US3818340A
Expired / Lapsed
US
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Electronic watt-hour meter with digital output representing time-integrated input
Assignee: Yokogawa Electric Corp
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Filing: 1972-03-22
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Granted: 1974-06-18
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Expires: 1992-03-22
Abstract
Abstract An electronic meter, such as a watt-hour meter, arranged to process an input signal which has an amplitude varying instantaneously with time, such as a wattage signal, and to provide a digital output signal representing the time-integrated value of the input signal, for example, a digital output representing accumulated watt-hours of electrical power. The meter applies the time-varying input signal to a pulse width modulating means to convert the input signal into a pulse signal in which the pulse width varies in correspondence to the amplitude of the input signal. The modulated pulse signal drives a gating circuit which controls the application of a steady clock pulse signal from a generator to a pulse counting means providing a digital signal output representing the cumulative total of clock pulses applied thereto through the gating circuit. The gating circuit, in response to the modulated pulse signal, applies a proportion of the total clock pulses which corresponds in number to the time-integrated value of the input signal, thereby providing the desired digital watt-hour output.
Inventors
- 👤 K Yamaguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:53
CPC Classifications
G; G01; G01R; G01R21/00; G01R21/133; G06; G06J; G06J1/00; H; H03; H03M; H03M1/00; H03M1/12; H03M1/50
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
276 words
An electronic time-integrating meter, such as a watt-hour meter, arranged to process an input signal varying its amplitude instantaneously with time, and to provide an output signal digitally representing the integral of the input signal with respect to time, subsequent to a starting time serving as the lower limit of integration, comprising: pulse width modulating means for converting the input signal into a pulse signal in which the pulse width varies in correspondence to the amplitude of the input signal; and cumulative digital time measuring means responsive to the pulse width modulating means for digitally measuring pulse widths in said modulated pulse signal and for accumulating said digital pulse width measurements occurring subsequent to said starting time to provide a totalled digital number representing the integral of the input with respect to time with said starting time as the lower limit of integration, said cumulative digital time measuring means including: a clock pulse generator for generating a clock pulse signal with a constant pulse rate; pulse counting means for cumulatively counting the number of clock pulses applied thereto subsequent to said starting time and for providing a digital signal output indicating the cumulative number of clock pulses counted there subsequent to said starting time; and gating means responsive to the modulated pulse signal for applying to the counting means a portion of the clock pulse signal which corresponds to the widths of the pulses in the modulated pulse signal, whereby the total number of clock pulses applied to the counting means and indicated by the digital signal output is representative of the integral of the input signal with respect to time subsequent to said starting time.
Claim 2
Dependent Claim
276 words
An electronic time-integrating meter, such as a watt-hour meter, arranged to process an input signal varying its amplitude instantaneously with time, and to provide an output signal digitally representing the integral of the input signal with respect to time, subsequent to a starting time serving as the lower limit of integration, comprising: pulse width modulating means for converting the input signal into a pulse signal in which the pulse width varies in correspondence to the amplitude of the input signal; and cumulative digital time measuring means responsive to the pulse width modulating means for digitally measuring pulse widths in said modulated pulse signal and for accumulating said digital pulse width measurements occurring subsequent to said starting time to provide a totalled digital number representing the integral of the input with respect to time with said starting time as the lower limit of integration, said cumulative digital time measuring means including: a clock pulse generator for generating a clock pulse signal with a constant pulse rate; pulse counting means for cumulatively counting the number of clock pulses applied thereto subsequent to said starting time and for providing a digital signal output indicating the cumulative number of clock pulses counted there subsequent to said starting time; and gating means responsive to the modulated pulse signal for applying to the counting means a portion of the clock pulse signal which corresponds to the widths of the pulses in the modulated pulse signal, whereby the total number of clock pulses applied to the counting means and indicated by the digital signal output is representative of the integral of the input signal with respect to time subsequent to said starting time.
Claim 3
Dependent Claim
84 words
An electronic time-integrating meter as claimed in claim 1, wherein the pulse width modulating means comprises an addition integrator adapted to be switched between alternate reference voltage levels for intervals of time which are related to the magnitude of the input signal and thereby form a pulse signal with pulse width modulation, the correspondence between the pulse width modulated signal and the input signal being such that the time difference between said switching intervals is proportional to the time-integrated value of the input signal.
Claim 4
Dependent Claim
36 words
An electronic time-integrating meter as claimed in claim 2 wherein said gating means is arranged to apply to the counting means the number of clock pulses occurring during the time difference between said switching time intervals.
Claim 5
Dependent Claim
76 words
An electronic time integrating meter as claimed in claim 3 wherein said counting means comprises an additive input and a subtractive input, and wherein said gating means comprises means for applying clock pulses to the additive counter input during one switching time interval and to the subtractive counter input during the other switching time interval, whereby the cumulative number of clock pulses registered by said counting means corresponds to the time-integrated value of the input signal.
Claim 6
Dependent Claim
118 words
An electronic time-integrating meter as claimed in claim 3 wherein said counting means comprises a first cumulative pulse counter with an output indicating the number of pulses counted thereby, a second cumulative pulse counter with an output indicating the number of pulses counted thereby, and subtracting means responsive to the outputs of the first and second counters for deriving the difference between the number of pulses counted by each counter, and wherein Said gating means comprises means for applying clock pulses to said first counter during one switching time interval, and to the second counter during the other switching time interval, whereby the difference signal in said subtracting means corresponds to the time-integrated value of the input signal.
Claim 7
Dependent Claim
120 words
An electronic time-integrating meter as claimed in claim 1, wherein said pulse width modulating means comprises an addition integrator adapted to be switched between alternate reference voltage levels for intervals of time which are related to the magnitude of the input signal, said alternating time intervals thereby providing a signal with pulse width modulation, the correspondence between the pulse width modulated signal and the input signal being such that one switching time interval is directly proportional to the time-integrated value of the input signal, and wherein the gating means is arranged to apply clock pulses to the counting means during said one time interval, whereby the accumulated count in said counting means represents the time-integrated value of the input signal.
Claim 8
Dependent Claim
47 words
An electronic time-integrating meter as claimed in claim 6 wherein said pulse width modulating means includes switching means for alternately connecting and disconnecting a reference voltage to the addition integrator, a threshold comparator responsive to the addition integrator, said switching means being responsive to the threshold comparator.
Claim 9
Dependent Claim
72 words
An electronic time-integrating meter as claimed in claim 7 further comprising synchronous gating means responsive to the threshold comparator and to the clock pulse generator for controlling said switching means, said synchronous gating means being arranged to change its output synchronously with the first clock pulse following a change in output of the threshold comparator, the output of the synchronous gating circuit controlling said switching means and forming said modulated pulse signal.
Claim 10
Dependent Claim
231 words
An electronic time-integrating watt-hour meter arranged to provide an output signal digitally representing units, such as watt-hours, of electrical energy accumulated subsequent to a starting time comprising means responsive to current and voltage for providing a wattage signal varying its amplitude instantaneously with time; pulse width modulating means for converting the wattage signal into a pulse signal in which pulse width varies in correspondence to the amplitude of the wattage signal; and cumulative digital time measuring means responsive to the pulse width modulating means for digitally measuring pulse widths in said modulated pulse signal, for accumulating said digital pulse width measurements occurring subsequent to said starting time, and for indicating the accumulating of pulse width measurements as a digital number representing said units of electrical energy accumulated subsequent to said starting time, said cumulative digital time measuring means including: a clock pulse generator for generating a clock pulse signal with a constant pulse rate, pulse counting means for cumulatively counting clock pulses applied there subsequent to said starting time and for indicating the cumulative count as a digital output signal, and gating means responsive to the modulated pulse signal for applying to the counting means a portion of the clock pulse signal corresponding to the width of the pulses in the modulated pulse signal, whereby the digital signal output of the counting means represents the time-integrated value of the wattage signal.
Claim 11
Dependent Claim
231 words
An electronic time-integrating watt-hour meter arranged to provide an output signal digitally representing units, such as watt-hours, of electrical energy accumulated subsequent to a starting time comprising means responsive to current and voltage for providing a wattage signal varying its amplitude instantaneously with time; pulse width modulating means for converting the wattage signal into a pulse signal in which pulse width varies in correspondence to the amplitude of the wattage signal; and cumulative digital time measuring means responsive to the pulse width modulating means for digitally measuring pulse widths in said modulated pulse signal, for accumulating said digital pulse width measurements occurring subsequent to said starting time, and for indicating the accumulating of pulse width measurements as a digital number representing said units of electrical energy accumulated subsequent to said starting time, said cumulative digital time measuring means including: a clock pulse generator for generating a clock pulse signal with a constant pulse rate, pulse counting means for cumulatively counting clock pulses applied there subsequent to said starting time and for indicating the cumulative count as a digital output signal, and gating means responsive to the modulated pulse signal for applying to the counting means a portion of the clock pulse signal corresponding to the width of the pulses in the modulated pulse signal, whereby the digital signal output of the counting means represents the time-integrated value of the wattage signal.
Claim 12
Dependent Claim
126 words
An electronic time-integrating watt-hour meter as claimed in claim 9, wherein said pulse width modulating means comprises an addition integrator, switching means for alternating between different reference voltage levels to be applied to the addition integrator along with the wattage signal, a triangular reference oscillator, and a voltage comparator for comparing the triangular signals of the reference oscillator with the output of the addition integrator, said switching means beIng responsive to the output signal from the voltage comparator, said output signal forming said modulated pulse signal with successive switching time intervals whose time difference is proportional to the time-integrated value of the wattage signal, said counting means and gating means being arranged to cumulatively count the number of clock pulses which occur during said time difference.
Claim 13
Dependent Claim
64 words
An electronic time-integrating watt-hour meter as claimed in claim 9 wherein said width modulating means comprises an addition integrator, switching means for alternately connecting and disconnecting a reference voltage to the wattage signal at the input of the addition integrator and a threshold comparator responsive to the addition integrators to provide an output signal, said switching means being responsive to the comparator output signal.
Claim 14
Dependent Claim
66 words
An electronic time integrating watt-hour meter as claimed in claim 11, wherein said pulse width modulating means further comprises synchronous gating means responsive to the comparator output signal and to the clock pulse generator for controlling said switching means, said synchronous gating means being arranged to change its output state upon the occurence of the first clock pulse following a change in the comparator output signal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-17 | 1977-12-17 | 1978-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-17 | 1981-12-17 | 1982-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-17 | 1985-12-17 | 1986-06-18 | $7700.00 | Window Closed / Lapsed |