Patent US3581176A successfully refreshed from Google Patents.
US3581176A
Expired / Lapsed
US
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System for driving electric motors
Assignee: Ampex Corp
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Filing: 1968-08-19
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Granted: 1971-05-25
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Expires: 1988-08-19
Abstract
Abstract Closed loop servosystem in which an electric motor is driven by or in accordance with signals representing the difference between the actual speed of the motor and a desired nominal speed only if the actual speed is below the nominal speed. The system comprises means for providing trigger signals of a frequency in accord with motor speed, a bistable circuit which when in one state provides an output signal to drive the motor, means responsive to the trigger signals to put the bistable circuit in said one state after a predetermined time has elapsed from receipt of a trigger signal and to switch the bistable circuit to its other state on receipt of each trigger signal.
Inventors
- 👤 Geoffrey James Bigg
- 👤 Alistair Michael Heaslett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:47
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/29; H02P7/2913; Y; Y10; Y10S; Y10S388/00; Y10S388/907; Y10S388/911; Y10S388/921
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
178 words
A system for maintaining the speed of a motor at a desired nominal value of the kind described comprising, in combination: means for providing reference signals at a rate varying in accordance with the speed of the motor; a timing circuit responsive to the reference signals to initiate the generation of a separate duration representative signal each time a reference signal is received; a bistable circuit when arranged in one state only provides an output signal capable of causing the motor to be driven; means responsive to the duration representative signal when this signal represents a duration of at least a predetermined length to set the bistable in said one state until the next reference signal is received; means responsive to the setting of the bistable circuit in the said one state to condition the timing circuit for the generation of a duration representative signal; and means responsive to the reference signals to condition the timing circuit for the generation of a duration representative signal when the duration between successive reference signals is less than the predetermined length.
Claim 2
Independent Claim
178 words
A system for maintaining the speed of a motor at a desired nominal value of the kind described comprising, in combination: means for providing reference signals at a rate varying in accordance with the speed of the motor; a timing circuit responsive to the reference signals to initiate the generation of a separate duration representative signal each time a reference signal is received; a bistable circuit when arranged in one state only provides an output signal capable of causing the motor to be driven; means responsive to the duration representative signal when this signal represents a duration of at least a predetermined length to set the bistable in said one state until the next reference signal is received; means responsive to the setting of the bistable circuit in the said one state to condition the timing circuit for the generation of a duration representative signal; and means responsive to the reference signals to condition the timing circuit for the generation of a duration representative signal when the duration between successive reference signals is less than the predetermined length.
Claim 3
Dependent Claim
126 words
A system as claimed in claim 1 in which the timing circuit comprises a ramp generator responsive to each of the reference signals to initiate a duration representative signal which varies in amplitude from a datum at a predetermined rate, the predetermined duration of the duration representative signal being the time required for it to reach a predetermined amplitude, the bistable circuit setting means is responsive to the duration representative signal reaching the predetermined amplitude to set the bistable circuit in the said one state, and the ramp generator is responsive to the reference signal responsive means for conditioning the timing circuit to be conditioned for the generation of a duration representative signal when the duration between successive reference signals is less than the predetermined length.
References Cited (Backward Citations)
US3371258A
Cited
US3458792A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |