Patent US3207970A successfully refreshed from Google Patents.
US3207970A
Expired / Lapsed
US
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Dual phase d.c. motor speed control system
Assignee: 3M Co
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Filing: 1961-01-09
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Granted: 1965-09-21
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Expires: 1981-01-09
Abstract
No abstract record available.
Inventors
- 👤 Flavio S C Branco
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:27
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/2855; G; G11; G11B; G11B15/00; G11B15/18; G11B15/46; H02P23/00; H02P23/18; H02P23/186; Y; Y10; Y10S; Y10S388/00; Y10S388/90; Y10S388/902
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
164 words
A SPEED CONTROL CIRCUIT FOR A MTOR, INCCLUDING, A SOURCE FOR SUPPLYING A REFERRENCE SIGNAL OF SUBSTANTIALLY CONSTANT FREQUENCY, SIGNAL MEANS COUPLED TO THE MOTOR FOR DEVELOPING A SIGNAL HAVING A VARIABLE FREQUENCY RELATED TO THE INSTANTANEOUS SPEED OF ROTATION OF THE MOTOR, A PHASE DETECTOR COUPLED TO SAID SOURCE AND TO SAID SIGNAL MEANS FOR COMPARING THE PHASE OF THE VARIABLE SIGNAL FROM THE SIGNAL MEANS WITH THE PHASE OF SAID REFERENCE SIGNAL TO PRODUCE AN ERROR SIGNAL HAVING CHARACTERISTICS IN ACCORDINCE WITH THE RESULTS OF SUCH COMPARISON, AN ADJUSTABLE AMPLIFIER HAVING AN ADJUSTABLE GAINN AND COUPLED TO SAID PHASE DETECTOR AND TO SAID MOTOR FOR VARYING THE ENERGY DELIVERED TO SAID MOTOR IN ACCORDANCCE WITH VARIATIONS IN THE CHARRACTERISTICS OF THE ERROR SIGNAL FROM SAID PHASE DETECTOR, AND FREQUENCY RESPONSIVE MEANS COUPLED TO SAID SIGNAL MEANS FOR ADJUSTING THE GAIN OF SAID ADJUSTABLE AMPLIFIER BY PARTICULAR AMOUNTS IN ACCORDANCE WITH VARIATIONNS IN THE FREQUENCY OF THE VARIABLE SIGNAL FROM SAID SIGNAL MEANS.
Claim 2
Dependent Claim
164 words
A SPEED CONTROL CIRCUIT FOR A MTOR, INCCLUDING, A SOURCE FOR SUPPLYING A REFERRENCE SIGNAL OF SUBSTANTIALLY CONSTANT FREQUENCY, SIGNAL MEANS COUPLED TO THE MOTOR FOR DEVELOPING A SIGNAL HAVING A VARIABLE FREQUENCY RELATED TO THE INSTANTANEOUS SPEED OF ROTATION OF THE MOTOR, A PHASE DETECTOR COUPLED TO SAID SOURCE AND TO SAID SIGNAL MEANS FOR COMPARING THE PHASE OF THE VARIABLE SIGNAL FROM THE SIGNAL MEANS WITH THE PHASE OF SAID REFERENCE SIGNAL TO PRODUCE AN ERROR SIGNAL HAVING CHARACTERISTICS IN ACCORDINCE WITH THE RESULTS OF SUCH COMPARISON, AN ADJUSTABLE AMPLIFIER HAVING AN ADJUSTABLE GAINN AND COUPLED TO SAID PHASE DETECTOR AND TO SAID MOTOR FOR VARYING THE ENERGY DELIVERED TO SAID MOTOR IN ACCORDANCCE WITH VARIATIONS IN THE CHARRACTERISTICS OF THE ERROR SIGNAL FROM SAID PHASE DETECTOR, AND FREQUENCY RESPONSIVE MEANS COUPLED TO SAID SIGNAL MEANS FOR ADJUSTING THE GAIN OF SAID ADJUSTABLE AMPLIFIER BY PARTICULAR AMOUNTS IN ACCORDANCE WITH VARIATIONNS IN THE FREQUENCY OF THE VARIABLE SIGNAL FROM SAID SIGNAL MEANS.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-09-20 | 1969-03-22 | 1969-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-09-20 | 1973-03-22 | 1973-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-09-20 | 1977-03-22 | 1977-09-21 | $7700.00 | Window Closed / Lapsed |