Patent US2730962A successfully refreshed from Google Patents.
US4093871A
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US
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Correction circuit
Assignee: PC Compteurs Ltd
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Filing: 1976-10-06
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Granted: 1978-06-06
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Expires: 1996-10-06
Abstract
Abstract A correction circuit for correcting the frequency of the output pulses produced by a gas flowmeter in dependence on the temperature of the gas comprises a control input for receiving a voltage representative of the difference between the temperature of the gas and a reference temperature. A voltage-controlled oscillator, operative during fixed short periods initiated by each flowmeter pulse, produces auxiliary pulses at a rate dependent on the voltage at the control input, and the auxiliary pulses are counted in a counter. Each time the counter counts a predetermined number of auxiliary pulses, it produces a signal which either blocks one flowmeter pulse or adds an additional pulse to the flowmeter pulses, in dependence on the polarity of the temperature difference. The correction circuit also includes a power supply which continuously energizes only a first portion of the circuit, such first portion consuming a relatively small proportion of the power requirements of the circuit, and switching means connected to the power supply and responsive to flowmeter output pulses to energize the remainder of the circuit for a relatively short period, thereby to reduce the total power requirements of the circuit. Also disclosed is a test circuit to cooperate with such a correction circuit including an oscillator for producing test pulses of predetermined frequency, a switch for applying the test pulses to the correction circuit instead of pulses produced by the flowmeter output, and a counter arranged to count the number of pulses between either two successive adding operations or two successive blocking operations.
Inventors
- 👤 George Arthur Plumb
- 👤 John Leo Thomas Bushell
- 👤 Patrick Louis Radford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:14
CPC Classifications
G; G01; G01F; G01F15/00; G01F15/02; G01F15/04; G01F15/043; G01F15/046; G01F15/022; G01F15/024
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
378 words
A correction circuit for correcting the output signal produced by a fluid flowmeter which produces an electrical pulse output signal at a pulse repetition rate which is representative of the volumetric flow rate of the fluid whose flow rate is being measured by the flowmeter, said correction being effected in dependence upon at least one parameter of said fluid, the circuit comprising: a first input for receiving the output signal produced by the flowmeter, a second input for receiving an input signal representative of the magnitude of said parameter, first circuit means responsive to the flowmeter output signal at the first input to generate a first pulse train at a first average pulse repetition rate which is dependent upon said pulse repetition rate of the flowmeter output signal, a difference circuit responsive to the input signal at the second input to generate an auxiliary signal whose magnitude is dependent upon the difference between the magnitude of said parameter and a reference magnitude of said parameter, means responsive to said first average pulse repetition rate and to the magnitude of the auxiliary signal to increase the number of pulses in the first pulse train by adding auxiliary pulses thereto at a rate dependent upon the magnitude of said difference when said difference is of one polarity, and to decrease the number of pulses in the first pulse train by blocking a fraction thereof at a rate dependent upon the magnitude of said difference when said difference is of the other polarity, whereby the pulse adding and blocking means produces an output pulse train at a second average pulse repetition rate which is representative of the volumetric flow rate of the fluid corrected for variations in said parameter, an oscillator for producing test pulses of predetermined frequency, switch means for applying the test pulses to the first circuit means in place of the flowmeter output signal, and counter means arranged to count the number of pulses produced by the pulse adding and blocking means during an internal defined between a selected one of two successive adding operations and two succesive blocking operations of the pulse adding and blocking means, whereby the count in said counter means at the end of said interval is indicative of the magnitude of said difference.
Claim 2
Dependent Claim
378 words
A correction circuit for correcting the output signal produced by a fluid flowmeter which produces an electrical pulse output signal at a pulse repetition rate which is representative of the volumetric flow rate of the fluid whose flow rate is being measured by the flowmeter, said correction being effected in dependence upon at least one parameter of said fluid, the circuit comprising: a first input for receiving the output signal produced by the flowmeter, a second input for receiving an input signal representative of the magnitude of said parameter, first circuit means responsive to the flowmeter output signal at the first input to generate a first pulse train at a first average pulse repetition rate which is dependent upon said pulse repetition rate of the flowmeter output signal, a difference circuit responsive to the input signal at the second input to generate an auxiliary signal whose magnitude is dependent upon the difference between the magnitude of said parameter and a reference magnitude of said parameter, means responsive to said first average pulse repetition rate and to the magnitude of the auxiliary signal to increase the number of pulses in the first pulse train by adding auxiliary pulses thereto at a rate dependent upon the magnitude of said difference when said difference is of one polarity, and to decrease the number of pulses in the first pulse train by blocking a fraction thereof at a rate dependent upon the magnitude of said difference when said difference is of the other polarity, whereby the pulse adding and blocking means produces an output pulse train at a second average pulse repetition rate which is representative of the volumetric flow rate of the fluid corrected for variations in said parameter, an oscillator for producing test pulses of predetermined frequency, switch means for applying the test pulses to the first circuit means in place of the flowmeter output signal, and counter means arranged to count the number of pulses produced by the pulse adding and blocking means during an internal defined between a selected one of two successive adding operations and two succesive blocking operations of the pulse adding and blocking means, whereby the count in said counter means at the end of said interval is indicative of the magnitude of said difference.
Claim 3
Dependent Claim
26 words
A correction circuit as claimed in claim 1, wherein said predetermined frequency is higher than the highest anticipated pulse repetition rate of the flowmeter output signal.
Claim 4
Dependent Claim
92 words
A correction circuit as claimed in claim 1, including generating means responsive to the auxiliary signal from said difference circuit to generate an oscillatory signal having an average frequency dependent upon the magnitude of said difference, and additional counter means responsive to each pulse of said first pulse train to count cycles of said oscillatory signal occurring within a period of predetermined duration initiated by that pulse and arranged to produce an overflow signal each time it reaches a predetermined full-house count, wherein said interval is defined between two successive overflow signals.
Claim 5
Dependent Claim
256 words
A correction circuit for correcting the output signal produced by a fluid flowmeter which produces an electrical pulse output signal whose pulse repetition rate is representative of the volumetric flow rate of the fluid whose flow rate is being measured by the flowmeter, said correction being effected in dependence upon at least one parameter of said fluid, the circuit comprising: a first input for receiving the output signal produced by the flowmeter, a second input for receiving an input signal representative of the magitude of said parameter, first circuit means responsive to the flowmeter output signal at the first input to generate a first pulse train whose average pulse repetition rate is dependent upon the pulse repetition rate of the flowmeter output signal, means responsive to the input signal at the second input to modify the pulse repetition rate of the first pulse train in dependence upon the magnitude of said parameter so as to produce an output pulse train whose average pulse repetition rate is representative of the volumetric flow rate of the fluid corrected for variations in said parameter, a power supply which, in operation, is continuously connected to energise a first portion of the circuit, said first portion being arranged to consume a relatively small proportion of the power required by the circuit, and switching means connected to the power supply and responsive to each pulse of the flowmeter output signal to energise the remainder of the circuit for a relatively short period, whereby to reduce the total power required by the circuit.
Claim 6
Dependent Claim
256 words
A correction circuit for correcting the output signal produced by a fluid flowmeter which produces an electrical pulse output signal whose pulse repetition rate is representative of the volumetric flow rate of the fluid whose flow rate is being measured by the flowmeter, said correction being effected in dependence upon at least one parameter of said fluid, the circuit comprising: a first input for receiving the output signal produced by the flowmeter, a second input for receiving an input signal representative of the magitude of said parameter, first circuit means responsive to the flowmeter output signal at the first input to generate a first pulse train whose average pulse repetition rate is dependent upon the pulse repetition rate of the flowmeter output signal, means responsive to the input signal at the second input to modify the pulse repetition rate of the first pulse train in dependence upon the magnitude of said parameter so as to produce an output pulse train whose average pulse repetition rate is representative of the volumetric flow rate of the fluid corrected for variations in said parameter, a power supply which, in operation, is continuously connected to energise a first portion of the circuit, said first portion being arranged to consume a relatively small proportion of the power required by the circuit, and switching means connected to the power supply and responsive to each pulse of the flowmeter output signal to energise the remainder of the circuit for a relatively short period, whereby to reduce the total power required by the circuit.
Claim 7
Dependent Claim
20 words
A correction circuit as claimed in claim 4, wherein the first portion of the circuit includes the first circuit means.
Claim 8
Dependent Claim
104 words
A correction circuit as claimed in claim 5, wherein the first circuit means comprises a delay arranged to delay the flowmeter output pulses for a relatively short period, and first pulse producing means responsive to the leading edge of each delayed flowmeter output pulse to produce a corresponding pulse of relatively short duration, the output pulses produced by said first pulse producing means constituting the first pulse train, and the switching means is arranged to energise the remainder of the circuit between the leading edge of each flowmeter pulse and the trailing edge of the corresponding pulse produced by the first pulse producing means.
Claim 9
Dependent Claim
43 words
A correction circuit as claimed in claim 6, wherein the first pulse producing means comprises a first monostable circuit, and the second circuit means comprises a second monostable circuit connected to be triggered by the trailing edge of each delayed flowmeter output pulse.
Claim 10
Dependent Claim
267 words
A correction circuit for correcting the output signal produced by a fluid flowmeter which produces an electrical pulse output signal whose pulse repetition rate is representative of the volumetric flow rate of the fluid whose flow rate is being measured by the flowmeter, said correction being effected in dependence upon at least one parameter of said fluid, the circuit comprising: a first input for receiving the output signal produced by the flowmeter, a second input for receiving an input signal representative of the magnitude of said parameter, first circuit means responsive to the flowmeter output signal at the first input to generate a first pulse train whose average pulse repetition rate is dependent on the pulse repetition rate of the flowmeter output signal, second circuit means responsive to the input signal at the second input to generate a second pulse train whose average pulse repetition rate is dependent on the magnitude of said parameter, means for combining said first and second pulse trains so as to produce an output pulse train whose average pulse repetitive rate is representative of the volumetric flow rate of the fluid corrected for variations in said parameter, a power supply which, in operation, is continuously connected to energize a first portion of the circuit, said first portion being arranged to consume a relatively small proportion of the power required by the circuit, and switching means connected to the power supply and responsive to each pulse of the flowmeter output signal to energize the remainder of the circuit for a relatively short period, whereby to reduce to total power required by the circuit.
Claim 11
Dependent Claim
267 words
A correction circuit for correcting the output signal produced by a fluid flowmeter which produces an electrical pulse output signal whose pulse repetition rate is representative of the volumetric flow rate of the fluid whose flow rate is being measured by the flowmeter, said correction being effected in dependence upon at least one parameter of said fluid, the circuit comprising: a first input for receiving the output signal produced by the flowmeter, a second input for receiving an input signal representative of the magnitude of said parameter, first circuit means responsive to the flowmeter output signal at the first input to generate a first pulse train whose average pulse repetition rate is dependent on the pulse repetition rate of the flowmeter output signal, second circuit means responsive to the input signal at the second input to generate a second pulse train whose average pulse repetition rate is dependent on the magnitude of said parameter, means for combining said first and second pulse trains so as to produce an output pulse train whose average pulse repetitive rate is representative of the volumetric flow rate of the fluid corrected for variations in said parameter, a power supply which, in operation, is continuously connected to energize a first portion of the circuit, said first portion being arranged to consume a relatively small proportion of the power required by the circuit, and switching means connected to the power supply and responsive to each pulse of the flowmeter output signal to energize the remainder of the circuit for a relatively short period, whereby to reduce to total power required by the circuit.
References Cited (Backward Citations)
US3610898A
Cited
US3614892A
Cited
US3688573A
Cited
US3691838A
Cited
US3745827A
Cited
US3905229A
Cited
US3823310A
Cited
US3978727A
Cited
US4005603A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-05 | 1981-12-05 | 1982-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-05 | 1985-12-05 | 1986-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-05 | 1989-12-05 | 1990-06-06 | $7700.00 | Window Closed / Lapsed |