clamp circuits each arranged to produce a replica of the waveform clamped respectively to the upper and to the lower peak level of the waveform amplitude, and wherein the two outputs of these clamp circuits are applied to a load circuit so centre-tapped as to produce a further replica of the waveform which is so clamped in its D-C level that its voltage passes through zero halfway between the upper and lower peaks of the amplitude of the waveform, the output from said centre tapping and a zero-voltage level reference being applied to a final evaluator circuit responsive to the times and directions of the zero passages of the waveform obtained at said centre tapping.
Claim 8
Dependent Claim
139 words
An electrical circuit for evaluating the duty ratio of a pulse-width modulated periodic electrical waveform, wherein the waveform is applied in parallel to two clamp circuits each arranged to produce a replica of the waveform clamped respectively to the upper and to the lower peak level of the waveform amplitude, and wherein the two outputs of these clamp circuits are applied to a load circuit so centre-tapped as to produce a further replica of the waveform which is so clamped in its D-C level that its voltage passes through zero halfway between the upper and lower peaks of the amplitude of the waveform, the output from said centre tapping and a zero-voltage level reference being applied to a final evaluator circuit responsive to the times and directions of the zero passages of the waveform obtained at said centre tapping.
Claim 9
Dependent Claim
50 words
An electrical circuit as claimed in claim 6, wherein said final evaluator comprises a high-gain differential amplifier arranged to produce an amplifier output which changes abruptly from saturation voltage in one direction to saturation voltage in the opposite direction at each zero passage of said further replica of the waveform.
Claim 10
Dependent Claim
66 words
An electrical circuit as claimed in claim 7, wherein the output of said high-gain differential amplifier is applied to an electronic switch connected to a constant voltage supply to produce a rectangular waveform changing, between zero voltage and the constant voltage of said supply, at each crossing of the reference-voltage level by the said further replica waveform, this rectangular waveform being applied to an averaging amplifier.
Claim 11
Dependent Claim
106 words
An electrical circuit for evaluating the duty ratio of a pulse-width modulted periodic electrical waveform, wherein the said waveform is applied in parallel to two peak-voltage detectors arranged to produce output voltages respectively corresponding to the upper and to the lower peak level of the said waveform, these output voltages being respectively applied to the two ends of a centre-tapped load circuit to produce at the centre tapping a reference voltage-level, this reference voltage level and the said waveform being applied to a final evaluator circuit responsive to the times and directions of the passages of the said voltage of said waveform through said reference voltage-level.
Claim 12
Dependent Claim
106 words
An electrical circuit for evaluating the duty ratio of a pulse-width modulted periodic electrical waveform, wherein the said waveform is applied in parallel to two peak-voltage detectors arranged to produce output voltages respectively corresponding to the upper and to the lower peak level of the said waveform, these output voltages being respectively applied to the two ends of a centre-tapped load circuit to produce at the centre tapping a reference voltage-level, this reference voltage level and the said waveform being applied to a final evaluator circuit responsive to the times and directions of the passages of the said voltage of said waveform through said reference voltage-level.
Claim 13
Dependent Claim
70 words
An electrical circuit as claimed in claim 9, wherein said final evaluator circuit comprises a high-gain differential amplifier for comparison of said reference - voltage level with the momentary voltage of the said waveform, so that the sign of the output of the differential amplifiEr changes each time the momentary voltage of the said waveform crosses a voltage-level halfway between the upper and lower voltage peaks of the said waveform.
Claim 14
Dependent Claim
63 words
An electrical circuit as claimed in claim 10, wherein the output of said high-gain differential amplifier is applied to an electronic switch connected to a constant-voltage supply to produce a rectangular waveform changing, between zero voltage and the constant voltage of said supply, at each crossing of the said waveform with said reference level, this rectangular waveform being applied to an averaging amplifier.
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) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |