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US4661765A
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Alternating current load power controller
Assignee: Ricoh Co Ltd
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Filing: 1985-05-17
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Granted: 1987-04-28
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Expires: 2005-05-17
Abstract
Abstract Alternating current electric power fed to a load is controlled to a target value using phase control. During a half cycle of the alternating current waveform, sampling of voltage and square calculation of the sampled value are repeated. During the remaining half cycle, average value calculation based on the result of the above calculation, root calculation and proportional calculation are implemented. Thus, the power control cycle is completed within one cycle of the alternating current waveform. By utilizing a plurality of sampling data, dropped data locating in a non-sampling period therebetween is obtained by interpolation. Sampling starts in synchronism with the energizing start-up phase.
Inventors
- 👤 Toshiro Bando
- 👤 Kiyoto Kozaiku
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:48
CPC Classifications
H; H05; H05B; H05B39/00; H05B39/04; H05B39/08; G; G05; G05F; G05F1/00; G05F1/10; G05F1/12; G05F1/40; G05F1/44; G05F1/45; G05F1/455
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
225 words
An alternating current load power controller comprising: switching means for controlling application of an alternating current voltage applied from an alternating current power source to a load, said power source having a predetermined waveform, said waveform having first and second half cycles; first detection means for generating and electric signal corresponding to said alternating current voltage applied to said load; analog-to-digital conversion means for converting the signal from said first detection means from analog to digital data; second detection means for generating a synchronizing signal in synchronism with the waveform of said alternating current power source; and electronic control means for alternately (1) sampling said digital data of the signal from said analog-to-digital conversion means during a first half cycle of the waveform, and in response to the sampling, calculating a square of said sampled digital form of the signal, (2) calculating the square-root of data resulting from calculating the square of said sampled digital data during a second half cycle of said waveform to derive a square root value, said electronic control means comparing the derived square root value with a preset control value to derive a control signal, said control signal being used to set a switching phase of said switching means, said switching means being controlled in timed relationship with said switching phase and the synchronizing signal from said second detection means.
Claim 2
Dependent Claim
225 words
An alternating current load power controller comprising: switching means for controlling application of an alternating current voltage applied from an alternating current power source to a load, said power source having a predetermined waveform, said waveform having first and second half cycles; first detection means for generating and electric signal corresponding to said alternating current voltage applied to said load; analog-to-digital conversion means for converting the signal from said first detection means from analog to digital data; second detection means for generating a synchronizing signal in synchronism with the waveform of said alternating current power source; and electronic control means for alternately (1) sampling said digital data of the signal from said analog-to-digital conversion means during a first half cycle of the waveform, and in response to the sampling, calculating a square of said sampled digital form of the signal, (2) calculating the square-root of data resulting from calculating the square of said sampled digital data during a second half cycle of said waveform to derive a square root value, said electronic control means comparing the derived square root value with a preset control value to derive a control signal, said control signal being used to set a switching phase of said switching means, said switching means being controlled in timed relationship with said switching phase and the synchronizing signal from said second detection means.
Claim 3
Dependent Claim
34 words
The alternating current load power controller according to claim 1, wherein said electronic control means further comprises means for calculating the square of digital data sampled over several cycles and for averaging the same.
Claim 4
Dependent Claim
37 words
The alternating current load power controller according to claim 1, wherein said electronic control means starts the process of sampling the signal from said first detection means when said alternating current voltage is applied to said load.
Claim 5
Dependent Claim
39 words
The alternating current load power controller according to claim 1, wherein said electronic control means adds or subtracts a predetermined value corresponding to said derived square root value and said preset control value to or from said control signal.
Claim 6
Dependent Claim
43 words
The alternating current load power controller according to claim 1, wherein said electronic control means repeatedly adjusts said control signal by a predetermined adjustment value, until just before the time when the result of said square root calculation exceeds said preset control value.
Claim 7
Dependent Claim
53 words
An alternating current load power controller according to claim 5, wherein said electronic control means judges whether or not the result of said square root calculation exceeds said preset control value, by comparing the difference between the result of said square root calculation and said preset control value with said predetermined adjustment value.
Claim 8
Dependent Claim
38 words
An alternating current load power controller according to claim 1, wherein said electronic control means sets said control value in accordance with information from analog level setting means connected to an input terminal of said analog/digital conversion means.
Claim 9
Dependent Claim
228 words
An alternating current load power controller comprising: switching means for controlling application of an alternating current voltage applied from an alternating current power source to a load, said power source having a predetermined waveform, said waveform having first and second half cycles; first detection means for generating an electric signal corresponding to said alternating current voltage applied to said load; analog-to-digital conversion means for converting the signal from said first detection means from analog to digital form; second detection means for generating a synchronizing signal in synchronism with the wave of said alternating current power source; and electronic control means for alternately (1) sampling said digital form of the signal from said analog-to-digital conversion means during a first half cycle of the waveform, and in response to the sampling, calculating a square of said sampled digital form of the signal, (2) calculating the square-root of data resulting from calculating the square of said sampled digital form during a second half cycle of said waveform to derive a square root value, said electronic control means adding or subtracting the square root value to or from said preset control value to derive a control signal, said control signal being used to set a switching phase of said switching means, said switching means being controlled in timed relationship with said switching phase and the synchronizing signal from said second detection means.
Claim 10
Dependent Claim
228 words
An alternating current load power controller comprising: switching means for controlling application of an alternating current voltage applied from an alternating current power source to a load, said power source having a predetermined waveform, said waveform having first and second half cycles; first detection means for generating an electric signal corresponding to said alternating current voltage applied to said load; analog-to-digital conversion means for converting the signal from said first detection means from analog to digital form; second detection means for generating a synchronizing signal in synchronism with the wave of said alternating current power source; and electronic control means for alternately (1) sampling said digital form of the signal from said analog-to-digital conversion means during a first half cycle of the waveform, and in response to the sampling, calculating a square of said sampled digital form of the signal, (2) calculating the square-root of data resulting from calculating the square of said sampled digital form during a second half cycle of said waveform to derive a square root value, said electronic control means adding or subtracting the square root value to or from said preset control value to derive a control signal, said control signal being used to set a switching phase of said switching means, said switching means being controlled in timed relationship with said switching phase and the synchronizing signal from said second detection means.
Claim 11
Dependent Claim
40 words
An alternating current load power controller according to claim 8, wherein said electronic control means starts the process of sampling the signal from said first detection means in synchronism with the time point when said load starts to be energized.
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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) | 1990-04-27 | 1990-10-27 | 1991-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-27 | 1994-10-27 | 1995-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-27 | 1998-10-27 | 1999-04-28 | $7700.00 | Window Closed / Lapsed |