Patent US1296451A successfully refreshed from Google Patents.
US3662275A
Expired / Lapsed
US
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Manual/automatic station for use in process control systems
Assignee: General Electric Co
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Filing: 1970-10-01
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Granted: 1972-05-09
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Expires: 1990-10-01
Abstract
Abstract A manual/automatic station including two amplifiers and a switching circuit for interconnecting the amplifiers in either an automatic configuration or a manual configuration. In the automatic configuration, the two amplifiers are in series. In the manual configuration, the output of a circuit associated with the first amplifier receives a feedback current from the station load circuit. A shunt capacitor connected between an input to the first amplifier and the circuit output charges to the difference between a feedback voltage developed in the station load circuit and an automatic control signal. The output of the first amplifier, which becomes saturated in the manual configuration, is limited by Zener diodes. On return to the automatic configuration, the Zener-limited voltage across the shunt capacitor. The current establishes a ramp voltage across the input to the second amplifier and, consequently, across the load until the first amplifier is driven from saturation. The shunt capacitor passes changes in input signals to the second amplifier during ramping.
Inventors
- 👤 John E Riley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:47
CPC Classifications
G; G05; G05B; G05B7/00; G05B7/02
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
219 words
A manual/automatic station connected between a process controller and a load circuit, means for providing a ramp change in load current between a manually controlled load current established while the station is in a manual configuration and an automatically controlled load current established by the process controller when the station is switched to an automatic configuration, comprising: a. a differential amplifier having a first input terminal connected to the output of the process controller, a second input terminal, and an output terminal; b. an output impedance having a first end connected to the output terminal; c. a shunt capacitor connected between a second end of said output impedance and the first input terminal; d. means for connecting the second end of said output impedance in circuit with the load while the station is in the automatic configuration; and e. means for applying a load feedback signal to the second input terminal continually and to the second end of said output impedance only while the station is in the manual configuration, said differential amplifier being driven into saturation when the station is in the manual configuration and being driven from saturation when the station returns to an automatic configuration only after the voltage across said shunt capacitor has been reduced to a predetermined level by current through said output impedance.
Claim 2
Dependent Claim
219 words
A manual/automatic station connected between a process controller and a load circuit, means for providing a ramp change in load current between a manually controlled load current established while the station is in a manual configuration and an automatically controlled load current established by the process controller when the station is switched to an automatic configuration, comprising: a. a differential amplifier having a first input terminal connected to the output of the process controller, a second input terminal, and an output terminal; b. an output impedance having a first end connected to the output terminal; c. a shunt capacitor connected between a second end of said output impedance and the first input terminal; d. means for connecting the second end of said output impedance in circuit with the load while the station is in the automatic configuration; and e. means for applying a load feedback signal to the second input terminal continually and to the second end of said output impedance only while the station is in the manual configuration, said differential amplifier being driven into saturation when the station is in the manual configuration and being driven from saturation when the station returns to an automatic configuration only after the voltage across said shunt capacitor has been reduced to a predetermined level by current through said output impedance.
Claim 3
Dependent Claim
19 words
the second input terminal of said second differential amplifier to the load circuit to receive a feedback signal, and
Claim 4
Dependent Claim
19 words
the second input terminal of said second differential amplifier to the load circuit to receive a feedback signal, and
Claim 5
Dependent Claim
17 words
the second input terminal of said second differential amplifier to the second terminal of said integrating capacitor.
Claim 6
Dependent Claim
17 words
the second input terminal of said second differential amplifier to the second terminal of said integrating capacitor.
Claim 7
Dependent Claim
35 words
A manual/automatic station of the type recited in claim 1 further including means for limiting the output voltage of said differential amplifier during saturation to improve the linearity of the ramp change in load current.
Claim 8
Dependent Claim
39 words
A manual/automatic station of the type recited in claim 2 wherein said voltage-limiting means includes a pair of inversely poled, serially connected voltage breakdown devices connected between the output terminal of said differential amplifier and an electrical ground terminal.
Claim 9
Dependent Claim
29 words
the second terminal of said integrating capacitor to the electrical ground terminal; and e. means for establishing the following electrical connections while the station is in a manual configuration
Claim 10
Dependent Claim
29 words
the second terminal of said integrating capacitor to the electrical ground terminal; and e. means for establishing the following electrical connections while the station is in a manual configuration
Claim 11
Dependent Claim
106 words
A manual/automatic station of the type recited in claim 1 further including a. a second differential amplifier having first and second input terminals and an output terminal connected to the load circuit; b. an integrating capacitor having a first terminal connected to said load circuit for receiving a load feedback signal; c. a manual control current source for selectively altering the level of lOad current while the station is in the manual configuration, the output of said current source being electrically connected to a second terminal of said integrating capacitor; d. means for establishing the following electrical connections while the station is in an automatic configuration
Claim 12
Dependent Claim
35 words
A manual/automatic station of the type recited in claim 4 further including means for limiting the output voltage of said differential amplifier during saturation to improve the linearity of the ramp change in load current.
Claim 13
Dependent Claim
39 words
A manual/automatic station of the type recited in claim 5 wherein said voltage-limiting means includes a pair of inversely poled, serially connected voltage breakdown devices connected between the output terminal of said differential amplifier and an electrical ground terminal.
References Cited (Backward Citations)
US3068387A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |