Controlled static convertor for motor control and control angle limiting arrangement
Abstract
Abstract A controlled static convertor has terminals for connection to an alternating current source and includes controlled rectifiers and a control pulse device for delivering control signals to the rectifiers. The control pulse device includes arrangements for affecting the control angle (α) of the rectifiers and for limiting the control angle to an upper limit value. Devices are provided to render the control angle limiting arrangement inactive when the direct current of the convertor is discontinuous. The direct current of the convertor is sensed and, if this current at a time corresponding to the upper limit value of the control angle is less than a predetermined limit value, renders the control angle limiting arrangement inactive.
Inventors
- 👤 Kjell Rehnman
Bibliographic Details
Claims Analysis
Total Claims: 3References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-24 | 1980-02-23 | 1980-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-24 | 1984-02-23 | 1984-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-24 | 1988-02-23 | 1988-08-24 | $7700.00 | Window Closed / Lapsed |