Patent US4283489A successfully refreshed from Google Patents.
Patent US3553556A successfully refreshed from Google Patents.
US3553556A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for controlling the speed of a motor
Assignee: Individual
•
Filing: 1967-10-11
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Granted: 1971-01-05
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Expires: 1987-10-11
Abstract
Abstract THE THYRISTOR FOR CONTROLLING THE SPEED OF AN A.C. OR D.C. MOTOR HAS ITS FIRING CURRENT SUPPLIED BY A PHASE TIMING CIRCUIT IN WHICH A TACHOMETRIC D.C. VOLTAGE PROPORTIONAL TO MOTOR SPEED IS COMBINED WITH A FIXED REFERENCE VOLTAGE AND APPLIED TO A TIMING CONDENSER THROUGH A VOLTAGE DIVIDER NETWORK SUCH THAT THE "LEAP" VOLTAGE APPLIED TO THE CONDENSER IS A FUNCTION OF THE DIFFERENCE BETWEEN PREDETERMINED FRACTIONS OF SAID REFERNCE VOLTAGE AND SAID TACHOMETRIC D.C. VOLTAGE. AUXILIARY CIRCUITRY LIMITS THE STARTING CURRENT AND THE MAXIMUM OPERATING CURRENT.
Inventors
- 👤 Peter Dosch
- 👤 Manfred Oehmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:13
CPC Classifications
H; H02; H02P; H02P25/00; H02P25/02; H02P25/10; H02P25/14; H02P25/145; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/292; H02P7/295; Y; Y10; Y10S; Y10S388/00; Y10S388/907; Y10S388/917; Y10S388/918
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |