US3694633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arrangement for bumpless transfer of a control system from one mode to another
Assignee: Controle Bailey SA
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Filing: 1970-10-07
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Granted: 1972-09-26
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Expires: 1990-10-07
Abstract
Abstract A bumpless transfer process control having three states of operation, namely a digital control state, an analog control state and a manual control state. The control includes an operational amplifier which produces an analog control signal of the process and includes a first and a second feedback capacitor. A switch operates so that the first capacitor is used as storage for the first and third states of operation and the second capacitor is used as an integrator in the second state. In each state of operation the unused capacitor constantly receives a voltage which charges it to a vlaue which enables it to be used abruptly at any time without producing a surge in the amplifier output signal.
Inventors
- 👤 Jean C Lejon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:30
CPC Classifications
G; G05; G05B; G05B7/00; G05B7/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
246 words
A process control system employing process test variables and process controllers said system comprising: a. a digital control path including means for sampling the process test variables, means for converting the samples of the process test variables into process test digital signals, processor means for forming from said process test digital signals digital control signals and means for converting said digital control signals into analog incremental control signals; b. an analog control path including comparator means for comparing said process test variables to reference signals and forming analog error signals; c. a set of storing and integrating circuits comprising an operational amplifier with a direct and an inverting input, a storage capacitor and an integrating capacitor each having a terminal connected to the output of said amplifier, said storage and integrating circuits being respectively connected to said process controllers; and d. switching means for changing over the digital and analog paths, said switching means in one position comprising means for connecting the analog incremental control signals to the inverting input of said operational amplifier, the other terminal of the storage capacitor to the inverting input of said amplifier, grounding the direct input of said amplifier and connecting the integrating capacitor to the output of the comparator means; and in a second position comprising means for connecting the output of the comparator to the direct input of the operational amplifier, connecting the integrating capacitor to the inverting input of the operational amplifier and grounding the storage capacitor.
Claim 2
Dependent Claim
246 words
A process control system employing process test variables and process controllers said system comprising: a. a digital control path including means for sampling the process test variables, means for converting the samples of the process test variables into process test digital signals, processor means for forming from said process test digital signals digital control signals and means for converting said digital control signals into analog incremental control signals; b. an analog control path including comparator means for comparing said process test variables to reference signals and forming analog error signals; c. a set of storing and integrating circuits comprising an operational amplifier with a direct and an inverting input, a storage capacitor and an integrating capacitor each having a terminal connected to the output of said amplifier, said storage and integrating circuits being respectively connected to said process controllers; and d. switching means for changing over the digital and analog paths, said switching means in one position comprising means for connecting the analog incremental control signals to the inverting input of said operational amplifier, the other terminal of the storage capacitor to the inverting input of said amplifier, grounding the direct input of said amplifier and connecting the integrating capacitor to the output of the comparator means; and in a second position comprising means for connecting the output of the comparator to the direct input of the operational amplifier, connecting the integrating capacitor to the inverting input of the operational amplifier and grounding the storage capacitor.
Claim 3
Dependent Claim
75 words
A process control system as set forth in claim 1 including: a manual control path having a voltage source connected by contactors; and switching means for changing control of the process to said manual path wherein said digital and analog switching means are switched to said first mentioned position and said manual voltage source Is connected to the inverting input of said operational amplifier and said storage capacitor while said analog incremental signal is disconnected.
Claim 4
Dependent Claim
37 words
A process control system as set forth in claim 2 wherein said manual switching means and said digital and analog switching means comprise a switching unit connected between said converting means and said storing and integrating circuits.
Claim 5
Dependent Claim
229 words
A shockless process control system for witching between a fixed value digital-manual common control path and an analog control path, comprising: an operational amplifier having an inverting input, an output and a direct input adapted for connection to said digital-manual common control path and said analog control path; a switching array with a plurality of contacts capable of being switched from a first position to a second position; an integrating capacitor connected between the output of said operational amplifier and said analog control path while the output of said operational amplifier is connected to its inverting input corresponding to a first contact position and said integrating capacitor is connected between the output and the inverting input of said operational amplifier corresponding to a second contact position; a storage capacitor connected between ground and the input of said digital-manual common control path while said common control path is also connected to the direct input of said operational amplifier corresponding to a first contact position and said storage capacitor connected between ground and the output of said operational amplifier while the direct input of said operational amplifier is connected to said analog control path corresponding to a second contact position; and, means for switching said contactor array between said first and second contact positions to provide a shockless transfer between said digital-manual common path and said analog path in either direction.
Claim 6
Dependent Claim
229 words
A shockless process control system for witching between a fixed value digital-manual common control path and an analog control path, comprising: an operational amplifier having an inverting input, an output and a direct input adapted for connection to said digital-manual common control path and said analog control path; a switching array with a plurality of contacts capable of being switched from a first position to a second position; an integrating capacitor connected between the output of said operational amplifier and said analog control path while the output of said operational amplifier is connected to its inverting input corresponding to a first contact position and said integrating capacitor is connected between the output and the inverting input of said operational amplifier corresponding to a second contact position; a storage capacitor connected between ground and the input of said digital-manual common control path while said common control path is also connected to the direct input of said operational amplifier corresponding to a first contact position and said storage capacitor connected between ground and the output of said operational amplifier while the direct input of said operational amplifier is connected to said analog control path corresponding to a second contact position; and, means for switching said contactor array between said first and second contact positions to provide a shockless transfer between said digital-manual common path and said analog path in either direction.
References Cited (Backward Citations)
US3044002A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |